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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
19static bool kill_ftrace_graph;
20
21
22
23
24
25
26
27
28bool ftrace_graph_is_dead(void)
29{
30 return kill_ftrace_graph;
31}
32
33
34
35
36
37
38
39
40
41void ftrace_graph_stop(void)
42{
43 kill_ftrace_graph = true;
44}
45
46
47static int ftrace_graph_skip_irqs;
48
49struct fgraph_cpu_data {
50 pid_t last_pid;
51 int depth;
52 int depth_irq;
53 int ignore;
54 unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH];
55};
56
57struct fgraph_data {
58 struct fgraph_cpu_data __percpu *cpu_data;
59
60
61 struct ftrace_graph_ent_entry ent;
62 struct ftrace_graph_ret_entry ret;
63 int failed;
64 int cpu;
65};
66
67#define TRACE_GRAPH_INDENT 2
68
69unsigned int fgraph_max_depth;
70
71static struct tracer_opt trace_opts[] = {
72
73 { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
74
75 { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
76
77 { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
78
79 { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
80
81 { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
82
83 { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
84
85 { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
86
87 { TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) },
88
89 { TRACER_OPT(sleep-time, TRACE_GRAPH_SLEEP_TIME) },
90
91 { TRACER_OPT(graph-time, TRACE_GRAPH_GRAPH_TIME) },
92 { }
93};
94
95static struct tracer_flags tracer_flags = {
96
97 .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
98 TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS |
99 TRACE_GRAPH_SLEEP_TIME | TRACE_GRAPH_GRAPH_TIME,
100 .opts = trace_opts
101};
102
103static struct trace_array *graph_array;
104
105
106
107
108
109
110enum {
111 FLAGS_FILL_FULL = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT,
112 FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT,
113 FLAGS_FILL_END = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT,
114};
115
116static void
117print_graph_duration(struct trace_array *tr, unsigned long long duration,
118 struct trace_seq *s, u32 flags);
119
120
121int
122ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
123 unsigned long frame_pointer, unsigned long *retp)
124{
125 unsigned long long calltime;
126 int index;
127
128 if (unlikely(ftrace_graph_is_dead()))
129 return -EBUSY;
130
131 if (!current->ret_stack)
132 return -EBUSY;
133
134
135
136
137
138 smp_rmb();
139
140
141 if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
142 atomic_inc(¤t->trace_overrun);
143 return -EBUSY;
144 }
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162 if (current->curr_ret_stack < -1)
163 return -EBUSY;
164
165 calltime = trace_clock_local();
166
167 index = ++current->curr_ret_stack;
168 if (ftrace_graph_notrace_addr(func))
169 current->curr_ret_stack -= FTRACE_NOTRACE_DEPTH;
170 barrier();
171 current->ret_stack[index].ret = ret;
172 current->ret_stack[index].func = func;
173 current->ret_stack[index].calltime = calltime;
174#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
175 current->ret_stack[index].fp = frame_pointer;
176#endif
177#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
178 current->ret_stack[index].retp = retp;
179#endif
180 *depth = current->curr_ret_stack;
181
182 return 0;
183}
184
185
186static void
187ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
188 unsigned long frame_pointer)
189{
190 int index;
191
192 index = current->curr_ret_stack;
193
194
195
196
197
198
199
200
201 if (index < 0)
202 index += FTRACE_NOTRACE_DEPTH;
203
204 if (unlikely(index < 0 || index >= FTRACE_RETFUNC_DEPTH)) {
205 ftrace_graph_stop();
206 WARN_ON(1);
207
208 *ret = (unsigned long)panic;
209 return;
210 }
211
212#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227 if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
228 ftrace_graph_stop();
229 WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
230 " from func %ps return to %lx\n",
231 current->ret_stack[index].fp,
232 frame_pointer,
233 (void *)current->ret_stack[index].func,
234 current->ret_stack[index].ret);
235 *ret = (unsigned long)panic;
236 return;
237 }
238#endif
239
240 *ret = current->ret_stack[index].ret;
241 trace->func = current->ret_stack[index].func;
242 trace->calltime = current->ret_stack[index].calltime;
243 trace->overrun = atomic_read(¤t->trace_overrun);
244 trace->depth = index;
245}
246
247
248
249
250
251unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
252{
253 struct ftrace_graph_ret trace;
254 unsigned long ret;
255
256 ftrace_pop_return_trace(&trace, &ret, frame_pointer);
257 trace.rettime = trace_clock_local();
258 barrier();
259 current->curr_ret_stack--;
260
261
262
263
264
265 if (current->curr_ret_stack < -1) {
266 current->curr_ret_stack += FTRACE_NOTRACE_DEPTH;
267 return ret;
268 }
269
270
271
272
273
274
275 ftrace_graph_return(&trace);
276
277 if (unlikely(!ret)) {
278 ftrace_graph_stop();
279 WARN_ON(1);
280
281 ret = (unsigned long)panic;
282 }
283
284 return ret;
285}
286
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299
300
301
302#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
303unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
304 unsigned long ret, unsigned long *retp)
305{
306 int index = task->curr_ret_stack;
307 int i;
308
309 if (ret != (unsigned long)return_to_handler)
310 return ret;
311
312 if (index < -1)
313 index += FTRACE_NOTRACE_DEPTH;
314
315 if (index < 0)
316 return ret;
317
318 for (i = 0; i <= index; i++)
319 if (task->ret_stack[i].retp == retp)
320 return task->ret_stack[i].ret;
321
322 return ret;
323}
324#else
325unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
326 unsigned long ret, unsigned long *retp)
327{
328 int task_idx;
329
330 if (ret != (unsigned long)return_to_handler)
331 return ret;
332
333 task_idx = task->curr_ret_stack;
334
335 if (!task->ret_stack || task_idx < *idx)
336 return ret;
337
338 task_idx -= *idx;
339 (*idx)++;
340
341 return task->ret_stack[task_idx].ret;
342}
343#endif
344
345int __trace_graph_entry(struct trace_array *tr,
346 struct ftrace_graph_ent *trace,
347 unsigned long flags,
348 int pc)
349{
350 struct trace_event_call *call = &event_funcgraph_entry;
351 struct ring_buffer_event *event;
352 struct ring_buffer *buffer = tr->trace_buffer.buffer;
353 struct ftrace_graph_ent_entry *entry;
354
355 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
356 sizeof(*entry), flags, pc);
357 if (!event)
358 return 0;
359 entry = ring_buffer_event_data(event);
360 entry->graph_ent = *trace;
361 if (!call_filter_check_discard(call, entry, buffer, event))
362 trace_buffer_unlock_commit_nostack(buffer, event);
363
364 return 1;
365}
366
367static inline int ftrace_graph_ignore_irqs(void)
368{
369 if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
370 return 0;
371
372 return in_irq();
373}
374
375int trace_graph_entry(struct ftrace_graph_ent *trace)
376{
377 struct trace_array *tr = graph_array;
378 struct trace_array_cpu *data;
379 unsigned long flags;
380 long disabled;
381 int ret;
382 int cpu;
383 int pc;
384
385 if (!ftrace_trace_task(tr))
386 return 0;
387
388 if (ftrace_graph_ignore_func(trace))
389 return 0;
390
391 if (ftrace_graph_ignore_irqs())
392 return 0;
393
394
395
396
397
398
399
400
401 if (ftrace_graph_notrace_addr(trace->func))
402 return 1;
403
404
405
406
407
408 if (tracing_thresh)
409 return 1;
410
411 local_irq_save(flags);
412 cpu = raw_smp_processor_id();
413 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
414 disabled = atomic_inc_return(&data->disabled);
415 if (likely(disabled == 1)) {
416 pc = preempt_count();
417 ret = __trace_graph_entry(tr, trace, flags, pc);
418 } else {
419 ret = 0;
420 }
421
422 atomic_dec(&data->disabled);
423 local_irq_restore(flags);
424
425 return ret;
426}
427
428static void
429__trace_graph_function(struct trace_array *tr,
430 unsigned long ip, unsigned long flags, int pc)
431{
432 u64 time = trace_clock_local();
433 struct ftrace_graph_ent ent = {
434 .func = ip,
435 .depth = 0,
436 };
437 struct ftrace_graph_ret ret = {
438 .func = ip,
439 .depth = 0,
440 .calltime = time,
441 .rettime = time,
442 };
443
444 __trace_graph_entry(tr, &ent, flags, pc);
445 __trace_graph_return(tr, &ret, flags, pc);
446}
447
448void
449trace_graph_function(struct trace_array *tr,
450 unsigned long ip, unsigned long parent_ip,
451 unsigned long flags, int pc)
452{
453 __trace_graph_function(tr, ip, flags, pc);
454}
455
456void __trace_graph_return(struct trace_array *tr,
457 struct ftrace_graph_ret *trace,
458 unsigned long flags,
459 int pc)
460{
461 struct trace_event_call *call = &event_funcgraph_exit;
462 struct ring_buffer_event *event;
463 struct ring_buffer *buffer = tr->trace_buffer.buffer;
464 struct ftrace_graph_ret_entry *entry;
465
466 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
467 sizeof(*entry), flags, pc);
468 if (!event)
469 return;
470 entry = ring_buffer_event_data(event);
471 entry->ret = *trace;
472 if (!call_filter_check_discard(call, entry, buffer, event))
473 trace_buffer_unlock_commit_nostack(buffer, event);
474}
475
476void trace_graph_return(struct ftrace_graph_ret *trace)
477{
478 struct trace_array *tr = graph_array;
479 struct trace_array_cpu *data;
480 unsigned long flags;
481 long disabled;
482 int cpu;
483 int pc;
484
485 local_irq_save(flags);
486 cpu = raw_smp_processor_id();
487 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
488 disabled = atomic_inc_return(&data->disabled);
489 if (likely(disabled == 1)) {
490 pc = preempt_count();
491 __trace_graph_return(tr, trace, flags, pc);
492 }
493 atomic_dec(&data->disabled);
494 local_irq_restore(flags);
495}
496
497void set_graph_array(struct trace_array *tr)
498{
499 graph_array = tr;
500
501
502
503 smp_mb();
504}
505
506static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
507{
508 if (tracing_thresh &&
509 (trace->rettime - trace->calltime < tracing_thresh))
510 return;
511 else
512 trace_graph_return(trace);
513}
514
515static int graph_trace_init(struct trace_array *tr)
516{
517 int ret;
518
519 set_graph_array(tr);
520 if (tracing_thresh)
521 ret = register_ftrace_graph(&trace_graph_thresh_return,
522 &trace_graph_entry);
523 else
524 ret = register_ftrace_graph(&trace_graph_return,
525 &trace_graph_entry);
526 if (ret)
527 return ret;
528 tracing_start_cmdline_record();
529
530 return 0;
531}
532
533static void graph_trace_reset(struct trace_array *tr)
534{
535 tracing_stop_cmdline_record();
536 unregister_ftrace_graph();
537}
538
539static int graph_trace_update_thresh(struct trace_array *tr)
540{
541 graph_trace_reset(tr);
542 return graph_trace_init(tr);
543}
544
545static int max_bytes_for_cpu;
546
547static void print_graph_cpu(struct trace_seq *s, int cpu)
548{
549
550
551
552
553
554 trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
555}
556
557#define TRACE_GRAPH_PROCINFO_LENGTH 14
558
559static void print_graph_proc(struct trace_seq *s, pid_t pid)
560{
561 char comm[TASK_COMM_LEN];
562
563 char pid_str[11];
564 int spaces = 0;
565 int len;
566 int i;
567
568 trace_find_cmdline(pid, comm);
569 comm[7] = '\0';
570 sprintf(pid_str, "%d", pid);
571
572
573 len = strlen(comm) + strlen(pid_str) + 1;
574
575 if (len < TRACE_GRAPH_PROCINFO_LENGTH)
576 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
577
578
579 for (i = 0; i < spaces / 2; i++)
580 trace_seq_putc(s, ' ');
581
582 trace_seq_printf(s, "%s-%s", comm, pid_str);
583
584
585 for (i = 0; i < spaces - (spaces / 2); i++)
586 trace_seq_putc(s, ' ');
587}
588
589
590static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
591{
592 trace_seq_putc(s, ' ');
593 trace_print_lat_fmt(s, entry);
594}
595
596
597static void
598verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
599{
600 pid_t prev_pid;
601 pid_t *last_pid;
602
603 if (!data)
604 return;
605
606 last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
607
608 if (*last_pid == pid)
609 return;
610
611 prev_pid = *last_pid;
612 *last_pid = pid;
613
614 if (prev_pid == -1)
615 return;
616
617
618
619
620
621
622
623
624 trace_seq_puts(s, " ------------------------------------------\n");
625 print_graph_cpu(s, cpu);
626 print_graph_proc(s, prev_pid);
627 trace_seq_puts(s, " => ");
628 print_graph_proc(s, pid);
629 trace_seq_puts(s, "\n ------------------------------------------\n\n");
630}
631
632static struct ftrace_graph_ret_entry *
633get_return_for_leaf(struct trace_iterator *iter,
634 struct ftrace_graph_ent_entry *curr)
635{
636 struct fgraph_data *data = iter->private;
637 struct ring_buffer_iter *ring_iter = NULL;
638 struct ring_buffer_event *event;
639 struct ftrace_graph_ret_entry *next;
640
641
642
643
644
645 if (data && data->failed) {
646 curr = &data->ent;
647 next = &data->ret;
648 } else {
649
650 ring_iter = trace_buffer_iter(iter, iter->cpu);
651
652
653 if (ring_iter)
654 event = ring_buffer_iter_peek(ring_iter, NULL);
655 else {
656
657
658
659
660 ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu,
661 NULL, NULL);
662 event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu,
663 NULL, NULL);
664 }
665
666 if (!event)
667 return NULL;
668
669 next = ring_buffer_event_data(event);
670
671 if (data) {
672
673
674
675
676 data->ent = *curr;
677
678
679
680
681
682 if (next->ent.type == TRACE_GRAPH_RET)
683 data->ret = *next;
684 else
685 data->ret.ent.type = next->ent.type;
686 }
687 }
688
689 if (next->ent.type != TRACE_GRAPH_RET)
690 return NULL;
691
692 if (curr->ent.pid != next->ent.pid ||
693 curr->graph_ent.func != next->ret.func)
694 return NULL;
695
696
697 if (ring_iter)
698 ring_buffer_read(ring_iter, NULL);
699
700 return next;
701}
702
703static void print_graph_abs_time(u64 t, struct trace_seq *s)
704{
705 unsigned long usecs_rem;
706
707 usecs_rem = do_div(t, NSEC_PER_SEC);
708 usecs_rem /= 1000;
709
710 trace_seq_printf(s, "%5lu.%06lu | ",
711 (unsigned long)t, usecs_rem);
712}
713
714static void
715print_graph_irq(struct trace_iterator *iter, unsigned long addr,
716 enum trace_type type, int cpu, pid_t pid, u32 flags)
717{
718 struct trace_array *tr = iter->tr;
719 struct trace_seq *s = &iter->seq;
720 struct trace_entry *ent = iter->ent;
721
722 if (addr < (unsigned long)__irqentry_text_start ||
723 addr >= (unsigned long)__irqentry_text_end)
724 return;
725
726 if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
727
728 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
729 print_graph_abs_time(iter->ts, s);
730
731
732 if (flags & TRACE_GRAPH_PRINT_CPU)
733 print_graph_cpu(s, cpu);
734
735
736 if (flags & TRACE_GRAPH_PRINT_PROC) {
737 print_graph_proc(s, pid);
738 trace_seq_puts(s, " | ");
739 }
740
741
742 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
743 print_graph_lat_fmt(s, ent);
744 }
745
746
747 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_START);
748
749 if (type == TRACE_GRAPH_ENT)
750 trace_seq_puts(s, "==========>");
751 else
752 trace_seq_puts(s, "<==========");
753
754 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_END);
755 trace_seq_putc(s, '\n');
756}
757
758void
759trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
760{
761 unsigned long nsecs_rem = do_div(duration, 1000);
762
763 char usecs_str[21];
764 char nsecs_str[5];
765 int len;
766 int i;
767
768 sprintf(usecs_str, "%lu", (unsigned long) duration);
769
770
771 trace_seq_printf(s, "%s", usecs_str);
772
773 len = strlen(usecs_str);
774
775
776 if (len < 7) {
777 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
778
779 snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
780 trace_seq_printf(s, ".%s", nsecs_str);
781 len += strlen(nsecs_str) + 1;
782 }
783
784 trace_seq_puts(s, " us ");
785
786
787 for (i = len; i < 8; i++)
788 trace_seq_putc(s, ' ');
789}
790
791static void
792print_graph_duration(struct trace_array *tr, unsigned long long duration,
793 struct trace_seq *s, u32 flags)
794{
795 if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
796 !(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
797 return;
798
799
800 switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
801 case FLAGS_FILL_FULL:
802 trace_seq_puts(s, " | ");
803 return;
804 case FLAGS_FILL_START:
805 trace_seq_puts(s, " ");
806 return;
807 case FLAGS_FILL_END:
808 trace_seq_puts(s, " |");
809 return;
810 }
811
812
813 if (flags & TRACE_GRAPH_PRINT_OVERHEAD)
814 trace_seq_printf(s, "%c ", trace_find_mark(duration));
815 else
816 trace_seq_puts(s, " ");
817
818 trace_print_graph_duration(duration, s);
819 trace_seq_puts(s, "| ");
820}
821
822
823static enum print_line_t
824print_graph_entry_leaf(struct trace_iterator *iter,
825 struct ftrace_graph_ent_entry *entry,
826 struct ftrace_graph_ret_entry *ret_entry,
827 struct trace_seq *s, u32 flags)
828{
829 struct fgraph_data *data = iter->private;
830 struct trace_array *tr = iter->tr;
831 struct ftrace_graph_ret *graph_ret;
832 struct ftrace_graph_ent *call;
833 unsigned long long duration;
834 int i;
835
836 graph_ret = &ret_entry->ret;
837 call = &entry->graph_ent;
838 duration = graph_ret->rettime - graph_ret->calltime;
839
840 if (data) {
841 struct fgraph_cpu_data *cpu_data;
842 int cpu = iter->cpu;
843
844 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
845
846
847 if (call->depth < -1)
848 call->depth += FTRACE_NOTRACE_DEPTH;
849
850
851
852
853
854
855 cpu_data->depth = call->depth - 1;
856
857
858 if (call->depth < FTRACE_RETFUNC_DEPTH &&
859 !WARN_ON_ONCE(call->depth < 0))
860 cpu_data->enter_funcs[call->depth] = 0;
861 }
862
863
864 print_graph_duration(tr, duration, s, flags);
865
866
867 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
868 trace_seq_putc(s, ' ');
869
870 trace_seq_printf(s, "%ps();\n", (void *)call->func);
871
872 return trace_handle_return(s);
873}
874
875static enum print_line_t
876print_graph_entry_nested(struct trace_iterator *iter,
877 struct ftrace_graph_ent_entry *entry,
878 struct trace_seq *s, int cpu, u32 flags)
879{
880 struct ftrace_graph_ent *call = &entry->graph_ent;
881 struct fgraph_data *data = iter->private;
882 struct trace_array *tr = iter->tr;
883 int i;
884
885 if (data) {
886 struct fgraph_cpu_data *cpu_data;
887 int cpu = iter->cpu;
888
889
890 if (call->depth < -1)
891 call->depth += FTRACE_NOTRACE_DEPTH;
892
893 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
894 cpu_data->depth = call->depth;
895
896
897 if (call->depth < FTRACE_RETFUNC_DEPTH &&
898 !WARN_ON_ONCE(call->depth < 0))
899 cpu_data->enter_funcs[call->depth] = call->func;
900 }
901
902
903 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
904
905
906 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
907 trace_seq_putc(s, ' ');
908
909 trace_seq_printf(s, "%ps() {\n", (void *)call->func);
910
911 if (trace_seq_has_overflowed(s))
912 return TRACE_TYPE_PARTIAL_LINE;
913
914
915
916
917
918 return TRACE_TYPE_NO_CONSUME;
919}
920
921static void
922print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
923 int type, unsigned long addr, u32 flags)
924{
925 struct fgraph_data *data = iter->private;
926 struct trace_entry *ent = iter->ent;
927 struct trace_array *tr = iter->tr;
928 int cpu = iter->cpu;
929
930
931 verif_pid(s, ent->pid, cpu, data);
932
933 if (type)
934
935 print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
936
937 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
938 return;
939
940
941 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
942 print_graph_abs_time(iter->ts, s);
943
944
945 if (flags & TRACE_GRAPH_PRINT_CPU)
946 print_graph_cpu(s, cpu);
947
948
949 if (flags & TRACE_GRAPH_PRINT_PROC) {
950 print_graph_proc(s, ent->pid);
951 trace_seq_puts(s, " | ");
952 }
953
954
955 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
956 print_graph_lat_fmt(s, ent);
957
958 return;
959}
960
961
962
963
964
965
966
967
968
969
970
971
972static int
973check_irq_entry(struct trace_iterator *iter, u32 flags,
974 unsigned long addr, int depth)
975{
976 int cpu = iter->cpu;
977 int *depth_irq;
978 struct fgraph_data *data = iter->private;
979
980
981
982
983
984
985 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
986 (!data))
987 return 0;
988
989 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
990
991
992
993
994 if (*depth_irq >= 0)
995 return 1;
996
997 if ((addr < (unsigned long)__irqentry_text_start) ||
998 (addr >= (unsigned long)__irqentry_text_end))
999 return 0;
1000
1001
1002
1003
1004 *depth_irq = depth;
1005 return 1;
1006}
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019static int
1020check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
1021{
1022 int cpu = iter->cpu;
1023 int *depth_irq;
1024 struct fgraph_data *data = iter->private;
1025
1026
1027
1028
1029
1030
1031 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
1032 (!data))
1033 return 0;
1034
1035 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1036
1037
1038
1039
1040 if (*depth_irq == -1)
1041 return 0;
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052 if (*depth_irq >= depth) {
1053 *depth_irq = -1;
1054 return 1;
1055 }
1056
1057
1058
1059
1060 return 1;
1061}
1062
1063static enum print_line_t
1064print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
1065 struct trace_iterator *iter, u32 flags)
1066{
1067 struct fgraph_data *data = iter->private;
1068 struct ftrace_graph_ent *call = &field->graph_ent;
1069 struct ftrace_graph_ret_entry *leaf_ret;
1070 static enum print_line_t ret;
1071 int cpu = iter->cpu;
1072
1073 if (check_irq_entry(iter, flags, call->func, call->depth))
1074 return TRACE_TYPE_HANDLED;
1075
1076 print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags);
1077
1078 leaf_ret = get_return_for_leaf(iter, field);
1079 if (leaf_ret)
1080 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
1081 else
1082 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
1083
1084 if (data) {
1085
1086
1087
1088
1089 if (s->full) {
1090 data->failed = 1;
1091 data->cpu = cpu;
1092 } else
1093 data->failed = 0;
1094 }
1095
1096 return ret;
1097}
1098
1099static enum print_line_t
1100print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
1101 struct trace_entry *ent, struct trace_iterator *iter,
1102 u32 flags)
1103{
1104 unsigned long long duration = trace->rettime - trace->calltime;
1105 struct fgraph_data *data = iter->private;
1106 struct trace_array *tr = iter->tr;
1107 pid_t pid = ent->pid;
1108 int cpu = iter->cpu;
1109 int func_match = 1;
1110 int i;
1111
1112 if (check_irq_return(iter, flags, trace->depth))
1113 return TRACE_TYPE_HANDLED;
1114
1115 if (data) {
1116 struct fgraph_cpu_data *cpu_data;
1117 int cpu = iter->cpu;
1118
1119 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1120
1121
1122
1123
1124
1125
1126 cpu_data->depth = trace->depth - 1;
1127
1128 if (trace->depth < FTRACE_RETFUNC_DEPTH &&
1129 !WARN_ON_ONCE(trace->depth < 0)) {
1130 if (cpu_data->enter_funcs[trace->depth] != trace->func)
1131 func_match = 0;
1132 cpu_data->enter_funcs[trace->depth] = 0;
1133 }
1134 }
1135
1136 print_graph_prologue(iter, s, 0, 0, flags);
1137
1138
1139 print_graph_duration(tr, duration, s, flags);
1140
1141
1142 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++)
1143 trace_seq_putc(s, ' ');
1144
1145
1146
1147
1148
1149
1150
1151
1152 if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL))
1153 trace_seq_puts(s, "}\n");
1154 else
1155 trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
1156
1157
1158 if (flags & TRACE_GRAPH_PRINT_OVERRUN)
1159 trace_seq_printf(s, " (Overruns: %lu)\n",
1160 trace->overrun);
1161
1162 print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
1163 cpu, pid, flags);
1164
1165 return trace_handle_return(s);
1166}
1167
1168static enum print_line_t
1169print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
1170 struct trace_iterator *iter, u32 flags)
1171{
1172 struct trace_array *tr = iter->tr;
1173 unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
1174 struct fgraph_data *data = iter->private;
1175 struct trace_event *event;
1176 int depth = 0;
1177 int ret;
1178 int i;
1179
1180 if (data)
1181 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
1182
1183 print_graph_prologue(iter, s, 0, 0, flags);
1184
1185
1186 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
1187
1188
1189 if (depth > 0)
1190 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++)
1191 trace_seq_putc(s, ' ');
1192
1193
1194 trace_seq_puts(s, "/* ");
1195
1196 switch (iter->ent->type) {
1197 case TRACE_BPUTS:
1198 ret = trace_print_bputs_msg_only(iter);
1199 if (ret != TRACE_TYPE_HANDLED)
1200 return ret;
1201 break;
1202 case TRACE_BPRINT:
1203 ret = trace_print_bprintk_msg_only(iter);
1204 if (ret != TRACE_TYPE_HANDLED)
1205 return ret;
1206 break;
1207 case TRACE_PRINT:
1208 ret = trace_print_printk_msg_only(iter);
1209 if (ret != TRACE_TYPE_HANDLED)
1210 return ret;
1211 break;
1212 default:
1213 event = ftrace_find_event(ent->type);
1214 if (!event)
1215 return TRACE_TYPE_UNHANDLED;
1216
1217 ret = event->funcs->trace(iter, sym_flags, event);
1218 if (ret != TRACE_TYPE_HANDLED)
1219 return ret;
1220 }
1221
1222 if (trace_seq_has_overflowed(s))
1223 goto out;
1224
1225
1226 if (s->buffer[s->seq.len - 1] == '\n') {
1227 s->buffer[s->seq.len - 1] = '\0';
1228 s->seq.len--;
1229 }
1230
1231 trace_seq_puts(s, " */\n");
1232 out:
1233 return trace_handle_return(s);
1234}
1235
1236
1237enum print_line_t
1238print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1239{
1240 struct ftrace_graph_ent_entry *field;
1241 struct fgraph_data *data = iter->private;
1242 struct trace_entry *entry = iter->ent;
1243 struct trace_seq *s = &iter->seq;
1244 int cpu = iter->cpu;
1245 int ret;
1246
1247 if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1248 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1249 return TRACE_TYPE_HANDLED;
1250 }
1251
1252
1253
1254
1255
1256 if (data && data->failed) {
1257 field = &data->ent;
1258 iter->cpu = data->cpu;
1259 ret = print_graph_entry(field, s, iter, flags);
1260 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1261 per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1262 ret = TRACE_TYPE_NO_CONSUME;
1263 }
1264 iter->cpu = cpu;
1265 return ret;
1266 }
1267
1268 switch (entry->type) {
1269 case TRACE_GRAPH_ENT: {
1270
1271
1272
1273
1274
1275
1276 struct ftrace_graph_ent_entry saved;
1277 trace_assign_type(field, entry);
1278 saved = *field;
1279 return print_graph_entry(&saved, s, iter, flags);
1280 }
1281 case TRACE_GRAPH_RET: {
1282 struct ftrace_graph_ret_entry *field;
1283 trace_assign_type(field, entry);
1284 return print_graph_return(&field->ret, s, entry, iter, flags);
1285 }
1286 case TRACE_STACK:
1287 case TRACE_FN:
1288
1289 return TRACE_TYPE_UNHANDLED;
1290
1291 default:
1292 return print_graph_comment(s, entry, iter, flags);
1293 }
1294
1295 return TRACE_TYPE_HANDLED;
1296}
1297
1298static enum print_line_t
1299print_graph_function(struct trace_iterator *iter)
1300{
1301 return print_graph_function_flags(iter, tracer_flags.val);
1302}
1303
1304static enum print_line_t
1305print_graph_function_event(struct trace_iterator *iter, int flags,
1306 struct trace_event *event)
1307{
1308 return print_graph_function(iter);
1309}
1310
1311static void print_lat_header(struct seq_file *s, u32 flags)
1312{
1313 static const char spaces[] = " "
1314 " "
1315 " ";
1316 int size = 0;
1317
1318 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1319 size += 16;
1320 if (flags & TRACE_GRAPH_PRINT_CPU)
1321 size += 4;
1322 if (flags & TRACE_GRAPH_PRINT_PROC)
1323 size += 17;
1324
1325 seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces);
1326 seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
1327 seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1328 seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
1329 seq_printf(s, "#%.*s||| / \n", size, spaces);
1330}
1331
1332static void __print_graph_headers_flags(struct trace_array *tr,
1333 struct seq_file *s, u32 flags)
1334{
1335 int lat = tr->trace_flags & TRACE_ITER_LATENCY_FMT;
1336
1337 if (lat)
1338 print_lat_header(s, flags);
1339
1340
1341 seq_putc(s, '#');
1342 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1343 seq_puts(s, " TIME ");
1344 if (flags & TRACE_GRAPH_PRINT_CPU)
1345 seq_puts(s, " CPU");
1346 if (flags & TRACE_GRAPH_PRINT_PROC)
1347 seq_puts(s, " TASK/PID ");
1348 if (lat)
1349 seq_puts(s, "||||");
1350 if (flags & TRACE_GRAPH_PRINT_DURATION)
1351 seq_puts(s, " DURATION ");
1352 seq_puts(s, " FUNCTION CALLS\n");
1353
1354
1355 seq_putc(s, '#');
1356 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1357 seq_puts(s, " | ");
1358 if (flags & TRACE_GRAPH_PRINT_CPU)
1359 seq_puts(s, " | ");
1360 if (flags & TRACE_GRAPH_PRINT_PROC)
1361 seq_puts(s, " | | ");
1362 if (lat)
1363 seq_puts(s, "||||");
1364 if (flags & TRACE_GRAPH_PRINT_DURATION)
1365 seq_puts(s, " | | ");
1366 seq_puts(s, " | | | |\n");
1367}
1368
1369static void print_graph_headers(struct seq_file *s)
1370{
1371 print_graph_headers_flags(s, tracer_flags.val);
1372}
1373
1374void print_graph_headers_flags(struct seq_file *s, u32 flags)
1375{
1376 struct trace_iterator *iter = s->private;
1377 struct trace_array *tr = iter->tr;
1378
1379 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
1380 return;
1381
1382 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) {
1383
1384 if (trace_empty(iter))
1385 return;
1386
1387 print_trace_header(s, iter);
1388 }
1389
1390 __print_graph_headers_flags(tr, s, flags);
1391}
1392
1393void graph_trace_open(struct trace_iterator *iter)
1394{
1395
1396 struct fgraph_data *data;
1397 gfp_t gfpflags;
1398 int cpu;
1399
1400 iter->private = NULL;
1401
1402
1403 gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL;
1404
1405 data = kzalloc(sizeof(*data), gfpflags);
1406 if (!data)
1407 goto out_err;
1408
1409 data->cpu_data = alloc_percpu_gfp(struct fgraph_cpu_data, gfpflags);
1410 if (!data->cpu_data)
1411 goto out_err_free;
1412
1413 for_each_possible_cpu(cpu) {
1414 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1415 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1416 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1417 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1418
1419 *pid = -1;
1420 *depth = 0;
1421 *ignore = 0;
1422 *depth_irq = -1;
1423 }
1424
1425 iter->private = data;
1426
1427 return;
1428
1429 out_err_free:
1430 kfree(data);
1431 out_err:
1432 pr_warn("function graph tracer: not enough memory\n");
1433}
1434
1435void graph_trace_close(struct trace_iterator *iter)
1436{
1437 struct fgraph_data *data = iter->private;
1438
1439 if (data) {
1440 free_percpu(data->cpu_data);
1441 kfree(data);
1442 }
1443}
1444
1445static int
1446func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
1447{
1448 if (bit == TRACE_GRAPH_PRINT_IRQS)
1449 ftrace_graph_skip_irqs = !set;
1450
1451 if (bit == TRACE_GRAPH_SLEEP_TIME)
1452 ftrace_graph_sleep_time_control(set);
1453
1454 if (bit == TRACE_GRAPH_GRAPH_TIME)
1455 ftrace_graph_graph_time_control(set);
1456
1457 return 0;
1458}
1459
1460static struct trace_event_functions graph_functions = {
1461 .trace = print_graph_function_event,
1462};
1463
1464static struct trace_event graph_trace_entry_event = {
1465 .type = TRACE_GRAPH_ENT,
1466 .funcs = &graph_functions,
1467};
1468
1469static struct trace_event graph_trace_ret_event = {
1470 .type = TRACE_GRAPH_RET,
1471 .funcs = &graph_functions
1472};
1473
1474static struct tracer graph_trace __tracer_data = {
1475 .name = "function_graph",
1476 .update_thresh = graph_trace_update_thresh,
1477 .open = graph_trace_open,
1478 .pipe_open = graph_trace_open,
1479 .close = graph_trace_close,
1480 .pipe_close = graph_trace_close,
1481 .init = graph_trace_init,
1482 .reset = graph_trace_reset,
1483 .print_line = print_graph_function,
1484 .print_header = print_graph_headers,
1485 .flags = &tracer_flags,
1486 .set_flag = func_graph_set_flag,
1487#ifdef CONFIG_FTRACE_SELFTEST
1488 .selftest = trace_selftest_startup_function_graph,
1489#endif
1490};
1491
1492
1493static ssize_t
1494graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
1495 loff_t *ppos)
1496{
1497 unsigned long val;
1498 int ret;
1499
1500 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1501 if (ret)
1502 return ret;
1503
1504 fgraph_max_depth = val;
1505
1506 *ppos += cnt;
1507
1508 return cnt;
1509}
1510
1511static ssize_t
1512graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
1513 loff_t *ppos)
1514{
1515 char buf[15];
1516 int n;
1517
1518 n = sprintf(buf, "%d\n", fgraph_max_depth);
1519
1520 return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
1521}
1522
1523static const struct file_operations graph_depth_fops = {
1524 .open = tracing_open_generic,
1525 .write = graph_depth_write,
1526 .read = graph_depth_read,
1527 .llseek = generic_file_llseek,
1528};
1529
1530static __init int init_graph_tracefs(void)
1531{
1532 struct dentry *d_tracer;
1533
1534 d_tracer = tracing_init_dentry();
1535 if (IS_ERR(d_tracer))
1536 return 0;
1537
1538 trace_create_file("max_graph_depth", 0644, d_tracer,
1539 NULL, &graph_depth_fops);
1540
1541 return 0;
1542}
1543fs_initcall(init_graph_tracefs);
1544
1545static __init int init_graph_trace(void)
1546{
1547 max_bytes_for_cpu = snprintf(NULL, 0, "%u", nr_cpu_ids - 1);
1548
1549 if (!register_trace_event(&graph_trace_entry_event)) {
1550 pr_warn("Warning: could not register graph trace events\n");
1551 return 1;
1552 }
1553
1554 if (!register_trace_event(&graph_trace_ret_event)) {
1555 pr_warn("Warning: could not register graph trace events\n");
1556 return 1;
1557 }
1558
1559 return register_tracer(&graph_trace);
1560}
1561
1562core_initcall(init_graph_trace);
1563