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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 long flags,
100 int pc)
101{
102 struct trace_event_call *call = &event_funcgraph_entry;
103 struct ring_buffer_event *event;
104 struct ring_buffer *buffer = tr->trace_buffer.buffer;
105 struct ftrace_graph_ent_entry *entry;
106
107 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
108 sizeof(*entry), flags, pc);
109 if (!event)
110 return 0;
111 entry = ring_buffer_event_data(event);
112 entry->graph_ent = *trace;
113 if (!call_filter_check_discard(call, entry, buffer, event))
114 trace_buffer_unlock_commit_nostack(buffer, event);
115
116 return 1;
117}
118
119static inline int ftrace_graph_ignore_irqs(void)
120{
121 if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
122 return 0;
123
124 return in_irq();
125}
126
127int trace_graph_entry(struct ftrace_graph_ent *trace)
128{
129 struct trace_array *tr = graph_array;
130 struct trace_array_cpu *data;
131 unsigned long flags;
132 long disabled;
133 int ret;
134 int cpu;
135 int pc;
136
137 if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT))
138 return 0;
139
140 /*
141 * Do not trace a function if it's filtered by set_graph_notrace.
142 * Make the index of ret stack negative to indicate that it should
143 * ignore further functions. But it needs its own ret stack entry
144 * to recover the original index in order to continue tracing after
145 * returning from the function.
146 */
147 if (ftrace_graph_notrace_addr(trace->func)) {
148 trace_recursion_set(TRACE_GRAPH_NOTRACE_BIT);
149 /*
150 * Need to return 1 to have the return called
151 * that will clear the NOTRACE bit.
152 */
153 return 1;
154 }
155
156 if (!ftrace_trace_task(tr))
157 return 0;
158
159 if (ftrace_graph_ignore_func(trace))
160 return 0;
161
162 if (ftrace_graph_ignore_irqs())
163 return 0;
164
165 /*
166 * Stop here if tracing_threshold is set. We only write function return
167 * events to the ring buffer.
168 */
169 if (tracing_thresh)
170 return 1;
171
172 local_irq_save(flags);
173 cpu = raw_smp_processor_id();
174 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
175 disabled = atomic_inc_return(&data->disabled);
176 if (likely(disabled == 1)) {
177 pc = preempt_count();
178 ret = __trace_graph_entry(tr, trace, flags, pc);
179 } else {
180 ret = 0;
181 }
182
183 atomic_dec(&data->disabled);
184 local_irq_restore(flags);
185
186 return ret;
187}
188
189static void
190__trace_graph_function(struct trace_array *tr,
191 unsigned long ip, unsigned long flags, int pc)
192{
193 u64 time = trace_clock_local();
194 struct ftrace_graph_ent ent = {
195 .func = ip,
196 .depth = 0,
197 };
198 struct ftrace_graph_ret ret = {
199 .func = ip,
200 .depth = 0,
201 .calltime = time,
202 .rettime = time,
203 };
204
205 __trace_graph_entry(tr, &ent, flags, pc);
206 __trace_graph_return(tr, &ret, flags, pc);
207}
208
209void
210trace_graph_function(struct trace_array *tr,
211 unsigned long ip, unsigned long parent_ip,
212 unsigned long flags, int pc)
213{
214 __trace_graph_function(tr, ip, flags, pc);
215}
216
217void __trace_graph_return(struct trace_array *tr,
218 struct ftrace_graph_ret *trace,
219 unsigned long flags,
220 int pc)
221{
222 struct trace_event_call *call = &event_funcgraph_exit;
223 struct ring_buffer_event *event;
224 struct ring_buffer *buffer = tr->trace_buffer.buffer;
225 struct ftrace_graph_ret_entry *entry;
226
227 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
228 sizeof(*entry), flags, pc);
229 if (!event)
230 return;
231 entry = ring_buffer_event_data(event);
232 entry->ret = *trace;
233 if (!call_filter_check_discard(call, entry, buffer, event))
234 trace_buffer_unlock_commit_nostack(buffer, event);
235}
236
237void trace_graph_return(struct ftrace_graph_ret *trace)
238{
239 struct trace_array *tr = graph_array;
240 struct trace_array_cpu *data;
241 unsigned long flags;
242 long disabled;
243 int cpu;
244 int pc;
245
246 ftrace_graph_addr_finish(trace);
247
248 if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
249 trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
250 return;
251 }
252
253 local_irq_save(flags);
254 cpu = raw_smp_processor_id();
255 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
256 disabled = atomic_inc_return(&data->disabled);
257 if (likely(disabled == 1)) {
258 pc = preempt_count();
259 __trace_graph_return(tr, trace, flags, pc);
260 }
261 atomic_dec(&data->disabled);
262 local_irq_restore(flags);
263}
264
265void set_graph_array(struct trace_array *tr)
266{
267 graph_array = tr;
268
269 /* Make graph_array visible before we start tracing */
270
271 smp_mb();
272}
273
274static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
275{
276 ftrace_graph_addr_finish(trace);
277
278 if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
279 trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
280 return;
281 }
282
283 if (tracing_thresh &&
284 (trace->rettime - trace->calltime < tracing_thresh))
285 return;
286 else
287 trace_graph_return(trace);
288}
289
290static struct fgraph_ops funcgraph_thresh_ops = {
291 .entryfunc = &trace_graph_entry,
292 .retfunc = &trace_graph_thresh_return,
293};
294
295static struct fgraph_ops funcgraph_ops = {
296 .entryfunc = &trace_graph_entry,
297 .retfunc = &trace_graph_return,
298};
299
300static int graph_trace_init(struct trace_array *tr)
301{
302 int ret;
303
304 set_graph_array(tr);
305 if (tracing_thresh)
306 ret = register_ftrace_graph(&funcgraph_thresh_ops);
307 else
308 ret = register_ftrace_graph(&funcgraph_ops);
309 if (ret)
310 return ret;
311 tracing_start_cmdline_record();
312
313 return 0;
314}
315
316static void graph_trace_reset(struct trace_array *tr)
317{
318 tracing_stop_cmdline_record();
319 if (tracing_thresh)
320 unregister_ftrace_graph(&funcgraph_thresh_ops);
321 else
322 unregister_ftrace_graph(&funcgraph_ops);
323}
324
325static int graph_trace_update_thresh(struct trace_array *tr)
326{
327 graph_trace_reset(tr);
328 return graph_trace_init(tr);
329}
330
331static int max_bytes_for_cpu;
332
333static void print_graph_cpu(struct trace_seq *s, int cpu)
334{
335 /*
336 * Start with a space character - to make it stand out
337 * to the right a bit when trace output is pasted into
338 * email:
339 */
340 trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
341}
342
343#define TRACE_GRAPH_PROCINFO_LENGTH 14
344
345static void print_graph_proc(struct trace_seq *s, pid_t pid)
346{
347 char comm[TASK_COMM_LEN];
348 /* sign + log10(MAX_INT) + '\0' */
349 char pid_str[11];
350 int spaces = 0;
351 int len;
352 int i;
353
354 trace_find_cmdline(pid, comm);
355 comm[7] = '\0';
356 sprintf(pid_str, "%d", pid);
357
358 /* 1 stands for the "-" character */
359 len = strlen(comm) + strlen(pid_str) + 1;
360
361 if (len < TRACE_GRAPH_PROCINFO_LENGTH)
362 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
363
364 /* First spaces to align center */
365 for (i = 0; i < spaces / 2; i++)
366 trace_seq_putc(s, ' ');
367
368 trace_seq_printf(s, "%s-%s", comm, pid_str);
369
370 /* Last spaces to align center */
371 for (i = 0; i < spaces - (spaces / 2); i++)
372 trace_seq_putc(s, ' ');
373}
374
375
376static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
377{
378 trace_seq_putc(s, ' ');
379 trace_print_lat_fmt(s, entry);
380 trace_seq_puts(s, " | ");
381}
382
383/* If the pid changed since the last trace, output this event */
384static void
385verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
386{
387 pid_t prev_pid;
388 pid_t *last_pid;
389
390 if (!data)
391 return;
392
393 last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
394
395 if (*last_pid == pid)
396 return;
397
398 prev_pid = *last_pid;
399 *last_pid = pid;
400
401 if (prev_pid == -1)
402 return;
403/*
404 * Context-switch trace line:
405
406 ------------------------------------------
407 | 1) migration/0--1 => sshd-1755
408 ------------------------------------------
409
410 */
411 trace_seq_puts(s, " ------------------------------------------\n");
412 print_graph_cpu(s, cpu);
413 print_graph_proc(s, prev_pid);
414 trace_seq_puts(s, " => ");
415 print_graph_proc(s, pid);
416 trace_seq_puts(s, "\n ------------------------------------------\n\n");
417}
418
419static struct ftrace_graph_ret_entry *
420get_return_for_leaf(struct trace_iterator *iter,
421 struct ftrace_graph_ent_entry *curr)
422{
423 struct fgraph_data *data = iter->private;
424 struct ring_buffer_iter *ring_iter = NULL;
425 struct ring_buffer_event *event;
426 struct ftrace_graph_ret_entry *next;
427
428 /*
429 * If the previous output failed to write to the seq buffer,
430 * then we just reuse the data from before.
431 */
432 if (data && data->failed) {
433 curr = &data->ent;
434 next = &data->ret;
435 } else {
436
437 ring_iter = trace_buffer_iter(iter, iter->cpu);
438
439 /* First peek to compare current entry and the next one */
440 if (ring_iter)
441 event = ring_buffer_iter_peek(ring_iter, NULL);
442 else {
443 /*
444 * We need to consume the current entry to see
445 * the next one.
446 */
447 ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu,
448 NULL, NULL);
449 event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu,
450 NULL, NULL);
451 }
452
453 if (!event)
454 return NULL;
455
456 next = ring_buffer_event_data(event);
457
458 if (data) {
459 /*
460 * Save current and next entries for later reference
461 * if the output fails.
462 */
463 data->ent = *curr;
464 /*
465 * If the next event is not a return type, then
466 * we only care about what type it is. Otherwise we can
467 * safely copy the entire event.
468 */
469 if (next->ent.type == TRACE_GRAPH_RET)
470 data->ret = *next;
471 else
472 data->ret.ent.type = next->ent.type;
473 }
474 }
475
476 if (next->ent.type != TRACE_GRAPH_RET)
477 return NULL;
478
479 if (curr->ent.pid != next->ent.pid ||
480 curr->graph_ent.func != next->ret.func)
481 return NULL;
482
483 /* this is a leaf, now advance the iterator */
484 if (ring_iter)
485 ring_buffer_read(ring_iter, NULL);
486
487 return next;
488}
489
490static void print_graph_abs_time(u64 t, struct trace_seq *s)
491{
492 unsigned long usecs_rem;
493
494 usecs_rem = do_div(t, NSEC_PER_SEC);
495 usecs_rem /= 1000;
496
497 trace_seq_printf(s, "%5lu.%06lu | ",
498 (unsigned long)t, usecs_rem);
499}
500
501static void
502print_graph_rel_time(struct trace_iterator *iter, struct trace_seq *s)
503{
504 unsigned long long usecs;
505
506 usecs = iter->ts - iter->trace_buffer->time_start;
507 do_div(usecs, NSEC_PER_USEC);
508
509 trace_seq_printf(s, "%9llu us | ", usecs);
510}
511
512static void
513print_graph_irq(struct trace_iterator *iter, unsigned long addr,
514 enum trace_type type, int cpu, pid_t pid, u32 flags)
515{
516 struct trace_array *tr = iter->tr;
517 struct trace_seq *s = &iter->seq;
518 struct trace_entry *ent = iter->ent;
519
520 if (addr < (unsigned long)__irqentry_text_start ||
521 addr >= (unsigned long)__irqentry_text_end)
522 return;
523
524 if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
525 /* Absolute time */
526 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
527 print_graph_abs_time(iter->ts, s);
528
529 /* Relative time */
530 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
531 print_graph_rel_time(iter, s);
532
533 /* Cpu */
534 if (flags & TRACE_GRAPH_PRINT_CPU)
535 print_graph_cpu(s, cpu);
536
537 /* Proc */
538 if (flags & TRACE_GRAPH_PRINT_PROC) {
539 print_graph_proc(s, pid);
540 trace_seq_puts(s, " | ");
541 }
542
543 /* Latency format */
544 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
545 print_graph_lat_fmt(s, ent);
546 }
547
548 /* No overhead */
549 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_START);
550
551 if (type == TRACE_GRAPH_ENT)
552 trace_seq_puts(s, "==========>");
553 else
554 trace_seq_puts(s, "<==========");
555
556 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_END);
557 trace_seq_putc(s, '\n');
558}
559
560void
561trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
562{
563 unsigned long nsecs_rem = do_div(duration, 1000);
564 /* log10(ULONG_MAX) + '\0' */
565 char usecs_str[21];
566 char nsecs_str[5];
567 int len;
568 int i;
569
570 sprintf(usecs_str, "%lu", (unsigned long) duration);
571
572 /* Print msecs */
573 trace_seq_printf(s, "%s", usecs_str);
574
575 len = strlen(usecs_str);
576
577 /* Print nsecs (we don't want to exceed 7 numbers) */
578 if (len < 7) {
579 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
580
581 snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
582 trace_seq_printf(s, ".%s", nsecs_str);
583 len += strlen(nsecs_str) + 1;
584 }
585
586 trace_seq_puts(s, " us ");
587
588 /* Print remaining spaces to fit the row's width */
589 for (i = len; i < 8; i++)
590 trace_seq_putc(s, ' ');
591}
592
593static void
594print_graph_duration(struct trace_array *tr, unsigned long long duration,
595 struct trace_seq *s, u32 flags)
596{
597 if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
598 !(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
599 return;
600
601 /* No real adata, just filling the column with spaces */
602 switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
603 case FLAGS_FILL_FULL:
604 trace_seq_puts(s, " | ");
605 return;
606 case FLAGS_FILL_START:
607 trace_seq_puts(s, " ");
608 return;
609 case FLAGS_FILL_END:
610 trace_seq_puts(s, " |");
611 return;
612 }
613
614 /* Signal a overhead of time execution to the output */
615 if (flags & TRACE_GRAPH_PRINT_OVERHEAD)
616 trace_seq_printf(s, "%c ", trace_find_mark(duration));
617 else
618 trace_seq_puts(s, " ");
619
620 trace_print_graph_duration(duration, s);
621 trace_seq_puts(s, "| ");
622}
623
624/* Case of a leaf function on its call entry */
625static enum print_line_t
626print_graph_entry_leaf(struct trace_iterator *iter,
627 struct ftrace_graph_ent_entry *entry,
628 struct ftrace_graph_ret_entry *ret_entry,
629 struct trace_seq *s, u32 flags)
630{
631 struct fgraph_data *data = iter->private;
632 struct trace_array *tr = iter->tr;
633 struct ftrace_graph_ret *graph_ret;
634 struct ftrace_graph_ent *call;
635 unsigned long long duration;
636 int cpu = iter->cpu;
637 int i;
638
639 graph_ret = &ret_entry->ret;
640 call = &entry->graph_ent;
641 duration = graph_ret->rettime - graph_ret->calltime;
642
643 if (data) {
644 struct fgraph_cpu_data *cpu_data;
645
646 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
647
648 /*
649 * Comments display at + 1 to depth. Since
650 * this is a leaf function, keep the comments
651 * equal to this depth.
652 */
653 cpu_data->depth = call->depth - 1;
654
655 /* No need to keep this function around for this depth */
656 if (call->depth < FTRACE_RETFUNC_DEPTH &&
657 !WARN_ON_ONCE(call->depth < 0))
658 cpu_data->enter_funcs[call->depth] = 0;
659 }
660
661 /* Overhead and duration */
662 print_graph_duration(tr, duration, s, flags);
663
664 /* Function */
665 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
666 trace_seq_putc(s, ' ');
667
668 trace_seq_printf(s, "%ps();\n", (void *)call->func);
669
670 print_graph_irq(iter, graph_ret->func, TRACE_GRAPH_RET,
671 cpu, iter->ent->pid, flags);
672
673 return trace_handle_return(s);
674}
675
676static enum print_line_t
677print_graph_entry_nested(struct trace_iterator *iter,
678 struct ftrace_graph_ent_entry *entry,
679 struct trace_seq *s, int cpu, u32 flags)
680{
681 struct ftrace_graph_ent *call = &entry->graph_ent;
682 struct fgraph_data *data = iter->private;
683 struct trace_array *tr = iter->tr;
684 int i;
685
686 if (data) {
687 struct fgraph_cpu_data *cpu_data;
688 int cpu = iter->cpu;
689
690 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
691 cpu_data->depth = call->depth;
692
693 /* Save this function pointer to see if the exit matches */
694 if (call->depth < FTRACE_RETFUNC_DEPTH &&
695 !WARN_ON_ONCE(call->depth < 0))
696 cpu_data->enter_funcs[call->depth] = call->func;
697 }
698
699 /* No time */
700 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
701
702 /* Function */
703 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
704 trace_seq_putc(s, ' ');
705
706 trace_seq_printf(s, "%ps() {\n", (void *)call->func);
707
708 if (trace_seq_has_overflowed(s))
709 return TRACE_TYPE_PARTIAL_LINE;
710
711 /*
712 * we already consumed the current entry to check the next one
713 * and see if this is a leaf.
714 */
715 return TRACE_TYPE_NO_CONSUME;
716}
717
718static void
719print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
720 int type, unsigned long addr, u32 flags)
721{
722 struct fgraph_data *data = iter->private;
723 struct trace_entry *ent = iter->ent;
724 struct trace_array *tr = iter->tr;
725 int cpu = iter->cpu;
726
727 /* Pid */
728 verif_pid(s, ent->pid, cpu, data);
729
730 if (type)
731 /* Interrupt */
732 print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
733
734 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
735 return;
736
737 /* Absolute time */
738 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
739 print_graph_abs_time(iter->ts, s);
740
741 /* Relative time */
742 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
743 print_graph_rel_time(iter, s);
744
745 /* Cpu */
746 if (flags & TRACE_GRAPH_PRINT_CPU)
747 print_graph_cpu(s, cpu);
748
749 /* Proc */
750 if (flags & TRACE_GRAPH_PRINT_PROC) {
751 print_graph_proc(s, ent->pid);
752 trace_seq_puts(s, " | ");
753 }
754
755 /* Latency format */
756 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
757 print_graph_lat_fmt(s, ent);
758
759 return;
760}
761
762/*
763 * Entry check for irq code
764 *
765 * returns 1 if
766 * - we are inside irq code
767 * - we just entered irq code
768 *
769 * retunns 0 if
770 * - funcgraph-interrupts option is set
771 * - we are not inside irq code
772 */
773static int
774check_irq_entry(struct trace_iterator *iter, u32 flags,
775 unsigned long addr, int depth)
776{
777 int cpu = iter->cpu;
778 int *depth_irq;
779 struct fgraph_data *data = iter->private;
780
781 /*
782 * If we are either displaying irqs, or we got called as
783 * a graph event and private data does not exist,
784 * then we bypass the irq check.
785 */
786 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
787 (!data))
788 return 0;
789
790 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
791
792 /*
793 * We are inside the irq code
794 */
795 if (*depth_irq >= 0)
796 return 1;
797
798 if ((addr < (unsigned long)__irqentry_text_start) ||
799 (addr >= (unsigned long)__irqentry_text_end))
800 return 0;
801
802 /*
803 * We are entering irq code.
804 */
805 *depth_irq = depth;
806 return 1;
807}
808
809/*
810 * Return check for irq code
811 *
812 * returns 1 if
813 * - we are inside irq code
814 * - we just left irq code
815 *
816 * returns 0 if
817 * - funcgraph-interrupts option is set
818 * - we are not inside irq code
819 */
820static int
821check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
822{
823 int cpu = iter->cpu;
824 int *depth_irq;
825 struct fgraph_data *data = iter->private;
826
827 /*
828 * If we are either displaying irqs, or we got called as
829 * a graph event and private data does not exist,
830 * then we bypass the irq check.
831 */
832 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
833 (!data))
834 return 0;
835
836 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
837
838 /*
839 * We are not inside the irq code.
840 */
841 if (*depth_irq == -1)
842 return 0;
843
844 /*
845 * We are inside the irq code, and this is returning entry.
846 * Let's not trace it and clear the entry depth, since
847 * we are out of irq code.
848 *
849 * This condition ensures that we 'leave the irq code' once
850 * we are out of the entry depth. Thus protecting us from
851 * the RETURN entry loss.
852 */
853 if (*depth_irq >= depth) {
854 *depth_irq = -1;
855 return 1;
856 }
857
858 /*
859 * We are inside the irq code, and this is not the entry.
860 */
861 return 1;
862}
863
864static enum print_line_t
865print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
866 struct trace_iterator *iter, u32 flags)
867{
868 struct fgraph_data *data = iter->private;
869 struct ftrace_graph_ent *call = &field->graph_ent;
870 struct ftrace_graph_ret_entry *leaf_ret;
871 static enum print_line_t ret;
872 int cpu = iter->cpu;
873
874 if (check_irq_entry(iter, flags, call->func, call->depth))
875 return TRACE_TYPE_HANDLED;
876
877 print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags);
878
879 leaf_ret = get_return_for_leaf(iter, field);
880 if (leaf_ret)
881 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
882 else
883 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
884
885 if (data) {
886 /*
887 * If we failed to write our output, then we need to make
888 * note of it. Because we already consumed our entry.
889 */
890 if (s->full) {
891 data->failed = 1;
892 data->cpu = cpu;
893 } else
894 data->failed = 0;
895 }
896
897 return ret;
898}
899
900static enum print_line_t
901print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
902 struct trace_entry *ent, struct trace_iterator *iter,
903 u32 flags)
904{
905 unsigned long long duration = trace->rettime - trace->calltime;
906 struct fgraph_data *data = iter->private;
907 struct trace_array *tr = iter->tr;
908 pid_t pid = ent->pid;
909 int cpu = iter->cpu;
910 int func_match = 1;
911 int i;
912
913 if (check_irq_return(iter, flags, trace->depth))
914 return TRACE_TYPE_HANDLED;
915
916 if (data) {
917 struct fgraph_cpu_data *cpu_data;
918 int cpu = iter->cpu;
919
920 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
921
922 /*
923 * Comments display at + 1 to depth. This is the
924 * return from a function, we now want the comments
925 * to display at the same level of the bracket.
926 */
927 cpu_data->depth = trace->depth - 1;
928
929 if (trace->depth < FTRACE_RETFUNC_DEPTH &&
930 !WARN_ON_ONCE(trace->depth < 0)) {
931 if (cpu_data->enter_funcs[trace->depth] != trace->func)
932 func_match = 0;
933 cpu_data->enter_funcs[trace->depth] = 0;
934 }
935 }
936
937 print_graph_prologue(iter, s, 0, 0, flags);
938
939 /* Overhead and duration */
940 print_graph_duration(tr, duration, s, flags);
941
942 /* Closing brace */
943 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++)
944 trace_seq_putc(s, ' ');
945
946 /*
947 * If the return function does not have a matching entry,
948 * then the entry was lost. Instead of just printing
949 * the '}' and letting the user guess what function this
950 * belongs to, write out the function name. Always do
951 * that if the funcgraph-tail option is enabled.
952 */
953 if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL))
954 trace_seq_puts(s, "}\n");
955 else
956 trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
957
958 /* Overrun */
959 if (flags & TRACE_GRAPH_PRINT_OVERRUN)
960 trace_seq_printf(s, " (Overruns: %lu)\n",
961 trace->overrun);
962
963 print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
964 cpu, pid, flags);
965
966 return trace_handle_return(s);
967}
968
969static enum print_line_t
970print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
971 struct trace_iterator *iter, u32 flags)
972{
973 struct trace_array *tr = iter->tr;
974 unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
975 struct fgraph_data *data = iter->private;
976 struct trace_event *event;
977 int depth = 0;
978 int ret;
979 int i;
980
981 if (data)
982 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
983
984 print_graph_prologue(iter, s, 0, 0, flags);
985
986 /* No time */
987 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
988
989 /* Indentation */
990 if (depth > 0)
991 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++)
992 trace_seq_putc(s, ' ');
993
994 /* The comment */
995 trace_seq_puts(s, "/* ");
996
997 switch (iter->ent->type) {
998 case TRACE_BPUTS:
999 ret = trace_print_bputs_msg_only(iter);
1000 if (ret != TRACE_TYPE_HANDLED)
1001 return ret;
1002 break;
1003 case TRACE_BPRINT:
1004 ret = trace_print_bprintk_msg_only(iter);
1005 if (ret != TRACE_TYPE_HANDLED)
1006 return ret;
1007 break;
1008 case TRACE_PRINT:
1009 ret = trace_print_printk_msg_only(iter);
1010 if (ret != TRACE_TYPE_HANDLED)
1011 return ret;
1012 break;
1013 default:
1014 event = ftrace_find_event(ent->type);
1015 if (!event)
1016 return TRACE_TYPE_UNHANDLED;
1017
1018 ret = event->funcs->trace(iter, sym_flags, event);
1019 if (ret != TRACE_TYPE_HANDLED)
1020 return ret;
1021 }
1022
1023 if (trace_seq_has_overflowed(s))
1024 goto out;
1025
1026 /* Strip ending newline */
1027 if (s->buffer[s->seq.len - 1] == '\n') {
1028 s->buffer[s->seq.len - 1] = '\0';
1029 s->seq.len--;
1030 }
1031
1032 trace_seq_puts(s, " */\n");
1033 out:
1034 return trace_handle_return(s);
1035}
1036
1037
1038enum print_line_t
1039print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1040{
1041 struct ftrace_graph_ent_entry *field;
1042 struct fgraph_data *data = iter->private;
1043 struct trace_entry *entry = iter->ent;
1044 struct trace_seq *s = &iter->seq;
1045 int cpu = iter->cpu;
1046 int ret;
1047
1048 if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1049 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1050 return TRACE_TYPE_HANDLED;
1051 }
1052
1053 /*
1054 * If the last output failed, there's a possibility we need
1055 * to print out the missing entry which would never go out.
1056 */
1057 if (data && data->failed) {
1058 field = &data->ent;
1059 iter->cpu = data->cpu;
1060 ret = print_graph_entry(field, s, iter, flags);
1061 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1062 per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1063 ret = TRACE_TYPE_NO_CONSUME;
1064 }
1065 iter->cpu = cpu;
1066 return ret;
1067 }
1068
1069 switch (entry->type) {
1070 case TRACE_GRAPH_ENT: {
1071 /*
1072 * print_graph_entry() may consume the current event,
1073 * thus @field may become invalid, so we need to save it.
1074 * sizeof(struct ftrace_graph_ent_entry) is very small,
1075 * it can be safely saved at the stack.
1076 */
1077 struct ftrace_graph_ent_entry saved;
1078 trace_assign_type(field, entry);
1079 saved = *field;
1080 return print_graph_entry(&saved, s, iter, flags);
1081 }
1082 case TRACE_GRAPH_RET: {
1083 struct ftrace_graph_ret_entry *field;
1084 trace_assign_type(field, entry);
1085 return print_graph_return(&field->ret, s, entry, iter, flags);
1086 }
1087 case TRACE_STACK:
1088 case TRACE_FN:
1089 /* dont trace stack and functions as comments */
1090 return TRACE_TYPE_UNHANDLED;
1091
1092 default:
1093 return print_graph_comment(s, entry, iter, flags);
1094 }
1095
1096 return TRACE_TYPE_HANDLED;
1097}
1098
1099static enum print_line_t
1100print_graph_function(struct trace_iterator *iter)
1101{
1102 return print_graph_function_flags(iter, tracer_flags.val);
1103}
1104
1105static enum print_line_t
1106print_graph_function_event(struct trace_iterator *iter, int flags,
1107 struct trace_event *event)
1108{
1109 return print_graph_function(iter);
1110}
1111
1112static void print_lat_header(struct seq_file *s, u32 flags)
1113{
1114 static const char spaces[] = " " /* 16 spaces */
1115 " " /* 4 spaces */
1116 " "; /* 17 spaces */
1117 int size = 0;
1118
1119 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1120 size += 16;
1121 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1122 size += 16;
1123 if (flags & TRACE_GRAPH_PRINT_CPU)
1124 size += 4;
1125 if (flags & TRACE_GRAPH_PRINT_PROC)
1126 size += 17;
1127
1128 seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces);
1129 seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
1130 seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1131 seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
1132 seq_printf(s, "#%.*s||| / \n", size, spaces);
1133}
1134
1135static void __print_graph_headers_flags(struct trace_array *tr,
1136 struct seq_file *s, u32 flags)
1137{
1138 int lat = tr->trace_flags & TRACE_ITER_LATENCY_FMT;
1139
1140 if (lat)
1141 print_lat_header(s, flags);
1142
1143 /* 1st line */
1144 seq_putc(s, '#');
1145 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1146 seq_puts(s, " TIME ");
1147 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1148 seq_puts(s, " REL TIME ");
1149 if (flags & TRACE_GRAPH_PRINT_CPU)
1150 seq_puts(s, " CPU");
1151 if (flags & TRACE_GRAPH_PRINT_PROC)
1152 seq_puts(s, " TASK/PID ");
1153 if (lat)
1154 seq_puts(s, "|||| ");
1155 if (flags & TRACE_GRAPH_PRINT_DURATION)
1156 seq_puts(s, " DURATION ");
1157 seq_puts(s, " FUNCTION CALLS\n");
1158
1159 /* 2nd line */
1160 seq_putc(s, '#');
1161 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1162 seq_puts(s, " | ");
1163 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1164 seq_puts(s, " | ");
1165 if (flags & TRACE_GRAPH_PRINT_CPU)
1166 seq_puts(s, " | ");
1167 if (flags & TRACE_GRAPH_PRINT_PROC)
1168 seq_puts(s, " | | ");
1169 if (lat)
1170 seq_puts(s, "|||| ");
1171 if (flags & TRACE_GRAPH_PRINT_DURATION)
1172 seq_puts(s, " | | ");
1173 seq_puts(s, " | | | |\n");
1174}
1175
1176static void print_graph_headers(struct seq_file *s)
1177{
1178 print_graph_headers_flags(s, tracer_flags.val);
1179}
1180
1181void print_graph_headers_flags(struct seq_file *s, u32 flags)
1182{
1183 struct trace_iterator *iter = s->private;
1184 struct trace_array *tr = iter->tr;
1185
1186 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
1187 return;
1188
1189 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) {
1190 /* print nothing if the buffers are empty */
1191 if (trace_empty(iter))
1192 return;
1193
1194 print_trace_header(s, iter);
1195 }
1196
1197 __print_graph_headers_flags(tr, s, flags);
1198}
1199
1200void graph_trace_open(struct trace_iterator *iter)
1201{
1202 /* pid and depth on the last trace processed */
1203 struct fgraph_data *data;
1204 gfp_t gfpflags;
1205 int cpu;
1206
1207 iter->private = NULL;
1208
1209 /* We can be called in atomic context via ftrace_dump() */
1210 gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL;
1211
1212 data = kzalloc(sizeof(*data), gfpflags);
1213 if (!data)
1214 goto out_err;
1215
1216 data->cpu_data = alloc_percpu_gfp(struct fgraph_cpu_data, gfpflags);
1217 if (!data->cpu_data)
1218 goto out_err_free;
1219
1220 for_each_possible_cpu(cpu) {
1221 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1222 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1223 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1224 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1225
1226 *pid = -1;
1227 *depth = 0;
1228 *ignore = 0;
1229 *depth_irq = -1;
1230 }
1231
1232 iter->private = data;
1233
1234 return;
1235
1236 out_err_free:
1237 kfree(data);
1238 out_err:
1239 pr_warn("function graph tracer: not enough memory\n");
1240}
1241
1242void graph_trace_close(struct trace_iterator *iter)
1243{
1244 struct fgraph_data *data = iter->private;
1245
1246 if (data) {
1247 free_percpu(data->cpu_data);
1248 kfree(data);
1249 }
1250}
1251
1252static int
1253func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
1254{
1255 if (bit == TRACE_GRAPH_PRINT_IRQS)
1256 ftrace_graph_skip_irqs = !set;
1257
1258 if (bit == TRACE_GRAPH_SLEEP_TIME)
1259 ftrace_graph_sleep_time_control(set);
1260
1261 if (bit == TRACE_GRAPH_GRAPH_TIME)
1262 ftrace_graph_graph_time_control(set);
1263
1264 return 0;
1265}
1266
1267static struct trace_event_functions graph_functions = {
1268 .trace = print_graph_function_event,
1269};
1270
1271static struct trace_event graph_trace_entry_event = {
1272 .type = TRACE_GRAPH_ENT,
1273 .funcs = &graph_functions,
1274};
1275
1276static struct trace_event graph_trace_ret_event = {
1277 .type = TRACE_GRAPH_RET,
1278 .funcs = &graph_functions
1279};
1280
1281static struct tracer graph_trace __tracer_data = {
1282 .name = "function_graph",
1283 .update_thresh = graph_trace_update_thresh,
1284 .open = graph_trace_open,
1285 .pipe_open = graph_trace_open,
1286 .close = graph_trace_close,
1287 .pipe_close = graph_trace_close,
1288 .init = graph_trace_init,
1289 .reset = graph_trace_reset,
1290 .print_line = print_graph_function,
1291 .print_header = print_graph_headers,
1292 .flags = &tracer_flags,
1293 .set_flag = func_graph_set_flag,
1294#ifdef CONFIG_FTRACE_SELFTEST
1295 .selftest = trace_selftest_startup_function_graph,
1296#endif
1297};
1298
1299
1300static ssize_t
1301graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
1302 loff_t *ppos)
1303{
1304 unsigned long val;
1305 int ret;
1306
1307 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1308 if (ret)
1309 return ret;
1310
1311 fgraph_max_depth = val;
1312
1313 *ppos += cnt;
1314
1315 return cnt;
1316}
1317
1318static ssize_t
1319graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
1320 loff_t *ppos)
1321{
1322 char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/
1323 int n;
1324
1325 n = sprintf(buf, "%d\n", fgraph_max_depth);
1326
1327 return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
1328}
1329
1330static const struct file_operations graph_depth_fops = {
1331 .open = tracing_open_generic,
1332 .write = graph_depth_write,
1333 .read = graph_depth_read,
1334 .llseek = generic_file_llseek,
1335};
1336
1337static __init int init_graph_tracefs(void)
1338{
1339 struct dentry *d_tracer;
1340
1341 d_tracer = tracing_init_dentry();
1342 if (IS_ERR(d_tracer))
1343 return 0;
1344
1345 trace_create_file("max_graph_depth", 0644, d_tracer,
1346 NULL, &graph_depth_fops);
1347
1348 return 0;
1349}
1350fs_initcall(init_graph_tracefs);
1351
1352static __init int init_graph_trace(void)
1353{
1354 max_bytes_for_cpu = snprintf(NULL, 0, "%u", nr_cpu_ids - 1);
1355
1356 if (!register_trace_event(&graph_trace_entry_event)) {
1357 pr_warn("Warning: could not register graph trace events\n");
1358 return 1;
1359 }
1360
1361 if (!register_trace_event(&graph_trace_ret_event)) {
1362 pr_warn("Warning: could not register graph trace events\n");
1363 return 1;
1364 }
1365
1366 return register_tracer(&graph_trace);
1367}
1368
1369core_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);