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1// SPDX-License-Identifier: GPL-2.0
2/*
3 *
4 * Function graph tracer.
5 * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
6 * Mostly borrowed from function tracer which
7 * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
8 *
9 */
10#include <linux/uaccess.h>
11#include <linux/ftrace.h>
12#include <linux/interrupt.h>
13#include <linux/slab.h>
14#include <linux/fs.h>
15
16#include "trace.h"
17#include "trace_output.h"
18
19/* When set, irq functions will be ignored */
20static int ftrace_graph_skip_irqs;
21
22struct fgraph_cpu_data {
23 pid_t last_pid;
24 int depth;
25 int depth_irq;
26 int ignore;
27 unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH];
28};
29
30struct fgraph_data {
31 struct fgraph_cpu_data __percpu *cpu_data;
32
33 /* Place to preserve last processed entry. */
34 struct ftrace_graph_ent_entry ent;
35 struct ftrace_graph_ret_entry ret;
36 int failed;
37 int cpu;
38};
39
40#define TRACE_GRAPH_INDENT 2
41
42unsigned int fgraph_max_depth;
43
44static struct tracer_opt trace_opts[] = {
45 /* Display overruns? (for self-debug purpose) */
46 { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
47 /* Display CPU ? */
48 { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
49 /* Display Overhead ? */
50 { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
51 /* Display proc name/pid */
52 { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
53 /* Display duration of execution */
54 { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
55 /* Display absolute time of an entry */
56 { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
57 /* Display interrupts */
58 { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
59 /* Display function name after trailing } */
60 { TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) },
61 /* Include sleep time (scheduled out) between entry and return */
62 { TRACER_OPT(sleep-time, TRACE_GRAPH_SLEEP_TIME) },
63
64#ifdef CONFIG_FUNCTION_PROFILER
65 /* Include time within nested functions */
66 { TRACER_OPT(graph-time, TRACE_GRAPH_GRAPH_TIME) },
67#endif
68
69 { } /* Empty entry */
70};
71
72static struct tracer_flags tracer_flags = {
73 /* Don't display overruns, proc, or tail by default */
74 .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
75 TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS |
76 TRACE_GRAPH_SLEEP_TIME | TRACE_GRAPH_GRAPH_TIME,
77 .opts = trace_opts
78};
79
80static struct trace_array *graph_array;
81
82/*
83 * DURATION column is being also used to display IRQ signs,
84 * following values are used by print_graph_irq and others
85 * to fill in space into DURATION column.
86 */
87enum {
88 FLAGS_FILL_FULL = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT,
89 FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT,
90 FLAGS_FILL_END = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT,
91};
92
93static void
94print_graph_duration(struct trace_array *tr, unsigned long long duration,
95 struct trace_seq *s, u32 flags);
96
97int __trace_graph_entry(struct trace_array *tr,
98 struct ftrace_graph_ent *trace,
99 unsigned int trace_ctx)
100{
101 struct trace_event_call *call = &event_funcgraph_entry;
102 struct ring_buffer_event *event;
103 struct trace_buffer *buffer = tr->array_buffer.buffer;
104 struct ftrace_graph_ent_entry *entry;
105
106 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
107 sizeof(*entry), trace_ctx);
108 if (!event)
109 return 0;
110 entry = ring_buffer_event_data(event);
111 entry->graph_ent = *trace;
112 if (!call_filter_check_discard(call, entry, buffer, event))
113 trace_buffer_unlock_commit_nostack(buffer, event);
114
115 return 1;
116}
117
118static inline int ftrace_graph_ignore_irqs(void)
119{
120 if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
121 return 0;
122
123 return in_hardirq();
124}
125
126int trace_graph_entry(struct ftrace_graph_ent *trace)
127{
128 struct trace_array *tr = graph_array;
129 struct trace_array_cpu *data;
130 unsigned long flags;
131 unsigned int trace_ctx;
132 long disabled;
133 int ret;
134 int cpu;
135
136 if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT))
137 return 0;
138
139 /*
140 * Do not trace a function if it's filtered by set_graph_notrace.
141 * Make the index of ret stack negative to indicate that it should
142 * ignore further functions. But it needs its own ret stack entry
143 * to recover the original index in order to continue tracing after
144 * returning from the function.
145 */
146 if (ftrace_graph_notrace_addr(trace->func)) {
147 trace_recursion_set(TRACE_GRAPH_NOTRACE_BIT);
148 /*
149 * Need to return 1 to have the return called
150 * that will clear the NOTRACE bit.
151 */
152 return 1;
153 }
154
155 if (!ftrace_trace_task(tr))
156 return 0;
157
158 if (ftrace_graph_ignore_func(trace))
159 return 0;
160
161 if (ftrace_graph_ignore_irqs())
162 return 0;
163
164 /*
165 * Stop here if tracing_threshold is set. We only write function return
166 * events to the ring buffer.
167 */
168 if (tracing_thresh)
169 return 1;
170
171 local_irq_save(flags);
172 cpu = raw_smp_processor_id();
173 data = per_cpu_ptr(tr->array_buffer.data, cpu);
174 disabled = atomic_inc_return(&data->disabled);
175 if (likely(disabled == 1)) {
176 trace_ctx = tracing_gen_ctx_flags(flags);
177 ret = __trace_graph_entry(tr, trace, trace_ctx);
178 } else {
179 ret = 0;
180 }
181
182 atomic_dec(&data->disabled);
183 local_irq_restore(flags);
184
185 return ret;
186}
187
188static void
189__trace_graph_function(struct trace_array *tr,
190 unsigned long ip, unsigned int trace_ctx)
191{
192 u64 time = trace_clock_local();
193 struct ftrace_graph_ent ent = {
194 .func = ip,
195 .depth = 0,
196 };
197 struct ftrace_graph_ret ret = {
198 .func = ip,
199 .depth = 0,
200 .calltime = time,
201 .rettime = time,
202 };
203
204 __trace_graph_entry(tr, &ent, trace_ctx);
205 __trace_graph_return(tr, &ret, trace_ctx);
206}
207
208void
209trace_graph_function(struct trace_array *tr,
210 unsigned long ip, unsigned long parent_ip,
211 unsigned int trace_ctx)
212{
213 __trace_graph_function(tr, ip, trace_ctx);
214}
215
216void __trace_graph_return(struct trace_array *tr,
217 struct ftrace_graph_ret *trace,
218 unsigned int trace_ctx)
219{
220 struct trace_event_call *call = &event_funcgraph_exit;
221 struct ring_buffer_event *event;
222 struct trace_buffer *buffer = tr->array_buffer.buffer;
223 struct ftrace_graph_ret_entry *entry;
224
225 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
226 sizeof(*entry), trace_ctx);
227 if (!event)
228 return;
229 entry = ring_buffer_event_data(event);
230 entry->ret = *trace;
231 if (!call_filter_check_discard(call, entry, buffer, event))
232 trace_buffer_unlock_commit_nostack(buffer, event);
233}
234
235void trace_graph_return(struct ftrace_graph_ret *trace)
236{
237 struct trace_array *tr = graph_array;
238 struct trace_array_cpu *data;
239 unsigned long flags;
240 unsigned int trace_ctx;
241 long disabled;
242 int cpu;
243
244 ftrace_graph_addr_finish(trace);
245
246 if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
247 trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
248 return;
249 }
250
251 local_irq_save(flags);
252 cpu = raw_smp_processor_id();
253 data = per_cpu_ptr(tr->array_buffer.data, cpu);
254 disabled = atomic_inc_return(&data->disabled);
255 if (likely(disabled == 1)) {
256 trace_ctx = tracing_gen_ctx_flags(flags);
257 __trace_graph_return(tr, trace, trace_ctx);
258 }
259 atomic_dec(&data->disabled);
260 local_irq_restore(flags);
261}
262
263void set_graph_array(struct trace_array *tr)
264{
265 graph_array = tr;
266
267 /* Make graph_array visible before we start tracing */
268
269 smp_mb();
270}
271
272static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
273{
274 ftrace_graph_addr_finish(trace);
275
276 if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
277 trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
278 return;
279 }
280
281 if (tracing_thresh &&
282 (trace->rettime - trace->calltime < tracing_thresh))
283 return;
284 else
285 trace_graph_return(trace);
286}
287
288static struct fgraph_ops funcgraph_thresh_ops = {
289 .entryfunc = &trace_graph_entry,
290 .retfunc = &trace_graph_thresh_return,
291};
292
293static struct fgraph_ops funcgraph_ops = {
294 .entryfunc = &trace_graph_entry,
295 .retfunc = &trace_graph_return,
296};
297
298static int graph_trace_init(struct trace_array *tr)
299{
300 int ret;
301
302 set_graph_array(tr);
303 if (tracing_thresh)
304 ret = register_ftrace_graph(&funcgraph_thresh_ops);
305 else
306 ret = register_ftrace_graph(&funcgraph_ops);
307 if (ret)
308 return ret;
309 tracing_start_cmdline_record();
310
311 return 0;
312}
313
314static void graph_trace_reset(struct trace_array *tr)
315{
316 tracing_stop_cmdline_record();
317 if (tracing_thresh)
318 unregister_ftrace_graph(&funcgraph_thresh_ops);
319 else
320 unregister_ftrace_graph(&funcgraph_ops);
321}
322
323static int graph_trace_update_thresh(struct trace_array *tr)
324{
325 graph_trace_reset(tr);
326 return graph_trace_init(tr);
327}
328
329static int max_bytes_for_cpu;
330
331static void print_graph_cpu(struct trace_seq *s, int cpu)
332{
333 /*
334 * Start with a space character - to make it stand out
335 * to the right a bit when trace output is pasted into
336 * email:
337 */
338 trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
339}
340
341#define TRACE_GRAPH_PROCINFO_LENGTH 14
342
343static void print_graph_proc(struct trace_seq *s, pid_t pid)
344{
345 char comm[TASK_COMM_LEN];
346 /* sign + log10(MAX_INT) + '\0' */
347 char pid_str[11];
348 int spaces = 0;
349 int len;
350 int i;
351
352 trace_find_cmdline(pid, comm);
353 comm[7] = '\0';
354 sprintf(pid_str, "%d", pid);
355
356 /* 1 stands for the "-" character */
357 len = strlen(comm) + strlen(pid_str) + 1;
358
359 if (len < TRACE_GRAPH_PROCINFO_LENGTH)
360 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
361
362 /* First spaces to align center */
363 for (i = 0; i < spaces / 2; i++)
364 trace_seq_putc(s, ' ');
365
366 trace_seq_printf(s, "%s-%s", comm, pid_str);
367
368 /* Last spaces to align center */
369 for (i = 0; i < spaces - (spaces / 2); i++)
370 trace_seq_putc(s, ' ');
371}
372
373
374static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
375{
376 trace_seq_putc(s, ' ');
377 trace_print_lat_fmt(s, entry);
378 trace_seq_puts(s, " | ");
379}
380
381/* If the pid changed since the last trace, output this event */
382static void
383verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
384{
385 pid_t prev_pid;
386 pid_t *last_pid;
387
388 if (!data)
389 return;
390
391 last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
392
393 if (*last_pid == pid)
394 return;
395
396 prev_pid = *last_pid;
397 *last_pid = pid;
398
399 if (prev_pid == -1)
400 return;
401/*
402 * Context-switch trace line:
403
404 ------------------------------------------
405 | 1) migration/0--1 => sshd-1755
406 ------------------------------------------
407
408 */
409 trace_seq_puts(s, " ------------------------------------------\n");
410 print_graph_cpu(s, cpu);
411 print_graph_proc(s, prev_pid);
412 trace_seq_puts(s, " => ");
413 print_graph_proc(s, pid);
414 trace_seq_puts(s, "\n ------------------------------------------\n\n");
415}
416
417static struct ftrace_graph_ret_entry *
418get_return_for_leaf(struct trace_iterator *iter,
419 struct ftrace_graph_ent_entry *curr)
420{
421 struct fgraph_data *data = iter->private;
422 struct ring_buffer_iter *ring_iter = NULL;
423 struct ring_buffer_event *event;
424 struct ftrace_graph_ret_entry *next;
425
426 /*
427 * If the previous output failed to write to the seq buffer,
428 * then we just reuse the data from before.
429 */
430 if (data && data->failed) {
431 curr = &data->ent;
432 next = &data->ret;
433 } else {
434
435 ring_iter = trace_buffer_iter(iter, iter->cpu);
436
437 /* First peek to compare current entry and the next one */
438 if (ring_iter)
439 event = ring_buffer_iter_peek(ring_iter, NULL);
440 else {
441 /*
442 * We need to consume the current entry to see
443 * the next one.
444 */
445 ring_buffer_consume(iter->array_buffer->buffer, iter->cpu,
446 NULL, NULL);
447 event = ring_buffer_peek(iter->array_buffer->buffer, iter->cpu,
448 NULL, NULL);
449 }
450
451 if (!event)
452 return NULL;
453
454 next = ring_buffer_event_data(event);
455
456 if (data) {
457 /*
458 * Save current and next entries for later reference
459 * if the output fails.
460 */
461 data->ent = *curr;
462 /*
463 * If the next event is not a return type, then
464 * we only care about what type it is. Otherwise we can
465 * safely copy the entire event.
466 */
467 if (next->ent.type == TRACE_GRAPH_RET)
468 data->ret = *next;
469 else
470 data->ret.ent.type = next->ent.type;
471 }
472 }
473
474 if (next->ent.type != TRACE_GRAPH_RET)
475 return NULL;
476
477 if (curr->ent.pid != next->ent.pid ||
478 curr->graph_ent.func != next->ret.func)
479 return NULL;
480
481 /* this is a leaf, now advance the iterator */
482 if (ring_iter)
483 ring_buffer_iter_advance(ring_iter);
484
485 return next;
486}
487
488static void print_graph_abs_time(u64 t, struct trace_seq *s)
489{
490 unsigned long usecs_rem;
491
492 usecs_rem = do_div(t, NSEC_PER_SEC);
493 usecs_rem /= 1000;
494
495 trace_seq_printf(s, "%5lu.%06lu | ",
496 (unsigned long)t, usecs_rem);
497}
498
499static void
500print_graph_rel_time(struct trace_iterator *iter, struct trace_seq *s)
501{
502 unsigned long long usecs;
503
504 usecs = iter->ts - iter->array_buffer->time_start;
505 do_div(usecs, NSEC_PER_USEC);
506
507 trace_seq_printf(s, "%9llu us | ", usecs);
508}
509
510static void
511print_graph_irq(struct trace_iterator *iter, unsigned long addr,
512 enum trace_type type, int cpu, pid_t pid, u32 flags)
513{
514 struct trace_array *tr = iter->tr;
515 struct trace_seq *s = &iter->seq;
516 struct trace_entry *ent = iter->ent;
517
518 if (addr < (unsigned long)__irqentry_text_start ||
519 addr >= (unsigned long)__irqentry_text_end)
520 return;
521
522 if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
523 /* Absolute time */
524 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
525 print_graph_abs_time(iter->ts, s);
526
527 /* Relative time */
528 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
529 print_graph_rel_time(iter, s);
530
531 /* Cpu */
532 if (flags & TRACE_GRAPH_PRINT_CPU)
533 print_graph_cpu(s, cpu);
534
535 /* Proc */
536 if (flags & TRACE_GRAPH_PRINT_PROC) {
537 print_graph_proc(s, pid);
538 trace_seq_puts(s, " | ");
539 }
540
541 /* Latency format */
542 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
543 print_graph_lat_fmt(s, ent);
544 }
545
546 /* No overhead */
547 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_START);
548
549 if (type == TRACE_GRAPH_ENT)
550 trace_seq_puts(s, "==========>");
551 else
552 trace_seq_puts(s, "<==========");
553
554 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_END);
555 trace_seq_putc(s, '\n');
556}
557
558void
559trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
560{
561 unsigned long nsecs_rem = do_div(duration, 1000);
562 /* log10(ULONG_MAX) + '\0' */
563 char usecs_str[21];
564 char nsecs_str[5];
565 int len;
566 int i;
567
568 sprintf(usecs_str, "%lu", (unsigned long) duration);
569
570 /* Print msecs */
571 trace_seq_printf(s, "%s", usecs_str);
572
573 len = strlen(usecs_str);
574
575 /* Print nsecs (we don't want to exceed 7 numbers) */
576 if (len < 7) {
577 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
578
579 snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
580 trace_seq_printf(s, ".%s", nsecs_str);
581 len += strlen(nsecs_str) + 1;
582 }
583
584 trace_seq_puts(s, " us ");
585
586 /* Print remaining spaces to fit the row's width */
587 for (i = len; i < 8; i++)
588 trace_seq_putc(s, ' ');
589}
590
591static void
592print_graph_duration(struct trace_array *tr, unsigned long long duration,
593 struct trace_seq *s, u32 flags)
594{
595 if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
596 !(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
597 return;
598
599 /* No real adata, just filling the column with spaces */
600 switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
601 case FLAGS_FILL_FULL:
602 trace_seq_puts(s, " | ");
603 return;
604 case FLAGS_FILL_START:
605 trace_seq_puts(s, " ");
606 return;
607 case FLAGS_FILL_END:
608 trace_seq_puts(s, " |");
609 return;
610 }
611
612 /* Signal a overhead of time execution to the output */
613 if (flags & TRACE_GRAPH_PRINT_OVERHEAD)
614 trace_seq_printf(s, "%c ", trace_find_mark(duration));
615 else
616 trace_seq_puts(s, " ");
617
618 trace_print_graph_duration(duration, s);
619 trace_seq_puts(s, "| ");
620}
621
622/* Case of a leaf function on its call entry */
623static enum print_line_t
624print_graph_entry_leaf(struct trace_iterator *iter,
625 struct ftrace_graph_ent_entry *entry,
626 struct ftrace_graph_ret_entry *ret_entry,
627 struct trace_seq *s, u32 flags)
628{
629 struct fgraph_data *data = iter->private;
630 struct trace_array *tr = iter->tr;
631 struct ftrace_graph_ret *graph_ret;
632 struct ftrace_graph_ent *call;
633 unsigned long long duration;
634 int cpu = iter->cpu;
635 int i;
636
637 graph_ret = &ret_entry->ret;
638 call = &entry->graph_ent;
639 duration = graph_ret->rettime - graph_ret->calltime;
640
641 if (data) {
642 struct fgraph_cpu_data *cpu_data;
643
644 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
645
646 /*
647 * Comments display at + 1 to depth. Since
648 * this is a leaf function, keep the comments
649 * equal to this depth.
650 */
651 cpu_data->depth = call->depth - 1;
652
653 /* No need to keep this function around for this depth */
654 if (call->depth < FTRACE_RETFUNC_DEPTH &&
655 !WARN_ON_ONCE(call->depth < 0))
656 cpu_data->enter_funcs[call->depth] = 0;
657 }
658
659 /* Overhead and duration */
660 print_graph_duration(tr, duration, s, flags);
661
662 /* Function */
663 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
664 trace_seq_putc(s, ' ');
665
666 trace_seq_printf(s, "%ps();\n", (void *)call->func);
667
668 print_graph_irq(iter, graph_ret->func, TRACE_GRAPH_RET,
669 cpu, iter->ent->pid, flags);
670
671 return trace_handle_return(s);
672}
673
674static enum print_line_t
675print_graph_entry_nested(struct trace_iterator *iter,
676 struct ftrace_graph_ent_entry *entry,
677 struct trace_seq *s, int cpu, u32 flags)
678{
679 struct ftrace_graph_ent *call = &entry->graph_ent;
680 struct fgraph_data *data = iter->private;
681 struct trace_array *tr = iter->tr;
682 int i;
683
684 if (data) {
685 struct fgraph_cpu_data *cpu_data;
686 int cpu = iter->cpu;
687
688 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
689 cpu_data->depth = call->depth;
690
691 /* Save this function pointer to see if the exit matches */
692 if (call->depth < FTRACE_RETFUNC_DEPTH &&
693 !WARN_ON_ONCE(call->depth < 0))
694 cpu_data->enter_funcs[call->depth] = call->func;
695 }
696
697 /* No time */
698 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
699
700 /* Function */
701 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
702 trace_seq_putc(s, ' ');
703
704 trace_seq_printf(s, "%ps() {\n", (void *)call->func);
705
706 if (trace_seq_has_overflowed(s))
707 return TRACE_TYPE_PARTIAL_LINE;
708
709 /*
710 * we already consumed the current entry to check the next one
711 * and see if this is a leaf.
712 */
713 return TRACE_TYPE_NO_CONSUME;
714}
715
716static void
717print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
718 int type, unsigned long addr, u32 flags)
719{
720 struct fgraph_data *data = iter->private;
721 struct trace_entry *ent = iter->ent;
722 struct trace_array *tr = iter->tr;
723 int cpu = iter->cpu;
724
725 /* Pid */
726 verif_pid(s, ent->pid, cpu, data);
727
728 if (type)
729 /* Interrupt */
730 print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
731
732 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
733 return;
734
735 /* Absolute time */
736 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
737 print_graph_abs_time(iter->ts, s);
738
739 /* Relative time */
740 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
741 print_graph_rel_time(iter, s);
742
743 /* Cpu */
744 if (flags & TRACE_GRAPH_PRINT_CPU)
745 print_graph_cpu(s, cpu);
746
747 /* Proc */
748 if (flags & TRACE_GRAPH_PRINT_PROC) {
749 print_graph_proc(s, ent->pid);
750 trace_seq_puts(s, " | ");
751 }
752
753 /* Latency format */
754 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
755 print_graph_lat_fmt(s, ent);
756
757 return;
758}
759
760/*
761 * Entry check for irq code
762 *
763 * returns 1 if
764 * - we are inside irq code
765 * - we just entered irq code
766 *
767 * returns 0 if
768 * - funcgraph-interrupts option is set
769 * - we are not inside irq code
770 */
771static int
772check_irq_entry(struct trace_iterator *iter, u32 flags,
773 unsigned long addr, int depth)
774{
775 int cpu = iter->cpu;
776 int *depth_irq;
777 struct fgraph_data *data = iter->private;
778
779 /*
780 * If we are either displaying irqs, or we got called as
781 * a graph event and private data does not exist,
782 * then we bypass the irq check.
783 */
784 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
785 (!data))
786 return 0;
787
788 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
789
790 /*
791 * We are inside the irq code
792 */
793 if (*depth_irq >= 0)
794 return 1;
795
796 if ((addr < (unsigned long)__irqentry_text_start) ||
797 (addr >= (unsigned long)__irqentry_text_end))
798 return 0;
799
800 /*
801 * We are entering irq code.
802 */
803 *depth_irq = depth;
804 return 1;
805}
806
807/*
808 * Return check for irq code
809 *
810 * returns 1 if
811 * - we are inside irq code
812 * - we just left irq code
813 *
814 * returns 0 if
815 * - funcgraph-interrupts option is set
816 * - we are not inside irq code
817 */
818static int
819check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
820{
821 int cpu = iter->cpu;
822 int *depth_irq;
823 struct fgraph_data *data = iter->private;
824
825 /*
826 * If we are either displaying irqs, or we got called as
827 * a graph event and private data does not exist,
828 * then we bypass the irq check.
829 */
830 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
831 (!data))
832 return 0;
833
834 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
835
836 /*
837 * We are not inside the irq code.
838 */
839 if (*depth_irq == -1)
840 return 0;
841
842 /*
843 * We are inside the irq code, and this is returning entry.
844 * Let's not trace it and clear the entry depth, since
845 * we are out of irq code.
846 *
847 * This condition ensures that we 'leave the irq code' once
848 * we are out of the entry depth. Thus protecting us from
849 * the RETURN entry loss.
850 */
851 if (*depth_irq >= depth) {
852 *depth_irq = -1;
853 return 1;
854 }
855
856 /*
857 * We are inside the irq code, and this is not the entry.
858 */
859 return 1;
860}
861
862static enum print_line_t
863print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
864 struct trace_iterator *iter, u32 flags)
865{
866 struct fgraph_data *data = iter->private;
867 struct ftrace_graph_ent *call = &field->graph_ent;
868 struct ftrace_graph_ret_entry *leaf_ret;
869 static enum print_line_t ret;
870 int cpu = iter->cpu;
871
872 if (check_irq_entry(iter, flags, call->func, call->depth))
873 return TRACE_TYPE_HANDLED;
874
875 print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags);
876
877 leaf_ret = get_return_for_leaf(iter, field);
878 if (leaf_ret)
879 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
880 else
881 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
882
883 if (data) {
884 /*
885 * If we failed to write our output, then we need to make
886 * note of it. Because we already consumed our entry.
887 */
888 if (s->full) {
889 data->failed = 1;
890 data->cpu = cpu;
891 } else
892 data->failed = 0;
893 }
894
895 return ret;
896}
897
898static enum print_line_t
899print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
900 struct trace_entry *ent, struct trace_iterator *iter,
901 u32 flags)
902{
903 unsigned long long duration = trace->rettime - trace->calltime;
904 struct fgraph_data *data = iter->private;
905 struct trace_array *tr = iter->tr;
906 pid_t pid = ent->pid;
907 int cpu = iter->cpu;
908 int func_match = 1;
909 int i;
910
911 if (check_irq_return(iter, flags, trace->depth))
912 return TRACE_TYPE_HANDLED;
913
914 if (data) {
915 struct fgraph_cpu_data *cpu_data;
916 int cpu = iter->cpu;
917
918 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
919
920 /*
921 * Comments display at + 1 to depth. This is the
922 * return from a function, we now want the comments
923 * to display at the same level of the bracket.
924 */
925 cpu_data->depth = trace->depth - 1;
926
927 if (trace->depth < FTRACE_RETFUNC_DEPTH &&
928 !WARN_ON_ONCE(trace->depth < 0)) {
929 if (cpu_data->enter_funcs[trace->depth] != trace->func)
930 func_match = 0;
931 cpu_data->enter_funcs[trace->depth] = 0;
932 }
933 }
934
935 print_graph_prologue(iter, s, 0, 0, flags);
936
937 /* Overhead and duration */
938 print_graph_duration(tr, duration, s, flags);
939
940 /* Closing brace */
941 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++)
942 trace_seq_putc(s, ' ');
943
944 /*
945 * If the return function does not have a matching entry,
946 * then the entry was lost. Instead of just printing
947 * the '}' and letting the user guess what function this
948 * belongs to, write out the function name. Always do
949 * that if the funcgraph-tail option is enabled.
950 */
951 if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL))
952 trace_seq_puts(s, "}\n");
953 else
954 trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
955
956 /* Overrun */
957 if (flags & TRACE_GRAPH_PRINT_OVERRUN)
958 trace_seq_printf(s, " (Overruns: %u)\n",
959 trace->overrun);
960
961 print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
962 cpu, pid, flags);
963
964 return trace_handle_return(s);
965}
966
967static enum print_line_t
968print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
969 struct trace_iterator *iter, u32 flags)
970{
971 struct trace_array *tr = iter->tr;
972 unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
973 struct fgraph_data *data = iter->private;
974 struct trace_event *event;
975 int depth = 0;
976 int ret;
977 int i;
978
979 if (data)
980 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
981
982 print_graph_prologue(iter, s, 0, 0, flags);
983
984 /* No time */
985 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
986
987 /* Indentation */
988 if (depth > 0)
989 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++)
990 trace_seq_putc(s, ' ');
991
992 /* The comment */
993 trace_seq_puts(s, "/* ");
994
995 switch (iter->ent->type) {
996 case TRACE_BPUTS:
997 ret = trace_print_bputs_msg_only(iter);
998 if (ret != TRACE_TYPE_HANDLED)
999 return ret;
1000 break;
1001 case TRACE_BPRINT:
1002 ret = trace_print_bprintk_msg_only(iter);
1003 if (ret != TRACE_TYPE_HANDLED)
1004 return ret;
1005 break;
1006 case TRACE_PRINT:
1007 ret = trace_print_printk_msg_only(iter);
1008 if (ret != TRACE_TYPE_HANDLED)
1009 return ret;
1010 break;
1011 default:
1012 event = ftrace_find_event(ent->type);
1013 if (!event)
1014 return TRACE_TYPE_UNHANDLED;
1015
1016 ret = event->funcs->trace(iter, sym_flags, event);
1017 if (ret != TRACE_TYPE_HANDLED)
1018 return ret;
1019 }
1020
1021 if (trace_seq_has_overflowed(s))
1022 goto out;
1023
1024 /* Strip ending newline */
1025 if (s->buffer[s->seq.len - 1] == '\n') {
1026 s->buffer[s->seq.len - 1] = '\0';
1027 s->seq.len--;
1028 }
1029
1030 trace_seq_puts(s, " */\n");
1031 out:
1032 return trace_handle_return(s);
1033}
1034
1035
1036enum print_line_t
1037print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1038{
1039 struct ftrace_graph_ent_entry *field;
1040 struct fgraph_data *data = iter->private;
1041 struct trace_entry *entry = iter->ent;
1042 struct trace_seq *s = &iter->seq;
1043 int cpu = iter->cpu;
1044 int ret;
1045
1046 if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1047 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1048 return TRACE_TYPE_HANDLED;
1049 }
1050
1051 /*
1052 * If the last output failed, there's a possibility we need
1053 * to print out the missing entry which would never go out.
1054 */
1055 if (data && data->failed) {
1056 field = &data->ent;
1057 iter->cpu = data->cpu;
1058 ret = print_graph_entry(field, s, iter, flags);
1059 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1060 per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1061 ret = TRACE_TYPE_NO_CONSUME;
1062 }
1063 iter->cpu = cpu;
1064 return ret;
1065 }
1066
1067 switch (entry->type) {
1068 case TRACE_GRAPH_ENT: {
1069 /*
1070 * print_graph_entry() may consume the current event,
1071 * thus @field may become invalid, so we need to save it.
1072 * sizeof(struct ftrace_graph_ent_entry) is very small,
1073 * it can be safely saved at the stack.
1074 */
1075 struct ftrace_graph_ent_entry saved;
1076 trace_assign_type(field, entry);
1077 saved = *field;
1078 return print_graph_entry(&saved, s, iter, flags);
1079 }
1080 case TRACE_GRAPH_RET: {
1081 struct ftrace_graph_ret_entry *field;
1082 trace_assign_type(field, entry);
1083 return print_graph_return(&field->ret, s, entry, iter, flags);
1084 }
1085 case TRACE_STACK:
1086 case TRACE_FN:
1087 /* dont trace stack and functions as comments */
1088 return TRACE_TYPE_UNHANDLED;
1089
1090 default:
1091 return print_graph_comment(s, entry, iter, flags);
1092 }
1093
1094 return TRACE_TYPE_HANDLED;
1095}
1096
1097static enum print_line_t
1098print_graph_function(struct trace_iterator *iter)
1099{
1100 return print_graph_function_flags(iter, tracer_flags.val);
1101}
1102
1103static enum print_line_t
1104print_graph_function_event(struct trace_iterator *iter, int flags,
1105 struct trace_event *event)
1106{
1107 return print_graph_function(iter);
1108}
1109
1110static void print_lat_header(struct seq_file *s, u32 flags)
1111{
1112 static const char spaces[] = " " /* 16 spaces */
1113 " " /* 4 spaces */
1114 " "; /* 17 spaces */
1115 int size = 0;
1116
1117 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1118 size += 16;
1119 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1120 size += 16;
1121 if (flags & TRACE_GRAPH_PRINT_CPU)
1122 size += 4;
1123 if (flags & TRACE_GRAPH_PRINT_PROC)
1124 size += 17;
1125
1126 seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces);
1127 seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
1128 seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1129 seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
1130 seq_printf(s, "#%.*s||| / \n", size, spaces);
1131}
1132
1133static void __print_graph_headers_flags(struct trace_array *tr,
1134 struct seq_file *s, u32 flags)
1135{
1136 int lat = tr->trace_flags & TRACE_ITER_LATENCY_FMT;
1137
1138 if (lat)
1139 print_lat_header(s, flags);
1140
1141 /* 1st line */
1142 seq_putc(s, '#');
1143 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1144 seq_puts(s, " TIME ");
1145 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1146 seq_puts(s, " REL TIME ");
1147 if (flags & TRACE_GRAPH_PRINT_CPU)
1148 seq_puts(s, " CPU");
1149 if (flags & TRACE_GRAPH_PRINT_PROC)
1150 seq_puts(s, " TASK/PID ");
1151 if (lat)
1152 seq_puts(s, "|||| ");
1153 if (flags & TRACE_GRAPH_PRINT_DURATION)
1154 seq_puts(s, " DURATION ");
1155 seq_puts(s, " FUNCTION CALLS\n");
1156
1157 /* 2nd line */
1158 seq_putc(s, '#');
1159 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1160 seq_puts(s, " | ");
1161 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1162 seq_puts(s, " | ");
1163 if (flags & TRACE_GRAPH_PRINT_CPU)
1164 seq_puts(s, " | ");
1165 if (flags & TRACE_GRAPH_PRINT_PROC)
1166 seq_puts(s, " | | ");
1167 if (lat)
1168 seq_puts(s, "|||| ");
1169 if (flags & TRACE_GRAPH_PRINT_DURATION)
1170 seq_puts(s, " | | ");
1171 seq_puts(s, " | | | |\n");
1172}
1173
1174static void print_graph_headers(struct seq_file *s)
1175{
1176 print_graph_headers_flags(s, tracer_flags.val);
1177}
1178
1179void print_graph_headers_flags(struct seq_file *s, u32 flags)
1180{
1181 struct trace_iterator *iter = s->private;
1182 struct trace_array *tr = iter->tr;
1183
1184 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
1185 return;
1186
1187 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) {
1188 /* print nothing if the buffers are empty */
1189 if (trace_empty(iter))
1190 return;
1191
1192 print_trace_header(s, iter);
1193 }
1194
1195 __print_graph_headers_flags(tr, s, flags);
1196}
1197
1198void graph_trace_open(struct trace_iterator *iter)
1199{
1200 /* pid and depth on the last trace processed */
1201 struct fgraph_data *data;
1202 gfp_t gfpflags;
1203 int cpu;
1204
1205 iter->private = NULL;
1206
1207 /* We can be called in atomic context via ftrace_dump() */
1208 gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL;
1209
1210 data = kzalloc(sizeof(*data), gfpflags);
1211 if (!data)
1212 goto out_err;
1213
1214 data->cpu_data = alloc_percpu_gfp(struct fgraph_cpu_data, gfpflags);
1215 if (!data->cpu_data)
1216 goto out_err_free;
1217
1218 for_each_possible_cpu(cpu) {
1219 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1220 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1221 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1222 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1223
1224 *pid = -1;
1225 *depth = 0;
1226 *ignore = 0;
1227 *depth_irq = -1;
1228 }
1229
1230 iter->private = data;
1231
1232 return;
1233
1234 out_err_free:
1235 kfree(data);
1236 out_err:
1237 pr_warn("function graph tracer: not enough memory\n");
1238}
1239
1240void graph_trace_close(struct trace_iterator *iter)
1241{
1242 struct fgraph_data *data = iter->private;
1243
1244 if (data) {
1245 free_percpu(data->cpu_data);
1246 kfree(data);
1247 }
1248}
1249
1250static int
1251func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
1252{
1253 if (bit == TRACE_GRAPH_PRINT_IRQS)
1254 ftrace_graph_skip_irqs = !set;
1255
1256 if (bit == TRACE_GRAPH_SLEEP_TIME)
1257 ftrace_graph_sleep_time_control(set);
1258
1259 if (bit == TRACE_GRAPH_GRAPH_TIME)
1260 ftrace_graph_graph_time_control(set);
1261
1262 return 0;
1263}
1264
1265static struct trace_event_functions graph_functions = {
1266 .trace = print_graph_function_event,
1267};
1268
1269static struct trace_event graph_trace_entry_event = {
1270 .type = TRACE_GRAPH_ENT,
1271 .funcs = &graph_functions,
1272};
1273
1274static struct trace_event graph_trace_ret_event = {
1275 .type = TRACE_GRAPH_RET,
1276 .funcs = &graph_functions
1277};
1278
1279static struct tracer graph_trace __tracer_data = {
1280 .name = "function_graph",
1281 .update_thresh = graph_trace_update_thresh,
1282 .open = graph_trace_open,
1283 .pipe_open = graph_trace_open,
1284 .close = graph_trace_close,
1285 .pipe_close = graph_trace_close,
1286 .init = graph_trace_init,
1287 .reset = graph_trace_reset,
1288 .print_line = print_graph_function,
1289 .print_header = print_graph_headers,
1290 .flags = &tracer_flags,
1291 .set_flag = func_graph_set_flag,
1292#ifdef CONFIG_FTRACE_SELFTEST
1293 .selftest = trace_selftest_startup_function_graph,
1294#endif
1295};
1296
1297
1298static ssize_t
1299graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
1300 loff_t *ppos)
1301{
1302 unsigned long val;
1303 int ret;
1304
1305 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1306 if (ret)
1307 return ret;
1308
1309 fgraph_max_depth = val;
1310
1311 *ppos += cnt;
1312
1313 return cnt;
1314}
1315
1316static ssize_t
1317graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
1318 loff_t *ppos)
1319{
1320 char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/
1321 int n;
1322
1323 n = sprintf(buf, "%d\n", fgraph_max_depth);
1324
1325 return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
1326}
1327
1328static const struct file_operations graph_depth_fops = {
1329 .open = tracing_open_generic,
1330 .write = graph_depth_write,
1331 .read = graph_depth_read,
1332 .llseek = generic_file_llseek,
1333};
1334
1335static __init int init_graph_tracefs(void)
1336{
1337 int ret;
1338
1339 ret = tracing_init_dentry();
1340 if (ret)
1341 return 0;
1342
1343 trace_create_file("max_graph_depth", TRACE_MODE_WRITE, NULL,
1344 NULL, &graph_depth_fops);
1345
1346 return 0;
1347}
1348fs_initcall(init_graph_tracefs);
1349
1350static __init int init_graph_trace(void)
1351{
1352 max_bytes_for_cpu = snprintf(NULL, 0, "%u", nr_cpu_ids - 1);
1353
1354 if (!register_trace_event(&graph_trace_entry_event)) {
1355 pr_warn("Warning: could not register graph trace events\n");
1356 return 1;
1357 }
1358
1359 if (!register_trace_event(&graph_trace_ret_event)) {
1360 pr_warn("Warning: could not register graph trace events\n");
1361 return 1;
1362 }
1363
1364 return register_tracer(&graph_trace);
1365}
1366
1367core_initcall(init_graph_trace);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 *
4 * Function graph tracer.
5 * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
6 * Mostly borrowed from function tracer which
7 * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
8 *
9 */
10#include <linux/uaccess.h>
11#include <linux/ftrace.h>
12#include <linux/interrupt.h>
13#include <linux/slab.h>
14#include <linux/fs.h>
15
16#include "trace.h"
17#include "trace_output.h"
18
19/* When set, irq functions will be ignored */
20static int ftrace_graph_skip_irqs;
21
22struct fgraph_cpu_data {
23 pid_t last_pid;
24 int depth;
25 int depth_irq;
26 int ignore;
27 unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH];
28};
29
30struct fgraph_data {
31 struct fgraph_cpu_data __percpu *cpu_data;
32
33 /* Place to preserve last processed entry. */
34 union {
35 struct ftrace_graph_ent_entry ent;
36 struct fgraph_retaddr_ent_entry rent;
37 } ent;
38 struct ftrace_graph_ret_entry ret;
39 int failed;
40 int cpu;
41};
42
43#define TRACE_GRAPH_INDENT 2
44
45unsigned int fgraph_max_depth;
46
47static struct tracer_opt trace_opts[] = {
48 /* Display overruns? (for self-debug purpose) */
49 { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
50 /* Display CPU ? */
51 { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
52 /* Display Overhead ? */
53 { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
54 /* Display proc name/pid */
55 { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
56 /* Display duration of execution */
57 { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
58 /* Display absolute time of an entry */
59 { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
60 /* Display interrupts */
61 { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
62 /* Display function name after trailing } */
63 { TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) },
64#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
65 /* Display function return value ? */
66 { TRACER_OPT(funcgraph-retval, TRACE_GRAPH_PRINT_RETVAL) },
67 /* Display function return value in hexadecimal format ? */
68 { TRACER_OPT(funcgraph-retval-hex, TRACE_GRAPH_PRINT_RETVAL_HEX) },
69#endif
70#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
71 /* Display function return address ? */
72 { TRACER_OPT(funcgraph-retaddr, TRACE_GRAPH_PRINT_RETADDR) },
73#endif
74 /* Include sleep time (scheduled out) between entry and return */
75 { TRACER_OPT(sleep-time, TRACE_GRAPH_SLEEP_TIME) },
76
77#ifdef CONFIG_FUNCTION_PROFILER
78 /* Include time within nested functions */
79 { TRACER_OPT(graph-time, TRACE_GRAPH_GRAPH_TIME) },
80#endif
81
82 { } /* Empty entry */
83};
84
85static struct tracer_flags tracer_flags = {
86 /* Don't display overruns, proc, or tail by default */
87 .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
88 TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS |
89 TRACE_GRAPH_SLEEP_TIME | TRACE_GRAPH_GRAPH_TIME,
90 .opts = trace_opts
91};
92
93static bool tracer_flags_is_set(u32 flags)
94{
95 return (tracer_flags.val & flags) == flags;
96}
97
98/*
99 * DURATION column is being also used to display IRQ signs,
100 * following values are used by print_graph_irq and others
101 * to fill in space into DURATION column.
102 */
103enum {
104 FLAGS_FILL_FULL = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT,
105 FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT,
106 FLAGS_FILL_END = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT,
107};
108
109static void
110print_graph_duration(struct trace_array *tr, unsigned long long duration,
111 struct trace_seq *s, u32 flags);
112
113int __trace_graph_entry(struct trace_array *tr,
114 struct ftrace_graph_ent *trace,
115 unsigned int trace_ctx)
116{
117 struct ring_buffer_event *event;
118 struct trace_buffer *buffer = tr->array_buffer.buffer;
119 struct ftrace_graph_ent_entry *entry;
120
121 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
122 sizeof(*entry), trace_ctx);
123 if (!event)
124 return 0;
125 entry = ring_buffer_event_data(event);
126 entry->graph_ent = *trace;
127 trace_buffer_unlock_commit_nostack(buffer, event);
128
129 return 1;
130}
131
132#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
133int __trace_graph_retaddr_entry(struct trace_array *tr,
134 struct ftrace_graph_ent *trace,
135 unsigned int trace_ctx,
136 unsigned long retaddr)
137{
138 struct ring_buffer_event *event;
139 struct trace_buffer *buffer = tr->array_buffer.buffer;
140 struct fgraph_retaddr_ent_entry *entry;
141
142 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RETADDR_ENT,
143 sizeof(*entry), trace_ctx);
144 if (!event)
145 return 0;
146 entry = ring_buffer_event_data(event);
147 entry->graph_ent.func = trace->func;
148 entry->graph_ent.depth = trace->depth;
149 entry->graph_ent.retaddr = retaddr;
150 trace_buffer_unlock_commit_nostack(buffer, event);
151
152 return 1;
153}
154#else
155int __trace_graph_retaddr_entry(struct trace_array *tr,
156 struct ftrace_graph_ent *trace,
157 unsigned int trace_ctx,
158 unsigned long retaddr)
159{
160 return 1;
161}
162#endif
163
164static inline int ftrace_graph_ignore_irqs(void)
165{
166 if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
167 return 0;
168
169 return in_hardirq();
170}
171
172struct fgraph_times {
173 unsigned long long calltime;
174 unsigned long long sleeptime; /* may be optional! */
175};
176
177int trace_graph_entry(struct ftrace_graph_ent *trace,
178 struct fgraph_ops *gops)
179{
180 unsigned long *task_var = fgraph_get_task_var(gops);
181 struct trace_array *tr = gops->private;
182 struct trace_array_cpu *data;
183 struct fgraph_times *ftimes;
184 unsigned long flags;
185 unsigned int trace_ctx;
186 long disabled;
187 int ret;
188 int cpu;
189
190 if (*task_var & TRACE_GRAPH_NOTRACE)
191 return 0;
192
193 /*
194 * Do not trace a function if it's filtered by set_graph_notrace.
195 * Make the index of ret stack negative to indicate that it should
196 * ignore further functions. But it needs its own ret stack entry
197 * to recover the original index in order to continue tracing after
198 * returning from the function.
199 */
200 if (ftrace_graph_notrace_addr(trace->func)) {
201 *task_var |= TRACE_GRAPH_NOTRACE;
202 /*
203 * Need to return 1 to have the return called
204 * that will clear the NOTRACE bit.
205 */
206 return 1;
207 }
208
209 if (!ftrace_trace_task(tr))
210 return 0;
211
212 if (ftrace_graph_ignore_func(gops, trace))
213 return 0;
214
215 if (ftrace_graph_ignore_irqs())
216 return 0;
217
218 if (fgraph_sleep_time) {
219 /* Only need to record the calltime */
220 ftimes = fgraph_reserve_data(gops->idx, sizeof(ftimes->calltime));
221 } else {
222 ftimes = fgraph_reserve_data(gops->idx, sizeof(*ftimes));
223 if (ftimes)
224 ftimes->sleeptime = current->ftrace_sleeptime;
225 }
226 if (!ftimes)
227 return 0;
228
229 ftimes->calltime = trace_clock_local();
230
231 /*
232 * Stop here if tracing_threshold is set. We only write function return
233 * events to the ring buffer.
234 */
235 if (tracing_thresh)
236 return 1;
237
238 local_irq_save(flags);
239 cpu = raw_smp_processor_id();
240 data = per_cpu_ptr(tr->array_buffer.data, cpu);
241 disabled = atomic_inc_return(&data->disabled);
242 if (likely(disabled == 1)) {
243 trace_ctx = tracing_gen_ctx_flags(flags);
244 if (unlikely(IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) &&
245 tracer_flags_is_set(TRACE_GRAPH_PRINT_RETADDR))) {
246 unsigned long retaddr = ftrace_graph_top_ret_addr(current);
247
248 ret = __trace_graph_retaddr_entry(tr, trace, trace_ctx, retaddr);
249 } else
250 ret = __trace_graph_entry(tr, trace, trace_ctx);
251 } else {
252 ret = 0;
253 }
254
255 atomic_dec(&data->disabled);
256 local_irq_restore(flags);
257
258 return ret;
259}
260
261static void
262__trace_graph_function(struct trace_array *tr,
263 unsigned long ip, unsigned int trace_ctx)
264{
265 u64 time = trace_clock_local();
266 struct ftrace_graph_ent ent = {
267 .func = ip,
268 .depth = 0,
269 };
270 struct ftrace_graph_ret ret = {
271 .func = ip,
272 .depth = 0,
273 .calltime = time,
274 .rettime = time,
275 };
276
277 __trace_graph_entry(tr, &ent, trace_ctx);
278 __trace_graph_return(tr, &ret, trace_ctx);
279}
280
281void
282trace_graph_function(struct trace_array *tr,
283 unsigned long ip, unsigned long parent_ip,
284 unsigned int trace_ctx)
285{
286 __trace_graph_function(tr, ip, trace_ctx);
287}
288
289void __trace_graph_return(struct trace_array *tr,
290 struct ftrace_graph_ret *trace,
291 unsigned int trace_ctx)
292{
293 struct ring_buffer_event *event;
294 struct trace_buffer *buffer = tr->array_buffer.buffer;
295 struct ftrace_graph_ret_entry *entry;
296
297 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
298 sizeof(*entry), trace_ctx);
299 if (!event)
300 return;
301 entry = ring_buffer_event_data(event);
302 entry->ret = *trace;
303 trace_buffer_unlock_commit_nostack(buffer, event);
304}
305
306static void handle_nosleeptime(struct ftrace_graph_ret *trace,
307 struct fgraph_times *ftimes,
308 int size)
309{
310 if (fgraph_sleep_time || size < sizeof(*ftimes))
311 return;
312
313 ftimes->calltime += current->ftrace_sleeptime - ftimes->sleeptime;
314}
315
316void trace_graph_return(struct ftrace_graph_ret *trace,
317 struct fgraph_ops *gops)
318{
319 unsigned long *task_var = fgraph_get_task_var(gops);
320 struct trace_array *tr = gops->private;
321 struct trace_array_cpu *data;
322 struct fgraph_times *ftimes;
323 unsigned long flags;
324 unsigned int trace_ctx;
325 long disabled;
326 int size;
327 int cpu;
328
329 ftrace_graph_addr_finish(gops, trace);
330
331 if (*task_var & TRACE_GRAPH_NOTRACE) {
332 *task_var &= ~TRACE_GRAPH_NOTRACE;
333 return;
334 }
335
336 ftimes = fgraph_retrieve_data(gops->idx, &size);
337 if (!ftimes)
338 return;
339
340 handle_nosleeptime(trace, ftimes, size);
341
342 trace->calltime = ftimes->calltime;
343
344 local_irq_save(flags);
345 cpu = raw_smp_processor_id();
346 data = per_cpu_ptr(tr->array_buffer.data, cpu);
347 disabled = atomic_inc_return(&data->disabled);
348 if (likely(disabled == 1)) {
349 trace_ctx = tracing_gen_ctx_flags(flags);
350 __trace_graph_return(tr, trace, trace_ctx);
351 }
352 atomic_dec(&data->disabled);
353 local_irq_restore(flags);
354}
355
356static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
357 struct fgraph_ops *gops)
358{
359 struct fgraph_times *ftimes;
360 int size;
361
362 ftrace_graph_addr_finish(gops, trace);
363
364 if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
365 trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
366 return;
367 }
368
369 ftimes = fgraph_retrieve_data(gops->idx, &size);
370 if (!ftimes)
371 return;
372
373 handle_nosleeptime(trace, ftimes, size);
374
375 trace->calltime = ftimes->calltime;
376
377 if (tracing_thresh &&
378 (trace->rettime - ftimes->calltime < tracing_thresh))
379 return;
380 else
381 trace_graph_return(trace, gops);
382}
383
384static struct fgraph_ops funcgraph_ops = {
385 .entryfunc = &trace_graph_entry,
386 .retfunc = &trace_graph_return,
387};
388
389int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops)
390{
391 struct fgraph_ops *gops;
392
393 gops = kzalloc(sizeof(*gops), GFP_KERNEL);
394 if (!gops)
395 return -ENOMEM;
396
397 gops->entryfunc = &trace_graph_entry;
398 gops->retfunc = &trace_graph_return;
399
400 tr->gops = gops;
401 gops->private = tr;
402
403 fgraph_init_ops(&gops->ops, ops);
404
405 return 0;
406}
407
408void free_fgraph_ops(struct trace_array *tr)
409{
410 kfree(tr->gops);
411}
412
413__init void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops)
414{
415 tr->gops = &funcgraph_ops;
416 funcgraph_ops.private = tr;
417 fgraph_init_ops(&tr->gops->ops, ops);
418}
419
420static int graph_trace_init(struct trace_array *tr)
421{
422 int ret;
423
424 tr->gops->entryfunc = trace_graph_entry;
425
426 if (tracing_thresh)
427 tr->gops->retfunc = trace_graph_thresh_return;
428 else
429 tr->gops->retfunc = trace_graph_return;
430
431 /* Make gops functions are visible before we start tracing */
432 smp_mb();
433
434 ret = register_ftrace_graph(tr->gops);
435 if (ret)
436 return ret;
437 tracing_start_cmdline_record();
438
439 return 0;
440}
441
442static void graph_trace_reset(struct trace_array *tr)
443{
444 tracing_stop_cmdline_record();
445 unregister_ftrace_graph(tr->gops);
446}
447
448static int graph_trace_update_thresh(struct trace_array *tr)
449{
450 graph_trace_reset(tr);
451 return graph_trace_init(tr);
452}
453
454static int max_bytes_for_cpu;
455
456static void print_graph_cpu(struct trace_seq *s, int cpu)
457{
458 /*
459 * Start with a space character - to make it stand out
460 * to the right a bit when trace output is pasted into
461 * email:
462 */
463 trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
464}
465
466#define TRACE_GRAPH_PROCINFO_LENGTH 14
467
468static void print_graph_proc(struct trace_seq *s, pid_t pid)
469{
470 char comm[TASK_COMM_LEN];
471 /* sign + log10(MAX_INT) + '\0' */
472 char pid_str[11];
473 int spaces = 0;
474 int len;
475 int i;
476
477 trace_find_cmdline(pid, comm);
478 comm[7] = '\0';
479 sprintf(pid_str, "%d", pid);
480
481 /* 1 stands for the "-" character */
482 len = strlen(comm) + strlen(pid_str) + 1;
483
484 if (len < TRACE_GRAPH_PROCINFO_LENGTH)
485 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
486
487 /* First spaces to align center */
488 for (i = 0; i < spaces / 2; i++)
489 trace_seq_putc(s, ' ');
490
491 trace_seq_printf(s, "%s-%s", comm, pid_str);
492
493 /* Last spaces to align center */
494 for (i = 0; i < spaces - (spaces / 2); i++)
495 trace_seq_putc(s, ' ');
496}
497
498
499static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
500{
501 trace_seq_putc(s, ' ');
502 trace_print_lat_fmt(s, entry);
503 trace_seq_puts(s, " | ");
504}
505
506/* If the pid changed since the last trace, output this event */
507static void
508verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
509{
510 pid_t prev_pid;
511 pid_t *last_pid;
512
513 if (!data)
514 return;
515
516 last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
517
518 if (*last_pid == pid)
519 return;
520
521 prev_pid = *last_pid;
522 *last_pid = pid;
523
524 if (prev_pid == -1)
525 return;
526/*
527 * Context-switch trace line:
528
529 ------------------------------------------
530 | 1) migration/0--1 => sshd-1755
531 ------------------------------------------
532
533 */
534 trace_seq_puts(s, " ------------------------------------------\n");
535 print_graph_cpu(s, cpu);
536 print_graph_proc(s, prev_pid);
537 trace_seq_puts(s, " => ");
538 print_graph_proc(s, pid);
539 trace_seq_puts(s, "\n ------------------------------------------\n\n");
540}
541
542static struct ftrace_graph_ret_entry *
543get_return_for_leaf(struct trace_iterator *iter,
544 struct ftrace_graph_ent_entry *curr)
545{
546 struct fgraph_data *data = iter->private;
547 struct ring_buffer_iter *ring_iter = NULL;
548 struct ring_buffer_event *event;
549 struct ftrace_graph_ret_entry *next;
550
551 /*
552 * If the previous output failed to write to the seq buffer,
553 * then we just reuse the data from before.
554 */
555 if (data && data->failed) {
556 curr = &data->ent.ent;
557 next = &data->ret;
558 } else {
559
560 ring_iter = trace_buffer_iter(iter, iter->cpu);
561
562 /* First peek to compare current entry and the next one */
563 if (ring_iter)
564 event = ring_buffer_iter_peek(ring_iter, NULL);
565 else {
566 /*
567 * We need to consume the current entry to see
568 * the next one.
569 */
570 ring_buffer_consume(iter->array_buffer->buffer, iter->cpu,
571 NULL, NULL);
572 event = ring_buffer_peek(iter->array_buffer->buffer, iter->cpu,
573 NULL, NULL);
574 }
575
576 if (!event)
577 return NULL;
578
579 next = ring_buffer_event_data(event);
580
581 if (data) {
582 /*
583 * Save current and next entries for later reference
584 * if the output fails.
585 */
586 if (unlikely(curr->ent.type == TRACE_GRAPH_RETADDR_ENT))
587 data->ent.rent = *(struct fgraph_retaddr_ent_entry *)curr;
588 else
589 data->ent.ent = *curr;
590 /*
591 * If the next event is not a return type, then
592 * we only care about what type it is. Otherwise we can
593 * safely copy the entire event.
594 */
595 if (next->ent.type == TRACE_GRAPH_RET)
596 data->ret = *next;
597 else
598 data->ret.ent.type = next->ent.type;
599 }
600 }
601
602 if (next->ent.type != TRACE_GRAPH_RET)
603 return NULL;
604
605 if (curr->ent.pid != next->ent.pid ||
606 curr->graph_ent.func != next->ret.func)
607 return NULL;
608
609 /* this is a leaf, now advance the iterator */
610 if (ring_iter)
611 ring_buffer_iter_advance(ring_iter);
612
613 return next;
614}
615
616static void print_graph_abs_time(u64 t, struct trace_seq *s)
617{
618 unsigned long usecs_rem;
619
620 usecs_rem = do_div(t, NSEC_PER_SEC);
621 usecs_rem /= 1000;
622
623 trace_seq_printf(s, "%5lu.%06lu | ",
624 (unsigned long)t, usecs_rem);
625}
626
627static void
628print_graph_rel_time(struct trace_iterator *iter, struct trace_seq *s)
629{
630 unsigned long long usecs;
631
632 usecs = iter->ts - iter->array_buffer->time_start;
633 do_div(usecs, NSEC_PER_USEC);
634
635 trace_seq_printf(s, "%9llu us | ", usecs);
636}
637
638static void
639print_graph_irq(struct trace_iterator *iter, unsigned long addr,
640 enum trace_type type, int cpu, pid_t pid, u32 flags)
641{
642 struct trace_array *tr = iter->tr;
643 struct trace_seq *s = &iter->seq;
644 struct trace_entry *ent = iter->ent;
645
646 addr += iter->tr->text_delta;
647
648 if (addr < (unsigned long)__irqentry_text_start ||
649 addr >= (unsigned long)__irqentry_text_end)
650 return;
651
652 if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
653 /* Absolute time */
654 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
655 print_graph_abs_time(iter->ts, s);
656
657 /* Relative time */
658 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
659 print_graph_rel_time(iter, s);
660
661 /* Cpu */
662 if (flags & TRACE_GRAPH_PRINT_CPU)
663 print_graph_cpu(s, cpu);
664
665 /* Proc */
666 if (flags & TRACE_GRAPH_PRINT_PROC) {
667 print_graph_proc(s, pid);
668 trace_seq_puts(s, " | ");
669 }
670
671 /* Latency format */
672 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
673 print_graph_lat_fmt(s, ent);
674 }
675
676 /* No overhead */
677 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_START);
678
679 if (type == TRACE_GRAPH_ENT)
680 trace_seq_puts(s, "==========>");
681 else
682 trace_seq_puts(s, "<==========");
683
684 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_END);
685 trace_seq_putc(s, '\n');
686}
687
688void
689trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
690{
691 unsigned long nsecs_rem = do_div(duration, 1000);
692 /* log10(ULONG_MAX) + '\0' */
693 char usecs_str[21];
694 char nsecs_str[5];
695 int len;
696 int i;
697
698 sprintf(usecs_str, "%lu", (unsigned long) duration);
699
700 /* Print msecs */
701 trace_seq_printf(s, "%s", usecs_str);
702
703 len = strlen(usecs_str);
704
705 /* Print nsecs (we don't want to exceed 7 numbers) */
706 if (len < 7) {
707 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
708
709 snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
710 trace_seq_printf(s, ".%s", nsecs_str);
711 len += strlen(nsecs_str) + 1;
712 }
713
714 trace_seq_puts(s, " us ");
715
716 /* Print remaining spaces to fit the row's width */
717 for (i = len; i < 8; i++)
718 trace_seq_putc(s, ' ');
719}
720
721static void
722print_graph_duration(struct trace_array *tr, unsigned long long duration,
723 struct trace_seq *s, u32 flags)
724{
725 if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
726 !(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
727 return;
728
729 /* No real adata, just filling the column with spaces */
730 switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
731 case FLAGS_FILL_FULL:
732 trace_seq_puts(s, " | ");
733 return;
734 case FLAGS_FILL_START:
735 trace_seq_puts(s, " ");
736 return;
737 case FLAGS_FILL_END:
738 trace_seq_puts(s, " |");
739 return;
740 }
741
742 /* Signal a overhead of time execution to the output */
743 if (flags & TRACE_GRAPH_PRINT_OVERHEAD)
744 trace_seq_printf(s, "%c ", trace_find_mark(duration));
745 else
746 trace_seq_puts(s, " ");
747
748 trace_print_graph_duration(duration, s);
749 trace_seq_puts(s, "| ");
750}
751
752#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
753#define __TRACE_GRAPH_PRINT_RETVAL TRACE_GRAPH_PRINT_RETVAL
754#else
755#define __TRACE_GRAPH_PRINT_RETVAL 0
756#endif
757
758#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
759#define __TRACE_GRAPH_PRINT_RETADDR TRACE_GRAPH_PRINT_RETADDR
760static void print_graph_retaddr(struct trace_seq *s, struct fgraph_retaddr_ent_entry *entry,
761 u32 trace_flags, bool comment)
762{
763 if (comment)
764 trace_seq_puts(s, " /*");
765
766 trace_seq_puts(s, " <-");
767 seq_print_ip_sym(s, entry->graph_ent.retaddr, trace_flags | TRACE_ITER_SYM_OFFSET);
768
769 if (comment)
770 trace_seq_puts(s, " */");
771}
772#else
773#define __TRACE_GRAPH_PRINT_RETADDR 0
774#define print_graph_retaddr(_seq, _entry, _tflags, _comment) do { } while (0)
775#endif
776
777#if defined(CONFIG_FUNCTION_GRAPH_RETVAL) || defined(CONFIG_FUNCTION_GRAPH_RETADDR)
778
779static void print_graph_retval(struct trace_seq *s, struct ftrace_graph_ent_entry *entry,
780 struct ftrace_graph_ret *graph_ret, void *func,
781 u32 opt_flags, u32 trace_flags)
782{
783 unsigned long err_code = 0;
784 unsigned long retval = 0;
785 bool print_retaddr = false;
786 bool print_retval = false;
787 bool hex_format = !!(opt_flags & TRACE_GRAPH_PRINT_RETVAL_HEX);
788
789#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
790 retval = graph_ret->retval;
791 print_retval = !!(opt_flags & TRACE_GRAPH_PRINT_RETVAL);
792#endif
793
794#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
795 print_retaddr = !!(opt_flags & TRACE_GRAPH_PRINT_RETADDR);
796#endif
797
798 if (print_retval && retval && !hex_format) {
799 /* Check if the return value matches the negative format */
800 if (IS_ENABLED(CONFIG_64BIT) && (retval & BIT(31)) &&
801 (((u64)retval) >> 32) == 0) {
802 err_code = sign_extend64(retval, 31);
803 } else {
804 err_code = retval;
805 }
806
807 if (!IS_ERR_VALUE(err_code))
808 err_code = 0;
809 }
810
811 if (entry) {
812 if (entry->ent.type != TRACE_GRAPH_RETADDR_ENT)
813 print_retaddr = false;
814
815 trace_seq_printf(s, "%ps();", func);
816 if (print_retval || print_retaddr)
817 trace_seq_puts(s, " /*");
818 else
819 trace_seq_putc(s, '\n');
820 } else {
821 print_retaddr = false;
822 trace_seq_printf(s, "} /* %ps", func);
823 }
824
825 if (print_retaddr)
826 print_graph_retaddr(s, (struct fgraph_retaddr_ent_entry *)entry,
827 trace_flags, false);
828
829 if (print_retval) {
830 if (hex_format || (err_code == 0))
831 trace_seq_printf(s, " ret=0x%lx", retval);
832 else
833 trace_seq_printf(s, " ret=%ld", err_code);
834 }
835
836 if (!entry || print_retval || print_retaddr)
837 trace_seq_puts(s, " */\n");
838}
839
840#else
841
842#define print_graph_retval(_seq, _ent, _ret, _func, _opt_flags, _trace_flags) do {} while (0)
843
844#endif
845
846/* Case of a leaf function on its call entry */
847static enum print_line_t
848print_graph_entry_leaf(struct trace_iterator *iter,
849 struct ftrace_graph_ent_entry *entry,
850 struct ftrace_graph_ret_entry *ret_entry,
851 struct trace_seq *s, u32 flags)
852{
853 struct fgraph_data *data = iter->private;
854 struct trace_array *tr = iter->tr;
855 struct ftrace_graph_ret *graph_ret;
856 struct ftrace_graph_ent *call;
857 unsigned long long duration;
858 unsigned long func;
859 int cpu = iter->cpu;
860 int i;
861
862 graph_ret = &ret_entry->ret;
863 call = &entry->graph_ent;
864 duration = graph_ret->rettime - graph_ret->calltime;
865
866 func = call->func + iter->tr->text_delta;
867
868 if (data) {
869 struct fgraph_cpu_data *cpu_data;
870
871 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
872
873 /*
874 * Comments display at + 1 to depth. Since
875 * this is a leaf function, keep the comments
876 * equal to this depth.
877 */
878 cpu_data->depth = call->depth - 1;
879
880 /* No need to keep this function around for this depth */
881 if (call->depth < FTRACE_RETFUNC_DEPTH &&
882 !WARN_ON_ONCE(call->depth < 0))
883 cpu_data->enter_funcs[call->depth] = 0;
884 }
885
886 /* Overhead and duration */
887 print_graph_duration(tr, duration, s, flags);
888
889 /* Function */
890 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
891 trace_seq_putc(s, ' ');
892
893 /*
894 * Write out the function return value or return address
895 */
896 if (flags & (__TRACE_GRAPH_PRINT_RETVAL | __TRACE_GRAPH_PRINT_RETADDR)) {
897 print_graph_retval(s, entry, graph_ret,
898 (void *)graph_ret->func + iter->tr->text_delta,
899 flags, tr->trace_flags);
900 } else {
901 trace_seq_printf(s, "%ps();\n", (void *)func);
902 }
903
904 print_graph_irq(iter, graph_ret->func, TRACE_GRAPH_RET,
905 cpu, iter->ent->pid, flags);
906
907 return trace_handle_return(s);
908}
909
910static enum print_line_t
911print_graph_entry_nested(struct trace_iterator *iter,
912 struct ftrace_graph_ent_entry *entry,
913 struct trace_seq *s, int cpu, u32 flags)
914{
915 struct ftrace_graph_ent *call = &entry->graph_ent;
916 struct fgraph_data *data = iter->private;
917 struct trace_array *tr = iter->tr;
918 unsigned long func;
919 int i;
920
921 if (data) {
922 struct fgraph_cpu_data *cpu_data;
923 int cpu = iter->cpu;
924
925 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
926 cpu_data->depth = call->depth;
927
928 /* Save this function pointer to see if the exit matches */
929 if (call->depth < FTRACE_RETFUNC_DEPTH &&
930 !WARN_ON_ONCE(call->depth < 0))
931 cpu_data->enter_funcs[call->depth] = call->func;
932 }
933
934 /* No time */
935 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
936
937 /* Function */
938 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
939 trace_seq_putc(s, ' ');
940
941 func = call->func + iter->tr->text_delta;
942
943 trace_seq_printf(s, "%ps() {", (void *)func);
944 if (flags & __TRACE_GRAPH_PRINT_RETADDR &&
945 entry->ent.type == TRACE_GRAPH_RETADDR_ENT)
946 print_graph_retaddr(s, (struct fgraph_retaddr_ent_entry *)entry,
947 tr->trace_flags, true);
948 trace_seq_putc(s, '\n');
949
950 if (trace_seq_has_overflowed(s))
951 return TRACE_TYPE_PARTIAL_LINE;
952
953 /*
954 * we already consumed the current entry to check the next one
955 * and see if this is a leaf.
956 */
957 return TRACE_TYPE_NO_CONSUME;
958}
959
960static void
961print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
962 int type, unsigned long addr, u32 flags)
963{
964 struct fgraph_data *data = iter->private;
965 struct trace_entry *ent = iter->ent;
966 struct trace_array *tr = iter->tr;
967 int cpu = iter->cpu;
968
969 /* Pid */
970 verif_pid(s, ent->pid, cpu, data);
971
972 if (type)
973 /* Interrupt */
974 print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
975
976 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
977 return;
978
979 /* Absolute time */
980 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
981 print_graph_abs_time(iter->ts, s);
982
983 /* Relative time */
984 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
985 print_graph_rel_time(iter, s);
986
987 /* Cpu */
988 if (flags & TRACE_GRAPH_PRINT_CPU)
989 print_graph_cpu(s, cpu);
990
991 /* Proc */
992 if (flags & TRACE_GRAPH_PRINT_PROC) {
993 print_graph_proc(s, ent->pid);
994 trace_seq_puts(s, " | ");
995 }
996
997 /* Latency format */
998 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
999 print_graph_lat_fmt(s, ent);
1000
1001 return;
1002}
1003
1004/*
1005 * Entry check for irq code
1006 *
1007 * returns 1 if
1008 * - we are inside irq code
1009 * - we just entered irq code
1010 *
1011 * returns 0 if
1012 * - funcgraph-interrupts option is set
1013 * - we are not inside irq code
1014 */
1015static int
1016check_irq_entry(struct trace_iterator *iter, u32 flags,
1017 unsigned long addr, int depth)
1018{
1019 int cpu = iter->cpu;
1020 int *depth_irq;
1021 struct fgraph_data *data = iter->private;
1022
1023 addr += iter->tr->text_delta;
1024
1025 /*
1026 * If we are either displaying irqs, or we got called as
1027 * a graph event and private data does not exist,
1028 * then we bypass the irq check.
1029 */
1030 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
1031 (!data))
1032 return 0;
1033
1034 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1035
1036 /*
1037 * We are inside the irq code
1038 */
1039 if (*depth_irq >= 0)
1040 return 1;
1041
1042 if ((addr < (unsigned long)__irqentry_text_start) ||
1043 (addr >= (unsigned long)__irqentry_text_end))
1044 return 0;
1045
1046 /*
1047 * We are entering irq code.
1048 */
1049 *depth_irq = depth;
1050 return 1;
1051}
1052
1053/*
1054 * Return check for irq code
1055 *
1056 * returns 1 if
1057 * - we are inside irq code
1058 * - we just left irq code
1059 *
1060 * returns 0 if
1061 * - funcgraph-interrupts option is set
1062 * - we are not inside irq code
1063 */
1064static int
1065check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
1066{
1067 int cpu = iter->cpu;
1068 int *depth_irq;
1069 struct fgraph_data *data = iter->private;
1070
1071 /*
1072 * If we are either displaying irqs, or we got called as
1073 * a graph event and private data does not exist,
1074 * then we bypass the irq check.
1075 */
1076 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
1077 (!data))
1078 return 0;
1079
1080 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1081
1082 /*
1083 * We are not inside the irq code.
1084 */
1085 if (*depth_irq == -1)
1086 return 0;
1087
1088 /*
1089 * We are inside the irq code, and this is returning entry.
1090 * Let's not trace it and clear the entry depth, since
1091 * we are out of irq code.
1092 *
1093 * This condition ensures that we 'leave the irq code' once
1094 * we are out of the entry depth. Thus protecting us from
1095 * the RETURN entry loss.
1096 */
1097 if (*depth_irq >= depth) {
1098 *depth_irq = -1;
1099 return 1;
1100 }
1101
1102 /*
1103 * We are inside the irq code, and this is not the entry.
1104 */
1105 return 1;
1106}
1107
1108static enum print_line_t
1109print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
1110 struct trace_iterator *iter, u32 flags)
1111{
1112 struct fgraph_data *data = iter->private;
1113 struct ftrace_graph_ent *call = &field->graph_ent;
1114 struct ftrace_graph_ret_entry *leaf_ret;
1115 static enum print_line_t ret;
1116 int cpu = iter->cpu;
1117
1118 if (check_irq_entry(iter, flags, call->func, call->depth))
1119 return TRACE_TYPE_HANDLED;
1120
1121 print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags);
1122
1123 leaf_ret = get_return_for_leaf(iter, field);
1124 if (leaf_ret)
1125 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
1126 else
1127 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
1128
1129 if (data) {
1130 /*
1131 * If we failed to write our output, then we need to make
1132 * note of it. Because we already consumed our entry.
1133 */
1134 if (s->full) {
1135 data->failed = 1;
1136 data->cpu = cpu;
1137 } else
1138 data->failed = 0;
1139 }
1140
1141 return ret;
1142}
1143
1144static enum print_line_t
1145print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
1146 struct trace_entry *ent, struct trace_iterator *iter,
1147 u32 flags)
1148{
1149 unsigned long long duration = trace->rettime - trace->calltime;
1150 struct fgraph_data *data = iter->private;
1151 struct trace_array *tr = iter->tr;
1152 unsigned long func;
1153 pid_t pid = ent->pid;
1154 int cpu = iter->cpu;
1155 int func_match = 1;
1156 int i;
1157
1158 func = trace->func + iter->tr->text_delta;
1159
1160 if (check_irq_return(iter, flags, trace->depth))
1161 return TRACE_TYPE_HANDLED;
1162
1163 if (data) {
1164 struct fgraph_cpu_data *cpu_data;
1165 int cpu = iter->cpu;
1166
1167 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1168
1169 /*
1170 * Comments display at + 1 to depth. This is the
1171 * return from a function, we now want the comments
1172 * to display at the same level of the bracket.
1173 */
1174 cpu_data->depth = trace->depth - 1;
1175
1176 if (trace->depth < FTRACE_RETFUNC_DEPTH &&
1177 !WARN_ON_ONCE(trace->depth < 0)) {
1178 if (cpu_data->enter_funcs[trace->depth] != trace->func)
1179 func_match = 0;
1180 cpu_data->enter_funcs[trace->depth] = 0;
1181 }
1182 }
1183
1184 print_graph_prologue(iter, s, 0, 0, flags);
1185
1186 /* Overhead and duration */
1187 print_graph_duration(tr, duration, s, flags);
1188
1189 /* Closing brace */
1190 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++)
1191 trace_seq_putc(s, ' ');
1192
1193 /*
1194 * Always write out the function name and its return value if the
1195 * funcgraph-retval option is enabled.
1196 */
1197 if (flags & __TRACE_GRAPH_PRINT_RETVAL) {
1198 print_graph_retval(s, NULL, trace, (void *)func, flags, tr->trace_flags);
1199 } else {
1200 /*
1201 * If the return function does not have a matching entry,
1202 * then the entry was lost. Instead of just printing
1203 * the '}' and letting the user guess what function this
1204 * belongs to, write out the function name. Always do
1205 * that if the funcgraph-tail option is enabled.
1206 */
1207 if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL))
1208 trace_seq_puts(s, "}\n");
1209 else
1210 trace_seq_printf(s, "} /* %ps */\n", (void *)func);
1211 }
1212
1213 /* Overrun */
1214 if (flags & TRACE_GRAPH_PRINT_OVERRUN)
1215 trace_seq_printf(s, " (Overruns: %u)\n",
1216 trace->overrun);
1217
1218 print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
1219 cpu, pid, flags);
1220
1221 return trace_handle_return(s);
1222}
1223
1224static enum print_line_t
1225print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
1226 struct trace_iterator *iter, u32 flags)
1227{
1228 struct trace_array *tr = iter->tr;
1229 unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
1230 struct fgraph_data *data = iter->private;
1231 struct trace_event *event;
1232 int depth = 0;
1233 int ret;
1234 int i;
1235
1236 if (data)
1237 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
1238
1239 print_graph_prologue(iter, s, 0, 0, flags);
1240
1241 /* No time */
1242 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
1243
1244 /* Indentation */
1245 if (depth > 0)
1246 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++)
1247 trace_seq_putc(s, ' ');
1248
1249 /* The comment */
1250 trace_seq_puts(s, "/* ");
1251
1252 switch (iter->ent->type) {
1253 case TRACE_BPUTS:
1254 ret = trace_print_bputs_msg_only(iter);
1255 if (ret != TRACE_TYPE_HANDLED)
1256 return ret;
1257 break;
1258 case TRACE_BPRINT:
1259 ret = trace_print_bprintk_msg_only(iter);
1260 if (ret != TRACE_TYPE_HANDLED)
1261 return ret;
1262 break;
1263 case TRACE_PRINT:
1264 ret = trace_print_printk_msg_only(iter);
1265 if (ret != TRACE_TYPE_HANDLED)
1266 return ret;
1267 break;
1268 default:
1269 event = ftrace_find_event(ent->type);
1270 if (!event)
1271 return TRACE_TYPE_UNHANDLED;
1272
1273 ret = event->funcs->trace(iter, sym_flags, event);
1274 if (ret != TRACE_TYPE_HANDLED)
1275 return ret;
1276 }
1277
1278 if (trace_seq_has_overflowed(s))
1279 goto out;
1280
1281 /* Strip ending newline */
1282 if (s->buffer[s->seq.len - 1] == '\n') {
1283 s->buffer[s->seq.len - 1] = '\0';
1284 s->seq.len--;
1285 }
1286
1287 trace_seq_puts(s, " */\n");
1288 out:
1289 return trace_handle_return(s);
1290}
1291
1292
1293enum print_line_t
1294print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1295{
1296 struct ftrace_graph_ent_entry *field;
1297 struct fgraph_data *data = iter->private;
1298 struct trace_entry *entry = iter->ent;
1299 struct trace_seq *s = &iter->seq;
1300 int cpu = iter->cpu;
1301 int ret;
1302
1303 if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1304 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1305 return TRACE_TYPE_HANDLED;
1306 }
1307
1308 /*
1309 * If the last output failed, there's a possibility we need
1310 * to print out the missing entry which would never go out.
1311 */
1312 if (data && data->failed) {
1313 field = &data->ent.ent;
1314 iter->cpu = data->cpu;
1315 ret = print_graph_entry(field, s, iter, flags);
1316 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1317 per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1318 ret = TRACE_TYPE_NO_CONSUME;
1319 }
1320 iter->cpu = cpu;
1321 return ret;
1322 }
1323
1324 switch (entry->type) {
1325 case TRACE_GRAPH_ENT: {
1326 /*
1327 * print_graph_entry() may consume the current event,
1328 * thus @field may become invalid, so we need to save it.
1329 * sizeof(struct ftrace_graph_ent_entry) is very small,
1330 * it can be safely saved at the stack.
1331 */
1332 struct ftrace_graph_ent_entry saved;
1333 trace_assign_type(field, entry);
1334 saved = *field;
1335 return print_graph_entry(&saved, s, iter, flags);
1336 }
1337#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
1338 case TRACE_GRAPH_RETADDR_ENT: {
1339 struct fgraph_retaddr_ent_entry saved;
1340 struct fgraph_retaddr_ent_entry *rfield;
1341
1342 trace_assign_type(rfield, entry);
1343 saved = *rfield;
1344 return print_graph_entry((struct ftrace_graph_ent_entry *)&saved, s, iter, flags);
1345 }
1346#endif
1347 case TRACE_GRAPH_RET: {
1348 struct ftrace_graph_ret_entry *field;
1349 trace_assign_type(field, entry);
1350 return print_graph_return(&field->ret, s, entry, iter, flags);
1351 }
1352 case TRACE_STACK:
1353 case TRACE_FN:
1354 /* dont trace stack and functions as comments */
1355 return TRACE_TYPE_UNHANDLED;
1356
1357 default:
1358 return print_graph_comment(s, entry, iter, flags);
1359 }
1360
1361 return TRACE_TYPE_HANDLED;
1362}
1363
1364static enum print_line_t
1365print_graph_function(struct trace_iterator *iter)
1366{
1367 return print_graph_function_flags(iter, tracer_flags.val);
1368}
1369
1370static enum print_line_t
1371print_graph_function_event(struct trace_iterator *iter, int flags,
1372 struct trace_event *event)
1373{
1374 return print_graph_function(iter);
1375}
1376
1377static void print_lat_header(struct seq_file *s, u32 flags)
1378{
1379 static const char spaces[] = " " /* 16 spaces */
1380 " " /* 4 spaces */
1381 " "; /* 17 spaces */
1382 int size = 0;
1383
1384 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1385 size += 16;
1386 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1387 size += 16;
1388 if (flags & TRACE_GRAPH_PRINT_CPU)
1389 size += 4;
1390 if (flags & TRACE_GRAPH_PRINT_PROC)
1391 size += 17;
1392
1393 seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces);
1394 seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
1395 seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1396 seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
1397 seq_printf(s, "#%.*s||| / \n", size, spaces);
1398}
1399
1400static void __print_graph_headers_flags(struct trace_array *tr,
1401 struct seq_file *s, u32 flags)
1402{
1403 int lat = tr->trace_flags & TRACE_ITER_LATENCY_FMT;
1404
1405 if (lat)
1406 print_lat_header(s, flags);
1407
1408 /* 1st line */
1409 seq_putc(s, '#');
1410 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1411 seq_puts(s, " TIME ");
1412 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1413 seq_puts(s, " REL TIME ");
1414 if (flags & TRACE_GRAPH_PRINT_CPU)
1415 seq_puts(s, " CPU");
1416 if (flags & TRACE_GRAPH_PRINT_PROC)
1417 seq_puts(s, " TASK/PID ");
1418 if (lat)
1419 seq_puts(s, "|||| ");
1420 if (flags & TRACE_GRAPH_PRINT_DURATION)
1421 seq_puts(s, " DURATION ");
1422 seq_puts(s, " FUNCTION CALLS\n");
1423
1424 /* 2nd line */
1425 seq_putc(s, '#');
1426 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1427 seq_puts(s, " | ");
1428 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1429 seq_puts(s, " | ");
1430 if (flags & TRACE_GRAPH_PRINT_CPU)
1431 seq_puts(s, " | ");
1432 if (flags & TRACE_GRAPH_PRINT_PROC)
1433 seq_puts(s, " | | ");
1434 if (lat)
1435 seq_puts(s, "|||| ");
1436 if (flags & TRACE_GRAPH_PRINT_DURATION)
1437 seq_puts(s, " | | ");
1438 seq_puts(s, " | | | |\n");
1439}
1440
1441static void print_graph_headers(struct seq_file *s)
1442{
1443 print_graph_headers_flags(s, tracer_flags.val);
1444}
1445
1446void print_graph_headers_flags(struct seq_file *s, u32 flags)
1447{
1448 struct trace_iterator *iter = s->private;
1449 struct trace_array *tr = iter->tr;
1450
1451 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
1452 return;
1453
1454 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) {
1455 /* print nothing if the buffers are empty */
1456 if (trace_empty(iter))
1457 return;
1458
1459 print_trace_header(s, iter);
1460 }
1461
1462 __print_graph_headers_flags(tr, s, flags);
1463}
1464
1465void graph_trace_open(struct trace_iterator *iter)
1466{
1467 /* pid and depth on the last trace processed */
1468 struct fgraph_data *data;
1469 gfp_t gfpflags;
1470 int cpu;
1471
1472 iter->private = NULL;
1473
1474 /* We can be called in atomic context via ftrace_dump() */
1475 gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL;
1476
1477 data = kzalloc(sizeof(*data), gfpflags);
1478 if (!data)
1479 goto out_err;
1480
1481 data->cpu_data = alloc_percpu_gfp(struct fgraph_cpu_data, gfpflags);
1482 if (!data->cpu_data)
1483 goto out_err_free;
1484
1485 for_each_possible_cpu(cpu) {
1486 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1487 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1488 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1489 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1490
1491 *pid = -1;
1492 *depth = 0;
1493 *ignore = 0;
1494 *depth_irq = -1;
1495 }
1496
1497 iter->private = data;
1498
1499 return;
1500
1501 out_err_free:
1502 kfree(data);
1503 out_err:
1504 pr_warn("function graph tracer: not enough memory\n");
1505}
1506
1507void graph_trace_close(struct trace_iterator *iter)
1508{
1509 struct fgraph_data *data = iter->private;
1510
1511 if (data) {
1512 free_percpu(data->cpu_data);
1513 kfree(data);
1514 }
1515}
1516
1517static int
1518func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
1519{
1520 if (bit == TRACE_GRAPH_PRINT_IRQS)
1521 ftrace_graph_skip_irqs = !set;
1522
1523 if (bit == TRACE_GRAPH_SLEEP_TIME)
1524 ftrace_graph_sleep_time_control(set);
1525
1526 if (bit == TRACE_GRAPH_GRAPH_TIME)
1527 ftrace_graph_graph_time_control(set);
1528
1529 return 0;
1530}
1531
1532static struct trace_event_functions graph_functions = {
1533 .trace = print_graph_function_event,
1534};
1535
1536static struct trace_event graph_trace_entry_event = {
1537 .type = TRACE_GRAPH_ENT,
1538 .funcs = &graph_functions,
1539};
1540
1541#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
1542static struct trace_event graph_trace_retaddr_entry_event = {
1543 .type = TRACE_GRAPH_RETADDR_ENT,
1544 .funcs = &graph_functions,
1545};
1546#endif
1547
1548static struct trace_event graph_trace_ret_event = {
1549 .type = TRACE_GRAPH_RET,
1550 .funcs = &graph_functions
1551};
1552
1553static struct tracer graph_trace __tracer_data = {
1554 .name = "function_graph",
1555 .update_thresh = graph_trace_update_thresh,
1556 .open = graph_trace_open,
1557 .pipe_open = graph_trace_open,
1558 .close = graph_trace_close,
1559 .pipe_close = graph_trace_close,
1560 .init = graph_trace_init,
1561 .reset = graph_trace_reset,
1562 .print_line = print_graph_function,
1563 .print_header = print_graph_headers,
1564 .flags = &tracer_flags,
1565 .set_flag = func_graph_set_flag,
1566 .allow_instances = true,
1567#ifdef CONFIG_FTRACE_SELFTEST
1568 .selftest = trace_selftest_startup_function_graph,
1569#endif
1570};
1571
1572
1573static ssize_t
1574graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
1575 loff_t *ppos)
1576{
1577 unsigned long val;
1578 int ret;
1579
1580 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1581 if (ret)
1582 return ret;
1583
1584 fgraph_max_depth = val;
1585
1586 *ppos += cnt;
1587
1588 return cnt;
1589}
1590
1591static ssize_t
1592graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
1593 loff_t *ppos)
1594{
1595 char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/
1596 int n;
1597
1598 n = sprintf(buf, "%d\n", fgraph_max_depth);
1599
1600 return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
1601}
1602
1603static const struct file_operations graph_depth_fops = {
1604 .open = tracing_open_generic,
1605 .write = graph_depth_write,
1606 .read = graph_depth_read,
1607 .llseek = generic_file_llseek,
1608};
1609
1610static __init int init_graph_tracefs(void)
1611{
1612 int ret;
1613
1614 ret = tracing_init_dentry();
1615 if (ret)
1616 return 0;
1617
1618 trace_create_file("max_graph_depth", TRACE_MODE_WRITE, NULL,
1619 NULL, &graph_depth_fops);
1620
1621 return 0;
1622}
1623fs_initcall(init_graph_tracefs);
1624
1625static __init int init_graph_trace(void)
1626{
1627 max_bytes_for_cpu = snprintf(NULL, 0, "%u", nr_cpu_ids - 1);
1628
1629 if (!register_trace_event(&graph_trace_entry_event)) {
1630 pr_warn("Warning: could not register graph trace events\n");
1631 return 1;
1632 }
1633
1634#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
1635 if (!register_trace_event(&graph_trace_retaddr_entry_event)) {
1636 pr_warn("Warning: could not register graph trace retaddr events\n");
1637 return 1;
1638 }
1639#endif
1640
1641 if (!register_trace_event(&graph_trace_ret_event)) {
1642 pr_warn("Warning: could not register graph trace events\n");
1643 return 1;
1644 }
1645
1646 return register_tracer(&graph_trace);
1647}
1648
1649core_initcall(init_graph_trace);