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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux/fpc-iii.git] / kernel / trace / trace_functions_graph.c
blob0b99120d395cc166583e400e80108b7d07540935
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 unsigned int max_depth;
51
52 static struct tracer_opt trace_opts[] = {
53 /* Display overruns? (for self-debug purpose) */
54 { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
55 /* Display CPU ? */
56 { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
57 /* Display Overhead ? */
58 { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
59 /* Display proc name/pid */
60 { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
61 /* Display duration of execution */
62 { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
63 /* Display absolute time of an entry */
64 { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
65 /* Display interrupts */
66 { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
67 { } /* Empty entry */
68 };
69
70 static struct tracer_flags tracer_flags = {
71 /* Don't display overruns and proc by default */
72 .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
73 TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS,
74 .opts = trace_opts
75 };
76
77 static struct trace_array *graph_array;
78
79 /*
80 * DURATION column is being also used to display IRQ signs,
81 * following values are used by print_graph_irq and others
82 * to fill in space into DURATION column.
83 */
84 enum {
85 FLAGS_FILL_FULL = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT,
86 FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT,
87 FLAGS_FILL_END = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT,
88 };
89
90 static enum print_line_t
91 print_graph_duration(unsigned long long duration, struct trace_seq *s,
92 u32 flags);
93
94 /* Add a function return address to the trace stack on thread info.*/
95 int
96 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
97 unsigned long frame_pointer)
98 {
99 unsigned long long calltime;
100 int index;
101
102 if (!current->ret_stack)
103 return -EBUSY;
104
105 /*
106 * We must make sure the ret_stack is tested before we read
107 * anything else.
108 */
109 smp_rmb();
110
111 /* The return trace stack is full */
112 if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
113 atomic_inc(&current->trace_overrun);
114 return -EBUSY;
115 }
116
117 /*
118 * The curr_ret_stack is an index to ftrace return stack of
119 * current task. Its value should be in [0, FTRACE_RETFUNC_
120 * DEPTH) when the function graph tracer is used. To support
121 * filtering out specific functions, it makes the index
122 * negative by subtracting huge value (FTRACE_NOTRACE_DEPTH)
123 * so when it sees a negative index the ftrace will ignore
124 * the record. And the index gets recovered when returning
125 * from the filtered function by adding the FTRACE_NOTRACE_
126 * DEPTH and then it'll continue to record functions normally.
127 *
128 * The curr_ret_stack is initialized to -1 and get increased
129 * in this function. So it can be less than -1 only if it was
130 * filtered out via ftrace_graph_notrace_addr() which can be
131 * set from set_graph_notrace file in debugfs by user.
132 */
133 if (current->curr_ret_stack < -1)
134 return -EBUSY;
135
136 calltime = trace_clock_local();
137
138 index = ++current->curr_ret_stack;
139 if (ftrace_graph_notrace_addr(func))
140 current->curr_ret_stack -= FTRACE_NOTRACE_DEPTH;
141 barrier();
142 current->ret_stack[index].ret = ret;
143 current->ret_stack[index].func = func;
144 current->ret_stack[index].calltime = calltime;
145 current->ret_stack[index].subtime = 0;
146 current->ret_stack[index].fp = frame_pointer;
147 *depth = current->curr_ret_stack;
148
149 return 0;
150 }
151
152 /* Retrieve a function return address to the trace stack on thread info.*/
153 static void
154 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
155 unsigned long frame_pointer)
156 {
157 int index;
158
159 index = current->curr_ret_stack;
160
161 /*
162 * A negative index here means that it's just returned from a
163 * notrace'd function. Recover index to get an original
164 * return address. See ftrace_push_return_trace().
165 *
166 * TODO: Need to check whether the stack gets corrupted.
167 */
168 if (index < 0)
169 index += FTRACE_NOTRACE_DEPTH;
170
171 if (unlikely(index < 0 || index >= FTRACE_RETFUNC_DEPTH)) {
172 ftrace_graph_stop();
173 WARN_ON(1);
174 /* Might as well panic, otherwise we have no where to go */
175 *ret = (unsigned long)panic;
176 return;
177 }
178
179 #if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY)
180 /*
181 * The arch may choose to record the frame pointer used
182 * and check it here to make sure that it is what we expect it
183 * to be. If gcc does not set the place holder of the return
184 * address in the frame pointer, and does a copy instead, then
185 * the function graph trace will fail. This test detects this
186 * case.
187 *
188 * Currently, x86_32 with optimize for size (-Os) makes the latest
189 * gcc do the above.
190 *
191 * Note, -mfentry does not use frame pointers, and this test
192 * is not needed if CC_USING_FENTRY is set.
193 */
194 if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
195 ftrace_graph_stop();
196 WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
197 " from func %ps return to %lx\n",
198 current->ret_stack[index].fp,
199 frame_pointer,
200 (void *)current->ret_stack[index].func,
201 current->ret_stack[index].ret);
202 *ret = (unsigned long)panic;
203 return;
204 }
205 #endif
206
207 *ret = current->ret_stack[index].ret;
208 trace->func = current->ret_stack[index].func;
209 trace->calltime = current->ret_stack[index].calltime;
210 trace->overrun = atomic_read(&current->trace_overrun);
211 trace->depth = index;
212 }
213
214 /*
215 * Send the trace to the ring-buffer.
216 * @return the original return address.
217 */
218 unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
219 {
220 struct ftrace_graph_ret trace;
221 unsigned long ret;
222
223 ftrace_pop_return_trace(&trace, &ret, frame_pointer);
224 trace.rettime = trace_clock_local();
225 barrier();
226 current->curr_ret_stack--;
227 /*
228 * The curr_ret_stack can be less than -1 only if it was
229 * filtered out and it's about to return from the function.
230 * Recover the index and continue to trace normal functions.
231 */
232 if (current->curr_ret_stack < -1) {
233 current->curr_ret_stack += FTRACE_NOTRACE_DEPTH;
234 return ret;
235 }
236
237 /*
238 * The trace should run after decrementing the ret counter
239 * in case an interrupt were to come in. We don't want to
240 * lose the interrupt if max_depth is set.
241 */
242 ftrace_graph_return(&trace);
243
244 if (unlikely(!ret)) {
245 ftrace_graph_stop();
246 WARN_ON(1);
247 /* Might as well panic. What else to do? */
248 ret = (unsigned long)panic;
249 }
250
251 return ret;
252 }
253
254 int __trace_graph_entry(struct trace_array *tr,
255 struct ftrace_graph_ent *trace,
256 unsigned long flags,
257 int pc)
258 {
259 struct ftrace_event_call *call = &event_funcgraph_entry;
260 struct ring_buffer_event *event;
261 struct ring_buffer *buffer = tr->trace_buffer.buffer;
262 struct ftrace_graph_ent_entry *entry;
263
264 if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
265 return 0;
266
267 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
268 sizeof(*entry), flags, pc);
269 if (!event)
270 return 0;
271 entry = ring_buffer_event_data(event);
272 entry->graph_ent = *trace;
273 if (!call_filter_check_discard(call, entry, buffer, event))
274 __buffer_unlock_commit(buffer, event);
275
276 return 1;
277 }
278
279 static inline int ftrace_graph_ignore_irqs(void)
280 {
281 if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
282 return 0;
283
284 return in_irq();
285 }
286
287 int trace_graph_entry(struct ftrace_graph_ent *trace)
288 {
289 struct trace_array *tr = graph_array;
290 struct trace_array_cpu *data;
291 unsigned long flags;
292 long disabled;
293 int ret;
294 int cpu;
295 int pc;
296
297 if (!ftrace_trace_task(current))
298 return 0;
299
300 /* trace it when it is-nested-in or is a function enabled. */
301 if ((!(trace->depth || ftrace_graph_addr(trace->func)) ||
302 ftrace_graph_ignore_irqs()) || (trace->depth < 0) ||
303 (max_depth && trace->depth >= max_depth))
304 return 0;
305
306 /*
307 * Do not trace a function if it's filtered by set_graph_notrace.
308 * Make the index of ret stack negative to indicate that it should
309 * ignore further functions. But it needs its own ret stack entry
310 * to recover the original index in order to continue tracing after
311 * returning from the function.
312 */
313 if (ftrace_graph_notrace_addr(trace->func))
314 return 1;
315
316 local_irq_save(flags);
317 cpu = raw_smp_processor_id();
318 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
319 disabled = atomic_inc_return(&data->disabled);
320 if (likely(disabled == 1)) {
321 pc = preempt_count();
322 ret = __trace_graph_entry(tr, trace, flags, pc);
323 } else {
324 ret = 0;
325 }
326
327 atomic_dec(&data->disabled);
328 local_irq_restore(flags);
329
330 return ret;
331 }
332
333 int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
334 {
335 if (tracing_thresh)
336 return 1;
337 else
338 return trace_graph_entry(trace);
339 }
340
341 static void
342 __trace_graph_function(struct trace_array *tr,
343 unsigned long ip, unsigned long flags, int pc)
344 {
345 u64 time = trace_clock_local();
346 struct ftrace_graph_ent ent = {
347 .func = ip,
348 .depth = 0,
349 };
350 struct ftrace_graph_ret ret = {
351 .func = ip,
352 .depth = 0,
353 .calltime = time,
354 .rettime = time,
355 };
356
357 __trace_graph_entry(tr, &ent, flags, pc);
358 __trace_graph_return(tr, &ret, flags, pc);
359 }
360
361 void
362 trace_graph_function(struct trace_array *tr,
363 unsigned long ip, unsigned long parent_ip,
364 unsigned long flags, int pc)
365 {
366 __trace_graph_function(tr, ip, flags, pc);
367 }
368
369 void __trace_graph_return(struct trace_array *tr,
370 struct ftrace_graph_ret *trace,
371 unsigned long flags,
372 int pc)
373 {
374 struct ftrace_event_call *call = &event_funcgraph_exit;
375 struct ring_buffer_event *event;
376 struct ring_buffer *buffer = tr->trace_buffer.buffer;
377 struct ftrace_graph_ret_entry *entry;
378
379 if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
380 return;
381
382 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
383 sizeof(*entry), flags, pc);
384 if (!event)
385 return;
386 entry = ring_buffer_event_data(event);
387 entry->ret = *trace;
388 if (!call_filter_check_discard(call, entry, buffer, event))
389 __buffer_unlock_commit(buffer, event);
390 }
391
392 void trace_graph_return(struct ftrace_graph_ret *trace)
393 {
394 struct trace_array *tr = graph_array;
395 struct trace_array_cpu *data;
396 unsigned long flags;
397 long disabled;
398 int cpu;
399 int pc;
400
401 local_irq_save(flags);
402 cpu = raw_smp_processor_id();
403 data = per_cpu_ptr(tr->trace_buffer.data, cpu);
404 disabled = atomic_inc_return(&data->disabled);
405 if (likely(disabled == 1)) {
406 pc = preempt_count();
407 __trace_graph_return(tr, trace, flags, pc);
408 }
409 atomic_dec(&data->disabled);
410 local_irq_restore(flags);
411 }
412
413 void set_graph_array(struct trace_array *tr)
414 {
415 graph_array = tr;
416
417 /* Make graph_array visible before we start tracing */
418
419 smp_mb();
420 }
421
422 void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
423 {
424 if (tracing_thresh &&
425 (trace->rettime - trace->calltime < tracing_thresh))
426 return;
427 else
428 trace_graph_return(trace);
429 }
430
431 static int graph_trace_init(struct trace_array *tr)
432 {
433 int ret;
434
435 set_graph_array(tr);
436 if (tracing_thresh)
437 ret = register_ftrace_graph(&trace_graph_thresh_return,
438 &trace_graph_thresh_entry);
439 else
440 ret = register_ftrace_graph(&trace_graph_return,
441 &trace_graph_entry);
442 if (ret)
443 return ret;
444 tracing_start_cmdline_record();
445
446 return 0;
447 }
448
449 static void graph_trace_reset(struct trace_array *tr)
450 {
451 tracing_stop_cmdline_record();
452 unregister_ftrace_graph();
453 }
454
455 static int max_bytes_for_cpu;
456
457 static enum print_line_t
458 print_graph_cpu(struct trace_seq *s, int cpu)
459 {
460 int ret;
461
462 /*
463 * Start with a space character - to make it stand out
464 * to the right a bit when trace output is pasted into
465 * email:
466 */
467 ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
468 if (!ret)
469 return TRACE_TYPE_PARTIAL_LINE;
470
471 return TRACE_TYPE_HANDLED;
472 }
473
474 #define TRACE_GRAPH_PROCINFO_LENGTH 14
475
476 static enum print_line_t
477 print_graph_proc(struct trace_seq *s, pid_t pid)
478 {
479 char comm[TASK_COMM_LEN];
480 /* sign + log10(MAX_INT) + '\0' */
481 char pid_str[11];
482 int spaces = 0;
483 int ret;
484 int len;
485 int i;
486
487 trace_find_cmdline(pid, comm);
488 comm[7] = '\0';
489 sprintf(pid_str, "%d", pid);
490
491 /* 1 stands for the "-" character */
492 len = strlen(comm) + strlen(pid_str) + 1;
493
494 if (len < TRACE_GRAPH_PROCINFO_LENGTH)
495 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
496
497 /* First spaces to align center */
498 for (i = 0; i < spaces / 2; i++) {
499 ret = trace_seq_putc(s, ' ');
500 if (!ret)
501 return TRACE_TYPE_PARTIAL_LINE;
502 }
503
504 ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
505 if (!ret)
506 return TRACE_TYPE_PARTIAL_LINE;
507
508 /* Last spaces to align center */
509 for (i = 0; i < spaces - (spaces / 2); i++) {
510 ret = trace_seq_putc(s, ' ');
511 if (!ret)
512 return TRACE_TYPE_PARTIAL_LINE;
513 }
514 return TRACE_TYPE_HANDLED;
515 }
516
517
518 static enum print_line_t
519 print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
520 {
521 if (!trace_seq_putc(s, ' '))
522 return 0;
523
524 return trace_print_lat_fmt(s, entry);
525 }
526
527 /* If the pid changed since the last trace, output this event */
528 static enum print_line_t
529 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
530 {
531 pid_t prev_pid;
532 pid_t *last_pid;
533 int ret;
534
535 if (!data)
536 return TRACE_TYPE_HANDLED;
537
538 last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
539
540 if (*last_pid == pid)
541 return TRACE_TYPE_HANDLED;
542
543 prev_pid = *last_pid;
544 *last_pid = pid;
545
546 if (prev_pid == -1)
547 return TRACE_TYPE_HANDLED;
548 /*
549 * Context-switch trace line:
550
551 ------------------------------------------
552 | 1) migration/0--1 => sshd-1755
553 ------------------------------------------
554
555 */
556 ret = trace_seq_puts(s,
557 " ------------------------------------------\n");
558 if (!ret)
559 return TRACE_TYPE_PARTIAL_LINE;
560
561 ret = print_graph_cpu(s, cpu);
562 if (ret == TRACE_TYPE_PARTIAL_LINE)
563 return TRACE_TYPE_PARTIAL_LINE;
564
565 ret = print_graph_proc(s, prev_pid);
566 if (ret == TRACE_TYPE_PARTIAL_LINE)
567 return TRACE_TYPE_PARTIAL_LINE;
568
569 ret = trace_seq_puts(s, " => ");
570 if (!ret)
571 return TRACE_TYPE_PARTIAL_LINE;
572
573 ret = print_graph_proc(s, pid);
574 if (ret == TRACE_TYPE_PARTIAL_LINE)
575 return TRACE_TYPE_PARTIAL_LINE;
576
577 ret = trace_seq_puts(s,
578 "\n ------------------------------------------\n\n");
579 if (!ret)
580 return TRACE_TYPE_PARTIAL_LINE;
581
582 return TRACE_TYPE_HANDLED;
583 }
584
585 static struct ftrace_graph_ret_entry *
586 get_return_for_leaf(struct trace_iterator *iter,
587 struct ftrace_graph_ent_entry *curr)
588 {
589 struct fgraph_data *data = iter->private;
590 struct ring_buffer_iter *ring_iter = NULL;
591 struct ring_buffer_event *event;
592 struct ftrace_graph_ret_entry *next;
593
594 /*
595 * If the previous output failed to write to the seq buffer,
596 * then we just reuse the data from before.
597 */
598 if (data && data->failed) {
599 curr = &data->ent;
600 next = &data->ret;
601 } else {
602
603 ring_iter = trace_buffer_iter(iter, iter->cpu);
604
605 /* First peek to compare current entry and the next one */
606 if (ring_iter)
607 event = ring_buffer_iter_peek(ring_iter, NULL);
608 else {
609 /*
610 * We need to consume the current entry to see
611 * the next one.
612 */
613 ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu,
614 NULL, NULL);
615 event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu,
616 NULL, NULL);
617 }
618
619 if (!event)
620 return NULL;
621
622 next = ring_buffer_event_data(event);
623
624 if (data) {
625 /*
626 * Save current and next entries for later reference
627 * if the output fails.
628 */
629 data->ent = *curr;
630 /*
631 * If the next event is not a return type, then
632 * we only care about what type it is. Otherwise we can
633 * safely copy the entire event.
634 */
635 if (next->ent.type == TRACE_GRAPH_RET)
636 data->ret = *next;
637 else
638 data->ret.ent.type = next->ent.type;
639 }
640 }
641
642 if (next->ent.type != TRACE_GRAPH_RET)
643 return NULL;
644
645 if (curr->ent.pid != next->ent.pid ||
646 curr->graph_ent.func != next->ret.func)
647 return NULL;
648
649 /* this is a leaf, now advance the iterator */
650 if (ring_iter)
651 ring_buffer_read(ring_iter, NULL);
652
653 return next;
654 }
655
656 static int print_graph_abs_time(u64 t, struct trace_seq *s)
657 {
658 unsigned long usecs_rem;
659
660 usecs_rem = do_div(t, NSEC_PER_SEC);
661 usecs_rem /= 1000;
662
663 return trace_seq_printf(s, "%5lu.%06lu | ",
664 (unsigned long)t, usecs_rem);
665 }
666
667 static enum print_line_t
668 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
669 enum trace_type type, int cpu, pid_t pid, u32 flags)
670 {
671 int ret;
672 struct trace_seq *s = &iter->seq;
673
674 if (addr < (unsigned long)__irqentry_text_start ||
675 addr >= (unsigned long)__irqentry_text_end)
676 return TRACE_TYPE_UNHANDLED;
677
678 if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
679 /* Absolute time */
680 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
681 ret = print_graph_abs_time(iter->ts, s);
682 if (!ret)
683 return TRACE_TYPE_PARTIAL_LINE;
684 }
685
686 /* Cpu */
687 if (flags & TRACE_GRAPH_PRINT_CPU) {
688 ret = print_graph_cpu(s, cpu);
689 if (ret == TRACE_TYPE_PARTIAL_LINE)
690 return TRACE_TYPE_PARTIAL_LINE;
691 }
692
693 /* Proc */
694 if (flags & TRACE_GRAPH_PRINT_PROC) {
695 ret = print_graph_proc(s, pid);
696 if (ret == TRACE_TYPE_PARTIAL_LINE)
697 return TRACE_TYPE_PARTIAL_LINE;
698 ret = trace_seq_puts(s, " | ");
699 if (!ret)
700 return TRACE_TYPE_PARTIAL_LINE;
701 }
702 }
703
704 /* No overhead */
705 ret = print_graph_duration(0, s, flags | FLAGS_FILL_START);
706 if (ret != TRACE_TYPE_HANDLED)
707 return ret;
708
709 if (type == TRACE_GRAPH_ENT)
710 ret = trace_seq_puts(s, "==========>");
711 else
712 ret = trace_seq_puts(s, "<==========");
713
714 if (!ret)
715 return TRACE_TYPE_PARTIAL_LINE;
716
717 ret = print_graph_duration(0, s, flags | FLAGS_FILL_END);
718 if (ret != TRACE_TYPE_HANDLED)
719 return ret;
720
721 ret = trace_seq_putc(s, '\n');
722
723 if (!ret)
724 return TRACE_TYPE_PARTIAL_LINE;
725 return TRACE_TYPE_HANDLED;
726 }
727
728 enum print_line_t
729 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
730 {
731 unsigned long nsecs_rem = do_div(duration, 1000);
732 /* log10(ULONG_MAX) + '\0' */
733 char msecs_str[21];
734 char nsecs_str[5];
735 int ret, len;
736 int i;
737
738 sprintf(msecs_str, "%lu", (unsigned long) duration);
739
740 /* Print msecs */
741 ret = trace_seq_printf(s, "%s", msecs_str);
742 if (!ret)
743 return TRACE_TYPE_PARTIAL_LINE;
744
745 len = strlen(msecs_str);
746
747 /* Print nsecs (we don't want to exceed 7 numbers) */
748 if (len < 7) {
749 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
750
751 snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
752 ret = trace_seq_printf(s, ".%s", nsecs_str);
753 if (!ret)
754 return TRACE_TYPE_PARTIAL_LINE;
755 len += strlen(nsecs_str);
756 }
757
758 ret = trace_seq_puts(s, " us ");
759 if (!ret)
760 return TRACE_TYPE_PARTIAL_LINE;
761
762 /* Print remaining spaces to fit the row's width */
763 for (i = len; i < 7; i++) {
764 ret = trace_seq_putc(s, ' ');
765 if (!ret)
766 return TRACE_TYPE_PARTIAL_LINE;
767 }
768 return TRACE_TYPE_HANDLED;
769 }
770
771 static enum print_line_t
772 print_graph_duration(unsigned long long duration, struct trace_seq *s,
773 u32 flags)
774 {
775 int ret = -1;
776
777 if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
778 !(trace_flags & TRACE_ITER_CONTEXT_INFO))
779 return TRACE_TYPE_HANDLED;
780
781 /* No real adata, just filling the column with spaces */
782 switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
783 case FLAGS_FILL_FULL:
784 ret = trace_seq_puts(s, " | ");
785 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
786 case FLAGS_FILL_START:
787 ret = trace_seq_puts(s, " ");
788 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
789 case FLAGS_FILL_END:
790 ret = trace_seq_puts(s, " |");
791 return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
792 }
793
794 /* Signal a overhead of time execution to the output */
795 if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
796 /* Duration exceeded 100 msecs */
797 if (duration > 100000ULL)
798 ret = trace_seq_puts(s, "! ");
799 /* Duration exceeded 10 msecs */
800 else if (duration > 10000ULL)
801 ret = trace_seq_puts(s, "+ ");
802 }
803
804 /*
805 * The -1 means we either did not exceed the duration tresholds
806 * or we dont want to print out the overhead. Either way we need
807 * to fill out the space.
808 */
809 if (ret == -1)
810 ret = trace_seq_puts(s, " ");
811
812 /* Catching here any failure happenned above */
813 if (!ret)
814 return TRACE_TYPE_PARTIAL_LINE;
815
816 ret = trace_print_graph_duration(duration, s);
817 if (ret != TRACE_TYPE_HANDLED)
818 return ret;
819
820 ret = trace_seq_puts(s, "| ");
821 if (!ret)
822 return TRACE_TYPE_PARTIAL_LINE;
823
824 return TRACE_TYPE_HANDLED;
825 }
826
827 /* Case of a leaf function on its call entry */
828 static enum print_line_t
829 print_graph_entry_leaf(struct trace_iterator *iter,
830 struct ftrace_graph_ent_entry *entry,
831 struct ftrace_graph_ret_entry *ret_entry,
832 struct trace_seq *s, u32 flags)
833 {
834 struct fgraph_data *data = iter->private;
835 struct ftrace_graph_ret *graph_ret;
836 struct ftrace_graph_ent *call;
837 unsigned long long duration;
838 int ret;
839 int i;
840
841 graph_ret = &ret_entry->ret;
842 call = &entry->graph_ent;
843 duration = graph_ret->rettime - graph_ret->calltime;
844
845 if (data) {
846 struct fgraph_cpu_data *cpu_data;
847 int cpu = iter->cpu;
848
849 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
850
851 /*
852 * Comments display at + 1 to depth. Since
853 * this is a leaf function, keep the comments
854 * equal to this depth.
855 */
856 cpu_data->depth = call->depth - 1;
857
858 /* No need to keep this function around for this depth */
859 if (call->depth < FTRACE_RETFUNC_DEPTH)
860 cpu_data->enter_funcs[call->depth] = 0;
861 }
862
863 /* Overhead and duration */
864 ret = print_graph_duration(duration, s, flags);
865 if (ret == TRACE_TYPE_PARTIAL_LINE)
866 return TRACE_TYPE_PARTIAL_LINE;
867
868 /* Function */
869 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
870 ret = trace_seq_putc(s, ' ');
871 if (!ret)
872 return TRACE_TYPE_PARTIAL_LINE;
873 }
874
875 ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
876 if (!ret)
877 return TRACE_TYPE_PARTIAL_LINE;
878
879 return TRACE_TYPE_HANDLED;
880 }
881
882 static enum print_line_t
883 print_graph_entry_nested(struct trace_iterator *iter,
884 struct ftrace_graph_ent_entry *entry,
885 struct trace_seq *s, int cpu, u32 flags)
886 {
887 struct ftrace_graph_ent *call = &entry->graph_ent;
888 struct fgraph_data *data = iter->private;
889 int ret;
890 int i;
891
892 if (data) {
893 struct fgraph_cpu_data *cpu_data;
894 int cpu = iter->cpu;
895
896 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
897 cpu_data->depth = call->depth;
898
899 /* Save this function pointer to see if the exit matches */
900 if (call->depth < FTRACE_RETFUNC_DEPTH)
901 cpu_data->enter_funcs[call->depth] = call->func;
902 }
903
904 /* No time */
905 ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
906 if (ret != TRACE_TYPE_HANDLED)
907 return ret;
908
909 /* Function */
910 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
911 ret = trace_seq_putc(s, ' ');
912 if (!ret)
913 return TRACE_TYPE_PARTIAL_LINE;
914 }
915
916 ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
917 if (!ret)
918 return TRACE_TYPE_PARTIAL_LINE;
919
920 /*
921 * we already consumed the current entry to check the next one
922 * and see if this is a leaf.
923 */
924 return TRACE_TYPE_NO_CONSUME;
925 }
926
927 static enum print_line_t
928 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
929 int type, unsigned long addr, u32 flags)
930 {
931 struct fgraph_data *data = iter->private;
932 struct trace_entry *ent = iter->ent;
933 int cpu = iter->cpu;
934 int ret;
935
936 /* Pid */
937 if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
938 return TRACE_TYPE_PARTIAL_LINE;
939
940 if (type) {
941 /* Interrupt */
942 ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
943 if (ret == TRACE_TYPE_PARTIAL_LINE)
944 return TRACE_TYPE_PARTIAL_LINE;
945 }
946
947 if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
948 return 0;
949
950 /* Absolute time */
951 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
952 ret = print_graph_abs_time(iter->ts, s);
953 if (!ret)
954 return TRACE_TYPE_PARTIAL_LINE;
955 }
956
957 /* Cpu */
958 if (flags & TRACE_GRAPH_PRINT_CPU) {
959 ret = print_graph_cpu(s, cpu);
960 if (ret == TRACE_TYPE_PARTIAL_LINE)
961 return TRACE_TYPE_PARTIAL_LINE;
962 }
963
964 /* Proc */
965 if (flags & TRACE_GRAPH_PRINT_PROC) {
966 ret = print_graph_proc(s, ent->pid);
967 if (ret == TRACE_TYPE_PARTIAL_LINE)
968 return TRACE_TYPE_PARTIAL_LINE;
969
970 ret = trace_seq_puts(s, " | ");
971 if (!ret)
972 return TRACE_TYPE_PARTIAL_LINE;
973 }
974
975 /* Latency format */
976 if (trace_flags & TRACE_ITER_LATENCY_FMT) {
977 ret = print_graph_lat_fmt(s, ent);
978 if (ret == TRACE_TYPE_PARTIAL_LINE)
979 return TRACE_TYPE_PARTIAL_LINE;
980 }
981
982 return 0;
983 }
984
985 /*
986 * Entry check for irq code
987 *
988 * returns 1 if
989 * - we are inside irq code
990 * - we just entered irq code
991 *
992 * retunns 0 if
993 * - funcgraph-interrupts option is set
994 * - we are not inside irq code
995 */
996 static int
997 check_irq_entry(struct trace_iterator *iter, u32 flags,
998 unsigned long addr, int depth)
999 {
1000 int cpu = iter->cpu;
1001 int *depth_irq;
1002 struct fgraph_data *data = iter->private;
1003
1004 /*
1005 * If we are either displaying irqs, or we got called as
1006 * a graph event and private data does not exist,
1007 * then we bypass the irq check.
1008 */
1009 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
1010 (!data))
1011 return 0;
1012
1013 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1014
1015 /*
1016 * We are inside the irq code
1017 */
1018 if (*depth_irq >= 0)
1019 return 1;
1020
1021 if ((addr < (unsigned long)__irqentry_text_start) ||
1022 (addr >= (unsigned long)__irqentry_text_end))
1023 return 0;
1024
1025 /*
1026 * We are entering irq code.
1027 */
1028 *depth_irq = depth;
1029 return 1;
1030 }
1031
1032 /*
1033 * Return check for irq code
1034 *
1035 * returns 1 if
1036 * - we are inside irq code
1037 * - we just left irq code
1038 *
1039 * returns 0 if
1040 * - funcgraph-interrupts option is set
1041 * - we are not inside irq code
1042 */
1043 static int
1044 check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
1045 {
1046 int cpu = iter->cpu;
1047 int *depth_irq;
1048 struct fgraph_data *data = iter->private;
1049
1050 /*
1051 * If we are either displaying irqs, or we got called as
1052 * a graph event and private data does not exist,
1053 * then we bypass the irq check.
1054 */
1055 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
1056 (!data))
1057 return 0;
1058
1059 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1060
1061 /*
1062 * We are not inside the irq code.
1063 */
1064 if (*depth_irq == -1)
1065 return 0;
1066
1067 /*
1068 * We are inside the irq code, and this is returning entry.
1069 * Let's not trace it and clear the entry depth, since
1070 * we are out of irq code.
1071 *
1072 * This condition ensures that we 'leave the irq code' once
1073 * we are out of the entry depth. Thus protecting us from
1074 * the RETURN entry loss.
1075 */
1076 if (*depth_irq >= depth) {
1077 *depth_irq = -1;
1078 return 1;
1079 }
1080
1081 /*
1082 * We are inside the irq code, and this is not the entry.
1083 */
1084 return 1;
1085 }
1086
1087 static enum print_line_t
1088 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
1089 struct trace_iterator *iter, u32 flags)
1090 {
1091 struct fgraph_data *data = iter->private;
1092 struct ftrace_graph_ent *call = &field->graph_ent;
1093 struct ftrace_graph_ret_entry *leaf_ret;
1094 static enum print_line_t ret;
1095 int cpu = iter->cpu;
1096
1097 if (check_irq_entry(iter, flags, call->func, call->depth))
1098 return TRACE_TYPE_HANDLED;
1099
1100 if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
1101 return TRACE_TYPE_PARTIAL_LINE;
1102
1103 leaf_ret = get_return_for_leaf(iter, field);
1104 if (leaf_ret)
1105 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
1106 else
1107 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
1108
1109 if (data) {
1110 /*
1111 * If we failed to write our output, then we need to make
1112 * note of it. Because we already consumed our entry.
1113 */
1114 if (s->full) {
1115 data->failed = 1;
1116 data->cpu = cpu;
1117 } else
1118 data->failed = 0;
1119 }
1120
1121 return ret;
1122 }
1123
1124 static enum print_line_t
1125 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
1126 struct trace_entry *ent, struct trace_iterator *iter,
1127 u32 flags)
1128 {
1129 unsigned long long duration = trace->rettime - trace->calltime;
1130 struct fgraph_data *data = iter->private;
1131 pid_t pid = ent->pid;
1132 int cpu = iter->cpu;
1133 int func_match = 1;
1134 int ret;
1135 int i;
1136
1137 if (check_irq_return(iter, flags, trace->depth))
1138 return TRACE_TYPE_HANDLED;
1139
1140 if (data) {
1141 struct fgraph_cpu_data *cpu_data;
1142 int cpu = iter->cpu;
1143
1144 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1145
1146 /*
1147 * Comments display at + 1 to depth. This is the
1148 * return from a function, we now want the comments
1149 * to display at the same level of the bracket.
1150 */
1151 cpu_data->depth = trace->depth - 1;
1152
1153 if (trace->depth < FTRACE_RETFUNC_DEPTH) {
1154 if (cpu_data->enter_funcs[trace->depth] != trace->func)
1155 func_match = 0;
1156 cpu_data->enter_funcs[trace->depth] = 0;
1157 }
1158 }
1159
1160 if (print_graph_prologue(iter, s, 0, 0, flags))
1161 return TRACE_TYPE_PARTIAL_LINE;
1162
1163 /* Overhead and duration */
1164 ret = print_graph_duration(duration, s, flags);
1165 if (ret == TRACE_TYPE_PARTIAL_LINE)
1166 return TRACE_TYPE_PARTIAL_LINE;
1167
1168 /* Closing brace */
1169 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
1170 ret = trace_seq_putc(s, ' ');
1171 if (!ret)
1172 return TRACE_TYPE_PARTIAL_LINE;
1173 }
1174
1175 /*
1176 * If the return function does not have a matching entry,
1177 * then the entry was lost. Instead of just printing
1178 * the '}' and letting the user guess what function this
1179 * belongs to, write out the function name.
1180 */
1181 if (func_match) {
1182 ret = trace_seq_puts(s, "}\n");
1183 if (!ret)
1184 return TRACE_TYPE_PARTIAL_LINE;
1185 } else {
1186 ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
1187 if (!ret)
1188 return TRACE_TYPE_PARTIAL_LINE;
1189 }
1190
1191 /* Overrun */
1192 if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
1193 ret = trace_seq_printf(s, " (Overruns: %lu)\n",
1194 trace->overrun);
1195 if (!ret)
1196 return TRACE_TYPE_PARTIAL_LINE;
1197 }
1198
1199 ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
1200 cpu, pid, flags);
1201 if (ret == TRACE_TYPE_PARTIAL_LINE)
1202 return TRACE_TYPE_PARTIAL_LINE;
1203
1204 return TRACE_TYPE_HANDLED;
1205 }
1206
1207 static enum print_line_t
1208 print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
1209 struct trace_iterator *iter, u32 flags)
1210 {
1211 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1212 struct fgraph_data *data = iter->private;
1213 struct trace_event *event;
1214 int depth = 0;
1215 int ret;
1216 int i;
1217
1218 if (data)
1219 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
1220
1221 if (print_graph_prologue(iter, s, 0, 0, flags))
1222 return TRACE_TYPE_PARTIAL_LINE;
1223
1224 /* No time */
1225 ret = print_graph_duration(0, s, flags | FLAGS_FILL_FULL);
1226 if (ret != TRACE_TYPE_HANDLED)
1227 return ret;
1228
1229 /* Indentation */
1230 if (depth > 0)
1231 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
1232 ret = trace_seq_putc(s, ' ');
1233 if (!ret)
1234 return TRACE_TYPE_PARTIAL_LINE;
1235 }
1236
1237 /* The comment */
1238 ret = trace_seq_puts(s, "/* ");
1239 if (!ret)
1240 return TRACE_TYPE_PARTIAL_LINE;
1241
1242 switch (iter->ent->type) {
1243 case TRACE_BPRINT:
1244 ret = trace_print_bprintk_msg_only(iter);
1245 if (ret != TRACE_TYPE_HANDLED)
1246 return ret;
1247 break;
1248 case TRACE_PRINT:
1249 ret = trace_print_printk_msg_only(iter);
1250 if (ret != TRACE_TYPE_HANDLED)
1251 return ret;
1252 break;
1253 default:
1254 event = ftrace_find_event(ent->type);
1255 if (!event)
1256 return TRACE_TYPE_UNHANDLED;
1257
1258 ret = event->funcs->trace(iter, sym_flags, event);
1259 if (ret != TRACE_TYPE_HANDLED)
1260 return ret;
1261 }
1262
1263 /* Strip ending newline */
1264 if (s->buffer[s->len - 1] == '\n') {
1265 s->buffer[s->len - 1] = '\0';
1266 s->len--;
1267 }
1268
1269 ret = trace_seq_puts(s, " */\n");
1270 if (!ret)
1271 return TRACE_TYPE_PARTIAL_LINE;
1272
1273 return TRACE_TYPE_HANDLED;
1274 }
1275
1276
1277 enum print_line_t
1278 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1279 {
1280 struct ftrace_graph_ent_entry *field;
1281 struct fgraph_data *data = iter->private;
1282 struct trace_entry *entry = iter->ent;
1283 struct trace_seq *s = &iter->seq;
1284 int cpu = iter->cpu;
1285 int ret;
1286
1287 if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1288 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1289 return TRACE_TYPE_HANDLED;
1290 }
1291
1292 /*
1293 * If the last output failed, there's a possibility we need
1294 * to print out the missing entry which would never go out.
1295 */
1296 if (data && data->failed) {
1297 field = &data->ent;
1298 iter->cpu = data->cpu;
1299 ret = print_graph_entry(field, s, iter, flags);
1300 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1301 per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1302 ret = TRACE_TYPE_NO_CONSUME;
1303 }
1304 iter->cpu = cpu;
1305 return ret;
1306 }
1307
1308 switch (entry->type) {
1309 case TRACE_GRAPH_ENT: {
1310 /*
1311 * print_graph_entry() may consume the current event,
1312 * thus @field may become invalid, so we need to save it.
1313 * sizeof(struct ftrace_graph_ent_entry) is very small,
1314 * it can be safely saved at the stack.
1315 */
1316 struct ftrace_graph_ent_entry saved;
1317 trace_assign_type(field, entry);
1318 saved = *field;
1319 return print_graph_entry(&saved, s, iter, flags);
1320 }
1321 case TRACE_GRAPH_RET: {
1322 struct ftrace_graph_ret_entry *field;
1323 trace_assign_type(field, entry);
1324 return print_graph_return(&field->ret, s, entry, iter, flags);
1325 }
1326 case TRACE_STACK:
1327 case TRACE_FN:
1328 /* dont trace stack and functions as comments */
1329 return TRACE_TYPE_UNHANDLED;
1330
1331 default:
1332 return print_graph_comment(s, entry, iter, flags);
1333 }
1334
1335 return TRACE_TYPE_HANDLED;
1336 }
1337
1338 static enum print_line_t
1339 print_graph_function(struct trace_iterator *iter)
1340 {
1341 return print_graph_function_flags(iter, tracer_flags.val);
1342 }
1343
1344 static enum print_line_t
1345 print_graph_function_event(struct trace_iterator *iter, int flags,
1346 struct trace_event *event)
1347 {
1348 return print_graph_function(iter);
1349 }
1350
1351 static void print_lat_header(struct seq_file *s, u32 flags)
1352 {
1353 static const char spaces[] = " " /* 16 spaces */
1354 " " /* 4 spaces */
1355 " "; /* 17 spaces */
1356 int size = 0;
1357
1358 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1359 size += 16;
1360 if (flags & TRACE_GRAPH_PRINT_CPU)
1361 size += 4;
1362 if (flags & TRACE_GRAPH_PRINT_PROC)
1363 size += 17;
1364
1365 seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces);
1366 seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
1367 seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1368 seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
1369 seq_printf(s, "#%.*s||| / \n", size, spaces);
1370 }
1371
1372 static void __print_graph_headers_flags(struct seq_file *s, u32 flags)
1373 {
1374 int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
1375
1376 if (lat)
1377 print_lat_header(s, flags);
1378
1379 /* 1st line */
1380 seq_printf(s, "#");
1381 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1382 seq_printf(s, " TIME ");
1383 if (flags & TRACE_GRAPH_PRINT_CPU)
1384 seq_printf(s, " CPU");
1385 if (flags & TRACE_GRAPH_PRINT_PROC)
1386 seq_printf(s, " TASK/PID ");
1387 if (lat)
1388 seq_printf(s, "||||");
1389 if (flags & TRACE_GRAPH_PRINT_DURATION)
1390 seq_printf(s, " DURATION ");
1391 seq_printf(s, " FUNCTION CALLS\n");
1392
1393 /* 2nd line */
1394 seq_printf(s, "#");
1395 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1396 seq_printf(s, " | ");
1397 if (flags & TRACE_GRAPH_PRINT_CPU)
1398 seq_printf(s, " | ");
1399 if (flags & TRACE_GRAPH_PRINT_PROC)
1400 seq_printf(s, " | | ");
1401 if (lat)
1402 seq_printf(s, "||||");
1403 if (flags & TRACE_GRAPH_PRINT_DURATION)
1404 seq_printf(s, " | | ");
1405 seq_printf(s, " | | | |\n");
1406 }
1407
1408 void print_graph_headers(struct seq_file *s)
1409 {
1410 print_graph_headers_flags(s, tracer_flags.val);
1411 }
1412
1413 void print_graph_headers_flags(struct seq_file *s, u32 flags)
1414 {
1415 struct trace_iterator *iter = s->private;
1416
1417 if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
1418 return;
1419
1420 if (trace_flags & TRACE_ITER_LATENCY_FMT) {
1421 /* print nothing if the buffers are empty */
1422 if (trace_empty(iter))
1423 return;
1424
1425 print_trace_header(s, iter);
1426 }
1427
1428 __print_graph_headers_flags(s, flags);
1429 }
1430
1431 void graph_trace_open(struct trace_iterator *iter)
1432 {
1433 /* pid and depth on the last trace processed */
1434 struct fgraph_data *data;
1435 int cpu;
1436
1437 iter->private = NULL;
1438
1439 data = kzalloc(sizeof(*data), GFP_KERNEL);
1440 if (!data)
1441 goto out_err;
1442
1443 data->cpu_data = alloc_percpu(struct fgraph_cpu_data);
1444 if (!data->cpu_data)
1445 goto out_err_free;
1446
1447 for_each_possible_cpu(cpu) {
1448 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1449 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1450 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1451 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1452
1453 *pid = -1;
1454 *depth = 0;
1455 *ignore = 0;
1456 *depth_irq = -1;
1457 }
1458
1459 iter->private = data;
1460
1461 return;
1462
1463 out_err_free:
1464 kfree(data);
1465 out_err:
1466 pr_warning("function graph tracer: not enough memory\n");
1467 }
1468
1469 void graph_trace_close(struct trace_iterator *iter)
1470 {
1471 struct fgraph_data *data = iter->private;
1472
1473 if (data) {
1474 free_percpu(data->cpu_data);
1475 kfree(data);
1476 }
1477 }
1478
1479 static int func_graph_set_flag(u32 old_flags, u32 bit, int set)
1480 {
1481 if (bit == TRACE_GRAPH_PRINT_IRQS)
1482 ftrace_graph_skip_irqs = !set;
1483
1484 return 0;
1485 }
1486
1487 static struct trace_event_functions graph_functions = {
1488 .trace = print_graph_function_event,
1489 };
1490
1491 static struct trace_event graph_trace_entry_event = {
1492 .type = TRACE_GRAPH_ENT,
1493 .funcs = &graph_functions,
1494 };
1495
1496 static struct trace_event graph_trace_ret_event = {
1497 .type = TRACE_GRAPH_RET,
1498 .funcs = &graph_functions
1499 };
1500
1501 static struct tracer graph_trace __tracer_data = {
1502 .name = "function_graph",
1503 .open = graph_trace_open,
1504 .pipe_open = graph_trace_open,
1505 .close = graph_trace_close,
1506 .pipe_close = graph_trace_close,
1507 .wait_pipe = poll_wait_pipe,
1508 .init = graph_trace_init,
1509 .reset = graph_trace_reset,
1510 .print_line = print_graph_function,
1511 .print_header = print_graph_headers,
1512 .flags = &tracer_flags,
1513 .set_flag = func_graph_set_flag,
1514 #ifdef CONFIG_FTRACE_SELFTEST
1515 .selftest = trace_selftest_startup_function_graph,
1516 #endif
1517 };
1518
1519
1520 static ssize_t
1521 graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
1522 loff_t *ppos)
1523 {
1524 unsigned long val;
1525 int ret;
1526
1527 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1528 if (ret)
1529 return ret;
1530
1531 max_depth = val;
1532
1533 *ppos += cnt;
1534
1535 return cnt;
1536 }
1537
1538 static ssize_t
1539 graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
1540 loff_t *ppos)
1541 {
1542 char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/
1543 int n;
1544
1545 n = sprintf(buf, "%d\n", max_depth);
1546
1547 return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
1548 }
1549
1550 static const struct file_operations graph_depth_fops = {
1551 .open = tracing_open_generic,
1552 .write = graph_depth_write,
1553 .read = graph_depth_read,
1554 .llseek = generic_file_llseek,
1555 };
1556
1557 static __init int init_graph_debugfs(void)
1558 {
1559 struct dentry *d_tracer;
1560
1561 d_tracer = tracing_init_dentry();
1562 if (!d_tracer)
1563 return 0;
1564
1565 trace_create_file("max_graph_depth", 0644, d_tracer,
1566 NULL, &graph_depth_fops);
1567
1568 return 0;
1569 }
1570 fs_initcall(init_graph_debugfs);
1571
1572 static __init int init_graph_trace(void)
1573 {
1574 max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
1575
1576 if (!register_ftrace_event(&graph_trace_entry_event)) {
1577 pr_warning("Warning: could not register graph trace events\n");
1578 return 1;
1579 }
1580
1581 if (!register_ftrace_event(&graph_trace_ret_event)) {
1582 pr_warning("Warning: could not register graph trace events\n");
1583 return 1;
1584 }
1585
1586 return register_tracer(&graph_trace);
1587 }
1588
1589 core_initcall(init_graph_trace);
Linux with added FPC-III support