tracing: Allow tracers to start at core initcall
[linux-3.10.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  * DURATION column is being also used to display IRQ signs,
79  * following values are used by print_graph_irq and others
80  * to fill in space into DURATION column.
81  */
82 enum {
83         DURATION_FILL_FULL  = -1,
84         DURATION_FILL_START = -2,
85         DURATION_FILL_END   = -3,
86 };
87
88 static enum print_line_t
89 print_graph_duration(unsigned long long duration, struct trace_seq *s,
90                      u32 flags);
91
92 /* Add a function return address to the trace stack on thread info.*/
93 int
94 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
95                          unsigned long frame_pointer)
96 {
97         unsigned long long calltime;
98         int index;
99
100         if (!current->ret_stack)
101                 return -EBUSY;
102
103         /*
104          * We must make sure the ret_stack is tested before we read
105          * anything else.
106          */
107         smp_rmb();
108
109         /* The return trace stack is full */
110         if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
111                 atomic_inc(&current->trace_overrun);
112                 return -EBUSY;
113         }
114
115         calltime = trace_clock_local();
116
117         index = ++current->curr_ret_stack;
118         barrier();
119         current->ret_stack[index].ret = ret;
120         current->ret_stack[index].func = func;
121         current->ret_stack[index].calltime = calltime;
122         current->ret_stack[index].subtime = 0;
123         current->ret_stack[index].fp = frame_pointer;
124         *depth = index;
125
126         return 0;
127 }
128
129 /* Retrieve a function return address to the trace stack on thread info.*/
130 static void
131 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
132                         unsigned long frame_pointer)
133 {
134         int index;
135
136         index = current->curr_ret_stack;
137
138         if (unlikely(index < 0)) {
139                 ftrace_graph_stop();
140                 WARN_ON(1);
141                 /* Might as well panic, otherwise we have no where to go */
142                 *ret = (unsigned long)panic;
143                 return;
144         }
145
146 #if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY)
147         /*
148          * The arch may choose to record the frame pointer used
149          * and check it here to make sure that it is what we expect it
150          * to be. If gcc does not set the place holder of the return
151          * address in the frame pointer, and does a copy instead, then
152          * the function graph trace will fail. This test detects this
153          * case.
154          *
155          * Currently, x86_32 with optimize for size (-Os) makes the latest
156          * gcc do the above.
157          *
158          * Note, -mfentry does not use frame pointers, and this test
159          *  is not needed if CC_USING_FENTRY is set.
160          */
161         if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
162                 ftrace_graph_stop();
163                 WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
164                      "  from func %ps return to %lx\n",
165                      current->ret_stack[index].fp,
166                      frame_pointer,
167                      (void *)current->ret_stack[index].func,
168                      current->ret_stack[index].ret);
169                 *ret = (unsigned long)panic;
170                 return;
171         }
172 #endif
173
174         *ret = current->ret_stack[index].ret;
175         trace->func = current->ret_stack[index].func;
176         trace->calltime = current->ret_stack[index].calltime;
177         trace->overrun = atomic_read(&current->trace_overrun);
178         trace->depth = index;
179 }
180
181 /*
182  * Send the trace to the ring-buffer.
183  * @return the original return address.
184  */
185 unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
186 {
187         struct ftrace_graph_ret trace;
188         unsigned long ret;
189
190         ftrace_pop_return_trace(&trace, &ret, frame_pointer);
191         trace.rettime = trace_clock_local();
192         ftrace_graph_return(&trace);
193         barrier();
194         current->curr_ret_stack--;
195
196         if (unlikely(!ret)) {
197                 ftrace_graph_stop();
198                 WARN_ON(1);
199                 /* Might as well panic. What else to do? */
200                 ret = (unsigned long)panic;
201         }
202
203         return ret;
204 }
205
206 int __trace_graph_entry(struct trace_array *tr,
207                                 struct ftrace_graph_ent *trace,
208                                 unsigned long flags,
209                                 int pc)
210 {
211         struct ftrace_event_call *call = &event_funcgraph_entry;
212         struct ring_buffer_event *event;
213         struct ring_buffer *buffer = tr->buffer;
214         struct ftrace_graph_ent_entry *entry;
215
216         if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
217                 return 0;
218
219         event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
220                                           sizeof(*entry), flags, pc);
221         if (!event)
222                 return 0;
223         entry   = ring_buffer_event_data(event);
224         entry->graph_ent                        = *trace;
225         if (!filter_current_check_discard(buffer, call, entry, event))
226                 ring_buffer_unlock_commit(buffer, event);
227
228         return 1;
229 }
230
231 static inline int ftrace_graph_ignore_irqs(void)
232 {
233         if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
234                 return 0;
235
236         return in_irq();
237 }
238
239 int trace_graph_entry(struct ftrace_graph_ent *trace)
240 {
241         struct trace_array *tr = graph_array;
242         struct trace_array_cpu *data;
243         unsigned long flags;
244         long disabled;
245         int ret;
246         int cpu;
247         int pc;
248
249         if (!ftrace_trace_task(current))
250                 return 0;
251
252         /* trace it when it is-nested-in or is a function enabled. */
253         if (!(trace->depth || ftrace_graph_addr(trace->func)) ||
254               ftrace_graph_ignore_irqs())
255                 return 0;
256
257         local_irq_save(flags);
258         cpu = raw_smp_processor_id();
259         data = tr->data[cpu];
260         disabled = atomic_inc_return(&data->disabled);
261         if (likely(disabled == 1)) {
262                 pc = preempt_count();
263                 ret = __trace_graph_entry(tr, trace, flags, pc);
264         } else {
265                 ret = 0;
266         }
267
268         atomic_dec(&data->disabled);
269         local_irq_restore(flags);
270
271         return ret;
272 }
273
274 int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
275 {
276         if (tracing_thresh)
277                 return 1;
278         else
279                 return trace_graph_entry(trace);
280 }
281
282 static void
283 __trace_graph_function(struct trace_array *tr,
284                 unsigned long ip, unsigned long flags, int pc)
285 {
286         u64 time = trace_clock_local();
287         struct ftrace_graph_ent ent = {
288                 .func  = ip,
289                 .depth = 0,
290         };
291         struct ftrace_graph_ret ret = {
292                 .func     = ip,
293                 .depth    = 0,
294                 .calltime = time,
295                 .rettime  = time,
296         };
297
298         __trace_graph_entry(tr, &ent, flags, pc);
299         __trace_graph_return(tr, &ret, flags, pc);
300 }
301
302 void
303 trace_graph_function(struct trace_array *tr,
304                 unsigned long ip, unsigned long parent_ip,
305                 unsigned long flags, int pc)
306 {
307         __trace_graph_function(tr, ip, flags, pc);
308 }
309
310 void __trace_graph_return(struct trace_array *tr,
311                                 struct ftrace_graph_ret *trace,
312                                 unsigned long flags,
313                                 int pc)
314 {
315         struct ftrace_event_call *call = &event_funcgraph_exit;
316         struct ring_buffer_event *event;
317         struct ring_buffer *buffer = tr->buffer;
318         struct ftrace_graph_ret_entry *entry;
319
320         if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
321                 return;
322
323         event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
324                                           sizeof(*entry), flags, pc);
325         if (!event)
326                 return;
327         entry   = ring_buffer_event_data(event);
328         entry->ret                              = *trace;
329         if (!filter_current_check_discard(buffer, call, entry, event))
330                 ring_buffer_unlock_commit(buffer, event);
331 }
332
333 void trace_graph_return(struct ftrace_graph_ret *trace)
334 {
335         struct trace_array *tr = graph_array;
336         struct trace_array_cpu *data;
337         unsigned long flags;
338         long disabled;
339         int cpu;
340         int pc;
341
342         local_irq_save(flags);
343         cpu = raw_smp_processor_id();
344         data = tr->data[cpu];
345         disabled = atomic_inc_return(&data->disabled);
346         if (likely(disabled == 1)) {
347                 pc = preempt_count();
348                 __trace_graph_return(tr, trace, flags, pc);
349         }
350         atomic_dec(&data->disabled);
351         local_irq_restore(flags);
352 }
353
354 void set_graph_array(struct trace_array *tr)
355 {
356         graph_array = tr;
357
358         /* Make graph_array visible before we start tracing */
359
360         smp_mb();
361 }
362
363 void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
364 {
365         if (tracing_thresh &&
366             (trace->rettime - trace->calltime < tracing_thresh))
367                 return;
368         else
369                 trace_graph_return(trace);
370 }
371
372 static int graph_trace_init(struct trace_array *tr)
373 {
374         int ret;
375
376         set_graph_array(tr);
377         if (tracing_thresh)
378                 ret = register_ftrace_graph(&trace_graph_thresh_return,
379                                             &trace_graph_thresh_entry);
380         else
381                 ret = register_ftrace_graph(&trace_graph_return,
382                                             &trace_graph_entry);
383         if (ret)
384                 return ret;
385         tracing_start_cmdline_record();
386
387         return 0;
388 }
389
390 static void graph_trace_reset(struct trace_array *tr)
391 {
392         tracing_stop_cmdline_record();
393         unregister_ftrace_graph();
394 }
395
396 static int max_bytes_for_cpu;
397
398 static enum print_line_t
399 print_graph_cpu(struct trace_seq *s, int cpu)
400 {
401         int ret;
402
403         /*
404          * Start with a space character - to make it stand out
405          * to the right a bit when trace output is pasted into
406          * email:
407          */
408         ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
409         if (!ret)
410                 return TRACE_TYPE_PARTIAL_LINE;
411
412         return TRACE_TYPE_HANDLED;
413 }
414
415 #define TRACE_GRAPH_PROCINFO_LENGTH     14
416
417 static enum print_line_t
418 print_graph_proc(struct trace_seq *s, pid_t pid)
419 {
420         char comm[TASK_COMM_LEN];
421         /* sign + log10(MAX_INT) + '\0' */
422         char pid_str[11];
423         int spaces = 0;
424         int ret;
425         int len;
426         int i;
427
428         trace_find_cmdline(pid, comm);
429         comm[7] = '\0';
430         sprintf(pid_str, "%d", pid);
431
432         /* 1 stands for the "-" character */
433         len = strlen(comm) + strlen(pid_str) + 1;
434
435         if (len < TRACE_GRAPH_PROCINFO_LENGTH)
436                 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
437
438         /* First spaces to align center */
439         for (i = 0; i < spaces / 2; i++) {
440                 ret = trace_seq_printf(s, " ");
441                 if (!ret)
442                         return TRACE_TYPE_PARTIAL_LINE;
443         }
444
445         ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
446         if (!ret)
447                 return TRACE_TYPE_PARTIAL_LINE;
448
449         /* Last spaces to align center */
450         for (i = 0; i < spaces - (spaces / 2); i++) {
451                 ret = trace_seq_printf(s, " ");
452                 if (!ret)
453                         return TRACE_TYPE_PARTIAL_LINE;
454         }
455         return TRACE_TYPE_HANDLED;
456 }
457
458
459 static enum print_line_t
460 print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
461 {
462         if (!trace_seq_putc(s, ' '))
463                 return 0;
464
465         return trace_print_lat_fmt(s, entry);
466 }
467
468 /* If the pid changed since the last trace, output this event */
469 static enum print_line_t
470 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
471 {
472         pid_t prev_pid;
473         pid_t *last_pid;
474         int ret;
475
476         if (!data)
477                 return TRACE_TYPE_HANDLED;
478
479         last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
480
481         if (*last_pid == pid)
482                 return TRACE_TYPE_HANDLED;
483
484         prev_pid = *last_pid;
485         *last_pid = pid;
486
487         if (prev_pid == -1)
488                 return TRACE_TYPE_HANDLED;
489 /*
490  * Context-switch trace line:
491
492  ------------------------------------------
493  | 1)  migration/0--1  =>  sshd-1755
494  ------------------------------------------
495
496  */
497         ret = trace_seq_printf(s,
498                 " ------------------------------------------\n");
499         if (!ret)
500                 return TRACE_TYPE_PARTIAL_LINE;
501
502         ret = print_graph_cpu(s, cpu);
503         if (ret == TRACE_TYPE_PARTIAL_LINE)
504                 return TRACE_TYPE_PARTIAL_LINE;
505
506         ret = print_graph_proc(s, prev_pid);
507         if (ret == TRACE_TYPE_PARTIAL_LINE)
508                 return TRACE_TYPE_PARTIAL_LINE;
509
510         ret = trace_seq_printf(s, " => ");
511         if (!ret)
512                 return TRACE_TYPE_PARTIAL_LINE;
513
514         ret = print_graph_proc(s, pid);
515         if (ret == TRACE_TYPE_PARTIAL_LINE)
516                 return TRACE_TYPE_PARTIAL_LINE;
517
518         ret = trace_seq_printf(s,
519                 "\n ------------------------------------------\n\n");
520         if (!ret)
521                 return TRACE_TYPE_PARTIAL_LINE;
522
523         return TRACE_TYPE_HANDLED;
524 }
525
526 static struct ftrace_graph_ret_entry *
527 get_return_for_leaf(struct trace_iterator *iter,
528                 struct ftrace_graph_ent_entry *curr)
529 {
530         struct fgraph_data *data = iter->private;
531         struct ring_buffer_iter *ring_iter = NULL;
532         struct ring_buffer_event *event;
533         struct ftrace_graph_ret_entry *next;
534
535         /*
536          * If the previous output failed to write to the seq buffer,
537          * then we just reuse the data from before.
538          */
539         if (data && data->failed) {
540                 curr = &data->ent;
541                 next = &data->ret;
542         } else {
543
544                 ring_iter = trace_buffer_iter(iter, iter->cpu);
545
546                 /* First peek to compare current entry and the next one */
547                 if (ring_iter)
548                         event = ring_buffer_iter_peek(ring_iter, NULL);
549                 else {
550                         /*
551                          * We need to consume the current entry to see
552                          * the next one.
553                          */
554                         ring_buffer_consume(iter->tr->buffer, iter->cpu,
555                                             NULL, NULL);
556                         event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
557                                                  NULL, NULL);
558                 }
559
560                 if (!event)
561                         return NULL;
562
563                 next = ring_buffer_event_data(event);
564
565                 if (data) {
566                         /*
567                          * Save current and next entries for later reference
568                          * if the output fails.
569                          */
570                         data->ent = *curr;
571                         /*
572                          * If the next event is not a return type, then
573                          * we only care about what type it is. Otherwise we can
574                          * safely copy the entire event.
575                          */
576                         if (next->ent.type == TRACE_GRAPH_RET)
577                                 data->ret = *next;
578                         else
579                                 data->ret.ent.type = next->ent.type;
580                 }
581         }
582
583         if (next->ent.type != TRACE_GRAPH_RET)
584                 return NULL;
585
586         if (curr->ent.pid != next->ent.pid ||
587                         curr->graph_ent.func != next->ret.func)
588                 return NULL;
589
590         /* this is a leaf, now advance the iterator */
591         if (ring_iter)
592                 ring_buffer_read(ring_iter, NULL);
593
594         return next;
595 }
596
597 static int print_graph_abs_time(u64 t, struct trace_seq *s)
598 {
599         unsigned long usecs_rem;
600
601         usecs_rem = do_div(t, NSEC_PER_SEC);
602         usecs_rem /= 1000;
603
604         return trace_seq_printf(s, "%5lu.%06lu |  ",
605                         (unsigned long)t, usecs_rem);
606 }
607
608 static enum print_line_t
609 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
610                 enum trace_type type, int cpu, pid_t pid, u32 flags)
611 {
612         int ret;
613         struct trace_seq *s = &iter->seq;
614
615         if (addr < (unsigned long)__irqentry_text_start ||
616                 addr >= (unsigned long)__irqentry_text_end)
617                 return TRACE_TYPE_UNHANDLED;
618
619         if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
620                 /* Absolute time */
621                 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
622                         ret = print_graph_abs_time(iter->ts, s);
623                         if (!ret)
624                                 return TRACE_TYPE_PARTIAL_LINE;
625                 }
626
627                 /* Cpu */
628                 if (flags & TRACE_GRAPH_PRINT_CPU) {
629                         ret = print_graph_cpu(s, cpu);
630                         if (ret == TRACE_TYPE_PARTIAL_LINE)
631                                 return TRACE_TYPE_PARTIAL_LINE;
632                 }
633
634                 /* Proc */
635                 if (flags & TRACE_GRAPH_PRINT_PROC) {
636                         ret = print_graph_proc(s, pid);
637                         if (ret == TRACE_TYPE_PARTIAL_LINE)
638                                 return TRACE_TYPE_PARTIAL_LINE;
639                         ret = trace_seq_printf(s, " | ");
640                         if (!ret)
641                                 return TRACE_TYPE_PARTIAL_LINE;
642                 }
643         }
644
645         /* No overhead */
646         ret = print_graph_duration(DURATION_FILL_START, s, flags);
647         if (ret != TRACE_TYPE_HANDLED)
648                 return ret;
649
650         if (type == TRACE_GRAPH_ENT)
651                 ret = trace_seq_printf(s, "==========>");
652         else
653                 ret = trace_seq_printf(s, "<==========");
654
655         if (!ret)
656                 return TRACE_TYPE_PARTIAL_LINE;
657
658         ret = print_graph_duration(DURATION_FILL_END, s, flags);
659         if (ret != TRACE_TYPE_HANDLED)
660                 return ret;
661
662         ret = trace_seq_printf(s, "\n");
663
664         if (!ret)
665                 return TRACE_TYPE_PARTIAL_LINE;
666         return TRACE_TYPE_HANDLED;
667 }
668
669 enum print_line_t
670 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
671 {
672         unsigned long nsecs_rem = do_div(duration, 1000);
673         /* log10(ULONG_MAX) + '\0' */
674         char msecs_str[21];
675         char nsecs_str[5];
676         int ret, len;
677         int i;
678
679         sprintf(msecs_str, "%lu", (unsigned long) duration);
680
681         /* Print msecs */
682         ret = trace_seq_printf(s, "%s", msecs_str);
683         if (!ret)
684                 return TRACE_TYPE_PARTIAL_LINE;
685
686         len = strlen(msecs_str);
687
688         /* Print nsecs (we don't want to exceed 7 numbers) */
689         if (len < 7) {
690                 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
691
692                 snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
693                 ret = trace_seq_printf(s, ".%s", nsecs_str);
694                 if (!ret)
695                         return TRACE_TYPE_PARTIAL_LINE;
696                 len += strlen(nsecs_str);
697         }
698
699         ret = trace_seq_printf(s, " us ");
700         if (!ret)
701                 return TRACE_TYPE_PARTIAL_LINE;
702
703         /* Print remaining spaces to fit the row's width */
704         for (i = len; i < 7; i++) {
705                 ret = trace_seq_printf(s, " ");
706                 if (!ret)
707                         return TRACE_TYPE_PARTIAL_LINE;
708         }
709         return TRACE_TYPE_HANDLED;
710 }
711
712 static enum print_line_t
713 print_graph_duration(unsigned long long duration, struct trace_seq *s,
714                      u32 flags)
715 {
716         int ret = -1;
717
718         if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
719             !(trace_flags & TRACE_ITER_CONTEXT_INFO))
720                         return TRACE_TYPE_HANDLED;
721
722         /* No real adata, just filling the column with spaces */
723         switch (duration) {
724         case DURATION_FILL_FULL:
725                 ret = trace_seq_printf(s, "              |  ");
726                 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
727         case DURATION_FILL_START:
728                 ret = trace_seq_printf(s, "  ");
729                 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
730         case DURATION_FILL_END:
731                 ret = trace_seq_printf(s, " |");
732                 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
733         }
734
735         /* Signal a overhead of time execution to the output */
736         if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
737                 /* Duration exceeded 100 msecs */
738                 if (duration > 100000ULL)
739                         ret = trace_seq_printf(s, "! ");
740                 /* Duration exceeded 10 msecs */
741                 else if (duration > 10000ULL)
742                         ret = trace_seq_printf(s, "+ ");
743         }
744
745         /*
746          * The -1 means we either did not exceed the duration tresholds
747          * or we dont want to print out the overhead. Either way we need
748          * to fill out the space.
749          */
750         if (ret == -1)
751                 ret = trace_seq_printf(s, "  ");
752
753         /* Catching here any failure happenned above */
754         if (!ret)
755                 return TRACE_TYPE_PARTIAL_LINE;
756
757         ret = trace_print_graph_duration(duration, s);
758         if (ret != TRACE_TYPE_HANDLED)
759                 return ret;
760
761         ret = trace_seq_printf(s, "|  ");
762         if (!ret)
763                 return TRACE_TYPE_PARTIAL_LINE;
764
765         return TRACE_TYPE_HANDLED;
766 }
767
768 /* Case of a leaf function on its call entry */
769 static enum print_line_t
770 print_graph_entry_leaf(struct trace_iterator *iter,
771                 struct ftrace_graph_ent_entry *entry,
772                 struct ftrace_graph_ret_entry *ret_entry,
773                 struct trace_seq *s, u32 flags)
774 {
775         struct fgraph_data *data = iter->private;
776         struct ftrace_graph_ret *graph_ret;
777         struct ftrace_graph_ent *call;
778         unsigned long long duration;
779         int ret;
780         int i;
781
782         graph_ret = &ret_entry->ret;
783         call = &entry->graph_ent;
784         duration = graph_ret->rettime - graph_ret->calltime;
785
786         if (data) {
787                 struct fgraph_cpu_data *cpu_data;
788                 int cpu = iter->cpu;
789
790                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
791
792                 /*
793                  * Comments display at + 1 to depth. Since
794                  * this is a leaf function, keep the comments
795                  * equal to this depth.
796                  */
797                 cpu_data->depth = call->depth - 1;
798
799                 /* No need to keep this function around for this depth */
800                 if (call->depth < FTRACE_RETFUNC_DEPTH)
801                         cpu_data->enter_funcs[call->depth] = 0;
802         }
803
804         /* Overhead and duration */
805         ret = print_graph_duration(duration, s, flags);
806         if (ret == TRACE_TYPE_PARTIAL_LINE)
807                 return TRACE_TYPE_PARTIAL_LINE;
808
809         /* Function */
810         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
811                 ret = trace_seq_printf(s, " ");
812                 if (!ret)
813                         return TRACE_TYPE_PARTIAL_LINE;
814         }
815
816         ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
817         if (!ret)
818                 return TRACE_TYPE_PARTIAL_LINE;
819
820         return TRACE_TYPE_HANDLED;
821 }
822
823 static enum print_line_t
824 print_graph_entry_nested(struct trace_iterator *iter,
825                          struct ftrace_graph_ent_entry *entry,
826                          struct trace_seq *s, int cpu, u32 flags)
827 {
828         struct ftrace_graph_ent *call = &entry->graph_ent;
829         struct fgraph_data *data = iter->private;
830         int ret;
831         int i;
832
833         if (data) {
834                 struct fgraph_cpu_data *cpu_data;
835                 int cpu = iter->cpu;
836
837                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
838                 cpu_data->depth = call->depth;
839
840                 /* Save this function pointer to see if the exit matches */
841                 if (call->depth < FTRACE_RETFUNC_DEPTH)
842                         cpu_data->enter_funcs[call->depth] = call->func;
843         }
844
845         /* No time */
846         ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
847         if (ret != TRACE_TYPE_HANDLED)
848                 return ret;
849
850         /* Function */
851         for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
852                 ret = trace_seq_printf(s, " ");
853                 if (!ret)
854                         return TRACE_TYPE_PARTIAL_LINE;
855         }
856
857         ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
858         if (!ret)
859                 return TRACE_TYPE_PARTIAL_LINE;
860
861         /*
862          * we already consumed the current entry to check the next one
863          * and see if this is a leaf.
864          */
865         return TRACE_TYPE_NO_CONSUME;
866 }
867
868 static enum print_line_t
869 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
870                      int type, unsigned long addr, u32 flags)
871 {
872         struct fgraph_data *data = iter->private;
873         struct trace_entry *ent = iter->ent;
874         int cpu = iter->cpu;
875         int ret;
876
877         /* Pid */
878         if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
879                 return TRACE_TYPE_PARTIAL_LINE;
880
881         if (type) {
882                 /* Interrupt */
883                 ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
884                 if (ret == TRACE_TYPE_PARTIAL_LINE)
885                         return TRACE_TYPE_PARTIAL_LINE;
886         }
887
888         if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
889                 return 0;
890
891         /* Absolute time */
892         if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
893                 ret = print_graph_abs_time(iter->ts, s);
894                 if (!ret)
895                         return TRACE_TYPE_PARTIAL_LINE;
896         }
897
898         /* Cpu */
899         if (flags & TRACE_GRAPH_PRINT_CPU) {
900                 ret = print_graph_cpu(s, cpu);
901                 if (ret == TRACE_TYPE_PARTIAL_LINE)
902                         return TRACE_TYPE_PARTIAL_LINE;
903         }
904
905         /* Proc */
906         if (flags & TRACE_GRAPH_PRINT_PROC) {
907                 ret = print_graph_proc(s, ent->pid);
908                 if (ret == TRACE_TYPE_PARTIAL_LINE)
909                         return TRACE_TYPE_PARTIAL_LINE;
910
911                 ret = trace_seq_printf(s, " | ");
912                 if (!ret)
913                         return TRACE_TYPE_PARTIAL_LINE;
914         }
915
916         /* Latency format */
917         if (trace_flags & TRACE_ITER_LATENCY_FMT) {
918                 ret = print_graph_lat_fmt(s, ent);
919                 if (ret == TRACE_TYPE_PARTIAL_LINE)
920                         return TRACE_TYPE_PARTIAL_LINE;
921         }
922
923         return 0;
924 }
925
926 /*
927  * Entry check for irq code
928  *
929  * returns 1 if
930  *  - we are inside irq code
931  *  - we just entered irq code
932  *
933  * retunns 0 if
934  *  - funcgraph-interrupts option is set
935  *  - we are not inside irq code
936  */
937 static int
938 check_irq_entry(struct trace_iterator *iter, u32 flags,
939                 unsigned long addr, int depth)
940 {
941         int cpu = iter->cpu;
942         int *depth_irq;
943         struct fgraph_data *data = iter->private;
944
945         /*
946          * If we are either displaying irqs, or we got called as
947          * a graph event and private data does not exist,
948          * then we bypass the irq check.
949          */
950         if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
951             (!data))
952                 return 0;
953
954         depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
955
956         /*
957          * We are inside the irq code
958          */
959         if (*depth_irq >= 0)
960                 return 1;
961
962         if ((addr < (unsigned long)__irqentry_text_start) ||
963             (addr >= (unsigned long)__irqentry_text_end))
964                 return 0;
965
966         /*
967          * We are entering irq code.
968          */
969         *depth_irq = depth;
970         return 1;
971 }
972
973 /*
974  * Return check for irq code
975  *
976  * returns 1 if
977  *  - we are inside irq code
978  *  - we just left irq code
979  *
980  * returns 0 if
981  *  - funcgraph-interrupts option is set
982  *  - we are not inside irq code
983  */
984 static int
985 check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
986 {
987         int cpu = iter->cpu;
988         int *depth_irq;
989         struct fgraph_data *data = iter->private;
990
991         /*
992          * If we are either displaying irqs, or we got called as
993          * a graph event and private data does not exist,
994          * then we bypass the irq check.
995          */
996         if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
997             (!data))
998                 return 0;
999
1000         depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1001
1002         /*
1003          * We are not inside the irq code.
1004          */
1005         if (*depth_irq == -1)
1006                 return 0;
1007
1008         /*
1009          * We are inside the irq code, and this is returning entry.
1010          * Let's not trace it and clear the entry depth, since
1011          * we are out of irq code.
1012          *
1013          * This condition ensures that we 'leave the irq code' once
1014          * we are out of the entry depth. Thus protecting us from
1015          * the RETURN entry loss.
1016          */
1017         if (*depth_irq >= depth) {
1018                 *depth_irq = -1;
1019                 return 1;
1020         }
1021
1022         /*
1023          * We are inside the irq code, and this is not the entry.
1024          */
1025         return 1;
1026 }
1027
1028 static enum print_line_t
1029 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
1030                         struct trace_iterator *iter, u32 flags)
1031 {
1032         struct fgraph_data *data = iter->private;
1033         struct ftrace_graph_ent *call = &field->graph_ent;
1034         struct ftrace_graph_ret_entry *leaf_ret;
1035         static enum print_line_t ret;
1036         int cpu = iter->cpu;
1037
1038         if (check_irq_entry(iter, flags, call->func, call->depth))
1039                 return TRACE_TYPE_HANDLED;
1040
1041         if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
1042                 return TRACE_TYPE_PARTIAL_LINE;
1043
1044         leaf_ret = get_return_for_leaf(iter, field);
1045         if (leaf_ret)
1046                 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
1047         else
1048                 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
1049
1050         if (data) {
1051                 /*
1052                  * If we failed to write our output, then we need to make
1053                  * note of it. Because we already consumed our entry.
1054                  */
1055                 if (s->full) {
1056                         data->failed = 1;
1057                         data->cpu = cpu;
1058                 } else
1059                         data->failed = 0;
1060         }
1061
1062         return ret;
1063 }
1064
1065 static enum print_line_t
1066 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
1067                    struct trace_entry *ent, struct trace_iterator *iter,
1068                    u32 flags)
1069 {
1070         unsigned long long duration = trace->rettime - trace->calltime;
1071         struct fgraph_data *data = iter->private;
1072         pid_t pid = ent->pid;
1073         int cpu = iter->cpu;
1074         int func_match = 1;
1075         int ret;
1076         int i;
1077
1078         if (check_irq_return(iter, flags, trace->depth))
1079                 return TRACE_TYPE_HANDLED;
1080
1081         if (data) {
1082                 struct fgraph_cpu_data *cpu_data;
1083                 int cpu = iter->cpu;
1084
1085                 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1086
1087                 /*
1088                  * Comments display at + 1 to depth. This is the
1089                  * return from a function, we now want the comments
1090                  * to display at the same level of the bracket.
1091                  */
1092                 cpu_data->depth = trace->depth - 1;
1093
1094                 if (trace->depth < FTRACE_RETFUNC_DEPTH) {
1095                         if (cpu_data->enter_funcs[trace->depth] != trace->func)
1096                                 func_match = 0;
1097                         cpu_data->enter_funcs[trace->depth] = 0;
1098                 }
1099         }
1100
1101         if (print_graph_prologue(iter, s, 0, 0, flags))
1102                 return TRACE_TYPE_PARTIAL_LINE;
1103
1104         /* Overhead and duration */
1105         ret = print_graph_duration(duration, s, flags);
1106         if (ret == TRACE_TYPE_PARTIAL_LINE)
1107                 return TRACE_TYPE_PARTIAL_LINE;
1108
1109         /* Closing brace */
1110         for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
1111                 ret = trace_seq_printf(s, " ");
1112                 if (!ret)
1113                         return TRACE_TYPE_PARTIAL_LINE;
1114         }
1115
1116         /*
1117          * If the return function does not have a matching entry,
1118          * then the entry was lost. Instead of just printing
1119          * the '}' and letting the user guess what function this
1120          * belongs to, write out the function name.
1121          */
1122         if (func_match) {
1123                 ret = trace_seq_printf(s, "}\n");
1124                 if (!ret)
1125                         return TRACE_TYPE_PARTIAL_LINE;
1126         } else {
1127                 ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
1128                 if (!ret)
1129                         return TRACE_TYPE_PARTIAL_LINE;
1130         }
1131
1132         /* Overrun */
1133         if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
1134                 ret = trace_seq_printf(s, " (Overruns: %lu)\n",
1135                                         trace->overrun);
1136                 if (!ret)
1137                         return TRACE_TYPE_PARTIAL_LINE;
1138         }
1139
1140         ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
1141                               cpu, pid, flags);
1142         if (ret == TRACE_TYPE_PARTIAL_LINE)
1143                 return TRACE_TYPE_PARTIAL_LINE;
1144
1145         return TRACE_TYPE_HANDLED;
1146 }
1147
1148 static enum print_line_t
1149 print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
1150                     struct trace_iterator *iter, u32 flags)
1151 {
1152         unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1153         struct fgraph_data *data = iter->private;
1154         struct trace_event *event;
1155         int depth = 0;
1156         int ret;
1157         int i;
1158
1159         if (data)
1160                 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
1161
1162         if (print_graph_prologue(iter, s, 0, 0, flags))
1163                 return TRACE_TYPE_PARTIAL_LINE;
1164
1165         /* No time */
1166         ret = print_graph_duration(DURATION_FILL_FULL, s, flags);
1167         if (ret != TRACE_TYPE_HANDLED)
1168                 return ret;
1169
1170         /* Indentation */
1171         if (depth > 0)
1172                 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
1173                         ret = trace_seq_printf(s, " ");
1174                         if (!ret)
1175                                 return TRACE_TYPE_PARTIAL_LINE;
1176                 }
1177
1178         /* The comment */
1179         ret = trace_seq_printf(s, "/* ");
1180         if (!ret)
1181                 return TRACE_TYPE_PARTIAL_LINE;
1182
1183         switch (iter->ent->type) {
1184         case TRACE_BPRINT:
1185                 ret = trace_print_bprintk_msg_only(iter);
1186                 if (ret != TRACE_TYPE_HANDLED)
1187                         return ret;
1188                 break;
1189         case TRACE_PRINT:
1190                 ret = trace_print_printk_msg_only(iter);
1191                 if (ret != TRACE_TYPE_HANDLED)
1192                         return ret;
1193                 break;
1194         default:
1195                 event = ftrace_find_event(ent->type);
1196                 if (!event)
1197                         return TRACE_TYPE_UNHANDLED;
1198
1199                 ret = event->funcs->trace(iter, sym_flags, event);
1200                 if (ret != TRACE_TYPE_HANDLED)
1201                         return ret;
1202         }
1203
1204         /* Strip ending newline */
1205         if (s->buffer[s->len - 1] == '\n') {
1206                 s->buffer[s->len - 1] = '\0';
1207                 s->len--;
1208         }
1209
1210         ret = trace_seq_printf(s, " */\n");
1211         if (!ret)
1212                 return TRACE_TYPE_PARTIAL_LINE;
1213
1214         return TRACE_TYPE_HANDLED;
1215 }
1216
1217
1218 enum print_line_t
1219 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1220 {
1221         struct ftrace_graph_ent_entry *field;
1222         struct fgraph_data *data = iter->private;
1223         struct trace_entry *entry = iter->ent;
1224         struct trace_seq *s = &iter->seq;
1225         int cpu = iter->cpu;
1226         int ret;
1227
1228         if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1229                 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1230                 return TRACE_TYPE_HANDLED;
1231         }
1232
1233         /*
1234          * If the last output failed, there's a possibility we need
1235          * to print out the missing entry which would never go out.
1236          */
1237         if (data && data->failed) {
1238                 field = &data->ent;
1239                 iter->cpu = data->cpu;
1240                 ret = print_graph_entry(field, s, iter, flags);
1241                 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1242                         per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1243                         ret = TRACE_TYPE_NO_CONSUME;
1244                 }
1245                 iter->cpu = cpu;
1246                 return ret;
1247         }
1248
1249         switch (entry->type) {
1250         case TRACE_GRAPH_ENT: {
1251                 /*
1252                  * print_graph_entry() may consume the current event,
1253                  * thus @field may become invalid, so we need to save it.
1254                  * sizeof(struct ftrace_graph_ent_entry) is very small,
1255                  * it can be safely saved at the stack.
1256                  */
1257                 struct ftrace_graph_ent_entry saved;
1258                 trace_assign_type(field, entry);
1259                 saved = *field;
1260                 return print_graph_entry(&saved, s, iter, flags);
1261         }
1262         case TRACE_GRAPH_RET: {
1263                 struct ftrace_graph_ret_entry *field;
1264                 trace_assign_type(field, entry);
1265                 return print_graph_return(&field->ret, s, entry, iter, flags);
1266         }
1267         case TRACE_STACK:
1268         case TRACE_FN:
1269                 /* dont trace stack and functions as comments */
1270                 return TRACE_TYPE_UNHANDLED;
1271
1272         default:
1273                 return print_graph_comment(s, entry, iter, flags);
1274         }
1275
1276         return TRACE_TYPE_HANDLED;
1277 }
1278
1279 static enum print_line_t
1280 print_graph_function(struct trace_iterator *iter)
1281 {
1282         return print_graph_function_flags(iter, tracer_flags.val);
1283 }
1284
1285 static enum print_line_t
1286 print_graph_function_event(struct trace_iterator *iter, int flags,
1287                            struct trace_event *event)
1288 {
1289         return print_graph_function(iter);
1290 }
1291
1292 static void print_lat_header(struct seq_file *s, u32 flags)
1293 {
1294         static const char spaces[] = "                " /* 16 spaces */
1295                 "    "                                  /* 4 spaces */
1296                 "                 ";                    /* 17 spaces */
1297         int size = 0;
1298
1299         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1300                 size += 16;
1301         if (flags & TRACE_GRAPH_PRINT_CPU)
1302                 size += 4;
1303         if (flags & TRACE_GRAPH_PRINT_PROC)
1304                 size += 17;
1305
1306         seq_printf(s, "#%.*s  _-----=> irqs-off        \n", size, spaces);
1307         seq_printf(s, "#%.*s / _----=> need-resched    \n", size, spaces);
1308         seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1309         seq_printf(s, "#%.*s|| / _--=> preempt-depth   \n", size, spaces);
1310         seq_printf(s, "#%.*s||| /                      \n", size, spaces);
1311 }
1312
1313 static void __print_graph_headers_flags(struct seq_file *s, u32 flags)
1314 {
1315         int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
1316
1317         if (lat)
1318                 print_lat_header(s, flags);
1319
1320         /* 1st line */
1321         seq_printf(s, "#");
1322         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1323                 seq_printf(s, "     TIME       ");
1324         if (flags & TRACE_GRAPH_PRINT_CPU)
1325                 seq_printf(s, " CPU");
1326         if (flags & TRACE_GRAPH_PRINT_PROC)
1327                 seq_printf(s, "  TASK/PID       ");
1328         if (lat)
1329                 seq_printf(s, "||||");
1330         if (flags & TRACE_GRAPH_PRINT_DURATION)
1331                 seq_printf(s, "  DURATION   ");
1332         seq_printf(s, "               FUNCTION CALLS\n");
1333
1334         /* 2nd line */
1335         seq_printf(s, "#");
1336         if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1337                 seq_printf(s, "      |         ");
1338         if (flags & TRACE_GRAPH_PRINT_CPU)
1339                 seq_printf(s, " |  ");
1340         if (flags & TRACE_GRAPH_PRINT_PROC)
1341                 seq_printf(s, "   |    |        ");
1342         if (lat)
1343                 seq_printf(s, "||||");
1344         if (flags & TRACE_GRAPH_PRINT_DURATION)
1345                 seq_printf(s, "   |   |      ");
1346         seq_printf(s, "               |   |   |   |\n");
1347 }
1348
1349 void print_graph_headers(struct seq_file *s)
1350 {
1351         print_graph_headers_flags(s, tracer_flags.val);
1352 }
1353
1354 void print_graph_headers_flags(struct seq_file *s, u32 flags)
1355 {
1356         struct trace_iterator *iter = s->private;
1357
1358         if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
1359                 return;
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         }
1368
1369         __print_graph_headers_flags(s, flags);
1370 }
1371
1372 void graph_trace_open(struct trace_iterator *iter)
1373 {
1374         /* pid and depth on the last trace processed */
1375         struct fgraph_data *data;
1376         int cpu;
1377
1378         iter->private = NULL;
1379
1380         data = kzalloc(sizeof(*data), GFP_KERNEL);
1381         if (!data)
1382                 goto out_err;
1383
1384         data->cpu_data = alloc_percpu(struct fgraph_cpu_data);
1385         if (!data->cpu_data)
1386                 goto out_err_free;
1387
1388         for_each_possible_cpu(cpu) {
1389                 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1390                 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1391                 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1392                 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1393
1394                 *pid = -1;
1395                 *depth = 0;
1396                 *ignore = 0;
1397                 *depth_irq = -1;
1398         }
1399
1400         iter->private = data;
1401
1402         return;
1403
1404  out_err_free:
1405         kfree(data);
1406  out_err:
1407         pr_warning("function graph tracer: not enough memory\n");
1408 }
1409
1410 void graph_trace_close(struct trace_iterator *iter)
1411 {
1412         struct fgraph_data *data = iter->private;
1413
1414         if (data) {
1415                 free_percpu(data->cpu_data);
1416                 kfree(data);
1417         }
1418 }
1419
1420 static int func_graph_set_flag(u32 old_flags, u32 bit, int set)
1421 {
1422         if (bit == TRACE_GRAPH_PRINT_IRQS)
1423                 ftrace_graph_skip_irqs = !set;
1424
1425         return 0;
1426 }
1427
1428 static struct trace_event_functions graph_functions = {
1429         .trace          = print_graph_function_event,
1430 };
1431
1432 static struct trace_event graph_trace_entry_event = {
1433         .type           = TRACE_GRAPH_ENT,
1434         .funcs          = &graph_functions,
1435 };
1436
1437 static struct trace_event graph_trace_ret_event = {
1438         .type           = TRACE_GRAPH_RET,
1439         .funcs          = &graph_functions
1440 };
1441
1442 static struct tracer graph_trace __read_mostly = {
1443         .name           = "function_graph",
1444         .open           = graph_trace_open,
1445         .pipe_open      = graph_trace_open,
1446         .close          = graph_trace_close,
1447         .pipe_close     = graph_trace_close,
1448         .wait_pipe      = poll_wait_pipe,
1449         .init           = graph_trace_init,
1450         .reset          = graph_trace_reset,
1451         .print_line     = print_graph_function,
1452         .print_header   = print_graph_headers,
1453         .flags          = &tracer_flags,
1454         .set_flag       = func_graph_set_flag,
1455 #ifdef CONFIG_FTRACE_SELFTEST
1456         .selftest       = trace_selftest_startup_function_graph,
1457 #endif
1458 };
1459
1460 static __init int init_graph_trace(void)
1461 {
1462         max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
1463
1464         if (!register_ftrace_event(&graph_trace_entry_event)) {
1465                 pr_warning("Warning: could not register graph trace events\n");
1466                 return 1;
1467         }
1468
1469         if (!register_ftrace_event(&graph_trace_ret_event)) {
1470                 pr_warning("Warning: could not register graph trace events\n");
1471                 return 1;
1472         }
1473
1474         return register_tracer(&graph_trace);
1475 }
1476
1477 core_initcall(init_graph_trace);