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-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/trace/Kconfig5
-rw-r--r--kernel/trace/Makefile2
-rw-r--r--kernel/trace/trace.c1547
-rw-r--r--kernel/trace/trace.h184
5 files changed, 1739 insertions, 0 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index fa05f6d8bdbf..7e344e7b0cb3 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
70obj-$(CONFIG_MARKERS) += marker.o 70obj-$(CONFIG_MARKERS) += marker.o
71obj-$(CONFIG_LATENCYTOP) += latencytop.o 71obj-$(CONFIG_LATENCYTOP) += latencytop.o
72obj-$(CONFIG_FTRACE) += trace/ 72obj-$(CONFIG_FTRACE) += trace/
73obj-$(CONFIG_TRACING) += trace/
73 74
74ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) 75ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
75# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is 76# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 8185c91417bc..ce70677afbf9 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -3,3 +3,8 @@
3# 3#
4config HAVE_FTRACE 4config HAVE_FTRACE
5 bool 5 bool
6
7config TRACING
8 bool
9 select DEBUG_FS
10
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index bf4fd215a6a9..7af403175255 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -1,3 +1,5 @@
1obj-$(CONFIG_FTRACE) += libftrace.o 1obj-$(CONFIG_FTRACE) += libftrace.o
2 2
3obj-$(CONFIG_TRACING) += trace.o
4
3libftrace-y := ftrace.o 5libftrace-y := ftrace.o
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
new file mode 100644
index 000000000000..1b8eca7650d4
--- /dev/null
+++ b/kernel/trace/trace.c
@@ -0,0 +1,1547 @@
1/*
2 * ring buffer based function tracer
3 *
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
6 *
7 * Originally taken from the RT patch by:
8 * Arnaldo Carvalho de Melo <acme@redhat.com>
9 *
10 * Based on code from the latency_tracer, that is:
11 * Copyright (C) 2004-2006 Ingo Molnar
12 * Copyright (C) 2004 William Lee Irwin III
13 */
14#include <linux/utsrelease.h>
15#include <linux/kallsyms.h>
16#include <linux/seq_file.h>
17#include <linux/debugfs.h>
18#include <linux/hardirq.h>
19#include <linux/linkage.h>
20#include <linux/uaccess.h>
21#include <linux/ftrace.h>
22#include <linux/module.h>
23#include <linux/percpu.h>
24#include <linux/ctype.h>
25#include <linux/init.h>
26#include <linux/gfp.h>
27#include <linux/fs.h>
28
29#include "trace.h"
30
31unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
32unsigned long __read_mostly tracing_thresh;
33
34static long notrace
35ns2usecs(cycle_t nsec)
36{
37 nsec += 500;
38 do_div(nsec, 1000);
39 return nsec;
40}
41
42static atomic_t tracer_counter;
43static struct trace_array global_trace;
44
45static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
46
47static struct trace_array max_tr;
48
49static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
50
51static int tracer_enabled;
52static unsigned long trace_nr_entries = 4096UL;
53
54static struct tracer *trace_types __read_mostly;
55static struct tracer *current_trace __read_mostly;
56static int max_tracer_type_len;
57
58static DEFINE_MUTEX(trace_types_lock);
59
60static int __init set_nr_entries(char *str)
61{
62 if (!str)
63 return 0;
64 trace_nr_entries = simple_strtoul(str, &str, 0);
65 return 1;
66}
67__setup("trace_entries=", set_nr_entries);
68
69enum trace_type {
70 __TRACE_FIRST_TYPE = 0,
71
72 TRACE_FN,
73 TRACE_CTX,
74
75 __TRACE_LAST_TYPE
76};
77
78enum trace_flag_type {
79 TRACE_FLAG_IRQS_OFF = 0x01,
80 TRACE_FLAG_NEED_RESCHED = 0x02,
81 TRACE_FLAG_HARDIRQ = 0x04,
82 TRACE_FLAG_SOFTIRQ = 0x08,
83};
84
85enum trace_iterator_flags {
86 TRACE_ITER_PRINT_PARENT = 0x01,
87 TRACE_ITER_SYM_OFFSET = 0x02,
88 TRACE_ITER_SYM_ADDR = 0x04,
89 TRACE_ITER_VERBOSE = 0x08,
90};
91
92#define TRACE_ITER_SYM_MASK \
93 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
94
95/* These must match the bit postions above */
96static const char *trace_options[] = {
97 "print-parent",
98 "sym-offset",
99 "sym-addr",
100 "verbose",
101 NULL
102};
103
104static unsigned trace_flags;
105
106
107/*
108 * Copy the new maximum trace into the separate maximum-trace
109 * structure. (this way the maximum trace is permanently saved,
110 * for later retrieval via /debugfs/tracing/latency_trace)
111 */
112static void notrace
113__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
114{
115 struct trace_array_cpu *data = tr->data[cpu];
116
117 max_tr.cpu = cpu;
118 max_tr.time_start = data->preempt_timestamp;
119
120 data = max_tr.data[cpu];
121 data->saved_latency = tracing_max_latency;
122
123 memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
124 data->pid = tsk->pid;
125 data->uid = tsk->uid;
126 data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
127 data->policy = tsk->policy;
128 data->rt_priority = tsk->rt_priority;
129
130 /* record this tasks comm */
131 tracing_record_cmdline(current);
132}
133
134notrace void
135update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
136{
137 struct trace_array_cpu *data;
138 void *save_trace;
139 int i;
140
141 /* clear out all the previous traces */
142 for_each_possible_cpu(i) {
143 data = tr->data[i];
144 save_trace = max_tr.data[i]->trace;
145 memcpy(max_tr.data[i], data, sizeof(*data));
146 data->trace = save_trace;
147 }
148
149 __update_max_tr(tr, tsk, cpu);
150}
151
152/**
153 * update_max_tr_single - only copy one trace over, and reset the rest
154 * @tr - tracer
155 * @tsk - task with the latency
156 * @cpu - the cpu of the buffer to copy.
157 */
158notrace void
159update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
160{
161 struct trace_array_cpu *data = tr->data[cpu];
162 void *save_trace;
163 int i;
164
165 for_each_possible_cpu(i)
166 tracing_reset(max_tr.data[i]);
167
168 save_trace = max_tr.data[cpu]->trace;
169 memcpy(max_tr.data[cpu], data, sizeof(*data));
170 data->trace = save_trace;
171
172 __update_max_tr(tr, tsk, cpu);
173}
174
175int register_tracer(struct tracer *type)
176{
177 struct tracer *t;
178 int len;
179 int ret = 0;
180
181 if (!type->name) {
182 pr_info("Tracer must have a name\n");
183 return -1;
184 }
185
186 mutex_lock(&trace_types_lock);
187 for (t = trace_types; t; t = t->next) {
188 if (strcmp(type->name, t->name) == 0) {
189 /* already found */
190 pr_info("Trace %s already registered\n",
191 type->name);
192 ret = -1;
193 goto out;
194 }
195 }
196
197 type->next = trace_types;
198 trace_types = type;
199 len = strlen(type->name);
200 if (len > max_tracer_type_len)
201 max_tracer_type_len = len;
202 out:
203 mutex_unlock(&trace_types_lock);
204
205 return ret;
206}
207
208void unregister_tracer(struct tracer *type)
209{
210 struct tracer **t;
211 int len;
212
213 mutex_lock(&trace_types_lock);
214 for (t = &trace_types; *t; t = &(*t)->next) {
215 if (*t == type)
216 goto found;
217 }
218 pr_info("Trace %s not registered\n", type->name);
219 goto out;
220
221 found:
222 *t = (*t)->next;
223 if (strlen(type->name) != max_tracer_type_len)
224 goto out;
225
226 max_tracer_type_len = 0;
227 for (t = &trace_types; *t; t = &(*t)->next) {
228 len = strlen((*t)->name);
229 if (len > max_tracer_type_len)
230 max_tracer_type_len = len;
231 }
232 out:
233 mutex_unlock(&trace_types_lock);
234}
235
236void notrace tracing_reset(struct trace_array_cpu *data)
237{
238 data->trace_idx = 0;
239 atomic_set(&data->underrun, 0);
240}
241
242#ifdef CONFIG_FTRACE
243static void notrace
244function_trace_call(unsigned long ip, unsigned long parent_ip)
245{
246 struct trace_array *tr = &global_trace;
247 struct trace_array_cpu *data;
248 unsigned long flags;
249 long disabled;
250 int cpu;
251
252 if (unlikely(!tracer_enabled))
253 return;
254
255 raw_local_irq_save(flags);
256 cpu = raw_smp_processor_id();
257 data = tr->data[cpu];
258 disabled = atomic_inc_return(&data->disabled);
259
260 if (likely(disabled == 1))
261 ftrace(tr, data, ip, parent_ip, flags);
262
263 atomic_dec(&data->disabled);
264 raw_local_irq_restore(flags);
265}
266
267static struct ftrace_ops trace_ops __read_mostly =
268{
269 .func = function_trace_call,
270};
271#endif
272
273notrace void tracing_start_function_trace(void)
274{
275 register_ftrace_function(&trace_ops);
276}
277
278notrace void tracing_stop_function_trace(void)
279{
280 unregister_ftrace_function(&trace_ops);
281}
282
283#define SAVED_CMDLINES 128
284static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
285static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
286static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
287static int cmdline_idx;
288static DEFINE_SPINLOCK(trace_cmdline_lock);
289atomic_t trace_record_cmdline_disabled;
290
291static void trace_init_cmdlines(void)
292{
293 memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline));
294 memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid));
295 cmdline_idx = 0;
296}
297
298notrace void trace_stop_cmdline_recording(void);
299
300static void notrace trace_save_cmdline(struct task_struct *tsk)
301{
302 unsigned map;
303 unsigned idx;
304
305 if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
306 return;
307
308 /*
309 * It's not the end of the world if we don't get
310 * the lock, but we also don't want to spin
311 * nor do we want to disable interrupts,
312 * so if we miss here, then better luck next time.
313 */
314 if (!spin_trylock(&trace_cmdline_lock))
315 return;
316
317 idx = map_pid_to_cmdline[tsk->pid];
318 if (idx >= SAVED_CMDLINES) {
319 idx = (cmdline_idx + 1) % SAVED_CMDLINES;
320
321 map = map_cmdline_to_pid[idx];
322 if (map <= PID_MAX_DEFAULT)
323 map_pid_to_cmdline[map] = (unsigned)-1;
324
325 map_pid_to_cmdline[tsk->pid] = idx;
326
327 cmdline_idx = idx;
328 }
329
330 memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
331
332 spin_unlock(&trace_cmdline_lock);
333}
334
335static notrace char *trace_find_cmdline(int pid)
336{
337 char *cmdline = "<...>";
338 unsigned map;
339
340 if (!pid)
341 return "<idle>";
342
343 if (pid > PID_MAX_DEFAULT)
344 goto out;
345
346 map = map_pid_to_cmdline[pid];
347 if (map >= SAVED_CMDLINES)
348 goto out;
349
350 cmdline = saved_cmdlines[map];
351
352 out:
353 return cmdline;
354}
355
356notrace void tracing_record_cmdline(struct task_struct *tsk)
357{
358 if (atomic_read(&trace_record_cmdline_disabled))
359 return;
360
361 trace_save_cmdline(tsk);
362}
363
364static inline notrace struct trace_entry *
365tracing_get_trace_entry(struct trace_array *tr,
366 struct trace_array_cpu *data)
367{
368 unsigned long idx, idx_next;
369 struct trace_entry *entry;
370
371 idx = data->trace_idx;
372 idx_next = idx + 1;
373
374 if (unlikely(idx_next >= tr->entries)) {
375 atomic_inc(&data->underrun);
376 idx_next = 0;
377 }
378
379 data->trace_idx = idx_next;
380
381 if (unlikely(idx_next != 0 && atomic_read(&data->underrun)))
382 atomic_inc(&data->underrun);
383
384 entry = data->trace + idx * TRACE_ENTRY_SIZE;
385
386 return entry;
387}
388
389static inline notrace void
390tracing_generic_entry_update(struct trace_entry *entry,
391 unsigned long flags)
392{
393 struct task_struct *tsk = current;
394 unsigned long pc;
395
396 pc = preempt_count();
397
398 entry->idx = atomic_inc_return(&tracer_counter);
399 entry->preempt_count = pc & 0xff;
400 entry->pid = tsk->pid;
401 entry->t = now(raw_smp_processor_id());
402 entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
403 ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
404 ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
405 (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
406}
407
408notrace void
409ftrace(struct trace_array *tr, struct trace_array_cpu *data,
410 unsigned long ip, unsigned long parent_ip,
411 unsigned long flags)
412{
413 struct trace_entry *entry;
414
415 entry = tracing_get_trace_entry(tr, data);
416 tracing_generic_entry_update(entry, flags);
417 entry->type = TRACE_FN;
418 entry->fn.ip = ip;
419 entry->fn.parent_ip = parent_ip;
420}
421
422notrace void
423tracing_sched_switch_trace(struct trace_array *tr,
424 struct trace_array_cpu *data,
425 struct task_struct *prev, struct task_struct *next,
426 unsigned long flags)
427{
428 struct trace_entry *entry;
429
430 entry = tracing_get_trace_entry(tr, data);
431 tracing_generic_entry_update(entry, flags);
432 entry->type = TRACE_CTX;
433 entry->ctx.prev_pid = prev->pid;
434 entry->ctx.prev_prio = prev->prio;
435 entry->ctx.prev_state = prev->state;
436 entry->ctx.next_pid = next->pid;
437 entry->ctx.next_prio = next->prio;
438}
439
440enum trace_file_type {
441 TRACE_FILE_LAT_FMT = 1,
442};
443
444static struct trace_entry *
445trace_entry_idx(struct trace_array *tr, unsigned long idx, int cpu)
446{
447 struct trace_entry *array = tr->data[cpu]->trace;
448 unsigned long underrun;
449
450 if (idx >= tr->entries)
451 return NULL;
452
453 underrun = atomic_read(&tr->data[cpu]->underrun);
454 if (underrun)
455 idx = ((underrun - 1) + idx) % tr->entries;
456 else if (idx >= tr->data[cpu]->trace_idx)
457 return NULL;
458
459 return &array[idx];
460}
461
462static struct notrace trace_entry *
463find_next_entry(struct trace_iterator *iter, int *ent_cpu)
464{
465 struct trace_array *tr = iter->tr;
466 struct trace_entry *ent, *next = NULL;
467 int next_cpu = -1;
468 int cpu;
469
470 for_each_possible_cpu(cpu) {
471 if (!tr->data[cpu]->trace)
472 continue;
473 ent = trace_entry_idx(tr, iter->next_idx[cpu], cpu);
474 if (ent &&
475 (!next || (long)(next->idx - ent->idx) > 0)) {
476 next = ent;
477 next_cpu = cpu;
478 }
479 }
480
481 if (ent_cpu)
482 *ent_cpu = next_cpu;
483
484 return next;
485}
486
487static void *find_next_entry_inc(struct trace_iterator *iter)
488{
489 struct trace_entry *next;
490 int next_cpu = -1;
491
492 next = find_next_entry(iter, &next_cpu);
493
494 if (next) {
495 iter->next_idx[next_cpu]++;
496 iter->idx++;
497 }
498 iter->ent = next;
499 iter->cpu = next_cpu;
500
501 return next ? iter : NULL;
502}
503
504static void notrace *
505s_next(struct seq_file *m, void *v, loff_t *pos)
506{
507 struct trace_iterator *iter = m->private;
508 void *ent;
509 void *last_ent = iter->ent;
510 int i = (int)*pos;
511
512 (*pos)++;
513
514 /* can't go backwards */
515 if (iter->idx > i)
516 return NULL;
517
518 if (iter->idx < 0)
519 ent = find_next_entry_inc(iter);
520 else
521 ent = iter;
522
523 while (ent && iter->idx < i)
524 ent = find_next_entry_inc(iter);
525
526 iter->pos = *pos;
527
528 if (last_ent && !ent)
529 seq_puts(m, "\n\nvim:ft=help\n");
530
531 return ent;
532}
533
534static void *s_start(struct seq_file *m, loff_t *pos)
535{
536 struct trace_iterator *iter = m->private;
537 void *p = NULL;
538 loff_t l = 0;
539 int i;
540
541 mutex_lock(&trace_types_lock);
542
543 if (!current_trace || current_trace != iter->trace)
544 return NULL;
545
546 atomic_inc(&trace_record_cmdline_disabled);
547
548 /* let the tracer grab locks here if needed */
549 if (current_trace->start)
550 current_trace->start(iter);
551
552 if (*pos != iter->pos) {
553 iter->ent = NULL;
554 iter->cpu = 0;
555 iter->idx = -1;
556
557 for (i = 0; i < NR_CPUS; i++)
558 iter->next_idx[i] = 0;
559
560 for (p = iter; p && l < *pos; p = s_next(m, p, &l))
561 ;
562
563 } else {
564 l = *pos;
565 p = s_next(m, p, &l);
566 }
567
568 return p;
569}
570
571static void s_stop(struct seq_file *m, void *p)
572{
573 struct trace_iterator *iter = m->private;
574
575 atomic_dec(&trace_record_cmdline_disabled);
576
577 /* let the tracer release locks here if needed */
578 if (current_trace && current_trace == iter->trace && iter->trace->stop)
579 iter->trace->stop(iter);
580
581 mutex_unlock(&trace_types_lock);
582}
583
584static void
585seq_print_sym_short(struct seq_file *m, const char *fmt, unsigned long address)
586{
587#ifdef CONFIG_KALLSYMS
588 char str[KSYM_SYMBOL_LEN];
589
590 kallsyms_lookup(address, NULL, NULL, NULL, str);
591
592 seq_printf(m, fmt, str);
593#endif
594}
595
596static void
597seq_print_sym_offset(struct seq_file *m, const char *fmt, unsigned long address)
598{
599#ifdef CONFIG_KALLSYMS
600 char str[KSYM_SYMBOL_LEN];
601
602 sprint_symbol(str, address);
603 seq_printf(m, fmt, str);
604#endif
605}
606
607#ifndef CONFIG_64BIT
608# define IP_FMT "%08lx"
609#else
610# define IP_FMT "%016lx"
611#endif
612
613static void notrace
614seq_print_ip_sym(struct seq_file *m, unsigned long ip, unsigned long sym_flags)
615{
616 if (!ip) {
617 seq_printf(m, "0");
618 return;
619 }
620
621 if (sym_flags & TRACE_ITER_SYM_OFFSET)
622 seq_print_sym_offset(m, "%s", ip);
623 else
624 seq_print_sym_short(m, "%s", ip);
625
626 if (sym_flags & TRACE_ITER_SYM_ADDR)
627 seq_printf(m, " <" IP_FMT ">", ip);
628}
629
630static void notrace print_lat_help_header(struct seq_file *m)
631{
632 seq_puts(m, "# _------=> CPU# \n");
633 seq_puts(m, "# / _-----=> irqs-off \n");
634 seq_puts(m, "# | / _----=> need-resched \n");
635 seq_puts(m, "# || / _---=> hardirq/softirq \n");
636 seq_puts(m, "# ||| / _--=> preempt-depth \n");
637 seq_puts(m, "# |||| / \n");
638 seq_puts(m, "# ||||| delay \n");
639 seq_puts(m, "# cmd pid ||||| time | caller \n");
640 seq_puts(m, "# \\ / ||||| \\ | / \n");
641}
642
643static void notrace print_func_help_header(struct seq_file *m)
644{
645 seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
646 seq_puts(m, "# | | | | |\n");
647}
648
649
650static void notrace
651print_trace_header(struct seq_file *m, struct trace_iterator *iter)
652{
653 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
654 struct trace_array *tr = iter->tr;
655 struct trace_array_cpu *data = tr->data[tr->cpu];
656 struct tracer *type = current_trace;
657 unsigned long underruns = 0;
658 unsigned long underrun;
659 unsigned long entries = 0;
660 int cpu;
661 const char *name = "preemption";
662
663 if (type)
664 name = type->name;
665
666 for_each_possible_cpu(cpu) {
667 if (tr->data[cpu]->trace) {
668 underrun = atomic_read(&tr->data[cpu]->underrun);
669 if (underrun) {
670 underruns += underrun;
671 entries += tr->entries;
672 } else
673 entries += tr->data[cpu]->trace_idx;
674 }
675 }
676
677 seq_printf(m, "%s latency trace v1.1.5 on %s\n",
678 name, UTS_RELEASE);
679 seq_puts(m, "-----------------------------------"
680 "---------------------------------\n");
681 seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |"
682 " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
683 data->saved_latency,
684 entries,
685 (entries + underruns),
686 tr->cpu,
687#if defined(CONFIG_PREEMPT_NONE)
688 "server",
689#elif defined(CONFIG_PREEMPT_VOLUNTARY)
690 "desktop",
691#elif defined(CONFIG_PREEMPT_DESKTOP)
692 "preempt",
693#else
694 "unknown",
695#endif
696 /* These are reserved for later use */
697 0, 0, 0, 0);
698#ifdef CONFIG_SMP
699 seq_printf(m, " #P:%d)\n", num_online_cpus());
700#else
701 seq_puts(m, ")\n");
702#endif
703 seq_puts(m, " -----------------\n");
704 seq_printf(m, " | task: %.16s-%d "
705 "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
706 data->comm, data->pid, data->uid, data->nice,
707 data->policy, data->rt_priority);
708 seq_puts(m, " -----------------\n");
709
710 if (data->critical_start) {
711 seq_puts(m, " => started at: ");
712 seq_print_ip_sym(m, data->critical_start, sym_flags);
713 seq_puts(m, "\n => ended at: ");
714 seq_print_ip_sym(m, data->critical_end, sym_flags);
715 seq_puts(m, "\n");
716 }
717
718 seq_puts(m, "\n");
719}
720
721unsigned long nsecs_to_usecs(unsigned long nsecs)
722{
723 return nsecs / 1000;
724}
725
726static void notrace
727lat_print_generic(struct seq_file *m, struct trace_entry *entry, int cpu)
728{
729 int hardirq, softirq;
730 char *comm;
731
732 comm = trace_find_cmdline(entry->pid);
733
734 seq_printf(m, "%8.8s-%-5d ", comm, entry->pid);
735 seq_printf(m, "%d", cpu);
736 seq_printf(m, "%c%c",
737 (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
738 ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
739
740 hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
741 softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
742 if (hardirq && softirq)
743 seq_putc(m, 'H');
744 else {
745 if (hardirq)
746 seq_putc(m, 'h');
747 else {
748 if (softirq)
749 seq_putc(m, 's');
750 else
751 seq_putc(m, '.');
752 }
753 }
754
755 if (entry->preempt_count)
756 seq_printf(m, "%x", entry->preempt_count);
757 else
758 seq_puts(m, ".");
759}
760
761unsigned long preempt_mark_thresh = 100;
762
763static void notrace
764lat_print_timestamp(struct seq_file *m, unsigned long long abs_usecs,
765 unsigned long rel_usecs)
766{
767 seq_printf(m, " %4lldus", abs_usecs);
768 if (rel_usecs > preempt_mark_thresh)
769 seq_puts(m, "!: ");
770 else if (rel_usecs > 1)
771 seq_puts(m, "+: ");
772 else
773 seq_puts(m, " : ");
774}
775
776static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
777
778static void notrace
779print_lat_fmt(struct seq_file *m, struct trace_iterator *iter,
780 unsigned int trace_idx, int cpu)
781{
782 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
783 struct trace_entry *next_entry = find_next_entry(iter, NULL);
784 unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
785 struct trace_entry *entry = iter->ent;
786 unsigned long abs_usecs;
787 unsigned long rel_usecs;
788 char *comm;
789 int S;
790
791 if (!next_entry)
792 next_entry = entry;
793 rel_usecs = ns2usecs(next_entry->t - entry->t);
794 abs_usecs = ns2usecs(entry->t - iter->tr->time_start);
795
796 if (verbose) {
797 comm = trace_find_cmdline(entry->pid);
798 seq_printf(m, "%16s %5d %d %d %08x %08x [%08lx]"
799 " %ld.%03ldms (+%ld.%03ldms): ",
800 comm,
801 entry->pid, cpu, entry->flags,
802 entry->preempt_count, trace_idx,
803 ns2usecs(entry->t),
804 abs_usecs/1000,
805 abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000);
806 } else {
807 lat_print_generic(m, entry, cpu);
808 lat_print_timestamp(m, abs_usecs, rel_usecs);
809 }
810 switch (entry->type) {
811 case TRACE_FN:
812 seq_print_ip_sym(m, entry->fn.ip, sym_flags);
813 seq_puts(m, " (");
814 seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags);
815 seq_puts(m, ")\n");
816 break;
817 case TRACE_CTX:
818 S = entry->ctx.prev_state < sizeof(state_to_char) ?
819 state_to_char[entry->ctx.prev_state] : 'X';
820 comm = trace_find_cmdline(entry->ctx.next_pid);
821 seq_printf(m, " %d:%d:%c --> %d:%d %s\n",
822 entry->ctx.prev_pid,
823 entry->ctx.prev_prio,
824 S,
825 entry->ctx.next_pid,
826 entry->ctx.next_prio,
827 comm);
828 break;
829 }
830}
831
832static void notrace
833print_trace_fmt(struct seq_file *m, struct trace_iterator *iter)
834{
835 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
836 struct trace_entry *entry = iter->ent;
837 unsigned long usec_rem;
838 unsigned long long t;
839 unsigned long secs;
840 char *comm;
841 int S;
842
843 comm = trace_find_cmdline(iter->ent->pid);
844
845 t = ns2usecs(entry->t);
846 usec_rem = do_div(t, 1000000ULL);
847 secs = (unsigned long)t;
848
849 seq_printf(m, "%16s-%-5d ", comm, entry->pid);
850 seq_printf(m, "[%02d] ", iter->cpu);
851 seq_printf(m, "%5lu.%06lu: ", secs, usec_rem);
852
853 switch (entry->type) {
854 case TRACE_FN:
855 seq_print_ip_sym(m, entry->fn.ip, sym_flags);
856 if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
857 entry->fn.parent_ip) {
858 seq_printf(m, " <-");
859 seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags);
860 }
861 break;
862 case TRACE_CTX:
863 S = entry->ctx.prev_state < sizeof(state_to_char) ?
864 state_to_char[entry->ctx.prev_state] : 'X';
865 seq_printf(m, " %d:%d:%c ==> %d:%d\n",
866 entry->ctx.prev_pid,
867 entry->ctx.prev_prio,
868 S,
869 entry->ctx.next_pid,
870 entry->ctx.next_prio);
871 break;
872 }
873 seq_printf(m, "\n");
874}
875
876static int trace_empty(struct trace_iterator *iter)
877{
878 struct trace_array_cpu *data;
879 int cpu;
880
881 for_each_possible_cpu(cpu) {
882 data = iter->tr->data[cpu];
883
884 if (data->trace &&
885 (data->trace_idx ||
886 atomic_read(&data->underrun)))
887 return 0;
888 }
889 return 1;
890}
891
892static int s_show(struct seq_file *m, void *v)
893{
894 struct trace_iterator *iter = v;
895
896 if (iter->ent == NULL) {
897 if (iter->tr) {
898 seq_printf(m, "# tracer: %s\n", iter->trace->name);
899 seq_puts(m, "#\n");
900 }
901 if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
902 /* print nothing if the buffers are empty */
903 if (trace_empty(iter))
904 return 0;
905 print_trace_header(m, iter);
906 if (!(trace_flags & TRACE_ITER_VERBOSE))
907 print_lat_help_header(m);
908 } else {
909 if (!(trace_flags & TRACE_ITER_VERBOSE))
910 print_func_help_header(m);
911 }
912 } else {
913 if (iter->iter_flags & TRACE_FILE_LAT_FMT)
914 print_lat_fmt(m, iter, iter->idx, iter->cpu);
915 else
916 print_trace_fmt(m, iter);
917 }
918
919 return 0;
920}
921
922static struct seq_operations tracer_seq_ops = {
923 .start = s_start,
924 .next = s_next,
925 .stop = s_stop,
926 .show = s_show,
927};
928
929static struct trace_iterator notrace *
930__tracing_open(struct inode *inode, struct file *file, int *ret)
931{
932 struct trace_iterator *iter;
933
934 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
935 if (!iter) {
936 *ret = -ENOMEM;
937 goto out;
938 }
939
940 mutex_lock(&trace_types_lock);
941 if (current_trace && current_trace->print_max)
942 iter->tr = &max_tr;
943 else
944 iter->tr = inode->i_private;
945 iter->trace = current_trace;
946 iter->pos = -1;
947
948 /* TODO stop tracer */
949 *ret = seq_open(file, &tracer_seq_ops);
950 if (!*ret) {
951 struct seq_file *m = file->private_data;
952 m->private = iter;
953
954 /* stop the trace while dumping */
955 if (iter->tr->ctrl)
956 tracer_enabled = 0;
957
958 if (iter->trace && iter->trace->open)
959 iter->trace->open(iter);
960 } else {
961 kfree(iter);
962 iter = NULL;
963 }
964 mutex_unlock(&trace_types_lock);
965
966 out:
967 return iter;
968}
969
970int tracing_open_generic(struct inode *inode, struct file *filp)
971{
972 filp->private_data = inode->i_private;
973 return 0;
974}
975
976int tracing_release(struct inode *inode, struct file *file)
977{
978 struct seq_file *m = (struct seq_file *)file->private_data;
979 struct trace_iterator *iter = m->private;
980
981 mutex_lock(&trace_types_lock);
982 if (iter->trace && iter->trace->close)
983 iter->trace->close(iter);
984
985 /* reenable tracing if it was previously enabled */
986 if (iter->tr->ctrl)
987 tracer_enabled = 1;
988 mutex_unlock(&trace_types_lock);
989
990 seq_release(inode, file);
991 kfree(iter);
992 return 0;
993}
994
995static int tracing_open(struct inode *inode, struct file *file)
996{
997 int ret;
998
999 __tracing_open(inode, file, &ret);
1000
1001 return ret;
1002}
1003
1004static int tracing_lt_open(struct inode *inode, struct file *file)
1005{
1006 struct trace_iterator *iter;
1007 int ret;
1008
1009 iter = __tracing_open(inode, file, &ret);
1010
1011 if (!ret)
1012 iter->iter_flags |= TRACE_FILE_LAT_FMT;
1013
1014 return ret;
1015}
1016
1017
1018static void notrace *
1019t_next(struct seq_file *m, void *v, loff_t *pos)
1020{
1021 struct tracer *t = m->private;
1022
1023 (*pos)++;
1024
1025 if (t)
1026 t = t->next;
1027
1028 m->private = t;
1029
1030 return t;
1031}
1032
1033static void *t_start(struct seq_file *m, loff_t *pos)
1034{
1035 struct tracer *t = m->private;
1036 loff_t l = 0;
1037
1038 mutex_lock(&trace_types_lock);
1039 for (; t && l < *pos; t = t_next(m, t, &l))
1040 ;
1041
1042 return t;
1043}
1044
1045static void t_stop(struct seq_file *m, void *p)
1046{
1047 mutex_unlock(&trace_types_lock);
1048}
1049
1050static int t_show(struct seq_file *m, void *v)
1051{
1052 struct tracer *t = v;
1053
1054 if (!t)
1055 return 0;
1056
1057 seq_printf(m, "%s", t->name);
1058 if (t->next)
1059 seq_putc(m, ' ');
1060 else
1061 seq_putc(m, '\n');
1062
1063 return 0;
1064}
1065
1066static struct seq_operations show_traces_seq_ops = {
1067 .start = t_start,
1068 .next = t_next,
1069 .stop = t_stop,
1070 .show = t_show,
1071};
1072
1073static int show_traces_open(struct inode *inode, struct file *file)
1074{
1075 int ret;
1076
1077 ret = seq_open(file, &show_traces_seq_ops);
1078 if (!ret) {
1079 struct seq_file *m = file->private_data;
1080 m->private = trace_types;
1081 }
1082
1083 return ret;
1084}
1085
1086static struct file_operations tracing_fops = {
1087 .open = tracing_open,
1088 .read = seq_read,
1089 .llseek = seq_lseek,
1090 .release = tracing_release,
1091};
1092
1093static struct file_operations tracing_lt_fops = {
1094 .open = tracing_lt_open,
1095 .read = seq_read,
1096 .llseek = seq_lseek,
1097 .release = tracing_release,
1098};
1099
1100static struct file_operations show_traces_fops = {
1101 .open = show_traces_open,
1102 .read = seq_read,
1103 .release = seq_release,
1104};
1105
1106static ssize_t
1107tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
1108 size_t cnt, loff_t *ppos)
1109{
1110 char *buf;
1111 int r = 0;
1112 int len = 0;
1113 int i;
1114
1115 /* calulate max size */
1116 for (i = 0; trace_options[i]; i++) {
1117 len += strlen(trace_options[i]);
1118 len += 3; /* "no" and space */
1119 }
1120
1121 /* +2 for \n and \0 */
1122 buf = kmalloc(len + 2, GFP_KERNEL);
1123 if (!buf)
1124 return -ENOMEM;
1125
1126 for (i = 0; trace_options[i]; i++) {
1127 if (trace_flags & (1 << i))
1128 r += sprintf(buf + r, "%s ", trace_options[i]);
1129 else
1130 r += sprintf(buf + r, "no%s ", trace_options[i]);
1131 }
1132
1133 r += sprintf(buf + r, "\n");
1134 WARN_ON(r >= len + 2);
1135
1136 r = simple_read_from_buffer(ubuf, cnt, ppos,
1137 buf, r);
1138
1139 kfree(buf);
1140
1141 return r;
1142}
1143
1144static ssize_t
1145tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
1146 size_t cnt, loff_t *ppos)
1147{
1148 char buf[64];
1149 char *cmp = buf;
1150 int neg = 0;
1151 int i;
1152
1153 if (cnt > 63)
1154 cnt = 63;
1155
1156 if (copy_from_user(&buf, ubuf, cnt))
1157 return -EFAULT;
1158
1159 buf[cnt] = 0;
1160
1161 if (strncmp(buf, "no", 2) == 0) {
1162 neg = 1;
1163 cmp += 2;
1164 }
1165
1166 for (i = 0; trace_options[i]; i++) {
1167 int len = strlen(trace_options[i]);
1168
1169 if (strncmp(cmp, trace_options[i], len) == 0) {
1170 if (neg)
1171 trace_flags &= ~(1 << i);
1172 else
1173 trace_flags |= (1 << i);
1174 break;
1175 }
1176 }
1177
1178 filp->f_pos += cnt;
1179
1180 return cnt;
1181}
1182
1183static struct file_operations tracing_iter_fops = {
1184 .open = tracing_open_generic,
1185 .read = tracing_iter_ctrl_read,
1186 .write = tracing_iter_ctrl_write,
1187};
1188
1189static ssize_t
1190tracing_ctrl_read(struct file *filp, char __user *ubuf,
1191 size_t cnt, loff_t *ppos)
1192{
1193 struct trace_array *tr = filp->private_data;
1194 char buf[64];
1195 int r;
1196
1197 r = sprintf(buf, "%ld\n", tr->ctrl);
1198 return simple_read_from_buffer(ubuf, cnt, ppos,
1199 buf, r);
1200}
1201
1202static ssize_t
1203tracing_ctrl_write(struct file *filp, const char __user *ubuf,
1204 size_t cnt, loff_t *ppos)
1205{
1206 struct trace_array *tr = filp->private_data;
1207 long val;
1208 char buf[64];
1209
1210 if (cnt > 63)
1211 cnt = 63;
1212
1213 if (copy_from_user(&buf, ubuf, cnt))
1214 return -EFAULT;
1215
1216 buf[cnt] = 0;
1217
1218 val = simple_strtoul(buf, NULL, 10);
1219
1220 val = !!val;
1221
1222 mutex_lock(&trace_types_lock);
1223 if (tr->ctrl ^ val) {
1224 if (val)
1225 tracer_enabled = 1;
1226 else
1227 tracer_enabled = 0;
1228
1229 tr->ctrl = val;
1230
1231 if (current_trace && current_trace->ctrl_update)
1232 current_trace->ctrl_update(tr);
1233 }
1234 mutex_unlock(&trace_types_lock);
1235
1236 filp->f_pos += cnt;
1237
1238 return cnt;
1239}
1240
1241static ssize_t
1242tracing_set_trace_read(struct file *filp, char __user *ubuf,
1243 size_t cnt, loff_t *ppos)
1244{
1245 char buf[max_tracer_type_len+2];
1246 int r;
1247
1248 mutex_lock(&trace_types_lock);
1249 if (current_trace)
1250 r = sprintf(buf, "%s\n", current_trace->name);
1251 else
1252 r = sprintf(buf, "\n");
1253 mutex_unlock(&trace_types_lock);
1254
1255 return simple_read_from_buffer(ubuf, cnt, ppos,
1256 buf, r);
1257}
1258
1259static ssize_t
1260tracing_set_trace_write(struct file *filp, const char __user *ubuf,
1261 size_t cnt, loff_t *ppos)
1262{
1263 struct trace_array *tr = &global_trace;
1264 struct tracer *t;
1265 char buf[max_tracer_type_len+1];
1266 int i;
1267
1268 if (cnt > max_tracer_type_len)
1269 cnt = max_tracer_type_len;
1270
1271 if (copy_from_user(&buf, ubuf, cnt))
1272 return -EFAULT;
1273
1274 buf[cnt] = 0;
1275
1276 /* strip ending whitespace. */
1277 for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
1278 buf[i] = 0;
1279
1280 mutex_lock(&trace_types_lock);
1281 for (t = trace_types; t; t = t->next) {
1282 if (strcmp(t->name, buf) == 0)
1283 break;
1284 }
1285 if (!t || t == current_trace)
1286 goto out;
1287
1288 if (current_trace && current_trace->reset)
1289 current_trace->reset(tr);
1290
1291 current_trace = t;
1292 if (t->init)
1293 t->init(tr);
1294
1295 out:
1296 mutex_unlock(&trace_types_lock);
1297
1298 filp->f_pos += cnt;
1299
1300 return cnt;
1301}
1302
1303static ssize_t
1304tracing_max_lat_read(struct file *filp, char __user *ubuf,
1305 size_t cnt, loff_t *ppos)
1306{
1307 unsigned long *ptr = filp->private_data;
1308 char buf[64];
1309 int r;
1310
1311 r = snprintf(buf, 64, "%ld\n",
1312 *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
1313 if (r > 64)
1314 r = 64;
1315 return simple_read_from_buffer(ubuf, cnt, ppos,
1316 buf, r);
1317}
1318
1319static ssize_t
1320tracing_max_lat_write(struct file *filp, const char __user *ubuf,
1321 size_t cnt, loff_t *ppos)
1322{
1323 long *ptr = filp->private_data;
1324 long val;
1325 char buf[64];
1326
1327 if (cnt > 63)
1328 cnt = 63;
1329
1330 if (copy_from_user(&buf, ubuf, cnt))
1331 return -EFAULT;
1332
1333 buf[cnt] = 0;
1334
1335 val = simple_strtoul(buf, NULL, 10);
1336
1337 *ptr = val * 1000;
1338
1339 return cnt;
1340}
1341
1342static struct file_operations tracing_max_lat_fops = {
1343 .open = tracing_open_generic,
1344 .read = tracing_max_lat_read,
1345 .write = tracing_max_lat_write,
1346};
1347
1348static struct file_operations tracing_ctrl_fops = {
1349 .open = tracing_open_generic,
1350 .read = tracing_ctrl_read,
1351 .write = tracing_ctrl_write,
1352};
1353
1354static struct file_operations set_tracer_fops = {
1355 .open = tracing_open_generic,
1356 .read = tracing_set_trace_read,
1357 .write = tracing_set_trace_write,
1358};
1359
1360#ifdef CONFIG_DYNAMIC_FTRACE
1361
1362static ssize_t
1363tracing_read_long(struct file *filp, char __user *ubuf,
1364 size_t cnt, loff_t *ppos)
1365{
1366 unsigned long *p = filp->private_data;
1367 char buf[64];
1368 int r;
1369
1370 r = sprintf(buf, "%ld\n", *p);
1371 return simple_read_from_buffer(ubuf, cnt, ppos,
1372 buf, r);
1373}
1374
1375static struct file_operations tracing_read_long_fops = {
1376 .open = tracing_open_generic,
1377 .read = tracing_read_long,
1378};
1379#endif
1380
1381static struct dentry *d_tracer;
1382
1383struct dentry *tracing_init_dentry(void)
1384{
1385 static int once;
1386
1387 if (d_tracer)
1388 return d_tracer;
1389
1390 d_tracer = debugfs_create_dir("tracing", NULL);
1391
1392 if (!d_tracer && !once) {
1393 once = 1;
1394 pr_warning("Could not create debugfs directory 'tracing'\n");
1395 return NULL;
1396 }
1397
1398 return d_tracer;
1399}
1400
1401static __init void tracer_init_debugfs(void)
1402{
1403 struct dentry *d_tracer;
1404 struct dentry *entry;
1405
1406 d_tracer = tracing_init_dentry();
1407
1408 entry = debugfs_create_file("tracing_enabled", 0644, d_tracer,
1409 &global_trace, &tracing_ctrl_fops);
1410 if (!entry)
1411 pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
1412
1413 entry = debugfs_create_file("iter_ctrl", 0644, d_tracer,
1414 NULL, &tracing_iter_fops);
1415 if (!entry)
1416 pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
1417
1418 entry = debugfs_create_file("latency_trace", 0444, d_tracer,
1419 &global_trace, &tracing_lt_fops);
1420 if (!entry)
1421 pr_warning("Could not create debugfs 'latency_trace' entry\n");
1422
1423 entry = debugfs_create_file("trace", 0444, d_tracer,
1424 &global_trace, &tracing_fops);
1425 if (!entry)
1426 pr_warning("Could not create debugfs 'trace' entry\n");
1427
1428 entry = debugfs_create_file("available_tracers", 0444, d_tracer,
1429 &global_trace, &show_traces_fops);
1430 if (!entry)
1431 pr_warning("Could not create debugfs 'trace' entry\n");
1432
1433 entry = debugfs_create_file("current_tracer", 0444, d_tracer,
1434 &global_trace, &set_tracer_fops);
1435 if (!entry)
1436 pr_warning("Could not create debugfs 'trace' entry\n");
1437
1438 entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer,
1439 &tracing_max_latency,
1440 &tracing_max_lat_fops);
1441 if (!entry)
1442 pr_warning("Could not create debugfs "
1443 "'tracing_max_latency' entry\n");
1444
1445 entry = debugfs_create_file("tracing_thresh", 0644, d_tracer,
1446 &tracing_thresh, &tracing_max_lat_fops);
1447 if (!entry)
1448 pr_warning("Could not create debugfs "
1449 "'tracing_threash' entry\n");
1450
1451#ifdef CONFIG_DYNAMIC_FTRACE
1452 entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
1453 &ftrace_update_tot_cnt,
1454 &tracing_read_long_fops);
1455 if (!entry)
1456 pr_warning("Could not create debugfs "
1457 "'dyn_ftrace_total_info' entry\n");
1458#endif
1459}
1460
1461/* dummy trace to disable tracing */
1462static struct tracer no_tracer __read_mostly =
1463{
1464 .name = "none",
1465};
1466
1467static inline notrace int page_order(const unsigned long size)
1468{
1469 const unsigned long nr_pages = DIV_ROUND_UP(size, PAGE_SIZE);
1470 return ilog2(roundup_pow_of_two(nr_pages));
1471}
1472
1473__init static int tracer_alloc_buffers(void)
1474{
1475 const int order = page_order(trace_nr_entries * TRACE_ENTRY_SIZE);
1476 const unsigned long size = (1UL << order) << PAGE_SHIFT;
1477 struct trace_entry *array;
1478 int i;
1479
1480 for_each_possible_cpu(i) {
1481 global_trace.data[i] = &per_cpu(global_trace_cpu, i);
1482 max_tr.data[i] = &per_cpu(max_data, i);
1483
1484 array = (struct trace_entry *)
1485 __get_free_pages(GFP_KERNEL, order);
1486 if (array == NULL) {
1487 printk(KERN_ERR "tracer: failed to allocate"
1488 " %ld bytes for trace buffer!\n", size);
1489 goto free_buffers;
1490 }
1491 global_trace.data[i]->trace = array;
1492
1493/* Only allocate if we are actually using the max trace */
1494#ifdef CONFIG_TRACER_MAX_TRACE
1495 array = (struct trace_entry *)
1496 __get_free_pages(GFP_KERNEL, order);
1497 if (array == NULL) {
1498 printk(KERN_ERR "wakeup tracer: failed to allocate"
1499 " %ld bytes for trace buffer!\n", size);
1500 goto free_buffers;
1501 }
1502 max_tr.data[i]->trace = array;
1503#endif
1504 }
1505
1506 /*
1507 * Since we allocate by orders of pages, we may be able to
1508 * round up a bit.
1509 */
1510 global_trace.entries = size / TRACE_ENTRY_SIZE;
1511 max_tr.entries = global_trace.entries;
1512
1513 pr_info("tracer: %ld bytes allocated for %ld",
1514 size, trace_nr_entries);
1515 pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE);
1516 pr_info(" actual entries %ld\n", global_trace.entries);
1517
1518 tracer_init_debugfs();
1519
1520 trace_init_cmdlines();
1521
1522 register_tracer(&no_tracer);
1523 current_trace = &no_tracer;
1524
1525 return 0;
1526
1527 free_buffers:
1528 for (i-- ; i >= 0; i--) {
1529 struct trace_array_cpu *data = global_trace.data[i];
1530
1531 if (data && data->trace) {
1532 free_pages((unsigned long)data->trace, order);
1533 data->trace = NULL;
1534 }
1535
1536#ifdef CONFIG_TRACER_MAX_TRACE
1537 data = max_tr.data[i];
1538 if (data && data->trace) {
1539 free_pages((unsigned long)data->trace, order);
1540 data->trace = NULL;
1541 }
1542#endif
1543 }
1544 return -ENOMEM;
1545}
1546
1547device_initcall(tracer_alloc_buffers);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
new file mode 100644
index 000000000000..3173a93561d4
--- /dev/null
+++ b/kernel/trace/trace.h
@@ -0,0 +1,184 @@
1#ifndef _LINUX_KERNEL_TRACE_H
2#define _LINUX_KERNEL_TRACE_H
3
4#include <linux/fs.h>
5#include <asm/atomic.h>
6#include <linux/sched.h>
7#include <linux/clocksource.h>
8
9/*
10 * Function trace entry - function address and parent function addres:
11 */
12struct ftrace_entry {
13 unsigned long ip;
14 unsigned long parent_ip;
15};
16
17/*
18 * Context switch trace entry - which task (and prio) we switched from/to:
19 */
20struct ctx_switch_entry {
21 unsigned int prev_pid;
22 unsigned char prev_prio;
23 unsigned char prev_state;
24 unsigned int next_pid;
25 unsigned char next_prio;
26};
27
28/*
29 * The trace entry - the most basic unit of tracing. This is what
30 * is printed in the end as a single line in the trace output, such as:
31 *
32 * bash-15816 [01] 235.197585: idle_cpu <- irq_enter
33 */
34struct trace_entry {
35 char type;
36 char cpu;
37 char flags;
38 char preempt_count;
39 int pid;
40 cycle_t t;
41 unsigned long idx;
42 union {
43 struct ftrace_entry fn;
44 struct ctx_switch_entry ctx;
45 };
46};
47
48#define TRACE_ENTRY_SIZE sizeof(struct trace_entry)
49
50/*
51 * The CPU trace array - it consists of thousands of trace entries
52 * plus some other descriptor data: (for example which task started
53 * the trace, etc.)
54 */
55struct trace_array_cpu {
56 void *trace;
57 unsigned long trace_idx;
58 atomic_t disabled;
59 atomic_t underrun;
60 unsigned long saved_latency;
61 unsigned long critical_start;
62 unsigned long critical_end;
63 unsigned long critical_sequence;
64 unsigned long nice;
65 unsigned long policy;
66 unsigned long rt_priority;
67 cycle_t preempt_timestamp;
68 pid_t pid;
69 uid_t uid;
70 char comm[TASK_COMM_LEN];
71};
72
73struct trace_iterator;
74
75/*
76 * The trace array - an array of per-CPU trace arrays. This is the
77 * highest level data structure that individual tracers deal with.
78 * They have on/off state as well:
79 */
80struct trace_array {
81 unsigned long entries;
82 long ctrl;
83 int cpu;
84 cycle_t time_start;
85 struct trace_array_cpu *data[NR_CPUS];
86};
87
88/*
89 * A specific tracer, represented by methods that operate on a trace array:
90 */
91struct tracer {
92 const char *name;
93 void (*init)(struct trace_array *tr);
94 void (*reset)(struct trace_array *tr);
95 void (*open)(struct trace_iterator *iter);
96 void (*close)(struct trace_iterator *iter);
97 void (*start)(struct trace_iterator *iter);
98 void (*stop)(struct trace_iterator *iter);
99 void (*ctrl_update)(struct trace_array *tr);
100 struct tracer *next;
101 int print_max;
102};
103
104/*
105 * Trace iterator - used by printout routines who present trace
106 * results to users and which routines might sleep, etc:
107 */
108struct trace_iterator {
109 struct trace_array *tr;
110 struct tracer *trace;
111 struct trace_entry *ent;
112 unsigned long iter_flags;
113 loff_t pos;
114 unsigned long next_idx[NR_CPUS];
115 int cpu;
116 int idx;
117};
118
119void notrace tracing_reset(struct trace_array_cpu *data);
120int tracing_open_generic(struct inode *inode, struct file *filp);
121struct dentry *tracing_init_dentry(void);
122void ftrace(struct trace_array *tr,
123 struct trace_array_cpu *data,
124 unsigned long ip,
125 unsigned long parent_ip,
126 unsigned long flags);
127void tracing_sched_switch_trace(struct trace_array *tr,
128 struct trace_array_cpu *data,
129 struct task_struct *prev,
130 struct task_struct *next,
131 unsigned long flags);
132void tracing_record_cmdline(struct task_struct *tsk);
133
134void tracing_start_function_trace(void);
135void tracing_stop_function_trace(void);
136int register_tracer(struct tracer *type);
137void unregister_tracer(struct tracer *type);
138
139extern unsigned long nsecs_to_usecs(unsigned long nsecs);
140
141extern unsigned long tracing_max_latency;
142extern unsigned long tracing_thresh;
143
144void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
145void update_max_tr_single(struct trace_array *tr,
146 struct task_struct *tsk, int cpu);
147
148static inline notrace cycle_t now(int cpu)
149{
150 return cpu_clock(cpu);
151}
152
153#ifdef CONFIG_SCHED_TRACER
154extern void notrace
155wakeup_sched_switch(struct task_struct *prev, struct task_struct *next);
156#else
157static inline void
158wakeup_sched_switch(struct task_struct *prev, struct task_struct *next)
159{
160}
161#endif
162
163#ifdef CONFIG_CONTEXT_SWITCH_TRACER
164typedef void
165(*tracer_switch_func_t)(void *private,
166 struct task_struct *prev,
167 struct task_struct *next);
168
169struct tracer_switch_ops {
170 tracer_switch_func_t func;
171 void *private;
172 struct tracer_switch_ops *next;
173};
174
175extern int register_tracer_switch(struct tracer_switch_ops *ops);
176extern int unregister_tracer_switch(struct tracer_switch_ops *ops);
177
178#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
179
180#ifdef CONFIG_DYNAMIC_FTRACE
181extern unsigned long ftrace_update_tot_cnt;
182#endif
183
184#endif /* _LINUX_KERNEL_TRACE_H */
generated by cgit v1.2.2 (git 2.25.0) at 2026-05-29 12:39:49 -0400