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