projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'bug-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs...
[GitHub/mt8127/android_kernel_alcatel_ttab.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 struct fgraph_cpu_data {
19 pid_t last_pid;
20 int depth;
21 int ignore;
22 unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH];
23 };
24
25 struct fgraph_data {
26 struct fgraph_cpu_data *cpu_data;
27
28 /* Place to preserve last processed entry. */
29 struct ftrace_graph_ent_entry ent;
30 struct ftrace_graph_ret_entry ret;
31 int failed;
32 int cpu;
33 };
34
35 #define TRACE_GRAPH_INDENT 2
36
37 /* Flag options */
38 #define TRACE_GRAPH_PRINT_OVERRUN 0x1
39 #define TRACE_GRAPH_PRINT_CPU 0x2
40 #define TRACE_GRAPH_PRINT_OVERHEAD 0x4
41 #define TRACE_GRAPH_PRINT_PROC 0x8
42 #define TRACE_GRAPH_PRINT_DURATION 0x10
43 #define TRACE_GRAPH_PRINT_ABS_TIME 0x20
44
45 static struct tracer_opt trace_opts[] = {
46 /* Display overruns? (for self-debug purpose) */
47 { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
48 /* Display CPU ? */
49 { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
50 /* Display Overhead ? */
51 { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
52 /* Display proc name/pid */
53 { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
54 /* Display duration of execution */
55 { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
56 /* Display absolute time of an entry */
57 { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
58 { } /* Empty entry */
59 };
60
61 static struct tracer_flags tracer_flags = {
62 /* Don't display overruns and proc by default */
63 .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
64 TRACE_GRAPH_PRINT_DURATION,
65 .opts = trace_opts
66 };
67
68 static struct trace_array *graph_array;
69
70
71 /* Add a function return address to the trace stack on thread info.*/
72 int
73 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
74 unsigned long frame_pointer)
75 {
76 unsigned long long calltime;
77 int index;
78
79 if (!current->ret_stack)
80 return -EBUSY;
81
82 /*
83 * We must make sure the ret_stack is tested before we read
84 * anything else.
85 */
86 smp_rmb();
87
88 /* The return trace stack is full */
89 if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
90 atomic_inc(&current->trace_overrun);
91 return -EBUSY;
92 }
93
94 calltime = trace_clock_local();
95
96 index = ++current->curr_ret_stack;
97 barrier();
98 current->ret_stack[index].ret = ret;
99 current->ret_stack[index].func = func;
100 current->ret_stack[index].calltime = calltime;
101 current->ret_stack[index].subtime = 0;
102 current->ret_stack[index].fp = frame_pointer;
103 *depth = index;
104
105 return 0;
106 }
107
108 /* Retrieve a function return address to the trace stack on thread info.*/
109 static void
110 ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
111 unsigned long frame_pointer)
112 {
113 int index;
114
115 index = current->curr_ret_stack;
116
117 if (unlikely(index < 0)) {
118 ftrace_graph_stop();
119 WARN_ON(1);
120 /* Might as well panic, otherwise we have no where to go */
121 *ret = (unsigned long)panic;
122 return;
123 }
124
125 #ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
126 /*
127 * The arch may choose to record the frame pointer used
128 * and check it here to make sure that it is what we expect it
129 * to be. If gcc does not set the place holder of the return
130 * address in the frame pointer, and does a copy instead, then
131 * the function graph trace will fail. This test detects this
132 * case.
133 *
134 * Currently, x86_32 with optimize for size (-Os) makes the latest
135 * gcc do the above.
136 */
137 if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
138 ftrace_graph_stop();
139 WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
140 " from func %ps return to %lx\n",
141 current->ret_stack[index].fp,
142 frame_pointer,
143 (void *)current->ret_stack[index].func,
144 current->ret_stack[index].ret);
145 *ret = (unsigned long)panic;
146 return;
147 }
148 #endif
149
150 *ret = current->ret_stack[index].ret;
151 trace->func = current->ret_stack[index].func;
152 trace->calltime = current->ret_stack[index].calltime;
153 trace->overrun = atomic_read(&current->trace_overrun);
154 trace->depth = index;
155 }
156
157 /*
158 * Send the trace to the ring-buffer.
159 * @return the original return address.
160 */
161 unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
162 {
163 struct ftrace_graph_ret trace;
164 unsigned long ret;
165
166 ftrace_pop_return_trace(&trace, &ret, frame_pointer);
167 trace.rettime = trace_clock_local();
168 ftrace_graph_return(&trace);
169 barrier();
170 current->curr_ret_stack--;
171
172 if (unlikely(!ret)) {
173 ftrace_graph_stop();
174 WARN_ON(1);
175 /* Might as well panic. What else to do? */
176 ret = (unsigned long)panic;
177 }
178
179 return ret;
180 }
181
182 int __trace_graph_entry(struct trace_array *tr,
183 struct ftrace_graph_ent *trace,
184 unsigned long flags,
185 int pc)
186 {
187 struct ftrace_event_call *call = &event_funcgraph_entry;
188 struct ring_buffer_event *event;
189 struct ring_buffer *buffer = tr->buffer;
190 struct ftrace_graph_ent_entry *entry;
191
192 if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
193 return 0;
194
195 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
196 sizeof(*entry), flags, pc);
197 if (!event)
198 return 0;
199 entry = ring_buffer_event_data(event);
200 entry->graph_ent = *trace;
201 if (!filter_current_check_discard(buffer, call, entry, event))
202 ring_buffer_unlock_commit(buffer, event);
203
204 return 1;
205 }
206
207 int trace_graph_entry(struct ftrace_graph_ent *trace)
208 {
209 struct trace_array *tr = graph_array;
210 struct trace_array_cpu *data;
211 unsigned long flags;
212 long disabled;
213 int ret;
214 int cpu;
215 int pc;
216
217 if (!ftrace_trace_task(current))
218 return 0;
219
220 /* trace it when it is-nested-in or is a function enabled. */
221 if (!(trace->depth || ftrace_graph_addr(trace->func)))
222 return 0;
223
224 local_irq_save(flags);
225 cpu = raw_smp_processor_id();
226 data = tr->data[cpu];
227 disabled = atomic_inc_return(&data->disabled);
228 if (likely(disabled == 1)) {
229 pc = preempt_count();
230 ret = __trace_graph_entry(tr, trace, flags, pc);
231 } else {
232 ret = 0;
233 }
234
235 atomic_dec(&data->disabled);
236 local_irq_restore(flags);
237
238 return ret;
239 }
240
241 int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
242 {
243 if (tracing_thresh)
244 return 1;
245 else
246 return trace_graph_entry(trace);
247 }
248
249 void __trace_graph_return(struct trace_array *tr,
250 struct ftrace_graph_ret *trace,
251 unsigned long flags,
252 int pc)
253 {
254 struct ftrace_event_call *call = &event_funcgraph_exit;
255 struct ring_buffer_event *event;
256 struct ring_buffer *buffer = tr->buffer;
257 struct ftrace_graph_ret_entry *entry;
258
259 if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
260 return;
261
262 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
263 sizeof(*entry), flags, pc);
264 if (!event)
265 return;
266 entry = ring_buffer_event_data(event);
267 entry->ret = *trace;
268 if (!filter_current_check_discard(buffer, call, entry, event))
269 ring_buffer_unlock_commit(buffer, event);
270 }
271
272 void trace_graph_return(struct ftrace_graph_ret *trace)
273 {
274 struct trace_array *tr = graph_array;
275 struct trace_array_cpu *data;
276 unsigned long flags;
277 long disabled;
278 int cpu;
279 int pc;
280
281 local_irq_save(flags);
282 cpu = raw_smp_processor_id();
283 data = tr->data[cpu];
284 disabled = atomic_inc_return(&data->disabled);
285 if (likely(disabled == 1)) {
286 pc = preempt_count();
287 __trace_graph_return(tr, trace, flags, pc);
288 }
289 atomic_dec(&data->disabled);
290 local_irq_restore(flags);
291 }
292
293 void set_graph_array(struct trace_array *tr)
294 {
295 graph_array = tr;
296
297 /* Make graph_array visible before we start tracing */
298
299 smp_mb();
300 }
301
302 void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
303 {
304 if (tracing_thresh &&
305 (trace->rettime - trace->calltime < tracing_thresh))
306 return;
307 else
308 trace_graph_return(trace);
309 }
310
311 static int graph_trace_init(struct trace_array *tr)
312 {
313 int ret;
314
315 set_graph_array(tr);
316 if (tracing_thresh)
317 ret = register_ftrace_graph(&trace_graph_thresh_return,
318 &trace_graph_thresh_entry);
319 else
320 ret = register_ftrace_graph(&trace_graph_return,
321 &trace_graph_entry);
322 if (ret)
323 return ret;
324 tracing_start_cmdline_record();
325
326 return 0;
327 }
328
329 static void graph_trace_reset(struct trace_array *tr)
330 {
331 tracing_stop_cmdline_record();
332 unregister_ftrace_graph();
333 }
334
335 static int max_bytes_for_cpu;
336
337 static enum print_line_t
338 print_graph_cpu(struct trace_seq *s, int cpu)
339 {
340 int ret;
341
342 /*
343 * Start with a space character - to make it stand out
344 * to the right a bit when trace output is pasted into
345 * email:
346 */
347 ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
348 if (!ret)
349 return TRACE_TYPE_PARTIAL_LINE;
350
351 return TRACE_TYPE_HANDLED;
352 }
353
354 #define TRACE_GRAPH_PROCINFO_LENGTH 14
355
356 static enum print_line_t
357 print_graph_proc(struct trace_seq *s, pid_t pid)
358 {
359 char comm[TASK_COMM_LEN];
360 /* sign + log10(MAX_INT) + '\0' */
361 char pid_str[11];
362 int spaces = 0;
363 int ret;
364 int len;
365 int i;
366
367 trace_find_cmdline(pid, comm);
368 comm[7] = '\0';
369 sprintf(pid_str, "%d", pid);
370
371 /* 1 stands for the "-" character */
372 len = strlen(comm) + strlen(pid_str) + 1;
373
374 if (len < TRACE_GRAPH_PROCINFO_LENGTH)
375 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
376
377 /* First spaces to align center */
378 for (i = 0; i < spaces / 2; i++) {
379 ret = trace_seq_printf(s, " ");
380 if (!ret)
381 return TRACE_TYPE_PARTIAL_LINE;
382 }
383
384 ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
385 if (!ret)
386 return TRACE_TYPE_PARTIAL_LINE;
387
388 /* Last spaces to align center */
389 for (i = 0; i < spaces - (spaces / 2); i++) {
390 ret = trace_seq_printf(s, " ");
391 if (!ret)
392 return TRACE_TYPE_PARTIAL_LINE;
393 }
394 return TRACE_TYPE_HANDLED;
395 }
396
397
398 static enum print_line_t
399 print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
400 {
401 if (!trace_seq_putc(s, ' '))
402 return 0;
403
404 return trace_print_lat_fmt(s, entry);
405 }
406
407 /* If the pid changed since the last trace, output this event */
408 static enum print_line_t
409 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
410 {
411 pid_t prev_pid;
412 pid_t *last_pid;
413 int ret;
414
415 if (!data)
416 return TRACE_TYPE_HANDLED;
417
418 last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
419
420 if (*last_pid == pid)
421 return TRACE_TYPE_HANDLED;
422
423 prev_pid = *last_pid;
424 *last_pid = pid;
425
426 if (prev_pid == -1)
427 return TRACE_TYPE_HANDLED;
428 /*
429 * Context-switch trace line:
430
431 ------------------------------------------
432 | 1) migration/0--1 => sshd-1755
433 ------------------------------------------
434
435 */
436 ret = trace_seq_printf(s,
437 " ------------------------------------------\n");
438 if (!ret)
439 return TRACE_TYPE_PARTIAL_LINE;
440
441 ret = print_graph_cpu(s, cpu);
442 if (ret == TRACE_TYPE_PARTIAL_LINE)
443 return TRACE_TYPE_PARTIAL_LINE;
444
445 ret = print_graph_proc(s, prev_pid);
446 if (ret == TRACE_TYPE_PARTIAL_LINE)
447 return TRACE_TYPE_PARTIAL_LINE;
448
449 ret = trace_seq_printf(s, " => ");
450 if (!ret)
451 return TRACE_TYPE_PARTIAL_LINE;
452
453 ret = print_graph_proc(s, pid);
454 if (ret == TRACE_TYPE_PARTIAL_LINE)
455 return TRACE_TYPE_PARTIAL_LINE;
456
457 ret = trace_seq_printf(s,
458 "\n ------------------------------------------\n\n");
459 if (!ret)
460 return TRACE_TYPE_PARTIAL_LINE;
461
462 return TRACE_TYPE_HANDLED;
463 }
464
465 static struct ftrace_graph_ret_entry *
466 get_return_for_leaf(struct trace_iterator *iter,
467 struct ftrace_graph_ent_entry *curr)
468 {
469 struct fgraph_data *data = iter->private;
470 struct ring_buffer_iter *ring_iter = NULL;
471 struct ring_buffer_event *event;
472 struct ftrace_graph_ret_entry *next;
473
474 /*
475 * If the previous output failed to write to the seq buffer,
476 * then we just reuse the data from before.
477 */
478 if (data && data->failed) {
479 curr = &data->ent;
480 next = &data->ret;
481 } else {
482
483 ring_iter = iter->buffer_iter[iter->cpu];
484
485 /* First peek to compare current entry and the next one */
486 if (ring_iter)
487 event = ring_buffer_iter_peek(ring_iter, NULL);
488 else {
489 /*
490 * We need to consume the current entry to see
491 * the next one.
492 */
493 ring_buffer_consume(iter->tr->buffer, iter->cpu,
494 NULL, NULL);
495 event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
496 NULL, NULL);
497 }
498
499 if (!event)
500 return NULL;
501
502 next = ring_buffer_event_data(event);
503
504 if (data) {
505 /*
506 * Save current and next entries for later reference
507 * if the output fails.
508 */
509 data->ent = *curr;
510 /*
511 * If the next event is not a return type, then
512 * we only care about what type it is. Otherwise we can
513 * safely copy the entire event.
514 */
515 if (next->ent.type == TRACE_GRAPH_RET)
516 data->ret = *next;
517 else
518 data->ret.ent.type = next->ent.type;
519 }
520 }
521
522 if (next->ent.type != TRACE_GRAPH_RET)
523 return NULL;
524
525 if (curr->ent.pid != next->ent.pid ||
526 curr->graph_ent.func != next->ret.func)
527 return NULL;
528
529 /* this is a leaf, now advance the iterator */
530 if (ring_iter)
531 ring_buffer_read(ring_iter, NULL);
532
533 return next;
534 }
535
536 /* Signal a overhead of time execution to the output */
537 static int
538 print_graph_overhead(unsigned long long duration, struct trace_seq *s,
539 u32 flags)
540 {
541 /* If duration disappear, we don't need anything */
542 if (!(flags & TRACE_GRAPH_PRINT_DURATION))
543 return 1;
544
545 /* Non nested entry or return */
546 if (duration == -1)
547 return trace_seq_printf(s, " ");
548
549 if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
550 /* Duration exceeded 100 msecs */
551 if (duration > 100000ULL)
552 return trace_seq_printf(s, "! ");
553
554 /* Duration exceeded 10 msecs */
555 if (duration > 10000ULL)
556 return trace_seq_printf(s, "+ ");
557 }
558
559 return trace_seq_printf(s, " ");
560 }
561
562 static int print_graph_abs_time(u64 t, struct trace_seq *s)
563 {
564 unsigned long usecs_rem;
565
566 usecs_rem = do_div(t, NSEC_PER_SEC);
567 usecs_rem /= 1000;
568
569 return trace_seq_printf(s, "%5lu.%06lu | ",
570 (unsigned long)t, usecs_rem);
571 }
572
573 static enum print_line_t
574 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
575 enum trace_type type, int cpu, pid_t pid, u32 flags)
576 {
577 int ret;
578 struct trace_seq *s = &iter->seq;
579
580 if (addr < (unsigned long)__irqentry_text_start ||
581 addr >= (unsigned long)__irqentry_text_end)
582 return TRACE_TYPE_UNHANDLED;
583
584 /* Absolute time */
585 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
586 ret = print_graph_abs_time(iter->ts, s);
587 if (!ret)
588 return TRACE_TYPE_PARTIAL_LINE;
589 }
590
591 /* Cpu */
592 if (flags & TRACE_GRAPH_PRINT_CPU) {
593 ret = print_graph_cpu(s, cpu);
594 if (ret == TRACE_TYPE_PARTIAL_LINE)
595 return TRACE_TYPE_PARTIAL_LINE;
596 }
597
598 /* Proc */
599 if (flags & TRACE_GRAPH_PRINT_PROC) {
600 ret = print_graph_proc(s, pid);
601 if (ret == TRACE_TYPE_PARTIAL_LINE)
602 return TRACE_TYPE_PARTIAL_LINE;
603 ret = trace_seq_printf(s, " | ");
604 if (!ret)
605 return TRACE_TYPE_PARTIAL_LINE;
606 }
607
608 /* No overhead */
609 ret = print_graph_overhead(-1, s, flags);
610 if (!ret)
611 return TRACE_TYPE_PARTIAL_LINE;
612
613 if (type == TRACE_GRAPH_ENT)
614 ret = trace_seq_printf(s, "==========>");
615 else
616 ret = trace_seq_printf(s, "<==========");
617
618 if (!ret)
619 return TRACE_TYPE_PARTIAL_LINE;
620
621 /* Don't close the duration column if haven't one */
622 if (flags & TRACE_GRAPH_PRINT_DURATION)
623 trace_seq_printf(s, " |");
624 ret = trace_seq_printf(s, "\n");
625
626 if (!ret)
627 return TRACE_TYPE_PARTIAL_LINE;
628 return TRACE_TYPE_HANDLED;
629 }
630
631 enum print_line_t
632 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
633 {
634 unsigned long nsecs_rem = do_div(duration, 1000);
635 /* log10(ULONG_MAX) + '\0' */
636 char msecs_str[21];
637 char nsecs_str[5];
638 int ret, len;
639 int i;
640
641 sprintf(msecs_str, "%lu", (unsigned long) duration);
642
643 /* Print msecs */
644 ret = trace_seq_printf(s, "%s", msecs_str);
645 if (!ret)
646 return TRACE_TYPE_PARTIAL_LINE;
647
648 len = strlen(msecs_str);
649
650 /* Print nsecs (we don't want to exceed 7 numbers) */
651 if (len < 7) {
652 snprintf(nsecs_str, min(sizeof(nsecs_str), 8UL - len), "%03lu",
653 nsecs_rem);
654 ret = trace_seq_printf(s, ".%s", nsecs_str);
655 if (!ret)
656 return TRACE_TYPE_PARTIAL_LINE;
657 len += strlen(nsecs_str);
658 }
659
660 ret = trace_seq_printf(s, " us ");
661 if (!ret)
662 return TRACE_TYPE_PARTIAL_LINE;
663
664 /* Print remaining spaces to fit the row's width */
665 for (i = len; i < 7; i++) {
666 ret = trace_seq_printf(s, " ");
667 if (!ret)
668 return TRACE_TYPE_PARTIAL_LINE;
669 }
670 return TRACE_TYPE_HANDLED;
671 }
672
673 static enum print_line_t
674 print_graph_duration(unsigned long long duration, struct trace_seq *s)
675 {
676 int ret;
677
678 ret = trace_print_graph_duration(duration, s);
679 if (ret != TRACE_TYPE_HANDLED)
680 return ret;
681
682 ret = trace_seq_printf(s, "| ");
683 if (!ret)
684 return TRACE_TYPE_PARTIAL_LINE;
685
686 return TRACE_TYPE_HANDLED;
687 }
688
689 /* Case of a leaf function on its call entry */
690 static enum print_line_t
691 print_graph_entry_leaf(struct trace_iterator *iter,
692 struct ftrace_graph_ent_entry *entry,
693 struct ftrace_graph_ret_entry *ret_entry,
694 struct trace_seq *s, u32 flags)
695 {
696 struct fgraph_data *data = iter->private;
697 struct ftrace_graph_ret *graph_ret;
698 struct ftrace_graph_ent *call;
699 unsigned long long duration;
700 int ret;
701 int i;
702
703 graph_ret = &ret_entry->ret;
704 call = &entry->graph_ent;
705 duration = graph_ret->rettime - graph_ret->calltime;
706
707 if (data) {
708 struct fgraph_cpu_data *cpu_data;
709 int cpu = iter->cpu;
710
711 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
712
713 /*
714 * Comments display at + 1 to depth. Since
715 * this is a leaf function, keep the comments
716 * equal to this depth.
717 */
718 cpu_data->depth = call->depth - 1;
719
720 /* No need to keep this function around for this depth */
721 if (call->depth < FTRACE_RETFUNC_DEPTH)
722 cpu_data->enter_funcs[call->depth] = 0;
723 }
724
725 /* Overhead */
726 ret = print_graph_overhead(duration, s, flags);
727 if (!ret)
728 return TRACE_TYPE_PARTIAL_LINE;
729
730 /* Duration */
731 if (flags & TRACE_GRAPH_PRINT_DURATION) {
732 ret = print_graph_duration(duration, s);
733 if (ret == TRACE_TYPE_PARTIAL_LINE)
734 return TRACE_TYPE_PARTIAL_LINE;
735 }
736
737 /* Function */
738 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
739 ret = trace_seq_printf(s, " ");
740 if (!ret)
741 return TRACE_TYPE_PARTIAL_LINE;
742 }
743
744 ret = trace_seq_printf(s, "%ps();\n", (void *)call->func);
745 if (!ret)
746 return TRACE_TYPE_PARTIAL_LINE;
747
748 return TRACE_TYPE_HANDLED;
749 }
750
751 static enum print_line_t
752 print_graph_entry_nested(struct trace_iterator *iter,
753 struct ftrace_graph_ent_entry *entry,
754 struct trace_seq *s, int cpu, u32 flags)
755 {
756 struct ftrace_graph_ent *call = &entry->graph_ent;
757 struct fgraph_data *data = iter->private;
758 int ret;
759 int i;
760
761 if (data) {
762 struct fgraph_cpu_data *cpu_data;
763 int cpu = iter->cpu;
764
765 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
766 cpu_data->depth = call->depth;
767
768 /* Save this function pointer to see if the exit matches */
769 if (call->depth < FTRACE_RETFUNC_DEPTH)
770 cpu_data->enter_funcs[call->depth] = call->func;
771 }
772
773 /* No overhead */
774 ret = print_graph_overhead(-1, s, flags);
775 if (!ret)
776 return TRACE_TYPE_PARTIAL_LINE;
777
778 /* No time */
779 if (flags & TRACE_GRAPH_PRINT_DURATION) {
780 ret = trace_seq_printf(s, " | ");
781 if (!ret)
782 return TRACE_TYPE_PARTIAL_LINE;
783 }
784
785 /* Function */
786 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
787 ret = trace_seq_printf(s, " ");
788 if (!ret)
789 return TRACE_TYPE_PARTIAL_LINE;
790 }
791
792 ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func);
793 if (!ret)
794 return TRACE_TYPE_PARTIAL_LINE;
795
796 /*
797 * we already consumed the current entry to check the next one
798 * and see if this is a leaf.
799 */
800 return TRACE_TYPE_NO_CONSUME;
801 }
802
803 static enum print_line_t
804 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
805 int type, unsigned long addr, u32 flags)
806 {
807 struct fgraph_data *data = iter->private;
808 struct trace_entry *ent = iter->ent;
809 int cpu = iter->cpu;
810 int ret;
811
812 /* Pid */
813 if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE)
814 return TRACE_TYPE_PARTIAL_LINE;
815
816 if (type) {
817 /* Interrupt */
818 ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
819 if (ret == TRACE_TYPE_PARTIAL_LINE)
820 return TRACE_TYPE_PARTIAL_LINE;
821 }
822
823 /* Absolute time */
824 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) {
825 ret = print_graph_abs_time(iter->ts, s);
826 if (!ret)
827 return TRACE_TYPE_PARTIAL_LINE;
828 }
829
830 /* Cpu */
831 if (flags & TRACE_GRAPH_PRINT_CPU) {
832 ret = print_graph_cpu(s, cpu);
833 if (ret == TRACE_TYPE_PARTIAL_LINE)
834 return TRACE_TYPE_PARTIAL_LINE;
835 }
836
837 /* Proc */
838 if (flags & TRACE_GRAPH_PRINT_PROC) {
839 ret = print_graph_proc(s, ent->pid);
840 if (ret == TRACE_TYPE_PARTIAL_LINE)
841 return TRACE_TYPE_PARTIAL_LINE;
842
843 ret = trace_seq_printf(s, " | ");
844 if (!ret)
845 return TRACE_TYPE_PARTIAL_LINE;
846 }
847
848 /* Latency format */
849 if (trace_flags & TRACE_ITER_LATENCY_FMT) {
850 ret = print_graph_lat_fmt(s, ent);
851 if (ret == TRACE_TYPE_PARTIAL_LINE)
852 return TRACE_TYPE_PARTIAL_LINE;
853 }
854
855 return 0;
856 }
857
858 static enum print_line_t
859 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
860 struct trace_iterator *iter, u32 flags)
861 {
862 struct fgraph_data *data = iter->private;
863 struct ftrace_graph_ent *call = &field->graph_ent;
864 struct ftrace_graph_ret_entry *leaf_ret;
865 static enum print_line_t ret;
866 int cpu = iter->cpu;
867
868 if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
869 return TRACE_TYPE_PARTIAL_LINE;
870
871 leaf_ret = get_return_for_leaf(iter, field);
872 if (leaf_ret)
873 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
874 else
875 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
876
877 if (data) {
878 /*
879 * If we failed to write our output, then we need to make
880 * note of it. Because we already consumed our entry.
881 */
882 if (s->full) {
883 data->failed = 1;
884 data->cpu = cpu;
885 } else
886 data->failed = 0;
887 }
888
889 return ret;
890 }
891
892 static enum print_line_t
893 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
894 struct trace_entry *ent, struct trace_iterator *iter,
895 u32 flags)
896 {
897 unsigned long long duration = trace->rettime - trace->calltime;
898 struct fgraph_data *data = iter->private;
899 pid_t pid = ent->pid;
900 int cpu = iter->cpu;
901 int func_match = 1;
902 int ret;
903 int i;
904
905 if (data) {
906 struct fgraph_cpu_data *cpu_data;
907 int cpu = iter->cpu;
908
909 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
910
911 /*
912 * Comments display at + 1 to depth. This is the
913 * return from a function, we now want the comments
914 * to display at the same level of the bracket.
915 */
916 cpu_data->depth = trace->depth - 1;
917
918 if (trace->depth < FTRACE_RETFUNC_DEPTH) {
919 if (cpu_data->enter_funcs[trace->depth] != trace->func)
920 func_match = 0;
921 cpu_data->enter_funcs[trace->depth] = 0;
922 }
923 }
924
925 if (print_graph_prologue(iter, s, 0, 0, flags))
926 return TRACE_TYPE_PARTIAL_LINE;
927
928 /* Overhead */
929 ret = print_graph_overhead(duration, s, flags);
930 if (!ret)
931 return TRACE_TYPE_PARTIAL_LINE;
932
933 /* Duration */
934 if (flags & TRACE_GRAPH_PRINT_DURATION) {
935 ret = print_graph_duration(duration, s);
936 if (ret == TRACE_TYPE_PARTIAL_LINE)
937 return TRACE_TYPE_PARTIAL_LINE;
938 }
939
940 /* Closing brace */
941 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
942 ret = trace_seq_printf(s, " ");
943 if (!ret)
944 return TRACE_TYPE_PARTIAL_LINE;
945 }
946
947 /*
948 * If the return function does not have a matching entry,
949 * then the entry was lost. Instead of just printing
950 * the '}' and letting the user guess what function this
951 * belongs to, write out the function name.
952 */
953 if (func_match) {
954 ret = trace_seq_printf(s, "}\n");
955 if (!ret)
956 return TRACE_TYPE_PARTIAL_LINE;
957 } else {
958 ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
959 if (!ret)
960 return TRACE_TYPE_PARTIAL_LINE;
961 }
962
963 /* Overrun */
964 if (flags & TRACE_GRAPH_PRINT_OVERRUN) {
965 ret = trace_seq_printf(s, " (Overruns: %lu)\n",
966 trace->overrun);
967 if (!ret)
968 return TRACE_TYPE_PARTIAL_LINE;
969 }
970
971 ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
972 cpu, pid, flags);
973 if (ret == TRACE_TYPE_PARTIAL_LINE)
974 return TRACE_TYPE_PARTIAL_LINE;
975
976 return TRACE_TYPE_HANDLED;
977 }
978
979 static enum print_line_t
980 print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
981 struct trace_iterator *iter, u32 flags)
982 {
983 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
984 struct fgraph_data *data = iter->private;
985 struct trace_event *event;
986 int depth = 0;
987 int ret;
988 int i;
989
990 if (data)
991 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
992
993 if (print_graph_prologue(iter, s, 0, 0, flags))
994 return TRACE_TYPE_PARTIAL_LINE;
995
996 /* No overhead */
997 ret = print_graph_overhead(-1, s, flags);
998 if (!ret)
999 return TRACE_TYPE_PARTIAL_LINE;
1000
1001 /* No time */
1002 if (flags & TRACE_GRAPH_PRINT_DURATION) {
1003 ret = trace_seq_printf(s, " | ");
1004 if (!ret)
1005 return TRACE_TYPE_PARTIAL_LINE;
1006 }
1007
1008 /* Indentation */
1009 if (depth > 0)
1010 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) {
1011 ret = trace_seq_printf(s, " ");
1012 if (!ret)
1013 return TRACE_TYPE_PARTIAL_LINE;
1014 }
1015
1016 /* The comment */
1017 ret = trace_seq_printf(s, "/* ");
1018 if (!ret)
1019 return TRACE_TYPE_PARTIAL_LINE;
1020
1021 switch (iter->ent->type) {
1022 case TRACE_BPRINT:
1023 ret = trace_print_bprintk_msg_only(iter);
1024 if (ret != TRACE_TYPE_HANDLED)
1025 return ret;
1026 break;
1027 case TRACE_PRINT:
1028 ret = trace_print_printk_msg_only(iter);
1029 if (ret != TRACE_TYPE_HANDLED)
1030 return ret;
1031 break;
1032 default:
1033 event = ftrace_find_event(ent->type);
1034 if (!event)
1035 return TRACE_TYPE_UNHANDLED;
1036
1037 ret = event->funcs->trace(iter, sym_flags, event);
1038 if (ret != TRACE_TYPE_HANDLED)
1039 return ret;
1040 }
1041
1042 /* Strip ending newline */
1043 if (s->buffer[s->len - 1] == '\n') {
1044 s->buffer[s->len - 1] = '\0';
1045 s->len--;
1046 }
1047
1048 ret = trace_seq_printf(s, " */\n");
1049 if (!ret)
1050 return TRACE_TYPE_PARTIAL_LINE;
1051
1052 return TRACE_TYPE_HANDLED;
1053 }
1054
1055
1056 enum print_line_t
1057 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1058 {
1059 struct ftrace_graph_ent_entry *field;
1060 struct fgraph_data *data = iter->private;
1061 struct trace_entry *entry = iter->ent;
1062 struct trace_seq *s = &iter->seq;
1063 int cpu = iter->cpu;
1064 int ret;
1065
1066 if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1067 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1068 return TRACE_TYPE_HANDLED;
1069 }
1070
1071 /*
1072 * If the last output failed, there's a possibility we need
1073 * to print out the missing entry which would never go out.
1074 */
1075 if (data && data->failed) {
1076 field = &data->ent;
1077 iter->cpu = data->cpu;
1078 ret = print_graph_entry(field, s, iter, flags);
1079 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1080 per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1081 ret = TRACE_TYPE_NO_CONSUME;
1082 }
1083 iter->cpu = cpu;
1084 return ret;
1085 }
1086
1087 switch (entry->type) {
1088 case TRACE_GRAPH_ENT: {
1089 /*
1090 * print_graph_entry() may consume the current event,
1091 * thus @field may become invalid, so we need to save it.
1092 * sizeof(struct ftrace_graph_ent_entry) is very small,
1093 * it can be safely saved at the stack.
1094 */
1095 struct ftrace_graph_ent_entry saved;
1096 trace_assign_type(field, entry);
1097 saved = *field;
1098 return print_graph_entry(&saved, s, iter, flags);
1099 }
1100 case TRACE_GRAPH_RET: {
1101 struct ftrace_graph_ret_entry *field;
1102 trace_assign_type(field, entry);
1103 return print_graph_return(&field->ret, s, entry, iter, flags);
1104 }
1105 case TRACE_STACK:
1106 case TRACE_FN:
1107 /* dont trace stack and functions as comments */
1108 return TRACE_TYPE_UNHANDLED;
1109
1110 default:
1111 return print_graph_comment(s, entry, iter, flags);
1112 }
1113
1114 return TRACE_TYPE_HANDLED;
1115 }
1116
1117 static enum print_line_t
1118 print_graph_function(struct trace_iterator *iter)
1119 {
1120 return print_graph_function_flags(iter, tracer_flags.val);
1121 }
1122
1123 static enum print_line_t
1124 print_graph_function_event(struct trace_iterator *iter, int flags,
1125 struct trace_event *event)
1126 {
1127 return print_graph_function(iter);
1128 }
1129
1130 static void print_lat_header(struct seq_file *s, u32 flags)
1131 {
1132 static const char spaces[] = " " /* 16 spaces */
1133 " " /* 4 spaces */
1134 " "; /* 17 spaces */
1135 int size = 0;
1136
1137 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1138 size += 16;
1139 if (flags & TRACE_GRAPH_PRINT_CPU)
1140 size += 4;
1141 if (flags & TRACE_GRAPH_PRINT_PROC)
1142 size += 17;
1143
1144 seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces);
1145 seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
1146 seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1147 seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
1148 seq_printf(s, "#%.*s||| / _-=> lock-depth \n", size, spaces);
1149 seq_printf(s, "#%.*s|||| / \n", size, spaces);
1150 }
1151
1152 void print_graph_headers_flags(struct seq_file *s, u32 flags)
1153 {
1154 int lat = trace_flags & TRACE_ITER_LATENCY_FMT;
1155
1156 if (lat)
1157 print_lat_header(s, flags);
1158
1159 /* 1st line */
1160 seq_printf(s, "#");
1161 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1162 seq_printf(s, " TIME ");
1163 if (flags & TRACE_GRAPH_PRINT_CPU)
1164 seq_printf(s, " CPU");
1165 if (flags & TRACE_GRAPH_PRINT_PROC)
1166 seq_printf(s, " TASK/PID ");
1167 if (lat)
1168 seq_printf(s, "|||||");
1169 if (flags & TRACE_GRAPH_PRINT_DURATION)
1170 seq_printf(s, " DURATION ");
1171 seq_printf(s, " FUNCTION CALLS\n");
1172
1173 /* 2nd line */
1174 seq_printf(s, "#");
1175 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1176 seq_printf(s, " | ");
1177 if (flags & TRACE_GRAPH_PRINT_CPU)
1178 seq_printf(s, " | ");
1179 if (flags & TRACE_GRAPH_PRINT_PROC)
1180 seq_printf(s, " | | ");
1181 if (lat)
1182 seq_printf(s, "|||||");
1183 if (flags & TRACE_GRAPH_PRINT_DURATION)
1184 seq_printf(s, " | | ");
1185 seq_printf(s, " | | | |\n");
1186 }
1187
1188 void print_graph_headers(struct seq_file *s)
1189 {
1190 print_graph_headers_flags(s, tracer_flags.val);
1191 }
1192
1193 void graph_trace_open(struct trace_iterator *iter)
1194 {
1195 /* pid and depth on the last trace processed */
1196 struct fgraph_data *data;
1197 int cpu;
1198
1199 iter->private = NULL;
1200
1201 data = kzalloc(sizeof(*data), GFP_KERNEL);
1202 if (!data)
1203 goto out_err;
1204
1205 data->cpu_data = alloc_percpu(struct fgraph_cpu_data);
1206 if (!data->cpu_data)
1207 goto out_err_free;
1208
1209 for_each_possible_cpu(cpu) {
1210 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1211 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1212 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1213 *pid = -1;
1214 *depth = 0;
1215 *ignore = 0;
1216 }
1217
1218 iter->private = data;
1219
1220 return;
1221
1222 out_err_free:
1223 kfree(data);
1224 out_err:
1225 pr_warning("function graph tracer: not enough memory\n");
1226 }
1227
1228 void graph_trace_close(struct trace_iterator *iter)
1229 {
1230 struct fgraph_data *data = iter->private;
1231
1232 if (data) {
1233 free_percpu(data->cpu_data);
1234 kfree(data);
1235 }
1236 }
1237
1238 static struct trace_event_functions graph_functions = {
1239 .trace = print_graph_function_event,
1240 };
1241
1242 static struct trace_event graph_trace_entry_event = {
1243 .type = TRACE_GRAPH_ENT,
1244 .funcs = &graph_functions,
1245 };
1246
1247 static struct trace_event graph_trace_ret_event = {
1248 .type = TRACE_GRAPH_RET,
1249 .funcs = &graph_functions
1250 };
1251
1252 static struct tracer graph_trace __read_mostly = {
1253 .name = "function_graph",
1254 .open = graph_trace_open,
1255 .pipe_open = graph_trace_open,
1256 .close = graph_trace_close,
1257 .pipe_close = graph_trace_close,
1258 .wait_pipe = poll_wait_pipe,
1259 .init = graph_trace_init,
1260 .reset = graph_trace_reset,
1261 .print_line = print_graph_function,
1262 .print_header = print_graph_headers,
1263 .flags = &tracer_flags,
1264 #ifdef CONFIG_FTRACE_SELFTEST
1265 .selftest = trace_selftest_startup_function_graph,
1266 #endif
1267 };
1268
1269 static __init int init_graph_trace(void)
1270 {
1271 max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
1272
1273 if (!register_ftrace_event(&graph_trace_entry_event)) {
1274 pr_warning("Warning: could not register graph trace events\n");
1275 return 1;
1276 }
1277
1278 if (!register_ftrace_event(&graph_trace_ret_event)) {
1279 pr_warning("Warning: could not register graph trace events\n");
1280 return 1;
1281 }
1282
1283 return register_tracer(&graph_trace);
1284 }
1285
1286 device_initcall(init_graph_trace);
kernel source for telekom puls (alcatel/mediatek)