Merge branch '/tip/perf/filter' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6.git] / kernel / trace / trace_functions_graph.c
1 /*
2  *
3  * Function graph tracer.
4  * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
5  * Mostly borrowed from function tracer which
6  * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
7  *
8  */
9 #include <linux/debugfs.h>
10 #include <linux/uaccess.h>
11 #include <linux/ftrace.h>
12 #include <linux/slab.h>
13 #include <linux/fs.h>
14
15 #include "trace.h"
16 #include "trace_output.h"
17
18 /* When set, irq functions will be ignored */
19 static int ftrace_graph_skip_irqs;
20
21 struct fgraph_cpu_data {
22         pid_t           last_pid;
23         int             depth;
24         int             depth_irq;
25         int             ignore;
26         unsigned long   enter_funcs[FTRACE_RETFUNC_DEPTH];
27 };
28
29 struct fgraph_data {
30         struct fgraph_cpu_data __percpu *cpu_data;
31
32         /* Place to preserve last processed entry. */
33         struct ftrace_graph_ent_entry   ent;
34         struct ftrace_graph_ret_entry   ret;
35         int                             failed;
36         int                             cpu;
37 };
38
39 #define TRACE_GRAPH_INDENT      2
40
41 /* Flag options */
42 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
43 #define TRACE_GRAPH_PRINT_CPU           0x2
44 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
45 #define TRACE_GRAPH_PRINT_PROC          0x8
46 #define TRACE_GRAPH_PRINT_DURATION      0x10
47 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
48 #define TRACE_GRAPH_PRINT_IRQS          0x40
49
50 static struct tracer_opt trace_opts[] = {
51         /* Display overruns? (for self-debug purpose) */
52         { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
53         /* Display CPU ? */
54         { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
55         /* Display Overhead ? */
56         { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
57         /* Display proc name/pid */
58         { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
59         /* Display duration of execution */
60         { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
61         /* Display absolute time of an entry */
62         { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
63         /* Display interrupts */
64         { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
65         { } /* Empty entry */
66 };
67
68 static struct tracer_flags tracer_flags = {
69         /* Don't display overruns and proc by default */
70         .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
71                TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS,
72         .opts = trace_opts
73 };
74
75 static struct trace_array *graph_array;
76
77
78 /* Add a function return address to the trace stack on thread info.*/
79 int
80 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
81                          unsigned long frame_pointer)
82 {
83         unsigned long long calltime;
84         int index;
85
86         if (!current->ret_stack)
87                 return -EBUSY;
88
89         /*
90          * We must make sure the ret_stack is tested before we read
91          * anything else.
92          */
93         smp_rmb();
94
95         /* The return trace stack is full */
96         if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
97                 atomic_inc(&current->trace_overrun);
98                 return -EBUSY;
99         }
100
101         calltime = trace_clock_local();
102
103         index = ++current->curr_ret_stack;
104         barrier();
105         current->ret_stack[index].ret = ret;
106         current->ret_stack[index].func = func;
107         current->ret_stack[index].calltime = calltime;
108         current->ret_stack[index].subtime = 0;
109         current->ret_stack[index].fp = frame_pointer;
110         *depth = index;
111
112         return 0;
113 }
114
115 /* Retrieve a function return address to the trace stack on thread info.*/
116 static void
117 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
118                         unsigned long frame_pointer)
119 {
120         int index;
121
122         index = current->curr_ret_stack;
123
124         if (unlikely(index < 0)) {
125                 ftrace_graph_stop();
126                 WARN_ON(1);
127                 /* Might as well panic, otherwise we have no where to go */
128                 *ret = (unsigned long)panic;
129                 return;
130         }
131
132 #ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
133         /*
134          * The arch may choose to record the frame pointer used
135          * and check it here to make sure that it is what we expect it
136          * to be. If gcc does not set the place holder of the return
137          * address in the frame pointer, and does a copy instead, then
138          * the function graph trace will fail. This test detects this
139          * case.
140          *
141          * Currently, x86_32 with optimize for size (-Os) makes the latest
142          * gcc do the above.
143          */
144         if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
145                 ftrace_graph_stop();
146                 WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
147                      "  from func %ps return to %lx\n",
148                      current->ret_stack[index].fp,
149                      frame_pointer,
150                      (void *)current->ret_stack[index].func,
151                      current->ret_stack[index].ret);
152                 *ret = (unsigned long)panic;
153                 return;
154         }
155 #endif
156
157         *ret = current->ret_stack[index].ret;
158         trace->func = current->ret_stack[index].func;
159         trace->calltime = current->ret_stack[index].calltime;
160         trace->overrun = atomic_read(&current->trace_overrun);
161         trace->depth = index;
162 }
163
164 /*
165  * Send the trace to the ring-buffer.
166  * @return the original return address.
167  */
168 unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
169 {
170         struct ftrace_graph_ret trace;
171         unsigned long ret;
172
173         ftrace_pop_return_trace(&trace, &ret, frame_pointer);
174         trace.rettime = trace_clock_local();
175         ftrace_graph_return(&trace);
176         barrier();
177         current->curr_ret_stack--;
178
179         if (unlikely(!ret)) {
180                 ftrace_graph_stop();
181                 WARN_ON(1);
182                 /* Might as well panic. What else to do? */
183                 ret = (unsigned long)panic;
184         }
185
186         return ret;
187 }
188
189 int __trace_graph_entry(struct trace_array *tr,
190                                 struct ftrace_graph_ent *trace,
191                                 unsigned long flags,
192                                 int pc)
193 {
194         struct ftrace_event_call *call = &event_funcgraph_entry;
195         struct ring_buffer_event *event;
196         struct ring_buffer *buffer = tr->buffer;
197         struct ftrace_graph_ent_entry *entry;
198
199         if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
200                 return 0;
201
202         event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
203                                           sizeof(*entry), flags, pc);
204         if (!event)
205                 return 0;
206         entry   = ring_buffer_event_data(event);
207         entry->graph_ent                        = *trace;
208         if (!filter_current_check_discard(buffer, call, entry, event))
209                 ring_buffer_unlock_commit(buffer, event);
210
211         return 1;
212 }
213
214 static inline int ftrace_graph_ignore_irqs(void)
215 {
216         if (!ftrace_graph_skip_irqs)
217                 return 0;
218
219         return in_irq();
220 }
221
222 int trace_graph_entry(struct ftrace_graph_ent *trace)
223 {
224         struct trace_array *tr = graph_array;
225         struct trace_array_cpu *data;
226         unsigned long flags;
227         long disabled;
228         int ret;
229         int cpu;
230         int pc;
231
232         if (!ftrace_trace_task(current))
233                 return 0;
234
235         /* trace it when it is-nested-in or is a function enabled. */
236         if (!(trace->depth || ftrace_graph_addr(trace->func)) ||
237               ftrace_graph_ignore_irqs())
238                 return 0;
239
240         local_irq_save(flags);
241         cpu = raw_smp_processor_id();
242         data = tr->data[cpu];
243         disabled = atomic_inc_return(&data->disabled);
244         if (likely(disabled == 1)) {
245                 pc = preempt_count();
246                 ret = __trace_graph_entry(tr, trace, flags, pc);
247         } else {
248                 ret = 0;
249         }
250
251         atomic_dec(&data->disabled);
252         local_irq_restore(flags);
253
254         return ret;
255 }
256
257 int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
258 {
259         if (tracing_thresh)
260                 return 1;
261         else
262                 return trace_graph_entry(trace);
263 }
264
265 static void
266 __trace_graph_function(struct trace_array *tr,
267                 unsigned long ip, unsigned long flags, int pc)
268 {
269         u64 time = trace_clock_local();
270         struct ftrace_graph_ent ent = {
271                 .func  = ip,
272                 .depth = 0,
273         };
274         struct ftrace_graph_ret ret = {
275                 .func     = ip,
276                 .depth    = 0,
277                 .calltime = time,
278                 .rettime  = time,
279         };
280
281         __trace_graph_entry(tr, &ent, flags, pc);
282         __trace_graph_return(tr, &ret, flags, pc);
283 }
284
285 void
286 trace_graph_function(struct trace_array *tr,
287                 unsigned long ip, unsigned long parent_ip,
288                 unsigned long flags, int pc)
289 {
290         __trace_graph_function(tr, ip, flags, pc);
291 }
292
293 void __trace_graph_return(struct trace_array *tr,
294                                 struct ftrace_graph_ret *trace,
295                                 unsigned long flags,
296                                 int pc)
297 {
298         struct ftrace_event_call *call = &event_funcgraph_exit;
299         struct ring_buffer_event *event;
300         struct ring_buffer *buffer = tr->buffer;
301         struct ftrace_graph_ret_entry *entry;
302
303         if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
304                 return;
305
306         event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
307                                           sizeof(*entry), flags, pc);
308         if (!event)
309                 return;
310         entry   = ring_buffer_event_data(event);
311         entry->ret                              = *trace;
312         if (!filter_current_check_discard(buffer, call, entry, event))
313                 ring_buffer_unlock_commit(buffer, event);
314 }
315
316 void trace_graph_return(struct ftrace_graph_ret *trace)
317 {
318         struct trace_array *tr = graph_array;
319         struct trace_array_cpu *data;
320         unsigned long flags;
321         long disabled;
322         int cpu;
323         int pc;
324
325         local_irq_save(flags);
326         cpu = raw_smp_processor_id();
327         data = tr->data[cpu];
328         disabled = atomic_inc_return(&data->disabled);
329         if (likely(disabled == 1)) {
330                 pc = preempt_count();
331                 __trace_graph_return(tr, trace, flags, pc);
332         }
333         atomic_dec(&data->disabled);
334         local_irq_restore(flags);
335 }
336
337 void set_graph_array(struct trace_array *tr)
338 {
339         graph_array = tr;
340
341         /* Make graph_array visible before we start tracing */
342
343         smp_mb();
344 }
345
346 void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
347 {
348         if (tracing_thresh &&
349             (trace->rettime - trace->calltime < tracing_thresh))
350                 return;
351         else
352                 trace_graph_return(trace);
353 }
354
355 static int graph_trace_init(struct trace_array *tr)
356 {
357         int ret;
358
359         set_graph_array(tr);
360         if (tracing_thresh)
361                 ret = register_ftrace_graph(&trace_graph_thresh_return,
362                                             &trace_graph_thresh_entry);
363         else
364                 ret = register_ftrace_graph(&trace_graph_return,
365                                             &trace_graph_entry);
366         if (ret)
367                 return ret;
368         tracing_start_cmdline_record();
369
370         return 0;
371 }
372
373 static void graph_trace_reset(struct trace_array *tr)
374 {
375         tracing_stop_cmdline_record();
376         unregister_ftrace_graph();
377 }
378
379 static int max_bytes_for_cpu;
380
381 static enum print_line_t
382 print_graph_cpu(struct trace_seq *s, int cpu)
383 {
384         int ret;
385
386         /*
387          * Start with a space character - to make it stand out
388          * to the right a bit when trace output is pasted into
389          * email:
390          */
391         ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
392         if (!ret)
393                 return TRACE_TYPE_PARTIAL_LINE;
394
395         return TRACE_TYPE_HANDLED;
396 }
397
398 #define TRACE_GRAPH_PROCINFO_LENGTH     14
399
400 static enum print_line_t
401 print_graph_proc(struct trace_seq *s, pid_t pid)
402 {
403         char comm[TASK_COMM_LEN];
404         /* sign + log10(MAX_INT) + '\0' */
405         char pid_str[11];
406         int spaces = 0;
407         int ret;
408         int len;
409         int i;
410
411         trace_find_cmdline(pid, comm);
412         comm[7] = '\0';
413         sprintf(pid_str, "%d", pid);
414
415         /* 1 stands for the "-" character */
416         len = strlen(comm) + strlen(pid_str) + 1;
417
418         if (len < TRACE_GRAPH_PROCINFO_LENGTH)
419                 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
420
421         /* First spaces to align center */
422         for (i = 0; i < spaces / 2; i++) {
423                 ret = trace_seq_printf(s, " ");
424                 if (!ret)
425                         return TRACE_TYPE_PARTIAL_LINE;
426         }
427
428         ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
429         if (!ret)
430                 return TRACE_TYPE_PARTIAL_LINE;
431
432         /* Last spaces to align center */
433         for (i = 0; i < spaces - (spaces / 2); i++) {
434                 ret = trace_seq_printf(s, " ");
435                 if (!ret)
436                         return TRACE_TYPE_PARTIAL_LINE;
437         }
438         return TRACE_TYPE_HANDLED;
439 }
440
441
442 static enum print_line_t
443 print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
444 {
445         if (!trace_seq_putc(s, ' '))
446                 return 0;
447
448         return trace_print_lat_fmt(s, entry);
449 }
450
451 /* If the pid changed since the last trace, output this event */
452 static enum print_line_t
453 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
454 {
455         pid_t prev_pid;
456         pid_t *last_pid;
457         int ret;
458
459         if (!data)
460                 return TRACE_TYPE_HANDLED;
461
462         last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
463
464         if (*last_pid == pid)
465                 return TRACE_TYPE_HANDLED;
466
467         prev_pid = *last_pid;
468         *last_pid = pid;
469
470         if (prev_pid == -1)
471                 return TRACE_TYPE_HANDLED;
472 /*
473  * Context-switch trace line:
474
475  ------------------------------------------
476  | 1)  migration/0--1  =>  sshd-1755
477  ------------------------------------------
478
479  */
480         ret = trace_seq_printf(s,
481                 " ------------------------------------------\n");
482         if (!ret)
483                 return TRACE_TYPE_PARTIAL_LINE;
484
485         ret = print_graph_cpu(s, cpu);
486         if (ret == TRACE_TYPE_PARTIAL_LINE)
487                 return TRACE_TYPE_PARTIAL_LINE;
488
489         ret = print_graph_proc(s, prev_pid);
490         if (ret == TRACE_TYPE_PARTIAL_LINE)
491                 return TRACE_TYPE_PARTIAL_LINE;
492
493         ret = trace_seq_printf(s, " => ");
494         if (!ret)
495                 return TRACE_TYPE_PARTIAL_LINE;
496
497         ret = print_graph_proc(s, pid);
498         if (ret == TRACE_TYPE_PARTIAL_LINE)
499                 return TRACE_TYPE_PARTIAL_LINE;
500
501         ret = trace_seq_printf(s,
502                 "\n ------------------------------------------\n\n");
503         if (!ret)
504                 return TRACE_TYPE_PARTIAL_LINE;
505
506         return TRACE_TYPE_HANDLED;
507 }
508
509 static struct ftrace_graph_ret_entry *
510 get_return_for_leaf(struct trace_iterator *iter,
511                 struct ftrace_graph_ent_entry *curr)
512 {
513         struct fgraph_data *data = iter->private;
514         struct ring_buffer_iter *ring_iter = NULL;
515         struct ring_buffer_event *event;
516         struct ftrace_graph_ret_entry *next;
517
518         /*
519          * If the previous output failed to write to the seq buffer,
520          * then we just reuse the data from before.
521          */
522         if (data && data->failed) {
523                 curr = &data->ent;
524                 next = &data->ret;
525         } else {
526
527                 ring_iter = iter->buffer_iter[iter->cpu];
528
529                 /* First peek to compare current entry and the next one */
530                 if (ring_iter)
531                         event = ring_buffer_iter_peek(ring_iter, NULL);
532                 else {
533                         /*
534                          * We need to consume the current entry to see
535                          * the next one.
536                          */
537                         ring_buffer_consume(iter->tr->buffer, iter->cpu,
538                                             NULL, NULL);
539                         event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
540                                                  NULL, NULL);
541                 }
542
543                 if (!event)
544                         return NULL;
545
546                 next = ring_buffer_event_data(event);
547
548                 if (data) {
549                         /*
550                          * Save current and next entries for later reference
551                          * if the output fails.
552                          */
553                         data->ent = *curr;
554                         /*
555                          * If the next event is not a return type, then
556                          * we only care about what type it is. Otherwise we can
557                          * safely copy the entire event.
558                          */
559                         if (next->ent.type == TRACE_GRAPH_RET)
560                                 data->ret = *next;
561                         else
562                                 data->ret.ent.type = next->ent.type;
563                 }
564         }
565
566         if (next->ent.type != TRACE_GRAPH_RET)
567                 return NULL;
568
569         if (curr->ent.pid != next->ent.pid ||
570                         curr->graph_ent.func != next->ret.func)
571                 return NULL;
572
573         /* this is a leaf, now advance the iterator */
574         if (ring_iter)
575                 ring_buffer_read(ring_iter, NULL);
576
577         return next;
578 }
579
580 /* Signal a overhead of time execution to the output */
581 static int
582 print_graph_overhead(unsigned long long duration, struct trace_seq *s,
583                      u32 flags)
584 {
585         /* If duration disappear, we don't need anything */
586         if (!(flags & TRACE_GRAPH_PRINT_DURATION))
587                 return 1;
588
589         /* Non nested entry or return */
590         if (duration == -1)
591                 return trace_seq_printf(s, "  ");
592
593         if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
594                 /* Duration exceeded 100 msecs */
595                 if (duration > 100000ULL)
596                         return trace_seq_printf(s, "! ");
597
598                 /* Duration exceeded 10 msecs */
599                 if (duration > 10000ULL)
600                         return trace_seq_printf(s, "+ ");
601         }
602
603         return trace_seq_printf(s, "  ");
604 }
605
606 static int print_graph_abs_time(u64 t, struct trace_seq *s)
607 {
608         unsigned long usecs_rem;
609
610         usecs_rem = do_div(t, NSEC_PER_SEC);
611         usecs_rem /= 1000;
612
613         return trace_seq_printf(s, "%5lu.%06lu |  ",
614                         (unsigned long)t, usecs_rem);
615 }
616
617 static enum print_line_t
618 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
619                 enum trace_type type, int cpu, pid_t pid, u32 flags)
620 {
621         int ret;
622         struct trace_seq *s = &iter->seq;
623
624         if (addr < (unsigned long)__irqentry_text_start ||
625                 addr >= (unsigned long)__irqentry_text_end)
626                 return TRACE_TYPE_UNHANDLED;
627
628         /* Absolute time */
629         if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
630                 ret = print_graph_abs_time(iter->ts, s);
631                 if (!ret)
632                         return TRACE_TYPE_PARTIAL_LINE;
633         }
634
635         /* Cpu */
636         if (flags & TRACE_GRAPH_PRINT_CPU) {
637                 ret = print_graph_cpu(s, cpu);
638                 if (ret == TRACE_TYPE_PARTIAL_LINE)
639                         return TRACE_TYPE_PARTIAL_LINE;
640         }
641
642         /* Proc */
643         if (flags & TRACE_GRAPH_PRINT_PROC) {
644                 ret = print_graph_proc(s, pid);
645                 if (ret == TRACE_TYPE_PARTIAL_LINE)
646                         return TRACE_TYPE_PARTIAL_LINE;
647                 ret = trace_seq_printf(s, " | ");
648                 if (!ret)
649                         return TRACE_TYPE_PARTIAL_LINE;
650         }
651
652         /* No overhead */
653         ret = print_graph_overhead(-1, s, flags);
654         if (!ret)
655                 return TRACE_TYPE_PARTIAL_LINE;
656
657         if (type == TRACE_GRAPH_ENT)
658                 ret = trace_seq_printf(s, "==========>");
659         else
660                 ret = trace_seq_printf(s, "<==========");
661
662         if (!ret)
663                 return TRACE_TYPE_PARTIAL_LINE;
664
665         /* Don't close the duration column if haven't one */
666         if (flags & TRACE_GRAPH_PRINT_DURATION)
667                 trace_seq_printf(s, " |");
668         ret = trace_seq_printf(s, "\n");
669
670         if (!ret)
671                 return TRACE_TYPE_PARTIAL_LINE;
672         return TRACE_TYPE_HANDLED;
673 }
674
675 enum print_line_t
676 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
677 {
678         unsigned long nsecs_rem = do_div(duration, 1000);
679         /* log10(ULONG_MAX) + '\0' */
680         char msecs_str[21];
681         char nsecs_str[5];
682         int ret, len;
683         int i;
684
685         sprintf(msecs_str, "%lu", (unsigned long) duration);
686
687         /* Print msecs */
688         ret = trace_seq_printf(s, "%s", msecs_str);
689         if (!ret)
690                 return TRACE_TYPE_PARTIAL_LINE;
691
692         len = strlen(msecs_str);
693
694         /* Print nsecs (we don't want to exceed 7 numbers) */
695         if (len < 7) {
696                 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
697
698                 snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
699                 ret = trace_seq_printf(s, ".%s", nsecs_str);
700                 if (!ret)
701                         return TRACE_TYPE_PARTIAL_LINE;
702                 len += strlen(nsecs_str);
703         }
704
705         ret = trace_seq_printf(s, " us ");
706         if (!ret)
707                 return TRACE_TYPE_PARTIAL_LINE;
708
709         /* Print remaining spaces to fit the row's width */
710         for (i = len; i < 7; i++) {
711                 ret = trace_seq_printf(s, " ");
712                 if (!ret)
713                         return TRACE_TYPE_PARTIAL_LINE;
714         }
715         return TRACE_TYPE_HANDLED;
716 }
717
718 static enum print_line_t
719 print_graph_duration(unsigned long long duration, struct trace_seq *s)
720 {
721         int ret;
722
723         ret = trace_print_graph_duration(duration, s);
724         if (ret != TRACE_TYPE_HANDLED)
725                 return ret;
726
727         ret = trace_seq_printf(s, "|  ");
728         if (!ret)
729                 return TRACE_TYPE_PARTIAL_LINE;
730
731         return TRACE_TYPE_HANDLED;
732 }
733
734 /* Case of a leaf function on its call entry */
735 static enum print_line_t
736 print_graph_entry_leaf(struct trace_iterator *iter,
737                 struct ftrace_graph_ent_entry *entry,
738                 struct ftrace_graph_ret_entry *ret_entry,
739                 struct trace_seq *s, u32 flags)
740 {
741         struct fgraph_data *data = iter->private;
742         struct ftrace_graph_ret *graph_ret;
743         struct ftrace_graph_ent *call;
744         unsigned long long duration;
745         int ret;
746         int i;
747
748         graph_ret = &ret_entry->ret;
749         call = &entry->graph_ent;
750         duration = graph_ret->rettime - graph_ret->calltime;
751
752         if (data) {
753                 struct fgraph_cpu_data *cpu_data;
754                 int cpu = iter->cpu;
755
756                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
757
758                 /*
759                  * Comments display at + 1 to depth. Since
760                  * this is a leaf function, keep the comments
761                  * equal to this depth.
762                  */
763                 cpu_data->depth = call->depth - 1;
764
765                 /* No need to keep this function around for this depth */
766                 if (call->depth < FTRACE_RETFUNC_DEPTH)
767                         cpu_data->enter_funcs[call->depth] = 0;
768         }
769
770         /* Overhead */
771         ret = print_graph_overhead(duration, s, flags);
772         if (!ret)
773                 return TRACE_TYPE_PARTIAL_LINE;
774
775         /* Duration */
776         if (flags & TRACE_GRAPH_PRINT_DURATION) {
777                 ret = print_graph_duration(duration, s);
778                 if (ret == TRACE_TYPE_PARTIAL_LINE)
779                         return TRACE_TYPE_PARTIAL_LINE;
780         }
781
782         /* Function */
783         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
784                 ret = trace_seq_printf(s, " ");
785                 if (!ret)
786                         return TRACE_TYPE_PARTIAL_LINE;
787         }
788
789         ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
790         if (!ret)
791                 return TRACE_TYPE_PARTIAL_LINE;
792
793         return TRACE_TYPE_HANDLED;
794 }
795
796 static enum print_line_t
797 print_graph_entry_nested(struct trace_iterator *iter,
798                          struct ftrace_graph_ent_entry *entry,
799                          struct trace_seq *s, int cpu, u32 flags)
800 {
801         struct ftrace_graph_ent *call = &entry->graph_ent;
802         struct fgraph_data *data = iter->private;
803         int ret;
804         int i;
805
806         if (data) {
807                 struct fgraph_cpu_data *cpu_data;
808                 int cpu = iter->cpu;
809
810                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
811                 cpu_data->depth = call->depth;
812
813                 /* Save this function pointer to see if the exit matches */
814                 if (call->depth < FTRACE_RETFUNC_DEPTH)
815                         cpu_data->enter_funcs[call->depth] = call->func;
816         }
817
818         /* No overhead */
819         ret = print_graph_overhead(-1, s, flags);
820         if (!ret)
821                 return TRACE_TYPE_PARTIAL_LINE;
822
823         /* No time */
824         if (flags & TRACE_GRAPH_PRINT_DURATION) {
825                 ret = trace_seq_printf(s, "            |  ");
826                 if (!ret)
827                         return TRACE_TYPE_PARTIAL_LINE;
828         }
829
830         /* Function */
831         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
832                 ret = trace_seq_printf(s, " ");
833                 if (!ret)
834                         return TRACE_TYPE_PARTIAL_LINE;
835         }
836
837         ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
838         if (!ret)
839                 return TRACE_TYPE_PARTIAL_LINE;
840
841         /*
842          * we already consumed the current entry to check the next one
843          * and see if this is a leaf.
844          */
845         return TRACE_TYPE_NO_CONSUME;
846 }
847
848 static enum print_line_t
849 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
850                      int type, unsigned long addr, u32 flags)
851 {
852         struct fgraph_data *data = iter->private;
853         struct trace_entry *ent = iter->ent;
854         int cpu = iter->cpu;
855         int ret;
856
857         /* Pid */
858         if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
859                 return TRACE_TYPE_PARTIAL_LINE;
860
861         if (type) {
862                 /* Interrupt */
863                 ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
864                 if (ret == TRACE_TYPE_PARTIAL_LINE)
865                         return TRACE_TYPE_PARTIAL_LINE;
866         }
867
868         /* Absolute time */
869         if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
870                 ret = print_graph_abs_time(iter->ts, s);
871                 if (!ret)
872                         return TRACE_TYPE_PARTIAL_LINE;
873         }
874
875         /* Cpu */
876         if (flags & TRACE_GRAPH_PRINT_CPU) {
877                 ret = print_graph_cpu(s, cpu);
878                 if (ret == TRACE_TYPE_PARTIAL_LINE)
879                         return TRACE_TYPE_PARTIAL_LINE;
880         }
881
882         /* Proc */
883         if (flags & TRACE_GRAPH_PRINT_PROC) {
884                 ret = print_graph_proc(s, ent->pid);
885                 if (ret == TRACE_TYPE_PARTIAL_LINE)
886                         return TRACE_TYPE_PARTIAL_LINE;
887
888                 ret = trace_seq_printf(s, " | ");
889                 if (!ret)
890                         return TRACE_TYPE_PARTIAL_LINE;
891         }
892
893         /* Latency format */
894         if (trace_flags & TRACE_ITER_LATENCY_FMT) {
895                 ret = print_graph_lat_fmt(s, ent);
896                 if (ret == TRACE_TYPE_PARTIAL_LINE)
897                         return TRACE_TYPE_PARTIAL_LINE;
898         }
899
900         return 0;
901 }
902
903 /*
904  * Entry check for irq code
905  *
906  * returns 1 if
907  *  - we are inside irq code
908  *  - we just extered irq code
909  *
910  * retunns 0 if
911  *  - funcgraph-interrupts option is set
912  *  - we are not inside irq code
913  */
914 static int
915 check_irq_entry(struct trace_iterator *iter, u32 flags,
916                 unsigned long addr, int depth)
917 {
918         int cpu = iter->cpu;
919         int *depth_irq;
920         struct fgraph_data *data = iter->private;
921
922         /*
923          * If we are either displaying irqs, or we got called as
924          * a graph event and private data does not exist,
925          * then we bypass the irq check.
926          */
927         if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
928             (!data))
929                 return 0;
930
931         depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
932
933         /*
934          * We are inside the irq code
935          */
936         if (*depth_irq >= 0)
937                 return 1;
938
939         if ((addr < (unsigned long)__irqentry_text_start) ||
940             (addr >= (unsigned long)__irqentry_text_end))
941                 return 0;
942
943         /*
944          * We are entering irq code.
945          */
946         *depth_irq = depth;
947         return 1;
948 }
949
950 /*
951  * Return check for irq code
952  *
953  * returns 1 if
954  *  - we are inside irq code
955  *  - we just left irq code
956  *
957  * returns 0 if
958  *  - funcgraph-interrupts option is set
959  *  - we are not inside irq code
960  */
961 static int
962 check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
963 {
964         int cpu = iter->cpu;
965         int *depth_irq;
966         struct fgraph_data *data = iter->private;
967
968         /*
969          * If we are either displaying irqs, or we got called as
970          * a graph event and private data does not exist,
971          * then we bypass the irq check.
972          */
973         if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
974             (!data))
975                 return 0;
976
977         depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
978
979         /*
980          * We are not inside the irq code.
981          */
982         if (*depth_irq == -1)
983                 return 0;
984
985         /*
986          * We are inside the irq code, and this is returning entry.
987          * Let's not trace it and clear the entry depth, since
988          * we are out of irq code.
989          *
990          * This condition ensures that we 'leave the irq code' once
991          * we are out of the entry depth. Thus protecting us from
992          * the RETURN entry loss.
993          */
994         if (*depth_irq >= depth) {
995                 *depth_irq = -1;
996                 return 1;
997         }
998
999         /*
1000          * We are inside the irq code, and this is not the entry.
1001          */
1002         return 1;
1003 }
1004
1005 static enum print_line_t
1006 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
1007                         struct trace_iterator *iter, u32 flags)
1008 {
1009         struct fgraph_data *data = iter->private;
1010         struct ftrace_graph_ent *call = &field->graph_ent;
1011         struct ftrace_graph_ret_entry *leaf_ret;
1012         static enum print_line_t ret;
1013         int cpu = iter->cpu;
1014
1015         if (check_irq_entry(iter, flags, call->func, call->depth))
1016                 return TRACE_TYPE_HANDLED;
1017
1018         if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
1019                 return TRACE_TYPE_PARTIAL_LINE;
1020
1021         leaf_ret = get_return_for_leaf(iter, field);
1022         if (leaf_ret)
1023                 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
1024         else
1025                 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
1026
1027         if (data) {
1028                 /*
1029                  * If we failed to write our output, then we need to make
1030                  * note of it. Because we already consumed our entry.
1031                  */
1032                 if (s->full) {
1033                         data->failed = 1;
1034                         data->cpu = cpu;
1035                 } else
1036                         data->failed = 0;
1037         }
1038
1039         return ret;
1040 }
1041
1042 static enum print_line_t
1043 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
1044                    struct trace_entry *ent, struct trace_iterator *iter,
1045                    u32 flags)
1046 {
1047         unsigned long long duration = trace->rettime - trace->calltime;
1048         struct fgraph_data *data = iter->private;
1049         pid_t pid = ent->pid;
1050         int cpu = iter->cpu;
1051         int func_match = 1;
1052         int ret;
1053         int i;
1054
1055         if (check_irq_return(iter, flags, trace->depth))
1056                 return TRACE_TYPE_HANDLED;
1057
1058         if (data) {
1059                 struct fgraph_cpu_data *cpu_data;
1060                 int cpu = iter->cpu;
1061
1062                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1063
1064                 /*
1065                  * Comments display at + 1 to depth. This is the
1066                  * return from a function, we now want the comments
1067                  * to display at the same level of the bracket.
1068                  */
1069                 cpu_data->depth = trace->depth - 1;
1070
1071                 if (trace->depth < FTRACE_RETFUNC_DEPTH) {
1072                         if (cpu_data->enter_funcs[trace->depth] != trace->func)
1073                                 func_match = 0;
1074                         cpu_data->enter_funcs[trace->depth] = 0;
1075                 }
1076         }
1077
1078         if (print_graph_prologue(iter, s, 0, 0, flags))
1079                 return TRACE_TYPE_PARTIAL_LINE;
1080
1081         /* Overhead */
1082         ret = print_graph_overhead(duration, s, flags);
1083         if (!ret)
1084                 return TRACE_TYPE_PARTIAL_LINE;
1085
1086         /* Duration */
1087         if (flags & TRACE_GRAPH_PRINT_DURATION) {
1088                 ret = print_graph_duration(duration, s);
1089                 if (ret == TRACE_TYPE_PARTIAL_LINE)
1090                         return TRACE_TYPE_PARTIAL_LINE;
1091         }
1092
1093         /* Closing brace */
1094         for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
1095                 ret = trace_seq_printf(s, " ");
1096                 if (!ret)
1097                         return TRACE_TYPE_PARTIAL_LINE;
1098         }
1099
1100         /*
1101          * If the return function does not have a matching entry,
1102          * then the entry was lost. Instead of just printing
1103          * the '}' and letting the user guess what function this
1104          * belongs to, write out the function name.
1105          */
1106         if (func_match) {
1107                 ret = trace_seq_printf(s, "}\n");
1108                 if (!ret)
1109                         return TRACE_TYPE_PARTIAL_LINE;
1110         } else {
1111                 ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
1112                 if (!ret)
1113                         return TRACE_TYPE_PARTIAL_LINE;
1114         }
1115
1116         /* Overrun */
1117         if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
1118                 ret = trace_seq_printf(s, " (Overruns: %lu)\n",
1119                                         trace->overrun);
1120                 if (!ret)
1121                         return TRACE_TYPE_PARTIAL_LINE;
1122         }
1123
1124         ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
1125                               cpu, pid, flags);
1126         if (ret == TRACE_TYPE_PARTIAL_LINE)
1127                 return TRACE_TYPE_PARTIAL_LINE;
1128
1129         return TRACE_TYPE_HANDLED;
1130 }
1131
1132 static enum print_line_t
1133 print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
1134                     struct trace_iterator *iter, u32 flags)
1135 {
1136         unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1137         struct fgraph_data *data = iter->private;
1138         struct trace_event *event;
1139         int depth = 0;
1140         int ret;
1141         int i;
1142
1143         if (data)
1144                 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
1145
1146         if (print_graph_prologue(iter, s, 0, 0, flags))
1147                 return TRACE_TYPE_PARTIAL_LINE;
1148
1149         /* No overhead */
1150         ret = print_graph_overhead(-1, s, flags);
1151         if (!ret)
1152                 return TRACE_TYPE_PARTIAL_LINE;
1153
1154         /* No time */
1155         if (flags & TRACE_GRAPH_PRINT_DURATION) {
1156                 ret = trace_seq_printf(s, "            |  ");
1157                 if (!ret)
1158                         return TRACE_TYPE_PARTIAL_LINE;
1159         }
1160
1161         /* Indentation */
1162         if (depth > 0)
1163                 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
1164                         ret = trace_seq_printf(s, " ");
1165                         if (!ret)
1166                                 return TRACE_TYPE_PARTIAL_LINE;
1167                 }
1168
1169         /* The comment */
1170         ret = trace_seq_printf(s, "/* ");
1171         if (!ret)
1172                 return TRACE_TYPE_PARTIAL_LINE;
1173
1174         switch (iter->ent->type) {
1175         case TRACE_BPRINT:
1176                 ret = trace_print_bprintk_msg_only(iter);
1177                 if (ret != TRACE_TYPE_HANDLED)
1178                         return ret;
1179                 break;
1180         case TRACE_PRINT:
1181                 ret = trace_print_printk_msg_only(iter);
1182                 if (ret != TRACE_TYPE_HANDLED)
1183                         return ret;
1184                 break;
1185         default:
1186                 event = ftrace_find_event(ent->type);
1187                 if (!event)
1188                         return TRACE_TYPE_UNHANDLED;
1189
1190                 ret = event->funcs->trace(iter, sym_flags, event);
1191                 if (ret != TRACE_TYPE_HANDLED)
1192                         return ret;
1193         }
1194
1195         /* Strip ending newline */
1196         if (s->buffer[s->len - 1] == '\n') {
1197                 s->buffer[s->len - 1] = '\0';
1198                 s->len--;
1199         }
1200
1201         ret = trace_seq_printf(s, " */\n");
1202         if (!ret)
1203                 return TRACE_TYPE_PARTIAL_LINE;
1204
1205         return TRACE_TYPE_HANDLED;
1206 }
1207
1208
1209 enum print_line_t
1210 __print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1211 {
1212         struct ftrace_graph_ent_entry *field;
1213         struct fgraph_data *data = iter->private;
1214         struct trace_entry *entry = iter->ent;
1215         struct trace_seq *s = &iter->seq;
1216         int cpu = iter->cpu;
1217         int ret;
1218
1219         if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1220                 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1221                 return TRACE_TYPE_HANDLED;
1222         }
1223
1224         /*
1225          * If the last output failed, there's a possibility we need
1226          * to print out the missing entry which would never go out.
1227          */
1228         if (data && data->failed) {
1229                 field = &data->ent;
1230                 iter->cpu = data->cpu;
1231                 ret = print_graph_entry(field, s, iter, flags);
1232                 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1233                         per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1234                         ret = TRACE_TYPE_NO_CONSUME;
1235                 }
1236                 iter->cpu = cpu;
1237                 return ret;
1238         }
1239
1240         switch (entry->type) {
1241         case TRACE_GRAPH_ENT: {
1242                 /*
1243                  * print_graph_entry() may consume the current event,
1244                  * thus @field may become invalid, so we need to save it.
1245                  * sizeof(struct ftrace_graph_ent_entry) is very small,
1246                  * it can be safely saved at the stack.
1247                  */
1248                 struct ftrace_graph_ent_entry saved;
1249                 trace_assign_type(field, entry);
1250                 saved = *field;
1251                 return print_graph_entry(&saved, s, iter, flags);
1252         }
1253         case TRACE_GRAPH_RET: {
1254                 struct ftrace_graph_ret_entry *field;
1255                 trace_assign_type(field, entry);
1256                 return print_graph_return(&field->ret, s, entry, iter, flags);
1257         }
1258         case TRACE_STACK:
1259         case TRACE_FN:
1260                 /* dont trace stack and functions as comments */
1261                 return TRACE_TYPE_UNHANDLED;
1262
1263         default:
1264                 return print_graph_comment(s, entry, iter, flags);
1265         }
1266
1267         return TRACE_TYPE_HANDLED;
1268 }
1269
1270 static enum print_line_t
1271 print_graph_function(struct trace_iterator *iter)
1272 {
1273         return __print_graph_function_flags(iter, tracer_flags.val);
1274 }
1275
1276 enum print_line_t print_graph_function_flags(struct trace_iterator *iter,
1277                                              u32 flags)
1278 {
1279         if (trace_flags & TRACE_ITER_LATENCY_FMT)
1280                 flags |= TRACE_GRAPH_PRINT_DURATION;
1281         else
1282                 flags |= TRACE_GRAPH_PRINT_ABS_TIME;
1283
1284         return __print_graph_function_flags(iter, flags);
1285 }
1286
1287 static enum print_line_t
1288 print_graph_function_event(struct trace_iterator *iter, int flags,
1289                            struct trace_event *event)
1290 {
1291         return print_graph_function(iter);
1292 }
1293
1294 static void print_lat_header(struct seq_file *s, u32 flags)
1295 {
1296         static const char spaces[] = "                " /* 16 spaces */
1297                 "    "                                  /* 4 spaces */
1298                 "                 ";                    /* 17 spaces */
1299         int size = 0;
1300
1301         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1302                 size += 16;
1303         if (flags & TRACE_GRAPH_PRINT_CPU)
1304                 size += 4;
1305         if (flags & TRACE_GRAPH_PRINT_PROC)
1306                 size += 17;
1307
1308         seq_printf(s, "#%.*s  _-----=> irqs-off        \n", size, spaces);
1309         seq_printf(s, "#%.*s / _----=> need-resched    \n", size, spaces);
1310         seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1311         seq_printf(s, "#%.*s|| / _--=> preempt-depth   \n", size, spaces);
1312         seq_printf(s, "#%.*s||| / _-=> lock-depth      \n", size, spaces);
1313         seq_printf(s, "#%.*s|||| /                     \n", size, spaces);
1314 }
1315
1316 static void __print_graph_headers_flags(struct seq_file *s, u32 flags)
1317 {
1318         int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
1319
1320         if (lat)
1321                 print_lat_header(s, flags);
1322
1323         /* 1st line */
1324         seq_printf(s, "#");
1325         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1326                 seq_printf(s, "     TIME       ");
1327         if (flags & TRACE_GRAPH_PRINT_CPU)
1328                 seq_printf(s, " CPU");
1329         if (flags & TRACE_GRAPH_PRINT_PROC)
1330                 seq_printf(s, "  TASK/PID       ");
1331         if (lat)
1332                 seq_printf(s, "|||||");
1333         if (flags & TRACE_GRAPH_PRINT_DURATION)
1334                 seq_printf(s, "  DURATION   ");
1335         seq_printf(s, "               FUNCTION CALLS\n");
1336
1337         /* 2nd line */
1338         seq_printf(s, "#");
1339         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1340                 seq_printf(s, "      |         ");
1341         if (flags & TRACE_GRAPH_PRINT_CPU)
1342                 seq_printf(s, " |  ");
1343         if (flags & TRACE_GRAPH_PRINT_PROC)
1344                 seq_printf(s, "   |    |        ");
1345         if (lat)
1346                 seq_printf(s, "|||||");
1347         if (flags & TRACE_GRAPH_PRINT_DURATION)
1348                 seq_printf(s, "   |   |      ");
1349         seq_printf(s, "               |   |   |   |\n");
1350 }
1351
1352 void print_graph_headers(struct seq_file *s)
1353 {
1354         print_graph_headers_flags(s, tracer_flags.val);
1355 }
1356
1357 void print_graph_headers_flags(struct seq_file *s, u32 flags)
1358 {
1359         struct trace_iterator *iter = s->private;
1360
1361         if (trace_flags & TRACE_ITER_LATENCY_FMT) {
1362                 /* print nothing if the buffers are empty */
1363                 if (trace_empty(iter))
1364                         return;
1365
1366                 print_trace_header(s, iter);
1367                 flags |= TRACE_GRAPH_PRINT_DURATION;
1368         } else
1369                 flags |= TRACE_GRAPH_PRINT_ABS_TIME;
1370
1371         __print_graph_headers_flags(s, flags);
1372 }
1373
1374 void graph_trace_open(struct trace_iterator *iter)
1375 {
1376         /* pid and depth on the last trace processed */
1377         struct fgraph_data *data;
1378         int cpu;
1379
1380         iter->private = NULL;
1381
1382         data = kzalloc(sizeof(*data), GFP_KERNEL);
1383         if (!data)
1384                 goto out_err;
1385
1386         data->cpu_data = alloc_percpu(struct fgraph_cpu_data);
1387         if (!data->cpu_data)
1388                 goto out_err_free;
1389
1390         for_each_possible_cpu(cpu) {
1391                 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1392                 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1393                 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1394                 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1395
1396                 *pid = -1;
1397                 *depth = 0;
1398                 *ignore = 0;
1399                 *depth_irq = -1;
1400         }
1401
1402         iter->private = data;
1403
1404         return;
1405
1406  out_err_free:
1407         kfree(data);
1408  out_err:
1409         pr_warning("function graph tracer: not enough memory\n");
1410 }
1411
1412 void graph_trace_close(struct trace_iterator *iter)
1413 {
1414         struct fgraph_data *data = iter->private;
1415
1416         if (data) {
1417                 free_percpu(data->cpu_data);
1418                 kfree(data);
1419         }
1420 }
1421
1422 static int func_graph_set_flag(u32 old_flags, u32 bit, int set)
1423 {
1424         if (bit == TRACE_GRAPH_PRINT_IRQS)
1425                 ftrace_graph_skip_irqs = !set;
1426
1427         return 0;
1428 }
1429
1430 static struct trace_event_functions graph_functions = {
1431         .trace          = print_graph_function_event,
1432 };
1433
1434 static struct trace_event graph_trace_entry_event = {
1435         .type           = TRACE_GRAPH_ENT,
1436         .funcs          = &graph_functions,
1437 };
1438
1439 static struct trace_event graph_trace_ret_event = {
1440         .type           = TRACE_GRAPH_RET,
1441         .funcs          = &graph_functions
1442 };
1443
1444 static struct tracer graph_trace __read_mostly = {
1445         .name           = "function_graph",
1446         .open           = graph_trace_open,
1447         .pipe_open      = graph_trace_open,
1448         .close          = graph_trace_close,
1449         .pipe_close     = graph_trace_close,
1450         .wait_pipe      = poll_wait_pipe,
1451         .init           = graph_trace_init,
1452         .reset          = graph_trace_reset,
1453         .print_line     = print_graph_function,
1454         .print_header   = print_graph_headers,
1455         .flags          = &tracer_flags,
1456         .set_flag       = func_graph_set_flag,
1457 #ifdef CONFIG_FTRACE_SELFTEST
1458         .selftest       = trace_selftest_startup_function_graph,
1459 #endif
1460 };
1461
1462 static __init int init_graph_trace(void)
1463 {
1464         max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
1465
1466         if (!register_ftrace_event(&graph_trace_entry_event)) {
1467                 pr_warning("Warning: could not register graph trace events\n");
1468                 return 1;
1469         }
1470
1471         if (!register_ftrace_event(&graph_trace_ret_event)) {
1472                 pr_warning("Warning: could not register graph trace events\n");
1473                 return 1;
1474         }
1475
1476         return register_tracer(&graph_trace);
1477 }
1478
1479 device_initcall(init_graph_trace);