Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 *
5 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
6 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 *
8 * Originally ported from the -rt patch by:
9 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 *
11 * Based on code in the latency_tracer, that is:
12 *
13 * Copyright (C) 2004-2006 Ingo Molnar
14 * Copyright (C) 2004 Nadia Yvette Chambers
15 */
16
17#include <linux/stop_machine.h>
18#include <linux/clocksource.h>
19#include <linux/sched/task.h>
20#include <linux/kallsyms.h>
21#include <linux/security.h>
22#include <linux/seq_file.h>
23#include <linux/tracefs.h>
24#include <linux/hardirq.h>
25#include <linux/kthread.h>
26#include <linux/uaccess.h>
27#include <linux/bsearch.h>
28#include <linux/module.h>
29#include <linux/ftrace.h>
30#include <linux/sysctl.h>
31#include <linux/slab.h>
32#include <linux/ctype.h>
33#include <linux/sort.h>
34#include <linux/list.h>
35#include <linux/hash.h>
36#include <linux/rcupdate.h>
37#include <linux/kprobes.h>
38
39#include <trace/events/sched.h>
40
41#include <asm/sections.h>
42#include <asm/setup.h>
43
44#include "ftrace_internal.h"
45#include "trace_output.h"
46#include "trace_stat.h"
47
48#define FTRACE_WARN_ON(cond) \
49 ({ \
50 int ___r = cond; \
51 if (WARN_ON(___r)) \
52 ftrace_kill(); \
53 ___r; \
54 })
55
56#define FTRACE_WARN_ON_ONCE(cond) \
57 ({ \
58 int ___r = cond; \
59 if (WARN_ON_ONCE(___r)) \
60 ftrace_kill(); \
61 ___r; \
62 })
63
64/* hash bits for specific function selection */
65#define FTRACE_HASH_BITS 7
66#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
67#define FTRACE_HASH_DEFAULT_BITS 10
68#define FTRACE_HASH_MAX_BITS 12
69
70#ifdef CONFIG_DYNAMIC_FTRACE
71#define INIT_OPS_HASH(opsname) \
72 .func_hash = &opsname.local_hash, \
73 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
74#else
75#define INIT_OPS_HASH(opsname)
76#endif
77
78enum {
79 FTRACE_MODIFY_ENABLE_FL = (1 << 0),
80 FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1),
81};
82
83struct ftrace_ops ftrace_list_end __read_mostly = {
84 .func = ftrace_stub,
85 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
86 INIT_OPS_HASH(ftrace_list_end)
87};
88
89/* ftrace_enabled is a method to turn ftrace on or off */
90int ftrace_enabled __read_mostly;
91static int last_ftrace_enabled;
92
93/* Current function tracing op */
94struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
95/* What to set function_trace_op to */
96static struct ftrace_ops *set_function_trace_op;
97
98static bool ftrace_pids_enabled(struct ftrace_ops *ops)
99{
100 struct trace_array *tr;
101
102 if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
103 return false;
104
105 tr = ops->private;
106
107 return tr->function_pids != NULL;
108}
109
110static void ftrace_update_trampoline(struct ftrace_ops *ops);
111
112/*
113 * ftrace_disabled is set when an anomaly is discovered.
114 * ftrace_disabled is much stronger than ftrace_enabled.
115 */
116static int ftrace_disabled __read_mostly;
117
118DEFINE_MUTEX(ftrace_lock);
119
120struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
121ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
122struct ftrace_ops global_ops;
123
124#if ARCH_SUPPORTS_FTRACE_OPS
125static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
126 struct ftrace_ops *op, struct pt_regs *regs);
127#else
128/* See comment below, where ftrace_ops_list_func is defined */
129static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
130#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
131#endif
132
133static inline void ftrace_ops_init(struct ftrace_ops *ops)
134{
135#ifdef CONFIG_DYNAMIC_FTRACE
136 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
137 mutex_init(&ops->local_hash.regex_lock);
138 ops->func_hash = &ops->local_hash;
139 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
140 }
141#endif
142}
143
144static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
145 struct ftrace_ops *op, struct pt_regs *regs)
146{
147 struct trace_array *tr = op->private;
148
149 if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
150 return;
151
152 op->saved_func(ip, parent_ip, op, regs);
153}
154
155static void ftrace_sync(struct work_struct *work)
156{
157 /*
158 * This function is just a stub to implement a hard force
159 * of synchronize_rcu(). This requires synchronizing
160 * tasks even in userspace and idle.
161 *
162 * Yes, function tracing is rude.
163 */
164}
165
166static void ftrace_sync_ipi(void *data)
167{
168 /* Probably not needed, but do it anyway */
169 smp_rmb();
170}
171
172static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
173{
174 /*
175 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
176 * then it needs to call the list anyway.
177 */
178 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
179 FTRACE_FORCE_LIST_FUNC)
180 return ftrace_ops_list_func;
181
182 return ftrace_ops_get_func(ops);
183}
184
185static void update_ftrace_function(void)
186{
187 ftrace_func_t func;
188
189 /*
190 * Prepare the ftrace_ops that the arch callback will use.
191 * If there's only one ftrace_ops registered, the ftrace_ops_list
192 * will point to the ops we want.
193 */
194 set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
195 lockdep_is_held(&ftrace_lock));
196
197 /* If there's no ftrace_ops registered, just call the stub function */
198 if (set_function_trace_op == &ftrace_list_end) {
199 func = ftrace_stub;
200
201 /*
202 * If we are at the end of the list and this ops is
203 * recursion safe and not dynamic and the arch supports passing ops,
204 * then have the mcount trampoline call the function directly.
205 */
206 } else if (rcu_dereference_protected(ftrace_ops_list->next,
207 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
208 func = ftrace_ops_get_list_func(ftrace_ops_list);
209
210 } else {
211 /* Just use the default ftrace_ops */
212 set_function_trace_op = &ftrace_list_end;
213 func = ftrace_ops_list_func;
214 }
215
216 update_function_graph_func();
217
218 /* If there's no change, then do nothing more here */
219 if (ftrace_trace_function == func)
220 return;
221
222 /*
223 * If we are using the list function, it doesn't care
224 * about the function_trace_ops.
225 */
226 if (func == ftrace_ops_list_func) {
227 ftrace_trace_function = func;
228 /*
229 * Don't even bother setting function_trace_ops,
230 * it would be racy to do so anyway.
231 */
232 return;
233 }
234
235#ifndef CONFIG_DYNAMIC_FTRACE
236 /*
237 * For static tracing, we need to be a bit more careful.
238 * The function change takes affect immediately. Thus,
239 * we need to coorditate the setting of the function_trace_ops
240 * with the setting of the ftrace_trace_function.
241 *
242 * Set the function to the list ops, which will call the
243 * function we want, albeit indirectly, but it handles the
244 * ftrace_ops and doesn't depend on function_trace_op.
245 */
246 ftrace_trace_function = ftrace_ops_list_func;
247 /*
248 * Make sure all CPUs see this. Yes this is slow, but static
249 * tracing is slow and nasty to have enabled.
250 */
251 schedule_on_each_cpu(ftrace_sync);
252 /* Now all cpus are using the list ops. */
253 function_trace_op = set_function_trace_op;
254 /* Make sure the function_trace_op is visible on all CPUs */
255 smp_wmb();
256 /* Nasty way to force a rmb on all cpus */
257 smp_call_function(ftrace_sync_ipi, NULL, 1);
258 /* OK, we are all set to update the ftrace_trace_function now! */
259#endif /* !CONFIG_DYNAMIC_FTRACE */
260
261 ftrace_trace_function = func;
262}
263
264static void add_ftrace_ops(struct ftrace_ops __rcu **list,
265 struct ftrace_ops *ops)
266{
267 rcu_assign_pointer(ops->next, *list);
268
269 /*
270 * We are entering ops into the list but another
271 * CPU might be walking that list. We need to make sure
272 * the ops->next pointer is valid before another CPU sees
273 * the ops pointer included into the list.
274 */
275 rcu_assign_pointer(*list, ops);
276}
277
278static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
279 struct ftrace_ops *ops)
280{
281 struct ftrace_ops **p;
282
283 /*
284 * If we are removing the last function, then simply point
285 * to the ftrace_stub.
286 */
287 if (rcu_dereference_protected(*list,
288 lockdep_is_held(&ftrace_lock)) == ops &&
289 rcu_dereference_protected(ops->next,
290 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
291 *list = &ftrace_list_end;
292 return 0;
293 }
294
295 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
296 if (*p == ops)
297 break;
298
299 if (*p != ops)
300 return -1;
301
302 *p = (*p)->next;
303 return 0;
304}
305
306static void ftrace_update_trampoline(struct ftrace_ops *ops);
307
308int __register_ftrace_function(struct ftrace_ops *ops)
309{
310 if (ops->flags & FTRACE_OPS_FL_DELETED)
311 return -EINVAL;
312
313 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
314 return -EBUSY;
315
316#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
317 /*
318 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
319 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
320 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
321 */
322 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
323 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
324 return -EINVAL;
325
326 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
327 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
328#endif
329
330 if (!core_kernel_data((unsigned long)ops))
331 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
332
333 add_ftrace_ops(&ftrace_ops_list, ops);
334
335 /* Always save the function, and reset at unregistering */
336 ops->saved_func = ops->func;
337
338 if (ftrace_pids_enabled(ops))
339 ops->func = ftrace_pid_func;
340
341 ftrace_update_trampoline(ops);
342
343 if (ftrace_enabled)
344 update_ftrace_function();
345
346 return 0;
347}
348
349int __unregister_ftrace_function(struct ftrace_ops *ops)
350{
351 int ret;
352
353 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
354 return -EBUSY;
355
356 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
357
358 if (ret < 0)
359 return ret;
360
361 if (ftrace_enabled)
362 update_ftrace_function();
363
364 ops->func = ops->saved_func;
365
366 return 0;
367}
368
369static void ftrace_update_pid_func(void)
370{
371 struct ftrace_ops *op;
372
373 /* Only do something if we are tracing something */
374 if (ftrace_trace_function == ftrace_stub)
375 return;
376
377 do_for_each_ftrace_op(op, ftrace_ops_list) {
378 if (op->flags & FTRACE_OPS_FL_PID) {
379 op->func = ftrace_pids_enabled(op) ?
380 ftrace_pid_func : op->saved_func;
381 ftrace_update_trampoline(op);
382 }
383 } while_for_each_ftrace_op(op);
384
385 update_ftrace_function();
386}
387
388#ifdef CONFIG_FUNCTION_PROFILER
389struct ftrace_profile {
390 struct hlist_node node;
391 unsigned long ip;
392 unsigned long counter;
393#ifdef CONFIG_FUNCTION_GRAPH_TRACER
394 unsigned long long time;
395 unsigned long long time_squared;
396#endif
397};
398
399struct ftrace_profile_page {
400 struct ftrace_profile_page *next;
401 unsigned long index;
402 struct ftrace_profile records[];
403};
404
405struct ftrace_profile_stat {
406 atomic_t disabled;
407 struct hlist_head *hash;
408 struct ftrace_profile_page *pages;
409 struct ftrace_profile_page *start;
410 struct tracer_stat stat;
411};
412
413#define PROFILE_RECORDS_SIZE \
414 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
415
416#define PROFILES_PER_PAGE \
417 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
418
419static int ftrace_profile_enabled __read_mostly;
420
421/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
422static DEFINE_MUTEX(ftrace_profile_lock);
423
424static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
425
426#define FTRACE_PROFILE_HASH_BITS 10
427#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
428
429static void *
430function_stat_next(void *v, int idx)
431{
432 struct ftrace_profile *rec = v;
433 struct ftrace_profile_page *pg;
434
435 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
436
437 again:
438 if (idx != 0)
439 rec++;
440
441 if ((void *)rec >= (void *)&pg->records[pg->index]) {
442 pg = pg->next;
443 if (!pg)
444 return NULL;
445 rec = &pg->records[0];
446 if (!rec->counter)
447 goto again;
448 }
449
450 return rec;
451}
452
453static void *function_stat_start(struct tracer_stat *trace)
454{
455 struct ftrace_profile_stat *stat =
456 container_of(trace, struct ftrace_profile_stat, stat);
457
458 if (!stat || !stat->start)
459 return NULL;
460
461 return function_stat_next(&stat->start->records[0], 0);
462}
463
464#ifdef CONFIG_FUNCTION_GRAPH_TRACER
465/* function graph compares on total time */
466static int function_stat_cmp(void *p1, void *p2)
467{
468 struct ftrace_profile *a = p1;
469 struct ftrace_profile *b = p2;
470
471 if (a->time < b->time)
472 return -1;
473 if (a->time > b->time)
474 return 1;
475 else
476 return 0;
477}
478#else
479/* not function graph compares against hits */
480static int function_stat_cmp(void *p1, void *p2)
481{
482 struct ftrace_profile *a = p1;
483 struct ftrace_profile *b = p2;
484
485 if (a->counter < b->counter)
486 return -1;
487 if (a->counter > b->counter)
488 return 1;
489 else
490 return 0;
491}
492#endif
493
494static int function_stat_headers(struct seq_file *m)
495{
496#ifdef CONFIG_FUNCTION_GRAPH_TRACER
497 seq_puts(m, " Function "
498 "Hit Time Avg s^2\n"
499 " -------- "
500 "--- ---- --- ---\n");
501#else
502 seq_puts(m, " Function Hit\n"
503 " -------- ---\n");
504#endif
505 return 0;
506}
507
508static int function_stat_show(struct seq_file *m, void *v)
509{
510 struct ftrace_profile *rec = v;
511 char str[KSYM_SYMBOL_LEN];
512 int ret = 0;
513#ifdef CONFIG_FUNCTION_GRAPH_TRACER
514 static struct trace_seq s;
515 unsigned long long avg;
516 unsigned long long stddev;
517#endif
518 mutex_lock(&ftrace_profile_lock);
519
520 /* we raced with function_profile_reset() */
521 if (unlikely(rec->counter == 0)) {
522 ret = -EBUSY;
523 goto out;
524 }
525
526#ifdef CONFIG_FUNCTION_GRAPH_TRACER
527 avg = rec->time;
528 do_div(avg, rec->counter);
529 if (tracing_thresh && (avg < tracing_thresh))
530 goto out;
531#endif
532
533 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
534 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
535
536#ifdef CONFIG_FUNCTION_GRAPH_TRACER
537 seq_puts(m, " ");
538
539 /* Sample standard deviation (s^2) */
540 if (rec->counter <= 1)
541 stddev = 0;
542 else {
543 /*
544 * Apply Welford's method:
545 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
546 */
547 stddev = rec->counter * rec->time_squared -
548 rec->time * rec->time;
549
550 /*
551 * Divide only 1000 for ns^2 -> us^2 conversion.
552 * trace_print_graph_duration will divide 1000 again.
553 */
554 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
555 }
556
557 trace_seq_init(&s);
558 trace_print_graph_duration(rec->time, &s);
559 trace_seq_puts(&s, " ");
560 trace_print_graph_duration(avg, &s);
561 trace_seq_puts(&s, " ");
562 trace_print_graph_duration(stddev, &s);
563 trace_print_seq(m, &s);
564#endif
565 seq_putc(m, '\n');
566out:
567 mutex_unlock(&ftrace_profile_lock);
568
569 return ret;
570}
571
572static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
573{
574 struct ftrace_profile_page *pg;
575
576 pg = stat->pages = stat->start;
577
578 while (pg) {
579 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
580 pg->index = 0;
581 pg = pg->next;
582 }
583
584 memset(stat->hash, 0,
585 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
586}
587
588int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
589{
590 struct ftrace_profile_page *pg;
591 int functions;
592 int pages;
593 int i;
594
595 /* If we already allocated, do nothing */
596 if (stat->pages)
597 return 0;
598
599 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
600 if (!stat->pages)
601 return -ENOMEM;
602
603#ifdef CONFIG_DYNAMIC_FTRACE
604 functions = ftrace_update_tot_cnt;
605#else
606 /*
607 * We do not know the number of functions that exist because
608 * dynamic tracing is what counts them. With past experience
609 * we have around 20K functions. That should be more than enough.
610 * It is highly unlikely we will execute every function in
611 * the kernel.
612 */
613 functions = 20000;
614#endif
615
616 pg = stat->start = stat->pages;
617
618 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
619
620 for (i = 1; i < pages; i++) {
621 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
622 if (!pg->next)
623 goto out_free;
624 pg = pg->next;
625 }
626
627 return 0;
628
629 out_free:
630 pg = stat->start;
631 while (pg) {
632 unsigned long tmp = (unsigned long)pg;
633
634 pg = pg->next;
635 free_page(tmp);
636 }
637
638 stat->pages = NULL;
639 stat->start = NULL;
640
641 return -ENOMEM;
642}
643
644static int ftrace_profile_init_cpu(int cpu)
645{
646 struct ftrace_profile_stat *stat;
647 int size;
648
649 stat = &per_cpu(ftrace_profile_stats, cpu);
650
651 if (stat->hash) {
652 /* If the profile is already created, simply reset it */
653 ftrace_profile_reset(stat);
654 return 0;
655 }
656
657 /*
658 * We are profiling all functions, but usually only a few thousand
659 * functions are hit. We'll make a hash of 1024 items.
660 */
661 size = FTRACE_PROFILE_HASH_SIZE;
662
663 stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL);
664
665 if (!stat->hash)
666 return -ENOMEM;
667
668 /* Preallocate the function profiling pages */
669 if (ftrace_profile_pages_init(stat) < 0) {
670 kfree(stat->hash);
671 stat->hash = NULL;
672 return -ENOMEM;
673 }
674
675 return 0;
676}
677
678static int ftrace_profile_init(void)
679{
680 int cpu;
681 int ret = 0;
682
683 for_each_possible_cpu(cpu) {
684 ret = ftrace_profile_init_cpu(cpu);
685 if (ret)
686 break;
687 }
688
689 return ret;
690}
691
692/* interrupts must be disabled */
693static struct ftrace_profile *
694ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
695{
696 struct ftrace_profile *rec;
697 struct hlist_head *hhd;
698 unsigned long key;
699
700 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
701 hhd = &stat->hash[key];
702
703 if (hlist_empty(hhd))
704 return NULL;
705
706 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
707 if (rec->ip == ip)
708 return rec;
709 }
710
711 return NULL;
712}
713
714static void ftrace_add_profile(struct ftrace_profile_stat *stat,
715 struct ftrace_profile *rec)
716{
717 unsigned long key;
718
719 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
720 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
721}
722
723/*
724 * The memory is already allocated, this simply finds a new record to use.
725 */
726static struct ftrace_profile *
727ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
728{
729 struct ftrace_profile *rec = NULL;
730
731 /* prevent recursion (from NMIs) */
732 if (atomic_inc_return(&stat->disabled) != 1)
733 goto out;
734
735 /*
736 * Try to find the function again since an NMI
737 * could have added it
738 */
739 rec = ftrace_find_profiled_func(stat, ip);
740 if (rec)
741 goto out;
742
743 if (stat->pages->index == PROFILES_PER_PAGE) {
744 if (!stat->pages->next)
745 goto out;
746 stat->pages = stat->pages->next;
747 }
748
749 rec = &stat->pages->records[stat->pages->index++];
750 rec->ip = ip;
751 ftrace_add_profile(stat, rec);
752
753 out:
754 atomic_dec(&stat->disabled);
755
756 return rec;
757}
758
759static void
760function_profile_call(unsigned long ip, unsigned long parent_ip,
761 struct ftrace_ops *ops, struct pt_regs *regs)
762{
763 struct ftrace_profile_stat *stat;
764 struct ftrace_profile *rec;
765 unsigned long flags;
766
767 if (!ftrace_profile_enabled)
768 return;
769
770 local_irq_save(flags);
771
772 stat = this_cpu_ptr(&ftrace_profile_stats);
773 if (!stat->hash || !ftrace_profile_enabled)
774 goto out;
775
776 rec = ftrace_find_profiled_func(stat, ip);
777 if (!rec) {
778 rec = ftrace_profile_alloc(stat, ip);
779 if (!rec)
780 goto out;
781 }
782
783 rec->counter++;
784 out:
785 local_irq_restore(flags);
786}
787
788#ifdef CONFIG_FUNCTION_GRAPH_TRACER
789static bool fgraph_graph_time = true;
790
791void ftrace_graph_graph_time_control(bool enable)
792{
793 fgraph_graph_time = enable;
794}
795
796static int profile_graph_entry(struct ftrace_graph_ent *trace)
797{
798 struct ftrace_ret_stack *ret_stack;
799
800 function_profile_call(trace->func, 0, NULL, NULL);
801
802 /* If function graph is shutting down, ret_stack can be NULL */
803 if (!current->ret_stack)
804 return 0;
805
806 ret_stack = ftrace_graph_get_ret_stack(current, 0);
807 if (ret_stack)
808 ret_stack->subtime = 0;
809
810 return 1;
811}
812
813static void profile_graph_return(struct ftrace_graph_ret *trace)
814{
815 struct ftrace_ret_stack *ret_stack;
816 struct ftrace_profile_stat *stat;
817 unsigned long long calltime;
818 struct ftrace_profile *rec;
819 unsigned long flags;
820
821 local_irq_save(flags);
822 stat = this_cpu_ptr(&ftrace_profile_stats);
823 if (!stat->hash || !ftrace_profile_enabled)
824 goto out;
825
826 /* If the calltime was zero'd ignore it */
827 if (!trace->calltime)
828 goto out;
829
830 calltime = trace->rettime - trace->calltime;
831
832 if (!fgraph_graph_time) {
833
834 /* Append this call time to the parent time to subtract */
835 ret_stack = ftrace_graph_get_ret_stack(current, 1);
836 if (ret_stack)
837 ret_stack->subtime += calltime;
838
839 ret_stack = ftrace_graph_get_ret_stack(current, 0);
840 if (ret_stack && ret_stack->subtime < calltime)
841 calltime -= ret_stack->subtime;
842 else
843 calltime = 0;
844 }
845
846 rec = ftrace_find_profiled_func(stat, trace->func);
847 if (rec) {
848 rec->time += calltime;
849 rec->time_squared += calltime * calltime;
850 }
851
852 out:
853 local_irq_restore(flags);
854}
855
856static struct fgraph_ops fprofiler_ops = {
857 .entryfunc = &profile_graph_entry,
858 .retfunc = &profile_graph_return,
859};
860
861static int register_ftrace_profiler(void)
862{
863 return register_ftrace_graph(&fprofiler_ops);
864}
865
866static void unregister_ftrace_profiler(void)
867{
868 unregister_ftrace_graph(&fprofiler_ops);
869}
870#else
871static struct ftrace_ops ftrace_profile_ops __read_mostly = {
872 .func = function_profile_call,
873 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
874 INIT_OPS_HASH(ftrace_profile_ops)
875};
876
877static int register_ftrace_profiler(void)
878{
879 return register_ftrace_function(&ftrace_profile_ops);
880}
881
882static void unregister_ftrace_profiler(void)
883{
884 unregister_ftrace_function(&ftrace_profile_ops);
885}
886#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
887
888static ssize_t
889ftrace_profile_write(struct file *filp, const char __user *ubuf,
890 size_t cnt, loff_t *ppos)
891{
892 unsigned long val;
893 int ret;
894
895 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
896 if (ret)
897 return ret;
898
899 val = !!val;
900
901 mutex_lock(&ftrace_profile_lock);
902 if (ftrace_profile_enabled ^ val) {
903 if (val) {
904 ret = ftrace_profile_init();
905 if (ret < 0) {
906 cnt = ret;
907 goto out;
908 }
909
910 ret = register_ftrace_profiler();
911 if (ret < 0) {
912 cnt = ret;
913 goto out;
914 }
915 ftrace_profile_enabled = 1;
916 } else {
917 ftrace_profile_enabled = 0;
918 /*
919 * unregister_ftrace_profiler calls stop_machine
920 * so this acts like an synchronize_rcu.
921 */
922 unregister_ftrace_profiler();
923 }
924 }
925 out:
926 mutex_unlock(&ftrace_profile_lock);
927
928 *ppos += cnt;
929
930 return cnt;
931}
932
933static ssize_t
934ftrace_profile_read(struct file *filp, char __user *ubuf,
935 size_t cnt, loff_t *ppos)
936{
937 char buf[64]; /* big enough to hold a number */
938 int r;
939
940 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
941 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
942}
943
944static const struct file_operations ftrace_profile_fops = {
945 .open = tracing_open_generic,
946 .read = ftrace_profile_read,
947 .write = ftrace_profile_write,
948 .llseek = default_llseek,
949};
950
951/* used to initialize the real stat files */
952static struct tracer_stat function_stats __initdata = {
953 .name = "functions",
954 .stat_start = function_stat_start,
955 .stat_next = function_stat_next,
956 .stat_cmp = function_stat_cmp,
957 .stat_headers = function_stat_headers,
958 .stat_show = function_stat_show
959};
960
961static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
962{
963 struct ftrace_profile_stat *stat;
964 struct dentry *entry;
965 char *name;
966 int ret;
967 int cpu;
968
969 for_each_possible_cpu(cpu) {
970 stat = &per_cpu(ftrace_profile_stats, cpu);
971
972 name = kasprintf(GFP_KERNEL, "function%d", cpu);
973 if (!name) {
974 /*
975 * The files created are permanent, if something happens
976 * we still do not free memory.
977 */
978 WARN(1,
979 "Could not allocate stat file for cpu %d\n",
980 cpu);
981 return;
982 }
983 stat->stat = function_stats;
984 stat->stat.name = name;
985 ret = register_stat_tracer(&stat->stat);
986 if (ret) {
987 WARN(1,
988 "Could not register function stat for cpu %d\n",
989 cpu);
990 kfree(name);
991 return;
992 }
993 }
994
995 entry = tracefs_create_file("function_profile_enabled", 0644,
996 d_tracer, NULL, &ftrace_profile_fops);
997 if (!entry)
998 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
999}
1000
1001#else /* CONFIG_FUNCTION_PROFILER */
1002static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1003{
1004}
1005#endif /* CONFIG_FUNCTION_PROFILER */
1006
1007#ifdef CONFIG_DYNAMIC_FTRACE
1008
1009static struct ftrace_ops *removed_ops;
1010
1011/*
1012 * Set when doing a global update, like enabling all recs or disabling them.
1013 * It is not set when just updating a single ftrace_ops.
1014 */
1015static bool update_all_ops;
1016
1017#ifndef CONFIG_FTRACE_MCOUNT_RECORD
1018# error Dynamic ftrace depends on MCOUNT_RECORD
1019#endif
1020
1021struct ftrace_func_entry {
1022 struct hlist_node hlist;
1023 unsigned long ip;
1024};
1025
1026struct ftrace_func_probe {
1027 struct ftrace_probe_ops *probe_ops;
1028 struct ftrace_ops ops;
1029 struct trace_array *tr;
1030 struct list_head list;
1031 void *data;
1032 int ref;
1033};
1034
1035/*
1036 * We make these constant because no one should touch them,
1037 * but they are used as the default "empty hash", to avoid allocating
1038 * it all the time. These are in a read only section such that if
1039 * anyone does try to modify it, it will cause an exception.
1040 */
1041static const struct hlist_head empty_buckets[1];
1042static const struct ftrace_hash empty_hash = {
1043 .buckets = (struct hlist_head *)empty_buckets,
1044};
1045#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1046
1047struct ftrace_ops global_ops = {
1048 .func = ftrace_stub,
1049 .local_hash.notrace_hash = EMPTY_HASH,
1050 .local_hash.filter_hash = EMPTY_HASH,
1051 INIT_OPS_HASH(global_ops)
1052 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1053 FTRACE_OPS_FL_INITIALIZED |
1054 FTRACE_OPS_FL_PID,
1055};
1056
1057/*
1058 * Used by the stack undwinder to know about dynamic ftrace trampolines.
1059 */
1060struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
1061{
1062 struct ftrace_ops *op = NULL;
1063
1064 /*
1065 * Some of the ops may be dynamically allocated,
1066 * they are freed after a synchronize_rcu().
1067 */
1068 preempt_disable_notrace();
1069
1070 do_for_each_ftrace_op(op, ftrace_ops_list) {
1071 /*
1072 * This is to check for dynamically allocated trampolines.
1073 * Trampolines that are in kernel text will have
1074 * core_kernel_text() return true.
1075 */
1076 if (op->trampoline && op->trampoline_size)
1077 if (addr >= op->trampoline &&
1078 addr < op->trampoline + op->trampoline_size) {
1079 preempt_enable_notrace();
1080 return op;
1081 }
1082 } while_for_each_ftrace_op(op);
1083 preempt_enable_notrace();
1084
1085 return NULL;
1086}
1087
1088/*
1089 * This is used by __kernel_text_address() to return true if the
1090 * address is on a dynamically allocated trampoline that would
1091 * not return true for either core_kernel_text() or
1092 * is_module_text_address().
1093 */
1094bool is_ftrace_trampoline(unsigned long addr)
1095{
1096 return ftrace_ops_trampoline(addr) != NULL;
1097}
1098
1099struct ftrace_page {
1100 struct ftrace_page *next;
1101 struct dyn_ftrace *records;
1102 int index;
1103 int size;
1104};
1105
1106#define ENTRY_SIZE sizeof(struct dyn_ftrace)
1107#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1108
1109/* estimate from running different kernels */
1110#define NR_TO_INIT 10000
1111
1112static struct ftrace_page *ftrace_pages_start;
1113static struct ftrace_page *ftrace_pages;
1114
1115static __always_inline unsigned long
1116ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1117{
1118 if (hash->size_bits > 0)
1119 return hash_long(ip, hash->size_bits);
1120
1121 return 0;
1122}
1123
1124/* Only use this function if ftrace_hash_empty() has already been tested */
1125static __always_inline struct ftrace_func_entry *
1126__ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1127{
1128 unsigned long key;
1129 struct ftrace_func_entry *entry;
1130 struct hlist_head *hhd;
1131
1132 key = ftrace_hash_key(hash, ip);
1133 hhd = &hash->buckets[key];
1134
1135 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1136 if (entry->ip == ip)
1137 return entry;
1138 }
1139 return NULL;
1140}
1141
1142/**
1143 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1144 * @hash: The hash to look at
1145 * @ip: The instruction pointer to test
1146 *
1147 * Search a given @hash to see if a given instruction pointer (@ip)
1148 * exists in it.
1149 *
1150 * Returns the entry that holds the @ip if found. NULL otherwise.
1151 */
1152struct ftrace_func_entry *
1153ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1154{
1155 if (ftrace_hash_empty(hash))
1156 return NULL;
1157
1158 return __ftrace_lookup_ip(hash, ip);
1159}
1160
1161static void __add_hash_entry(struct ftrace_hash *hash,
1162 struct ftrace_func_entry *entry)
1163{
1164 struct hlist_head *hhd;
1165 unsigned long key;
1166
1167 key = ftrace_hash_key(hash, entry->ip);
1168 hhd = &hash->buckets[key];
1169 hlist_add_head(&entry->hlist, hhd);
1170 hash->count++;
1171}
1172
1173static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1174{
1175 struct ftrace_func_entry *entry;
1176
1177 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1178 if (!entry)
1179 return -ENOMEM;
1180
1181 entry->ip = ip;
1182 __add_hash_entry(hash, entry);
1183
1184 return 0;
1185}
1186
1187static void
1188free_hash_entry(struct ftrace_hash *hash,
1189 struct ftrace_func_entry *entry)
1190{
1191 hlist_del(&entry->hlist);
1192 kfree(entry);
1193 hash->count--;
1194}
1195
1196static void
1197remove_hash_entry(struct ftrace_hash *hash,
1198 struct ftrace_func_entry *entry)
1199{
1200 hlist_del_rcu(&entry->hlist);
1201 hash->count--;
1202}
1203
1204static void ftrace_hash_clear(struct ftrace_hash *hash)
1205{
1206 struct hlist_head *hhd;
1207 struct hlist_node *tn;
1208 struct ftrace_func_entry *entry;
1209 int size = 1 << hash->size_bits;
1210 int i;
1211
1212 if (!hash->count)
1213 return;
1214
1215 for (i = 0; i < size; i++) {
1216 hhd = &hash->buckets[i];
1217 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1218 free_hash_entry(hash, entry);
1219 }
1220 FTRACE_WARN_ON(hash->count);
1221}
1222
1223static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1224{
1225 list_del(&ftrace_mod->list);
1226 kfree(ftrace_mod->module);
1227 kfree(ftrace_mod->func);
1228 kfree(ftrace_mod);
1229}
1230
1231static void clear_ftrace_mod_list(struct list_head *head)
1232{
1233 struct ftrace_mod_load *p, *n;
1234
1235 /* stack tracer isn't supported yet */
1236 if (!head)
1237 return;
1238
1239 mutex_lock(&ftrace_lock);
1240 list_for_each_entry_safe(p, n, head, list)
1241 free_ftrace_mod(p);
1242 mutex_unlock(&ftrace_lock);
1243}
1244
1245static void free_ftrace_hash(struct ftrace_hash *hash)
1246{
1247 if (!hash || hash == EMPTY_HASH)
1248 return;
1249 ftrace_hash_clear(hash);
1250 kfree(hash->buckets);
1251 kfree(hash);
1252}
1253
1254static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1255{
1256 struct ftrace_hash *hash;
1257
1258 hash = container_of(rcu, struct ftrace_hash, rcu);
1259 free_ftrace_hash(hash);
1260}
1261
1262static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1263{
1264 if (!hash || hash == EMPTY_HASH)
1265 return;
1266 call_rcu(&hash->rcu, __free_ftrace_hash_rcu);
1267}
1268
1269void ftrace_free_filter(struct ftrace_ops *ops)
1270{
1271 ftrace_ops_init(ops);
1272 free_ftrace_hash(ops->func_hash->filter_hash);
1273 free_ftrace_hash(ops->func_hash->notrace_hash);
1274}
1275
1276static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1277{
1278 struct ftrace_hash *hash;
1279 int size;
1280
1281 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1282 if (!hash)
1283 return NULL;
1284
1285 size = 1 << size_bits;
1286 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1287
1288 if (!hash->buckets) {
1289 kfree(hash);
1290 return NULL;
1291 }
1292
1293 hash->size_bits = size_bits;
1294
1295 return hash;
1296}
1297
1298
1299static int ftrace_add_mod(struct trace_array *tr,
1300 const char *func, const char *module,
1301 int enable)
1302{
1303 struct ftrace_mod_load *ftrace_mod;
1304 struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1305
1306 ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
1307 if (!ftrace_mod)
1308 return -ENOMEM;
1309
1310 ftrace_mod->func = kstrdup(func, GFP_KERNEL);
1311 ftrace_mod->module = kstrdup(module, GFP_KERNEL);
1312 ftrace_mod->enable = enable;
1313
1314 if (!ftrace_mod->func || !ftrace_mod->module)
1315 goto out_free;
1316
1317 list_add(&ftrace_mod->list, mod_head);
1318
1319 return 0;
1320
1321 out_free:
1322 free_ftrace_mod(ftrace_mod);
1323
1324 return -ENOMEM;
1325}
1326
1327static struct ftrace_hash *
1328alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1329{
1330 struct ftrace_func_entry *entry;
1331 struct ftrace_hash *new_hash;
1332 int size;
1333 int ret;
1334 int i;
1335
1336 new_hash = alloc_ftrace_hash(size_bits);
1337 if (!new_hash)
1338 return NULL;
1339
1340 if (hash)
1341 new_hash->flags = hash->flags;
1342
1343 /* Empty hash? */
1344 if (ftrace_hash_empty(hash))
1345 return new_hash;
1346
1347 size = 1 << hash->size_bits;
1348 for (i = 0; i < size; i++) {
1349 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1350 ret = add_hash_entry(new_hash, entry->ip);
1351 if (ret < 0)
1352 goto free_hash;
1353 }
1354 }
1355
1356 FTRACE_WARN_ON(new_hash->count != hash->count);
1357
1358 return new_hash;
1359
1360 free_hash:
1361 free_ftrace_hash(new_hash);
1362 return NULL;
1363}
1364
1365static void
1366ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1367static void
1368ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1369
1370static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1371 struct ftrace_hash *new_hash);
1372
1373static struct ftrace_hash *
1374__ftrace_hash_move(struct ftrace_hash *src)
1375{
1376 struct ftrace_func_entry *entry;
1377 struct hlist_node *tn;
1378 struct hlist_head *hhd;
1379 struct ftrace_hash *new_hash;
1380 int size = src->count;
1381 int bits = 0;
1382 int i;
1383
1384 /*
1385 * If the new source is empty, just return the empty_hash.
1386 */
1387 if (ftrace_hash_empty(src))
1388 return EMPTY_HASH;
1389
1390 /*
1391 * Make the hash size about 1/2 the # found
1392 */
1393 for (size /= 2; size; size >>= 1)
1394 bits++;
1395
1396 /* Don't allocate too much */
1397 if (bits > FTRACE_HASH_MAX_BITS)
1398 bits = FTRACE_HASH_MAX_BITS;
1399
1400 new_hash = alloc_ftrace_hash(bits);
1401 if (!new_hash)
1402 return NULL;
1403
1404 new_hash->flags = src->flags;
1405
1406 size = 1 << src->size_bits;
1407 for (i = 0; i < size; i++) {
1408 hhd = &src->buckets[i];
1409 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1410 remove_hash_entry(src, entry);
1411 __add_hash_entry(new_hash, entry);
1412 }
1413 }
1414
1415 return new_hash;
1416}
1417
1418static int
1419ftrace_hash_move(struct ftrace_ops *ops, int enable,
1420 struct ftrace_hash **dst, struct ftrace_hash *src)
1421{
1422 struct ftrace_hash *new_hash;
1423 int ret;
1424
1425 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1426 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1427 return -EINVAL;
1428
1429 new_hash = __ftrace_hash_move(src);
1430 if (!new_hash)
1431 return -ENOMEM;
1432
1433 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1434 if (enable) {
1435 /* IPMODIFY should be updated only when filter_hash updating */
1436 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1437 if (ret < 0) {
1438 free_ftrace_hash(new_hash);
1439 return ret;
1440 }
1441 }
1442
1443 /*
1444 * Remove the current set, update the hash and add
1445 * them back.
1446 */
1447 ftrace_hash_rec_disable_modify(ops, enable);
1448
1449 rcu_assign_pointer(*dst, new_hash);
1450
1451 ftrace_hash_rec_enable_modify(ops, enable);
1452
1453 return 0;
1454}
1455
1456static bool hash_contains_ip(unsigned long ip,
1457 struct ftrace_ops_hash *hash)
1458{
1459 /*
1460 * The function record is a match if it exists in the filter
1461 * hash and not in the notrace hash. Note, an emty hash is
1462 * considered a match for the filter hash, but an empty
1463 * notrace hash is considered not in the notrace hash.
1464 */
1465 return (ftrace_hash_empty(hash->filter_hash) ||
1466 __ftrace_lookup_ip(hash->filter_hash, ip)) &&
1467 (ftrace_hash_empty(hash->notrace_hash) ||
1468 !__ftrace_lookup_ip(hash->notrace_hash, ip));
1469}
1470
1471/*
1472 * Test the hashes for this ops to see if we want to call
1473 * the ops->func or not.
1474 *
1475 * It's a match if the ip is in the ops->filter_hash or
1476 * the filter_hash does not exist or is empty,
1477 * AND
1478 * the ip is not in the ops->notrace_hash.
1479 *
1480 * This needs to be called with preemption disabled as
1481 * the hashes are freed with call_rcu().
1482 */
1483int
1484ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1485{
1486 struct ftrace_ops_hash hash;
1487 int ret;
1488
1489#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1490 /*
1491 * There's a small race when adding ops that the ftrace handler
1492 * that wants regs, may be called without them. We can not
1493 * allow that handler to be called if regs is NULL.
1494 */
1495 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1496 return 0;
1497#endif
1498
1499 rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1500 rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1501
1502 if (hash_contains_ip(ip, &hash))
1503 ret = 1;
1504 else
1505 ret = 0;
1506
1507 return ret;
1508}
1509
1510/*
1511 * This is a double for. Do not use 'break' to break out of the loop,
1512 * you must use a goto.
1513 */
1514#define do_for_each_ftrace_rec(pg, rec) \
1515 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1516 int _____i; \
1517 for (_____i = 0; _____i < pg->index; _____i++) { \
1518 rec = &pg->records[_____i];
1519
1520#define while_for_each_ftrace_rec() \
1521 } \
1522 }
1523
1524
1525static int ftrace_cmp_recs(const void *a, const void *b)
1526{
1527 const struct dyn_ftrace *key = a;
1528 const struct dyn_ftrace *rec = b;
1529
1530 if (key->flags < rec->ip)
1531 return -1;
1532 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1533 return 1;
1534 return 0;
1535}
1536
1537/**
1538 * ftrace_location_range - return the first address of a traced location
1539 * if it touches the given ip range
1540 * @start: start of range to search.
1541 * @end: end of range to search (inclusive). @end points to the last byte
1542 * to check.
1543 *
1544 * Returns rec->ip if the related ftrace location is a least partly within
1545 * the given address range. That is, the first address of the instruction
1546 * that is either a NOP or call to the function tracer. It checks the ftrace
1547 * internal tables to determine if the address belongs or not.
1548 */
1549unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1550{
1551 struct ftrace_page *pg;
1552 struct dyn_ftrace *rec;
1553 struct dyn_ftrace key;
1554
1555 key.ip = start;
1556 key.flags = end; /* overload flags, as it is unsigned long */
1557
1558 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1559 if (end < pg->records[0].ip ||
1560 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1561 continue;
1562 rec = bsearch(&key, pg->records, pg->index,
1563 sizeof(struct dyn_ftrace),
1564 ftrace_cmp_recs);
1565 if (rec)
1566 return rec->ip;
1567 }
1568
1569 return 0;
1570}
1571
1572/**
1573 * ftrace_location - return true if the ip giving is a traced location
1574 * @ip: the instruction pointer to check
1575 *
1576 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1577 * That is, the instruction that is either a NOP or call to
1578 * the function tracer. It checks the ftrace internal tables to
1579 * determine if the address belongs or not.
1580 */
1581unsigned long ftrace_location(unsigned long ip)
1582{
1583 return ftrace_location_range(ip, ip);
1584}
1585
1586/**
1587 * ftrace_text_reserved - return true if range contains an ftrace location
1588 * @start: start of range to search
1589 * @end: end of range to search (inclusive). @end points to the last byte to check.
1590 *
1591 * Returns 1 if @start and @end contains a ftrace location.
1592 * That is, the instruction that is either a NOP or call to
1593 * the function tracer. It checks the ftrace internal tables to
1594 * determine if the address belongs or not.
1595 */
1596int ftrace_text_reserved(const void *start, const void *end)
1597{
1598 unsigned long ret;
1599
1600 ret = ftrace_location_range((unsigned long)start,
1601 (unsigned long)end);
1602
1603 return (int)!!ret;
1604}
1605
1606/* Test if ops registered to this rec needs regs */
1607static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1608{
1609 struct ftrace_ops *ops;
1610 bool keep_regs = false;
1611
1612 for (ops = ftrace_ops_list;
1613 ops != &ftrace_list_end; ops = ops->next) {
1614 /* pass rec in as regs to have non-NULL val */
1615 if (ftrace_ops_test(ops, rec->ip, rec)) {
1616 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1617 keep_regs = true;
1618 break;
1619 }
1620 }
1621 }
1622
1623 return keep_regs;
1624}
1625
1626static struct ftrace_ops *
1627ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
1628static struct ftrace_ops *
1629ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
1630
1631static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1632 int filter_hash,
1633 bool inc)
1634{
1635 struct ftrace_hash *hash;
1636 struct ftrace_hash *other_hash;
1637 struct ftrace_page *pg;
1638 struct dyn_ftrace *rec;
1639 bool update = false;
1640 int count = 0;
1641 int all = false;
1642
1643 /* Only update if the ops has been registered */
1644 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1645 return false;
1646
1647 /*
1648 * In the filter_hash case:
1649 * If the count is zero, we update all records.
1650 * Otherwise we just update the items in the hash.
1651 *
1652 * In the notrace_hash case:
1653 * We enable the update in the hash.
1654 * As disabling notrace means enabling the tracing,
1655 * and enabling notrace means disabling, the inc variable
1656 * gets inversed.
1657 */
1658 if (filter_hash) {
1659 hash = ops->func_hash->filter_hash;
1660 other_hash = ops->func_hash->notrace_hash;
1661 if (ftrace_hash_empty(hash))
1662 all = true;
1663 } else {
1664 inc = !inc;
1665 hash = ops->func_hash->notrace_hash;
1666 other_hash = ops->func_hash->filter_hash;
1667 /*
1668 * If the notrace hash has no items,
1669 * then there's nothing to do.
1670 */
1671 if (ftrace_hash_empty(hash))
1672 return false;
1673 }
1674
1675 do_for_each_ftrace_rec(pg, rec) {
1676 int in_other_hash = 0;
1677 int in_hash = 0;
1678 int match = 0;
1679
1680 if (rec->flags & FTRACE_FL_DISABLED)
1681 continue;
1682
1683 if (all) {
1684 /*
1685 * Only the filter_hash affects all records.
1686 * Update if the record is not in the notrace hash.
1687 */
1688 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1689 match = 1;
1690 } else {
1691 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1692 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1693
1694 /*
1695 * If filter_hash is set, we want to match all functions
1696 * that are in the hash but not in the other hash.
1697 *
1698 * If filter_hash is not set, then we are decrementing.
1699 * That means we match anything that is in the hash
1700 * and also in the other_hash. That is, we need to turn
1701 * off functions in the other hash because they are disabled
1702 * by this hash.
1703 */
1704 if (filter_hash && in_hash && !in_other_hash)
1705 match = 1;
1706 else if (!filter_hash && in_hash &&
1707 (in_other_hash || ftrace_hash_empty(other_hash)))
1708 match = 1;
1709 }
1710 if (!match)
1711 continue;
1712
1713 if (inc) {
1714 rec->flags++;
1715 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1716 return false;
1717
1718 /*
1719 * If there's only a single callback registered to a
1720 * function, and the ops has a trampoline registered
1721 * for it, then we can call it directly.
1722 */
1723 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1724 rec->flags |= FTRACE_FL_TRAMP;
1725 else
1726 /*
1727 * If we are adding another function callback
1728 * to this function, and the previous had a
1729 * custom trampoline in use, then we need to go
1730 * back to the default trampoline.
1731 */
1732 rec->flags &= ~FTRACE_FL_TRAMP;
1733
1734 /*
1735 * If any ops wants regs saved for this function
1736 * then all ops will get saved regs.
1737 */
1738 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1739 rec->flags |= FTRACE_FL_REGS;
1740 } else {
1741 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1742 return false;
1743 rec->flags--;
1744
1745 /*
1746 * If the rec had REGS enabled and the ops that is
1747 * being removed had REGS set, then see if there is
1748 * still any ops for this record that wants regs.
1749 * If not, we can stop recording them.
1750 */
1751 if (ftrace_rec_count(rec) > 0 &&
1752 rec->flags & FTRACE_FL_REGS &&
1753 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1754 if (!test_rec_ops_needs_regs(rec))
1755 rec->flags &= ~FTRACE_FL_REGS;
1756 }
1757
1758 /*
1759 * The TRAMP needs to be set only if rec count
1760 * is decremented to one, and the ops that is
1761 * left has a trampoline. As TRAMP can only be
1762 * enabled if there is only a single ops attached
1763 * to it.
1764 */
1765 if (ftrace_rec_count(rec) == 1 &&
1766 ftrace_find_tramp_ops_any(rec))
1767 rec->flags |= FTRACE_FL_TRAMP;
1768 else
1769 rec->flags &= ~FTRACE_FL_TRAMP;
1770
1771 /*
1772 * flags will be cleared in ftrace_check_record()
1773 * if rec count is zero.
1774 */
1775 }
1776 count++;
1777
1778 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1779 update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE;
1780
1781 /* Shortcut, if we handled all records, we are done. */
1782 if (!all && count == hash->count)
1783 return update;
1784 } while_for_each_ftrace_rec();
1785
1786 return update;
1787}
1788
1789static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1790 int filter_hash)
1791{
1792 return __ftrace_hash_rec_update(ops, filter_hash, 0);
1793}
1794
1795static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1796 int filter_hash)
1797{
1798 return __ftrace_hash_rec_update(ops, filter_hash, 1);
1799}
1800
1801static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1802 int filter_hash, int inc)
1803{
1804 struct ftrace_ops *op;
1805
1806 __ftrace_hash_rec_update(ops, filter_hash, inc);
1807
1808 if (ops->func_hash != &global_ops.local_hash)
1809 return;
1810
1811 /*
1812 * If the ops shares the global_ops hash, then we need to update
1813 * all ops that are enabled and use this hash.
1814 */
1815 do_for_each_ftrace_op(op, ftrace_ops_list) {
1816 /* Already done */
1817 if (op == ops)
1818 continue;
1819 if (op->func_hash == &global_ops.local_hash)
1820 __ftrace_hash_rec_update(op, filter_hash, inc);
1821 } while_for_each_ftrace_op(op);
1822}
1823
1824static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1825 int filter_hash)
1826{
1827 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1828}
1829
1830static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1831 int filter_hash)
1832{
1833 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1834}
1835
1836/*
1837 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1838 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1839 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1840 * Note that old_hash and new_hash has below meanings
1841 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1842 * - If the hash is EMPTY_HASH, it hits nothing
1843 * - Anything else hits the recs which match the hash entries.
1844 */
1845static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1846 struct ftrace_hash *old_hash,
1847 struct ftrace_hash *new_hash)
1848{
1849 struct ftrace_page *pg;
1850 struct dyn_ftrace *rec, *end = NULL;
1851 int in_old, in_new;
1852
1853 /* Only update if the ops has been registered */
1854 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1855 return 0;
1856
1857 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1858 return 0;
1859
1860 /*
1861 * Since the IPMODIFY is a very address sensitive action, we do not
1862 * allow ftrace_ops to set all functions to new hash.
1863 */
1864 if (!new_hash || !old_hash)
1865 return -EINVAL;
1866
1867 /* Update rec->flags */
1868 do_for_each_ftrace_rec(pg, rec) {
1869
1870 if (rec->flags & FTRACE_FL_DISABLED)
1871 continue;
1872
1873 /* We need to update only differences of filter_hash */
1874 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1875 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1876 if (in_old == in_new)
1877 continue;
1878
1879 if (in_new) {
1880 /* New entries must ensure no others are using it */
1881 if (rec->flags & FTRACE_FL_IPMODIFY)
1882 goto rollback;
1883 rec->flags |= FTRACE_FL_IPMODIFY;
1884 } else /* Removed entry */
1885 rec->flags &= ~FTRACE_FL_IPMODIFY;
1886 } while_for_each_ftrace_rec();
1887
1888 return 0;
1889
1890rollback:
1891 end = rec;
1892
1893 /* Roll back what we did above */
1894 do_for_each_ftrace_rec(pg, rec) {
1895
1896 if (rec->flags & FTRACE_FL_DISABLED)
1897 continue;
1898
1899 if (rec == end)
1900 goto err_out;
1901
1902 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1903 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1904 if (in_old == in_new)
1905 continue;
1906
1907 if (in_new)
1908 rec->flags &= ~FTRACE_FL_IPMODIFY;
1909 else
1910 rec->flags |= FTRACE_FL_IPMODIFY;
1911 } while_for_each_ftrace_rec();
1912
1913err_out:
1914 return -EBUSY;
1915}
1916
1917static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1918{
1919 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1920
1921 if (ftrace_hash_empty(hash))
1922 hash = NULL;
1923
1924 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1925}
1926
1927/* Disabling always succeeds */
1928static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1929{
1930 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1931
1932 if (ftrace_hash_empty(hash))
1933 hash = NULL;
1934
1935 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1936}
1937
1938static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1939 struct ftrace_hash *new_hash)
1940{
1941 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
1942
1943 if (ftrace_hash_empty(old_hash))
1944 old_hash = NULL;
1945
1946 if (ftrace_hash_empty(new_hash))
1947 new_hash = NULL;
1948
1949 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
1950}
1951
1952static void print_ip_ins(const char *fmt, const unsigned char *p)
1953{
1954 int i;
1955
1956 printk(KERN_CONT "%s", fmt);
1957
1958 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1959 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1960}
1961
1962enum ftrace_bug_type ftrace_bug_type;
1963const void *ftrace_expected;
1964
1965static void print_bug_type(void)
1966{
1967 switch (ftrace_bug_type) {
1968 case FTRACE_BUG_UNKNOWN:
1969 break;
1970 case FTRACE_BUG_INIT:
1971 pr_info("Initializing ftrace call sites\n");
1972 break;
1973 case FTRACE_BUG_NOP:
1974 pr_info("Setting ftrace call site to NOP\n");
1975 break;
1976 case FTRACE_BUG_CALL:
1977 pr_info("Setting ftrace call site to call ftrace function\n");
1978 break;
1979 case FTRACE_BUG_UPDATE:
1980 pr_info("Updating ftrace call site to call a different ftrace function\n");
1981 break;
1982 }
1983}
1984
1985/**
1986 * ftrace_bug - report and shutdown function tracer
1987 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1988 * @rec: The record that failed
1989 *
1990 * The arch code that enables or disables the function tracing
1991 * can call ftrace_bug() when it has detected a problem in
1992 * modifying the code. @failed should be one of either:
1993 * EFAULT - if the problem happens on reading the @ip address
1994 * EINVAL - if what is read at @ip is not what was expected
1995 * EPERM - if the problem happens on writing to the @ip address
1996 */
1997void ftrace_bug(int failed, struct dyn_ftrace *rec)
1998{
1999 unsigned long ip = rec ? rec->ip : 0;
2000
2001 switch (failed) {
2002 case -EFAULT:
2003 FTRACE_WARN_ON_ONCE(1);
2004 pr_info("ftrace faulted on modifying ");
2005 print_ip_sym(ip);
2006 break;
2007 case -EINVAL:
2008 FTRACE_WARN_ON_ONCE(1);
2009 pr_info("ftrace failed to modify ");
2010 print_ip_sym(ip);
2011 print_ip_ins(" actual: ", (unsigned char *)ip);
2012 pr_cont("\n");
2013 if (ftrace_expected) {
2014 print_ip_ins(" expected: ", ftrace_expected);
2015 pr_cont("\n");
2016 }
2017 break;
2018 case -EPERM:
2019 FTRACE_WARN_ON_ONCE(1);
2020 pr_info("ftrace faulted on writing ");
2021 print_ip_sym(ip);
2022 break;
2023 default:
2024 FTRACE_WARN_ON_ONCE(1);
2025 pr_info("ftrace faulted on unknown error ");
2026 print_ip_sym(ip);
2027 }
2028 print_bug_type();
2029 if (rec) {
2030 struct ftrace_ops *ops = NULL;
2031
2032 pr_info("ftrace record flags: %lx\n", rec->flags);
2033 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2034 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2035 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2036 ops = ftrace_find_tramp_ops_any(rec);
2037 if (ops) {
2038 do {
2039 pr_cont("\ttramp: %pS (%pS)",
2040 (void *)ops->trampoline,
2041 (void *)ops->func);
2042 ops = ftrace_find_tramp_ops_next(rec, ops);
2043 } while (ops);
2044 } else
2045 pr_cont("\ttramp: ERROR!");
2046
2047 }
2048 ip = ftrace_get_addr_curr(rec);
2049 pr_cont("\n expected tramp: %lx\n", ip);
2050 }
2051}
2052
2053static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
2054{
2055 unsigned long flag = 0UL;
2056
2057 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2058
2059 if (rec->flags & FTRACE_FL_DISABLED)
2060 return FTRACE_UPDATE_IGNORE;
2061
2062 /*
2063 * If we are updating calls:
2064 *
2065 * If the record has a ref count, then we need to enable it
2066 * because someone is using it.
2067 *
2068 * Otherwise we make sure its disabled.
2069 *
2070 * If we are disabling calls, then disable all records that
2071 * are enabled.
2072 */
2073 if (enable && ftrace_rec_count(rec))
2074 flag = FTRACE_FL_ENABLED;
2075
2076 /*
2077 * If enabling and the REGS flag does not match the REGS_EN, or
2078 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2079 * this record. Set flags to fail the compare against ENABLED.
2080 */
2081 if (flag) {
2082 if (!(rec->flags & FTRACE_FL_REGS) !=
2083 !(rec->flags & FTRACE_FL_REGS_EN))
2084 flag |= FTRACE_FL_REGS;
2085
2086 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2087 !(rec->flags & FTRACE_FL_TRAMP_EN))
2088 flag |= FTRACE_FL_TRAMP;
2089 }
2090
2091 /* If the state of this record hasn't changed, then do nothing */
2092 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2093 return FTRACE_UPDATE_IGNORE;
2094
2095 if (flag) {
2096 /* Save off if rec is being enabled (for return value) */
2097 flag ^= rec->flags & FTRACE_FL_ENABLED;
2098
2099 if (update) {
2100 rec->flags |= FTRACE_FL_ENABLED;
2101 if (flag & FTRACE_FL_REGS) {
2102 if (rec->flags & FTRACE_FL_REGS)
2103 rec->flags |= FTRACE_FL_REGS_EN;
2104 else
2105 rec->flags &= ~FTRACE_FL_REGS_EN;
2106 }
2107 if (flag & FTRACE_FL_TRAMP) {
2108 if (rec->flags & FTRACE_FL_TRAMP)
2109 rec->flags |= FTRACE_FL_TRAMP_EN;
2110 else
2111 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2112 }
2113 }
2114
2115 /*
2116 * If this record is being updated from a nop, then
2117 * return UPDATE_MAKE_CALL.
2118 * Otherwise,
2119 * return UPDATE_MODIFY_CALL to tell the caller to convert
2120 * from the save regs, to a non-save regs function or
2121 * vice versa, or from a trampoline call.
2122 */
2123 if (flag & FTRACE_FL_ENABLED) {
2124 ftrace_bug_type = FTRACE_BUG_CALL;
2125 return FTRACE_UPDATE_MAKE_CALL;
2126 }
2127
2128 ftrace_bug_type = FTRACE_BUG_UPDATE;
2129 return FTRACE_UPDATE_MODIFY_CALL;
2130 }
2131
2132 if (update) {
2133 /* If there's no more users, clear all flags */
2134 if (!ftrace_rec_count(rec))
2135 rec->flags = 0;
2136 else
2137 /*
2138 * Just disable the record, but keep the ops TRAMP
2139 * and REGS states. The _EN flags must be disabled though.
2140 */
2141 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2142 FTRACE_FL_REGS_EN);
2143 }
2144
2145 ftrace_bug_type = FTRACE_BUG_NOP;
2146 return FTRACE_UPDATE_MAKE_NOP;
2147}
2148
2149/**
2150 * ftrace_update_record, set a record that now is tracing or not
2151 * @rec: the record to update
2152 * @enable: set to true if the record is tracing, false to force disable
2153 *
2154 * The records that represent all functions that can be traced need
2155 * to be updated when tracing has been enabled.
2156 */
2157int ftrace_update_record(struct dyn_ftrace *rec, bool enable)
2158{
2159 return ftrace_check_record(rec, enable, true);
2160}
2161
2162/**
2163 * ftrace_test_record, check if the record has been enabled or not
2164 * @rec: the record to test
2165 * @enable: set to true to check if enabled, false if it is disabled
2166 *
2167 * The arch code may need to test if a record is already set to
2168 * tracing to determine how to modify the function code that it
2169 * represents.
2170 */
2171int ftrace_test_record(struct dyn_ftrace *rec, bool enable)
2172{
2173 return ftrace_check_record(rec, enable, false);
2174}
2175
2176static struct ftrace_ops *
2177ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2178{
2179 struct ftrace_ops *op;
2180 unsigned long ip = rec->ip;
2181
2182 do_for_each_ftrace_op(op, ftrace_ops_list) {
2183
2184 if (!op->trampoline)
2185 continue;
2186
2187 if (hash_contains_ip(ip, op->func_hash))
2188 return op;
2189 } while_for_each_ftrace_op(op);
2190
2191 return NULL;
2192}
2193
2194static struct ftrace_ops *
2195ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2196 struct ftrace_ops *op)
2197{
2198 unsigned long ip = rec->ip;
2199
2200 while_for_each_ftrace_op(op) {
2201
2202 if (!op->trampoline)
2203 continue;
2204
2205 if (hash_contains_ip(ip, op->func_hash))
2206 return op;
2207 }
2208
2209 return NULL;
2210}
2211
2212static struct ftrace_ops *
2213ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2214{
2215 struct ftrace_ops *op;
2216 unsigned long ip = rec->ip;
2217
2218 /*
2219 * Need to check removed ops first.
2220 * If they are being removed, and this rec has a tramp,
2221 * and this rec is in the ops list, then it would be the
2222 * one with the tramp.
2223 */
2224 if (removed_ops) {
2225 if (hash_contains_ip(ip, &removed_ops->old_hash))
2226 return removed_ops;
2227 }
2228
2229 /*
2230 * Need to find the current trampoline for a rec.
2231 * Now, a trampoline is only attached to a rec if there
2232 * was a single 'ops' attached to it. But this can be called
2233 * when we are adding another op to the rec or removing the
2234 * current one. Thus, if the op is being added, we can
2235 * ignore it because it hasn't attached itself to the rec
2236 * yet.
2237 *
2238 * If an ops is being modified (hooking to different functions)
2239 * then we don't care about the new functions that are being
2240 * added, just the old ones (that are probably being removed).
2241 *
2242 * If we are adding an ops to a function that already is using
2243 * a trampoline, it needs to be removed (trampolines are only
2244 * for single ops connected), then an ops that is not being
2245 * modified also needs to be checked.
2246 */
2247 do_for_each_ftrace_op(op, ftrace_ops_list) {
2248
2249 if (!op->trampoline)
2250 continue;
2251
2252 /*
2253 * If the ops is being added, it hasn't gotten to
2254 * the point to be removed from this tree yet.
2255 */
2256 if (op->flags & FTRACE_OPS_FL_ADDING)
2257 continue;
2258
2259
2260 /*
2261 * If the ops is being modified and is in the old
2262 * hash, then it is probably being removed from this
2263 * function.
2264 */
2265 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2266 hash_contains_ip(ip, &op->old_hash))
2267 return op;
2268 /*
2269 * If the ops is not being added or modified, and it's
2270 * in its normal filter hash, then this must be the one
2271 * we want!
2272 */
2273 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2274 hash_contains_ip(ip, op->func_hash))
2275 return op;
2276
2277 } while_for_each_ftrace_op(op);
2278
2279 return NULL;
2280}
2281
2282static struct ftrace_ops *
2283ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2284{
2285 struct ftrace_ops *op;
2286 unsigned long ip = rec->ip;
2287
2288 do_for_each_ftrace_op(op, ftrace_ops_list) {
2289 /* pass rec in as regs to have non-NULL val */
2290 if (hash_contains_ip(ip, op->func_hash))
2291 return op;
2292 } while_for_each_ftrace_op(op);
2293
2294 return NULL;
2295}
2296
2297/**
2298 * ftrace_get_addr_new - Get the call address to set to
2299 * @rec: The ftrace record descriptor
2300 *
2301 * If the record has the FTRACE_FL_REGS set, that means that it
2302 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2303 * is not not set, then it wants to convert to the normal callback.
2304 *
2305 * Returns the address of the trampoline to set to
2306 */
2307unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2308{
2309 struct ftrace_ops *ops;
2310
2311 /* Trampolines take precedence over regs */
2312 if (rec->flags & FTRACE_FL_TRAMP) {
2313 ops = ftrace_find_tramp_ops_new(rec);
2314 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2315 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2316 (void *)rec->ip, (void *)rec->ip, rec->flags);
2317 /* Ftrace is shutting down, return anything */
2318 return (unsigned long)FTRACE_ADDR;
2319 }
2320 return ops->trampoline;
2321 }
2322
2323 if (rec->flags & FTRACE_FL_REGS)
2324 return (unsigned long)FTRACE_REGS_ADDR;
2325 else
2326 return (unsigned long)FTRACE_ADDR;
2327}
2328
2329/**
2330 * ftrace_get_addr_curr - Get the call address that is already there
2331 * @rec: The ftrace record descriptor
2332 *
2333 * The FTRACE_FL_REGS_EN is set when the record already points to
2334 * a function that saves all the regs. Basically the '_EN' version
2335 * represents the current state of the function.
2336 *
2337 * Returns the address of the trampoline that is currently being called
2338 */
2339unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2340{
2341 struct ftrace_ops *ops;
2342
2343 /* Trampolines take precedence over regs */
2344 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2345 ops = ftrace_find_tramp_ops_curr(rec);
2346 if (FTRACE_WARN_ON(!ops)) {
2347 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2348 (void *)rec->ip, (void *)rec->ip);
2349 /* Ftrace is shutting down, return anything */
2350 return (unsigned long)FTRACE_ADDR;
2351 }
2352 return ops->trampoline;
2353 }
2354
2355 if (rec->flags & FTRACE_FL_REGS_EN)
2356 return (unsigned long)FTRACE_REGS_ADDR;
2357 else
2358 return (unsigned long)FTRACE_ADDR;
2359}
2360
2361static int
2362__ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
2363{
2364 unsigned long ftrace_old_addr;
2365 unsigned long ftrace_addr;
2366 int ret;
2367
2368 ftrace_addr = ftrace_get_addr_new(rec);
2369
2370 /* This needs to be done before we call ftrace_update_record */
2371 ftrace_old_addr = ftrace_get_addr_curr(rec);
2372
2373 ret = ftrace_update_record(rec, enable);
2374
2375 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2376
2377 switch (ret) {
2378 case FTRACE_UPDATE_IGNORE:
2379 return 0;
2380
2381 case FTRACE_UPDATE_MAKE_CALL:
2382 ftrace_bug_type = FTRACE_BUG_CALL;
2383 return ftrace_make_call(rec, ftrace_addr);
2384
2385 case FTRACE_UPDATE_MAKE_NOP:
2386 ftrace_bug_type = FTRACE_BUG_NOP;
2387 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2388
2389 case FTRACE_UPDATE_MODIFY_CALL:
2390 ftrace_bug_type = FTRACE_BUG_UPDATE;
2391 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2392 }
2393
2394 return -1; /* unknown ftrace bug */
2395}
2396
2397void __weak ftrace_replace_code(int mod_flags)
2398{
2399 struct dyn_ftrace *rec;
2400 struct ftrace_page *pg;
2401 bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
2402 int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
2403 int failed;
2404
2405 if (unlikely(ftrace_disabled))
2406 return;
2407
2408 do_for_each_ftrace_rec(pg, rec) {
2409
2410 if (rec->flags & FTRACE_FL_DISABLED)
2411 continue;
2412
2413 failed = __ftrace_replace_code(rec, enable);
2414 if (failed) {
2415 ftrace_bug(failed, rec);
2416 /* Stop processing */
2417 return;
2418 }
2419 if (schedulable)
2420 cond_resched();
2421 } while_for_each_ftrace_rec();
2422}
2423
2424struct ftrace_rec_iter {
2425 struct ftrace_page *pg;
2426 int index;
2427};
2428
2429/**
2430 * ftrace_rec_iter_start, start up iterating over traced functions
2431 *
2432 * Returns an iterator handle that is used to iterate over all
2433 * the records that represent address locations where functions
2434 * are traced.
2435 *
2436 * May return NULL if no records are available.
2437 */
2438struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2439{
2440 /*
2441 * We only use a single iterator.
2442 * Protected by the ftrace_lock mutex.
2443 */
2444 static struct ftrace_rec_iter ftrace_rec_iter;
2445 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2446
2447 iter->pg = ftrace_pages_start;
2448 iter->index = 0;
2449
2450 /* Could have empty pages */
2451 while (iter->pg && !iter->pg->index)
2452 iter->pg = iter->pg->next;
2453
2454 if (!iter->pg)
2455 return NULL;
2456
2457 return iter;
2458}
2459
2460/**
2461 * ftrace_rec_iter_next, get the next record to process.
2462 * @iter: The handle to the iterator.
2463 *
2464 * Returns the next iterator after the given iterator @iter.
2465 */
2466struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2467{
2468 iter->index++;
2469
2470 if (iter->index >= iter->pg->index) {
2471 iter->pg = iter->pg->next;
2472 iter->index = 0;
2473
2474 /* Could have empty pages */
2475 while (iter->pg && !iter->pg->index)
2476 iter->pg = iter->pg->next;
2477 }
2478
2479 if (!iter->pg)
2480 return NULL;
2481
2482 return iter;
2483}
2484
2485/**
2486 * ftrace_rec_iter_record, get the record at the iterator location
2487 * @iter: The current iterator location
2488 *
2489 * Returns the record that the current @iter is at.
2490 */
2491struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2492{
2493 return &iter->pg->records[iter->index];
2494}
2495
2496static int
2497ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2498{
2499 int ret;
2500
2501 if (unlikely(ftrace_disabled))
2502 return 0;
2503
2504 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2505 if (ret) {
2506 ftrace_bug_type = FTRACE_BUG_INIT;
2507 ftrace_bug(ret, rec);
2508 return 0;
2509 }
2510 return 1;
2511}
2512
2513/*
2514 * archs can override this function if they must do something
2515 * before the modifying code is performed.
2516 */
2517int __weak ftrace_arch_code_modify_prepare(void)
2518{
2519 return 0;
2520}
2521
2522/*
2523 * archs can override this function if they must do something
2524 * after the modifying code is performed.
2525 */
2526int __weak ftrace_arch_code_modify_post_process(void)
2527{
2528 return 0;
2529}
2530
2531void ftrace_modify_all_code(int command)
2532{
2533 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2534 int mod_flags = 0;
2535 int err = 0;
2536
2537 if (command & FTRACE_MAY_SLEEP)
2538 mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
2539
2540 /*
2541 * If the ftrace_caller calls a ftrace_ops func directly,
2542 * we need to make sure that it only traces functions it
2543 * expects to trace. When doing the switch of functions,
2544 * we need to update to the ftrace_ops_list_func first
2545 * before the transition between old and new calls are set,
2546 * as the ftrace_ops_list_func will check the ops hashes
2547 * to make sure the ops are having the right functions
2548 * traced.
2549 */
2550 if (update) {
2551 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2552 if (FTRACE_WARN_ON(err))
2553 return;
2554 }
2555
2556 if (command & FTRACE_UPDATE_CALLS)
2557 ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL);
2558 else if (command & FTRACE_DISABLE_CALLS)
2559 ftrace_replace_code(mod_flags);
2560
2561 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2562 function_trace_op = set_function_trace_op;
2563 smp_wmb();
2564 /* If irqs are disabled, we are in stop machine */
2565 if (!irqs_disabled())
2566 smp_call_function(ftrace_sync_ipi, NULL, 1);
2567 err = ftrace_update_ftrace_func(ftrace_trace_function);
2568 if (FTRACE_WARN_ON(err))
2569 return;
2570 }
2571
2572 if (command & FTRACE_START_FUNC_RET)
2573 err = ftrace_enable_ftrace_graph_caller();
2574 else if (command & FTRACE_STOP_FUNC_RET)
2575 err = ftrace_disable_ftrace_graph_caller();
2576 FTRACE_WARN_ON(err);
2577}
2578
2579static int __ftrace_modify_code(void *data)
2580{
2581 int *command = data;
2582
2583 ftrace_modify_all_code(*command);
2584
2585 return 0;
2586}
2587
2588/**
2589 * ftrace_run_stop_machine, go back to the stop machine method
2590 * @command: The command to tell ftrace what to do
2591 *
2592 * If an arch needs to fall back to the stop machine method, the
2593 * it can call this function.
2594 */
2595void ftrace_run_stop_machine(int command)
2596{
2597 stop_machine(__ftrace_modify_code, &command, NULL);
2598}
2599
2600/**
2601 * arch_ftrace_update_code, modify the code to trace or not trace
2602 * @command: The command that needs to be done
2603 *
2604 * Archs can override this function if it does not need to
2605 * run stop_machine() to modify code.
2606 */
2607void __weak arch_ftrace_update_code(int command)
2608{
2609 ftrace_run_stop_machine(command);
2610}
2611
2612static void ftrace_run_update_code(int command)
2613{
2614 int ret;
2615
2616 ret = ftrace_arch_code_modify_prepare();
2617 FTRACE_WARN_ON(ret);
2618 if (ret)
2619 return;
2620
2621 /*
2622 * By default we use stop_machine() to modify the code.
2623 * But archs can do what ever they want as long as it
2624 * is safe. The stop_machine() is the safest, but also
2625 * produces the most overhead.
2626 */
2627 arch_ftrace_update_code(command);
2628
2629 ret = ftrace_arch_code_modify_post_process();
2630 FTRACE_WARN_ON(ret);
2631}
2632
2633static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2634 struct ftrace_ops_hash *old_hash)
2635{
2636 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2637 ops->old_hash.filter_hash = old_hash->filter_hash;
2638 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2639 ftrace_run_update_code(command);
2640 ops->old_hash.filter_hash = NULL;
2641 ops->old_hash.notrace_hash = NULL;
2642 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2643}
2644
2645static ftrace_func_t saved_ftrace_func;
2646static int ftrace_start_up;
2647
2648void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2649{
2650}
2651
2652static void ftrace_startup_enable(int command)
2653{
2654 if (saved_ftrace_func != ftrace_trace_function) {
2655 saved_ftrace_func = ftrace_trace_function;
2656 command |= FTRACE_UPDATE_TRACE_FUNC;
2657 }
2658
2659 if (!command || !ftrace_enabled)
2660 return;
2661
2662 ftrace_run_update_code(command);
2663}
2664
2665static void ftrace_startup_all(int command)
2666{
2667 update_all_ops = true;
2668 ftrace_startup_enable(command);
2669 update_all_ops = false;
2670}
2671
2672int ftrace_startup(struct ftrace_ops *ops, int command)
2673{
2674 int ret;
2675
2676 if (unlikely(ftrace_disabled))
2677 return -ENODEV;
2678
2679 ret = __register_ftrace_function(ops);
2680 if (ret)
2681 return ret;
2682
2683 ftrace_start_up++;
2684
2685 /*
2686 * Note that ftrace probes uses this to start up
2687 * and modify functions it will probe. But we still
2688 * set the ADDING flag for modification, as probes
2689 * do not have trampolines. If they add them in the
2690 * future, then the probes will need to distinguish
2691 * between adding and updating probes.
2692 */
2693 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2694
2695 ret = ftrace_hash_ipmodify_enable(ops);
2696 if (ret < 0) {
2697 /* Rollback registration process */
2698 __unregister_ftrace_function(ops);
2699 ftrace_start_up--;
2700 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2701 return ret;
2702 }
2703
2704 if (ftrace_hash_rec_enable(ops, 1))
2705 command |= FTRACE_UPDATE_CALLS;
2706
2707 ftrace_startup_enable(command);
2708
2709 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2710
2711 return 0;
2712}
2713
2714int ftrace_shutdown(struct ftrace_ops *ops, int command)
2715{
2716 int ret;
2717
2718 if (unlikely(ftrace_disabled))
2719 return -ENODEV;
2720
2721 ret = __unregister_ftrace_function(ops);
2722 if (ret)
2723 return ret;
2724
2725 ftrace_start_up--;
2726 /*
2727 * Just warn in case of unbalance, no need to kill ftrace, it's not
2728 * critical but the ftrace_call callers may be never nopped again after
2729 * further ftrace uses.
2730 */
2731 WARN_ON_ONCE(ftrace_start_up < 0);
2732
2733 /* Disabling ipmodify never fails */
2734 ftrace_hash_ipmodify_disable(ops);
2735
2736 if (ftrace_hash_rec_disable(ops, 1))
2737 command |= FTRACE_UPDATE_CALLS;
2738
2739 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2740
2741 if (saved_ftrace_func != ftrace_trace_function) {
2742 saved_ftrace_func = ftrace_trace_function;
2743 command |= FTRACE_UPDATE_TRACE_FUNC;
2744 }
2745
2746 if (!command || !ftrace_enabled) {
2747 /*
2748 * If these are dynamic or per_cpu ops, they still
2749 * need their data freed. Since, function tracing is
2750 * not currently active, we can just free them
2751 * without synchronizing all CPUs.
2752 */
2753 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
2754 goto free_ops;
2755
2756 return 0;
2757 }
2758
2759 /*
2760 * If the ops uses a trampoline, then it needs to be
2761 * tested first on update.
2762 */
2763 ops->flags |= FTRACE_OPS_FL_REMOVING;
2764 removed_ops = ops;
2765
2766 /* The trampoline logic checks the old hashes */
2767 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2768 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2769
2770 ftrace_run_update_code(command);
2771
2772 /*
2773 * If there's no more ops registered with ftrace, run a
2774 * sanity check to make sure all rec flags are cleared.
2775 */
2776 if (rcu_dereference_protected(ftrace_ops_list,
2777 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
2778 struct ftrace_page *pg;
2779 struct dyn_ftrace *rec;
2780
2781 do_for_each_ftrace_rec(pg, rec) {
2782 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
2783 pr_warn(" %pS flags:%lx\n",
2784 (void *)rec->ip, rec->flags);
2785 } while_for_each_ftrace_rec();
2786 }
2787
2788 ops->old_hash.filter_hash = NULL;
2789 ops->old_hash.notrace_hash = NULL;
2790
2791 removed_ops = NULL;
2792 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2793
2794 /*
2795 * Dynamic ops may be freed, we must make sure that all
2796 * callers are done before leaving this function.
2797 * The same goes for freeing the per_cpu data of the per_cpu
2798 * ops.
2799 */
2800 if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
2801 /*
2802 * We need to do a hard force of sched synchronization.
2803 * This is because we use preempt_disable() to do RCU, but
2804 * the function tracers can be called where RCU is not watching
2805 * (like before user_exit()). We can not rely on the RCU
2806 * infrastructure to do the synchronization, thus we must do it
2807 * ourselves.
2808 */
2809 schedule_on_each_cpu(ftrace_sync);
2810
2811 /*
2812 * When the kernel is preeptive, tasks can be preempted
2813 * while on a ftrace trampoline. Just scheduling a task on
2814 * a CPU is not good enough to flush them. Calling
2815 * synchornize_rcu_tasks() will wait for those tasks to
2816 * execute and either schedule voluntarily or enter user space.
2817 */
2818 if (IS_ENABLED(CONFIG_PREEMPTION))
2819 synchronize_rcu_tasks();
2820
2821 free_ops:
2822 arch_ftrace_trampoline_free(ops);
2823 }
2824
2825 return 0;
2826}
2827
2828static void ftrace_startup_sysctl(void)
2829{
2830 int command;
2831
2832 if (unlikely(ftrace_disabled))
2833 return;
2834
2835 /* Force update next time */
2836 saved_ftrace_func = NULL;
2837 /* ftrace_start_up is true if we want ftrace running */
2838 if (ftrace_start_up) {
2839 command = FTRACE_UPDATE_CALLS;
2840 if (ftrace_graph_active)
2841 command |= FTRACE_START_FUNC_RET;
2842 ftrace_startup_enable(command);
2843 }
2844}
2845
2846static void ftrace_shutdown_sysctl(void)
2847{
2848 int command;
2849
2850 if (unlikely(ftrace_disabled))
2851 return;
2852
2853 /* ftrace_start_up is true if ftrace is running */
2854 if (ftrace_start_up) {
2855 command = FTRACE_DISABLE_CALLS;
2856 if (ftrace_graph_active)
2857 command |= FTRACE_STOP_FUNC_RET;
2858 ftrace_run_update_code(command);
2859 }
2860}
2861
2862static u64 ftrace_update_time;
2863unsigned long ftrace_update_tot_cnt;
2864
2865static inline int ops_traces_mod(struct ftrace_ops *ops)
2866{
2867 /*
2868 * Filter_hash being empty will default to trace module.
2869 * But notrace hash requires a test of individual module functions.
2870 */
2871 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2872 ftrace_hash_empty(ops->func_hash->notrace_hash);
2873}
2874
2875/*
2876 * Check if the current ops references the record.
2877 *
2878 * If the ops traces all functions, then it was already accounted for.
2879 * If the ops does not trace the current record function, skip it.
2880 * If the ops ignores the function via notrace filter, skip it.
2881 */
2882static inline bool
2883ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2884{
2885 /* If ops isn't enabled, ignore it */
2886 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2887 return false;
2888
2889 /* If ops traces all then it includes this function */
2890 if (ops_traces_mod(ops))
2891 return true;
2892
2893 /* The function must be in the filter */
2894 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2895 !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2896 return false;
2897
2898 /* If in notrace hash, we ignore it too */
2899 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2900 return false;
2901
2902 return true;
2903}
2904
2905static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2906{
2907 struct ftrace_page *pg;
2908 struct dyn_ftrace *p;
2909 u64 start, stop;
2910 unsigned long update_cnt = 0;
2911 unsigned long rec_flags = 0;
2912 int i;
2913
2914 start = ftrace_now(raw_smp_processor_id());
2915
2916 /*
2917 * When a module is loaded, this function is called to convert
2918 * the calls to mcount in its text to nops, and also to create
2919 * an entry in the ftrace data. Now, if ftrace is activated
2920 * after this call, but before the module sets its text to
2921 * read-only, the modification of enabling ftrace can fail if
2922 * the read-only is done while ftrace is converting the calls.
2923 * To prevent this, the module's records are set as disabled
2924 * and will be enabled after the call to set the module's text
2925 * to read-only.
2926 */
2927 if (mod)
2928 rec_flags |= FTRACE_FL_DISABLED;
2929
2930 for (pg = new_pgs; pg; pg = pg->next) {
2931
2932 for (i = 0; i < pg->index; i++) {
2933
2934 /* If something went wrong, bail without enabling anything */
2935 if (unlikely(ftrace_disabled))
2936 return -1;
2937
2938 p = &pg->records[i];
2939 p->flags = rec_flags;
2940
2941 /*
2942 * Do the initial record conversion from mcount jump
2943 * to the NOP instructions.
2944 */
2945 if (!__is_defined(CC_USING_NOP_MCOUNT) &&
2946 !ftrace_code_disable(mod, p))
2947 break;
2948
2949 update_cnt++;
2950 }
2951 }
2952
2953 stop = ftrace_now(raw_smp_processor_id());
2954 ftrace_update_time = stop - start;
2955 ftrace_update_tot_cnt += update_cnt;
2956
2957 return 0;
2958}
2959
2960static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2961{
2962 int order;
2963 int cnt;
2964
2965 if (WARN_ON(!count))
2966 return -EINVAL;
2967
2968 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2969
2970 /*
2971 * We want to fill as much as possible. No more than a page
2972 * may be empty.
2973 */
2974 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2975 order--;
2976
2977 again:
2978 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2979
2980 if (!pg->records) {
2981 /* if we can't allocate this size, try something smaller */
2982 if (!order)
2983 return -ENOMEM;
2984 order >>= 1;
2985 goto again;
2986 }
2987
2988 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2989 pg->size = cnt;
2990
2991 if (cnt > count)
2992 cnt = count;
2993
2994 return cnt;
2995}
2996
2997static struct ftrace_page *
2998ftrace_allocate_pages(unsigned long num_to_init)
2999{
3000 struct ftrace_page *start_pg;
3001 struct ftrace_page *pg;
3002 int order;
3003 int cnt;
3004
3005 if (!num_to_init)
3006 return NULL;
3007
3008 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3009 if (!pg)
3010 return NULL;
3011
3012 /*
3013 * Try to allocate as much as possible in one continues
3014 * location that fills in all of the space. We want to
3015 * waste as little space as possible.
3016 */
3017 for (;;) {
3018 cnt = ftrace_allocate_records(pg, num_to_init);
3019 if (cnt < 0)
3020 goto free_pages;
3021
3022 num_to_init -= cnt;
3023 if (!num_to_init)
3024 break;
3025
3026 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3027 if (!pg->next)
3028 goto free_pages;
3029
3030 pg = pg->next;
3031 }
3032
3033 return start_pg;
3034
3035 free_pages:
3036 pg = start_pg;
3037 while (pg) {
3038 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3039 free_pages((unsigned long)pg->records, order);
3040 start_pg = pg->next;
3041 kfree(pg);
3042 pg = start_pg;
3043 }
3044 pr_info("ftrace: FAILED to allocate memory for functions\n");
3045 return NULL;
3046}
3047
3048#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3049
3050struct ftrace_iterator {
3051 loff_t pos;
3052 loff_t func_pos;
3053 loff_t mod_pos;
3054 struct ftrace_page *pg;
3055 struct dyn_ftrace *func;
3056 struct ftrace_func_probe *probe;
3057 struct ftrace_func_entry *probe_entry;
3058 struct trace_parser parser;
3059 struct ftrace_hash *hash;
3060 struct ftrace_ops *ops;
3061 struct trace_array *tr;
3062 struct list_head *mod_list;
3063 int pidx;
3064 int idx;
3065 unsigned flags;
3066};
3067
3068static void *
3069t_probe_next(struct seq_file *m, loff_t *pos)
3070{
3071 struct ftrace_iterator *iter = m->private;
3072 struct trace_array *tr = iter->ops->private;
3073 struct list_head *func_probes;
3074 struct ftrace_hash *hash;
3075 struct list_head *next;
3076 struct hlist_node *hnd = NULL;
3077 struct hlist_head *hhd;
3078 int size;
3079
3080 (*pos)++;
3081 iter->pos = *pos;
3082
3083 if (!tr)
3084 return NULL;
3085
3086 func_probes = &tr->func_probes;
3087 if (list_empty(func_probes))
3088 return NULL;
3089
3090 if (!iter->probe) {
3091 next = func_probes->next;
3092 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3093 }
3094
3095 if (iter->probe_entry)
3096 hnd = &iter->probe_entry->hlist;
3097
3098 hash = iter->probe->ops.func_hash->filter_hash;
3099
3100 /*
3101 * A probe being registered may temporarily have an empty hash
3102 * and it's at the end of the func_probes list.
3103 */
3104 if (!hash || hash == EMPTY_HASH)
3105 return NULL;
3106
3107 size = 1 << hash->size_bits;
3108
3109 retry:
3110 if (iter->pidx >= size) {
3111 if (iter->probe->list.next == func_probes)
3112 return NULL;
3113 next = iter->probe->list.next;
3114 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3115 hash = iter->probe->ops.func_hash->filter_hash;
3116 size = 1 << hash->size_bits;
3117 iter->pidx = 0;
3118 }
3119
3120 hhd = &hash->buckets[iter->pidx];
3121
3122 if (hlist_empty(hhd)) {
3123 iter->pidx++;
3124 hnd = NULL;
3125 goto retry;
3126 }
3127
3128 if (!hnd)
3129 hnd = hhd->first;
3130 else {
3131 hnd = hnd->next;
3132 if (!hnd) {
3133 iter->pidx++;
3134 goto retry;
3135 }
3136 }
3137
3138 if (WARN_ON_ONCE(!hnd))
3139 return NULL;
3140
3141 iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3142
3143 return iter;
3144}
3145
3146static void *t_probe_start(struct seq_file *m, loff_t *pos)
3147{
3148 struct ftrace_iterator *iter = m->private;
3149 void *p = NULL;
3150 loff_t l;
3151
3152 if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3153 return NULL;
3154
3155 if (iter->mod_pos > *pos)
3156 return NULL;
3157
3158 iter->probe = NULL;
3159 iter->probe_entry = NULL;
3160 iter->pidx = 0;
3161 for (l = 0; l <= (*pos - iter->mod_pos); ) {
3162 p = t_probe_next(m, &l);
3163 if (!p)
3164 break;
3165 }
3166 if (!p)
3167 return NULL;
3168
3169 /* Only set this if we have an item */
3170 iter->flags |= FTRACE_ITER_PROBE;
3171
3172 return iter;
3173}
3174
3175static int
3176t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3177{
3178 struct ftrace_func_entry *probe_entry;
3179 struct ftrace_probe_ops *probe_ops;
3180 struct ftrace_func_probe *probe;
3181
3182 probe = iter->probe;
3183 probe_entry = iter->probe_entry;
3184
3185 if (WARN_ON_ONCE(!probe || !probe_entry))
3186 return -EIO;
3187
3188 probe_ops = probe->probe_ops;
3189
3190 if (probe_ops->print)
3191 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3192
3193 seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3194 (void *)probe_ops->func);
3195
3196 return 0;
3197}
3198
3199static void *
3200t_mod_next(struct seq_file *m, loff_t *pos)
3201{
3202 struct ftrace_iterator *iter = m->private;
3203 struct trace_array *tr = iter->tr;
3204
3205 (*pos)++;
3206 iter->pos = *pos;
3207
3208 iter->mod_list = iter->mod_list->next;
3209
3210 if (iter->mod_list == &tr->mod_trace ||
3211 iter->mod_list == &tr->mod_notrace) {
3212 iter->flags &= ~FTRACE_ITER_MOD;
3213 return NULL;
3214 }
3215
3216 iter->mod_pos = *pos;
3217
3218 return iter;
3219}
3220
3221static void *t_mod_start(struct seq_file *m, loff_t *pos)
3222{
3223 struct ftrace_iterator *iter = m->private;
3224 void *p = NULL;
3225 loff_t l;
3226
3227 if (iter->func_pos > *pos)
3228 return NULL;
3229
3230 iter->mod_pos = iter->func_pos;
3231
3232 /* probes are only available if tr is set */
3233 if (!iter->tr)
3234 return NULL;
3235
3236 for (l = 0; l <= (*pos - iter->func_pos); ) {
3237 p = t_mod_next(m, &l);
3238 if (!p)
3239 break;
3240 }
3241 if (!p) {
3242 iter->flags &= ~FTRACE_ITER_MOD;
3243 return t_probe_start(m, pos);
3244 }
3245
3246 /* Only set this if we have an item */
3247 iter->flags |= FTRACE_ITER_MOD;
3248
3249 return iter;
3250}
3251
3252static int
3253t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3254{
3255 struct ftrace_mod_load *ftrace_mod;
3256 struct trace_array *tr = iter->tr;
3257
3258 if (WARN_ON_ONCE(!iter->mod_list) ||
3259 iter->mod_list == &tr->mod_trace ||
3260 iter->mod_list == &tr->mod_notrace)
3261 return -EIO;
3262
3263 ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3264
3265 if (ftrace_mod->func)
3266 seq_printf(m, "%s", ftrace_mod->func);
3267 else
3268 seq_putc(m, '*');
3269
3270 seq_printf(m, ":mod:%s\n", ftrace_mod->module);
3271
3272 return 0;
3273}
3274
3275static void *
3276t_func_next(struct seq_file *m, loff_t *pos)
3277{
3278 struct ftrace_iterator *iter = m->private;
3279 struct dyn_ftrace *rec = NULL;
3280
3281 (*pos)++;
3282
3283 retry:
3284 if (iter->idx >= iter->pg->index) {
3285 if (iter->pg->next) {
3286 iter->pg = iter->pg->next;
3287 iter->idx = 0;
3288 goto retry;
3289 }
3290 } else {
3291 rec = &iter->pg->records[iter->idx++];
3292 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3293 !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3294
3295 ((iter->flags & FTRACE_ITER_ENABLED) &&
3296 !(rec->flags & FTRACE_FL_ENABLED))) {
3297
3298 rec = NULL;
3299 goto retry;
3300 }
3301 }
3302
3303 if (!rec)
3304 return NULL;
3305
3306 iter->pos = iter->func_pos = *pos;
3307 iter->func = rec;
3308
3309 return iter;
3310}
3311
3312static void *
3313t_next(struct seq_file *m, void *v, loff_t *pos)
3314{
3315 struct ftrace_iterator *iter = m->private;
3316 loff_t l = *pos; /* t_probe_start() must use original pos */
3317 void *ret;
3318
3319 if (unlikely(ftrace_disabled))
3320 return NULL;
3321
3322 if (iter->flags & FTRACE_ITER_PROBE)
3323 return t_probe_next(m, pos);
3324
3325 if (iter->flags & FTRACE_ITER_MOD)
3326 return t_mod_next(m, pos);
3327
3328 if (iter->flags & FTRACE_ITER_PRINTALL) {
3329 /* next must increment pos, and t_probe_start does not */
3330 (*pos)++;
3331 return t_mod_start(m, &l);
3332 }
3333
3334 ret = t_func_next(m, pos);
3335
3336 if (!ret)
3337 return t_mod_start(m, &l);
3338
3339 return ret;
3340}
3341
3342static void reset_iter_read(struct ftrace_iterator *iter)
3343{
3344 iter->pos = 0;
3345 iter->func_pos = 0;
3346 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3347}
3348
3349static void *t_start(struct seq_file *m, loff_t *pos)
3350{
3351 struct ftrace_iterator *iter = m->private;
3352 void *p = NULL;
3353 loff_t l;
3354
3355 mutex_lock(&ftrace_lock);
3356
3357 if (unlikely(ftrace_disabled))
3358 return NULL;
3359
3360 /*
3361 * If an lseek was done, then reset and start from beginning.
3362 */
3363 if (*pos < iter->pos)
3364 reset_iter_read(iter);
3365
3366 /*
3367 * For set_ftrace_filter reading, if we have the filter
3368 * off, we can short cut and just print out that all
3369 * functions are enabled.
3370 */
3371 if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3372 ftrace_hash_empty(iter->hash)) {
3373 iter->func_pos = 1; /* Account for the message */
3374 if (*pos > 0)
3375 return t_mod_start(m, pos);
3376 iter->flags |= FTRACE_ITER_PRINTALL;
3377 /* reset in case of seek/pread */
3378 iter->flags &= ~FTRACE_ITER_PROBE;
3379 return iter;
3380 }
3381
3382 if (iter->flags & FTRACE_ITER_MOD)
3383 return t_mod_start(m, pos);
3384
3385 /*
3386 * Unfortunately, we need to restart at ftrace_pages_start
3387 * every time we let go of the ftrace_mutex. This is because
3388 * those pointers can change without the lock.
3389 */
3390 iter->pg = ftrace_pages_start;
3391 iter->idx = 0;
3392 for (l = 0; l <= *pos; ) {
3393 p = t_func_next(m, &l);
3394 if (!p)
3395 break;
3396 }
3397
3398 if (!p)
3399 return t_mod_start(m, pos);
3400
3401 return iter;
3402}
3403
3404static void t_stop(struct seq_file *m, void *p)
3405{
3406 mutex_unlock(&ftrace_lock);
3407}
3408
3409void * __weak
3410arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3411{
3412 return NULL;
3413}
3414
3415static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3416 struct dyn_ftrace *rec)
3417{
3418 void *ptr;
3419
3420 ptr = arch_ftrace_trampoline_func(ops, rec);
3421 if (ptr)
3422 seq_printf(m, " ->%pS", ptr);
3423}
3424
3425static int t_show(struct seq_file *m, void *v)
3426{
3427 struct ftrace_iterator *iter = m->private;
3428 struct dyn_ftrace *rec;
3429
3430 if (iter->flags & FTRACE_ITER_PROBE)
3431 return t_probe_show(m, iter);
3432
3433 if (iter->flags & FTRACE_ITER_MOD)
3434 return t_mod_show(m, iter);
3435
3436 if (iter->flags & FTRACE_ITER_PRINTALL) {
3437 if (iter->flags & FTRACE_ITER_NOTRACE)
3438 seq_puts(m, "#### no functions disabled ####\n");
3439 else
3440 seq_puts(m, "#### all functions enabled ####\n");
3441 return 0;
3442 }
3443
3444 rec = iter->func;
3445
3446 if (!rec)
3447 return 0;
3448
3449 seq_printf(m, "%ps", (void *)rec->ip);
3450 if (iter->flags & FTRACE_ITER_ENABLED) {
3451 struct ftrace_ops *ops;
3452
3453 seq_printf(m, " (%ld)%s%s",
3454 ftrace_rec_count(rec),
3455 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3456 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
3457 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3458 ops = ftrace_find_tramp_ops_any(rec);
3459 if (ops) {
3460 do {
3461 seq_printf(m, "\ttramp: %pS (%pS)",
3462 (void *)ops->trampoline,
3463 (void *)ops->func);
3464 add_trampoline_func(m, ops, rec);
3465 ops = ftrace_find_tramp_ops_next(rec, ops);
3466 } while (ops);
3467 } else
3468 seq_puts(m, "\ttramp: ERROR!");
3469 } else {
3470 add_trampoline_func(m, NULL, rec);
3471 }
3472 }
3473
3474 seq_putc(m, '\n');
3475
3476 return 0;
3477}
3478
3479static const struct seq_operations show_ftrace_seq_ops = {
3480 .start = t_start,
3481 .next = t_next,
3482 .stop = t_stop,
3483 .show = t_show,
3484};
3485
3486static int
3487ftrace_avail_open(struct inode *inode, struct file *file)
3488{
3489 struct ftrace_iterator *iter;
3490 int ret;
3491
3492 ret = security_locked_down(LOCKDOWN_TRACEFS);
3493 if (ret)
3494 return ret;
3495
3496 if (unlikely(ftrace_disabled))
3497 return -ENODEV;
3498
3499 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3500 if (!iter)
3501 return -ENOMEM;
3502
3503 iter->pg = ftrace_pages_start;
3504 iter->ops = &global_ops;
3505
3506 return 0;
3507}
3508
3509static int
3510ftrace_enabled_open(struct inode *inode, struct file *file)
3511{
3512 struct ftrace_iterator *iter;
3513
3514 /*
3515 * This shows us what functions are currently being
3516 * traced and by what. Not sure if we want lockdown
3517 * to hide such critical information for an admin.
3518 * Although, perhaps it can show information we don't
3519 * want people to see, but if something is tracing
3520 * something, we probably want to know about it.
3521 */
3522
3523 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3524 if (!iter)
3525 return -ENOMEM;
3526
3527 iter->pg = ftrace_pages_start;
3528 iter->flags = FTRACE_ITER_ENABLED;
3529 iter->ops = &global_ops;
3530
3531 return 0;
3532}
3533
3534/**
3535 * ftrace_regex_open - initialize function tracer filter files
3536 * @ops: The ftrace_ops that hold the hash filters
3537 * @flag: The type of filter to process
3538 * @inode: The inode, usually passed in to your open routine
3539 * @file: The file, usually passed in to your open routine
3540 *
3541 * ftrace_regex_open() initializes the filter files for the
3542 * @ops. Depending on @flag it may process the filter hash or
3543 * the notrace hash of @ops. With this called from the open
3544 * routine, you can use ftrace_filter_write() for the write
3545 * routine if @flag has FTRACE_ITER_FILTER set, or
3546 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3547 * tracing_lseek() should be used as the lseek routine, and
3548 * release must call ftrace_regex_release().
3549 */
3550int
3551ftrace_regex_open(struct ftrace_ops *ops, int flag,
3552 struct inode *inode, struct file *file)
3553{
3554 struct ftrace_iterator *iter;
3555 struct ftrace_hash *hash;
3556 struct list_head *mod_head;
3557 struct trace_array *tr = ops->private;
3558 int ret = -ENOMEM;
3559
3560 ftrace_ops_init(ops);
3561
3562 if (unlikely(ftrace_disabled))
3563 return -ENODEV;
3564
3565 if (tracing_check_open_get_tr(tr))
3566 return -ENODEV;
3567
3568 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3569 if (!iter)
3570 goto out;
3571
3572 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX))
3573 goto out;
3574
3575 iter->ops = ops;
3576 iter->flags = flag;
3577 iter->tr = tr;
3578
3579 mutex_lock(&ops->func_hash->regex_lock);
3580
3581 if (flag & FTRACE_ITER_NOTRACE) {
3582 hash = ops->func_hash->notrace_hash;
3583 mod_head = tr ? &tr->mod_notrace : NULL;
3584 } else {
3585 hash = ops->func_hash->filter_hash;
3586 mod_head = tr ? &tr->mod_trace : NULL;
3587 }
3588
3589 iter->mod_list = mod_head;
3590
3591 if (file->f_mode & FMODE_WRITE) {
3592 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3593
3594 if (file->f_flags & O_TRUNC) {
3595 iter->hash = alloc_ftrace_hash(size_bits);
3596 clear_ftrace_mod_list(mod_head);
3597 } else {
3598 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3599 }
3600
3601 if (!iter->hash) {
3602 trace_parser_put(&iter->parser);
3603 goto out_unlock;
3604 }
3605 } else
3606 iter->hash = hash;
3607
3608 ret = 0;
3609
3610 if (file->f_mode & FMODE_READ) {
3611 iter->pg = ftrace_pages_start;
3612
3613 ret = seq_open(file, &show_ftrace_seq_ops);
3614 if (!ret) {
3615 struct seq_file *m = file->private_data;
3616 m->private = iter;
3617 } else {
3618 /* Failed */
3619 free_ftrace_hash(iter->hash);
3620 trace_parser_put(&iter->parser);
3621 }
3622 } else
3623 file->private_data = iter;
3624
3625 out_unlock:
3626 mutex_unlock(&ops->func_hash->regex_lock);
3627
3628 out:
3629 if (ret) {
3630 kfree(iter);
3631 if (tr)
3632 trace_array_put(tr);
3633 }
3634
3635 return ret;
3636}
3637
3638static int
3639ftrace_filter_open(struct inode *inode, struct file *file)
3640{
3641 struct ftrace_ops *ops = inode->i_private;
3642
3643 /* Checks for tracefs lockdown */
3644 return ftrace_regex_open(ops,
3645 FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
3646 inode, file);
3647}
3648
3649static int
3650ftrace_notrace_open(struct inode *inode, struct file *file)
3651{
3652 struct ftrace_ops *ops = inode->i_private;
3653
3654 /* Checks for tracefs lockdown */
3655 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3656 inode, file);
3657}
3658
3659/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3660struct ftrace_glob {
3661 char *search;
3662 unsigned len;
3663 int type;
3664};
3665
3666/*
3667 * If symbols in an architecture don't correspond exactly to the user-visible
3668 * name of what they represent, it is possible to define this function to
3669 * perform the necessary adjustments.
3670*/
3671char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3672{
3673 return str;
3674}
3675
3676static int ftrace_match(char *str, struct ftrace_glob *g)
3677{
3678 int matched = 0;
3679 int slen;
3680
3681 str = arch_ftrace_match_adjust(str, g->search);
3682
3683 switch (g->type) {
3684 case MATCH_FULL:
3685 if (strcmp(str, g->search) == 0)
3686 matched = 1;
3687 break;
3688 case MATCH_FRONT_ONLY:
3689 if (strncmp(str, g->search, g->len) == 0)
3690 matched = 1;
3691 break;
3692 case MATCH_MIDDLE_ONLY:
3693 if (strstr(str, g->search))
3694 matched = 1;
3695 break;
3696 case MATCH_END_ONLY:
3697 slen = strlen(str);
3698 if (slen >= g->len &&
3699 memcmp(str + slen - g->len, g->search, g->len) == 0)
3700 matched = 1;
3701 break;
3702 case MATCH_GLOB:
3703 if (glob_match(g->search, str))
3704 matched = 1;
3705 break;
3706 }
3707
3708 return matched;
3709}
3710
3711static int
3712enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3713{
3714 struct ftrace_func_entry *entry;
3715 int ret = 0;
3716
3717 entry = ftrace_lookup_ip(hash, rec->ip);
3718 if (clear_filter) {
3719 /* Do nothing if it doesn't exist */
3720 if (!entry)
3721 return 0;
3722
3723 free_hash_entry(hash, entry);
3724 } else {
3725 /* Do nothing if it exists */
3726 if (entry)
3727 return 0;
3728
3729 ret = add_hash_entry(hash, rec->ip);
3730 }
3731 return ret;
3732}
3733
3734static int
3735add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
3736 int clear_filter)
3737{
3738 long index = simple_strtoul(func_g->search, NULL, 0);
3739 struct ftrace_page *pg;
3740 struct dyn_ftrace *rec;
3741
3742 /* The index starts at 1 */
3743 if (--index < 0)
3744 return 0;
3745
3746 do_for_each_ftrace_rec(pg, rec) {
3747 if (pg->index <= index) {
3748 index -= pg->index;
3749 /* this is a double loop, break goes to the next page */
3750 break;
3751 }
3752 rec = &pg->records[index];
3753 enter_record(hash, rec, clear_filter);
3754 return 1;
3755 } while_for_each_ftrace_rec();
3756 return 0;
3757}
3758
3759static int
3760ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3761 struct ftrace_glob *mod_g, int exclude_mod)
3762{
3763 char str[KSYM_SYMBOL_LEN];
3764 char *modname;
3765
3766 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3767
3768 if (mod_g) {
3769 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3770
3771 /* blank module name to match all modules */
3772 if (!mod_g->len) {
3773 /* blank module globbing: modname xor exclude_mod */
3774 if (!exclude_mod != !modname)
3775 goto func_match;
3776 return 0;
3777 }
3778
3779 /*
3780 * exclude_mod is set to trace everything but the given
3781 * module. If it is set and the module matches, then
3782 * return 0. If it is not set, and the module doesn't match
3783 * also return 0. Otherwise, check the function to see if
3784 * that matches.
3785 */
3786 if (!mod_matches == !exclude_mod)
3787 return 0;
3788func_match:
3789 /* blank search means to match all funcs in the mod */
3790 if (!func_g->len)
3791 return 1;
3792 }
3793
3794 return ftrace_match(str, func_g);
3795}
3796
3797static int
3798match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3799{
3800 struct ftrace_page *pg;
3801 struct dyn_ftrace *rec;
3802 struct ftrace_glob func_g = { .type = MATCH_FULL };
3803 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3804 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3805 int exclude_mod = 0;
3806 int found = 0;
3807 int ret;
3808 int clear_filter = 0;
3809
3810 if (func) {
3811 func_g.type = filter_parse_regex(func, len, &func_g.search,
3812 &clear_filter);
3813 func_g.len = strlen(func_g.search);
3814 }
3815
3816 if (mod) {
3817 mod_g.type = filter_parse_regex(mod, strlen(mod),
3818 &mod_g.search, &exclude_mod);
3819 mod_g.len = strlen(mod_g.search);
3820 }
3821
3822 mutex_lock(&ftrace_lock);
3823
3824 if (unlikely(ftrace_disabled))
3825 goto out_unlock;
3826
3827 if (func_g.type == MATCH_INDEX) {
3828 found = add_rec_by_index(hash, &func_g, clear_filter);
3829 goto out_unlock;
3830 }
3831
3832 do_for_each_ftrace_rec(pg, rec) {
3833
3834 if (rec->flags & FTRACE_FL_DISABLED)
3835 continue;
3836
3837 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3838 ret = enter_record(hash, rec, clear_filter);
3839 if (ret < 0) {
3840 found = ret;
3841 goto out_unlock;
3842 }
3843 found = 1;
3844 }
3845 } while_for_each_ftrace_rec();
3846 out_unlock:
3847 mutex_unlock(&ftrace_lock);
3848
3849 return found;
3850}
3851
3852static int
3853ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3854{
3855 return match_records(hash, buff, len, NULL);
3856}
3857
3858static void ftrace_ops_update_code(struct ftrace_ops *ops,
3859 struct ftrace_ops_hash *old_hash)
3860{
3861 struct ftrace_ops *op;
3862
3863 if (!ftrace_enabled)
3864 return;
3865
3866 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
3867 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
3868 return;
3869 }
3870
3871 /*
3872 * If this is the shared global_ops filter, then we need to
3873 * check if there is another ops that shares it, is enabled.
3874 * If so, we still need to run the modify code.
3875 */
3876 if (ops->func_hash != &global_ops.local_hash)
3877 return;
3878
3879 do_for_each_ftrace_op(op, ftrace_ops_list) {
3880 if (op->func_hash == &global_ops.local_hash &&
3881 op->flags & FTRACE_OPS_FL_ENABLED) {
3882 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
3883 /* Only need to do this once */
3884 return;
3885 }
3886 } while_for_each_ftrace_op(op);
3887}
3888
3889static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3890 struct ftrace_hash **orig_hash,
3891 struct ftrace_hash *hash,
3892 int enable)
3893{
3894 struct ftrace_ops_hash old_hash_ops;
3895 struct ftrace_hash *old_hash;
3896 int ret;
3897
3898 old_hash = *orig_hash;
3899 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3900 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3901 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3902 if (!ret) {
3903 ftrace_ops_update_code(ops, &old_hash_ops);
3904 free_ftrace_hash_rcu(old_hash);
3905 }
3906 return ret;
3907}
3908
3909static bool module_exists(const char *module)
3910{
3911 /* All modules have the symbol __this_module */
3912 static const char this_mod[] = "__this_module";
3913 char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
3914 unsigned long val;
3915 int n;
3916
3917 n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod);
3918
3919 if (n > sizeof(modname) - 1)
3920 return false;
3921
3922 val = module_kallsyms_lookup_name(modname);
3923 return val != 0;
3924}
3925
3926static int cache_mod(struct trace_array *tr,
3927 const char *func, char *module, int enable)
3928{
3929 struct ftrace_mod_load *ftrace_mod, *n;
3930 struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
3931 int ret;
3932
3933 mutex_lock(&ftrace_lock);
3934
3935 /* We do not cache inverse filters */
3936 if (func[0] == '!') {
3937 func++;
3938 ret = -EINVAL;
3939
3940 /* Look to remove this hash */
3941 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3942 if (strcmp(ftrace_mod->module, module) != 0)
3943 continue;
3944
3945 /* no func matches all */
3946 if (strcmp(func, "*") == 0 ||
3947 (ftrace_mod->func &&
3948 strcmp(ftrace_mod->func, func) == 0)) {
3949 ret = 0;
3950 free_ftrace_mod(ftrace_mod);
3951 continue;
3952 }
3953 }
3954 goto out;
3955 }
3956
3957 ret = -EINVAL;
3958 /* We only care about modules that have not been loaded yet */
3959 if (module_exists(module))
3960 goto out;
3961
3962 /* Save this string off, and execute it when the module is loaded */
3963 ret = ftrace_add_mod(tr, func, module, enable);
3964 out:
3965 mutex_unlock(&ftrace_lock);
3966
3967 return ret;
3968}
3969
3970static int
3971ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3972 int reset, int enable);
3973
3974#ifdef CONFIG_MODULES
3975static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
3976 char *mod, bool enable)
3977{
3978 struct ftrace_mod_load *ftrace_mod, *n;
3979 struct ftrace_hash **orig_hash, *new_hash;
3980 LIST_HEAD(process_mods);
3981 char *func;
3982 int ret;
3983
3984 mutex_lock(&ops->func_hash->regex_lock);
3985
3986 if (enable)
3987 orig_hash = &ops->func_hash->filter_hash;
3988 else
3989 orig_hash = &ops->func_hash->notrace_hash;
3990
3991 new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
3992 *orig_hash);
3993 if (!new_hash)
3994 goto out; /* warn? */
3995
3996 mutex_lock(&ftrace_lock);
3997
3998 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3999
4000 if (strcmp(ftrace_mod->module, mod) != 0)
4001 continue;
4002
4003 if (ftrace_mod->func)
4004 func = kstrdup(ftrace_mod->func, GFP_KERNEL);
4005 else
4006 func = kstrdup("*", GFP_KERNEL);
4007
4008 if (!func) /* warn? */
4009 continue;
4010
4011 list_del(&ftrace_mod->list);
4012 list_add(&ftrace_mod->list, &process_mods);
4013
4014 /* Use the newly allocated func, as it may be "*" */
4015 kfree(ftrace_mod->func);
4016 ftrace_mod->func = func;
4017 }
4018
4019 mutex_unlock(&ftrace_lock);
4020
4021 list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
4022
4023 func = ftrace_mod->func;
4024
4025 /* Grabs ftrace_lock, which is why we have this extra step */
4026 match_records(new_hash, func, strlen(func), mod);
4027 free_ftrace_mod(ftrace_mod);
4028 }
4029
4030 if (enable && list_empty(head))
4031 new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4032
4033 mutex_lock(&ftrace_lock);
4034
4035 ret = ftrace_hash_move_and_update_ops(ops, orig_hash,
4036 new_hash, enable);
4037 mutex_unlock(&ftrace_lock);
4038
4039 out:
4040 mutex_unlock(&ops->func_hash->regex_lock);
4041
4042 free_ftrace_hash(new_hash);
4043}
4044
4045static void process_cached_mods(const char *mod_name)
4046{
4047 struct trace_array *tr;
4048 char *mod;
4049
4050 mod = kstrdup(mod_name, GFP_KERNEL);
4051 if (!mod)
4052 return;
4053
4054 mutex_lock(&trace_types_lock);
4055 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4056 if (!list_empty(&tr->mod_trace))
4057 process_mod_list(&tr->mod_trace, tr->ops, mod, true);
4058 if (!list_empty(&tr->mod_notrace))
4059 process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
4060 }
4061 mutex_unlock(&trace_types_lock);
4062
4063 kfree(mod);
4064}
4065#endif
4066
4067/*
4068 * We register the module command as a template to show others how
4069 * to register the a command as well.
4070 */
4071
4072static int
4073ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4074 char *func_orig, char *cmd, char *module, int enable)
4075{
4076 char *func;
4077 int ret;
4078
4079 /* match_records() modifies func, and we need the original */
4080 func = kstrdup(func_orig, GFP_KERNEL);
4081 if (!func)
4082 return -ENOMEM;
4083
4084 /*
4085 * cmd == 'mod' because we only registered this func
4086 * for the 'mod' ftrace_func_command.
4087 * But if you register one func with multiple commands,
4088 * you can tell which command was used by the cmd
4089 * parameter.
4090 */
4091 ret = match_records(hash, func, strlen(func), module);
4092 kfree(func);
4093
4094 if (!ret)
4095 return cache_mod(tr, func_orig, module, enable);
4096 if (ret < 0)
4097 return ret;
4098 return 0;
4099}
4100
4101static struct ftrace_func_command ftrace_mod_cmd = {
4102 .name = "mod",
4103 .func = ftrace_mod_callback,
4104};
4105
4106static int __init ftrace_mod_cmd_init(void)
4107{
4108 return register_ftrace_command(&ftrace_mod_cmd);
4109}
4110core_initcall(ftrace_mod_cmd_init);
4111
4112static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4113 struct ftrace_ops *op, struct pt_regs *pt_regs)
4114{
4115 struct ftrace_probe_ops *probe_ops;
4116 struct ftrace_func_probe *probe;
4117
4118 probe = container_of(op, struct ftrace_func_probe, ops);
4119 probe_ops = probe->probe_ops;
4120
4121 /*
4122 * Disable preemption for these calls to prevent a RCU grace
4123 * period. This syncs the hash iteration and freeing of items
4124 * on the hash. rcu_read_lock is too dangerous here.
4125 */
4126 preempt_disable_notrace();
4127 probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4128 preempt_enable_notrace();
4129}
4130
4131struct ftrace_func_map {
4132 struct ftrace_func_entry entry;
4133 void *data;
4134};
4135
4136struct ftrace_func_mapper {
4137 struct ftrace_hash hash;
4138};
4139
4140/**
4141 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4142 *
4143 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4144 */
4145struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4146{
4147 struct ftrace_hash *hash;
4148
4149 /*
4150 * The mapper is simply a ftrace_hash, but since the entries
4151 * in the hash are not ftrace_func_entry type, we define it
4152 * as a separate structure.
4153 */
4154 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4155 return (struct ftrace_func_mapper *)hash;
4156}
4157
4158/**
4159 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4160 * @mapper: The mapper that has the ip maps
4161 * @ip: the instruction pointer to find the data for
4162 *
4163 * Returns the data mapped to @ip if found otherwise NULL. The return
4164 * is actually the address of the mapper data pointer. The address is
4165 * returned for use cases where the data is no bigger than a long, and
4166 * the user can use the data pointer as its data instead of having to
4167 * allocate more memory for the reference.
4168 */
4169void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4170 unsigned long ip)
4171{
4172 struct ftrace_func_entry *entry;
4173 struct ftrace_func_map *map;
4174
4175 entry = ftrace_lookup_ip(&mapper->hash, ip);
4176 if (!entry)
4177 return NULL;
4178
4179 map = (struct ftrace_func_map *)entry;
4180 return &map->data;
4181}
4182
4183/**
4184 * ftrace_func_mapper_add_ip - Map some data to an ip
4185 * @mapper: The mapper that has the ip maps
4186 * @ip: The instruction pointer address to map @data to
4187 * @data: The data to map to @ip
4188 *
4189 * Returns 0 on succes otherwise an error.
4190 */
4191int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4192 unsigned long ip, void *data)
4193{
4194 struct ftrace_func_entry *entry;
4195 struct ftrace_func_map *map;
4196
4197 entry = ftrace_lookup_ip(&mapper->hash, ip);
4198 if (entry)
4199 return -EBUSY;
4200
4201 map = kmalloc(sizeof(*map), GFP_KERNEL);
4202 if (!map)
4203 return -ENOMEM;
4204
4205 map->entry.ip = ip;
4206 map->data = data;
4207
4208 __add_hash_entry(&mapper->hash, &map->entry);
4209
4210 return 0;
4211}
4212
4213/**
4214 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4215 * @mapper: The mapper that has the ip maps
4216 * @ip: The instruction pointer address to remove the data from
4217 *
4218 * Returns the data if it is found, otherwise NULL.
4219 * Note, if the data pointer is used as the data itself, (see
4220 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4221 * if the data pointer was set to zero.
4222 */
4223void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4224 unsigned long ip)
4225{
4226 struct ftrace_func_entry *entry;
4227 struct ftrace_func_map *map;
4228 void *data;
4229
4230 entry = ftrace_lookup_ip(&mapper->hash, ip);
4231 if (!entry)
4232 return NULL;
4233
4234 map = (struct ftrace_func_map *)entry;
4235 data = map->data;
4236
4237 remove_hash_entry(&mapper->hash, entry);
4238 kfree(entry);
4239
4240 return data;
4241}
4242
4243/**
4244 * free_ftrace_func_mapper - free a mapping of ips and data
4245 * @mapper: The mapper that has the ip maps
4246 * @free_func: A function to be called on each data item.
4247 *
4248 * This is used to free the function mapper. The @free_func is optional
4249 * and can be used if the data needs to be freed as well.
4250 */
4251void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4252 ftrace_mapper_func free_func)
4253{
4254 struct ftrace_func_entry *entry;
4255 struct ftrace_func_map *map;
4256 struct hlist_head *hhd;
4257 int size, i;
4258
4259 if (!mapper)
4260 return;
4261
4262 if (free_func && mapper->hash.count) {
4263 size = 1 << mapper->hash.size_bits;
4264 for (i = 0; i < size; i++) {
4265 hhd = &mapper->hash.buckets[i];
4266 hlist_for_each_entry(entry, hhd, hlist) {
4267 map = (struct ftrace_func_map *)entry;
4268 free_func(map);
4269 }
4270 }
4271 }
4272 free_ftrace_hash(&mapper->hash);
4273}
4274
4275static void release_probe(struct ftrace_func_probe *probe)
4276{
4277 struct ftrace_probe_ops *probe_ops;
4278
4279 mutex_lock(&ftrace_lock);
4280
4281 WARN_ON(probe->ref <= 0);
4282
4283 /* Subtract the ref that was used to protect this instance */
4284 probe->ref--;
4285
4286 if (!probe->ref) {
4287 probe_ops = probe->probe_ops;
4288 /*
4289 * Sending zero as ip tells probe_ops to free
4290 * the probe->data itself
4291 */
4292 if (probe_ops->free)
4293 probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4294 list_del(&probe->list);
4295 kfree(probe);
4296 }
4297 mutex_unlock(&ftrace_lock);
4298}
4299
4300static void acquire_probe_locked(struct ftrace_func_probe *probe)
4301{
4302 /*
4303 * Add one ref to keep it from being freed when releasing the
4304 * ftrace_lock mutex.
4305 */
4306 probe->ref++;
4307}
4308
4309int
4310register_ftrace_function_probe(char *glob, struct trace_array *tr,
4311 struct ftrace_probe_ops *probe_ops,
4312 void *data)
4313{
4314 struct ftrace_func_entry *entry;
4315 struct ftrace_func_probe *probe;
4316 struct ftrace_hash **orig_hash;
4317 struct ftrace_hash *old_hash;
4318 struct ftrace_hash *hash;
4319 int count = 0;
4320 int size;
4321 int ret;
4322 int i;
4323
4324 if (WARN_ON(!tr))
4325 return -EINVAL;
4326
4327 /* We do not support '!' for function probes */
4328 if (WARN_ON(glob[0] == '!'))
4329 return -EINVAL;
4330
4331
4332 mutex_lock(&ftrace_lock);
4333 /* Check if the probe_ops is already registered */
4334 list_for_each_entry(probe, &tr->func_probes, list) {
4335 if (probe->probe_ops == probe_ops)
4336 break;
4337 }
4338 if (&probe->list == &tr->func_probes) {
4339 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4340 if (!probe) {
4341 mutex_unlock(&ftrace_lock);
4342 return -ENOMEM;
4343 }
4344 probe->probe_ops = probe_ops;
4345 probe->ops.func = function_trace_probe_call;
4346 probe->tr = tr;
4347 ftrace_ops_init(&probe->ops);
4348 list_add(&probe->list, &tr->func_probes);
4349 }
4350
4351 acquire_probe_locked(probe);
4352
4353 mutex_unlock(&ftrace_lock);
4354
4355 /*
4356 * Note, there's a small window here that the func_hash->filter_hash
4357 * may be NULL or empty. Need to be carefule when reading the loop.
4358 */
4359 mutex_lock(&probe->ops.func_hash->regex_lock);
4360
4361 orig_hash = &probe->ops.func_hash->filter_hash;
4362 old_hash = *orig_hash;
4363 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4364
4365 if (!hash) {
4366 ret = -ENOMEM;
4367 goto out;
4368 }
4369
4370 ret = ftrace_match_records(hash, glob, strlen(glob));
4371
4372 /* Nothing found? */
4373 if (!ret)
4374 ret = -EINVAL;
4375
4376 if (ret < 0)
4377 goto out;
4378
4379 size = 1 << hash->size_bits;
4380 for (i = 0; i < size; i++) {
4381 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4382 if (ftrace_lookup_ip(old_hash, entry->ip))
4383 continue;
4384 /*
4385 * The caller might want to do something special
4386 * for each function we find. We call the callback
4387 * to give the caller an opportunity to do so.
4388 */
4389 if (probe_ops->init) {
4390 ret = probe_ops->init(probe_ops, tr,
4391 entry->ip, data,
4392 &probe->data);
4393 if (ret < 0) {
4394 if (probe_ops->free && count)
4395 probe_ops->free(probe_ops, tr,
4396 0, probe->data);
4397 probe->data = NULL;
4398 goto out;
4399 }
4400 }
4401 count++;
4402 }
4403 }
4404
4405 mutex_lock(&ftrace_lock);
4406
4407 if (!count) {
4408 /* Nothing was added? */
4409 ret = -EINVAL;
4410 goto out_unlock;
4411 }
4412
4413 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4414 hash, 1);
4415 if (ret < 0)
4416 goto err_unlock;
4417
4418 /* One ref for each new function traced */
4419 probe->ref += count;
4420
4421 if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4422 ret = ftrace_startup(&probe->ops, 0);
4423
4424 out_unlock:
4425 mutex_unlock(&ftrace_lock);
4426
4427 if (!ret)
4428 ret = count;
4429 out:
4430 mutex_unlock(&probe->ops.func_hash->regex_lock);
4431 free_ftrace_hash(hash);
4432
4433 release_probe(probe);
4434
4435 return ret;
4436
4437 err_unlock:
4438 if (!probe_ops->free || !count)
4439 goto out_unlock;
4440
4441 /* Failed to do the move, need to call the free functions */
4442 for (i = 0; i < size; i++) {
4443 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4444 if (ftrace_lookup_ip(old_hash, entry->ip))
4445 continue;
4446 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4447 }
4448 }
4449 goto out_unlock;
4450}
4451
4452int
4453unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4454 struct ftrace_probe_ops *probe_ops)
4455{
4456 struct ftrace_ops_hash old_hash_ops;
4457 struct ftrace_func_entry *entry;
4458 struct ftrace_func_probe *probe;
4459 struct ftrace_glob func_g;
4460 struct ftrace_hash **orig_hash;
4461 struct ftrace_hash *old_hash;
4462 struct ftrace_hash *hash = NULL;
4463 struct hlist_node *tmp;
4464 struct hlist_head hhd;
4465 char str[KSYM_SYMBOL_LEN];
4466 int count = 0;
4467 int i, ret = -ENODEV;
4468 int size;
4469
4470 if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4471 func_g.search = NULL;
4472 else {
4473 int not;
4474
4475 func_g.type = filter_parse_regex(glob, strlen(glob),
4476 &func_g.search, ¬);
4477 func_g.len = strlen(func_g.search);
4478
4479 /* we do not support '!' for function probes */
4480 if (WARN_ON(not))
4481 return -EINVAL;
4482 }
4483
4484 mutex_lock(&ftrace_lock);
4485 /* Check if the probe_ops is already registered */
4486 list_for_each_entry(probe, &tr->func_probes, list) {
4487 if (probe->probe_ops == probe_ops)
4488 break;
4489 }
4490 if (&probe->list == &tr->func_probes)
4491 goto err_unlock_ftrace;
4492
4493 ret = -EINVAL;
4494 if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4495 goto err_unlock_ftrace;
4496
4497 acquire_probe_locked(probe);
4498
4499 mutex_unlock(&ftrace_lock);
4500
4501 mutex_lock(&probe->ops.func_hash->regex_lock);
4502
4503 orig_hash = &probe->ops.func_hash->filter_hash;
4504 old_hash = *orig_hash;
4505
4506 if (ftrace_hash_empty(old_hash))
4507 goto out_unlock;
4508
4509 old_hash_ops.filter_hash = old_hash;
4510 /* Probes only have filters */
4511 old_hash_ops.notrace_hash = NULL;
4512
4513 ret = -ENOMEM;
4514 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4515 if (!hash)
4516 goto out_unlock;
4517
4518 INIT_HLIST_HEAD(&hhd);
4519
4520 size = 1 << hash->size_bits;
4521 for (i = 0; i < size; i++) {
4522 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4523
4524 if (func_g.search) {
4525 kallsyms_lookup(entry->ip, NULL, NULL,
4526 NULL, str);
4527 if (!ftrace_match(str, &func_g))
4528 continue;
4529 }
4530 count++;
4531 remove_hash_entry(hash, entry);
4532 hlist_add_head(&entry->hlist, &hhd);
4533 }
4534 }
4535
4536 /* Nothing found? */
4537 if (!count) {
4538 ret = -EINVAL;
4539 goto out_unlock;
4540 }
4541
4542 mutex_lock(&ftrace_lock);
4543
4544 WARN_ON(probe->ref < count);
4545
4546 probe->ref -= count;
4547
4548 if (ftrace_hash_empty(hash))
4549 ftrace_shutdown(&probe->ops, 0);
4550
4551 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4552 hash, 1);
4553
4554 /* still need to update the function call sites */
4555 if (ftrace_enabled && !ftrace_hash_empty(hash))
4556 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
4557 &old_hash_ops);
4558 synchronize_rcu();
4559
4560 hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
4561 hlist_del(&entry->hlist);
4562 if (probe_ops->free)
4563 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4564 kfree(entry);
4565 }
4566 mutex_unlock(&ftrace_lock);
4567
4568 out_unlock:
4569 mutex_unlock(&probe->ops.func_hash->regex_lock);
4570 free_ftrace_hash(hash);
4571
4572 release_probe(probe);
4573
4574 return ret;
4575
4576 err_unlock_ftrace:
4577 mutex_unlock(&ftrace_lock);
4578 return ret;
4579}
4580
4581void clear_ftrace_function_probes(struct trace_array *tr)
4582{
4583 struct ftrace_func_probe *probe, *n;
4584
4585 list_for_each_entry_safe(probe, n, &tr->func_probes, list)
4586 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
4587}
4588
4589static LIST_HEAD(ftrace_commands);
4590static DEFINE_MUTEX(ftrace_cmd_mutex);
4591
4592/*
4593 * Currently we only register ftrace commands from __init, so mark this
4594 * __init too.
4595 */
4596__init int register_ftrace_command(struct ftrace_func_command *cmd)
4597{
4598 struct ftrace_func_command *p;
4599 int ret = 0;
4600
4601 mutex_lock(&ftrace_cmd_mutex);
4602 list_for_each_entry(p, &ftrace_commands, list) {
4603 if (strcmp(cmd->name, p->name) == 0) {
4604 ret = -EBUSY;
4605 goto out_unlock;
4606 }
4607 }
4608 list_add(&cmd->list, &ftrace_commands);
4609 out_unlock:
4610 mutex_unlock(&ftrace_cmd_mutex);
4611
4612 return ret;
4613}
4614
4615/*
4616 * Currently we only unregister ftrace commands from __init, so mark
4617 * this __init too.
4618 */
4619__init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4620{
4621 struct ftrace_func_command *p, *n;
4622 int ret = -ENODEV;
4623
4624 mutex_lock(&ftrace_cmd_mutex);
4625 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4626 if (strcmp(cmd->name, p->name) == 0) {
4627 ret = 0;
4628 list_del_init(&p->list);
4629 goto out_unlock;
4630 }
4631 }
4632 out_unlock:
4633 mutex_unlock(&ftrace_cmd_mutex);
4634
4635 return ret;
4636}
4637
4638static int ftrace_process_regex(struct ftrace_iterator *iter,
4639 char *buff, int len, int enable)
4640{
4641 struct ftrace_hash *hash = iter->hash;
4642 struct trace_array *tr = iter->ops->private;
4643 char *func, *command, *next = buff;
4644 struct ftrace_func_command *p;
4645 int ret = -EINVAL;
4646
4647 func = strsep(&next, ":");
4648
4649 if (!next) {
4650 ret = ftrace_match_records(hash, func, len);
4651 if (!ret)
4652 ret = -EINVAL;
4653 if (ret < 0)
4654 return ret;
4655 return 0;
4656 }
4657
4658 /* command found */
4659
4660 command = strsep(&next, ":");
4661
4662 mutex_lock(&ftrace_cmd_mutex);
4663 list_for_each_entry(p, &ftrace_commands, list) {
4664 if (strcmp(p->name, command) == 0) {
4665 ret = p->func(tr, hash, func, command, next, enable);
4666 goto out_unlock;
4667 }
4668 }
4669 out_unlock:
4670 mutex_unlock(&ftrace_cmd_mutex);
4671
4672 return ret;
4673}
4674
4675static ssize_t
4676ftrace_regex_write(struct file *file, const char __user *ubuf,
4677 size_t cnt, loff_t *ppos, int enable)
4678{
4679 struct ftrace_iterator *iter;
4680 struct trace_parser *parser;
4681 ssize_t ret, read;
4682
4683 if (!cnt)
4684 return 0;
4685
4686 if (file->f_mode & FMODE_READ) {
4687 struct seq_file *m = file->private_data;
4688 iter = m->private;
4689 } else
4690 iter = file->private_data;
4691
4692 if (unlikely(ftrace_disabled))
4693 return -ENODEV;
4694
4695 /* iter->hash is a local copy, so we don't need regex_lock */
4696
4697 parser = &iter->parser;
4698 read = trace_get_user(parser, ubuf, cnt, ppos);
4699
4700 if (read >= 0 && trace_parser_loaded(parser) &&
4701 !trace_parser_cont(parser)) {
4702 ret = ftrace_process_regex(iter, parser->buffer,
4703 parser->idx, enable);
4704 trace_parser_clear(parser);
4705 if (ret < 0)
4706 goto out;
4707 }
4708
4709 ret = read;
4710 out:
4711 return ret;
4712}
4713
4714ssize_t
4715ftrace_filter_write(struct file *file, const char __user *ubuf,
4716 size_t cnt, loff_t *ppos)
4717{
4718 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4719}
4720
4721ssize_t
4722ftrace_notrace_write(struct file *file, const char __user *ubuf,
4723 size_t cnt, loff_t *ppos)
4724{
4725 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4726}
4727
4728static int
4729ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4730{
4731 struct ftrace_func_entry *entry;
4732
4733 if (!ftrace_location(ip))
4734 return -EINVAL;
4735
4736 if (remove) {
4737 entry = ftrace_lookup_ip(hash, ip);
4738 if (!entry)
4739 return -ENOENT;
4740 free_hash_entry(hash, entry);
4741 return 0;
4742 }
4743
4744 return add_hash_entry(hash, ip);
4745}
4746
4747static int
4748ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4749 unsigned long ip, int remove, int reset, int enable)
4750{
4751 struct ftrace_hash **orig_hash;
4752 struct ftrace_hash *hash;
4753 int ret;
4754
4755 if (unlikely(ftrace_disabled))
4756 return -ENODEV;
4757
4758 mutex_lock(&ops->func_hash->regex_lock);
4759
4760 if (enable)
4761 orig_hash = &ops->func_hash->filter_hash;
4762 else
4763 orig_hash = &ops->func_hash->notrace_hash;
4764
4765 if (reset)
4766 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4767 else
4768 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4769
4770 if (!hash) {
4771 ret = -ENOMEM;
4772 goto out_regex_unlock;
4773 }
4774
4775 if (buf && !ftrace_match_records(hash, buf, len)) {
4776 ret = -EINVAL;
4777 goto out_regex_unlock;
4778 }
4779 if (ip) {
4780 ret = ftrace_match_addr(hash, ip, remove);
4781 if (ret < 0)
4782 goto out_regex_unlock;
4783 }
4784
4785 mutex_lock(&ftrace_lock);
4786 ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
4787 mutex_unlock(&ftrace_lock);
4788
4789 out_regex_unlock:
4790 mutex_unlock(&ops->func_hash->regex_lock);
4791
4792 free_ftrace_hash(hash);
4793 return ret;
4794}
4795
4796static int
4797ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4798 int reset, int enable)
4799{
4800 return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable);
4801}
4802
4803/**
4804 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4805 * @ops - the ops to set the filter with
4806 * @ip - the address to add to or remove from the filter.
4807 * @remove - non zero to remove the ip from the filter
4808 * @reset - non zero to reset all filters before applying this filter.
4809 *
4810 * Filters denote which functions should be enabled when tracing is enabled
4811 * If @ip is NULL, it failes to update filter.
4812 */
4813int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4814 int remove, int reset)
4815{
4816 ftrace_ops_init(ops);
4817 return ftrace_set_addr(ops, ip, remove, reset, 1);
4818}
4819EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4820
4821/**
4822 * ftrace_ops_set_global_filter - setup ops to use global filters
4823 * @ops - the ops which will use the global filters
4824 *
4825 * ftrace users who need global function trace filtering should call this.
4826 * It can set the global filter only if ops were not initialized before.
4827 */
4828void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4829{
4830 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4831 return;
4832
4833 ftrace_ops_init(ops);
4834 ops->func_hash = &global_ops.local_hash;
4835}
4836EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4837
4838static int
4839ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4840 int reset, int enable)
4841{
4842 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4843}
4844
4845/**
4846 * ftrace_set_filter - set a function to filter on in ftrace
4847 * @ops - the ops to set the filter with
4848 * @buf - the string that holds the function filter text.
4849 * @len - the length of the string.
4850 * @reset - non zero to reset all filters before applying this filter.
4851 *
4852 * Filters denote which functions should be enabled when tracing is enabled.
4853 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4854 */
4855int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4856 int len, int reset)
4857{
4858 ftrace_ops_init(ops);
4859 return ftrace_set_regex(ops, buf, len, reset, 1);
4860}
4861EXPORT_SYMBOL_GPL(ftrace_set_filter);
4862
4863/**
4864 * ftrace_set_notrace - set a function to not trace in ftrace
4865 * @ops - the ops to set the notrace filter with
4866 * @buf - the string that holds the function notrace text.
4867 * @len - the length of the string.
4868 * @reset - non zero to reset all filters before applying this filter.
4869 *
4870 * Notrace Filters denote which functions should not be enabled when tracing
4871 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4872 * for tracing.
4873 */
4874int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4875 int len, int reset)
4876{
4877 ftrace_ops_init(ops);
4878 return ftrace_set_regex(ops, buf, len, reset, 0);
4879}
4880EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4881/**
4882 * ftrace_set_global_filter - set a function to filter on with global tracers
4883 * @buf - the string that holds the function filter text.
4884 * @len - the length of the string.
4885 * @reset - non zero to reset all filters before applying this filter.
4886 *
4887 * Filters denote which functions should be enabled when tracing is enabled.
4888 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4889 */
4890void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4891{
4892 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4893}
4894EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4895
4896/**
4897 * ftrace_set_global_notrace - set a function to not trace with global tracers
4898 * @buf - the string that holds the function notrace text.
4899 * @len - the length of the string.
4900 * @reset - non zero to reset all filters before applying this filter.
4901 *
4902 * Notrace Filters denote which functions should not be enabled when tracing
4903 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4904 * for tracing.
4905 */
4906void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4907{
4908 ftrace_set_regex(&global_ops, buf, len, reset, 0);
4909}
4910EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4911
4912/*
4913 * command line interface to allow users to set filters on boot up.
4914 */
4915#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4916static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4917static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4918
4919/* Used by function selftest to not test if filter is set */
4920bool ftrace_filter_param __initdata;
4921
4922static int __init set_ftrace_notrace(char *str)
4923{
4924 ftrace_filter_param = true;
4925 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4926 return 1;
4927}
4928__setup("ftrace_notrace=", set_ftrace_notrace);
4929
4930static int __init set_ftrace_filter(char *str)
4931{
4932 ftrace_filter_param = true;
4933 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4934 return 1;
4935}
4936__setup("ftrace_filter=", set_ftrace_filter);
4937
4938#ifdef CONFIG_FUNCTION_GRAPH_TRACER
4939static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4940static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4941static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
4942
4943static int __init set_graph_function(char *str)
4944{
4945 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4946 return 1;
4947}
4948__setup("ftrace_graph_filter=", set_graph_function);
4949
4950static int __init set_graph_notrace_function(char *str)
4951{
4952 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4953 return 1;
4954}
4955__setup("ftrace_graph_notrace=", set_graph_notrace_function);
4956
4957static int __init set_graph_max_depth_function(char *str)
4958{
4959 if (!str)
4960 return 0;
4961 fgraph_max_depth = simple_strtoul(str, NULL, 0);
4962 return 1;
4963}
4964__setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
4965
4966static void __init set_ftrace_early_graph(char *buf, int enable)
4967{
4968 int ret;
4969 char *func;
4970 struct ftrace_hash *hash;
4971
4972 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4973 if (WARN_ON(!hash))
4974 return;
4975
4976 while (buf) {
4977 func = strsep(&buf, ",");
4978 /* we allow only one expression at a time */
4979 ret = ftrace_graph_set_hash(hash, func);
4980 if (ret)
4981 printk(KERN_DEBUG "ftrace: function %s not "
4982 "traceable\n", func);
4983 }
4984
4985 if (enable)
4986 ftrace_graph_hash = hash;
4987 else
4988 ftrace_graph_notrace_hash = hash;
4989}
4990#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4991
4992void __init
4993ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4994{
4995 char *func;
4996
4997 ftrace_ops_init(ops);
4998
4999 while (buf) {
5000 func = strsep(&buf, ",");
5001 ftrace_set_regex(ops, func, strlen(func), 0, enable);
5002 }
5003}
5004
5005static void __init set_ftrace_early_filters(void)
5006{
5007 if (ftrace_filter_buf[0])
5008 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
5009 if (ftrace_notrace_buf[0])
5010 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
5011#ifdef CONFIG_FUNCTION_GRAPH_TRACER
5012 if (ftrace_graph_buf[0])
5013 set_ftrace_early_graph(ftrace_graph_buf, 1);
5014 if (ftrace_graph_notrace_buf[0])
5015 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
5016#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5017}
5018
5019int ftrace_regex_release(struct inode *inode, struct file *file)
5020{
5021 struct seq_file *m = (struct seq_file *)file->private_data;
5022 struct ftrace_iterator *iter;
5023 struct ftrace_hash **orig_hash;
5024 struct trace_parser *parser;
5025 int filter_hash;
5026 int ret;
5027
5028 if (file->f_mode & FMODE_READ) {
5029 iter = m->private;
5030 seq_release(inode, file);
5031 } else
5032 iter = file->private_data;
5033
5034 parser = &iter->parser;
5035 if (trace_parser_loaded(parser)) {
5036 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
5037 }
5038
5039 trace_parser_put(parser);
5040
5041 mutex_lock(&iter->ops->func_hash->regex_lock);
5042
5043 if (file->f_mode & FMODE_WRITE) {
5044 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5045
5046 if (filter_hash) {
5047 orig_hash = &iter->ops->func_hash->filter_hash;
5048 if (iter->tr && !list_empty(&iter->tr->mod_trace))
5049 iter->hash->flags |= FTRACE_HASH_FL_MOD;
5050 } else
5051 orig_hash = &iter->ops->func_hash->notrace_hash;
5052
5053 mutex_lock(&ftrace_lock);
5054 ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
5055 iter->hash, filter_hash);
5056 mutex_unlock(&ftrace_lock);
5057 } else {
5058 /* For read only, the hash is the ops hash */
5059 iter->hash = NULL;
5060 }
5061
5062 mutex_unlock(&iter->ops->func_hash->regex_lock);
5063 free_ftrace_hash(iter->hash);
5064 if (iter->tr)
5065 trace_array_put(iter->tr);
5066 kfree(iter);
5067
5068 return 0;
5069}
5070
5071static const struct file_operations ftrace_avail_fops = {
5072 .open = ftrace_avail_open,
5073 .read = seq_read,
5074 .llseek = seq_lseek,
5075 .release = seq_release_private,
5076};
5077
5078static const struct file_operations ftrace_enabled_fops = {
5079 .open = ftrace_enabled_open,
5080 .read = seq_read,
5081 .llseek = seq_lseek,
5082 .release = seq_release_private,
5083};
5084
5085static const struct file_operations ftrace_filter_fops = {
5086 .open = ftrace_filter_open,
5087 .read = seq_read,
5088 .write = ftrace_filter_write,
5089 .llseek = tracing_lseek,
5090 .release = ftrace_regex_release,
5091};
5092
5093static const struct file_operations ftrace_notrace_fops = {
5094 .open = ftrace_notrace_open,
5095 .read = seq_read,
5096 .write = ftrace_notrace_write,
5097 .llseek = tracing_lseek,
5098 .release = ftrace_regex_release,
5099};
5100
5101#ifdef CONFIG_FUNCTION_GRAPH_TRACER
5102
5103static DEFINE_MUTEX(graph_lock);
5104
5105struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
5106struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
5107
5108enum graph_filter_type {
5109 GRAPH_FILTER_NOTRACE = 0,
5110 GRAPH_FILTER_FUNCTION,
5111};
5112
5113#define FTRACE_GRAPH_EMPTY ((void *)1)
5114
5115struct ftrace_graph_data {
5116 struct ftrace_hash *hash;
5117 struct ftrace_func_entry *entry;
5118 int idx; /* for hash table iteration */
5119 enum graph_filter_type type;
5120 struct ftrace_hash *new_hash;
5121 const struct seq_operations *seq_ops;
5122 struct trace_parser parser;
5123};
5124
5125static void *
5126__g_next(struct seq_file *m, loff_t *pos)
5127{
5128 struct ftrace_graph_data *fgd = m->private;
5129 struct ftrace_func_entry *entry = fgd->entry;
5130 struct hlist_head *head;
5131 int i, idx = fgd->idx;
5132
5133 if (*pos >= fgd->hash->count)
5134 return NULL;
5135
5136 if (entry) {
5137 hlist_for_each_entry_continue(entry, hlist) {
5138 fgd->entry = entry;
5139 return entry;
5140 }
5141
5142 idx++;
5143 }
5144
5145 for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
5146 head = &fgd->hash->buckets[i];
5147 hlist_for_each_entry(entry, head, hlist) {
5148 fgd->entry = entry;
5149 fgd->idx = i;
5150 return entry;
5151 }
5152 }
5153 return NULL;
5154}
5155
5156static void *
5157g_next(struct seq_file *m, void *v, loff_t *pos)
5158{
5159 (*pos)++;
5160 return __g_next(m, pos);
5161}
5162
5163static void *g_start(struct seq_file *m, loff_t *pos)
5164{
5165 struct ftrace_graph_data *fgd = m->private;
5166
5167 mutex_lock(&graph_lock);
5168
5169 if (fgd->type == GRAPH_FILTER_FUNCTION)
5170 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5171 lockdep_is_held(&graph_lock));
5172 else
5173 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5174 lockdep_is_held(&graph_lock));
5175
5176 /* Nothing, tell g_show to print all functions are enabled */
5177 if (ftrace_hash_empty(fgd->hash) && !*pos)
5178 return FTRACE_GRAPH_EMPTY;
5179
5180 fgd->idx = 0;
5181 fgd->entry = NULL;
5182 return __g_next(m, pos);
5183}
5184
5185static void g_stop(struct seq_file *m, void *p)
5186{
5187 mutex_unlock(&graph_lock);
5188}
5189
5190static int g_show(struct seq_file *m, void *v)
5191{
5192 struct ftrace_func_entry *entry = v;
5193
5194 if (!entry)
5195 return 0;
5196
5197 if (entry == FTRACE_GRAPH_EMPTY) {
5198 struct ftrace_graph_data *fgd = m->private;
5199
5200 if (fgd->type == GRAPH_FILTER_FUNCTION)
5201 seq_puts(m, "#### all functions enabled ####\n");
5202 else
5203 seq_puts(m, "#### no functions disabled ####\n");
5204 return 0;
5205 }
5206
5207 seq_printf(m, "%ps\n", (void *)entry->ip);
5208
5209 return 0;
5210}
5211
5212static const struct seq_operations ftrace_graph_seq_ops = {
5213 .start = g_start,
5214 .next = g_next,
5215 .stop = g_stop,
5216 .show = g_show,
5217};
5218
5219static int
5220__ftrace_graph_open(struct inode *inode, struct file *file,
5221 struct ftrace_graph_data *fgd)
5222{
5223 int ret;
5224 struct ftrace_hash *new_hash = NULL;
5225
5226 ret = security_locked_down(LOCKDOWN_TRACEFS);
5227 if (ret)
5228 return ret;
5229
5230 if (file->f_mode & FMODE_WRITE) {
5231 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
5232
5233 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
5234 return -ENOMEM;
5235
5236 if (file->f_flags & O_TRUNC)
5237 new_hash = alloc_ftrace_hash(size_bits);
5238 else
5239 new_hash = alloc_and_copy_ftrace_hash(size_bits,
5240 fgd->hash);
5241 if (!new_hash) {
5242 ret = -ENOMEM;
5243 goto out;
5244 }
5245 }
5246
5247 if (file->f_mode & FMODE_READ) {
5248 ret = seq_open(file, &ftrace_graph_seq_ops);
5249 if (!ret) {
5250 struct seq_file *m = file->private_data;
5251 m->private = fgd;
5252 } else {
5253 /* Failed */
5254 free_ftrace_hash(new_hash);
5255 new_hash = NULL;
5256 }
5257 } else
5258 file->private_data = fgd;
5259
5260out:
5261 if (ret < 0 && file->f_mode & FMODE_WRITE)
5262 trace_parser_put(&fgd->parser);
5263
5264 fgd->new_hash = new_hash;
5265
5266 /*
5267 * All uses of fgd->hash must be taken with the graph_lock
5268 * held. The graph_lock is going to be released, so force
5269 * fgd->hash to be reinitialized when it is taken again.
5270 */
5271 fgd->hash = NULL;
5272
5273 return ret;
5274}
5275
5276static int
5277ftrace_graph_open(struct inode *inode, struct file *file)
5278{
5279 struct ftrace_graph_data *fgd;
5280 int ret;
5281
5282 if (unlikely(ftrace_disabled))
5283 return -ENODEV;
5284
5285 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5286 if (fgd == NULL)
5287 return -ENOMEM;
5288
5289 mutex_lock(&graph_lock);
5290
5291 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5292 lockdep_is_held(&graph_lock));
5293 fgd->type = GRAPH_FILTER_FUNCTION;
5294 fgd->seq_ops = &ftrace_graph_seq_ops;
5295
5296 ret = __ftrace_graph_open(inode, file, fgd);
5297 if (ret < 0)
5298 kfree(fgd);
5299
5300 mutex_unlock(&graph_lock);
5301 return ret;
5302}
5303
5304static int
5305ftrace_graph_notrace_open(struct inode *inode, struct file *file)
5306{
5307 struct ftrace_graph_data *fgd;
5308 int ret;
5309
5310 if (unlikely(ftrace_disabled))
5311 return -ENODEV;
5312
5313 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5314 if (fgd == NULL)
5315 return -ENOMEM;
5316
5317 mutex_lock(&graph_lock);
5318
5319 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5320 lockdep_is_held(&graph_lock));
5321 fgd->type = GRAPH_FILTER_NOTRACE;
5322 fgd->seq_ops = &ftrace_graph_seq_ops;
5323
5324 ret = __ftrace_graph_open(inode, file, fgd);
5325 if (ret < 0)
5326 kfree(fgd);
5327
5328 mutex_unlock(&graph_lock);
5329 return ret;
5330}
5331
5332static int
5333ftrace_graph_release(struct inode *inode, struct file *file)
5334{
5335 struct ftrace_graph_data *fgd;
5336 struct ftrace_hash *old_hash, *new_hash;
5337 struct trace_parser *parser;
5338 int ret = 0;
5339
5340 if (file->f_mode & FMODE_READ) {
5341 struct seq_file *m = file->private_data;
5342
5343 fgd = m->private;
5344 seq_release(inode, file);
5345 } else {
5346 fgd = file->private_data;
5347 }
5348
5349
5350 if (file->f_mode & FMODE_WRITE) {
5351
5352 parser = &fgd->parser;
5353
5354 if (trace_parser_loaded((parser))) {
5355 ret = ftrace_graph_set_hash(fgd->new_hash,
5356 parser->buffer);
5357 }
5358
5359 trace_parser_put(parser);
5360
5361 new_hash = __ftrace_hash_move(fgd->new_hash);
5362 if (!new_hash) {
5363 ret = -ENOMEM;
5364 goto out;
5365 }
5366
5367 mutex_lock(&graph_lock);
5368
5369 if (fgd->type == GRAPH_FILTER_FUNCTION) {
5370 old_hash = rcu_dereference_protected(ftrace_graph_hash,
5371 lockdep_is_held(&graph_lock));
5372 rcu_assign_pointer(ftrace_graph_hash, new_hash);
5373 } else {
5374 old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5375 lockdep_is_held(&graph_lock));
5376 rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
5377 }
5378
5379 mutex_unlock(&graph_lock);
5380
5381 /* Wait till all users are no longer using the old hash */
5382 synchronize_rcu();
5383
5384 free_ftrace_hash(old_hash);
5385 }
5386
5387 out:
5388 free_ftrace_hash(fgd->new_hash);
5389 kfree(fgd);
5390
5391 return ret;
5392}
5393
5394static int
5395ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
5396{
5397 struct ftrace_glob func_g;
5398 struct dyn_ftrace *rec;
5399 struct ftrace_page *pg;
5400 struct ftrace_func_entry *entry;
5401 int fail = 1;
5402 int not;
5403
5404 /* decode regex */
5405 func_g.type = filter_parse_regex(buffer, strlen(buffer),
5406 &func_g.search, ¬);
5407
5408 func_g.len = strlen(func_g.search);
5409
5410 mutex_lock(&ftrace_lock);
5411
5412 if (unlikely(ftrace_disabled)) {
5413 mutex_unlock(&ftrace_lock);
5414 return -ENODEV;
5415 }
5416
5417 do_for_each_ftrace_rec(pg, rec) {
5418
5419 if (rec->flags & FTRACE_FL_DISABLED)
5420 continue;
5421
5422 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
5423 entry = ftrace_lookup_ip(hash, rec->ip);
5424
5425 if (!not) {
5426 fail = 0;
5427
5428 if (entry)
5429 continue;
5430 if (add_hash_entry(hash, rec->ip) < 0)
5431 goto out;
5432 } else {
5433 if (entry) {
5434 free_hash_entry(hash, entry);
5435 fail = 0;
5436 }
5437 }
5438 }
5439 } while_for_each_ftrace_rec();
5440out:
5441 mutex_unlock(&ftrace_lock);
5442
5443 if (fail)
5444 return -EINVAL;
5445
5446 return 0;
5447}
5448
5449static ssize_t
5450ftrace_graph_write(struct file *file, const char __user *ubuf,
5451 size_t cnt, loff_t *ppos)
5452{
5453 ssize_t read, ret = 0;
5454 struct ftrace_graph_data *fgd = file->private_data;
5455 struct trace_parser *parser;
5456
5457 if (!cnt)
5458 return 0;
5459
5460 /* Read mode uses seq functions */
5461 if (file->f_mode & FMODE_READ) {
5462 struct seq_file *m = file->private_data;
5463 fgd = m->private;
5464 }
5465
5466 parser = &fgd->parser;
5467
5468 read = trace_get_user(parser, ubuf, cnt, ppos);
5469
5470 if (read >= 0 && trace_parser_loaded(parser) &&
5471 !trace_parser_cont(parser)) {
5472
5473 ret = ftrace_graph_set_hash(fgd->new_hash,
5474 parser->buffer);
5475 trace_parser_clear(parser);
5476 }
5477
5478 if (!ret)
5479 ret = read;
5480
5481 return ret;
5482}
5483
5484static const struct file_operations ftrace_graph_fops = {
5485 .open = ftrace_graph_open,
5486 .read = seq_read,
5487 .write = ftrace_graph_write,
5488 .llseek = tracing_lseek,
5489 .release = ftrace_graph_release,
5490};
5491
5492static const struct file_operations ftrace_graph_notrace_fops = {
5493 .open = ftrace_graph_notrace_open,
5494 .read = seq_read,
5495 .write = ftrace_graph_write,
5496 .llseek = tracing_lseek,
5497 .release = ftrace_graph_release,
5498};
5499#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5500
5501void ftrace_create_filter_files(struct ftrace_ops *ops,
5502 struct dentry *parent)
5503{
5504
5505 trace_create_file("set_ftrace_filter", 0644, parent,
5506 ops, &ftrace_filter_fops);
5507
5508 trace_create_file("set_ftrace_notrace", 0644, parent,
5509 ops, &ftrace_notrace_fops);
5510}
5511
5512/*
5513 * The name "destroy_filter_files" is really a misnomer. Although
5514 * in the future, it may actually delete the files, but this is
5515 * really intended to make sure the ops passed in are disabled
5516 * and that when this function returns, the caller is free to
5517 * free the ops.
5518 *
5519 * The "destroy" name is only to match the "create" name that this
5520 * should be paired with.
5521 */
5522void ftrace_destroy_filter_files(struct ftrace_ops *ops)
5523{
5524 mutex_lock(&ftrace_lock);
5525 if (ops->flags & FTRACE_OPS_FL_ENABLED)
5526 ftrace_shutdown(ops, 0);
5527 ops->flags |= FTRACE_OPS_FL_DELETED;
5528 ftrace_free_filter(ops);
5529 mutex_unlock(&ftrace_lock);
5530}
5531
5532static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
5533{
5534
5535 trace_create_file("available_filter_functions", 0444,
5536 d_tracer, NULL, &ftrace_avail_fops);
5537
5538 trace_create_file("enabled_functions", 0444,
5539 d_tracer, NULL, &ftrace_enabled_fops);
5540
5541 ftrace_create_filter_files(&global_ops, d_tracer);
5542
5543#ifdef CONFIG_FUNCTION_GRAPH_TRACER
5544 trace_create_file("set_graph_function", 0644, d_tracer,
5545 NULL,
5546 &ftrace_graph_fops);
5547 trace_create_file("set_graph_notrace", 0644, d_tracer,
5548 NULL,
5549 &ftrace_graph_notrace_fops);
5550#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5551
5552 return 0;
5553}
5554
5555static int ftrace_cmp_ips(const void *a, const void *b)
5556{
5557 const unsigned long *ipa = a;
5558 const unsigned long *ipb = b;
5559
5560 if (*ipa > *ipb)
5561 return 1;
5562 if (*ipa < *ipb)
5563 return -1;
5564 return 0;
5565}
5566
5567static int ftrace_process_locs(struct module *mod,
5568 unsigned long *start,
5569 unsigned long *end)
5570{
5571 struct ftrace_page *start_pg;
5572 struct ftrace_page *pg;
5573 struct dyn_ftrace *rec;
5574 unsigned long count;
5575 unsigned long *p;
5576 unsigned long addr;
5577 unsigned long flags = 0; /* Shut up gcc */
5578 int ret = -ENOMEM;
5579
5580 count = end - start;
5581
5582 if (!count)
5583 return 0;
5584
5585 sort(start, count, sizeof(*start),
5586 ftrace_cmp_ips, NULL);
5587
5588 start_pg = ftrace_allocate_pages(count);
5589 if (!start_pg)
5590 return -ENOMEM;
5591
5592 mutex_lock(&ftrace_lock);
5593
5594 /*
5595 * Core and each module needs their own pages, as
5596 * modules will free them when they are removed.
5597 * Force a new page to be allocated for modules.
5598 */
5599 if (!mod) {
5600 WARN_ON(ftrace_pages || ftrace_pages_start);
5601 /* First initialization */
5602 ftrace_pages = ftrace_pages_start = start_pg;
5603 } else {
5604 if (!ftrace_pages)
5605 goto out;
5606
5607 if (WARN_ON(ftrace_pages->next)) {
5608 /* Hmm, we have free pages? */
5609 while (ftrace_pages->next)
5610 ftrace_pages = ftrace_pages->next;
5611 }
5612
5613 ftrace_pages->next = start_pg;
5614 }
5615
5616 p = start;
5617 pg = start_pg;
5618 while (p < end) {
5619 addr = ftrace_call_adjust(*p++);
5620 /*
5621 * Some architecture linkers will pad between
5622 * the different mcount_loc sections of different
5623 * object files to satisfy alignments.
5624 * Skip any NULL pointers.
5625 */
5626 if (!addr)
5627 continue;
5628
5629 if (pg->index == pg->size) {
5630 /* We should have allocated enough */
5631 if (WARN_ON(!pg->next))
5632 break;
5633 pg = pg->next;
5634 }
5635
5636 rec = &pg->records[pg->index++];
5637 rec->ip = addr;
5638 }
5639
5640 /* We should have used all pages */
5641 WARN_ON(pg->next);
5642
5643 /* Assign the last page to ftrace_pages */
5644 ftrace_pages = pg;
5645
5646 /*
5647 * We only need to disable interrupts on start up
5648 * because we are modifying code that an interrupt
5649 * may execute, and the modification is not atomic.
5650 * But for modules, nothing runs the code we modify
5651 * until we are finished with it, and there's no
5652 * reason to cause large interrupt latencies while we do it.
5653 */
5654 if (!mod)
5655 local_irq_save(flags);
5656 ftrace_update_code(mod, start_pg);
5657 if (!mod)
5658 local_irq_restore(flags);
5659 ret = 0;
5660 out:
5661 mutex_unlock(&ftrace_lock);
5662
5663 return ret;
5664}
5665
5666struct ftrace_mod_func {
5667 struct list_head list;
5668 char *name;
5669 unsigned long ip;
5670 unsigned int size;
5671};
5672
5673struct ftrace_mod_map {
5674 struct rcu_head rcu;
5675 struct list_head list;
5676 struct module *mod;
5677 unsigned long start_addr;
5678 unsigned long end_addr;
5679 struct list_head funcs;
5680 unsigned int num_funcs;
5681};
5682
5683#ifdef CONFIG_MODULES
5684
5685#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5686
5687static LIST_HEAD(ftrace_mod_maps);
5688
5689static int referenced_filters(struct dyn_ftrace *rec)
5690{
5691 struct ftrace_ops *ops;
5692 int cnt = 0;
5693
5694 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
5695 if (ops_references_rec(ops, rec))
5696 cnt++;
5697 }
5698
5699 return cnt;
5700}
5701
5702static void
5703clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
5704{
5705 struct ftrace_func_entry *entry;
5706 struct dyn_ftrace *rec;
5707 int i;
5708
5709 if (ftrace_hash_empty(hash))
5710 return;
5711
5712 for (i = 0; i < pg->index; i++) {
5713 rec = &pg->records[i];
5714 entry = __ftrace_lookup_ip(hash, rec->ip);
5715 /*
5716 * Do not allow this rec to match again.
5717 * Yeah, it may waste some memory, but will be removed
5718 * if/when the hash is modified again.
5719 */
5720 if (entry)
5721 entry->ip = 0;
5722 }
5723}
5724
5725/* Clear any records from hashs */
5726static void clear_mod_from_hashes(struct ftrace_page *pg)
5727{
5728 struct trace_array *tr;
5729
5730 mutex_lock(&trace_types_lock);
5731 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
5732 if (!tr->ops || !tr->ops->func_hash)
5733 continue;
5734 mutex_lock(&tr->ops->func_hash->regex_lock);
5735 clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash);
5736 clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash);
5737 mutex_unlock(&tr->ops->func_hash->regex_lock);
5738 }
5739 mutex_unlock(&trace_types_lock);
5740}
5741
5742static void ftrace_free_mod_map(struct rcu_head *rcu)
5743{
5744 struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
5745 struct ftrace_mod_func *mod_func;
5746 struct ftrace_mod_func *n;
5747
5748 /* All the contents of mod_map are now not visible to readers */
5749 list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
5750 kfree(mod_func->name);
5751 list_del(&mod_func->list);
5752 kfree(mod_func);
5753 }
5754
5755 kfree(mod_map);
5756}
5757
5758void ftrace_release_mod(struct module *mod)
5759{
5760 struct ftrace_mod_map *mod_map;
5761 struct ftrace_mod_map *n;
5762 struct dyn_ftrace *rec;
5763 struct ftrace_page **last_pg;
5764 struct ftrace_page *tmp_page = NULL;
5765 struct ftrace_page *pg;
5766 int order;
5767
5768 mutex_lock(&ftrace_lock);
5769
5770 if (ftrace_disabled)
5771 goto out_unlock;
5772
5773 list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
5774 if (mod_map->mod == mod) {
5775 list_del_rcu(&mod_map->list);
5776 call_rcu(&mod_map->rcu, ftrace_free_mod_map);
5777 break;
5778 }
5779 }
5780
5781 /*
5782 * Each module has its own ftrace_pages, remove
5783 * them from the list.
5784 */
5785 last_pg = &ftrace_pages_start;
5786 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5787 rec = &pg->records[0];
5788 if (within_module_core(rec->ip, mod) ||
5789 within_module_init(rec->ip, mod)) {
5790 /*
5791 * As core pages are first, the first
5792 * page should never be a module page.
5793 */
5794 if (WARN_ON(pg == ftrace_pages_start))
5795 goto out_unlock;
5796
5797 /* Check if we are deleting the last page */
5798 if (pg == ftrace_pages)
5799 ftrace_pages = next_to_ftrace_page(last_pg);
5800
5801 ftrace_update_tot_cnt -= pg->index;
5802 *last_pg = pg->next;
5803
5804 pg->next = tmp_page;
5805 tmp_page = pg;
5806 } else
5807 last_pg = &pg->next;
5808 }
5809 out_unlock:
5810 mutex_unlock(&ftrace_lock);
5811
5812 for (pg = tmp_page; pg; pg = tmp_page) {
5813
5814 /* Needs to be called outside of ftrace_lock */
5815 clear_mod_from_hashes(pg);
5816
5817 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5818 free_pages((unsigned long)pg->records, order);
5819 tmp_page = pg->next;
5820 kfree(pg);
5821 }
5822}
5823
5824void ftrace_module_enable(struct module *mod)
5825{
5826 struct dyn_ftrace *rec;
5827 struct ftrace_page *pg;
5828
5829 mutex_lock(&ftrace_lock);
5830
5831 if (ftrace_disabled)
5832 goto out_unlock;
5833
5834 /*
5835 * If the tracing is enabled, go ahead and enable the record.
5836 *
5837 * The reason not to enable the record immediately is the
5838 * inherent check of ftrace_make_nop/ftrace_make_call for
5839 * correct previous instructions. Making first the NOP
5840 * conversion puts the module to the correct state, thus
5841 * passing the ftrace_make_call check.
5842 *
5843 * We also delay this to after the module code already set the
5844 * text to read-only, as we now need to set it back to read-write
5845 * so that we can modify the text.
5846 */
5847 if (ftrace_start_up)
5848 ftrace_arch_code_modify_prepare();
5849
5850 do_for_each_ftrace_rec(pg, rec) {
5851 int cnt;
5852 /*
5853 * do_for_each_ftrace_rec() is a double loop.
5854 * module text shares the pg. If a record is
5855 * not part of this module, then skip this pg,
5856 * which the "break" will do.
5857 */
5858 if (!within_module_core(rec->ip, mod) &&
5859 !within_module_init(rec->ip, mod))
5860 break;
5861
5862 cnt = 0;
5863
5864 /*
5865 * When adding a module, we need to check if tracers are
5866 * currently enabled and if they are, and can trace this record,
5867 * we need to enable the module functions as well as update the
5868 * reference counts for those function records.
5869 */
5870 if (ftrace_start_up)
5871 cnt += referenced_filters(rec);
5872
5873 /* This clears FTRACE_FL_DISABLED */
5874 rec->flags = cnt;
5875
5876 if (ftrace_start_up && cnt) {
5877 int failed = __ftrace_replace_code(rec, 1);
5878 if (failed) {
5879 ftrace_bug(failed, rec);
5880 goto out_loop;
5881 }
5882 }
5883
5884 } while_for_each_ftrace_rec();
5885
5886 out_loop:
5887 if (ftrace_start_up)
5888 ftrace_arch_code_modify_post_process();
5889
5890 out_unlock:
5891 mutex_unlock(&ftrace_lock);
5892
5893 process_cached_mods(mod->name);
5894}
5895
5896void ftrace_module_init(struct module *mod)
5897{
5898 if (ftrace_disabled || !mod->num_ftrace_callsites)
5899 return;
5900
5901 ftrace_process_locs(mod, mod->ftrace_callsites,
5902 mod->ftrace_callsites + mod->num_ftrace_callsites);
5903}
5904
5905static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
5906 struct dyn_ftrace *rec)
5907{
5908 struct ftrace_mod_func *mod_func;
5909 unsigned long symsize;
5910 unsigned long offset;
5911 char str[KSYM_SYMBOL_LEN];
5912 char *modname;
5913 const char *ret;
5914
5915 ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str);
5916 if (!ret)
5917 return;
5918
5919 mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
5920 if (!mod_func)
5921 return;
5922
5923 mod_func->name = kstrdup(str, GFP_KERNEL);
5924 if (!mod_func->name) {
5925 kfree(mod_func);
5926 return;
5927 }
5928
5929 mod_func->ip = rec->ip - offset;
5930 mod_func->size = symsize;
5931
5932 mod_map->num_funcs++;
5933
5934 list_add_rcu(&mod_func->list, &mod_map->funcs);
5935}
5936
5937static struct ftrace_mod_map *
5938allocate_ftrace_mod_map(struct module *mod,
5939 unsigned long start, unsigned long end)
5940{
5941 struct ftrace_mod_map *mod_map;
5942
5943 mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
5944 if (!mod_map)
5945 return NULL;
5946
5947 mod_map->mod = mod;
5948 mod_map->start_addr = start;
5949 mod_map->end_addr = end;
5950 mod_map->num_funcs = 0;
5951
5952 INIT_LIST_HEAD_RCU(&mod_map->funcs);
5953
5954 list_add_rcu(&mod_map->list, &ftrace_mod_maps);
5955
5956 return mod_map;
5957}
5958
5959static const char *
5960ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
5961 unsigned long addr, unsigned long *size,
5962 unsigned long *off, char *sym)
5963{
5964 struct ftrace_mod_func *found_func = NULL;
5965 struct ftrace_mod_func *mod_func;
5966
5967 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
5968 if (addr >= mod_func->ip &&
5969 addr < mod_func->ip + mod_func->size) {
5970 found_func = mod_func;
5971 break;
5972 }
5973 }
5974
5975 if (found_func) {
5976 if (size)
5977 *size = found_func->size;
5978 if (off)
5979 *off = addr - found_func->ip;
5980 if (sym)
5981 strlcpy(sym, found_func->name, KSYM_NAME_LEN);
5982
5983 return found_func->name;
5984 }
5985
5986 return NULL;
5987}
5988
5989const char *
5990ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
5991 unsigned long *off, char **modname, char *sym)
5992{
5993 struct ftrace_mod_map *mod_map;
5994 const char *ret = NULL;
5995
5996 /* mod_map is freed via call_rcu() */
5997 preempt_disable();
5998 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5999 ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
6000 if (ret) {
6001 if (modname)
6002 *modname = mod_map->mod->name;
6003 break;
6004 }
6005 }
6006 preempt_enable();
6007
6008 return ret;
6009}
6010
6011int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
6012 char *type, char *name,
6013 char *module_name, int *exported)
6014{
6015 struct ftrace_mod_map *mod_map;
6016 struct ftrace_mod_func *mod_func;
6017
6018 preempt_disable();
6019 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
6020
6021 if (symnum >= mod_map->num_funcs) {
6022 symnum -= mod_map->num_funcs;
6023 continue;
6024 }
6025
6026 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
6027 if (symnum > 1) {
6028 symnum--;
6029 continue;
6030 }
6031
6032 *value = mod_func->ip;
6033 *type = 'T';
6034 strlcpy(name, mod_func->name, KSYM_NAME_LEN);
6035 strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
6036 *exported = 1;
6037 preempt_enable();
6038 return 0;
6039 }
6040 WARN_ON(1);
6041 break;
6042 }
6043 preempt_enable();
6044 return -ERANGE;
6045}
6046
6047#else
6048static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6049 struct dyn_ftrace *rec) { }
6050static inline struct ftrace_mod_map *
6051allocate_ftrace_mod_map(struct module *mod,
6052 unsigned long start, unsigned long end)
6053{
6054 return NULL;
6055}
6056#endif /* CONFIG_MODULES */
6057
6058struct ftrace_init_func {
6059 struct list_head list;
6060 unsigned long ip;
6061};
6062
6063/* Clear any init ips from hashes */
6064static void
6065clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
6066{
6067 struct ftrace_func_entry *entry;
6068
6069 entry = ftrace_lookup_ip(hash, func->ip);
6070 /*
6071 * Do not allow this rec to match again.
6072 * Yeah, it may waste some memory, but will be removed
6073 * if/when the hash is modified again.
6074 */
6075 if (entry)
6076 entry->ip = 0;
6077}
6078
6079static void
6080clear_func_from_hashes(struct ftrace_init_func *func)
6081{
6082 struct trace_array *tr;
6083
6084 mutex_lock(&trace_types_lock);
6085 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6086 if (!tr->ops || !tr->ops->func_hash)
6087 continue;
6088 mutex_lock(&tr->ops->func_hash->regex_lock);
6089 clear_func_from_hash(func, tr->ops->func_hash->filter_hash);
6090 clear_func_from_hash(func, tr->ops->func_hash->notrace_hash);
6091 mutex_unlock(&tr->ops->func_hash->regex_lock);
6092 }
6093 mutex_unlock(&trace_types_lock);
6094}
6095
6096static void add_to_clear_hash_list(struct list_head *clear_list,
6097 struct dyn_ftrace *rec)
6098{
6099 struct ftrace_init_func *func;
6100
6101 func = kmalloc(sizeof(*func), GFP_KERNEL);
6102 if (!func) {
6103 WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
6104 return;
6105 }
6106
6107 func->ip = rec->ip;
6108 list_add(&func->list, clear_list);
6109}
6110
6111void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
6112{
6113 unsigned long start = (unsigned long)(start_ptr);
6114 unsigned long end = (unsigned long)(end_ptr);
6115 struct ftrace_page **last_pg = &ftrace_pages_start;
6116 struct ftrace_page *pg;
6117 struct dyn_ftrace *rec;
6118 struct dyn_ftrace key;
6119 struct ftrace_mod_map *mod_map = NULL;
6120 struct ftrace_init_func *func, *func_next;
6121 struct list_head clear_hash;
6122 int order;
6123
6124 INIT_LIST_HEAD(&clear_hash);
6125
6126 key.ip = start;
6127 key.flags = end; /* overload flags, as it is unsigned long */
6128
6129 mutex_lock(&ftrace_lock);
6130
6131 /*
6132 * If we are freeing module init memory, then check if
6133 * any tracer is active. If so, we need to save a mapping of
6134 * the module functions being freed with the address.
6135 */
6136 if (mod && ftrace_ops_list != &ftrace_list_end)
6137 mod_map = allocate_ftrace_mod_map(mod, start, end);
6138
6139 for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
6140 if (end < pg->records[0].ip ||
6141 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
6142 continue;
6143 again:
6144 rec = bsearch(&key, pg->records, pg->index,
6145 sizeof(struct dyn_ftrace),
6146 ftrace_cmp_recs);
6147 if (!rec)
6148 continue;
6149
6150 /* rec will be cleared from hashes after ftrace_lock unlock */
6151 add_to_clear_hash_list(&clear_hash, rec);
6152
6153 if (mod_map)
6154 save_ftrace_mod_rec(mod_map, rec);
6155
6156 pg->index--;
6157 ftrace_update_tot_cnt--;
6158 if (!pg->index) {
6159 *last_pg = pg->next;
6160 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
6161 free_pages((unsigned long)pg->records, order);
6162 kfree(pg);
6163 pg = container_of(last_pg, struct ftrace_page, next);
6164 if (!(*last_pg))
6165 ftrace_pages = pg;
6166 continue;
6167 }
6168 memmove(rec, rec + 1,
6169 (pg->index - (rec - pg->records)) * sizeof(*rec));
6170 /* More than one function may be in this block */
6171 goto again;
6172 }
6173 mutex_unlock(&ftrace_lock);
6174
6175 list_for_each_entry_safe(func, func_next, &clear_hash, list) {
6176 clear_func_from_hashes(func);
6177 kfree(func);
6178 }
6179}
6180
6181void __init ftrace_free_init_mem(void)
6182{
6183 void *start = (void *)(&__init_begin);
6184 void *end = (void *)(&__init_end);
6185
6186 ftrace_free_mem(NULL, start, end);
6187}
6188
6189void __init ftrace_init(void)
6190{
6191 extern unsigned long __start_mcount_loc[];
6192 extern unsigned long __stop_mcount_loc[];
6193 unsigned long count, flags;
6194 int ret;
6195
6196 local_irq_save(flags);
6197 ret = ftrace_dyn_arch_init();
6198 local_irq_restore(flags);
6199 if (ret)
6200 goto failed;
6201
6202 count = __stop_mcount_loc - __start_mcount_loc;
6203 if (!count) {
6204 pr_info("ftrace: No functions to be traced?\n");
6205 goto failed;
6206 }
6207
6208 pr_info("ftrace: allocating %ld entries in %ld pages\n",
6209 count, count / ENTRIES_PER_PAGE + 1);
6210
6211 last_ftrace_enabled = ftrace_enabled = 1;
6212
6213 ret = ftrace_process_locs(NULL,
6214 __start_mcount_loc,
6215 __stop_mcount_loc);
6216
6217 set_ftrace_early_filters();
6218
6219 return;
6220 failed:
6221 ftrace_disabled = 1;
6222}
6223
6224/* Do nothing if arch does not support this */
6225void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
6226{
6227}
6228
6229static void ftrace_update_trampoline(struct ftrace_ops *ops)
6230{
6231 arch_ftrace_update_trampoline(ops);
6232}
6233
6234void ftrace_init_trace_array(struct trace_array *tr)
6235{
6236 INIT_LIST_HEAD(&tr->func_probes);
6237 INIT_LIST_HEAD(&tr->mod_trace);
6238 INIT_LIST_HEAD(&tr->mod_notrace);
6239}
6240#else
6241
6242struct ftrace_ops global_ops = {
6243 .func = ftrace_stub,
6244 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6245 FTRACE_OPS_FL_INITIALIZED |
6246 FTRACE_OPS_FL_PID,
6247};
6248
6249static int __init ftrace_nodyn_init(void)
6250{
6251 ftrace_enabled = 1;
6252 return 0;
6253}
6254core_initcall(ftrace_nodyn_init);
6255
6256static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
6257static inline void ftrace_startup_enable(int command) { }
6258static inline void ftrace_startup_all(int command) { }
6259
6260# define ftrace_startup_sysctl() do { } while (0)
6261# define ftrace_shutdown_sysctl() do { } while (0)
6262
6263static void ftrace_update_trampoline(struct ftrace_ops *ops)
6264{
6265}
6266
6267#endif /* CONFIG_DYNAMIC_FTRACE */
6268
6269__init void ftrace_init_global_array_ops(struct trace_array *tr)
6270{
6271 tr->ops = &global_ops;
6272 tr->ops->private = tr;
6273 ftrace_init_trace_array(tr);
6274}
6275
6276void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
6277{
6278 /* If we filter on pids, update to use the pid function */
6279 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
6280 if (WARN_ON(tr->ops->func != ftrace_stub))
6281 printk("ftrace ops had %pS for function\n",
6282 tr->ops->func);
6283 }
6284 tr->ops->func = func;
6285 tr->ops->private = tr;
6286}
6287
6288void ftrace_reset_array_ops(struct trace_array *tr)
6289{
6290 tr->ops->func = ftrace_stub;
6291}
6292
6293static nokprobe_inline void
6294__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6295 struct ftrace_ops *ignored, struct pt_regs *regs)
6296{
6297 struct ftrace_ops *op;
6298 int bit;
6299
6300 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6301 if (bit < 0)
6302 return;
6303
6304 /*
6305 * Some of the ops may be dynamically allocated,
6306 * they must be freed after a synchronize_rcu().
6307 */
6308 preempt_disable_notrace();
6309
6310 do_for_each_ftrace_op(op, ftrace_ops_list) {
6311 /* Stub functions don't need to be called nor tested */
6312 if (op->flags & FTRACE_OPS_FL_STUB)
6313 continue;
6314 /*
6315 * Check the following for each ops before calling their func:
6316 * if RCU flag is set, then rcu_is_watching() must be true
6317 * if PER_CPU is set, then ftrace_function_local_disable()
6318 * must be false
6319 * Otherwise test if the ip matches the ops filter
6320 *
6321 * If any of the above fails then the op->func() is not executed.
6322 */
6323 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
6324 ftrace_ops_test(op, ip, regs)) {
6325 if (FTRACE_WARN_ON(!op->func)) {
6326 pr_warn("op=%p %pS\n", op, op);
6327 goto out;
6328 }
6329 op->func(ip, parent_ip, op, regs);
6330 }
6331 } while_for_each_ftrace_op(op);
6332out:
6333 preempt_enable_notrace();
6334 trace_clear_recursion(bit);
6335}
6336
6337/*
6338 * Some archs only support passing ip and parent_ip. Even though
6339 * the list function ignores the op parameter, we do not want any
6340 * C side effects, where a function is called without the caller
6341 * sending a third parameter.
6342 * Archs are to support both the regs and ftrace_ops at the same time.
6343 * If they support ftrace_ops, it is assumed they support regs.
6344 * If call backs want to use regs, they must either check for regs
6345 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6346 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6347 * An architecture can pass partial regs with ftrace_ops and still
6348 * set the ARCH_SUPPORTS_FTRACE_OPS.
6349 */
6350#if ARCH_SUPPORTS_FTRACE_OPS
6351static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6352 struct ftrace_ops *op, struct pt_regs *regs)
6353{
6354 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
6355}
6356NOKPROBE_SYMBOL(ftrace_ops_list_func);
6357#else
6358static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
6359{
6360 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
6361}
6362NOKPROBE_SYMBOL(ftrace_ops_no_ops);
6363#endif
6364
6365/*
6366 * If there's only one function registered but it does not support
6367 * recursion, needs RCU protection and/or requires per cpu handling, then
6368 * this function will be called by the mcount trampoline.
6369 */
6370static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
6371 struct ftrace_ops *op, struct pt_regs *regs)
6372{
6373 int bit;
6374
6375 if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
6376 return;
6377
6378 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6379 if (bit < 0)
6380 return;
6381
6382 preempt_disable_notrace();
6383
6384 op->func(ip, parent_ip, op, regs);
6385
6386 preempt_enable_notrace();
6387 trace_clear_recursion(bit);
6388}
6389NOKPROBE_SYMBOL(ftrace_ops_assist_func);
6390
6391/**
6392 * ftrace_ops_get_func - get the function a trampoline should call
6393 * @ops: the ops to get the function for
6394 *
6395 * Normally the mcount trampoline will call the ops->func, but there
6396 * are times that it should not. For example, if the ops does not
6397 * have its own recursion protection, then it should call the
6398 * ftrace_ops_assist_func() instead.
6399 *
6400 * Returns the function that the trampoline should call for @ops.
6401 */
6402ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
6403{
6404 /*
6405 * If the function does not handle recursion, needs to be RCU safe,
6406 * or does per cpu logic, then we need to call the assist handler.
6407 */
6408 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
6409 ops->flags & FTRACE_OPS_FL_RCU)
6410 return ftrace_ops_assist_func;
6411
6412 return ops->func;
6413}
6414
6415static void
6416ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
6417 struct task_struct *prev, struct task_struct *next)
6418{
6419 struct trace_array *tr = data;
6420 struct trace_pid_list *pid_list;
6421
6422 pid_list = rcu_dereference_sched(tr->function_pids);
6423
6424 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6425 trace_ignore_this_task(pid_list, next));
6426}
6427
6428static void
6429ftrace_pid_follow_sched_process_fork(void *data,
6430 struct task_struct *self,
6431 struct task_struct *task)
6432{
6433 struct trace_pid_list *pid_list;
6434 struct trace_array *tr = data;
6435
6436 pid_list = rcu_dereference_sched(tr->function_pids);
6437 trace_filter_add_remove_task(pid_list, self, task);
6438}
6439
6440static void
6441ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
6442{
6443 struct trace_pid_list *pid_list;
6444 struct trace_array *tr = data;
6445
6446 pid_list = rcu_dereference_sched(tr->function_pids);
6447 trace_filter_add_remove_task(pid_list, NULL, task);
6448}
6449
6450void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
6451{
6452 if (enable) {
6453 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6454 tr);
6455 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6456 tr);
6457 } else {
6458 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6459 tr);
6460 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6461 tr);
6462 }
6463}
6464
6465static void clear_ftrace_pids(struct trace_array *tr)
6466{
6467 struct trace_pid_list *pid_list;
6468 int cpu;
6469
6470 pid_list = rcu_dereference_protected(tr->function_pids,
6471 lockdep_is_held(&ftrace_lock));
6472 if (!pid_list)
6473 return;
6474
6475 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6476
6477 for_each_possible_cpu(cpu)
6478 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
6479
6480 rcu_assign_pointer(tr->function_pids, NULL);
6481
6482 /* Wait till all users are no longer using pid filtering */
6483 synchronize_rcu();
6484
6485 trace_free_pid_list(pid_list);
6486}
6487
6488void ftrace_clear_pids(struct trace_array *tr)
6489{
6490 mutex_lock(&ftrace_lock);
6491
6492 clear_ftrace_pids(tr);
6493
6494 mutex_unlock(&ftrace_lock);
6495}
6496
6497static void ftrace_pid_reset(struct trace_array *tr)
6498{
6499 mutex_lock(&ftrace_lock);
6500 clear_ftrace_pids(tr);
6501
6502 ftrace_update_pid_func();
6503 ftrace_startup_all(0);
6504
6505 mutex_unlock(&ftrace_lock);
6506}
6507
6508/* Greater than any max PID */
6509#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
6510
6511static void *fpid_start(struct seq_file *m, loff_t *pos)
6512 __acquires(RCU)
6513{
6514 struct trace_pid_list *pid_list;
6515 struct trace_array *tr = m->private;
6516
6517 mutex_lock(&ftrace_lock);
6518 rcu_read_lock_sched();
6519
6520 pid_list = rcu_dereference_sched(tr->function_pids);
6521
6522 if (!pid_list)
6523 return !(*pos) ? FTRACE_NO_PIDS : NULL;
6524
6525 return trace_pid_start(pid_list, pos);
6526}
6527
6528static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
6529{
6530 struct trace_array *tr = m->private;
6531 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
6532
6533 if (v == FTRACE_NO_PIDS)
6534 return NULL;
6535
6536 return trace_pid_next(pid_list, v, pos);
6537}
6538
6539static void fpid_stop(struct seq_file *m, void *p)
6540 __releases(RCU)
6541{
6542 rcu_read_unlock_sched();
6543 mutex_unlock(&ftrace_lock);
6544}
6545
6546static int fpid_show(struct seq_file *m, void *v)
6547{
6548 if (v == FTRACE_NO_PIDS) {
6549 seq_puts(m, "no pid\n");
6550 return 0;
6551 }
6552
6553 return trace_pid_show(m, v);
6554}
6555
6556static const struct seq_operations ftrace_pid_sops = {
6557 .start = fpid_start,
6558 .next = fpid_next,
6559 .stop = fpid_stop,
6560 .show = fpid_show,
6561};
6562
6563static int
6564ftrace_pid_open(struct inode *inode, struct file *file)
6565{
6566 struct trace_array *tr = inode->i_private;
6567 struct seq_file *m;
6568 int ret = 0;
6569
6570 ret = tracing_check_open_get_tr(tr);
6571 if (ret)
6572 return ret;
6573
6574 if ((file->f_mode & FMODE_WRITE) &&
6575 (file->f_flags & O_TRUNC))
6576 ftrace_pid_reset(tr);
6577
6578 ret = seq_open(file, &ftrace_pid_sops);
6579 if (ret < 0) {
6580 trace_array_put(tr);
6581 } else {
6582 m = file->private_data;
6583 /* copy tr over to seq ops */
6584 m->private = tr;
6585 }
6586
6587 return ret;
6588}
6589
6590static void ignore_task_cpu(void *data)
6591{
6592 struct trace_array *tr = data;
6593 struct trace_pid_list *pid_list;
6594
6595 /*
6596 * This function is called by on_each_cpu() while the
6597 * event_mutex is held.
6598 */
6599 pid_list = rcu_dereference_protected(tr->function_pids,
6600 mutex_is_locked(&ftrace_lock));
6601
6602 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6603 trace_ignore_this_task(pid_list, current));
6604}
6605
6606static ssize_t
6607ftrace_pid_write(struct file *filp, const char __user *ubuf,
6608 size_t cnt, loff_t *ppos)
6609{
6610 struct seq_file *m = filp->private_data;
6611 struct trace_array *tr = m->private;
6612 struct trace_pid_list *filtered_pids = NULL;
6613 struct trace_pid_list *pid_list;
6614 ssize_t ret;
6615
6616 if (!cnt)
6617 return 0;
6618
6619 mutex_lock(&ftrace_lock);
6620
6621 filtered_pids = rcu_dereference_protected(tr->function_pids,
6622 lockdep_is_held(&ftrace_lock));
6623
6624 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
6625 if (ret < 0)
6626 goto out;
6627
6628 rcu_assign_pointer(tr->function_pids, pid_list);
6629
6630 if (filtered_pids) {
6631 synchronize_rcu();
6632 trace_free_pid_list(filtered_pids);
6633 } else if (pid_list) {
6634 /* Register a probe to set whether to ignore the tracing of a task */
6635 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6636 }
6637
6638 /*
6639 * Ignoring of pids is done at task switch. But we have to
6640 * check for those tasks that are currently running.
6641 * Always do this in case a pid was appended or removed.
6642 */
6643 on_each_cpu(ignore_task_cpu, tr, 1);
6644
6645 ftrace_update_pid_func();
6646 ftrace_startup_all(0);
6647 out:
6648 mutex_unlock(&ftrace_lock);
6649
6650 if (ret > 0)
6651 *ppos += ret;
6652
6653 return ret;
6654}
6655
6656static int
6657ftrace_pid_release(struct inode *inode, struct file *file)
6658{
6659 struct trace_array *tr = inode->i_private;
6660
6661 trace_array_put(tr);
6662
6663 return seq_release(inode, file);
6664}
6665
6666static const struct file_operations ftrace_pid_fops = {
6667 .open = ftrace_pid_open,
6668 .write = ftrace_pid_write,
6669 .read = seq_read,
6670 .llseek = tracing_lseek,
6671 .release = ftrace_pid_release,
6672};
6673
6674void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
6675{
6676 trace_create_file("set_ftrace_pid", 0644, d_tracer,
6677 tr, &ftrace_pid_fops);
6678}
6679
6680void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
6681 struct dentry *d_tracer)
6682{
6683 /* Only the top level directory has the dyn_tracefs and profile */
6684 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
6685
6686 ftrace_init_dyn_tracefs(d_tracer);
6687 ftrace_profile_tracefs(d_tracer);
6688}
6689
6690/**
6691 * ftrace_kill - kill ftrace
6692 *
6693 * This function should be used by panic code. It stops ftrace
6694 * but in a not so nice way. If you need to simply kill ftrace
6695 * from a non-atomic section, use ftrace_kill.
6696 */
6697void ftrace_kill(void)
6698{
6699 ftrace_disabled = 1;
6700 ftrace_enabled = 0;
6701 ftrace_trace_function = ftrace_stub;
6702}
6703
6704/**
6705 * Test if ftrace is dead or not.
6706 */
6707int ftrace_is_dead(void)
6708{
6709 return ftrace_disabled;
6710}
6711
6712/**
6713 * register_ftrace_function - register a function for profiling
6714 * @ops - ops structure that holds the function for profiling.
6715 *
6716 * Register a function to be called by all functions in the
6717 * kernel.
6718 *
6719 * Note: @ops->func and all the functions it calls must be labeled
6720 * with "notrace", otherwise it will go into a
6721 * recursive loop.
6722 */
6723int register_ftrace_function(struct ftrace_ops *ops)
6724{
6725 int ret = -1;
6726
6727 ftrace_ops_init(ops);
6728
6729 mutex_lock(&ftrace_lock);
6730
6731 ret = ftrace_startup(ops, 0);
6732
6733 mutex_unlock(&ftrace_lock);
6734
6735 return ret;
6736}
6737EXPORT_SYMBOL_GPL(register_ftrace_function);
6738
6739/**
6740 * unregister_ftrace_function - unregister a function for profiling.
6741 * @ops - ops structure that holds the function to unregister
6742 *
6743 * Unregister a function that was added to be called by ftrace profiling.
6744 */
6745int unregister_ftrace_function(struct ftrace_ops *ops)
6746{
6747 int ret;
6748
6749 mutex_lock(&ftrace_lock);
6750 ret = ftrace_shutdown(ops, 0);
6751 mutex_unlock(&ftrace_lock);
6752
6753 return ret;
6754}
6755EXPORT_SYMBOL_GPL(unregister_ftrace_function);
6756
6757int
6758ftrace_enable_sysctl(struct ctl_table *table, int write,
6759 void __user *buffer, size_t *lenp,
6760 loff_t *ppos)
6761{
6762 int ret = -ENODEV;
6763
6764 mutex_lock(&ftrace_lock);
6765
6766 if (unlikely(ftrace_disabled))
6767 goto out;
6768
6769 ret = proc_dointvec(table, write, buffer, lenp, ppos);
6770
6771 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
6772 goto out;
6773
6774 last_ftrace_enabled = !!ftrace_enabled;
6775
6776 if (ftrace_enabled) {
6777
6778 /* we are starting ftrace again */
6779 if (rcu_dereference_protected(ftrace_ops_list,
6780 lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
6781 update_ftrace_function();
6782
6783 ftrace_startup_sysctl();
6784
6785 } else {
6786 /* stopping ftrace calls (just send to ftrace_stub) */
6787 ftrace_trace_function = ftrace_stub;
6788
6789 ftrace_shutdown_sysctl();
6790 }
6791
6792 out:
6793 mutex_unlock(&ftrace_lock);
6794 return ret;
6795}
1/*
2 * Infrastructure for profiling code inserted by 'gcc -pg'.
3 *
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
6 *
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
9 *
10 * Based on code in the latency_tracer, that is:
11 *
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 William Lee Irwin III
14 */
15
16#include <linux/stop_machine.h>
17#include <linux/clocksource.h>
18#include <linux/kallsyms.h>
19#include <linux/seq_file.h>
20#include <linux/suspend.h>
21#include <linux/debugfs.h>
22#include <linux/hardirq.h>
23#include <linux/kthread.h>
24#include <linux/uaccess.h>
25#include <linux/ftrace.h>
26#include <linux/sysctl.h>
27#include <linux/slab.h>
28#include <linux/ctype.h>
29#include <linux/list.h>
30#include <linux/hash.h>
31#include <linux/rcupdate.h>
32
33#include <trace/events/sched.h>
34
35#include <asm/setup.h>
36
37#include "trace_output.h"
38#include "trace_stat.h"
39
40#define FTRACE_WARN_ON(cond) \
41 ({ \
42 int ___r = cond; \
43 if (WARN_ON(___r)) \
44 ftrace_kill(); \
45 ___r; \
46 })
47
48#define FTRACE_WARN_ON_ONCE(cond) \
49 ({ \
50 int ___r = cond; \
51 if (WARN_ON_ONCE(___r)) \
52 ftrace_kill(); \
53 ___r; \
54 })
55
56/* hash bits for specific function selection */
57#define FTRACE_HASH_BITS 7
58#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
59#define FTRACE_HASH_DEFAULT_BITS 10
60#define FTRACE_HASH_MAX_BITS 12
61
62/* ftrace_enabled is a method to turn ftrace on or off */
63int ftrace_enabled __read_mostly;
64static int last_ftrace_enabled;
65
66/* Quick disabling of function tracer. */
67int function_trace_stop;
68
69/* List for set_ftrace_pid's pids. */
70LIST_HEAD(ftrace_pids);
71struct ftrace_pid {
72 struct list_head list;
73 struct pid *pid;
74};
75
76/*
77 * ftrace_disabled is set when an anomaly is discovered.
78 * ftrace_disabled is much stronger than ftrace_enabled.
79 */
80static int ftrace_disabled __read_mostly;
81
82static DEFINE_MUTEX(ftrace_lock);
83
84static struct ftrace_ops ftrace_list_end __read_mostly = {
85 .func = ftrace_stub,
86};
87
88static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
89static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
90ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
91static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub;
92ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
93ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
94static struct ftrace_ops global_ops;
95
96static void
97ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
98
99/*
100 * Traverse the ftrace_global_list, invoking all entries. The reason that we
101 * can use rcu_dereference_raw() is that elements removed from this list
102 * are simply leaked, so there is no need to interact with a grace-period
103 * mechanism. The rcu_dereference_raw() calls are needed to handle
104 * concurrent insertions into the ftrace_global_list.
105 *
106 * Silly Alpha and silly pointer-speculation compiler optimizations!
107 */
108static void ftrace_global_list_func(unsigned long ip,
109 unsigned long parent_ip)
110{
111 struct ftrace_ops *op;
112
113 if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
114 return;
115
116 trace_recursion_set(TRACE_GLOBAL_BIT);
117 op = rcu_dereference_raw(ftrace_global_list); /*see above*/
118 while (op != &ftrace_list_end) {
119 op->func(ip, parent_ip);
120 op = rcu_dereference_raw(op->next); /*see above*/
121 };
122 trace_recursion_clear(TRACE_GLOBAL_BIT);
123}
124
125static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
126{
127 if (!test_tsk_trace_trace(current))
128 return;
129
130 ftrace_pid_function(ip, parent_ip);
131}
132
133static void set_ftrace_pid_function(ftrace_func_t func)
134{
135 /* do not set ftrace_pid_function to itself! */
136 if (func != ftrace_pid_func)
137 ftrace_pid_function = func;
138}
139
140/**
141 * clear_ftrace_function - reset the ftrace function
142 *
143 * This NULLs the ftrace function and in essence stops
144 * tracing. There may be lag
145 */
146void clear_ftrace_function(void)
147{
148 ftrace_trace_function = ftrace_stub;
149 __ftrace_trace_function = ftrace_stub;
150 __ftrace_trace_function_delay = ftrace_stub;
151 ftrace_pid_function = ftrace_stub;
152}
153
154#undef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
155#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
156/*
157 * For those archs that do not test ftrace_trace_stop in their
158 * mcount call site, we need to do it from C.
159 */
160static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
161{
162 if (function_trace_stop)
163 return;
164
165 __ftrace_trace_function(ip, parent_ip);
166}
167#endif
168
169static void update_global_ops(void)
170{
171 ftrace_func_t func;
172
173 /*
174 * If there's only one function registered, then call that
175 * function directly. Otherwise, we need to iterate over the
176 * registered callers.
177 */
178 if (ftrace_global_list == &ftrace_list_end ||
179 ftrace_global_list->next == &ftrace_list_end)
180 func = ftrace_global_list->func;
181 else
182 func = ftrace_global_list_func;
183
184 /* If we filter on pids, update to use the pid function */
185 if (!list_empty(&ftrace_pids)) {
186 set_ftrace_pid_function(func);
187 func = ftrace_pid_func;
188 }
189
190 global_ops.func = func;
191}
192
193static void update_ftrace_function(void)
194{
195 ftrace_func_t func;
196
197 update_global_ops();
198
199 /*
200 * If we are at the end of the list and this ops is
201 * not dynamic, then have the mcount trampoline call
202 * the function directly
203 */
204 if (ftrace_ops_list == &ftrace_list_end ||
205 (ftrace_ops_list->next == &ftrace_list_end &&
206 !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC)))
207 func = ftrace_ops_list->func;
208 else
209 func = ftrace_ops_list_func;
210
211#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
212 ftrace_trace_function = func;
213#else
214#ifdef CONFIG_DYNAMIC_FTRACE
215 /* do not update till all functions have been modified */
216 __ftrace_trace_function_delay = func;
217#else
218 __ftrace_trace_function = func;
219#endif
220 ftrace_trace_function = ftrace_test_stop_func;
221#endif
222}
223
224static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
225{
226 ops->next = *list;
227 /*
228 * We are entering ops into the list but another
229 * CPU might be walking that list. We need to make sure
230 * the ops->next pointer is valid before another CPU sees
231 * the ops pointer included into the list.
232 */
233 rcu_assign_pointer(*list, ops);
234}
235
236static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
237{
238 struct ftrace_ops **p;
239
240 /*
241 * If we are removing the last function, then simply point
242 * to the ftrace_stub.
243 */
244 if (*list == ops && ops->next == &ftrace_list_end) {
245 *list = &ftrace_list_end;
246 return 0;
247 }
248
249 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
250 if (*p == ops)
251 break;
252
253 if (*p != ops)
254 return -1;
255
256 *p = (*p)->next;
257 return 0;
258}
259
260static int __register_ftrace_function(struct ftrace_ops *ops)
261{
262 if (ftrace_disabled)
263 return -ENODEV;
264
265 if (FTRACE_WARN_ON(ops == &global_ops))
266 return -EINVAL;
267
268 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
269 return -EBUSY;
270
271 if (!core_kernel_data((unsigned long)ops))
272 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
273
274 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
275 int first = ftrace_global_list == &ftrace_list_end;
276 add_ftrace_ops(&ftrace_global_list, ops);
277 ops->flags |= FTRACE_OPS_FL_ENABLED;
278 if (first)
279 add_ftrace_ops(&ftrace_ops_list, &global_ops);
280 } else
281 add_ftrace_ops(&ftrace_ops_list, ops);
282
283 if (ftrace_enabled)
284 update_ftrace_function();
285
286 return 0;
287}
288
289static int __unregister_ftrace_function(struct ftrace_ops *ops)
290{
291 int ret;
292
293 if (ftrace_disabled)
294 return -ENODEV;
295
296 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
297 return -EBUSY;
298
299 if (FTRACE_WARN_ON(ops == &global_ops))
300 return -EINVAL;
301
302 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
303 ret = remove_ftrace_ops(&ftrace_global_list, ops);
304 if (!ret && ftrace_global_list == &ftrace_list_end)
305 ret = remove_ftrace_ops(&ftrace_ops_list, &global_ops);
306 if (!ret)
307 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
308 } else
309 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
310
311 if (ret < 0)
312 return ret;
313
314 if (ftrace_enabled)
315 update_ftrace_function();
316
317 /*
318 * Dynamic ops may be freed, we must make sure that all
319 * callers are done before leaving this function.
320 */
321 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
322 synchronize_sched();
323
324 return 0;
325}
326
327static void ftrace_update_pid_func(void)
328{
329 /* Only do something if we are tracing something */
330 if (ftrace_trace_function == ftrace_stub)
331 return;
332
333 update_ftrace_function();
334}
335
336#ifdef CONFIG_FUNCTION_PROFILER
337struct ftrace_profile {
338 struct hlist_node node;
339 unsigned long ip;
340 unsigned long counter;
341#ifdef CONFIG_FUNCTION_GRAPH_TRACER
342 unsigned long long time;
343 unsigned long long time_squared;
344#endif
345};
346
347struct ftrace_profile_page {
348 struct ftrace_profile_page *next;
349 unsigned long index;
350 struct ftrace_profile records[];
351};
352
353struct ftrace_profile_stat {
354 atomic_t disabled;
355 struct hlist_head *hash;
356 struct ftrace_profile_page *pages;
357 struct ftrace_profile_page *start;
358 struct tracer_stat stat;
359};
360
361#define PROFILE_RECORDS_SIZE \
362 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
363
364#define PROFILES_PER_PAGE \
365 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
366
367static int ftrace_profile_bits __read_mostly;
368static int ftrace_profile_enabled __read_mostly;
369
370/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
371static DEFINE_MUTEX(ftrace_profile_lock);
372
373static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
374
375#define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
376
377static void *
378function_stat_next(void *v, int idx)
379{
380 struct ftrace_profile *rec = v;
381 struct ftrace_profile_page *pg;
382
383 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
384
385 again:
386 if (idx != 0)
387 rec++;
388
389 if ((void *)rec >= (void *)&pg->records[pg->index]) {
390 pg = pg->next;
391 if (!pg)
392 return NULL;
393 rec = &pg->records[0];
394 if (!rec->counter)
395 goto again;
396 }
397
398 return rec;
399}
400
401static void *function_stat_start(struct tracer_stat *trace)
402{
403 struct ftrace_profile_stat *stat =
404 container_of(trace, struct ftrace_profile_stat, stat);
405
406 if (!stat || !stat->start)
407 return NULL;
408
409 return function_stat_next(&stat->start->records[0], 0);
410}
411
412#ifdef CONFIG_FUNCTION_GRAPH_TRACER
413/* function graph compares on total time */
414static int function_stat_cmp(void *p1, void *p2)
415{
416 struct ftrace_profile *a = p1;
417 struct ftrace_profile *b = p2;
418
419 if (a->time < b->time)
420 return -1;
421 if (a->time > b->time)
422 return 1;
423 else
424 return 0;
425}
426#else
427/* not function graph compares against hits */
428static int function_stat_cmp(void *p1, void *p2)
429{
430 struct ftrace_profile *a = p1;
431 struct ftrace_profile *b = p2;
432
433 if (a->counter < b->counter)
434 return -1;
435 if (a->counter > b->counter)
436 return 1;
437 else
438 return 0;
439}
440#endif
441
442static int function_stat_headers(struct seq_file *m)
443{
444#ifdef CONFIG_FUNCTION_GRAPH_TRACER
445 seq_printf(m, " Function "
446 "Hit Time Avg s^2\n"
447 " -------- "
448 "--- ---- --- ---\n");
449#else
450 seq_printf(m, " Function Hit\n"
451 " -------- ---\n");
452#endif
453 return 0;
454}
455
456static int function_stat_show(struct seq_file *m, void *v)
457{
458 struct ftrace_profile *rec = v;
459 char str[KSYM_SYMBOL_LEN];
460 int ret = 0;
461#ifdef CONFIG_FUNCTION_GRAPH_TRACER
462 static struct trace_seq s;
463 unsigned long long avg;
464 unsigned long long stddev;
465#endif
466 mutex_lock(&ftrace_profile_lock);
467
468 /* we raced with function_profile_reset() */
469 if (unlikely(rec->counter == 0)) {
470 ret = -EBUSY;
471 goto out;
472 }
473
474 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
475 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
476
477#ifdef CONFIG_FUNCTION_GRAPH_TRACER
478 seq_printf(m, " ");
479 avg = rec->time;
480 do_div(avg, rec->counter);
481
482 /* Sample standard deviation (s^2) */
483 if (rec->counter <= 1)
484 stddev = 0;
485 else {
486 stddev = rec->time_squared - rec->counter * avg * avg;
487 /*
488 * Divide only 1000 for ns^2 -> us^2 conversion.
489 * trace_print_graph_duration will divide 1000 again.
490 */
491 do_div(stddev, (rec->counter - 1) * 1000);
492 }
493
494 trace_seq_init(&s);
495 trace_print_graph_duration(rec->time, &s);
496 trace_seq_puts(&s, " ");
497 trace_print_graph_duration(avg, &s);
498 trace_seq_puts(&s, " ");
499 trace_print_graph_duration(stddev, &s);
500 trace_print_seq(m, &s);
501#endif
502 seq_putc(m, '\n');
503out:
504 mutex_unlock(&ftrace_profile_lock);
505
506 return ret;
507}
508
509static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
510{
511 struct ftrace_profile_page *pg;
512
513 pg = stat->pages = stat->start;
514
515 while (pg) {
516 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
517 pg->index = 0;
518 pg = pg->next;
519 }
520
521 memset(stat->hash, 0,
522 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
523}
524
525int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
526{
527 struct ftrace_profile_page *pg;
528 int functions;
529 int pages;
530 int i;
531
532 /* If we already allocated, do nothing */
533 if (stat->pages)
534 return 0;
535
536 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
537 if (!stat->pages)
538 return -ENOMEM;
539
540#ifdef CONFIG_DYNAMIC_FTRACE
541 functions = ftrace_update_tot_cnt;
542#else
543 /*
544 * We do not know the number of functions that exist because
545 * dynamic tracing is what counts them. With past experience
546 * we have around 20K functions. That should be more than enough.
547 * It is highly unlikely we will execute every function in
548 * the kernel.
549 */
550 functions = 20000;
551#endif
552
553 pg = stat->start = stat->pages;
554
555 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
556
557 for (i = 0; i < pages; i++) {
558 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
559 if (!pg->next)
560 goto out_free;
561 pg = pg->next;
562 }
563
564 return 0;
565
566 out_free:
567 pg = stat->start;
568 while (pg) {
569 unsigned long tmp = (unsigned long)pg;
570
571 pg = pg->next;
572 free_page(tmp);
573 }
574
575 free_page((unsigned long)stat->pages);
576 stat->pages = NULL;
577 stat->start = NULL;
578
579 return -ENOMEM;
580}
581
582static int ftrace_profile_init_cpu(int cpu)
583{
584 struct ftrace_profile_stat *stat;
585 int size;
586
587 stat = &per_cpu(ftrace_profile_stats, cpu);
588
589 if (stat->hash) {
590 /* If the profile is already created, simply reset it */
591 ftrace_profile_reset(stat);
592 return 0;
593 }
594
595 /*
596 * We are profiling all functions, but usually only a few thousand
597 * functions are hit. We'll make a hash of 1024 items.
598 */
599 size = FTRACE_PROFILE_HASH_SIZE;
600
601 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
602
603 if (!stat->hash)
604 return -ENOMEM;
605
606 if (!ftrace_profile_bits) {
607 size--;
608
609 for (; size; size >>= 1)
610 ftrace_profile_bits++;
611 }
612
613 /* Preallocate the function profiling pages */
614 if (ftrace_profile_pages_init(stat) < 0) {
615 kfree(stat->hash);
616 stat->hash = NULL;
617 return -ENOMEM;
618 }
619
620 return 0;
621}
622
623static int ftrace_profile_init(void)
624{
625 int cpu;
626 int ret = 0;
627
628 for_each_online_cpu(cpu) {
629 ret = ftrace_profile_init_cpu(cpu);
630 if (ret)
631 break;
632 }
633
634 return ret;
635}
636
637/* interrupts must be disabled */
638static struct ftrace_profile *
639ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
640{
641 struct ftrace_profile *rec;
642 struct hlist_head *hhd;
643 struct hlist_node *n;
644 unsigned long key;
645
646 key = hash_long(ip, ftrace_profile_bits);
647 hhd = &stat->hash[key];
648
649 if (hlist_empty(hhd))
650 return NULL;
651
652 hlist_for_each_entry_rcu(rec, n, hhd, node) {
653 if (rec->ip == ip)
654 return rec;
655 }
656
657 return NULL;
658}
659
660static void ftrace_add_profile(struct ftrace_profile_stat *stat,
661 struct ftrace_profile *rec)
662{
663 unsigned long key;
664
665 key = hash_long(rec->ip, ftrace_profile_bits);
666 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
667}
668
669/*
670 * The memory is already allocated, this simply finds a new record to use.
671 */
672static struct ftrace_profile *
673ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
674{
675 struct ftrace_profile *rec = NULL;
676
677 /* prevent recursion (from NMIs) */
678 if (atomic_inc_return(&stat->disabled) != 1)
679 goto out;
680
681 /*
682 * Try to find the function again since an NMI
683 * could have added it
684 */
685 rec = ftrace_find_profiled_func(stat, ip);
686 if (rec)
687 goto out;
688
689 if (stat->pages->index == PROFILES_PER_PAGE) {
690 if (!stat->pages->next)
691 goto out;
692 stat->pages = stat->pages->next;
693 }
694
695 rec = &stat->pages->records[stat->pages->index++];
696 rec->ip = ip;
697 ftrace_add_profile(stat, rec);
698
699 out:
700 atomic_dec(&stat->disabled);
701
702 return rec;
703}
704
705static void
706function_profile_call(unsigned long ip, unsigned long parent_ip)
707{
708 struct ftrace_profile_stat *stat;
709 struct ftrace_profile *rec;
710 unsigned long flags;
711
712 if (!ftrace_profile_enabled)
713 return;
714
715 local_irq_save(flags);
716
717 stat = &__get_cpu_var(ftrace_profile_stats);
718 if (!stat->hash || !ftrace_profile_enabled)
719 goto out;
720
721 rec = ftrace_find_profiled_func(stat, ip);
722 if (!rec) {
723 rec = ftrace_profile_alloc(stat, ip);
724 if (!rec)
725 goto out;
726 }
727
728 rec->counter++;
729 out:
730 local_irq_restore(flags);
731}
732
733#ifdef CONFIG_FUNCTION_GRAPH_TRACER
734static int profile_graph_entry(struct ftrace_graph_ent *trace)
735{
736 function_profile_call(trace->func, 0);
737 return 1;
738}
739
740static void profile_graph_return(struct ftrace_graph_ret *trace)
741{
742 struct ftrace_profile_stat *stat;
743 unsigned long long calltime;
744 struct ftrace_profile *rec;
745 unsigned long flags;
746
747 local_irq_save(flags);
748 stat = &__get_cpu_var(ftrace_profile_stats);
749 if (!stat->hash || !ftrace_profile_enabled)
750 goto out;
751
752 /* If the calltime was zero'd ignore it */
753 if (!trace->calltime)
754 goto out;
755
756 calltime = trace->rettime - trace->calltime;
757
758 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
759 int index;
760
761 index = trace->depth;
762
763 /* Append this call time to the parent time to subtract */
764 if (index)
765 current->ret_stack[index - 1].subtime += calltime;
766
767 if (current->ret_stack[index].subtime < calltime)
768 calltime -= current->ret_stack[index].subtime;
769 else
770 calltime = 0;
771 }
772
773 rec = ftrace_find_profiled_func(stat, trace->func);
774 if (rec) {
775 rec->time += calltime;
776 rec->time_squared += calltime * calltime;
777 }
778
779 out:
780 local_irq_restore(flags);
781}
782
783static int register_ftrace_profiler(void)
784{
785 return register_ftrace_graph(&profile_graph_return,
786 &profile_graph_entry);
787}
788
789static void unregister_ftrace_profiler(void)
790{
791 unregister_ftrace_graph();
792}
793#else
794static struct ftrace_ops ftrace_profile_ops __read_mostly = {
795 .func = function_profile_call,
796};
797
798static int register_ftrace_profiler(void)
799{
800 return register_ftrace_function(&ftrace_profile_ops);
801}
802
803static void unregister_ftrace_profiler(void)
804{
805 unregister_ftrace_function(&ftrace_profile_ops);
806}
807#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
808
809static ssize_t
810ftrace_profile_write(struct file *filp, const char __user *ubuf,
811 size_t cnt, loff_t *ppos)
812{
813 unsigned long val;
814 int ret;
815
816 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
817 if (ret)
818 return ret;
819
820 val = !!val;
821
822 mutex_lock(&ftrace_profile_lock);
823 if (ftrace_profile_enabled ^ val) {
824 if (val) {
825 ret = ftrace_profile_init();
826 if (ret < 0) {
827 cnt = ret;
828 goto out;
829 }
830
831 ret = register_ftrace_profiler();
832 if (ret < 0) {
833 cnt = ret;
834 goto out;
835 }
836 ftrace_profile_enabled = 1;
837 } else {
838 ftrace_profile_enabled = 0;
839 /*
840 * unregister_ftrace_profiler calls stop_machine
841 * so this acts like an synchronize_sched.
842 */
843 unregister_ftrace_profiler();
844 }
845 }
846 out:
847 mutex_unlock(&ftrace_profile_lock);
848
849 *ppos += cnt;
850
851 return cnt;
852}
853
854static ssize_t
855ftrace_profile_read(struct file *filp, char __user *ubuf,
856 size_t cnt, loff_t *ppos)
857{
858 char buf[64]; /* big enough to hold a number */
859 int r;
860
861 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
862 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
863}
864
865static const struct file_operations ftrace_profile_fops = {
866 .open = tracing_open_generic,
867 .read = ftrace_profile_read,
868 .write = ftrace_profile_write,
869 .llseek = default_llseek,
870};
871
872/* used to initialize the real stat files */
873static struct tracer_stat function_stats __initdata = {
874 .name = "functions",
875 .stat_start = function_stat_start,
876 .stat_next = function_stat_next,
877 .stat_cmp = function_stat_cmp,
878 .stat_headers = function_stat_headers,
879 .stat_show = function_stat_show
880};
881
882static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
883{
884 struct ftrace_profile_stat *stat;
885 struct dentry *entry;
886 char *name;
887 int ret;
888 int cpu;
889
890 for_each_possible_cpu(cpu) {
891 stat = &per_cpu(ftrace_profile_stats, cpu);
892
893 /* allocate enough for function name + cpu number */
894 name = kmalloc(32, GFP_KERNEL);
895 if (!name) {
896 /*
897 * The files created are permanent, if something happens
898 * we still do not free memory.
899 */
900 WARN(1,
901 "Could not allocate stat file for cpu %d\n",
902 cpu);
903 return;
904 }
905 stat->stat = function_stats;
906 snprintf(name, 32, "function%d", cpu);
907 stat->stat.name = name;
908 ret = register_stat_tracer(&stat->stat);
909 if (ret) {
910 WARN(1,
911 "Could not register function stat for cpu %d\n",
912 cpu);
913 kfree(name);
914 return;
915 }
916 }
917
918 entry = debugfs_create_file("function_profile_enabled", 0644,
919 d_tracer, NULL, &ftrace_profile_fops);
920 if (!entry)
921 pr_warning("Could not create debugfs "
922 "'function_profile_enabled' entry\n");
923}
924
925#else /* CONFIG_FUNCTION_PROFILER */
926static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
927{
928}
929#endif /* CONFIG_FUNCTION_PROFILER */
930
931static struct pid * const ftrace_swapper_pid = &init_struct_pid;
932
933#ifdef CONFIG_DYNAMIC_FTRACE
934
935#ifndef CONFIG_FTRACE_MCOUNT_RECORD
936# error Dynamic ftrace depends on MCOUNT_RECORD
937#endif
938
939static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
940
941struct ftrace_func_probe {
942 struct hlist_node node;
943 struct ftrace_probe_ops *ops;
944 unsigned long flags;
945 unsigned long ip;
946 void *data;
947 struct rcu_head rcu;
948};
949
950enum {
951 FTRACE_ENABLE_CALLS = (1 << 0),
952 FTRACE_DISABLE_CALLS = (1 << 1),
953 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
954 FTRACE_START_FUNC_RET = (1 << 3),
955 FTRACE_STOP_FUNC_RET = (1 << 4),
956};
957struct ftrace_func_entry {
958 struct hlist_node hlist;
959 unsigned long ip;
960};
961
962struct ftrace_hash {
963 unsigned long size_bits;
964 struct hlist_head *buckets;
965 unsigned long count;
966 struct rcu_head rcu;
967};
968
969/*
970 * We make these constant because no one should touch them,
971 * but they are used as the default "empty hash", to avoid allocating
972 * it all the time. These are in a read only section such that if
973 * anyone does try to modify it, it will cause an exception.
974 */
975static const struct hlist_head empty_buckets[1];
976static const struct ftrace_hash empty_hash = {
977 .buckets = (struct hlist_head *)empty_buckets,
978};
979#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
980
981static struct ftrace_ops global_ops = {
982 .func = ftrace_stub,
983 .notrace_hash = EMPTY_HASH,
984 .filter_hash = EMPTY_HASH,
985};
986
987static struct dyn_ftrace *ftrace_new_addrs;
988
989static DEFINE_MUTEX(ftrace_regex_lock);
990
991struct ftrace_page {
992 struct ftrace_page *next;
993 int index;
994 struct dyn_ftrace records[];
995};
996
997#define ENTRIES_PER_PAGE \
998 ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
999
1000/* estimate from running different kernels */
1001#define NR_TO_INIT 10000
1002
1003static struct ftrace_page *ftrace_pages_start;
1004static struct ftrace_page *ftrace_pages;
1005
1006static struct dyn_ftrace *ftrace_free_records;
1007
1008static struct ftrace_func_entry *
1009ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1010{
1011 unsigned long key;
1012 struct ftrace_func_entry *entry;
1013 struct hlist_head *hhd;
1014 struct hlist_node *n;
1015
1016 if (!hash->count)
1017 return NULL;
1018
1019 if (hash->size_bits > 0)
1020 key = hash_long(ip, hash->size_bits);
1021 else
1022 key = 0;
1023
1024 hhd = &hash->buckets[key];
1025
1026 hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
1027 if (entry->ip == ip)
1028 return entry;
1029 }
1030 return NULL;
1031}
1032
1033static void __add_hash_entry(struct ftrace_hash *hash,
1034 struct ftrace_func_entry *entry)
1035{
1036 struct hlist_head *hhd;
1037 unsigned long key;
1038
1039 if (hash->size_bits)
1040 key = hash_long(entry->ip, hash->size_bits);
1041 else
1042 key = 0;
1043
1044 hhd = &hash->buckets[key];
1045 hlist_add_head(&entry->hlist, hhd);
1046 hash->count++;
1047}
1048
1049static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1050{
1051 struct ftrace_func_entry *entry;
1052
1053 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1054 if (!entry)
1055 return -ENOMEM;
1056
1057 entry->ip = ip;
1058 __add_hash_entry(hash, entry);
1059
1060 return 0;
1061}
1062
1063static void
1064free_hash_entry(struct ftrace_hash *hash,
1065 struct ftrace_func_entry *entry)
1066{
1067 hlist_del(&entry->hlist);
1068 kfree(entry);
1069 hash->count--;
1070}
1071
1072static void
1073remove_hash_entry(struct ftrace_hash *hash,
1074 struct ftrace_func_entry *entry)
1075{
1076 hlist_del(&entry->hlist);
1077 hash->count--;
1078}
1079
1080static void ftrace_hash_clear(struct ftrace_hash *hash)
1081{
1082 struct hlist_head *hhd;
1083 struct hlist_node *tp, *tn;
1084 struct ftrace_func_entry *entry;
1085 int size = 1 << hash->size_bits;
1086 int i;
1087
1088 if (!hash->count)
1089 return;
1090
1091 for (i = 0; i < size; i++) {
1092 hhd = &hash->buckets[i];
1093 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
1094 free_hash_entry(hash, entry);
1095 }
1096 FTRACE_WARN_ON(hash->count);
1097}
1098
1099static void free_ftrace_hash(struct ftrace_hash *hash)
1100{
1101 if (!hash || hash == EMPTY_HASH)
1102 return;
1103 ftrace_hash_clear(hash);
1104 kfree(hash->buckets);
1105 kfree(hash);
1106}
1107
1108static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1109{
1110 struct ftrace_hash *hash;
1111
1112 hash = container_of(rcu, struct ftrace_hash, rcu);
1113 free_ftrace_hash(hash);
1114}
1115
1116static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1117{
1118 if (!hash || hash == EMPTY_HASH)
1119 return;
1120 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1121}
1122
1123static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1124{
1125 struct ftrace_hash *hash;
1126 int size;
1127
1128 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1129 if (!hash)
1130 return NULL;
1131
1132 size = 1 << size_bits;
1133 hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL);
1134
1135 if (!hash->buckets) {
1136 kfree(hash);
1137 return NULL;
1138 }
1139
1140 hash->size_bits = size_bits;
1141
1142 return hash;
1143}
1144
1145static struct ftrace_hash *
1146alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1147{
1148 struct ftrace_func_entry *entry;
1149 struct ftrace_hash *new_hash;
1150 struct hlist_node *tp;
1151 int size;
1152 int ret;
1153 int i;
1154
1155 new_hash = alloc_ftrace_hash(size_bits);
1156 if (!new_hash)
1157 return NULL;
1158
1159 /* Empty hash? */
1160 if (!hash || !hash->count)
1161 return new_hash;
1162
1163 size = 1 << hash->size_bits;
1164 for (i = 0; i < size; i++) {
1165 hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
1166 ret = add_hash_entry(new_hash, entry->ip);
1167 if (ret < 0)
1168 goto free_hash;
1169 }
1170 }
1171
1172 FTRACE_WARN_ON(new_hash->count != hash->count);
1173
1174 return new_hash;
1175
1176 free_hash:
1177 free_ftrace_hash(new_hash);
1178 return NULL;
1179}
1180
1181static void
1182ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
1183static void
1184ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
1185
1186static int
1187ftrace_hash_move(struct ftrace_ops *ops, int enable,
1188 struct ftrace_hash **dst, struct ftrace_hash *src)
1189{
1190 struct ftrace_func_entry *entry;
1191 struct hlist_node *tp, *tn;
1192 struct hlist_head *hhd;
1193 struct ftrace_hash *old_hash;
1194 struct ftrace_hash *new_hash;
1195 unsigned long key;
1196 int size = src->count;
1197 int bits = 0;
1198 int ret;
1199 int i;
1200
1201 /*
1202 * Remove the current set, update the hash and add
1203 * them back.
1204 */
1205 ftrace_hash_rec_disable(ops, enable);
1206
1207 /*
1208 * If the new source is empty, just free dst and assign it
1209 * the empty_hash.
1210 */
1211 if (!src->count) {
1212 free_ftrace_hash_rcu(*dst);
1213 rcu_assign_pointer(*dst, EMPTY_HASH);
1214 return 0;
1215 }
1216
1217 /*
1218 * Make the hash size about 1/2 the # found
1219 */
1220 for (size /= 2; size; size >>= 1)
1221 bits++;
1222
1223 /* Don't allocate too much */
1224 if (bits > FTRACE_HASH_MAX_BITS)
1225 bits = FTRACE_HASH_MAX_BITS;
1226
1227 ret = -ENOMEM;
1228 new_hash = alloc_ftrace_hash(bits);
1229 if (!new_hash)
1230 goto out;
1231
1232 size = 1 << src->size_bits;
1233 for (i = 0; i < size; i++) {
1234 hhd = &src->buckets[i];
1235 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
1236 if (bits > 0)
1237 key = hash_long(entry->ip, bits);
1238 else
1239 key = 0;
1240 remove_hash_entry(src, entry);
1241 __add_hash_entry(new_hash, entry);
1242 }
1243 }
1244
1245 old_hash = *dst;
1246 rcu_assign_pointer(*dst, new_hash);
1247 free_ftrace_hash_rcu(old_hash);
1248
1249 ret = 0;
1250 out:
1251 /*
1252 * Enable regardless of ret:
1253 * On success, we enable the new hash.
1254 * On failure, we re-enable the original hash.
1255 */
1256 ftrace_hash_rec_enable(ops, enable);
1257
1258 return ret;
1259}
1260
1261/*
1262 * Test the hashes for this ops to see if we want to call
1263 * the ops->func or not.
1264 *
1265 * It's a match if the ip is in the ops->filter_hash or
1266 * the filter_hash does not exist or is empty,
1267 * AND
1268 * the ip is not in the ops->notrace_hash.
1269 *
1270 * This needs to be called with preemption disabled as
1271 * the hashes are freed with call_rcu_sched().
1272 */
1273static int
1274ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
1275{
1276 struct ftrace_hash *filter_hash;
1277 struct ftrace_hash *notrace_hash;
1278 int ret;
1279
1280 filter_hash = rcu_dereference_raw(ops->filter_hash);
1281 notrace_hash = rcu_dereference_raw(ops->notrace_hash);
1282
1283 if ((!filter_hash || !filter_hash->count ||
1284 ftrace_lookup_ip(filter_hash, ip)) &&
1285 (!notrace_hash || !notrace_hash->count ||
1286 !ftrace_lookup_ip(notrace_hash, ip)))
1287 ret = 1;
1288 else
1289 ret = 0;
1290
1291 return ret;
1292}
1293
1294/*
1295 * This is a double for. Do not use 'break' to break out of the loop,
1296 * you must use a goto.
1297 */
1298#define do_for_each_ftrace_rec(pg, rec) \
1299 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1300 int _____i; \
1301 for (_____i = 0; _____i < pg->index; _____i++) { \
1302 rec = &pg->records[_____i];
1303
1304#define while_for_each_ftrace_rec() \
1305 } \
1306 }
1307
1308static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1309 int filter_hash,
1310 bool inc)
1311{
1312 struct ftrace_hash *hash;
1313 struct ftrace_hash *other_hash;
1314 struct ftrace_page *pg;
1315 struct dyn_ftrace *rec;
1316 int count = 0;
1317 int all = 0;
1318
1319 /* Only update if the ops has been registered */
1320 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1321 return;
1322
1323 /*
1324 * In the filter_hash case:
1325 * If the count is zero, we update all records.
1326 * Otherwise we just update the items in the hash.
1327 *
1328 * In the notrace_hash case:
1329 * We enable the update in the hash.
1330 * As disabling notrace means enabling the tracing,
1331 * and enabling notrace means disabling, the inc variable
1332 * gets inversed.
1333 */
1334 if (filter_hash) {
1335 hash = ops->filter_hash;
1336 other_hash = ops->notrace_hash;
1337 if (!hash || !hash->count)
1338 all = 1;
1339 } else {
1340 inc = !inc;
1341 hash = ops->notrace_hash;
1342 other_hash = ops->filter_hash;
1343 /*
1344 * If the notrace hash has no items,
1345 * then there's nothing to do.
1346 */
1347 if (hash && !hash->count)
1348 return;
1349 }
1350
1351 do_for_each_ftrace_rec(pg, rec) {
1352 int in_other_hash = 0;
1353 int in_hash = 0;
1354 int match = 0;
1355
1356 if (all) {
1357 /*
1358 * Only the filter_hash affects all records.
1359 * Update if the record is not in the notrace hash.
1360 */
1361 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1362 match = 1;
1363 } else {
1364 in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip);
1365 in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip);
1366
1367 /*
1368 *
1369 */
1370 if (filter_hash && in_hash && !in_other_hash)
1371 match = 1;
1372 else if (!filter_hash && in_hash &&
1373 (in_other_hash || !other_hash->count))
1374 match = 1;
1375 }
1376 if (!match)
1377 continue;
1378
1379 if (inc) {
1380 rec->flags++;
1381 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
1382 return;
1383 } else {
1384 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
1385 return;
1386 rec->flags--;
1387 }
1388 count++;
1389 /* Shortcut, if we handled all records, we are done. */
1390 if (!all && count == hash->count)
1391 return;
1392 } while_for_each_ftrace_rec();
1393}
1394
1395static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1396 int filter_hash)
1397{
1398 __ftrace_hash_rec_update(ops, filter_hash, 0);
1399}
1400
1401static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1402 int filter_hash)
1403{
1404 __ftrace_hash_rec_update(ops, filter_hash, 1);
1405}
1406
1407static void ftrace_free_rec(struct dyn_ftrace *rec)
1408{
1409 rec->freelist = ftrace_free_records;
1410 ftrace_free_records = rec;
1411 rec->flags |= FTRACE_FL_FREE;
1412}
1413
1414static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
1415{
1416 struct dyn_ftrace *rec;
1417
1418 /* First check for freed records */
1419 if (ftrace_free_records) {
1420 rec = ftrace_free_records;
1421
1422 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
1423 FTRACE_WARN_ON_ONCE(1);
1424 ftrace_free_records = NULL;
1425 return NULL;
1426 }
1427
1428 ftrace_free_records = rec->freelist;
1429 memset(rec, 0, sizeof(*rec));
1430 return rec;
1431 }
1432
1433 if (ftrace_pages->index == ENTRIES_PER_PAGE) {
1434 if (!ftrace_pages->next) {
1435 /* allocate another page */
1436 ftrace_pages->next =
1437 (void *)get_zeroed_page(GFP_KERNEL);
1438 if (!ftrace_pages->next)
1439 return NULL;
1440 }
1441 ftrace_pages = ftrace_pages->next;
1442 }
1443
1444 return &ftrace_pages->records[ftrace_pages->index++];
1445}
1446
1447static struct dyn_ftrace *
1448ftrace_record_ip(unsigned long ip)
1449{
1450 struct dyn_ftrace *rec;
1451
1452 if (ftrace_disabled)
1453 return NULL;
1454
1455 rec = ftrace_alloc_dyn_node(ip);
1456 if (!rec)
1457 return NULL;
1458
1459 rec->ip = ip;
1460 rec->newlist = ftrace_new_addrs;
1461 ftrace_new_addrs = rec;
1462
1463 return rec;
1464}
1465
1466static void print_ip_ins(const char *fmt, unsigned char *p)
1467{
1468 int i;
1469
1470 printk(KERN_CONT "%s", fmt);
1471
1472 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1473 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1474}
1475
1476static void ftrace_bug(int failed, unsigned long ip)
1477{
1478 switch (failed) {
1479 case -EFAULT:
1480 FTRACE_WARN_ON_ONCE(1);
1481 pr_info("ftrace faulted on modifying ");
1482 print_ip_sym(ip);
1483 break;
1484 case -EINVAL:
1485 FTRACE_WARN_ON_ONCE(1);
1486 pr_info("ftrace failed to modify ");
1487 print_ip_sym(ip);
1488 print_ip_ins(" actual: ", (unsigned char *)ip);
1489 printk(KERN_CONT "\n");
1490 break;
1491 case -EPERM:
1492 FTRACE_WARN_ON_ONCE(1);
1493 pr_info("ftrace faulted on writing ");
1494 print_ip_sym(ip);
1495 break;
1496 default:
1497 FTRACE_WARN_ON_ONCE(1);
1498 pr_info("ftrace faulted on unknown error ");
1499 print_ip_sym(ip);
1500 }
1501}
1502
1503
1504/* Return 1 if the address range is reserved for ftrace */
1505int ftrace_text_reserved(void *start, void *end)
1506{
1507 struct dyn_ftrace *rec;
1508 struct ftrace_page *pg;
1509
1510 do_for_each_ftrace_rec(pg, rec) {
1511 if (rec->ip <= (unsigned long)end &&
1512 rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start)
1513 return 1;
1514 } while_for_each_ftrace_rec();
1515 return 0;
1516}
1517
1518
1519static int
1520__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1521{
1522 unsigned long ftrace_addr;
1523 unsigned long flag = 0UL;
1524
1525 ftrace_addr = (unsigned long)FTRACE_ADDR;
1526
1527 /*
1528 * If we are enabling tracing:
1529 *
1530 * If the record has a ref count, then we need to enable it
1531 * because someone is using it.
1532 *
1533 * Otherwise we make sure its disabled.
1534 *
1535 * If we are disabling tracing, then disable all records that
1536 * are enabled.
1537 */
1538 if (enable && (rec->flags & ~FTRACE_FL_MASK))
1539 flag = FTRACE_FL_ENABLED;
1540
1541 /* If the state of this record hasn't changed, then do nothing */
1542 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1543 return 0;
1544
1545 if (flag) {
1546 rec->flags |= FTRACE_FL_ENABLED;
1547 return ftrace_make_call(rec, ftrace_addr);
1548 }
1549
1550 rec->flags &= ~FTRACE_FL_ENABLED;
1551 return ftrace_make_nop(NULL, rec, ftrace_addr);
1552}
1553
1554static void ftrace_replace_code(int enable)
1555{
1556 struct dyn_ftrace *rec;
1557 struct ftrace_page *pg;
1558 int failed;
1559
1560 if (unlikely(ftrace_disabled))
1561 return;
1562
1563 do_for_each_ftrace_rec(pg, rec) {
1564 /* Skip over free records */
1565 if (rec->flags & FTRACE_FL_FREE)
1566 continue;
1567
1568 failed = __ftrace_replace_code(rec, enable);
1569 if (failed) {
1570 ftrace_bug(failed, rec->ip);
1571 /* Stop processing */
1572 return;
1573 }
1574 } while_for_each_ftrace_rec();
1575}
1576
1577static int
1578ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1579{
1580 unsigned long ip;
1581 int ret;
1582
1583 ip = rec->ip;
1584
1585 if (unlikely(ftrace_disabled))
1586 return 0;
1587
1588 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1589 if (ret) {
1590 ftrace_bug(ret, ip);
1591 return 0;
1592 }
1593 return 1;
1594}
1595
1596/*
1597 * archs can override this function if they must do something
1598 * before the modifying code is performed.
1599 */
1600int __weak ftrace_arch_code_modify_prepare(void)
1601{
1602 return 0;
1603}
1604
1605/*
1606 * archs can override this function if they must do something
1607 * after the modifying code is performed.
1608 */
1609int __weak ftrace_arch_code_modify_post_process(void)
1610{
1611 return 0;
1612}
1613
1614static int __ftrace_modify_code(void *data)
1615{
1616 int *command = data;
1617
1618 /*
1619 * Do not call function tracer while we update the code.
1620 * We are in stop machine, no worrying about races.
1621 */
1622 function_trace_stop++;
1623
1624 if (*command & FTRACE_ENABLE_CALLS)
1625 ftrace_replace_code(1);
1626 else if (*command & FTRACE_DISABLE_CALLS)
1627 ftrace_replace_code(0);
1628
1629 if (*command & FTRACE_UPDATE_TRACE_FUNC)
1630 ftrace_update_ftrace_func(ftrace_trace_function);
1631
1632 if (*command & FTRACE_START_FUNC_RET)
1633 ftrace_enable_ftrace_graph_caller();
1634 else if (*command & FTRACE_STOP_FUNC_RET)
1635 ftrace_disable_ftrace_graph_caller();
1636
1637#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
1638 /*
1639 * For archs that call ftrace_test_stop_func(), we must
1640 * wait till after we update all the function callers
1641 * before we update the callback. This keeps different
1642 * ops that record different functions from corrupting
1643 * each other.
1644 */
1645 __ftrace_trace_function = __ftrace_trace_function_delay;
1646#endif
1647 function_trace_stop--;
1648
1649 return 0;
1650}
1651
1652static void ftrace_run_update_code(int command)
1653{
1654 int ret;
1655
1656 ret = ftrace_arch_code_modify_prepare();
1657 FTRACE_WARN_ON(ret);
1658 if (ret)
1659 return;
1660
1661 stop_machine(__ftrace_modify_code, &command, NULL);
1662
1663 ret = ftrace_arch_code_modify_post_process();
1664 FTRACE_WARN_ON(ret);
1665}
1666
1667static ftrace_func_t saved_ftrace_func;
1668static int ftrace_start_up;
1669static int global_start_up;
1670
1671static void ftrace_startup_enable(int command)
1672{
1673 if (saved_ftrace_func != ftrace_trace_function) {
1674 saved_ftrace_func = ftrace_trace_function;
1675 command |= FTRACE_UPDATE_TRACE_FUNC;
1676 }
1677
1678 if (!command || !ftrace_enabled)
1679 return;
1680
1681 ftrace_run_update_code(command);
1682}
1683
1684static int ftrace_startup(struct ftrace_ops *ops, int command)
1685{
1686 bool hash_enable = true;
1687
1688 if (unlikely(ftrace_disabled))
1689 return -ENODEV;
1690
1691 ftrace_start_up++;
1692 command |= FTRACE_ENABLE_CALLS;
1693
1694 /* ops marked global share the filter hashes */
1695 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1696 ops = &global_ops;
1697 /* Don't update hash if global is already set */
1698 if (global_start_up)
1699 hash_enable = false;
1700 global_start_up++;
1701 }
1702
1703 ops->flags |= FTRACE_OPS_FL_ENABLED;
1704 if (hash_enable)
1705 ftrace_hash_rec_enable(ops, 1);
1706
1707 ftrace_startup_enable(command);
1708
1709 return 0;
1710}
1711
1712static void ftrace_shutdown(struct ftrace_ops *ops, int command)
1713{
1714 bool hash_disable = true;
1715
1716 if (unlikely(ftrace_disabled))
1717 return;
1718
1719 ftrace_start_up--;
1720 /*
1721 * Just warn in case of unbalance, no need to kill ftrace, it's not
1722 * critical but the ftrace_call callers may be never nopped again after
1723 * further ftrace uses.
1724 */
1725 WARN_ON_ONCE(ftrace_start_up < 0);
1726
1727 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1728 ops = &global_ops;
1729 global_start_up--;
1730 WARN_ON_ONCE(global_start_up < 0);
1731 /* Don't update hash if global still has users */
1732 if (global_start_up) {
1733 WARN_ON_ONCE(!ftrace_start_up);
1734 hash_disable = false;
1735 }
1736 }
1737
1738 if (hash_disable)
1739 ftrace_hash_rec_disable(ops, 1);
1740
1741 if (ops != &global_ops || !global_start_up)
1742 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
1743
1744 if (!ftrace_start_up)
1745 command |= FTRACE_DISABLE_CALLS;
1746
1747 if (saved_ftrace_func != ftrace_trace_function) {
1748 saved_ftrace_func = ftrace_trace_function;
1749 command |= FTRACE_UPDATE_TRACE_FUNC;
1750 }
1751
1752 if (!command || !ftrace_enabled)
1753 return;
1754
1755 ftrace_run_update_code(command);
1756}
1757
1758static void ftrace_startup_sysctl(void)
1759{
1760 if (unlikely(ftrace_disabled))
1761 return;
1762
1763 /* Force update next time */
1764 saved_ftrace_func = NULL;
1765 /* ftrace_start_up is true if we want ftrace running */
1766 if (ftrace_start_up)
1767 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
1768}
1769
1770static void ftrace_shutdown_sysctl(void)
1771{
1772 if (unlikely(ftrace_disabled))
1773 return;
1774
1775 /* ftrace_start_up is true if ftrace is running */
1776 if (ftrace_start_up)
1777 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
1778}
1779
1780static cycle_t ftrace_update_time;
1781static unsigned long ftrace_update_cnt;
1782unsigned long ftrace_update_tot_cnt;
1783
1784static int ops_traces_mod(struct ftrace_ops *ops)
1785{
1786 struct ftrace_hash *hash;
1787
1788 hash = ops->filter_hash;
1789 return !!(!hash || !hash->count);
1790}
1791
1792static int ftrace_update_code(struct module *mod)
1793{
1794 struct dyn_ftrace *p;
1795 cycle_t start, stop;
1796 unsigned long ref = 0;
1797
1798 /*
1799 * When adding a module, we need to check if tracers are
1800 * currently enabled and if they are set to trace all functions.
1801 * If they are, we need to enable the module functions as well
1802 * as update the reference counts for those function records.
1803 */
1804 if (mod) {
1805 struct ftrace_ops *ops;
1806
1807 for (ops = ftrace_ops_list;
1808 ops != &ftrace_list_end; ops = ops->next) {
1809 if (ops->flags & FTRACE_OPS_FL_ENABLED &&
1810 ops_traces_mod(ops))
1811 ref++;
1812 }
1813 }
1814
1815 start = ftrace_now(raw_smp_processor_id());
1816 ftrace_update_cnt = 0;
1817
1818 while (ftrace_new_addrs) {
1819
1820 /* If something went wrong, bail without enabling anything */
1821 if (unlikely(ftrace_disabled))
1822 return -1;
1823
1824 p = ftrace_new_addrs;
1825 ftrace_new_addrs = p->newlist;
1826 p->flags = ref;
1827
1828 /*
1829 * Do the initial record conversion from mcount jump
1830 * to the NOP instructions.
1831 */
1832 if (!ftrace_code_disable(mod, p)) {
1833 ftrace_free_rec(p);
1834 /* Game over */
1835 break;
1836 }
1837
1838 ftrace_update_cnt++;
1839
1840 /*
1841 * If the tracing is enabled, go ahead and enable the record.
1842 *
1843 * The reason not to enable the record immediatelly is the
1844 * inherent check of ftrace_make_nop/ftrace_make_call for
1845 * correct previous instructions. Making first the NOP
1846 * conversion puts the module to the correct state, thus
1847 * passing the ftrace_make_call check.
1848 */
1849 if (ftrace_start_up && ref) {
1850 int failed = __ftrace_replace_code(p, 1);
1851 if (failed) {
1852 ftrace_bug(failed, p->ip);
1853 ftrace_free_rec(p);
1854 }
1855 }
1856 }
1857
1858 stop = ftrace_now(raw_smp_processor_id());
1859 ftrace_update_time = stop - start;
1860 ftrace_update_tot_cnt += ftrace_update_cnt;
1861
1862 return 0;
1863}
1864
1865static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
1866{
1867 struct ftrace_page *pg;
1868 int cnt;
1869 int i;
1870
1871 /* allocate a few pages */
1872 ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
1873 if (!ftrace_pages_start)
1874 return -1;
1875
1876 /*
1877 * Allocate a few more pages.
1878 *
1879 * TODO: have some parser search vmlinux before
1880 * final linking to find all calls to ftrace.
1881 * Then we can:
1882 * a) know how many pages to allocate.
1883 * and/or
1884 * b) set up the table then.
1885 *
1886 * The dynamic code is still necessary for
1887 * modules.
1888 */
1889
1890 pg = ftrace_pages = ftrace_pages_start;
1891
1892 cnt = num_to_init / ENTRIES_PER_PAGE;
1893 pr_info("ftrace: allocating %ld entries in %d pages\n",
1894 num_to_init, cnt + 1);
1895
1896 for (i = 0; i < cnt; i++) {
1897 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
1898
1899 /* If we fail, we'll try later anyway */
1900 if (!pg->next)
1901 break;
1902
1903 pg = pg->next;
1904 }
1905
1906 return 0;
1907}
1908
1909enum {
1910 FTRACE_ITER_FILTER = (1 << 0),
1911 FTRACE_ITER_NOTRACE = (1 << 1),
1912 FTRACE_ITER_PRINTALL = (1 << 2),
1913 FTRACE_ITER_HASH = (1 << 3),
1914 FTRACE_ITER_ENABLED = (1 << 4),
1915};
1916
1917#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
1918
1919struct ftrace_iterator {
1920 loff_t pos;
1921 loff_t func_pos;
1922 struct ftrace_page *pg;
1923 struct dyn_ftrace *func;
1924 struct ftrace_func_probe *probe;
1925 struct trace_parser parser;
1926 struct ftrace_hash *hash;
1927 struct ftrace_ops *ops;
1928 int hidx;
1929 int idx;
1930 unsigned flags;
1931};
1932
1933static void *
1934t_hash_next(struct seq_file *m, loff_t *pos)
1935{
1936 struct ftrace_iterator *iter = m->private;
1937 struct hlist_node *hnd = NULL;
1938 struct hlist_head *hhd;
1939
1940 (*pos)++;
1941 iter->pos = *pos;
1942
1943 if (iter->probe)
1944 hnd = &iter->probe->node;
1945 retry:
1946 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
1947 return NULL;
1948
1949 hhd = &ftrace_func_hash[iter->hidx];
1950
1951 if (hlist_empty(hhd)) {
1952 iter->hidx++;
1953 hnd = NULL;
1954 goto retry;
1955 }
1956
1957 if (!hnd)
1958 hnd = hhd->first;
1959 else {
1960 hnd = hnd->next;
1961 if (!hnd) {
1962 iter->hidx++;
1963 goto retry;
1964 }
1965 }
1966
1967 if (WARN_ON_ONCE(!hnd))
1968 return NULL;
1969
1970 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
1971
1972 return iter;
1973}
1974
1975static void *t_hash_start(struct seq_file *m, loff_t *pos)
1976{
1977 struct ftrace_iterator *iter = m->private;
1978 void *p = NULL;
1979 loff_t l;
1980
1981 if (iter->func_pos > *pos)
1982 return NULL;
1983
1984 iter->hidx = 0;
1985 for (l = 0; l <= (*pos - iter->func_pos); ) {
1986 p = t_hash_next(m, &l);
1987 if (!p)
1988 break;
1989 }
1990 if (!p)
1991 return NULL;
1992
1993 /* Only set this if we have an item */
1994 iter->flags |= FTRACE_ITER_HASH;
1995
1996 return iter;
1997}
1998
1999static int
2000t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
2001{
2002 struct ftrace_func_probe *rec;
2003
2004 rec = iter->probe;
2005 if (WARN_ON_ONCE(!rec))
2006 return -EIO;
2007
2008 if (rec->ops->print)
2009 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
2010
2011 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
2012
2013 if (rec->data)
2014 seq_printf(m, ":%p", rec->data);
2015 seq_putc(m, '\n');
2016
2017 return 0;
2018}
2019
2020static void *
2021t_next(struct seq_file *m, void *v, loff_t *pos)
2022{
2023 struct ftrace_iterator *iter = m->private;
2024 struct ftrace_ops *ops = &global_ops;
2025 struct dyn_ftrace *rec = NULL;
2026
2027 if (unlikely(ftrace_disabled))
2028 return NULL;
2029
2030 if (iter->flags & FTRACE_ITER_HASH)
2031 return t_hash_next(m, pos);
2032
2033 (*pos)++;
2034 iter->pos = iter->func_pos = *pos;
2035
2036 if (iter->flags & FTRACE_ITER_PRINTALL)
2037 return t_hash_start(m, pos);
2038
2039 retry:
2040 if (iter->idx >= iter->pg->index) {
2041 if (iter->pg->next) {
2042 iter->pg = iter->pg->next;
2043 iter->idx = 0;
2044 goto retry;
2045 }
2046 } else {
2047 rec = &iter->pg->records[iter->idx++];
2048 if ((rec->flags & FTRACE_FL_FREE) ||
2049
2050 ((iter->flags & FTRACE_ITER_FILTER) &&
2051 !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
2052
2053 ((iter->flags & FTRACE_ITER_NOTRACE) &&
2054 !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
2055
2056 ((iter->flags & FTRACE_ITER_ENABLED) &&
2057 !(rec->flags & ~FTRACE_FL_MASK))) {
2058
2059 rec = NULL;
2060 goto retry;
2061 }
2062 }
2063
2064 if (!rec)
2065 return t_hash_start(m, pos);
2066
2067 iter->func = rec;
2068
2069 return iter;
2070}
2071
2072static void reset_iter_read(struct ftrace_iterator *iter)
2073{
2074 iter->pos = 0;
2075 iter->func_pos = 0;
2076 iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH);
2077}
2078
2079static void *t_start(struct seq_file *m, loff_t *pos)
2080{
2081 struct ftrace_iterator *iter = m->private;
2082 struct ftrace_ops *ops = &global_ops;
2083 void *p = NULL;
2084 loff_t l;
2085
2086 mutex_lock(&ftrace_lock);
2087
2088 if (unlikely(ftrace_disabled))
2089 return NULL;
2090
2091 /*
2092 * If an lseek was done, then reset and start from beginning.
2093 */
2094 if (*pos < iter->pos)
2095 reset_iter_read(iter);
2096
2097 /*
2098 * For set_ftrace_filter reading, if we have the filter
2099 * off, we can short cut and just print out that all
2100 * functions are enabled.
2101 */
2102 if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) {
2103 if (*pos > 0)
2104 return t_hash_start(m, pos);
2105 iter->flags |= FTRACE_ITER_PRINTALL;
2106 /* reset in case of seek/pread */
2107 iter->flags &= ~FTRACE_ITER_HASH;
2108 return iter;
2109 }
2110
2111 if (iter->flags & FTRACE_ITER_HASH)
2112 return t_hash_start(m, pos);
2113
2114 /*
2115 * Unfortunately, we need to restart at ftrace_pages_start
2116 * every time we let go of the ftrace_mutex. This is because
2117 * those pointers can change without the lock.
2118 */
2119 iter->pg = ftrace_pages_start;
2120 iter->idx = 0;
2121 for (l = 0; l <= *pos; ) {
2122 p = t_next(m, p, &l);
2123 if (!p)
2124 break;
2125 }
2126
2127 if (!p) {
2128 if (iter->flags & FTRACE_ITER_FILTER)
2129 return t_hash_start(m, pos);
2130
2131 return NULL;
2132 }
2133
2134 return iter;
2135}
2136
2137static void t_stop(struct seq_file *m, void *p)
2138{
2139 mutex_unlock(&ftrace_lock);
2140}
2141
2142static int t_show(struct seq_file *m, void *v)
2143{
2144 struct ftrace_iterator *iter = m->private;
2145 struct dyn_ftrace *rec;
2146
2147 if (iter->flags & FTRACE_ITER_HASH)
2148 return t_hash_show(m, iter);
2149
2150 if (iter->flags & FTRACE_ITER_PRINTALL) {
2151 seq_printf(m, "#### all functions enabled ####\n");
2152 return 0;
2153 }
2154
2155 rec = iter->func;
2156
2157 if (!rec)
2158 return 0;
2159
2160 seq_printf(m, "%ps", (void *)rec->ip);
2161 if (iter->flags & FTRACE_ITER_ENABLED)
2162 seq_printf(m, " (%ld)",
2163 rec->flags & ~FTRACE_FL_MASK);
2164 seq_printf(m, "\n");
2165
2166 return 0;
2167}
2168
2169static const struct seq_operations show_ftrace_seq_ops = {
2170 .start = t_start,
2171 .next = t_next,
2172 .stop = t_stop,
2173 .show = t_show,
2174};
2175
2176static int
2177ftrace_avail_open(struct inode *inode, struct file *file)
2178{
2179 struct ftrace_iterator *iter;
2180 int ret;
2181
2182 if (unlikely(ftrace_disabled))
2183 return -ENODEV;
2184
2185 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2186 if (!iter)
2187 return -ENOMEM;
2188
2189 iter->pg = ftrace_pages_start;
2190
2191 ret = seq_open(file, &show_ftrace_seq_ops);
2192 if (!ret) {
2193 struct seq_file *m = file->private_data;
2194
2195 m->private = iter;
2196 } else {
2197 kfree(iter);
2198 }
2199
2200 return ret;
2201}
2202
2203static int
2204ftrace_enabled_open(struct inode *inode, struct file *file)
2205{
2206 struct ftrace_iterator *iter;
2207 int ret;
2208
2209 if (unlikely(ftrace_disabled))
2210 return -ENODEV;
2211
2212 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2213 if (!iter)
2214 return -ENOMEM;
2215
2216 iter->pg = ftrace_pages_start;
2217 iter->flags = FTRACE_ITER_ENABLED;
2218
2219 ret = seq_open(file, &show_ftrace_seq_ops);
2220 if (!ret) {
2221 struct seq_file *m = file->private_data;
2222
2223 m->private = iter;
2224 } else {
2225 kfree(iter);
2226 }
2227
2228 return ret;
2229}
2230
2231static void ftrace_filter_reset(struct ftrace_hash *hash)
2232{
2233 mutex_lock(&ftrace_lock);
2234 ftrace_hash_clear(hash);
2235 mutex_unlock(&ftrace_lock);
2236}
2237
2238static int
2239ftrace_regex_open(struct ftrace_ops *ops, int flag,
2240 struct inode *inode, struct file *file)
2241{
2242 struct ftrace_iterator *iter;
2243 struct ftrace_hash *hash;
2244 int ret = 0;
2245
2246 if (unlikely(ftrace_disabled))
2247 return -ENODEV;
2248
2249 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2250 if (!iter)
2251 return -ENOMEM;
2252
2253 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
2254 kfree(iter);
2255 return -ENOMEM;
2256 }
2257
2258 if (flag & FTRACE_ITER_NOTRACE)
2259 hash = ops->notrace_hash;
2260 else
2261 hash = ops->filter_hash;
2262
2263 iter->ops = ops;
2264 iter->flags = flag;
2265
2266 if (file->f_mode & FMODE_WRITE) {
2267 mutex_lock(&ftrace_lock);
2268 iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
2269 mutex_unlock(&ftrace_lock);
2270
2271 if (!iter->hash) {
2272 trace_parser_put(&iter->parser);
2273 kfree(iter);
2274 return -ENOMEM;
2275 }
2276 }
2277
2278 mutex_lock(&ftrace_regex_lock);
2279
2280 if ((file->f_mode & FMODE_WRITE) &&
2281 (file->f_flags & O_TRUNC))
2282 ftrace_filter_reset(iter->hash);
2283
2284 if (file->f_mode & FMODE_READ) {
2285 iter->pg = ftrace_pages_start;
2286
2287 ret = seq_open(file, &show_ftrace_seq_ops);
2288 if (!ret) {
2289 struct seq_file *m = file->private_data;
2290 m->private = iter;
2291 } else {
2292 /* Failed */
2293 free_ftrace_hash(iter->hash);
2294 trace_parser_put(&iter->parser);
2295 kfree(iter);
2296 }
2297 } else
2298 file->private_data = iter;
2299 mutex_unlock(&ftrace_regex_lock);
2300
2301 return ret;
2302}
2303
2304static int
2305ftrace_filter_open(struct inode *inode, struct file *file)
2306{
2307 return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER,
2308 inode, file);
2309}
2310
2311static int
2312ftrace_notrace_open(struct inode *inode, struct file *file)
2313{
2314 return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
2315 inode, file);
2316}
2317
2318static loff_t
2319ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
2320{
2321 loff_t ret;
2322
2323 if (file->f_mode & FMODE_READ)
2324 ret = seq_lseek(file, offset, origin);
2325 else
2326 file->f_pos = ret = 1;
2327
2328 return ret;
2329}
2330
2331static int ftrace_match(char *str, char *regex, int len, int type)
2332{
2333 int matched = 0;
2334 int slen;
2335
2336 switch (type) {
2337 case MATCH_FULL:
2338 if (strcmp(str, regex) == 0)
2339 matched = 1;
2340 break;
2341 case MATCH_FRONT_ONLY:
2342 if (strncmp(str, regex, len) == 0)
2343 matched = 1;
2344 break;
2345 case MATCH_MIDDLE_ONLY:
2346 if (strstr(str, regex))
2347 matched = 1;
2348 break;
2349 case MATCH_END_ONLY:
2350 slen = strlen(str);
2351 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
2352 matched = 1;
2353 break;
2354 }
2355
2356 return matched;
2357}
2358
2359static int
2360enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
2361{
2362 struct ftrace_func_entry *entry;
2363 int ret = 0;
2364
2365 entry = ftrace_lookup_ip(hash, rec->ip);
2366 if (not) {
2367 /* Do nothing if it doesn't exist */
2368 if (!entry)
2369 return 0;
2370
2371 free_hash_entry(hash, entry);
2372 } else {
2373 /* Do nothing if it exists */
2374 if (entry)
2375 return 0;
2376
2377 ret = add_hash_entry(hash, rec->ip);
2378 }
2379 return ret;
2380}
2381
2382static int
2383ftrace_match_record(struct dyn_ftrace *rec, char *mod,
2384 char *regex, int len, int type)
2385{
2386 char str[KSYM_SYMBOL_LEN];
2387 char *modname;
2388
2389 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
2390
2391 if (mod) {
2392 /* module lookup requires matching the module */
2393 if (!modname || strcmp(modname, mod))
2394 return 0;
2395
2396 /* blank search means to match all funcs in the mod */
2397 if (!len)
2398 return 1;
2399 }
2400
2401 return ftrace_match(str, regex, len, type);
2402}
2403
2404static int
2405match_records(struct ftrace_hash *hash, char *buff,
2406 int len, char *mod, int not)
2407{
2408 unsigned search_len = 0;
2409 struct ftrace_page *pg;
2410 struct dyn_ftrace *rec;
2411 int type = MATCH_FULL;
2412 char *search = buff;
2413 int found = 0;
2414 int ret;
2415
2416 if (len) {
2417 type = filter_parse_regex(buff, len, &search, ¬);
2418 search_len = strlen(search);
2419 }
2420
2421 mutex_lock(&ftrace_lock);
2422
2423 if (unlikely(ftrace_disabled))
2424 goto out_unlock;
2425
2426 do_for_each_ftrace_rec(pg, rec) {
2427
2428 if (ftrace_match_record(rec, mod, search, search_len, type)) {
2429 ret = enter_record(hash, rec, not);
2430 if (ret < 0) {
2431 found = ret;
2432 goto out_unlock;
2433 }
2434 found = 1;
2435 }
2436 } while_for_each_ftrace_rec();
2437 out_unlock:
2438 mutex_unlock(&ftrace_lock);
2439
2440 return found;
2441}
2442
2443static int
2444ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
2445{
2446 return match_records(hash, buff, len, NULL, 0);
2447}
2448
2449static int
2450ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
2451{
2452 int not = 0;
2453
2454 /* blank or '*' mean the same */
2455 if (strcmp(buff, "*") == 0)
2456 buff[0] = 0;
2457
2458 /* handle the case of 'dont filter this module' */
2459 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
2460 buff[0] = 0;
2461 not = 1;
2462 }
2463
2464 return match_records(hash, buff, strlen(buff), mod, not);
2465}
2466
2467/*
2468 * We register the module command as a template to show others how
2469 * to register the a command as well.
2470 */
2471
2472static int
2473ftrace_mod_callback(struct ftrace_hash *hash,
2474 char *func, char *cmd, char *param, int enable)
2475{
2476 char *mod;
2477 int ret = -EINVAL;
2478
2479 /*
2480 * cmd == 'mod' because we only registered this func
2481 * for the 'mod' ftrace_func_command.
2482 * But if you register one func with multiple commands,
2483 * you can tell which command was used by the cmd
2484 * parameter.
2485 */
2486
2487 /* we must have a module name */
2488 if (!param)
2489 return ret;
2490
2491 mod = strsep(¶m, ":");
2492 if (!strlen(mod))
2493 return ret;
2494
2495 ret = ftrace_match_module_records(hash, func, mod);
2496 if (!ret)
2497 ret = -EINVAL;
2498 if (ret < 0)
2499 return ret;
2500
2501 return 0;
2502}
2503
2504static struct ftrace_func_command ftrace_mod_cmd = {
2505 .name = "mod",
2506 .func = ftrace_mod_callback,
2507};
2508
2509static int __init ftrace_mod_cmd_init(void)
2510{
2511 return register_ftrace_command(&ftrace_mod_cmd);
2512}
2513device_initcall(ftrace_mod_cmd_init);
2514
2515static void
2516function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
2517{
2518 struct ftrace_func_probe *entry;
2519 struct hlist_head *hhd;
2520 struct hlist_node *n;
2521 unsigned long key;
2522
2523 key = hash_long(ip, FTRACE_HASH_BITS);
2524
2525 hhd = &ftrace_func_hash[key];
2526
2527 if (hlist_empty(hhd))
2528 return;
2529
2530 /*
2531 * Disable preemption for these calls to prevent a RCU grace
2532 * period. This syncs the hash iteration and freeing of items
2533 * on the hash. rcu_read_lock is too dangerous here.
2534 */
2535 preempt_disable_notrace();
2536 hlist_for_each_entry_rcu(entry, n, hhd, node) {
2537 if (entry->ip == ip)
2538 entry->ops->func(ip, parent_ip, &entry->data);
2539 }
2540 preempt_enable_notrace();
2541}
2542
2543static struct ftrace_ops trace_probe_ops __read_mostly =
2544{
2545 .func = function_trace_probe_call,
2546};
2547
2548static int ftrace_probe_registered;
2549
2550static void __enable_ftrace_function_probe(void)
2551{
2552 int ret;
2553 int i;
2554
2555 if (ftrace_probe_registered)
2556 return;
2557
2558 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2559 struct hlist_head *hhd = &ftrace_func_hash[i];
2560 if (hhd->first)
2561 break;
2562 }
2563 /* Nothing registered? */
2564 if (i == FTRACE_FUNC_HASHSIZE)
2565 return;
2566
2567 ret = __register_ftrace_function(&trace_probe_ops);
2568 if (!ret)
2569 ret = ftrace_startup(&trace_probe_ops, 0);
2570
2571 ftrace_probe_registered = 1;
2572}
2573
2574static void __disable_ftrace_function_probe(void)
2575{
2576 int ret;
2577 int i;
2578
2579 if (!ftrace_probe_registered)
2580 return;
2581
2582 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2583 struct hlist_head *hhd = &ftrace_func_hash[i];
2584 if (hhd->first)
2585 return;
2586 }
2587
2588 /* no more funcs left */
2589 ret = __unregister_ftrace_function(&trace_probe_ops);
2590 if (!ret)
2591 ftrace_shutdown(&trace_probe_ops, 0);
2592
2593 ftrace_probe_registered = 0;
2594}
2595
2596
2597static void ftrace_free_entry_rcu(struct rcu_head *rhp)
2598{
2599 struct ftrace_func_probe *entry =
2600 container_of(rhp, struct ftrace_func_probe, rcu);
2601
2602 if (entry->ops->free)
2603 entry->ops->free(&entry->data);
2604 kfree(entry);
2605}
2606
2607
2608int
2609register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2610 void *data)
2611{
2612 struct ftrace_func_probe *entry;
2613 struct ftrace_page *pg;
2614 struct dyn_ftrace *rec;
2615 int type, len, not;
2616 unsigned long key;
2617 int count = 0;
2618 char *search;
2619
2620 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
2621 len = strlen(search);
2622
2623 /* we do not support '!' for function probes */
2624 if (WARN_ON(not))
2625 return -EINVAL;
2626
2627 mutex_lock(&ftrace_lock);
2628
2629 if (unlikely(ftrace_disabled))
2630 goto out_unlock;
2631
2632 do_for_each_ftrace_rec(pg, rec) {
2633
2634 if (!ftrace_match_record(rec, NULL, search, len, type))
2635 continue;
2636
2637 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2638 if (!entry) {
2639 /* If we did not process any, then return error */
2640 if (!count)
2641 count = -ENOMEM;
2642 goto out_unlock;
2643 }
2644
2645 count++;
2646
2647 entry->data = data;
2648
2649 /*
2650 * The caller might want to do something special
2651 * for each function we find. We call the callback
2652 * to give the caller an opportunity to do so.
2653 */
2654 if (ops->callback) {
2655 if (ops->callback(rec->ip, &entry->data) < 0) {
2656 /* caller does not like this func */
2657 kfree(entry);
2658 continue;
2659 }
2660 }
2661
2662 entry->ops = ops;
2663 entry->ip = rec->ip;
2664
2665 key = hash_long(entry->ip, FTRACE_HASH_BITS);
2666 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
2667
2668 } while_for_each_ftrace_rec();
2669 __enable_ftrace_function_probe();
2670
2671 out_unlock:
2672 mutex_unlock(&ftrace_lock);
2673
2674 return count;
2675}
2676
2677enum {
2678 PROBE_TEST_FUNC = 1,
2679 PROBE_TEST_DATA = 2
2680};
2681
2682static void
2683__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2684 void *data, int flags)
2685{
2686 struct ftrace_func_probe *entry;
2687 struct hlist_node *n, *tmp;
2688 char str[KSYM_SYMBOL_LEN];
2689 int type = MATCH_FULL;
2690 int i, len = 0;
2691 char *search;
2692
2693 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
2694 glob = NULL;
2695 else if (glob) {
2696 int not;
2697
2698 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
2699 len = strlen(search);
2700
2701 /* we do not support '!' for function probes */
2702 if (WARN_ON(not))
2703 return;
2704 }
2705
2706 mutex_lock(&ftrace_lock);
2707 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2708 struct hlist_head *hhd = &ftrace_func_hash[i];
2709
2710 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
2711
2712 /* break up if statements for readability */
2713 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
2714 continue;
2715
2716 if ((flags & PROBE_TEST_DATA) && entry->data != data)
2717 continue;
2718
2719 /* do this last, since it is the most expensive */
2720 if (glob) {
2721 kallsyms_lookup(entry->ip, NULL, NULL,
2722 NULL, str);
2723 if (!ftrace_match(str, glob, len, type))
2724 continue;
2725 }
2726
2727 hlist_del(&entry->node);
2728 call_rcu(&entry->rcu, ftrace_free_entry_rcu);
2729 }
2730 }
2731 __disable_ftrace_function_probe();
2732 mutex_unlock(&ftrace_lock);
2733}
2734
2735void
2736unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
2737 void *data)
2738{
2739 __unregister_ftrace_function_probe(glob, ops, data,
2740 PROBE_TEST_FUNC | PROBE_TEST_DATA);
2741}
2742
2743void
2744unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
2745{
2746 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
2747}
2748
2749void unregister_ftrace_function_probe_all(char *glob)
2750{
2751 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
2752}
2753
2754static LIST_HEAD(ftrace_commands);
2755static DEFINE_MUTEX(ftrace_cmd_mutex);
2756
2757int register_ftrace_command(struct ftrace_func_command *cmd)
2758{
2759 struct ftrace_func_command *p;
2760 int ret = 0;
2761
2762 mutex_lock(&ftrace_cmd_mutex);
2763 list_for_each_entry(p, &ftrace_commands, list) {
2764 if (strcmp(cmd->name, p->name) == 0) {
2765 ret = -EBUSY;
2766 goto out_unlock;
2767 }
2768 }
2769 list_add(&cmd->list, &ftrace_commands);
2770 out_unlock:
2771 mutex_unlock(&ftrace_cmd_mutex);
2772
2773 return ret;
2774}
2775
2776int unregister_ftrace_command(struct ftrace_func_command *cmd)
2777{
2778 struct ftrace_func_command *p, *n;
2779 int ret = -ENODEV;
2780
2781 mutex_lock(&ftrace_cmd_mutex);
2782 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
2783 if (strcmp(cmd->name, p->name) == 0) {
2784 ret = 0;
2785 list_del_init(&p->list);
2786 goto out_unlock;
2787 }
2788 }
2789 out_unlock:
2790 mutex_unlock(&ftrace_cmd_mutex);
2791
2792 return ret;
2793}
2794
2795static int ftrace_process_regex(struct ftrace_hash *hash,
2796 char *buff, int len, int enable)
2797{
2798 char *func, *command, *next = buff;
2799 struct ftrace_func_command *p;
2800 int ret = -EINVAL;
2801
2802 func = strsep(&next, ":");
2803
2804 if (!next) {
2805 ret = ftrace_match_records(hash, func, len);
2806 if (!ret)
2807 ret = -EINVAL;
2808 if (ret < 0)
2809 return ret;
2810 return 0;
2811 }
2812
2813 /* command found */
2814
2815 command = strsep(&next, ":");
2816
2817 mutex_lock(&ftrace_cmd_mutex);
2818 list_for_each_entry(p, &ftrace_commands, list) {
2819 if (strcmp(p->name, command) == 0) {
2820 ret = p->func(hash, func, command, next, enable);
2821 goto out_unlock;
2822 }
2823 }
2824 out_unlock:
2825 mutex_unlock(&ftrace_cmd_mutex);
2826
2827 return ret;
2828}
2829
2830static ssize_t
2831ftrace_regex_write(struct file *file, const char __user *ubuf,
2832 size_t cnt, loff_t *ppos, int enable)
2833{
2834 struct ftrace_iterator *iter;
2835 struct trace_parser *parser;
2836 ssize_t ret, read;
2837
2838 if (!cnt)
2839 return 0;
2840
2841 mutex_lock(&ftrace_regex_lock);
2842
2843 ret = -ENODEV;
2844 if (unlikely(ftrace_disabled))
2845 goto out_unlock;
2846
2847 if (file->f_mode & FMODE_READ) {
2848 struct seq_file *m = file->private_data;
2849 iter = m->private;
2850 } else
2851 iter = file->private_data;
2852
2853 parser = &iter->parser;
2854 read = trace_get_user(parser, ubuf, cnt, ppos);
2855
2856 if (read >= 0 && trace_parser_loaded(parser) &&
2857 !trace_parser_cont(parser)) {
2858 ret = ftrace_process_regex(iter->hash, parser->buffer,
2859 parser->idx, enable);
2860 trace_parser_clear(parser);
2861 if (ret)
2862 goto out_unlock;
2863 }
2864
2865 ret = read;
2866out_unlock:
2867 mutex_unlock(&ftrace_regex_lock);
2868
2869 return ret;
2870}
2871
2872static ssize_t
2873ftrace_filter_write(struct file *file, const char __user *ubuf,
2874 size_t cnt, loff_t *ppos)
2875{
2876 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
2877}
2878
2879static ssize_t
2880ftrace_notrace_write(struct file *file, const char __user *ubuf,
2881 size_t cnt, loff_t *ppos)
2882{
2883 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
2884}
2885
2886static int
2887ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
2888 int reset, int enable)
2889{
2890 struct ftrace_hash **orig_hash;
2891 struct ftrace_hash *hash;
2892 int ret;
2893
2894 /* All global ops uses the global ops filters */
2895 if (ops->flags & FTRACE_OPS_FL_GLOBAL)
2896 ops = &global_ops;
2897
2898 if (unlikely(ftrace_disabled))
2899 return -ENODEV;
2900
2901 if (enable)
2902 orig_hash = &ops->filter_hash;
2903 else
2904 orig_hash = &ops->notrace_hash;
2905
2906 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
2907 if (!hash)
2908 return -ENOMEM;
2909
2910 mutex_lock(&ftrace_regex_lock);
2911 if (reset)
2912 ftrace_filter_reset(hash);
2913 if (buf)
2914 ftrace_match_records(hash, buf, len);
2915
2916 mutex_lock(&ftrace_lock);
2917 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
2918 if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
2919 && ftrace_enabled)
2920 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
2921
2922 mutex_unlock(&ftrace_lock);
2923
2924 mutex_unlock(&ftrace_regex_lock);
2925
2926 free_ftrace_hash(hash);
2927 return ret;
2928}
2929
2930/**
2931 * ftrace_set_filter - set a function to filter on in ftrace
2932 * @ops - the ops to set the filter with
2933 * @buf - the string that holds the function filter text.
2934 * @len - the length of the string.
2935 * @reset - non zero to reset all filters before applying this filter.
2936 *
2937 * Filters denote which functions should be enabled when tracing is enabled.
2938 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2939 */
2940void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
2941 int len, int reset)
2942{
2943 ftrace_set_regex(ops, buf, len, reset, 1);
2944}
2945EXPORT_SYMBOL_GPL(ftrace_set_filter);
2946
2947/**
2948 * ftrace_set_notrace - set a function to not trace in ftrace
2949 * @ops - the ops to set the notrace filter with
2950 * @buf - the string that holds the function notrace text.
2951 * @len - the length of the string.
2952 * @reset - non zero to reset all filters before applying this filter.
2953 *
2954 * Notrace Filters denote which functions should not be enabled when tracing
2955 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2956 * for tracing.
2957 */
2958void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
2959 int len, int reset)
2960{
2961 ftrace_set_regex(ops, buf, len, reset, 0);
2962}
2963EXPORT_SYMBOL_GPL(ftrace_set_notrace);
2964/**
2965 * ftrace_set_filter - set a function to filter on in ftrace
2966 * @ops - the ops to set the filter with
2967 * @buf - the string that holds the function filter text.
2968 * @len - the length of the string.
2969 * @reset - non zero to reset all filters before applying this filter.
2970 *
2971 * Filters denote which functions should be enabled when tracing is enabled.
2972 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2973 */
2974void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
2975{
2976 ftrace_set_regex(&global_ops, buf, len, reset, 1);
2977}
2978EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
2979
2980/**
2981 * ftrace_set_notrace - set a function to not trace in ftrace
2982 * @ops - the ops to set the notrace filter with
2983 * @buf - the string that holds the function notrace text.
2984 * @len - the length of the string.
2985 * @reset - non zero to reset all filters before applying this filter.
2986 *
2987 * Notrace Filters denote which functions should not be enabled when tracing
2988 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2989 * for tracing.
2990 */
2991void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
2992{
2993 ftrace_set_regex(&global_ops, buf, len, reset, 0);
2994}
2995EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
2996
2997/*
2998 * command line interface to allow users to set filters on boot up.
2999 */
3000#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3001static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3002static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
3003
3004static int __init set_ftrace_notrace(char *str)
3005{
3006 strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
3007 return 1;
3008}
3009__setup("ftrace_notrace=", set_ftrace_notrace);
3010
3011static int __init set_ftrace_filter(char *str)
3012{
3013 strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
3014 return 1;
3015}
3016__setup("ftrace_filter=", set_ftrace_filter);
3017
3018#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3019static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
3020static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
3021
3022static int __init set_graph_function(char *str)
3023{
3024 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
3025 return 1;
3026}
3027__setup("ftrace_graph_filter=", set_graph_function);
3028
3029static void __init set_ftrace_early_graph(char *buf)
3030{
3031 int ret;
3032 char *func;
3033
3034 while (buf) {
3035 func = strsep(&buf, ",");
3036 /* we allow only one expression at a time */
3037 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3038 func);
3039 if (ret)
3040 printk(KERN_DEBUG "ftrace: function %s not "
3041 "traceable\n", func);
3042 }
3043}
3044#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3045
3046static void __init
3047set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable)
3048{
3049 char *func;
3050
3051 while (buf) {
3052 func = strsep(&buf, ",");
3053 ftrace_set_regex(ops, func, strlen(func), 0, enable);
3054 }
3055}
3056
3057static void __init set_ftrace_early_filters(void)
3058{
3059 if (ftrace_filter_buf[0])
3060 set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1);
3061 if (ftrace_notrace_buf[0])
3062 set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0);
3063#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3064 if (ftrace_graph_buf[0])
3065 set_ftrace_early_graph(ftrace_graph_buf);
3066#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3067}
3068
3069static int
3070ftrace_regex_release(struct inode *inode, struct file *file)
3071{
3072 struct seq_file *m = (struct seq_file *)file->private_data;
3073 struct ftrace_iterator *iter;
3074 struct ftrace_hash **orig_hash;
3075 struct trace_parser *parser;
3076 int filter_hash;
3077 int ret;
3078
3079 mutex_lock(&ftrace_regex_lock);
3080 if (file->f_mode & FMODE_READ) {
3081 iter = m->private;
3082
3083 seq_release(inode, file);
3084 } else
3085 iter = file->private_data;
3086
3087 parser = &iter->parser;
3088 if (trace_parser_loaded(parser)) {
3089 parser->buffer[parser->idx] = 0;
3090 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
3091 }
3092
3093 trace_parser_put(parser);
3094
3095 if (file->f_mode & FMODE_WRITE) {
3096 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
3097
3098 if (filter_hash)
3099 orig_hash = &iter->ops->filter_hash;
3100 else
3101 orig_hash = &iter->ops->notrace_hash;
3102
3103 mutex_lock(&ftrace_lock);
3104 ret = ftrace_hash_move(iter->ops, filter_hash,
3105 orig_hash, iter->hash);
3106 if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
3107 && ftrace_enabled)
3108 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
3109
3110 mutex_unlock(&ftrace_lock);
3111 }
3112 free_ftrace_hash(iter->hash);
3113 kfree(iter);
3114
3115 mutex_unlock(&ftrace_regex_lock);
3116 return 0;
3117}
3118
3119static const struct file_operations ftrace_avail_fops = {
3120 .open = ftrace_avail_open,
3121 .read = seq_read,
3122 .llseek = seq_lseek,
3123 .release = seq_release_private,
3124};
3125
3126static const struct file_operations ftrace_enabled_fops = {
3127 .open = ftrace_enabled_open,
3128 .read = seq_read,
3129 .llseek = seq_lseek,
3130 .release = seq_release_private,
3131};
3132
3133static const struct file_operations ftrace_filter_fops = {
3134 .open = ftrace_filter_open,
3135 .read = seq_read,
3136 .write = ftrace_filter_write,
3137 .llseek = ftrace_regex_lseek,
3138 .release = ftrace_regex_release,
3139};
3140
3141static const struct file_operations ftrace_notrace_fops = {
3142 .open = ftrace_notrace_open,
3143 .read = seq_read,
3144 .write = ftrace_notrace_write,
3145 .llseek = ftrace_regex_lseek,
3146 .release = ftrace_regex_release,
3147};
3148
3149#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3150
3151static DEFINE_MUTEX(graph_lock);
3152
3153int ftrace_graph_count;
3154int ftrace_graph_filter_enabled;
3155unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
3156
3157static void *
3158__g_next(struct seq_file *m, loff_t *pos)
3159{
3160 if (*pos >= ftrace_graph_count)
3161 return NULL;
3162 return &ftrace_graph_funcs[*pos];
3163}
3164
3165static void *
3166g_next(struct seq_file *m, void *v, loff_t *pos)
3167{
3168 (*pos)++;
3169 return __g_next(m, pos);
3170}
3171
3172static void *g_start(struct seq_file *m, loff_t *pos)
3173{
3174 mutex_lock(&graph_lock);
3175
3176 /* Nothing, tell g_show to print all functions are enabled */
3177 if (!ftrace_graph_filter_enabled && !*pos)
3178 return (void *)1;
3179
3180 return __g_next(m, pos);
3181}
3182
3183static void g_stop(struct seq_file *m, void *p)
3184{
3185 mutex_unlock(&graph_lock);
3186}
3187
3188static int g_show(struct seq_file *m, void *v)
3189{
3190 unsigned long *ptr = v;
3191
3192 if (!ptr)
3193 return 0;
3194
3195 if (ptr == (unsigned long *)1) {
3196 seq_printf(m, "#### all functions enabled ####\n");
3197 return 0;
3198 }
3199
3200 seq_printf(m, "%ps\n", (void *)*ptr);
3201
3202 return 0;
3203}
3204
3205static const struct seq_operations ftrace_graph_seq_ops = {
3206 .start = g_start,
3207 .next = g_next,
3208 .stop = g_stop,
3209 .show = g_show,
3210};
3211
3212static int
3213ftrace_graph_open(struct inode *inode, struct file *file)
3214{
3215 int ret = 0;
3216
3217 if (unlikely(ftrace_disabled))
3218 return -ENODEV;
3219
3220 mutex_lock(&graph_lock);
3221 if ((file->f_mode & FMODE_WRITE) &&
3222 (file->f_flags & O_TRUNC)) {
3223 ftrace_graph_filter_enabled = 0;
3224 ftrace_graph_count = 0;
3225 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
3226 }
3227 mutex_unlock(&graph_lock);
3228
3229 if (file->f_mode & FMODE_READ)
3230 ret = seq_open(file, &ftrace_graph_seq_ops);
3231
3232 return ret;
3233}
3234
3235static int
3236ftrace_graph_release(struct inode *inode, struct file *file)
3237{
3238 if (file->f_mode & FMODE_READ)
3239 seq_release(inode, file);
3240 return 0;
3241}
3242
3243static int
3244ftrace_set_func(unsigned long *array, int *idx, char *buffer)
3245{
3246 struct dyn_ftrace *rec;
3247 struct ftrace_page *pg;
3248 int search_len;
3249 int fail = 1;
3250 int type, not;
3251 char *search;
3252 bool exists;
3253 int i;
3254
3255 /* decode regex */
3256 type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
3257 if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
3258 return -EBUSY;
3259
3260 search_len = strlen(search);
3261
3262 mutex_lock(&ftrace_lock);
3263
3264 if (unlikely(ftrace_disabled)) {
3265 mutex_unlock(&ftrace_lock);
3266 return -ENODEV;
3267 }
3268
3269 do_for_each_ftrace_rec(pg, rec) {
3270
3271 if (rec->flags & FTRACE_FL_FREE)
3272 continue;
3273
3274 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
3275 /* if it is in the array */
3276 exists = false;
3277 for (i = 0; i < *idx; i++) {
3278 if (array[i] == rec->ip) {
3279 exists = true;
3280 break;
3281 }
3282 }
3283
3284 if (!not) {
3285 fail = 0;
3286 if (!exists) {
3287 array[(*idx)++] = rec->ip;
3288 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
3289 goto out;
3290 }
3291 } else {
3292 if (exists) {
3293 array[i] = array[--(*idx)];
3294 array[*idx] = 0;
3295 fail = 0;
3296 }
3297 }
3298 }
3299 } while_for_each_ftrace_rec();
3300out:
3301 mutex_unlock(&ftrace_lock);
3302
3303 if (fail)
3304 return -EINVAL;
3305
3306 ftrace_graph_filter_enabled = 1;
3307 return 0;
3308}
3309
3310static ssize_t
3311ftrace_graph_write(struct file *file, const char __user *ubuf,
3312 size_t cnt, loff_t *ppos)
3313{
3314 struct trace_parser parser;
3315 ssize_t read, ret;
3316
3317 if (!cnt)
3318 return 0;
3319
3320 mutex_lock(&graph_lock);
3321
3322 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
3323 ret = -ENOMEM;
3324 goto out_unlock;
3325 }
3326
3327 read = trace_get_user(&parser, ubuf, cnt, ppos);
3328
3329 if (read >= 0 && trace_parser_loaded((&parser))) {
3330 parser.buffer[parser.idx] = 0;
3331
3332 /* we allow only one expression at a time */
3333 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3334 parser.buffer);
3335 if (ret)
3336 goto out_free;
3337 }
3338
3339 ret = read;
3340
3341out_free:
3342 trace_parser_put(&parser);
3343out_unlock:
3344 mutex_unlock(&graph_lock);
3345
3346 return ret;
3347}
3348
3349static const struct file_operations ftrace_graph_fops = {
3350 .open = ftrace_graph_open,
3351 .read = seq_read,
3352 .write = ftrace_graph_write,
3353 .release = ftrace_graph_release,
3354 .llseek = seq_lseek,
3355};
3356#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3357
3358static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
3359{
3360
3361 trace_create_file("available_filter_functions", 0444,
3362 d_tracer, NULL, &ftrace_avail_fops);
3363
3364 trace_create_file("enabled_functions", 0444,
3365 d_tracer, NULL, &ftrace_enabled_fops);
3366
3367 trace_create_file("set_ftrace_filter", 0644, d_tracer,
3368 NULL, &ftrace_filter_fops);
3369
3370 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
3371 NULL, &ftrace_notrace_fops);
3372
3373#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3374 trace_create_file("set_graph_function", 0444, d_tracer,
3375 NULL,
3376 &ftrace_graph_fops);
3377#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3378
3379 return 0;
3380}
3381
3382static int ftrace_process_locs(struct module *mod,
3383 unsigned long *start,
3384 unsigned long *end)
3385{
3386 unsigned long *p;
3387 unsigned long addr;
3388 unsigned long flags = 0; /* Shut up gcc */
3389
3390 mutex_lock(&ftrace_lock);
3391 p = start;
3392 while (p < end) {
3393 addr = ftrace_call_adjust(*p++);
3394 /*
3395 * Some architecture linkers will pad between
3396 * the different mcount_loc sections of different
3397 * object files to satisfy alignments.
3398 * Skip any NULL pointers.
3399 */
3400 if (!addr)
3401 continue;
3402 ftrace_record_ip(addr);
3403 }
3404
3405 /*
3406 * We only need to disable interrupts on start up
3407 * because we are modifying code that an interrupt
3408 * may execute, and the modification is not atomic.
3409 * But for modules, nothing runs the code we modify
3410 * until we are finished with it, and there's no
3411 * reason to cause large interrupt latencies while we do it.
3412 */
3413 if (!mod)
3414 local_irq_save(flags);
3415 ftrace_update_code(mod);
3416 if (!mod)
3417 local_irq_restore(flags);
3418 mutex_unlock(&ftrace_lock);
3419
3420 return 0;
3421}
3422
3423#ifdef CONFIG_MODULES
3424void ftrace_release_mod(struct module *mod)
3425{
3426 struct dyn_ftrace *rec;
3427 struct ftrace_page *pg;
3428
3429 mutex_lock(&ftrace_lock);
3430
3431 if (ftrace_disabled)
3432 goto out_unlock;
3433
3434 do_for_each_ftrace_rec(pg, rec) {
3435 if (within_module_core(rec->ip, mod)) {
3436 /*
3437 * rec->ip is changed in ftrace_free_rec()
3438 * It should not between s and e if record was freed.
3439 */
3440 FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE);
3441 ftrace_free_rec(rec);
3442 }
3443 } while_for_each_ftrace_rec();
3444 out_unlock:
3445 mutex_unlock(&ftrace_lock);
3446}
3447
3448static void ftrace_init_module(struct module *mod,
3449 unsigned long *start, unsigned long *end)
3450{
3451 if (ftrace_disabled || start == end)
3452 return;
3453 ftrace_process_locs(mod, start, end);
3454}
3455
3456static int ftrace_module_notify(struct notifier_block *self,
3457 unsigned long val, void *data)
3458{
3459 struct module *mod = data;
3460
3461 switch (val) {
3462 case MODULE_STATE_COMING:
3463 ftrace_init_module(mod, mod->ftrace_callsites,
3464 mod->ftrace_callsites +
3465 mod->num_ftrace_callsites);
3466 break;
3467 case MODULE_STATE_GOING:
3468 ftrace_release_mod(mod);
3469 break;
3470 }
3471
3472 return 0;
3473}
3474#else
3475static int ftrace_module_notify(struct notifier_block *self,
3476 unsigned long val, void *data)
3477{
3478 return 0;
3479}
3480#endif /* CONFIG_MODULES */
3481
3482struct notifier_block ftrace_module_nb = {
3483 .notifier_call = ftrace_module_notify,
3484 .priority = 0,
3485};
3486
3487extern unsigned long __start_mcount_loc[];
3488extern unsigned long __stop_mcount_loc[];
3489
3490void __init ftrace_init(void)
3491{
3492 unsigned long count, addr, flags;
3493 int ret;
3494
3495 /* Keep the ftrace pointer to the stub */
3496 addr = (unsigned long)ftrace_stub;
3497
3498 local_irq_save(flags);
3499 ftrace_dyn_arch_init(&addr);
3500 local_irq_restore(flags);
3501
3502 /* ftrace_dyn_arch_init places the return code in addr */
3503 if (addr)
3504 goto failed;
3505
3506 count = __stop_mcount_loc - __start_mcount_loc;
3507
3508 ret = ftrace_dyn_table_alloc(count);
3509 if (ret)
3510 goto failed;
3511
3512 last_ftrace_enabled = ftrace_enabled = 1;
3513
3514 ret = ftrace_process_locs(NULL,
3515 __start_mcount_loc,
3516 __stop_mcount_loc);
3517
3518 ret = register_module_notifier(&ftrace_module_nb);
3519 if (ret)
3520 pr_warning("Failed to register trace ftrace module notifier\n");
3521
3522 set_ftrace_early_filters();
3523
3524 return;
3525 failed:
3526 ftrace_disabled = 1;
3527}
3528
3529#else
3530
3531static struct ftrace_ops global_ops = {
3532 .func = ftrace_stub,
3533};
3534
3535static int __init ftrace_nodyn_init(void)
3536{
3537 ftrace_enabled = 1;
3538 return 0;
3539}
3540device_initcall(ftrace_nodyn_init);
3541
3542static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
3543static inline void ftrace_startup_enable(int command) { }
3544/* Keep as macros so we do not need to define the commands */
3545# define ftrace_startup(ops, command) \
3546 ({ \
3547 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
3548 0; \
3549 })
3550# define ftrace_shutdown(ops, command) do { } while (0)
3551# define ftrace_startup_sysctl() do { } while (0)
3552# define ftrace_shutdown_sysctl() do { } while (0)
3553
3554static inline int
3555ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
3556{
3557 return 1;
3558}
3559
3560#endif /* CONFIG_DYNAMIC_FTRACE */
3561
3562static void
3563ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
3564{
3565 struct ftrace_ops *op;
3566
3567 if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
3568 return;
3569
3570 trace_recursion_set(TRACE_INTERNAL_BIT);
3571 /*
3572 * Some of the ops may be dynamically allocated,
3573 * they must be freed after a synchronize_sched().
3574 */
3575 preempt_disable_notrace();
3576 op = rcu_dereference_raw(ftrace_ops_list);
3577 while (op != &ftrace_list_end) {
3578 if (ftrace_ops_test(op, ip))
3579 op->func(ip, parent_ip);
3580 op = rcu_dereference_raw(op->next);
3581 };
3582 preempt_enable_notrace();
3583 trace_recursion_clear(TRACE_INTERNAL_BIT);
3584}
3585
3586static void clear_ftrace_swapper(void)
3587{
3588 struct task_struct *p;
3589 int cpu;
3590
3591 get_online_cpus();
3592 for_each_online_cpu(cpu) {
3593 p = idle_task(cpu);
3594 clear_tsk_trace_trace(p);
3595 }
3596 put_online_cpus();
3597}
3598
3599static void set_ftrace_swapper(void)
3600{
3601 struct task_struct *p;
3602 int cpu;
3603
3604 get_online_cpus();
3605 for_each_online_cpu(cpu) {
3606 p = idle_task(cpu);
3607 set_tsk_trace_trace(p);
3608 }
3609 put_online_cpus();
3610}
3611
3612static void clear_ftrace_pid(struct pid *pid)
3613{
3614 struct task_struct *p;
3615
3616 rcu_read_lock();
3617 do_each_pid_task(pid, PIDTYPE_PID, p) {
3618 clear_tsk_trace_trace(p);
3619 } while_each_pid_task(pid, PIDTYPE_PID, p);
3620 rcu_read_unlock();
3621
3622 put_pid(pid);
3623}
3624
3625static void set_ftrace_pid(struct pid *pid)
3626{
3627 struct task_struct *p;
3628
3629 rcu_read_lock();
3630 do_each_pid_task(pid, PIDTYPE_PID, p) {
3631 set_tsk_trace_trace(p);
3632 } while_each_pid_task(pid, PIDTYPE_PID, p);
3633 rcu_read_unlock();
3634}
3635
3636static void clear_ftrace_pid_task(struct pid *pid)
3637{
3638 if (pid == ftrace_swapper_pid)
3639 clear_ftrace_swapper();
3640 else
3641 clear_ftrace_pid(pid);
3642}
3643
3644static void set_ftrace_pid_task(struct pid *pid)
3645{
3646 if (pid == ftrace_swapper_pid)
3647 set_ftrace_swapper();
3648 else
3649 set_ftrace_pid(pid);
3650}
3651
3652static int ftrace_pid_add(int p)
3653{
3654 struct pid *pid;
3655 struct ftrace_pid *fpid;
3656 int ret = -EINVAL;
3657
3658 mutex_lock(&ftrace_lock);
3659
3660 if (!p)
3661 pid = ftrace_swapper_pid;
3662 else
3663 pid = find_get_pid(p);
3664
3665 if (!pid)
3666 goto out;
3667
3668 ret = 0;
3669
3670 list_for_each_entry(fpid, &ftrace_pids, list)
3671 if (fpid->pid == pid)
3672 goto out_put;
3673
3674 ret = -ENOMEM;
3675
3676 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
3677 if (!fpid)
3678 goto out_put;
3679
3680 list_add(&fpid->list, &ftrace_pids);
3681 fpid->pid = pid;
3682
3683 set_ftrace_pid_task(pid);
3684
3685 ftrace_update_pid_func();
3686 ftrace_startup_enable(0);
3687
3688 mutex_unlock(&ftrace_lock);
3689 return 0;
3690
3691out_put:
3692 if (pid != ftrace_swapper_pid)
3693 put_pid(pid);
3694
3695out:
3696 mutex_unlock(&ftrace_lock);
3697 return ret;
3698}
3699
3700static void ftrace_pid_reset(void)
3701{
3702 struct ftrace_pid *fpid, *safe;
3703
3704 mutex_lock(&ftrace_lock);
3705 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
3706 struct pid *pid = fpid->pid;
3707
3708 clear_ftrace_pid_task(pid);
3709
3710 list_del(&fpid->list);
3711 kfree(fpid);
3712 }
3713
3714 ftrace_update_pid_func();
3715 ftrace_startup_enable(0);
3716
3717 mutex_unlock(&ftrace_lock);
3718}
3719
3720static void *fpid_start(struct seq_file *m, loff_t *pos)
3721{
3722 mutex_lock(&ftrace_lock);
3723
3724 if (list_empty(&ftrace_pids) && (!*pos))
3725 return (void *) 1;
3726
3727 return seq_list_start(&ftrace_pids, *pos);
3728}
3729
3730static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
3731{
3732 if (v == (void *)1)
3733 return NULL;
3734
3735 return seq_list_next(v, &ftrace_pids, pos);
3736}
3737
3738static void fpid_stop(struct seq_file *m, void *p)
3739{
3740 mutex_unlock(&ftrace_lock);
3741}
3742
3743static int fpid_show(struct seq_file *m, void *v)
3744{
3745 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
3746
3747 if (v == (void *)1) {
3748 seq_printf(m, "no pid\n");
3749 return 0;
3750 }
3751
3752 if (fpid->pid == ftrace_swapper_pid)
3753 seq_printf(m, "swapper tasks\n");
3754 else
3755 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
3756
3757 return 0;
3758}
3759
3760static const struct seq_operations ftrace_pid_sops = {
3761 .start = fpid_start,
3762 .next = fpid_next,
3763 .stop = fpid_stop,
3764 .show = fpid_show,
3765};
3766
3767static int
3768ftrace_pid_open(struct inode *inode, struct file *file)
3769{
3770 int ret = 0;
3771
3772 if ((file->f_mode & FMODE_WRITE) &&
3773 (file->f_flags & O_TRUNC))
3774 ftrace_pid_reset();
3775
3776 if (file->f_mode & FMODE_READ)
3777 ret = seq_open(file, &ftrace_pid_sops);
3778
3779 return ret;
3780}
3781
3782static ssize_t
3783ftrace_pid_write(struct file *filp, const char __user *ubuf,
3784 size_t cnt, loff_t *ppos)
3785{
3786 char buf[64], *tmp;
3787 long val;
3788 int ret;
3789
3790 if (cnt >= sizeof(buf))
3791 return -EINVAL;
3792
3793 if (copy_from_user(&buf, ubuf, cnt))
3794 return -EFAULT;
3795
3796 buf[cnt] = 0;
3797
3798 /*
3799 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
3800 * to clean the filter quietly.
3801 */
3802 tmp = strstrip(buf);
3803 if (strlen(tmp) == 0)
3804 return 1;
3805
3806 ret = strict_strtol(tmp, 10, &val);
3807 if (ret < 0)
3808 return ret;
3809
3810 ret = ftrace_pid_add(val);
3811
3812 return ret ? ret : cnt;
3813}
3814
3815static int
3816ftrace_pid_release(struct inode *inode, struct file *file)
3817{
3818 if (file->f_mode & FMODE_READ)
3819 seq_release(inode, file);
3820
3821 return 0;
3822}
3823
3824static const struct file_operations ftrace_pid_fops = {
3825 .open = ftrace_pid_open,
3826 .write = ftrace_pid_write,
3827 .read = seq_read,
3828 .llseek = seq_lseek,
3829 .release = ftrace_pid_release,
3830};
3831
3832static __init int ftrace_init_debugfs(void)
3833{
3834 struct dentry *d_tracer;
3835
3836 d_tracer = tracing_init_dentry();
3837 if (!d_tracer)
3838 return 0;
3839
3840 ftrace_init_dyn_debugfs(d_tracer);
3841
3842 trace_create_file("set_ftrace_pid", 0644, d_tracer,
3843 NULL, &ftrace_pid_fops);
3844
3845 ftrace_profile_debugfs(d_tracer);
3846
3847 return 0;
3848}
3849fs_initcall(ftrace_init_debugfs);
3850
3851/**
3852 * ftrace_kill - kill ftrace
3853 *
3854 * This function should be used by panic code. It stops ftrace
3855 * but in a not so nice way. If you need to simply kill ftrace
3856 * from a non-atomic section, use ftrace_kill.
3857 */
3858void ftrace_kill(void)
3859{
3860 ftrace_disabled = 1;
3861 ftrace_enabled = 0;
3862 clear_ftrace_function();
3863}
3864
3865/**
3866 * register_ftrace_function - register a function for profiling
3867 * @ops - ops structure that holds the function for profiling.
3868 *
3869 * Register a function to be called by all functions in the
3870 * kernel.
3871 *
3872 * Note: @ops->func and all the functions it calls must be labeled
3873 * with "notrace", otherwise it will go into a
3874 * recursive loop.
3875 */
3876int register_ftrace_function(struct ftrace_ops *ops)
3877{
3878 int ret = -1;
3879
3880 mutex_lock(&ftrace_lock);
3881
3882 if (unlikely(ftrace_disabled))
3883 goto out_unlock;
3884
3885 ret = __register_ftrace_function(ops);
3886 if (!ret)
3887 ret = ftrace_startup(ops, 0);
3888
3889
3890 out_unlock:
3891 mutex_unlock(&ftrace_lock);
3892 return ret;
3893}
3894EXPORT_SYMBOL_GPL(register_ftrace_function);
3895
3896/**
3897 * unregister_ftrace_function - unregister a function for profiling.
3898 * @ops - ops structure that holds the function to unregister
3899 *
3900 * Unregister a function that was added to be called by ftrace profiling.
3901 */
3902int unregister_ftrace_function(struct ftrace_ops *ops)
3903{
3904 int ret;
3905
3906 mutex_lock(&ftrace_lock);
3907 ret = __unregister_ftrace_function(ops);
3908 if (!ret)
3909 ftrace_shutdown(ops, 0);
3910 mutex_unlock(&ftrace_lock);
3911
3912 return ret;
3913}
3914EXPORT_SYMBOL_GPL(unregister_ftrace_function);
3915
3916int
3917ftrace_enable_sysctl(struct ctl_table *table, int write,
3918 void __user *buffer, size_t *lenp,
3919 loff_t *ppos)
3920{
3921 int ret = -ENODEV;
3922
3923 mutex_lock(&ftrace_lock);
3924
3925 if (unlikely(ftrace_disabled))
3926 goto out;
3927
3928 ret = proc_dointvec(table, write, buffer, lenp, ppos);
3929
3930 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
3931 goto out;
3932
3933 last_ftrace_enabled = !!ftrace_enabled;
3934
3935 if (ftrace_enabled) {
3936
3937 ftrace_startup_sysctl();
3938
3939 /* we are starting ftrace again */
3940 if (ftrace_ops_list != &ftrace_list_end) {
3941 if (ftrace_ops_list->next == &ftrace_list_end)
3942 ftrace_trace_function = ftrace_ops_list->func;
3943 else
3944 ftrace_trace_function = ftrace_ops_list_func;
3945 }
3946
3947 } else {
3948 /* stopping ftrace calls (just send to ftrace_stub) */
3949 ftrace_trace_function = ftrace_stub;
3950
3951 ftrace_shutdown_sysctl();
3952 }
3953
3954 out:
3955 mutex_unlock(&ftrace_lock);
3956 return ret;
3957}
3958
3959#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3960
3961static int ftrace_graph_active;
3962static struct notifier_block ftrace_suspend_notifier;
3963
3964int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
3965{
3966 return 0;
3967}
3968
3969/* The callbacks that hook a function */
3970trace_func_graph_ret_t ftrace_graph_return =
3971 (trace_func_graph_ret_t)ftrace_stub;
3972trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
3973
3974/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
3975static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
3976{
3977 int i;
3978 int ret = 0;
3979 unsigned long flags;
3980 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
3981 struct task_struct *g, *t;
3982
3983 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
3984 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
3985 * sizeof(struct ftrace_ret_stack),
3986 GFP_KERNEL);
3987 if (!ret_stack_list[i]) {
3988 start = 0;
3989 end = i;
3990 ret = -ENOMEM;
3991 goto free;
3992 }
3993 }
3994
3995 read_lock_irqsave(&tasklist_lock, flags);
3996 do_each_thread(g, t) {
3997 if (start == end) {
3998 ret = -EAGAIN;
3999 goto unlock;
4000 }
4001
4002 if (t->ret_stack == NULL) {
4003 atomic_set(&t->tracing_graph_pause, 0);
4004 atomic_set(&t->trace_overrun, 0);
4005 t->curr_ret_stack = -1;
4006 /* Make sure the tasks see the -1 first: */
4007 smp_wmb();
4008 t->ret_stack = ret_stack_list[start++];
4009 }
4010 } while_each_thread(g, t);
4011
4012unlock:
4013 read_unlock_irqrestore(&tasklist_lock, flags);
4014free:
4015 for (i = start; i < end; i++)
4016 kfree(ret_stack_list[i]);
4017 return ret;
4018}
4019
4020static void
4021ftrace_graph_probe_sched_switch(void *ignore,
4022 struct task_struct *prev, struct task_struct *next)
4023{
4024 unsigned long long timestamp;
4025 int index;
4026
4027 /*
4028 * Does the user want to count the time a function was asleep.
4029 * If so, do not update the time stamps.
4030 */
4031 if (trace_flags & TRACE_ITER_SLEEP_TIME)
4032 return;
4033
4034 timestamp = trace_clock_local();
4035
4036 prev->ftrace_timestamp = timestamp;
4037
4038 /* only process tasks that we timestamped */
4039 if (!next->ftrace_timestamp)
4040 return;
4041
4042 /*
4043 * Update all the counters in next to make up for the
4044 * time next was sleeping.
4045 */
4046 timestamp -= next->ftrace_timestamp;
4047
4048 for (index = next->curr_ret_stack; index >= 0; index--)
4049 next->ret_stack[index].calltime += timestamp;
4050}
4051
4052/* Allocate a return stack for each task */
4053static int start_graph_tracing(void)
4054{
4055 struct ftrace_ret_stack **ret_stack_list;
4056 int ret, cpu;
4057
4058 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
4059 sizeof(struct ftrace_ret_stack *),
4060 GFP_KERNEL);
4061
4062 if (!ret_stack_list)
4063 return -ENOMEM;
4064
4065 /* The cpu_boot init_task->ret_stack will never be freed */
4066 for_each_online_cpu(cpu) {
4067 if (!idle_task(cpu)->ret_stack)
4068 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
4069 }
4070
4071 do {
4072 ret = alloc_retstack_tasklist(ret_stack_list);
4073 } while (ret == -EAGAIN);
4074
4075 if (!ret) {
4076 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4077 if (ret)
4078 pr_info("ftrace_graph: Couldn't activate tracepoint"
4079 " probe to kernel_sched_switch\n");
4080 }
4081
4082 kfree(ret_stack_list);
4083 return ret;
4084}
4085
4086/*
4087 * Hibernation protection.
4088 * The state of the current task is too much unstable during
4089 * suspend/restore to disk. We want to protect against that.
4090 */
4091static int
4092ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
4093 void *unused)
4094{
4095 switch (state) {
4096 case PM_HIBERNATION_PREPARE:
4097 pause_graph_tracing();
4098 break;
4099
4100 case PM_POST_HIBERNATION:
4101 unpause_graph_tracing();
4102 break;
4103 }
4104 return NOTIFY_DONE;
4105}
4106
4107int register_ftrace_graph(trace_func_graph_ret_t retfunc,
4108 trace_func_graph_ent_t entryfunc)
4109{
4110 int ret = 0;
4111
4112 mutex_lock(&ftrace_lock);
4113
4114 /* we currently allow only one tracer registered at a time */
4115 if (ftrace_graph_active) {
4116 ret = -EBUSY;
4117 goto out;
4118 }
4119
4120 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
4121 register_pm_notifier(&ftrace_suspend_notifier);
4122
4123 ftrace_graph_active++;
4124 ret = start_graph_tracing();
4125 if (ret) {
4126 ftrace_graph_active--;
4127 goto out;
4128 }
4129
4130 ftrace_graph_return = retfunc;
4131 ftrace_graph_entry = entryfunc;
4132
4133 ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
4134
4135out:
4136 mutex_unlock(&ftrace_lock);
4137 return ret;
4138}
4139
4140void unregister_ftrace_graph(void)
4141{
4142 mutex_lock(&ftrace_lock);
4143
4144 if (unlikely(!ftrace_graph_active))
4145 goto out;
4146
4147 ftrace_graph_active--;
4148 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
4149 ftrace_graph_entry = ftrace_graph_entry_stub;
4150 ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
4151 unregister_pm_notifier(&ftrace_suspend_notifier);
4152 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4153
4154 out:
4155 mutex_unlock(&ftrace_lock);
4156}
4157
4158static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
4159
4160static void
4161graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
4162{
4163 atomic_set(&t->tracing_graph_pause, 0);
4164 atomic_set(&t->trace_overrun, 0);
4165 t->ftrace_timestamp = 0;
4166 /* make curr_ret_stack visible before we add the ret_stack */
4167 smp_wmb();
4168 t->ret_stack = ret_stack;
4169}
4170
4171/*
4172 * Allocate a return stack for the idle task. May be the first
4173 * time through, or it may be done by CPU hotplug online.
4174 */
4175void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
4176{
4177 t->curr_ret_stack = -1;
4178 /*
4179 * The idle task has no parent, it either has its own
4180 * stack or no stack at all.
4181 */
4182 if (t->ret_stack)
4183 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
4184
4185 if (ftrace_graph_active) {
4186 struct ftrace_ret_stack *ret_stack;
4187
4188 ret_stack = per_cpu(idle_ret_stack, cpu);
4189 if (!ret_stack) {
4190 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4191 * sizeof(struct ftrace_ret_stack),
4192 GFP_KERNEL);
4193 if (!ret_stack)
4194 return;
4195 per_cpu(idle_ret_stack, cpu) = ret_stack;
4196 }
4197 graph_init_task(t, ret_stack);
4198 }
4199}
4200
4201/* Allocate a return stack for newly created task */
4202void ftrace_graph_init_task(struct task_struct *t)
4203{
4204 /* Make sure we do not use the parent ret_stack */
4205 t->ret_stack = NULL;
4206 t->curr_ret_stack = -1;
4207
4208 if (ftrace_graph_active) {
4209 struct ftrace_ret_stack *ret_stack;
4210
4211 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4212 * sizeof(struct ftrace_ret_stack),
4213 GFP_KERNEL);
4214 if (!ret_stack)
4215 return;
4216 graph_init_task(t, ret_stack);
4217 }
4218}
4219
4220void ftrace_graph_exit_task(struct task_struct *t)
4221{
4222 struct ftrace_ret_stack *ret_stack = t->ret_stack;
4223
4224 t->ret_stack = NULL;
4225 /* NULL must become visible to IRQs before we free it: */
4226 barrier();
4227
4228 kfree(ret_stack);
4229}
4230
4231void ftrace_graph_stop(void)
4232{
4233 ftrace_stop();
4234}
4235#endif