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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 */
19static int ftrace_graph_skip_irqs;
20
21struct 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
29struct 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
50static unsigned int max_depth;
51
52static 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
70static 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
77static 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 */
84enum {
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
90static enum print_line_t
91print_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.*/
95int
96ftrace_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(¤t->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.*/
153static void
154ftrace_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(¤t->trace_overrun);
211 trace->depth = index;
212}
213
214/*
215 * Send the trace to the ring-buffer.
216 * @return the original return address.
217 */
218unsigned 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
254int __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
279static 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
287int 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
333int 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
341static 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
361void
362trace_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
369void __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
392void 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
413void 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
422void 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
431static 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
449static void graph_trace_reset(struct trace_array *tr)
450{
451 tracing_stop_cmdline_record();
452 unregister_ftrace_graph();
453}
454
455static int max_bytes_for_cpu;
456
457static enum print_line_t
458print_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
476static enum print_line_t
477print_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
518static enum print_line_t
519print_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 */
528static enum print_line_t
529verif_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
585static struct ftrace_graph_ret_entry *
586get_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
656static 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
667static enum print_line_t
668print_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
728enum print_line_t
729trace_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
771static enum print_line_t
772print_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 */
828static enum print_line_t
829print_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
882static enum print_line_t
883print_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
927static enum print_line_t
928print_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 */
996static int
997check_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 */
1043static int
1044check_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
1087static enum print_line_t
1088print_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
1124static enum print_line_t
1125print_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
1207static enum print_line_t
1208print_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
1277enum print_line_t
1278print_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
1338static enum print_line_t
1339print_graph_function(struct trace_iterator *iter)
1340{
1341 return print_graph_function_flags(iter, tracer_flags.val);
1342}
1343
1344static enum print_line_t
1345print_graph_function_event(struct trace_iterator *iter, int flags,
1346 struct trace_event *event)
1347{
1348 return print_graph_function(iter);
1349}
1350
1351static 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
1372static 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
1408void print_graph_headers(struct seq_file *s)
1409{
1410 print_graph_headers_flags(s, tracer_flags.val);
1411}
1412
1413void 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
1431void 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
1469void 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
1479static int
1480func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
1481{
1482 if (bit == TRACE_GRAPH_PRINT_IRQS)
1483 ftrace_graph_skip_irqs = !set;
1484
1485 return 0;
1486}
1487
1488static struct trace_event_functions graph_functions = {
1489 .trace = print_graph_function_event,
1490};
1491
1492static struct trace_event graph_trace_entry_event = {
1493 .type = TRACE_GRAPH_ENT,
1494 .funcs = &graph_functions,
1495};
1496
1497static struct trace_event graph_trace_ret_event = {
1498 .type = TRACE_GRAPH_RET,
1499 .funcs = &graph_functions
1500};
1501
1502static struct tracer graph_trace __tracer_data = {
1503 .name = "function_graph",
1504 .open = graph_trace_open,
1505 .pipe_open = graph_trace_open,
1506 .close = graph_trace_close,
1507 .pipe_close = graph_trace_close,
1508 .wait_pipe = poll_wait_pipe,
1509 .init = graph_trace_init,
1510 .reset = graph_trace_reset,
1511 .print_line = print_graph_function,
1512 .print_header = print_graph_headers,
1513 .flags = &tracer_flags,
1514 .set_flag = func_graph_set_flag,
1515#ifdef CONFIG_FTRACE_SELFTEST
1516 .selftest = trace_selftest_startup_function_graph,
1517#endif
1518};
1519
1520
1521static ssize_t
1522graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
1523 loff_t *ppos)
1524{
1525 unsigned long val;
1526 int ret;
1527
1528 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1529 if (ret)
1530 return ret;
1531
1532 max_depth = val;
1533
1534 *ppos += cnt;
1535
1536 return cnt;
1537}
1538
1539static ssize_t
1540graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
1541 loff_t *ppos)
1542{
1543 char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/
1544 int n;
1545
1546 n = sprintf(buf, "%d\n", max_depth);
1547
1548 return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
1549}
1550
1551static const struct file_operations graph_depth_fops = {
1552 .open = tracing_open_generic,
1553 .write = graph_depth_write,
1554 .read = graph_depth_read,
1555 .llseek = generic_file_llseek,
1556};
1557
1558static __init int init_graph_debugfs(void)
1559{
1560 struct dentry *d_tracer;
1561
1562 d_tracer = tracing_init_dentry();
1563 if (!d_tracer)
1564 return 0;
1565
1566 trace_create_file("max_graph_depth", 0644, d_tracer,
1567 NULL, &graph_depth_fops);
1568
1569 return 0;
1570}
1571fs_initcall(init_graph_debugfs);
1572
1573static __init int init_graph_trace(void)
1574{
1575 max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
1576
1577 if (!register_ftrace_event(&graph_trace_entry_event)) {
1578 pr_warning("Warning: could not register graph trace events\n");
1579 return 1;
1580 }
1581
1582 if (!register_ftrace_event(&graph_trace_ret_event)) {
1583 pr_warning("Warning: could not register graph trace events\n");
1584 return 1;
1585 }
1586
1587 return register_tracer(&graph_trace);
1588}
1589
1590core_initcall(init_graph_trace);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 *
4 * Function graph tracer.
5 * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
6 * Mostly borrowed from function tracer which
7 * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
8 *
9 */
10#include <linux/uaccess.h>
11#include <linux/ftrace.h>
12#include <linux/interrupt.h>
13#include <linux/slab.h>
14#include <linux/fs.h>
15
16#include "trace.h"
17#include "trace_output.h"
18
19/* When set, irq functions will be ignored */
20static int ftrace_graph_skip_irqs;
21
22struct fgraph_cpu_data {
23 pid_t last_pid;
24 int depth;
25 int depth_irq;
26 int ignore;
27 unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH];
28};
29
30struct fgraph_data {
31 struct fgraph_cpu_data __percpu *cpu_data;
32
33 /* Place to preserve last processed entry. */
34 union {
35 struct ftrace_graph_ent_entry ent;
36 struct fgraph_retaddr_ent_entry rent;
37 } ent;
38 struct ftrace_graph_ret_entry ret;
39 int failed;
40 int cpu;
41};
42
43#define TRACE_GRAPH_INDENT 2
44
45unsigned int fgraph_max_depth;
46
47static struct tracer_opt trace_opts[] = {
48 /* Display overruns? (for self-debug purpose) */
49 { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
50 /* Display CPU ? */
51 { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
52 /* Display Overhead ? */
53 { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
54 /* Display proc name/pid */
55 { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
56 /* Display duration of execution */
57 { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
58 /* Display absolute time of an entry */
59 { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
60 /* Display interrupts */
61 { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
62 /* Display function name after trailing } */
63 { TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) },
64#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
65 /* Display function return value ? */
66 { TRACER_OPT(funcgraph-retval, TRACE_GRAPH_PRINT_RETVAL) },
67 /* Display function return value in hexadecimal format ? */
68 { TRACER_OPT(funcgraph-retval-hex, TRACE_GRAPH_PRINT_RETVAL_HEX) },
69#endif
70#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
71 /* Display function return address ? */
72 { TRACER_OPT(funcgraph-retaddr, TRACE_GRAPH_PRINT_RETADDR) },
73#endif
74 /* Include sleep time (scheduled out) between entry and return */
75 { TRACER_OPT(sleep-time, TRACE_GRAPH_SLEEP_TIME) },
76
77#ifdef CONFIG_FUNCTION_PROFILER
78 /* Include time within nested functions */
79 { TRACER_OPT(graph-time, TRACE_GRAPH_GRAPH_TIME) },
80#endif
81
82 { } /* Empty entry */
83};
84
85static struct tracer_flags tracer_flags = {
86 /* Don't display overruns, proc, or tail by default */
87 .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
88 TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS |
89 TRACE_GRAPH_SLEEP_TIME | TRACE_GRAPH_GRAPH_TIME,
90 .opts = trace_opts
91};
92
93static bool tracer_flags_is_set(u32 flags)
94{
95 return (tracer_flags.val & flags) == flags;
96}
97
98/*
99 * DURATION column is being also used to display IRQ signs,
100 * following values are used by print_graph_irq and others
101 * to fill in space into DURATION column.
102 */
103enum {
104 FLAGS_FILL_FULL = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT,
105 FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT,
106 FLAGS_FILL_END = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT,
107};
108
109static void
110print_graph_duration(struct trace_array *tr, unsigned long long duration,
111 struct trace_seq *s, u32 flags);
112
113int __trace_graph_entry(struct trace_array *tr,
114 struct ftrace_graph_ent *trace,
115 unsigned int trace_ctx)
116{
117 struct ring_buffer_event *event;
118 struct trace_buffer *buffer = tr->array_buffer.buffer;
119 struct ftrace_graph_ent_entry *entry;
120
121 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
122 sizeof(*entry), trace_ctx);
123 if (!event)
124 return 0;
125 entry = ring_buffer_event_data(event);
126 entry->graph_ent = *trace;
127 trace_buffer_unlock_commit_nostack(buffer, event);
128
129 return 1;
130}
131
132#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
133int __trace_graph_retaddr_entry(struct trace_array *tr,
134 struct ftrace_graph_ent *trace,
135 unsigned int trace_ctx,
136 unsigned long retaddr)
137{
138 struct ring_buffer_event *event;
139 struct trace_buffer *buffer = tr->array_buffer.buffer;
140 struct fgraph_retaddr_ent_entry *entry;
141
142 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RETADDR_ENT,
143 sizeof(*entry), trace_ctx);
144 if (!event)
145 return 0;
146 entry = ring_buffer_event_data(event);
147 entry->graph_ent.func = trace->func;
148 entry->graph_ent.depth = trace->depth;
149 entry->graph_ent.retaddr = retaddr;
150 trace_buffer_unlock_commit_nostack(buffer, event);
151
152 return 1;
153}
154#else
155int __trace_graph_retaddr_entry(struct trace_array *tr,
156 struct ftrace_graph_ent *trace,
157 unsigned int trace_ctx,
158 unsigned long retaddr)
159{
160 return 1;
161}
162#endif
163
164static inline int ftrace_graph_ignore_irqs(void)
165{
166 if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT))
167 return 0;
168
169 return in_hardirq();
170}
171
172struct fgraph_times {
173 unsigned long long calltime;
174 unsigned long long sleeptime; /* may be optional! */
175};
176
177int trace_graph_entry(struct ftrace_graph_ent *trace,
178 struct fgraph_ops *gops)
179{
180 unsigned long *task_var = fgraph_get_task_var(gops);
181 struct trace_array *tr = gops->private;
182 struct trace_array_cpu *data;
183 struct fgraph_times *ftimes;
184 unsigned long flags;
185 unsigned int trace_ctx;
186 long disabled;
187 int ret;
188 int cpu;
189
190 if (*task_var & TRACE_GRAPH_NOTRACE)
191 return 0;
192
193 /*
194 * Do not trace a function if it's filtered by set_graph_notrace.
195 * Make the index of ret stack negative to indicate that it should
196 * ignore further functions. But it needs its own ret stack entry
197 * to recover the original index in order to continue tracing after
198 * returning from the function.
199 */
200 if (ftrace_graph_notrace_addr(trace->func)) {
201 *task_var |= TRACE_GRAPH_NOTRACE;
202 /*
203 * Need to return 1 to have the return called
204 * that will clear the NOTRACE bit.
205 */
206 return 1;
207 }
208
209 if (!ftrace_trace_task(tr))
210 return 0;
211
212 if (ftrace_graph_ignore_func(gops, trace))
213 return 0;
214
215 if (ftrace_graph_ignore_irqs())
216 return 0;
217
218 if (fgraph_sleep_time) {
219 /* Only need to record the calltime */
220 ftimes = fgraph_reserve_data(gops->idx, sizeof(ftimes->calltime));
221 } else {
222 ftimes = fgraph_reserve_data(gops->idx, sizeof(*ftimes));
223 if (ftimes)
224 ftimes->sleeptime = current->ftrace_sleeptime;
225 }
226 if (!ftimes)
227 return 0;
228
229 ftimes->calltime = trace_clock_local();
230
231 /*
232 * Stop here if tracing_threshold is set. We only write function return
233 * events to the ring buffer.
234 */
235 if (tracing_thresh)
236 return 1;
237
238 local_irq_save(flags);
239 cpu = raw_smp_processor_id();
240 data = per_cpu_ptr(tr->array_buffer.data, cpu);
241 disabled = atomic_inc_return(&data->disabled);
242 if (likely(disabled == 1)) {
243 trace_ctx = tracing_gen_ctx_flags(flags);
244 if (unlikely(IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) &&
245 tracer_flags_is_set(TRACE_GRAPH_PRINT_RETADDR))) {
246 unsigned long retaddr = ftrace_graph_top_ret_addr(current);
247
248 ret = __trace_graph_retaddr_entry(tr, trace, trace_ctx, retaddr);
249 } else
250 ret = __trace_graph_entry(tr, trace, trace_ctx);
251 } else {
252 ret = 0;
253 }
254
255 atomic_dec(&data->disabled);
256 local_irq_restore(flags);
257
258 return ret;
259}
260
261static void
262__trace_graph_function(struct trace_array *tr,
263 unsigned long ip, unsigned int trace_ctx)
264{
265 u64 time = trace_clock_local();
266 struct ftrace_graph_ent ent = {
267 .func = ip,
268 .depth = 0,
269 };
270 struct ftrace_graph_ret ret = {
271 .func = ip,
272 .depth = 0,
273 .calltime = time,
274 .rettime = time,
275 };
276
277 __trace_graph_entry(tr, &ent, trace_ctx);
278 __trace_graph_return(tr, &ret, trace_ctx);
279}
280
281void
282trace_graph_function(struct trace_array *tr,
283 unsigned long ip, unsigned long parent_ip,
284 unsigned int trace_ctx)
285{
286 __trace_graph_function(tr, ip, trace_ctx);
287}
288
289void __trace_graph_return(struct trace_array *tr,
290 struct ftrace_graph_ret *trace,
291 unsigned int trace_ctx)
292{
293 struct ring_buffer_event *event;
294 struct trace_buffer *buffer = tr->array_buffer.buffer;
295 struct ftrace_graph_ret_entry *entry;
296
297 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
298 sizeof(*entry), trace_ctx);
299 if (!event)
300 return;
301 entry = ring_buffer_event_data(event);
302 entry->ret = *trace;
303 trace_buffer_unlock_commit_nostack(buffer, event);
304}
305
306static void handle_nosleeptime(struct ftrace_graph_ret *trace,
307 struct fgraph_times *ftimes,
308 int size)
309{
310 if (fgraph_sleep_time || size < sizeof(*ftimes))
311 return;
312
313 ftimes->calltime += current->ftrace_sleeptime - ftimes->sleeptime;
314}
315
316void trace_graph_return(struct ftrace_graph_ret *trace,
317 struct fgraph_ops *gops)
318{
319 unsigned long *task_var = fgraph_get_task_var(gops);
320 struct trace_array *tr = gops->private;
321 struct trace_array_cpu *data;
322 struct fgraph_times *ftimes;
323 unsigned long flags;
324 unsigned int trace_ctx;
325 long disabled;
326 int size;
327 int cpu;
328
329 ftrace_graph_addr_finish(gops, trace);
330
331 if (*task_var & TRACE_GRAPH_NOTRACE) {
332 *task_var &= ~TRACE_GRAPH_NOTRACE;
333 return;
334 }
335
336 ftimes = fgraph_retrieve_data(gops->idx, &size);
337 if (!ftimes)
338 return;
339
340 handle_nosleeptime(trace, ftimes, size);
341
342 trace->calltime = ftimes->calltime;
343
344 local_irq_save(flags);
345 cpu = raw_smp_processor_id();
346 data = per_cpu_ptr(tr->array_buffer.data, cpu);
347 disabled = atomic_inc_return(&data->disabled);
348 if (likely(disabled == 1)) {
349 trace_ctx = tracing_gen_ctx_flags(flags);
350 __trace_graph_return(tr, trace, trace_ctx);
351 }
352 atomic_dec(&data->disabled);
353 local_irq_restore(flags);
354}
355
356static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
357 struct fgraph_ops *gops)
358{
359 struct fgraph_times *ftimes;
360 int size;
361
362 ftrace_graph_addr_finish(gops, trace);
363
364 if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) {
365 trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT);
366 return;
367 }
368
369 ftimes = fgraph_retrieve_data(gops->idx, &size);
370 if (!ftimes)
371 return;
372
373 handle_nosleeptime(trace, ftimes, size);
374
375 trace->calltime = ftimes->calltime;
376
377 if (tracing_thresh &&
378 (trace->rettime - ftimes->calltime < tracing_thresh))
379 return;
380 else
381 trace_graph_return(trace, gops);
382}
383
384static struct fgraph_ops funcgraph_ops = {
385 .entryfunc = &trace_graph_entry,
386 .retfunc = &trace_graph_return,
387};
388
389int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops)
390{
391 struct fgraph_ops *gops;
392
393 gops = kzalloc(sizeof(*gops), GFP_KERNEL);
394 if (!gops)
395 return -ENOMEM;
396
397 gops->entryfunc = &trace_graph_entry;
398 gops->retfunc = &trace_graph_return;
399
400 tr->gops = gops;
401 gops->private = tr;
402
403 fgraph_init_ops(&gops->ops, ops);
404
405 return 0;
406}
407
408void free_fgraph_ops(struct trace_array *tr)
409{
410 kfree(tr->gops);
411}
412
413__init void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops)
414{
415 tr->gops = &funcgraph_ops;
416 funcgraph_ops.private = tr;
417 fgraph_init_ops(&tr->gops->ops, ops);
418}
419
420static int graph_trace_init(struct trace_array *tr)
421{
422 int ret;
423
424 tr->gops->entryfunc = trace_graph_entry;
425
426 if (tracing_thresh)
427 tr->gops->retfunc = trace_graph_thresh_return;
428 else
429 tr->gops->retfunc = trace_graph_return;
430
431 /* Make gops functions are visible before we start tracing */
432 smp_mb();
433
434 ret = register_ftrace_graph(tr->gops);
435 if (ret)
436 return ret;
437 tracing_start_cmdline_record();
438
439 return 0;
440}
441
442static void graph_trace_reset(struct trace_array *tr)
443{
444 tracing_stop_cmdline_record();
445 unregister_ftrace_graph(tr->gops);
446}
447
448static int graph_trace_update_thresh(struct trace_array *tr)
449{
450 graph_trace_reset(tr);
451 return graph_trace_init(tr);
452}
453
454static int max_bytes_for_cpu;
455
456static void print_graph_cpu(struct trace_seq *s, int cpu)
457{
458 /*
459 * Start with a space character - to make it stand out
460 * to the right a bit when trace output is pasted into
461 * email:
462 */
463 trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
464}
465
466#define TRACE_GRAPH_PROCINFO_LENGTH 14
467
468static void print_graph_proc(struct trace_seq *s, pid_t pid)
469{
470 char comm[TASK_COMM_LEN];
471 /* sign + log10(MAX_INT) + '\0' */
472 char pid_str[11];
473 int spaces = 0;
474 int len;
475 int i;
476
477 trace_find_cmdline(pid, comm);
478 comm[7] = '\0';
479 sprintf(pid_str, "%d", pid);
480
481 /* 1 stands for the "-" character */
482 len = strlen(comm) + strlen(pid_str) + 1;
483
484 if (len < TRACE_GRAPH_PROCINFO_LENGTH)
485 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
486
487 /* First spaces to align center */
488 for (i = 0; i < spaces / 2; i++)
489 trace_seq_putc(s, ' ');
490
491 trace_seq_printf(s, "%s-%s", comm, pid_str);
492
493 /* Last spaces to align center */
494 for (i = 0; i < spaces - (spaces / 2); i++)
495 trace_seq_putc(s, ' ');
496}
497
498
499static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
500{
501 trace_seq_putc(s, ' ');
502 trace_print_lat_fmt(s, entry);
503 trace_seq_puts(s, " | ");
504}
505
506/* If the pid changed since the last trace, output this event */
507static void
508verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data)
509{
510 pid_t prev_pid;
511 pid_t *last_pid;
512
513 if (!data)
514 return;
515
516 last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
517
518 if (*last_pid == pid)
519 return;
520
521 prev_pid = *last_pid;
522 *last_pid = pid;
523
524 if (prev_pid == -1)
525 return;
526/*
527 * Context-switch trace line:
528
529 ------------------------------------------
530 | 1) migration/0--1 => sshd-1755
531 ------------------------------------------
532
533 */
534 trace_seq_puts(s, " ------------------------------------------\n");
535 print_graph_cpu(s, cpu);
536 print_graph_proc(s, prev_pid);
537 trace_seq_puts(s, " => ");
538 print_graph_proc(s, pid);
539 trace_seq_puts(s, "\n ------------------------------------------\n\n");
540}
541
542static struct ftrace_graph_ret_entry *
543get_return_for_leaf(struct trace_iterator *iter,
544 struct ftrace_graph_ent_entry *curr)
545{
546 struct fgraph_data *data = iter->private;
547 struct ring_buffer_iter *ring_iter = NULL;
548 struct ring_buffer_event *event;
549 struct ftrace_graph_ret_entry *next;
550
551 /*
552 * If the previous output failed to write to the seq buffer,
553 * then we just reuse the data from before.
554 */
555 if (data && data->failed) {
556 curr = &data->ent.ent;
557 next = &data->ret;
558 } else {
559
560 ring_iter = trace_buffer_iter(iter, iter->cpu);
561
562 /* First peek to compare current entry and the next one */
563 if (ring_iter)
564 event = ring_buffer_iter_peek(ring_iter, NULL);
565 else {
566 /*
567 * We need to consume the current entry to see
568 * the next one.
569 */
570 ring_buffer_consume(iter->array_buffer->buffer, iter->cpu,
571 NULL, NULL);
572 event = ring_buffer_peek(iter->array_buffer->buffer, iter->cpu,
573 NULL, NULL);
574 }
575
576 if (!event)
577 return NULL;
578
579 next = ring_buffer_event_data(event);
580
581 if (data) {
582 /*
583 * Save current and next entries for later reference
584 * if the output fails.
585 */
586 if (unlikely(curr->ent.type == TRACE_GRAPH_RETADDR_ENT))
587 data->ent.rent = *(struct fgraph_retaddr_ent_entry *)curr;
588 else
589 data->ent.ent = *curr;
590 /*
591 * If the next event is not a return type, then
592 * we only care about what type it is. Otherwise we can
593 * safely copy the entire event.
594 */
595 if (next->ent.type == TRACE_GRAPH_RET)
596 data->ret = *next;
597 else
598 data->ret.ent.type = next->ent.type;
599 }
600 }
601
602 if (next->ent.type != TRACE_GRAPH_RET)
603 return NULL;
604
605 if (curr->ent.pid != next->ent.pid ||
606 curr->graph_ent.func != next->ret.func)
607 return NULL;
608
609 /* this is a leaf, now advance the iterator */
610 if (ring_iter)
611 ring_buffer_iter_advance(ring_iter);
612
613 return next;
614}
615
616static void print_graph_abs_time(u64 t, struct trace_seq *s)
617{
618 unsigned long usecs_rem;
619
620 usecs_rem = do_div(t, NSEC_PER_SEC);
621 usecs_rem /= 1000;
622
623 trace_seq_printf(s, "%5lu.%06lu | ",
624 (unsigned long)t, usecs_rem);
625}
626
627static void
628print_graph_rel_time(struct trace_iterator *iter, struct trace_seq *s)
629{
630 unsigned long long usecs;
631
632 usecs = iter->ts - iter->array_buffer->time_start;
633 do_div(usecs, NSEC_PER_USEC);
634
635 trace_seq_printf(s, "%9llu us | ", usecs);
636}
637
638static void
639print_graph_irq(struct trace_iterator *iter, unsigned long addr,
640 enum trace_type type, int cpu, pid_t pid, u32 flags)
641{
642 struct trace_array *tr = iter->tr;
643 struct trace_seq *s = &iter->seq;
644 struct trace_entry *ent = iter->ent;
645
646 addr += iter->tr->text_delta;
647
648 if (addr < (unsigned long)__irqentry_text_start ||
649 addr >= (unsigned long)__irqentry_text_end)
650 return;
651
652 if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
653 /* Absolute time */
654 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
655 print_graph_abs_time(iter->ts, s);
656
657 /* Relative time */
658 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
659 print_graph_rel_time(iter, s);
660
661 /* Cpu */
662 if (flags & TRACE_GRAPH_PRINT_CPU)
663 print_graph_cpu(s, cpu);
664
665 /* Proc */
666 if (flags & TRACE_GRAPH_PRINT_PROC) {
667 print_graph_proc(s, pid);
668 trace_seq_puts(s, " | ");
669 }
670
671 /* Latency format */
672 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
673 print_graph_lat_fmt(s, ent);
674 }
675
676 /* No overhead */
677 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_START);
678
679 if (type == TRACE_GRAPH_ENT)
680 trace_seq_puts(s, "==========>");
681 else
682 trace_seq_puts(s, "<==========");
683
684 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_END);
685 trace_seq_putc(s, '\n');
686}
687
688void
689trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
690{
691 unsigned long nsecs_rem = do_div(duration, 1000);
692 /* log10(ULONG_MAX) + '\0' */
693 char usecs_str[21];
694 char nsecs_str[5];
695 int len;
696 int i;
697
698 sprintf(usecs_str, "%lu", (unsigned long) duration);
699
700 /* Print msecs */
701 trace_seq_printf(s, "%s", usecs_str);
702
703 len = strlen(usecs_str);
704
705 /* Print nsecs (we don't want to exceed 7 numbers) */
706 if (len < 7) {
707 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
708
709 snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
710 trace_seq_printf(s, ".%s", nsecs_str);
711 len += strlen(nsecs_str) + 1;
712 }
713
714 trace_seq_puts(s, " us ");
715
716 /* Print remaining spaces to fit the row's width */
717 for (i = len; i < 8; i++)
718 trace_seq_putc(s, ' ');
719}
720
721static void
722print_graph_duration(struct trace_array *tr, unsigned long long duration,
723 struct trace_seq *s, u32 flags)
724{
725 if (!(flags & TRACE_GRAPH_PRINT_DURATION) ||
726 !(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
727 return;
728
729 /* No real adata, just filling the column with spaces */
730 switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) {
731 case FLAGS_FILL_FULL:
732 trace_seq_puts(s, " | ");
733 return;
734 case FLAGS_FILL_START:
735 trace_seq_puts(s, " ");
736 return;
737 case FLAGS_FILL_END:
738 trace_seq_puts(s, " |");
739 return;
740 }
741
742 /* Signal a overhead of time execution to the output */
743 if (flags & TRACE_GRAPH_PRINT_OVERHEAD)
744 trace_seq_printf(s, "%c ", trace_find_mark(duration));
745 else
746 trace_seq_puts(s, " ");
747
748 trace_print_graph_duration(duration, s);
749 trace_seq_puts(s, "| ");
750}
751
752#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
753#define __TRACE_GRAPH_PRINT_RETVAL TRACE_GRAPH_PRINT_RETVAL
754#else
755#define __TRACE_GRAPH_PRINT_RETVAL 0
756#endif
757
758#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
759#define __TRACE_GRAPH_PRINT_RETADDR TRACE_GRAPH_PRINT_RETADDR
760static void print_graph_retaddr(struct trace_seq *s, struct fgraph_retaddr_ent_entry *entry,
761 u32 trace_flags, bool comment)
762{
763 if (comment)
764 trace_seq_puts(s, " /*");
765
766 trace_seq_puts(s, " <-");
767 seq_print_ip_sym(s, entry->graph_ent.retaddr, trace_flags | TRACE_ITER_SYM_OFFSET);
768
769 if (comment)
770 trace_seq_puts(s, " */");
771}
772#else
773#define __TRACE_GRAPH_PRINT_RETADDR 0
774#define print_graph_retaddr(_seq, _entry, _tflags, _comment) do { } while (0)
775#endif
776
777#if defined(CONFIG_FUNCTION_GRAPH_RETVAL) || defined(CONFIG_FUNCTION_GRAPH_RETADDR)
778
779static void print_graph_retval(struct trace_seq *s, struct ftrace_graph_ent_entry *entry,
780 struct ftrace_graph_ret *graph_ret, void *func,
781 u32 opt_flags, u32 trace_flags)
782{
783 unsigned long err_code = 0;
784 unsigned long retval = 0;
785 bool print_retaddr = false;
786 bool print_retval = false;
787 bool hex_format = !!(opt_flags & TRACE_GRAPH_PRINT_RETVAL_HEX);
788
789#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
790 retval = graph_ret->retval;
791 print_retval = !!(opt_flags & TRACE_GRAPH_PRINT_RETVAL);
792#endif
793
794#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
795 print_retaddr = !!(opt_flags & TRACE_GRAPH_PRINT_RETADDR);
796#endif
797
798 if (print_retval && retval && !hex_format) {
799 /* Check if the return value matches the negative format */
800 if (IS_ENABLED(CONFIG_64BIT) && (retval & BIT(31)) &&
801 (((u64)retval) >> 32) == 0) {
802 err_code = sign_extend64(retval, 31);
803 } else {
804 err_code = retval;
805 }
806
807 if (!IS_ERR_VALUE(err_code))
808 err_code = 0;
809 }
810
811 if (entry) {
812 if (entry->ent.type != TRACE_GRAPH_RETADDR_ENT)
813 print_retaddr = false;
814
815 trace_seq_printf(s, "%ps();", func);
816 if (print_retval || print_retaddr)
817 trace_seq_puts(s, " /*");
818 else
819 trace_seq_putc(s, '\n');
820 } else {
821 print_retaddr = false;
822 trace_seq_printf(s, "} /* %ps", func);
823 }
824
825 if (print_retaddr)
826 print_graph_retaddr(s, (struct fgraph_retaddr_ent_entry *)entry,
827 trace_flags, false);
828
829 if (print_retval) {
830 if (hex_format || (err_code == 0))
831 trace_seq_printf(s, " ret=0x%lx", retval);
832 else
833 trace_seq_printf(s, " ret=%ld", err_code);
834 }
835
836 if (!entry || print_retval || print_retaddr)
837 trace_seq_puts(s, " */\n");
838}
839
840#else
841
842#define print_graph_retval(_seq, _ent, _ret, _func, _opt_flags, _trace_flags) do {} while (0)
843
844#endif
845
846/* Case of a leaf function on its call entry */
847static enum print_line_t
848print_graph_entry_leaf(struct trace_iterator *iter,
849 struct ftrace_graph_ent_entry *entry,
850 struct ftrace_graph_ret_entry *ret_entry,
851 struct trace_seq *s, u32 flags)
852{
853 struct fgraph_data *data = iter->private;
854 struct trace_array *tr = iter->tr;
855 struct ftrace_graph_ret *graph_ret;
856 struct ftrace_graph_ent *call;
857 unsigned long long duration;
858 unsigned long func;
859 int cpu = iter->cpu;
860 int i;
861
862 graph_ret = &ret_entry->ret;
863 call = &entry->graph_ent;
864 duration = graph_ret->rettime - graph_ret->calltime;
865
866 func = call->func + iter->tr->text_delta;
867
868 if (data) {
869 struct fgraph_cpu_data *cpu_data;
870
871 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
872
873 /*
874 * Comments display at + 1 to depth. Since
875 * this is a leaf function, keep the comments
876 * equal to this depth.
877 */
878 cpu_data->depth = call->depth - 1;
879
880 /* No need to keep this function around for this depth */
881 if (call->depth < FTRACE_RETFUNC_DEPTH &&
882 !WARN_ON_ONCE(call->depth < 0))
883 cpu_data->enter_funcs[call->depth] = 0;
884 }
885
886 /* Overhead and duration */
887 print_graph_duration(tr, duration, s, flags);
888
889 /* Function */
890 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
891 trace_seq_putc(s, ' ');
892
893 /*
894 * Write out the function return value or return address
895 */
896 if (flags & (__TRACE_GRAPH_PRINT_RETVAL | __TRACE_GRAPH_PRINT_RETADDR)) {
897 print_graph_retval(s, entry, graph_ret,
898 (void *)graph_ret->func + iter->tr->text_delta,
899 flags, tr->trace_flags);
900 } else {
901 trace_seq_printf(s, "%ps();\n", (void *)func);
902 }
903
904 print_graph_irq(iter, graph_ret->func, TRACE_GRAPH_RET,
905 cpu, iter->ent->pid, flags);
906
907 return trace_handle_return(s);
908}
909
910static enum print_line_t
911print_graph_entry_nested(struct trace_iterator *iter,
912 struct ftrace_graph_ent_entry *entry,
913 struct trace_seq *s, int cpu, u32 flags)
914{
915 struct ftrace_graph_ent *call = &entry->graph_ent;
916 struct fgraph_data *data = iter->private;
917 struct trace_array *tr = iter->tr;
918 unsigned long func;
919 int i;
920
921 if (data) {
922 struct fgraph_cpu_data *cpu_data;
923 int cpu = iter->cpu;
924
925 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
926 cpu_data->depth = call->depth;
927
928 /* Save this function pointer to see if the exit matches */
929 if (call->depth < FTRACE_RETFUNC_DEPTH &&
930 !WARN_ON_ONCE(call->depth < 0))
931 cpu_data->enter_funcs[call->depth] = call->func;
932 }
933
934 /* No time */
935 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
936
937 /* Function */
938 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++)
939 trace_seq_putc(s, ' ');
940
941 func = call->func + iter->tr->text_delta;
942
943 trace_seq_printf(s, "%ps() {", (void *)func);
944 if (flags & __TRACE_GRAPH_PRINT_RETADDR &&
945 entry->ent.type == TRACE_GRAPH_RETADDR_ENT)
946 print_graph_retaddr(s, (struct fgraph_retaddr_ent_entry *)entry,
947 tr->trace_flags, true);
948 trace_seq_putc(s, '\n');
949
950 if (trace_seq_has_overflowed(s))
951 return TRACE_TYPE_PARTIAL_LINE;
952
953 /*
954 * we already consumed the current entry to check the next one
955 * and see if this is a leaf.
956 */
957 return TRACE_TYPE_NO_CONSUME;
958}
959
960static void
961print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
962 int type, unsigned long addr, u32 flags)
963{
964 struct fgraph_data *data = iter->private;
965 struct trace_entry *ent = iter->ent;
966 struct trace_array *tr = iter->tr;
967 int cpu = iter->cpu;
968
969 /* Pid */
970 verif_pid(s, ent->pid, cpu, data);
971
972 if (type)
973 /* Interrupt */
974 print_graph_irq(iter, addr, type, cpu, ent->pid, flags);
975
976 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
977 return;
978
979 /* Absolute time */
980 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
981 print_graph_abs_time(iter->ts, s);
982
983 /* Relative time */
984 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
985 print_graph_rel_time(iter, s);
986
987 /* Cpu */
988 if (flags & TRACE_GRAPH_PRINT_CPU)
989 print_graph_cpu(s, cpu);
990
991 /* Proc */
992 if (flags & TRACE_GRAPH_PRINT_PROC) {
993 print_graph_proc(s, ent->pid);
994 trace_seq_puts(s, " | ");
995 }
996
997 /* Latency format */
998 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
999 print_graph_lat_fmt(s, ent);
1000
1001 return;
1002}
1003
1004/*
1005 * Entry check for irq code
1006 *
1007 * returns 1 if
1008 * - we are inside irq code
1009 * - we just entered irq code
1010 *
1011 * returns 0 if
1012 * - funcgraph-interrupts option is set
1013 * - we are not inside irq code
1014 */
1015static int
1016check_irq_entry(struct trace_iterator *iter, u32 flags,
1017 unsigned long addr, int depth)
1018{
1019 int cpu = iter->cpu;
1020 int *depth_irq;
1021 struct fgraph_data *data = iter->private;
1022
1023 addr += iter->tr->text_delta;
1024
1025 /*
1026 * If we are either displaying irqs, or we got called as
1027 * a graph event and private data does not exist,
1028 * then we bypass the irq check.
1029 */
1030 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
1031 (!data))
1032 return 0;
1033
1034 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1035
1036 /*
1037 * We are inside the irq code
1038 */
1039 if (*depth_irq >= 0)
1040 return 1;
1041
1042 if ((addr < (unsigned long)__irqentry_text_start) ||
1043 (addr >= (unsigned long)__irqentry_text_end))
1044 return 0;
1045
1046 /*
1047 * We are entering irq code.
1048 */
1049 *depth_irq = depth;
1050 return 1;
1051}
1052
1053/*
1054 * Return check for irq code
1055 *
1056 * returns 1 if
1057 * - we are inside irq code
1058 * - we just left irq code
1059 *
1060 * returns 0 if
1061 * - funcgraph-interrupts option is set
1062 * - we are not inside irq code
1063 */
1064static int
1065check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
1066{
1067 int cpu = iter->cpu;
1068 int *depth_irq;
1069 struct fgraph_data *data = iter->private;
1070
1071 /*
1072 * If we are either displaying irqs, or we got called as
1073 * a graph event and private data does not exist,
1074 * then we bypass the irq check.
1075 */
1076 if ((flags & TRACE_GRAPH_PRINT_IRQS) ||
1077 (!data))
1078 return 0;
1079
1080 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1081
1082 /*
1083 * We are not inside the irq code.
1084 */
1085 if (*depth_irq == -1)
1086 return 0;
1087
1088 /*
1089 * We are inside the irq code, and this is returning entry.
1090 * Let's not trace it and clear the entry depth, since
1091 * we are out of irq code.
1092 *
1093 * This condition ensures that we 'leave the irq code' once
1094 * we are out of the entry depth. Thus protecting us from
1095 * the RETURN entry loss.
1096 */
1097 if (*depth_irq >= depth) {
1098 *depth_irq = -1;
1099 return 1;
1100 }
1101
1102 /*
1103 * We are inside the irq code, and this is not the entry.
1104 */
1105 return 1;
1106}
1107
1108static enum print_line_t
1109print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
1110 struct trace_iterator *iter, u32 flags)
1111{
1112 struct fgraph_data *data = iter->private;
1113 struct ftrace_graph_ent *call = &field->graph_ent;
1114 struct ftrace_graph_ret_entry *leaf_ret;
1115 static enum print_line_t ret;
1116 int cpu = iter->cpu;
1117
1118 if (check_irq_entry(iter, flags, call->func, call->depth))
1119 return TRACE_TYPE_HANDLED;
1120
1121 print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags);
1122
1123 leaf_ret = get_return_for_leaf(iter, field);
1124 if (leaf_ret)
1125 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags);
1126 else
1127 ret = print_graph_entry_nested(iter, field, s, cpu, flags);
1128
1129 if (data) {
1130 /*
1131 * If we failed to write our output, then we need to make
1132 * note of it. Because we already consumed our entry.
1133 */
1134 if (s->full) {
1135 data->failed = 1;
1136 data->cpu = cpu;
1137 } else
1138 data->failed = 0;
1139 }
1140
1141 return ret;
1142}
1143
1144static enum print_line_t
1145print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
1146 struct trace_entry *ent, struct trace_iterator *iter,
1147 u32 flags)
1148{
1149 unsigned long long duration = trace->rettime - trace->calltime;
1150 struct fgraph_data *data = iter->private;
1151 struct trace_array *tr = iter->tr;
1152 unsigned long func;
1153 pid_t pid = ent->pid;
1154 int cpu = iter->cpu;
1155 int func_match = 1;
1156 int i;
1157
1158 func = trace->func + iter->tr->text_delta;
1159
1160 if (check_irq_return(iter, flags, trace->depth))
1161 return TRACE_TYPE_HANDLED;
1162
1163 if (data) {
1164 struct fgraph_cpu_data *cpu_data;
1165 int cpu = iter->cpu;
1166
1167 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1168
1169 /*
1170 * Comments display at + 1 to depth. This is the
1171 * return from a function, we now want the comments
1172 * to display at the same level of the bracket.
1173 */
1174 cpu_data->depth = trace->depth - 1;
1175
1176 if (trace->depth < FTRACE_RETFUNC_DEPTH &&
1177 !WARN_ON_ONCE(trace->depth < 0)) {
1178 if (cpu_data->enter_funcs[trace->depth] != trace->func)
1179 func_match = 0;
1180 cpu_data->enter_funcs[trace->depth] = 0;
1181 }
1182 }
1183
1184 print_graph_prologue(iter, s, 0, 0, flags);
1185
1186 /* Overhead and duration */
1187 print_graph_duration(tr, duration, s, flags);
1188
1189 /* Closing brace */
1190 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++)
1191 trace_seq_putc(s, ' ');
1192
1193 /*
1194 * Always write out the function name and its return value if the
1195 * funcgraph-retval option is enabled.
1196 */
1197 if (flags & __TRACE_GRAPH_PRINT_RETVAL) {
1198 print_graph_retval(s, NULL, trace, (void *)func, flags, tr->trace_flags);
1199 } else {
1200 /*
1201 * If the return function does not have a matching entry,
1202 * then the entry was lost. Instead of just printing
1203 * the '}' and letting the user guess what function this
1204 * belongs to, write out the function name. Always do
1205 * that if the funcgraph-tail option is enabled.
1206 */
1207 if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL))
1208 trace_seq_puts(s, "}\n");
1209 else
1210 trace_seq_printf(s, "} /* %ps */\n", (void *)func);
1211 }
1212
1213 /* Overrun */
1214 if (flags & TRACE_GRAPH_PRINT_OVERRUN)
1215 trace_seq_printf(s, " (Overruns: %u)\n",
1216 trace->overrun);
1217
1218 print_graph_irq(iter, trace->func, TRACE_GRAPH_RET,
1219 cpu, pid, flags);
1220
1221 return trace_handle_return(s);
1222}
1223
1224static enum print_line_t
1225print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
1226 struct trace_iterator *iter, u32 flags)
1227{
1228 struct trace_array *tr = iter->tr;
1229 unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
1230 struct fgraph_data *data = iter->private;
1231 struct trace_event *event;
1232 int depth = 0;
1233 int ret;
1234 int i;
1235
1236 if (data)
1237 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth;
1238
1239 print_graph_prologue(iter, s, 0, 0, flags);
1240
1241 /* No time */
1242 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
1243
1244 /* Indentation */
1245 if (depth > 0)
1246 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++)
1247 trace_seq_putc(s, ' ');
1248
1249 /* The comment */
1250 trace_seq_puts(s, "/* ");
1251
1252 switch (iter->ent->type) {
1253 case TRACE_BPUTS:
1254 ret = trace_print_bputs_msg_only(iter);
1255 if (ret != TRACE_TYPE_HANDLED)
1256 return ret;
1257 break;
1258 case TRACE_BPRINT:
1259 ret = trace_print_bprintk_msg_only(iter);
1260 if (ret != TRACE_TYPE_HANDLED)
1261 return ret;
1262 break;
1263 case TRACE_PRINT:
1264 ret = trace_print_printk_msg_only(iter);
1265 if (ret != TRACE_TYPE_HANDLED)
1266 return ret;
1267 break;
1268 default:
1269 event = ftrace_find_event(ent->type);
1270 if (!event)
1271 return TRACE_TYPE_UNHANDLED;
1272
1273 ret = event->funcs->trace(iter, sym_flags, event);
1274 if (ret != TRACE_TYPE_HANDLED)
1275 return ret;
1276 }
1277
1278 if (trace_seq_has_overflowed(s))
1279 goto out;
1280
1281 /* Strip ending newline */
1282 if (s->buffer[s->seq.len - 1] == '\n') {
1283 s->buffer[s->seq.len - 1] = '\0';
1284 s->seq.len--;
1285 }
1286
1287 trace_seq_puts(s, " */\n");
1288 out:
1289 return trace_handle_return(s);
1290}
1291
1292
1293enum print_line_t
1294print_graph_function_flags(struct trace_iterator *iter, u32 flags)
1295{
1296 struct ftrace_graph_ent_entry *field;
1297 struct fgraph_data *data = iter->private;
1298 struct trace_entry *entry = iter->ent;
1299 struct trace_seq *s = &iter->seq;
1300 int cpu = iter->cpu;
1301 int ret;
1302
1303 if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
1304 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
1305 return TRACE_TYPE_HANDLED;
1306 }
1307
1308 /*
1309 * If the last output failed, there's a possibility we need
1310 * to print out the missing entry which would never go out.
1311 */
1312 if (data && data->failed) {
1313 field = &data->ent.ent;
1314 iter->cpu = data->cpu;
1315 ret = print_graph_entry(field, s, iter, flags);
1316 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) {
1317 per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1;
1318 ret = TRACE_TYPE_NO_CONSUME;
1319 }
1320 iter->cpu = cpu;
1321 return ret;
1322 }
1323
1324 switch (entry->type) {
1325 case TRACE_GRAPH_ENT: {
1326 /*
1327 * print_graph_entry() may consume the current event,
1328 * thus @field may become invalid, so we need to save it.
1329 * sizeof(struct ftrace_graph_ent_entry) is very small,
1330 * it can be safely saved at the stack.
1331 */
1332 struct ftrace_graph_ent_entry saved;
1333 trace_assign_type(field, entry);
1334 saved = *field;
1335 return print_graph_entry(&saved, s, iter, flags);
1336 }
1337#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
1338 case TRACE_GRAPH_RETADDR_ENT: {
1339 struct fgraph_retaddr_ent_entry saved;
1340 struct fgraph_retaddr_ent_entry *rfield;
1341
1342 trace_assign_type(rfield, entry);
1343 saved = *rfield;
1344 return print_graph_entry((struct ftrace_graph_ent_entry *)&saved, s, iter, flags);
1345 }
1346#endif
1347 case TRACE_GRAPH_RET: {
1348 struct ftrace_graph_ret_entry *field;
1349 trace_assign_type(field, entry);
1350 return print_graph_return(&field->ret, s, entry, iter, flags);
1351 }
1352 case TRACE_STACK:
1353 case TRACE_FN:
1354 /* dont trace stack and functions as comments */
1355 return TRACE_TYPE_UNHANDLED;
1356
1357 default:
1358 return print_graph_comment(s, entry, iter, flags);
1359 }
1360
1361 return TRACE_TYPE_HANDLED;
1362}
1363
1364static enum print_line_t
1365print_graph_function(struct trace_iterator *iter)
1366{
1367 return print_graph_function_flags(iter, tracer_flags.val);
1368}
1369
1370static enum print_line_t
1371print_graph_function_event(struct trace_iterator *iter, int flags,
1372 struct trace_event *event)
1373{
1374 return print_graph_function(iter);
1375}
1376
1377static void print_lat_header(struct seq_file *s, u32 flags)
1378{
1379 static const char spaces[] = " " /* 16 spaces */
1380 " " /* 4 spaces */
1381 " "; /* 17 spaces */
1382 int size = 0;
1383
1384 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1385 size += 16;
1386 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1387 size += 16;
1388 if (flags & TRACE_GRAPH_PRINT_CPU)
1389 size += 4;
1390 if (flags & TRACE_GRAPH_PRINT_PROC)
1391 size += 17;
1392
1393 seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces);
1394 seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces);
1395 seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces);
1396 seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces);
1397 seq_printf(s, "#%.*s||| / \n", size, spaces);
1398}
1399
1400static void __print_graph_headers_flags(struct trace_array *tr,
1401 struct seq_file *s, u32 flags)
1402{
1403 int lat = tr->trace_flags & TRACE_ITER_LATENCY_FMT;
1404
1405 if (lat)
1406 print_lat_header(s, flags);
1407
1408 /* 1st line */
1409 seq_putc(s, '#');
1410 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1411 seq_puts(s, " TIME ");
1412 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1413 seq_puts(s, " REL TIME ");
1414 if (flags & TRACE_GRAPH_PRINT_CPU)
1415 seq_puts(s, " CPU");
1416 if (flags & TRACE_GRAPH_PRINT_PROC)
1417 seq_puts(s, " TASK/PID ");
1418 if (lat)
1419 seq_puts(s, "|||| ");
1420 if (flags & TRACE_GRAPH_PRINT_DURATION)
1421 seq_puts(s, " DURATION ");
1422 seq_puts(s, " FUNCTION CALLS\n");
1423
1424 /* 2nd line */
1425 seq_putc(s, '#');
1426 if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
1427 seq_puts(s, " | ");
1428 if (flags & TRACE_GRAPH_PRINT_REL_TIME)
1429 seq_puts(s, " | ");
1430 if (flags & TRACE_GRAPH_PRINT_CPU)
1431 seq_puts(s, " | ");
1432 if (flags & TRACE_GRAPH_PRINT_PROC)
1433 seq_puts(s, " | | ");
1434 if (lat)
1435 seq_puts(s, "|||| ");
1436 if (flags & TRACE_GRAPH_PRINT_DURATION)
1437 seq_puts(s, " | | ");
1438 seq_puts(s, " | | | |\n");
1439}
1440
1441static void print_graph_headers(struct seq_file *s)
1442{
1443 print_graph_headers_flags(s, tracer_flags.val);
1444}
1445
1446void print_graph_headers_flags(struct seq_file *s, u32 flags)
1447{
1448 struct trace_iterator *iter = s->private;
1449 struct trace_array *tr = iter->tr;
1450
1451 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO))
1452 return;
1453
1454 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) {
1455 /* print nothing if the buffers are empty */
1456 if (trace_empty(iter))
1457 return;
1458
1459 print_trace_header(s, iter);
1460 }
1461
1462 __print_graph_headers_flags(tr, s, flags);
1463}
1464
1465void graph_trace_open(struct trace_iterator *iter)
1466{
1467 /* pid and depth on the last trace processed */
1468 struct fgraph_data *data;
1469 gfp_t gfpflags;
1470 int cpu;
1471
1472 iter->private = NULL;
1473
1474 /* We can be called in atomic context via ftrace_dump() */
1475 gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL;
1476
1477 data = kzalloc(sizeof(*data), gfpflags);
1478 if (!data)
1479 goto out_err;
1480
1481 data->cpu_data = alloc_percpu_gfp(struct fgraph_cpu_data, gfpflags);
1482 if (!data->cpu_data)
1483 goto out_err_free;
1484
1485 for_each_possible_cpu(cpu) {
1486 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
1487 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
1488 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
1489 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
1490
1491 *pid = -1;
1492 *depth = 0;
1493 *ignore = 0;
1494 *depth_irq = -1;
1495 }
1496
1497 iter->private = data;
1498
1499 return;
1500
1501 out_err_free:
1502 kfree(data);
1503 out_err:
1504 pr_warn("function graph tracer: not enough memory\n");
1505}
1506
1507void graph_trace_close(struct trace_iterator *iter)
1508{
1509 struct fgraph_data *data = iter->private;
1510
1511 if (data) {
1512 free_percpu(data->cpu_data);
1513 kfree(data);
1514 }
1515}
1516
1517static int
1518func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
1519{
1520 if (bit == TRACE_GRAPH_PRINT_IRQS)
1521 ftrace_graph_skip_irqs = !set;
1522
1523 if (bit == TRACE_GRAPH_SLEEP_TIME)
1524 ftrace_graph_sleep_time_control(set);
1525
1526 if (bit == TRACE_GRAPH_GRAPH_TIME)
1527 ftrace_graph_graph_time_control(set);
1528
1529 return 0;
1530}
1531
1532static struct trace_event_functions graph_functions = {
1533 .trace = print_graph_function_event,
1534};
1535
1536static struct trace_event graph_trace_entry_event = {
1537 .type = TRACE_GRAPH_ENT,
1538 .funcs = &graph_functions,
1539};
1540
1541#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
1542static struct trace_event graph_trace_retaddr_entry_event = {
1543 .type = TRACE_GRAPH_RETADDR_ENT,
1544 .funcs = &graph_functions,
1545};
1546#endif
1547
1548static struct trace_event graph_trace_ret_event = {
1549 .type = TRACE_GRAPH_RET,
1550 .funcs = &graph_functions
1551};
1552
1553static struct tracer graph_trace __tracer_data = {
1554 .name = "function_graph",
1555 .update_thresh = graph_trace_update_thresh,
1556 .open = graph_trace_open,
1557 .pipe_open = graph_trace_open,
1558 .close = graph_trace_close,
1559 .pipe_close = graph_trace_close,
1560 .init = graph_trace_init,
1561 .reset = graph_trace_reset,
1562 .print_line = print_graph_function,
1563 .print_header = print_graph_headers,
1564 .flags = &tracer_flags,
1565 .set_flag = func_graph_set_flag,
1566 .allow_instances = true,
1567#ifdef CONFIG_FTRACE_SELFTEST
1568 .selftest = trace_selftest_startup_function_graph,
1569#endif
1570};
1571
1572
1573static ssize_t
1574graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
1575 loff_t *ppos)
1576{
1577 unsigned long val;
1578 int ret;
1579
1580 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1581 if (ret)
1582 return ret;
1583
1584 fgraph_max_depth = val;
1585
1586 *ppos += cnt;
1587
1588 return cnt;
1589}
1590
1591static ssize_t
1592graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
1593 loff_t *ppos)
1594{
1595 char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/
1596 int n;
1597
1598 n = sprintf(buf, "%d\n", fgraph_max_depth);
1599
1600 return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
1601}
1602
1603static const struct file_operations graph_depth_fops = {
1604 .open = tracing_open_generic,
1605 .write = graph_depth_write,
1606 .read = graph_depth_read,
1607 .llseek = generic_file_llseek,
1608};
1609
1610static __init int init_graph_tracefs(void)
1611{
1612 int ret;
1613
1614 ret = tracing_init_dentry();
1615 if (ret)
1616 return 0;
1617
1618 trace_create_file("max_graph_depth", TRACE_MODE_WRITE, NULL,
1619 NULL, &graph_depth_fops);
1620
1621 return 0;
1622}
1623fs_initcall(init_graph_tracefs);
1624
1625static __init int init_graph_trace(void)
1626{
1627 max_bytes_for_cpu = snprintf(NULL, 0, "%u", nr_cpu_ids - 1);
1628
1629 if (!register_trace_event(&graph_trace_entry_event)) {
1630 pr_warn("Warning: could not register graph trace events\n");
1631 return 1;
1632 }
1633
1634#ifdef CONFIG_FUNCTION_GRAPH_RETADDR
1635 if (!register_trace_event(&graph_trace_retaddr_entry_event)) {
1636 pr_warn("Warning: could not register graph trace retaddr events\n");
1637 return 1;
1638 }
1639#endif
1640
1641 if (!register_trace_event(&graph_trace_ret_event)) {
1642 pr_warn("Warning: could not register graph trace events\n");
1643 return 1;
1644 }
1645
1646 return register_tracer(&graph_trace);
1647}
1648
1649core_initcall(init_graph_trace);