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14#include <linux/ring_buffer.h>
15#include <generated/utsrelease.h>
16#include <linux/stacktrace.h>
17#include <linux/writeback.h>
18#include <linux/kallsyms.h>
19#include <linux/seq_file.h>
20#include <linux/notifier.h>
21#include <linux/irqflags.h>
22#include <linux/debugfs.h>
23#include <linux/pagemap.h>
24#include <linux/hardirq.h>
25#include <linux/linkage.h>
26#include <linux/uaccess.h>
27#include <linux/kprobes.h>
28#include <linux/ftrace.h>
29#include <linux/module.h>
30#include <linux/percpu.h>
31#include <linux/splice.h>
32#include <linux/kdebug.h>
33#include <linux/string.h>
34#include <linux/rwsem.h>
35#include <linux/slab.h>
36#include <linux/ctype.h>
37#include <linux/init.h>
38#include <linux/poll.h>
39#include <linux/fs.h>
40
41#include "trace.h"
42#include "trace_output.h"
43
44#define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE)
45
46
47
48
49
50int ring_buffer_expanded;
51
52
53
54
55
56
57
58
59static bool __read_mostly tracing_selftest_running;
60
61
62
63
64bool __read_mostly tracing_selftest_disabled;
65
66
67static struct tracer_opt dummy_tracer_opt[] = {
68 { }
69};
70
71static struct tracer_flags dummy_tracer_flags = {
72 .val = 0,
73 .opts = dummy_tracer_opt
74};
75
76static int dummy_set_flag(u32 old_flags, u32 bit, int set)
77{
78 return 0;
79}
80
81
82
83
84
85
86
87static int tracing_disabled = 1;
88
89DEFINE_PER_CPU(int, ftrace_cpu_disabled);
90
91static inline void ftrace_disable_cpu(void)
92{
93 preempt_disable();
94 __this_cpu_inc(ftrace_cpu_disabled);
95}
96
97static inline void ftrace_enable_cpu(void)
98{
99 __this_cpu_dec(ftrace_cpu_disabled);
100 preempt_enable();
101}
102
103cpumask_var_t __read_mostly tracing_buffer_mask;
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121enum ftrace_dump_mode ftrace_dump_on_oops;
122
123static int tracing_set_tracer(const char *buf);
124
125#define MAX_TRACER_SIZE 100
126static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
127static char *default_bootup_tracer;
128
129static int __init set_cmdline_ftrace(char *str)
130{
131 strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
132 default_bootup_tracer = bootup_tracer_buf;
133
134 ring_buffer_expanded = 1;
135 return 1;
136}
137__setup("ftrace=", set_cmdline_ftrace);
138
139static int __init set_ftrace_dump_on_oops(char *str)
140{
141 if (*str++ != '=' || !*str) {
142 ftrace_dump_on_oops = DUMP_ALL;
143 return 1;
144 }
145
146 if (!strcmp("orig_cpu", str)) {
147 ftrace_dump_on_oops = DUMP_ORIG;
148 return 1;
149 }
150
151 return 0;
152}
153__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
154
155unsigned long long ns2usecs(cycle_t nsec)
156{
157 nsec += 500;
158 do_div(nsec, 1000);
159 return nsec;
160}
161
162
163
164
165
166
167
168
169
170
171
172
173
174static struct trace_array global_trace;
175
176static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
177
178int filter_current_check_discard(struct ring_buffer *buffer,
179 struct ftrace_event_call *call, void *rec,
180 struct ring_buffer_event *event)
181{
182 return filter_check_discard(call, rec, buffer, event);
183}
184EXPORT_SYMBOL_GPL(filter_current_check_discard);
185
186cycle_t ftrace_now(int cpu)
187{
188 u64 ts;
189
190
191 if (!global_trace.buffer)
192 return trace_clock_local();
193
194 ts = ring_buffer_time_stamp(global_trace.buffer, cpu);
195 ring_buffer_normalize_time_stamp(global_trace.buffer, cpu, &ts);
196
197 return ts;
198}
199
200
201
202
203
204
205
206
207
208
209
210static struct trace_array max_tr;
211
212static DEFINE_PER_CPU(struct trace_array_cpu, max_tr_data);
213
214
215static int tracer_enabled = 1;
216
217
218
219
220
221
222
223
224
225int tracing_is_enabled(void)
226{
227 return tracer_enabled;
228}
229
230
231
232
233
234
235
236
237
238
239
240#define TRACE_BUF_SIZE_DEFAULT 1441792UL
241
242static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
243
244
245static struct tracer *trace_types __read_mostly;
246
247
248static struct tracer *current_trace __read_mostly;
249
250
251
252
253static DEFINE_MUTEX(trace_types_lock);
254
255
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276
277#ifdef CONFIG_SMP
278static DECLARE_RWSEM(all_cpu_access_lock);
279static DEFINE_PER_CPU(struct mutex, cpu_access_lock);
280
281static inline void trace_access_lock(int cpu)
282{
283 if (cpu == TRACE_PIPE_ALL_CPU) {
284
285 down_write(&all_cpu_access_lock);
286 } else {
287
288
289
290 down_read(&all_cpu_access_lock);
291
292
293 mutex_lock(&per_cpu(cpu_access_lock, cpu));
294 }
295}
296
297static inline void trace_access_unlock(int cpu)
298{
299 if (cpu == TRACE_PIPE_ALL_CPU) {
300 up_write(&all_cpu_access_lock);
301 } else {
302 mutex_unlock(&per_cpu(cpu_access_lock, cpu));
303 up_read(&all_cpu_access_lock);
304 }
305}
306
307static inline void trace_access_lock_init(void)
308{
309 int cpu;
310
311 for_each_possible_cpu(cpu)
312 mutex_init(&per_cpu(cpu_access_lock, cpu));
313}
314
315#else
316
317static DEFINE_MUTEX(access_lock);
318
319static inline void trace_access_lock(int cpu)
320{
321 (void)cpu;
322 mutex_lock(&access_lock);
323}
324
325static inline void trace_access_unlock(int cpu)
326{
327 (void)cpu;
328 mutex_unlock(&access_lock);
329}
330
331static inline void trace_access_lock_init(void)
332{
333}
334
335#endif
336
337
338static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
339
340
341unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
342 TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
343 TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD;
344
345static int trace_stop_count;
346static DEFINE_SPINLOCK(tracing_start_lock);
347
348
349
350
351
352
353
354void trace_wake_up(void)
355{
356 int cpu;
357
358 if (trace_flags & TRACE_ITER_BLOCK)
359 return;
360
361
362
363
364 cpu = get_cpu();
365 if (!runqueue_is_locked(cpu))
366 wake_up(&trace_wait);
367 put_cpu();
368}
369
370static int __init set_buf_size(char *str)
371{
372 unsigned long buf_size;
373
374 if (!str)
375 return 0;
376 buf_size = memparse(str, &str);
377
378 if (buf_size == 0)
379 return 0;
380 trace_buf_size = buf_size;
381 return 1;
382}
383__setup("trace_buf_size=", set_buf_size);
384
385static int __init set_tracing_thresh(char *str)
386{
387 unsigned long threshhold;
388 int ret;
389
390 if (!str)
391 return 0;
392 ret = strict_strtoul(str, 0, &threshhold);
393 if (ret < 0)
394 return 0;
395 tracing_thresh = threshhold * 1000;
396 return 1;
397}
398__setup("tracing_thresh=", set_tracing_thresh);
399
400unsigned long nsecs_to_usecs(unsigned long nsecs)
401{
402 return nsecs / 1000;
403}
404
405
406static const char *trace_options[] = {
407 "print-parent",
408 "sym-offset",
409 "sym-addr",
410 "verbose",
411 "raw",
412 "hex",
413 "bin",
414 "block",
415 "stacktrace",
416 "trace_printk",
417 "ftrace_preempt",
418 "branch",
419 "annotate",
420 "userstacktrace",
421 "sym-userobj",
422 "printk-msg-only",
423 "context-info",
424 "latency-format",
425 "sleep-time",
426 "graph-time",
427 "record-cmd",
428 NULL
429};
430
431static struct {
432 u64 (*func)(void);
433 const char *name;
434} trace_clocks[] = {
435 { trace_clock_local, "local" },
436 { trace_clock_global, "global" },
437};
438
439int trace_clock_id;
440
441
442
443
444int trace_parser_get_init(struct trace_parser *parser, int size)
445{
446 memset(parser, 0, sizeof(*parser));
447
448 parser->buffer = kmalloc(size, GFP_KERNEL);
449 if (!parser->buffer)
450 return 1;
451
452 parser->size = size;
453 return 0;
454}
455
456
457
458
459void trace_parser_put(struct trace_parser *parser)
460{
461 kfree(parser->buffer);
462}
463
464
465
466
467
468
469
470
471
472
473
474
475int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
476 size_t cnt, loff_t *ppos)
477{
478 char ch;
479 size_t read = 0;
480 ssize_t ret;
481
482 if (!*ppos)
483 trace_parser_clear(parser);
484
485 ret = get_user(ch, ubuf++);
486 if (ret)
487 goto out;
488
489 read++;
490 cnt--;
491
492
493
494
495
496 if (!parser->cont) {
497
498 while (cnt && isspace(ch)) {
499 ret = get_user(ch, ubuf++);
500 if (ret)
501 goto out;
502 read++;
503 cnt--;
504 }
505
506
507 if (isspace(ch)) {
508 *ppos += read;
509 ret = read;
510 goto out;
511 }
512
513 parser->idx = 0;
514 }
515
516
517 while (cnt && !isspace(ch)) {
518 if (parser->idx < parser->size - 1)
519 parser->buffer[parser->idx++] = ch;
520 else {
521 ret = -EINVAL;
522 goto out;
523 }
524 ret = get_user(ch, ubuf++);
525 if (ret)
526 goto out;
527 read++;
528 cnt--;
529 }
530
531
532 if (isspace(ch)) {
533 parser->buffer[parser->idx] = 0;
534 parser->cont = false;
535 } else {
536 parser->cont = true;
537 parser->buffer[parser->idx++] = ch;
538 }
539
540 *ppos += read;
541 ret = read;
542
543out:
544 return ret;
545}
546
547ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
548{
549 int len;
550 int ret;
551
552 if (!cnt)
553 return 0;
554
555 if (s->len <= s->readpos)
556 return -EBUSY;
557
558 len = s->len - s->readpos;
559 if (cnt > len)
560 cnt = len;
561 ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
562 if (ret == cnt)
563 return -EFAULT;
564
565 cnt -= ret;
566
567 s->readpos += cnt;
568 return cnt;
569}
570
571static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
572{
573 int len;
574 void *ret;
575
576 if (s->len <= s->readpos)
577 return -EBUSY;
578
579 len = s->len - s->readpos;
580 if (cnt > len)
581 cnt = len;
582 ret = memcpy(buf, s->buffer + s->readpos, cnt);
583 if (!ret)
584 return -EFAULT;
585
586 s->readpos += cnt;
587 return cnt;
588}
589
590
591
592
593
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595
596
597
598
599
600
601
602
603static arch_spinlock_t ftrace_max_lock =
604 (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
605
606unsigned long __read_mostly tracing_thresh;
607
608#ifdef CONFIG_TRACER_MAX_TRACE
609unsigned long __read_mostly tracing_max_latency;
610
611
612
613
614
615
616static void
617__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
618{
619 struct trace_array_cpu *data = tr->data[cpu];
620 struct trace_array_cpu *max_data;
621
622 max_tr.cpu = cpu;
623 max_tr.time_start = data->preempt_timestamp;
624
625 max_data = max_tr.data[cpu];
626 max_data->saved_latency = tracing_max_latency;
627 max_data->critical_start = data->critical_start;
628 max_data->critical_end = data->critical_end;
629
630 memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
631 max_data->pid = tsk->pid;
632 max_data->uid = task_uid(tsk);
633 max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
634 max_data->policy = tsk->policy;
635 max_data->rt_priority = tsk->rt_priority;
636
637
638 tracing_record_cmdline(tsk);
639}
640
641
642
643
644
645
646
647
648
649
650void
651update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
652{
653 struct ring_buffer *buf = tr->buffer;
654
655 if (trace_stop_count)
656 return;
657
658 WARN_ON_ONCE(!irqs_disabled());
659 if (!current_trace->use_max_tr) {
660 WARN_ON_ONCE(1);
661 return;
662 }
663 arch_spin_lock(&ftrace_max_lock);
664
665 tr->buffer = max_tr.buffer;
666 max_tr.buffer = buf;
667
668 __update_max_tr(tr, tsk, cpu);
669 arch_spin_unlock(&ftrace_max_lock);
670}
671
672
673
674
675
676
677
678
679
680void
681update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
682{
683 int ret;
684
685 if (trace_stop_count)
686 return;
687
688 WARN_ON_ONCE(!irqs_disabled());
689 if (!current_trace->use_max_tr) {
690 WARN_ON_ONCE(1);
691 return;
692 }
693
694 arch_spin_lock(&ftrace_max_lock);
695
696 ftrace_disable_cpu();
697
698 ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
699
700 if (ret == -EBUSY) {
701
702
703
704
705
706
707 trace_array_printk(&max_tr, _THIS_IP_,
708 "Failed to swap buffers due to commit in progress\n");
709 }
710
711 ftrace_enable_cpu();
712
713 WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY);
714
715 __update_max_tr(tr, tsk, cpu);
716 arch_spin_unlock(&ftrace_max_lock);
717}
718#endif
719
720
721
722
723
724
725
726int register_tracer(struct tracer *type)
727__releases(kernel_lock)
728__acquires(kernel_lock)
729{
730 struct tracer *t;
731 int ret = 0;
732
733 if (!type->name) {
734 pr_info("Tracer must have a name\n");
735 return -1;
736 }
737
738 if (strlen(type->name) >= MAX_TRACER_SIZE) {
739 pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);
740 return -1;
741 }
742
743 mutex_lock(&trace_types_lock);
744
745 tracing_selftest_running = true;
746
747 for (t = trace_types; t; t = t->next) {
748 if (strcmp(type->name, t->name) == 0) {
749
750 pr_info("Tracer %s already registered\n",
751 type->name);
752 ret = -1;
753 goto out;
754 }
755 }
756
757 if (!type->set_flag)
758 type->set_flag = &dummy_set_flag;
759 if (!type->flags)
760 type->flags = &dummy_tracer_flags;
761 else
762 if (!type->flags->opts)
763 type->flags->opts = dummy_tracer_opt;
764 if (!type->wait_pipe)
765 type->wait_pipe = default_wait_pipe;
766
767
768#ifdef CONFIG_FTRACE_STARTUP_TEST
769 if (type->selftest && !tracing_selftest_disabled) {
770 struct tracer *saved_tracer = current_trace;
771 struct trace_array *tr = &global_trace;
772
773
774
775
776
777
778
779
780 tracing_reset_online_cpus(tr);
781
782 current_trace = type;
783
784 pr_info("Testing tracer %s: ", type->name);
785 ret = type->selftest(type, tr);
786
787 current_trace = saved_tracer;
788 if (ret) {
789 printk(KERN_CONT "FAILED!\n");
790 goto out;
791 }
792
793 tracing_reset_online_cpus(tr);
794
795 printk(KERN_CONT "PASSED\n");
796 }
797#endif
798
799 type->next = trace_types;
800 trace_types = type;
801
802 out:
803 tracing_selftest_running = false;
804 mutex_unlock(&trace_types_lock);
805
806 if (ret || !default_bootup_tracer)
807 goto out_unlock;
808
809 if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
810 goto out_unlock;
811
812 printk(KERN_INFO "Starting tracer '%s'\n", type->name);
813
814 tracing_set_tracer(type->name);
815 default_bootup_tracer = NULL;
816
817 tracing_selftest_disabled = 1;
818#ifdef CONFIG_FTRACE_STARTUP_TEST
819 printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n",
820 type->name);
821#endif
822
823 out_unlock:
824 return ret;
825}
826
827void unregister_tracer(struct tracer *type)
828{
829 struct tracer **t;
830
831 mutex_lock(&trace_types_lock);
832 for (t = &trace_types; *t; t = &(*t)->next) {
833 if (*t == type)
834 goto found;
835 }
836 pr_info("Tracer %s not registered\n", type->name);
837 goto out;
838
839 found:
840 *t = (*t)->next;
841
842 if (type == current_trace && tracer_enabled) {
843 tracer_enabled = 0;
844 tracing_stop();
845 if (current_trace->stop)
846 current_trace->stop(&global_trace);
847 current_trace = &nop_trace;
848 }
849out:
850 mutex_unlock(&trace_types_lock);
851}
852
853static void __tracing_reset(struct ring_buffer *buffer, int cpu)
854{
855 ftrace_disable_cpu();
856 ring_buffer_reset_cpu(buffer, cpu);
857 ftrace_enable_cpu();
858}
859
860void tracing_reset(struct trace_array *tr, int cpu)
861{
862 struct ring_buffer *buffer = tr->buffer;
863
864 ring_buffer_record_disable(buffer);
865
866
867 synchronize_sched();
868 __tracing_reset(buffer, cpu);
869
870 ring_buffer_record_enable(buffer);
871}
872
873void tracing_reset_online_cpus(struct trace_array *tr)
874{
875 struct ring_buffer *buffer = tr->buffer;
876 int cpu;
877
878 ring_buffer_record_disable(buffer);
879
880
881 synchronize_sched();
882
883 tr->time_start = ftrace_now(tr->cpu);
884
885 for_each_online_cpu(cpu)
886 __tracing_reset(buffer, cpu);
887
888 ring_buffer_record_enable(buffer);
889}
890
891void tracing_reset_current(int cpu)
892{
893 tracing_reset(&global_trace, cpu);
894}
895
896void tracing_reset_current_online_cpus(void)
897{
898 tracing_reset_online_cpus(&global_trace);
899}
900
901#define SAVED_CMDLINES 128
902#define NO_CMDLINE_MAP UINT_MAX
903static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
904static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
905static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
906static int cmdline_idx;
907static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
908
909
910static atomic_t trace_record_cmdline_disabled __read_mostly;
911
912static void trace_init_cmdlines(void)
913{
914 memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline));
915 memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid));
916 cmdline_idx = 0;
917}
918
919int is_tracing_stopped(void)
920{
921 return trace_stop_count;
922}
923
924
925
926
927
928
929
930
931
932void ftrace_off_permanent(void)
933{
934 tracing_disabled = 1;
935 ftrace_stop();
936 tracing_off_permanent();
937}
938
939
940
941
942
943
944
945void tracing_start(void)
946{
947 struct ring_buffer *buffer;
948 unsigned long flags;
949
950 if (tracing_disabled)
951 return;
952
953 spin_lock_irqsave(&tracing_start_lock, flags);
954 if (--trace_stop_count) {
955 if (trace_stop_count < 0) {
956
957 WARN_ON_ONCE(1);
958 trace_stop_count = 0;
959 }
960 goto out;
961 }
962
963
964 arch_spin_lock(&ftrace_max_lock);
965
966 buffer = global_trace.buffer;
967 if (buffer)
968 ring_buffer_record_enable(buffer);
969
970 buffer = max_tr.buffer;
971 if (buffer)
972 ring_buffer_record_enable(buffer);
973
974 arch_spin_unlock(&ftrace_max_lock);
975
976 ftrace_start();
977 out:
978 spin_unlock_irqrestore(&tracing_start_lock, flags);
979}
980
981
982
983
984
985
986
987void tracing_stop(void)
988{
989 struct ring_buffer *buffer;
990 unsigned long flags;
991
992 ftrace_stop();
993 spin_lock_irqsave(&tracing_start_lock, flags);
994 if (trace_stop_count++)
995 goto out;
996
997
998 arch_spin_lock(&ftrace_max_lock);
999
1000 buffer = global_trace.buffer;
1001 if (buffer)
1002 ring_buffer_record_disable(buffer);
1003
1004 buffer = max_tr.buffer;
1005 if (buffer)
1006 ring_buffer_record_disable(buffer);
1007
1008 arch_spin_unlock(&ftrace_max_lock);
1009
1010 out:
1011 spin_unlock_irqrestore(&tracing_start_lock, flags);
1012}
1013
1014void trace_stop_cmdline_recording(void);
1015
1016static void trace_save_cmdline(struct task_struct *tsk)
1017{
1018 unsigned pid, idx;
1019
1020 if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
1021 return;
1022
1023
1024
1025
1026
1027
1028
1029 if (!arch_spin_trylock(&trace_cmdline_lock))
1030 return;
1031
1032 idx = map_pid_to_cmdline[tsk->pid];
1033 if (idx == NO_CMDLINE_MAP) {
1034 idx = (cmdline_idx + 1) % SAVED_CMDLINES;
1035
1036
1037
1038
1039
1040
1041
1042 pid = map_cmdline_to_pid[idx];
1043 if (pid != NO_CMDLINE_MAP)
1044 map_pid_to_cmdline[pid] = NO_CMDLINE_MAP;
1045
1046 map_cmdline_to_pid[idx] = tsk->pid;
1047 map_pid_to_cmdline[tsk->pid] = idx;
1048
1049 cmdline_idx = idx;
1050 }
1051
1052 memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
1053
1054 arch_spin_unlock(&trace_cmdline_lock);
1055}
1056
1057void trace_find_cmdline(int pid, char comm[])
1058{
1059 unsigned map;
1060
1061 if (!pid) {
1062 strcpy(comm, "<idle>");
1063 return;
1064 }
1065
1066 if (WARN_ON_ONCE(pid < 0)) {
1067 strcpy(comm, "<XXX>");
1068 return;
1069 }
1070
1071 if (pid > PID_MAX_DEFAULT) {
1072 strcpy(comm, "<...>");
1073 return;
1074 }
1075
1076 preempt_disable();
1077 arch_spin_lock(&trace_cmdline_lock);
1078 map = map_pid_to_cmdline[pid];
1079 if (map != NO_CMDLINE_MAP)
1080 strcpy(comm, saved_cmdlines[map]);
1081 else
1082 strcpy(comm, "<...>");
1083
1084 arch_spin_unlock(&trace_cmdline_lock);
1085 preempt_enable();
1086}
1087
1088void tracing_record_cmdline(struct task_struct *tsk)
1089{
1090 if (atomic_read(&trace_record_cmdline_disabled) || !tracer_enabled ||
1091 !tracing_is_on())
1092 return;
1093
1094 trace_save_cmdline(tsk);
1095}
1096
1097void
1098tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
1099 int pc)
1100{
1101 struct task_struct *tsk = current;
1102
1103 entry->preempt_count = pc & 0xff;
1104 entry->pid = (tsk) ? tsk->pid : 0;
1105 entry->lock_depth = (tsk) ? tsk->lock_depth : 0;
1106 entry->flags =
1107#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
1108 (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
1109#else
1110 TRACE_FLAG_IRQS_NOSUPPORT |
1111#endif
1112 ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
1113 ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
1114 (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
1115}
1116EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
1117
1118struct ring_buffer_event *
1119trace_buffer_lock_reserve(struct ring_buffer *buffer,
1120 int type,
1121 unsigned long len,
1122 unsigned long flags, int pc)
1123{
1124 struct ring_buffer_event *event;
1125
1126 event = ring_buffer_lock_reserve(buffer, len);
1127 if (event != NULL) {
1128 struct trace_entry *ent = ring_buffer_event_data(event);
1129
1130 tracing_generic_entry_update(ent, flags, pc);
1131 ent->type = type;
1132 }
1133
1134 return event;
1135}
1136
1137static inline void
1138__trace_buffer_unlock_commit(struct ring_buffer *buffer,
1139 struct ring_buffer_event *event,
1140 unsigned long flags, int pc,
1141 int wake)
1142{
1143 ring_buffer_unlock_commit(buffer, event);
1144
1145 ftrace_trace_stack(buffer, flags, 6, pc);
1146 ftrace_trace_userstack(buffer, flags, pc);
1147
1148 if (wake)
1149 trace_wake_up();
1150}
1151
1152void trace_buffer_unlock_commit(struct ring_buffer *buffer,
1153 struct ring_buffer_event *event,
1154 unsigned long flags, int pc)
1155{
1156 __trace_buffer_unlock_commit(buffer, event, flags, pc, 1);
1157}
1158
1159struct ring_buffer_event *
1160trace_current_buffer_lock_reserve(struct ring_buffer **current_rb,
1161 int type, unsigned long len,
1162 unsigned long flags, int pc)
1163{
1164 *current_rb = global_trace.buffer;
1165 return trace_buffer_lock_reserve(*current_rb,
1166 type, len, flags, pc);
1167}
1168EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve);
1169
1170void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
1171 struct ring_buffer_event *event,
1172 unsigned long flags, int pc)
1173{
1174 __trace_buffer_unlock_commit(buffer, event, flags, pc, 1);
1175}
1176EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit);
1177
1178void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
1179 struct ring_buffer_event *event,
1180 unsigned long flags, int pc)
1181{
1182 __trace_buffer_unlock_commit(buffer, event, flags, pc, 0);
1183}
1184EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit);
1185
1186void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
1187 struct ring_buffer_event *event)
1188{
1189 ring_buffer_discard_commit(buffer, event);
1190}
1191EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit);
1192
1193void
1194trace_function(struct trace_array *tr,
1195 unsigned long ip, unsigned long parent_ip, unsigned long flags,
1196 int pc)
1197{
1198 struct ftrace_event_call *call = &event_function;
1199 struct ring_buffer *buffer = tr->buffer;
1200 struct ring_buffer_event *event;
1201 struct ftrace_entry *entry;
1202
1203
1204 if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
1205 return;
1206
1207 event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
1208 flags, pc);
1209 if (!event)
1210 return;
1211 entry = ring_buffer_event_data(event);
1212 entry->ip = ip;
1213 entry->parent_ip = parent_ip;
1214
1215 if (!filter_check_discard(call, entry, buffer, event))
1216 ring_buffer_unlock_commit(buffer, event);
1217}
1218
1219void
1220ftrace(struct trace_array *tr, struct trace_array_cpu *data,
1221 unsigned long ip, unsigned long parent_ip, unsigned long flags,
1222 int pc)
1223{
1224 if (likely(!atomic_read(&data->disabled)))
1225 trace_function(tr, ip, parent_ip, flags, pc);
1226}
1227
1228#ifdef CONFIG_STACKTRACE
1229static void __ftrace_trace_stack(struct ring_buffer *buffer,
1230 unsigned long flags,
1231 int skip, int pc)
1232{
1233 struct ftrace_event_call *call = &event_kernel_stack;
1234 struct ring_buffer_event *event;
1235 struct stack_entry *entry;
1236 struct stack_trace trace;
1237
1238 event = trace_buffer_lock_reserve(buffer, TRACE_STACK,
1239 sizeof(*entry), flags, pc);
1240 if (!event)
1241 return;
1242 entry = ring_buffer_event_data(event);
1243 memset(&entry->caller, 0, sizeof(entry->caller));
1244
1245 trace.nr_entries = 0;
1246 trace.max_entries = FTRACE_STACK_ENTRIES;
1247 trace.skip = skip;
1248 trace.entries = entry->caller;
1249
1250 save_stack_trace(&trace);
1251 if (!filter_check_discard(call, entry, buffer, event))
1252 ring_buffer_unlock_commit(buffer, event);
1253}
1254
1255void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
1256 int skip, int pc)
1257{
1258 if (!(trace_flags & TRACE_ITER_STACKTRACE))
1259 return;
1260
1261 __ftrace_trace_stack(buffer, flags, skip, pc);
1262}
1263
1264void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
1265 int pc)
1266{
1267 __ftrace_trace_stack(tr->buffer, flags, skip, pc);
1268}
1269
1270
1271
1272
1273void trace_dump_stack(void)
1274{
1275 unsigned long flags;
1276
1277 if (tracing_disabled || tracing_selftest_running)
1278 return;
1279
1280 local_save_flags(flags);
1281
1282
1283 __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count());
1284}
1285
1286static DEFINE_PER_CPU(int, user_stack_count);
1287
1288void
1289ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
1290{
1291 struct ftrace_event_call *call = &event_user_stack;
1292 struct ring_buffer_event *event;
1293 struct userstack_entry *entry;
1294 struct stack_trace trace;
1295
1296 if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
1297 return;
1298
1299
1300
1301
1302
1303 if (unlikely(in_nmi()))
1304 return;
1305
1306
1307
1308
1309
1310 preempt_disable();
1311 if (__this_cpu_read(user_stack_count))
1312 goto out;
1313
1314 __this_cpu_inc(user_stack_count);
1315
1316 event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
1317 sizeof(*entry), flags, pc);
1318 if (!event)
1319 goto out_drop_count;
1320 entry = ring_buffer_event_data(event);
1321
1322 entry->tgid = current->tgid;
1323 memset(&entry->caller, 0, sizeof(entry->caller));
1324
1325 trace.nr_entries = 0;
1326 trace.max_entries = FTRACE_STACK_ENTRIES;
1327 trace.skip = 0;
1328 trace.entries = entry->caller;
1329
1330 save_stack_trace_user(&trace);
1331 if (!filter_check_discard(call, entry, buffer, event))
1332 ring_buffer_unlock_commit(buffer, event);
1333
1334 out_drop_count:
1335 __this_cpu_dec(user_stack_count);
1336 out:
1337 preempt_enable();
1338}
1339
1340#ifdef UNUSED
1341static void __trace_userstack(struct trace_array *tr, unsigned long flags)
1342{
1343 ftrace_trace_userstack(tr, flags, preempt_count());
1344}
1345#endif
1346
1347#endif
1348
1349
1350
1351
1352
1353int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
1354{
1355 static arch_spinlock_t trace_buf_lock =
1356 (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
1357 static u32 trace_buf[TRACE_BUF_SIZE];
1358
1359 struct ftrace_event_call *call = &event_bprint;
1360 struct ring_buffer_event *event;
1361 struct ring_buffer *buffer;
1362 struct trace_array *tr = &global_trace;
1363 struct trace_array_cpu *data;
1364 struct bprint_entry *entry;
1365 unsigned long flags;
1366 int disable;
1367 int cpu, len = 0, size, pc;
1368
1369 if (unlikely(tracing_selftest_running || tracing_disabled))
1370 return 0;
1371
1372
1373 pause_graph_tracing();
1374
1375 pc = preempt_count();
1376 preempt_disable_notrace();
1377 cpu = raw_smp_processor_id();
1378 data = tr->data[cpu];
1379
1380 disable = atomic_inc_return(&data->disabled);
1381 if (unlikely(disable != 1))
1382 goto out;
1383
1384
1385 local_irq_save(flags);
1386 arch_spin_lock(&trace_buf_lock);
1387 len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args);
1388
1389 if (len > TRACE_BUF_SIZE || len < 0)
1390 goto out_unlock;
1391
1392 size = sizeof(*entry) + sizeof(u32) * len;
1393 buffer = tr->buffer;
1394 event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
1395 flags, pc);
1396 if (!event)
1397 goto out_unlock;
1398 entry = ring_buffer_event_data(event);
1399 entry->ip = ip;
1400 entry->fmt = fmt;
1401
1402 memcpy(entry->buf, trace_buf, sizeof(u32) * len);
1403 if (!filter_check_discard(call, entry, buffer, event)) {
1404 ring_buffer_unlock_commit(buffer, event);
1405 ftrace_trace_stack(buffer, flags, 6, pc);
1406 }
1407
1408out_unlock:
1409 arch_spin_unlock(&trace_buf_lock);
1410 local_irq_restore(flags);
1411
1412out:
1413 atomic_dec_return(&data->disabled);
1414 preempt_enable_notrace();
1415 unpause_graph_tracing();
1416
1417 return len;
1418}
1419EXPORT_SYMBOL_GPL(trace_vbprintk);
1420
1421int trace_array_printk(struct trace_array *tr,
1422 unsigned long ip, const char *fmt, ...)
1423{
1424 int ret;
1425 va_list ap;
1426
1427 if (!(trace_flags & TRACE_ITER_PRINTK))
1428 return 0;
1429
1430 va_start(ap, fmt);
1431 ret = trace_array_vprintk(tr, ip, fmt, ap);
1432 va_end(ap);
1433 return ret;
1434}
1435
1436int trace_array_vprintk(struct trace_array *tr,
1437 unsigned long ip, const char *fmt, va_list args)
1438{
1439 static arch_spinlock_t trace_buf_lock = __ARCH_SPIN_LOCK_UNLOCKED;
1440 static char trace_buf[TRACE_BUF_SIZE];
1441
1442 struct ftrace_event_call *call = &event_print;
1443 struct ring_buffer_event *event;
1444 struct ring_buffer *buffer;
1445 struct trace_array_cpu *data;
1446 int cpu, len = 0, size, pc;
1447 struct print_entry *entry;
1448 unsigned long irq_flags;
1449 int disable;
1450
1451 if (tracing_disabled || tracing_selftest_running)
1452 return 0;
1453
1454 pc = preempt_count();
1455 preempt_disable_notrace();
1456 cpu = raw_smp_processor_id();
1457 data = tr->data[cpu];
1458
1459 disable = atomic_inc_return(&data->disabled);
1460 if (unlikely(disable != 1))
1461 goto out;
1462
1463 pause_graph_tracing();
1464 raw_local_irq_save(irq_flags);
1465 arch_spin_lock(&trace_buf_lock);
1466 len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
1467
1468 size = sizeof(*entry) + len + 1;
1469 buffer = tr->buffer;
1470 event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
1471 irq_flags, pc);
1472 if (!event)
1473 goto out_unlock;
1474 entry = ring_buffer_event_data(event);
1475 entry->ip = ip;
1476
1477 memcpy(&entry->buf, trace_buf, len);
1478 entry->buf[len] = '\0';
1479 if (!filter_check_discard(call, entry, buffer, event)) {
1480 ring_buffer_unlock_commit(buffer, event);
1481 ftrace_trace_stack(buffer, irq_flags, 6, pc);
1482 }
1483
1484 out_unlock:
1485 arch_spin_unlock(&trace_buf_lock);
1486 raw_local_irq_restore(irq_flags);
1487 unpause_graph_tracing();
1488 out:
1489 atomic_dec_return(&data->disabled);
1490 preempt_enable_notrace();
1491
1492 return len;
1493}
1494
1495int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
1496{
1497 return trace_array_vprintk(&global_trace, ip, fmt, args);
1498}
1499EXPORT_SYMBOL_GPL(trace_vprintk);
1500
1501static void trace_iterator_increment(struct trace_iterator *iter)
1502{
1503
1504 ftrace_disable_cpu();
1505
1506 iter->idx++;
1507 if (iter->buffer_iter[iter->cpu])
1508 ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
1509
1510 ftrace_enable_cpu();
1511}
1512
1513static struct trace_entry *
1514peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
1515 unsigned long *lost_events)
1516{
1517 struct ring_buffer_event *event;
1518 struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
1519
1520
1521 ftrace_disable_cpu();
1522
1523 if (buf_iter)
1524 event = ring_buffer_iter_peek(buf_iter, ts);
1525 else
1526 event = ring_buffer_peek(iter->tr->buffer, cpu, ts,
1527 lost_events);
1528
1529 ftrace_enable_cpu();
1530
1531 return event ? ring_buffer_event_data(event) : NULL;
1532}
1533
1534static struct trace_entry *
1535__find_next_entry(struct trace_iterator *iter, int *ent_cpu,
1536 unsigned long *missing_events, u64 *ent_ts)
1537{
1538 struct ring_buffer *buffer = iter->tr->buffer;
1539 struct trace_entry *ent, *next = NULL;
1540 unsigned long lost_events = 0, next_lost = 0;
1541 int cpu_file = iter->cpu_file;
1542 u64 next_ts = 0, ts;
1543 int next_cpu = -1;
1544 int cpu;
1545
1546
1547
1548
1549
1550 if (cpu_file > TRACE_PIPE_ALL_CPU) {
1551 if (ring_buffer_empty_cpu(buffer, cpu_file))
1552 return NULL;
1553 ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events);
1554 if (ent_cpu)
1555 *ent_cpu = cpu_file;
1556
1557 return ent;
1558 }
1559
1560 for_each_tracing_cpu(cpu) {
1561
1562 if (ring_buffer_empty_cpu(buffer, cpu))
1563 continue;
1564
1565 ent = peek_next_entry(iter, cpu, &ts, &lost_events);
1566
1567
1568
1569
1570 if (ent && (!next || ts < next_ts)) {
1571 next = ent;
1572 next_cpu = cpu;
1573 next_ts = ts;
1574 next_lost = lost_events;
1575 }
1576 }
1577
1578 if (ent_cpu)
1579 *ent_cpu = next_cpu;
1580
1581 if (ent_ts)
1582 *ent_ts = next_ts;
1583
1584 if (missing_events)
1585 *missing_events = next_lost;
1586
1587 return next;
1588}
1589
1590
1591struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
1592 int *ent_cpu, u64 *ent_ts)
1593{
1594 return __find_next_entry(iter, ent_cpu, NULL, ent_ts);
1595}
1596
1597
1598void *trace_find_next_entry_inc(struct trace_iterator *iter)
1599{
1600 iter->ent = __find_next_entry(iter, &iter->cpu,
1601 &iter->lost_events, &iter->ts);
1602
1603 if (iter->ent)
1604 trace_iterator_increment(iter);
1605
1606 return iter->ent ? iter : NULL;
1607}
1608
1609static void trace_consume(struct trace_iterator *iter)
1610{
1611
1612 ftrace_disable_cpu();
1613 ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts,
1614 &iter->lost_events);
1615 ftrace_enable_cpu();
1616}
1617
1618static void *s_next(struct seq_file *m, void *v, loff_t *pos)
1619{
1620 struct trace_iterator *iter = m->private;
1621 int i = (int)*pos;
1622 void *ent;
1623
1624 WARN_ON_ONCE(iter->leftover);
1625
1626 (*pos)++;
1627
1628
1629 if (iter->idx > i)
1630 return NULL;
1631
1632 if (iter->idx < 0)
1633 ent = trace_find_next_entry_inc(iter);
1634 else
1635 ent = iter;
1636
1637 while (ent && iter->idx < i)
1638 ent = trace_find_next_entry_inc(iter);
1639
1640 iter->pos = *pos;
1641
1642 return ent;
1643}
1644
1645void tracing_iter_reset(struct trace_iterator *iter, int cpu)
1646{
1647 struct trace_array *tr = iter->tr;
1648 struct ring_buffer_event *event;
1649 struct ring_buffer_iter *buf_iter;
1650 unsigned long entries = 0;
1651 u64 ts;
1652
1653 tr->data[cpu]->skipped_entries = 0;
1654
1655 if (!iter->buffer_iter[cpu])
1656 return;
1657
1658 buf_iter = iter->buffer_iter[cpu];
1659 ring_buffer_iter_reset(buf_iter);
1660
1661
1662
1663
1664
1665
1666 while ((event = ring_buffer_iter_peek(buf_iter, &ts))) {
1667 if (ts >= iter->tr->time_start)
1668 break;
1669 entries++;
1670 ring_buffer_read(buf_iter, NULL);
1671 }
1672
1673 tr->data[cpu]->skipped_entries = entries;
1674}
1675
1676
1677
1678
1679
1680static void *s_start(struct seq_file *m, loff_t *pos)
1681{
1682 struct trace_iterator *iter = m->private;
1683 static struct tracer *old_tracer;
1684 int cpu_file = iter->cpu_file;
1685 void *p = NULL;
1686 loff_t l = 0;
1687 int cpu;
1688
1689
1690 mutex_lock(&trace_types_lock);
1691 if (unlikely(old_tracer != current_trace && current_trace)) {
1692 old_tracer = current_trace;
1693 *iter->trace = *current_trace;
1694 }
1695 mutex_unlock(&trace_types_lock);
1696
1697 atomic_inc(&trace_record_cmdline_disabled);
1698
1699 if (*pos != iter->pos) {
1700 iter->ent = NULL;
1701 iter->cpu = 0;
1702 iter->idx = -1;
1703
1704 ftrace_disable_cpu();
1705
1706 if (cpu_file == TRACE_PIPE_ALL_CPU) {
1707 for_each_tracing_cpu(cpu)
1708 tracing_iter_reset(iter, cpu);
1709 } else
1710 tracing_iter_reset(iter, cpu_file);
1711
1712 ftrace_enable_cpu();
1713
1714 iter->leftover = 0;
1715 for (p = iter; p && l < *pos; p = s_next(m, p, &l))
1716 ;
1717
1718 } else {
1719
1720
1721
1722
1723 if (iter->leftover)
1724 p = iter;
1725 else {
1726 l = *pos - 1;
1727 p = s_next(m, p, &l);
1728 }
1729 }
1730
1731 trace_event_read_lock();
1732 trace_access_lock(cpu_file);
1733 return p;
1734}
1735
1736static void s_stop(struct seq_file *m, void *p)
1737{
1738 struct trace_iterator *iter = m->private;
1739
1740 atomic_dec(&trace_record_cmdline_disabled);
1741 trace_access_unlock(iter->cpu_file);
1742 trace_event_read_unlock();
1743}
1744
1745static void print_lat_help_header(struct seq_file *m)
1746{
1747 seq_puts(m, "# _------=> CPU# \n");
1748 seq_puts(m, "# / _-----=> irqs-off \n");
1749 seq_puts(m, "# | / _----=> need-resched \n");
1750 seq_puts(m, "# || / _---=> hardirq/softirq \n");
1751 seq_puts(m, "# ||| / _--=> preempt-depth \n");
1752 seq_puts(m, "# |||| /_--=> lock-depth \n");
1753 seq_puts(m, "# |||||/ delay \n");
1754 seq_puts(m, "# cmd pid |||||| time | caller \n");
1755 seq_puts(m, "# \\ / |||||| \\ | / \n");
1756}
1757
1758static void print_func_help_header(struct seq_file *m)
1759{
1760 seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
1761 seq_puts(m, "# | | | | |\n");
1762}
1763
1764
1765void
1766print_trace_header(struct seq_file *m, struct trace_iterator *iter)
1767{
1768 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1769 struct trace_array *tr = iter->tr;
1770 struct trace_array_cpu *data = tr->data[tr->cpu];
1771 struct tracer *type = current_trace;
1772 unsigned long entries = 0;
1773 unsigned long total = 0;
1774 unsigned long count;
1775 const char *name = "preemption";
1776 int cpu;
1777
1778 if (type)
1779 name = type->name;
1780
1781
1782 for_each_tracing_cpu(cpu) {
1783 count = ring_buffer_entries_cpu(tr->buffer, cpu);
1784
1785
1786
1787
1788
1789 if (tr->data[cpu]->skipped_entries) {
1790 count -= tr->data[cpu]->skipped_entries;
1791
1792 total += count;
1793 } else
1794 total += count +
1795 ring_buffer_overrun_cpu(tr->buffer, cpu);
1796 entries += count;
1797 }
1798
1799 seq_printf(m, "# %s latency trace v1.1.5 on %s\n",
1800 name, UTS_RELEASE);
1801 seq_puts(m, "# -----------------------------------"
1802 "---------------------------------\n");
1803 seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |"
1804 " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
1805 nsecs_to_usecs(data->saved_latency),
1806 entries,
1807 total,
1808 tr->cpu,
1809#if defined(CONFIG_PREEMPT_NONE)
1810 "server",
1811#elif defined(CONFIG_PREEMPT_VOLUNTARY)
1812 "desktop",
1813#elif defined(CONFIG_PREEMPT)
1814 "preempt",
1815#else
1816 "unknown",
1817#endif
1818
1819 0, 0, 0, 0);
1820#ifdef CONFIG_SMP
1821 seq_printf(m, " #P:%d)\n", num_online_cpus());
1822#else
1823 seq_puts(m, ")\n");
1824#endif
1825 seq_puts(m, "# -----------------\n");
1826 seq_printf(m, "# | task: %.16s-%d "
1827 "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
1828 data->comm, data->pid, data->uid, data->nice,
1829 data->policy, data->rt_priority);
1830 seq_puts(m, "# -----------------\n");
1831
1832 if (data->critical_start) {
1833 seq_puts(m, "# => started at: ");
1834 seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
1835 trace_print_seq(m, &iter->seq);
1836 seq_puts(m, "\n# => ended at: ");
1837 seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
1838 trace_print_seq(m, &iter->seq);
1839 seq_puts(m, "\n#\n");
1840 }
1841
1842 seq_puts(m, "#\n");
1843}
1844
1845static void test_cpu_buff_start(struct trace_iterator *iter)
1846{
1847 struct trace_seq *s = &iter->seq;
1848
1849 if (!(trace_flags & TRACE_ITER_ANNOTATE))
1850 return;
1851
1852 if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
1853 return;
1854
1855 if (cpumask_test_cpu(iter->cpu, iter->started))
1856 return;
1857
1858 if (iter->tr->data[iter->cpu]->skipped_entries)
1859 return;
1860
1861 cpumask_set_cpu(iter->cpu, iter->started);
1862
1863
1864 if (iter->idx > 1)
1865 trace_seq_printf(s, "##### CPU %u buffer started ####\n",
1866 iter->cpu);
1867}
1868
1869static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
1870{
1871 struct trace_seq *s = &iter->seq;
1872 unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
1873 struct trace_entry *entry;
1874 struct trace_event *event;
1875
1876 entry = iter->ent;
1877
1878 test_cpu_buff_start(iter);
1879
1880 event = ftrace_find_event(entry->type);
1881
1882 if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
1883 if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
1884 if (!trace_print_lat_context(iter))
1885 goto partial;
1886 } else {
1887 if (!trace_print_context(iter))
1888 goto partial;
1889 }
1890 }
1891
1892 if (event)
1893 return event->funcs->trace(iter, sym_flags, event);
1894
1895 if (!trace_seq_printf(s, "Unknown type %d\n", entry->type))
1896 goto partial;
1897
1898 return TRACE_TYPE_HANDLED;
1899partial:
1900 return TRACE_TYPE_PARTIAL_LINE;
1901}
1902
1903static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
1904{
1905 struct trace_seq *s = &iter->seq;
1906 struct trace_entry *entry;
1907 struct trace_event *event;
1908
1909 entry = iter->ent;
1910
1911 if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
1912 if (!trace_seq_printf(s, "%d %d %llu ",
1913 entry->pid, iter->cpu, iter->ts))
1914 goto partial;
1915 }
1916
1917 event = ftrace_find_event(entry->type);
1918 if (event)
1919 return event->funcs->raw(iter, 0, event);
1920
1921 if (!trace_seq_printf(s, "%d ?\n", entry->type))
1922 goto partial;
1923
1924 return TRACE_TYPE_HANDLED;
1925partial:
1926 return TRACE_TYPE_PARTIAL_LINE;
1927}
1928
1929static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
1930{
1931 struct trace_seq *s = &iter->seq;
1932 unsigned char newline = '\n';
1933 struct trace_entry *entry;
1934 struct trace_event *event;
1935
1936 entry = iter->ent;
1937
1938 if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
1939 SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
1940 SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
1941 SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
1942 }
1943
1944 event = ftrace_find_event(entry->type);
1945 if (event) {
1946 enum print_line_t ret = event->funcs->hex(iter, 0, event);
1947 if (ret != TRACE_TYPE_HANDLED)
1948 return ret;
1949 }
1950
1951 SEQ_PUT_FIELD_RET(s, newline);
1952
1953 return TRACE_TYPE_HANDLED;
1954}
1955
1956static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
1957{
1958 struct trace_seq *s = &iter->seq;
1959 struct trace_entry *entry;
1960 struct trace_event *event;
1961
1962 entry = iter->ent;
1963
1964 if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
1965 SEQ_PUT_FIELD_RET(s, entry->pid);
1966 SEQ_PUT_FIELD_RET(s, iter->cpu);
1967 SEQ_PUT_FIELD_RET(s, iter->ts);
1968 }
1969
1970 event = ftrace_find_event(entry->type);
1971 return event ? event->funcs->binary(iter, 0, event) :
1972 TRACE_TYPE_HANDLED;
1973}
1974
1975int trace_empty(struct trace_iterator *iter)
1976{
1977 int cpu;
1978
1979
1980 if (iter->cpu_file != TRACE_PIPE_ALL_CPU) {
1981 cpu = iter->cpu_file;
1982 if (iter->buffer_iter[cpu]) {
1983 if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
1984 return 0;
1985 } else {
1986 if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
1987 return 0;
1988 }
1989 return 1;
1990 }
1991
1992 for_each_tracing_cpu(cpu) {
1993 if (iter->buffer_iter[cpu]) {
1994 if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
1995 return 0;
1996 } else {
1997 if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
1998 return 0;
1999 }
2000 }
2001
2002 return 1;
2003}
2004
2005
2006enum print_line_t print_trace_line(struct trace_iterator *iter)
2007{
2008 enum print_line_t ret;
2009
2010 if (iter->lost_events)
2011 trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
2012 iter->cpu, iter->lost_events);
2013
2014 if (iter->trace && iter->trace->print_line) {
2015 ret = iter->trace->print_line(iter);
2016 if (ret != TRACE_TYPE_UNHANDLED)
2017 return ret;
2018 }
2019
2020 if (iter->ent->type == TRACE_BPRINT &&
2021 trace_flags & TRACE_ITER_PRINTK &&
2022 trace_flags & TRACE_ITER_PRINTK_MSGONLY)
2023 return trace_print_bprintk_msg_only(iter);
2024
2025 if (iter->ent->type == TRACE_PRINT &&
2026 trace_flags & TRACE_ITER_PRINTK &&
2027 trace_flags & TRACE_ITER_PRINTK_MSGONLY)
2028 return trace_print_printk_msg_only(iter);
2029
2030 if (trace_flags & TRACE_ITER_BIN)
2031 return print_bin_fmt(iter);
2032
2033 if (trace_flags & TRACE_ITER_HEX)
2034 return print_hex_fmt(iter);
2035
2036 if (trace_flags & TRACE_ITER_RAW)
2037 return print_raw_fmt(iter);
2038
2039 return print_trace_fmt(iter);
2040}
2041
2042void trace_default_header(struct seq_file *m)
2043{
2044 struct trace_iterator *iter = m->private;
2045
2046 if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
2047
2048 if (trace_empty(iter))
2049 return;
2050 print_trace_header(m, iter);
2051 if (!(trace_flags & TRACE_ITER_VERBOSE))
2052 print_lat_help_header(m);
2053 } else {
2054 if (!(trace_flags & TRACE_ITER_VERBOSE))
2055 print_func_help_header(m);
2056 }
2057}
2058
2059static int s_show(struct seq_file *m, void *v)
2060{
2061 struct trace_iterator *iter = v;
2062 int ret;
2063
2064 if (iter->ent == NULL) {
2065 if (iter->tr) {
2066 seq_printf(m, "# tracer: %s\n", iter->trace->name);
2067 seq_puts(m, "#\n");
2068 }
2069 if (iter->trace && iter->trace->print_header)
2070 iter->trace->print_header(m);
2071 else
2072 trace_default_header(m);
2073
2074 } else if (iter->leftover) {
2075
2076
2077
2078
2079 ret = trace_print_seq(m, &iter->seq);
2080
2081
2082 iter->leftover = ret;
2083
2084 } else {
2085 print_trace_line(iter);
2086 ret = trace_print_seq(m, &iter->seq);
2087
2088
2089
2090
2091
2092
2093
2094 iter->leftover = ret;
2095 }
2096
2097 return 0;
2098}
2099
2100static const struct seq_operations tracer_seq_ops = {
2101 .start = s_start,
2102 .next = s_next,
2103 .stop = s_stop,
2104 .show = s_show,
2105};
2106
2107static struct trace_iterator *
2108__tracing_open(struct inode *inode, struct file *file)
2109{
2110 long cpu_file = (long) inode->i_private;
2111 void *fail_ret = ERR_PTR(-ENOMEM);
2112 struct trace_iterator *iter;
2113 struct seq_file *m;
2114 int cpu, ret;
2115
2116 if (tracing_disabled)
2117 return ERR_PTR(-ENODEV);
2118
2119 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2120 if (!iter)
2121 return ERR_PTR(-ENOMEM);
2122
2123
2124
2125
2126
2127 mutex_lock(&trace_types_lock);
2128 iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL);
2129 if (!iter->trace)
2130 goto fail;
2131
2132 if (current_trace)
2133 *iter->trace = *current_trace;
2134
2135 if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
2136 goto fail;
2137
2138 if (current_trace && current_trace->print_max)
2139 iter->tr = &max_tr;
2140 else
2141 iter->tr = &global_trace;
2142 iter->pos = -1;
2143 mutex_init(&iter->mutex);
2144 iter->cpu_file = cpu_file;
2145
2146
2147 if (iter->trace && iter->trace->open)
2148 iter->trace->open(iter);
2149
2150
2151 if (ring_buffer_overruns(iter->tr->buffer))
2152 iter->iter_flags |= TRACE_FILE_ANNOTATE;
2153
2154
2155 tracing_stop();
2156
2157 if (iter->cpu_file == TRACE_PIPE_ALL_CPU) {
2158 for_each_tracing_cpu(cpu) {
2159 iter->buffer_iter[cpu] =
2160 ring_buffer_read_prepare(iter->tr->buffer, cpu);
2161 }
2162 ring_buffer_read_prepare_sync();
2163 for_each_tracing_cpu(cpu) {
2164 ring_buffer_read_start(iter->buffer_iter[cpu]);
2165 tracing_iter_reset(iter, cpu);
2166 }
2167 } else {
2168 cpu = iter->cpu_file;
2169 iter->buffer_iter[cpu] =
2170 ring_buffer_read_prepare(iter->tr->buffer, cpu);
2171 ring_buffer_read_prepare_sync();
2172 ring_buffer_read_start(iter->buffer_iter[cpu]);
2173 tracing_iter_reset(iter, cpu);
2174 }
2175
2176 ret = seq_open(file, &tracer_seq_ops);
2177 if (ret < 0) {
2178 fail_ret = ERR_PTR(ret);
2179 goto fail_buffer;
2180 }
2181
2182 m = file->private_data;
2183 m->private = iter;
2184
2185 mutex_unlock(&trace_types_lock);
2186
2187 return iter;
2188
2189 fail_buffer:
2190 for_each_tracing_cpu(cpu) {
2191 if (iter->buffer_iter[cpu])
2192 ring_buffer_read_finish(iter->buffer_iter[cpu]);
2193 }
2194 free_cpumask_var(iter->started);
2195 tracing_start();
2196 fail:
2197 mutex_unlock(&trace_types_lock);
2198 kfree(iter->trace);
2199 kfree(iter);
2200
2201 return fail_ret;
2202}
2203
2204int tracing_open_generic(struct inode *inode, struct file *filp)
2205{
2206 if (tracing_disabled)
2207 return -ENODEV;
2208
2209 filp->private_data = inode->i_private;
2210 return 0;
2211}
2212
2213static int tracing_release(struct inode *inode, struct file *file)
2214{
2215 struct seq_file *m = file->private_data;
2216 struct trace_iterator *iter;
2217 int cpu;
2218
2219 if (!(file->f_mode & FMODE_READ))
2220 return 0;
2221
2222 iter = m->private;
2223
2224 mutex_lock(&trace_types_lock);
2225 for_each_tracing_cpu(cpu) {
2226 if (iter->buffer_iter[cpu])
2227 ring_buffer_read_finish(iter->buffer_iter[cpu]);
2228 }
2229
2230 if (iter->trace && iter->trace->close)
2231 iter->trace->close(iter);
2232
2233
2234 tracing_start();
2235 mutex_unlock(&trace_types_lock);
2236
2237 seq_release(inode, file);
2238 mutex_destroy(&iter->mutex);
2239 free_cpumask_var(iter->started);
2240 kfree(iter->trace);
2241 kfree(iter);
2242 return 0;
2243}
2244
2245static int tracing_open(struct inode *inode, struct file *file)
2246{
2247 struct trace_iterator *iter;
2248 int ret = 0;
2249
2250
2251 if ((file->f_mode & FMODE_WRITE) &&
2252 (file->f_flags & O_TRUNC)) {
2253 long cpu = (long) inode->i_private;
2254
2255 if (cpu == TRACE_PIPE_ALL_CPU)
2256 tracing_reset_online_cpus(&global_trace);
2257 else
2258 tracing_reset(&global_trace, cpu);
2259 }
2260
2261 if (file->f_mode & FMODE_READ) {
2262 iter = __tracing_open(inode, file);
2263 if (IS_ERR(iter))
2264 ret = PTR_ERR(iter);
2265 else if (trace_flags & TRACE_ITER_LATENCY_FMT)
2266 iter->iter_flags |= TRACE_FILE_LAT_FMT;
2267 }
2268 return ret;
2269}
2270
2271static void *
2272t_next(struct seq_file *m, void *v, loff_t *pos)
2273{
2274 struct tracer *t = v;
2275
2276 (*pos)++;
2277
2278 if (t)
2279 t = t->next;
2280
2281 return t;
2282}
2283
2284static void *t_start(struct seq_file *m, loff_t *pos)
2285{
2286 struct tracer *t;
2287 loff_t l = 0;
2288
2289 mutex_lock(&trace_types_lock);
2290 for (t = trace_types; t && l < *pos; t = t_next(m, t, &l))
2291 ;
2292
2293 return t;
2294}
2295
2296static void t_stop(struct seq_file *m, void *p)
2297{
2298 mutex_unlock(&trace_types_lock);
2299}
2300
2301static int t_show(struct seq_file *m, void *v)
2302{
2303 struct tracer *t = v;
2304
2305 if (!t)
2306 return 0;
2307
2308 seq_printf(m, "%s", t->name);
2309 if (t->next)
2310 seq_putc(m, ' ');
2311 else
2312 seq_putc(m, '\n');
2313
2314 return 0;
2315}
2316
2317static const struct seq_operations show_traces_seq_ops = {
2318 .start = t_start,
2319 .next = t_next,
2320 .stop = t_stop,
2321 .show = t_show,
2322};
2323
2324static int show_traces_open(struct inode *inode, struct file *file)
2325{
2326 if (tracing_disabled)
2327 return -ENODEV;
2328
2329 return seq_open(file, &show_traces_seq_ops);
2330}
2331
2332static ssize_t
2333tracing_write_stub(struct file *filp, const char __user *ubuf,
2334 size_t count, loff_t *ppos)
2335{
2336 return count;
2337}
2338
2339static loff_t tracing_seek(struct file *file, loff_t offset, int origin)
2340{
2341 if (file->f_mode & FMODE_READ)
2342 return seq_lseek(file, offset, origin);
2343 else
2344 return 0;
2345}
2346
2347static const struct file_operations tracing_fops = {
2348 .open = tracing_open,
2349 .read = seq_read,
2350 .write = tracing_write_stub,
2351 .llseek = tracing_seek,
2352 .release = tracing_release,
2353};
2354
2355static const struct file_operations show_traces_fops = {
2356 .open = show_traces_open,
2357 .read = seq_read,
2358 .release = seq_release,
2359 .llseek = seq_lseek,
2360};
2361
2362
2363
2364
2365static cpumask_var_t tracing_cpumask;
2366
2367
2368
2369
2370
2371static DEFINE_MUTEX(tracing_cpumask_update_lock);
2372
2373
2374
2375
2376
2377static char mask_str[NR_CPUS + 1];
2378
2379static ssize_t
2380tracing_cpumask_read(struct file *filp, char __user *ubuf,
2381 size_t count, loff_t *ppos)
2382{
2383 int len;
2384
2385 mutex_lock(&tracing_cpumask_update_lock);
2386
2387 len = cpumask_scnprintf(mask_str, count, tracing_cpumask);
2388 if (count - len < 2) {
2389 count = -EINVAL;
2390 goto out_err;
2391 }
2392 len += sprintf(mask_str + len, "\n");
2393 count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);
2394
2395out_err:
2396 mutex_unlock(&tracing_cpumask_update_lock);
2397
2398 return count;
2399}
2400
2401static ssize_t
2402tracing_cpumask_write(struct file *filp, const char __user *ubuf,
2403 size_t count, loff_t *ppos)
2404{
2405 int err, cpu;
2406 cpumask_var_t tracing_cpumask_new;
2407
2408 if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
2409 return -ENOMEM;
2410
2411 err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
2412 if (err)
2413 goto err_unlock;
2414
2415 mutex_lock(&tracing_cpumask_update_lock);
2416
2417 local_irq_disable();
2418 arch_spin_lock(&ftrace_max_lock);
2419 for_each_tracing_cpu(cpu) {
2420
2421
2422
2423
2424 if (cpumask_test_cpu(cpu, tracing_cpumask) &&
2425 !cpumask_test_cpu(cpu, tracing_cpumask_new)) {
2426 atomic_inc(&global_trace.data[cpu]->disabled);
2427 }
2428 if (!cpumask_test_cpu(cpu, tracing_cpumask) &&
2429 cpumask_test_cpu(cpu, tracing_cpumask_new)) {
2430 atomic_dec(&global_trace.data[cpu]->disabled);
2431 }
2432 }
2433 arch_spin_unlock(&ftrace_max_lock);
2434 local_irq_enable();
2435
2436 cpumask_copy(tracing_cpumask, tracing_cpumask_new);
2437
2438 mutex_unlock(&tracing_cpumask_update_lock);
2439 free_cpumask_var(tracing_cpumask_new);
2440
2441 return count;
2442
2443err_unlock:
2444 free_cpumask_var(tracing_cpumask_new);
2445
2446 return err;
2447}
2448
2449static const struct file_operations tracing_cpumask_fops = {
2450 .open = tracing_open_generic,
2451 .read = tracing_cpumask_read,
2452 .write = tracing_cpumask_write,
2453 .llseek = generic_file_llseek,
2454};
2455
2456static int tracing_trace_options_show(struct seq_file *m, void *v)
2457{
2458 struct tracer_opt *trace_opts;
2459 u32 tracer_flags;
2460 int i;
2461
2462 mutex_lock(&trace_types_lock);
2463 tracer_flags = current_trace->flags->val;
2464 trace_opts = current_trace->flags->opts;
2465
2466 for (i = 0; trace_options[i]; i++) {
2467 if (trace_flags & (1 << i))
2468 seq_printf(m, "%s\n", trace_options[i]);
2469 else
2470 seq_printf(m, "no%s\n", trace_options[i]);
2471 }
2472
2473 for (i = 0; trace_opts[i].name; i++) {
2474 if (tracer_flags & trace_opts[i].bit)
2475 seq_printf(m, "%s\n", trace_opts[i].name);
2476 else
2477 seq_printf(m, "no%s\n", trace_opts[i].name);
2478 }
2479 mutex_unlock(&trace_types_lock);
2480
2481 return 0;
2482}
2483
2484static int __set_tracer_option(struct tracer *trace,
2485 struct tracer_flags *tracer_flags,
2486 struct tracer_opt *opts, int neg)
2487{
2488 int ret;
2489
2490 ret = trace->set_flag(tracer_flags->val, opts->bit, !neg);
2491 if (ret)
2492 return ret;
2493
2494 if (neg)
2495 tracer_flags->val &= ~opts->bit;
2496 else
2497 tracer_flags->val |= opts->bit;
2498 return 0;
2499}
2500
2501
2502static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
2503{
2504 struct tracer_flags *tracer_flags = trace->flags;
2505 struct tracer_opt *opts = NULL;
2506 int i;
2507
2508 for (i = 0; tracer_flags->opts[i].name; i++) {
2509 opts = &tracer_flags->opts[i];
2510
2511 if (strcmp(cmp, opts->name) == 0)
2512 return __set_tracer_option(trace, trace->flags,
2513 opts, neg);
2514 }
2515
2516 return -EINVAL;
2517}
2518
2519static void set_tracer_flags(unsigned int mask, int enabled)
2520{
2521
2522 if (!!(trace_flags & mask) == !!enabled)
2523 return;
2524
2525 if (enabled)
2526 trace_flags |= mask;
2527 else
2528 trace_flags &= ~mask;
2529
2530 if (mask == TRACE_ITER_RECORD_CMD)
2531 trace_event_enable_cmd_record(enabled);
2532}
2533
2534static ssize_t
2535tracing_trace_options_write(struct file *filp, const char __user *ubuf,
2536 size_t cnt, loff_t *ppos)
2537{
2538 char buf[64];
2539 char *cmp;
2540 int neg = 0;
2541 int ret;
2542 int i;
2543
2544 if (cnt >= sizeof(buf))
2545 return -EINVAL;
2546
2547 if (copy_from_user(&buf, ubuf, cnt))
2548 return -EFAULT;
2549
2550 buf[cnt] = 0;
2551 cmp = strstrip(buf);
2552
2553 if (strncmp(cmp, "no", 2) == 0) {
2554 neg = 1;
2555 cmp += 2;
2556 }
2557
2558 for (i = 0; trace_options[i]; i++) {
2559 if (strcmp(cmp, trace_options[i]) == 0) {
2560 set_tracer_flags(1 << i, !neg);
2561 break;
2562 }
2563 }
2564
2565
2566 if (!trace_options[i]) {
2567 mutex_lock(&trace_types_lock);
2568 ret = set_tracer_option(current_trace, cmp, neg);
2569 mutex_unlock(&trace_types_lock);
2570 if (ret)
2571 return ret;
2572 }
2573
2574 *ppos += cnt;
2575
2576 return cnt;
2577}
2578
2579static int tracing_trace_options_open(struct inode *inode, struct file *file)
2580{
2581 if (tracing_disabled)
2582 return -ENODEV;
2583 return single_open(file, tracing_trace_options_show, NULL);
2584}
2585
2586static const struct file_operations tracing_iter_fops = {
2587 .open = tracing_trace_options_open,
2588 .read = seq_read,
2589 .llseek = seq_lseek,
2590 .release = single_release,
2591 .write = tracing_trace_options_write,
2592};
2593
2594static const char readme_msg[] =
2595 "tracing mini-HOWTO:\n\n"
2596 "# mount -t debugfs nodev /sys/kernel/debug\n\n"
2597 "# cat /sys/kernel/debug/tracing/available_tracers\n"
2598 "wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n"
2599 "# cat /sys/kernel/debug/tracing/current_tracer\n"
2600 "nop\n"
2601 "# echo sched_switch > /sys/kernel/debug/tracing/current_tracer\n"
2602 "# cat /sys/kernel/debug/tracing/current_tracer\n"
2603 "sched_switch\n"
2604 "# cat /sys/kernel/debug/tracing/trace_options\n"
2605 "noprint-parent nosym-offset nosym-addr noverbose\n"
2606 "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n"
2607 "# echo 1 > /sys/kernel/debug/tracing/tracing_enabled\n"
2608 "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n"
2609 "# echo 0 > /sys/kernel/debug/tracing/tracing_enabled\n"
2610;
2611
2612static ssize_t
2613tracing_readme_read(struct file *filp, char __user *ubuf,
2614 size_t cnt, loff_t *ppos)
2615{
2616 return simple_read_from_buffer(ubuf, cnt, ppos,
2617 readme_msg, strlen(readme_msg));
2618}
2619
2620static const struct file_operations tracing_readme_fops = {
2621 .open = tracing_open_generic,
2622 .read = tracing_readme_read,
2623 .llseek = generic_file_llseek,
2624};
2625
2626static ssize_t
2627tracing_saved_cmdlines_read(struct file *file, char __user *ubuf,
2628 size_t cnt, loff_t *ppos)
2629{
2630 char *buf_comm;
2631 char *file_buf;
2632 char *buf;
2633 int len = 0;
2634 int pid;
2635 int i;
2636
2637 file_buf = kmalloc(SAVED_CMDLINES*(16+TASK_COMM_LEN), GFP_KERNEL);
2638 if (!file_buf)
2639 return -ENOMEM;
2640
2641 buf_comm = kmalloc(TASK_COMM_LEN, GFP_KERNEL);
2642 if (!buf_comm) {
2643 kfree(file_buf);
2644 return -ENOMEM;
2645 }
2646
2647 buf = file_buf;
2648
2649 for (i = 0; i < SAVED_CMDLINES; i++) {
2650 int r;
2651
2652 pid = map_cmdline_to_pid[i];
2653 if (pid == -1 || pid == NO_CMDLINE_MAP)
2654 continue;
2655
2656 trace_find_cmdline(pid, buf_comm);
2657 r = sprintf(buf, "%d %s\n", pid, buf_comm);
2658 buf += r;
2659 len += r;
2660 }
2661
2662 len = simple_read_from_buffer(ubuf, cnt, ppos,
2663 file_buf, len);
2664
2665 kfree(file_buf);
2666 kfree(buf_comm);
2667
2668 return len;
2669}
2670
2671static const struct file_operations tracing_saved_cmdlines_fops = {
2672 .open = tracing_open_generic,
2673 .read = tracing_saved_cmdlines_read,
2674 .llseek = generic_file_llseek,
2675};
2676
2677static ssize_t
2678tracing_ctrl_read(struct file *filp, char __user *ubuf,
2679 size_t cnt, loff_t *ppos)
2680{
2681 char buf[64];
2682 int r;
2683
2684 r = sprintf(buf, "%u\n", tracer_enabled);
2685 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2686}
2687
2688static ssize_t
2689tracing_ctrl_write(struct file *filp, const char __user *ubuf,
2690 size_t cnt, loff_t *ppos)
2691{
2692 struct trace_array *tr = filp->private_data;
2693 char buf[64];
2694 unsigned long val;
2695 int ret;
2696
2697 if (cnt >= sizeof(buf))
2698 return -EINVAL;
2699
2700 if (copy_from_user(&buf, ubuf, cnt))
2701 return -EFAULT;
2702
2703 buf[cnt] = 0;
2704
2705 ret = strict_strtoul(buf, 10, &val);
2706 if (ret < 0)
2707 return ret;
2708
2709 val = !!val;
2710
2711 mutex_lock(&trace_types_lock);
2712 if (tracer_enabled ^ val) {
2713 if (val) {
2714 tracer_enabled = 1;
2715 if (current_trace->start)
2716 current_trace->start(tr);
2717 tracing_start();
2718 } else {
2719 tracer_enabled = 0;
2720 tracing_stop();
2721 if (current_trace->stop)
2722 current_trace->stop(tr);
2723 }
2724 }
2725 mutex_unlock(&trace_types_lock);
2726
2727 *ppos += cnt;
2728
2729 return cnt;
2730}
2731
2732static ssize_t
2733tracing_set_trace_read(struct file *filp, char __user *ubuf,
2734 size_t cnt, loff_t *ppos)
2735{
2736 char buf[MAX_TRACER_SIZE+2];
2737 int r;
2738
2739 mutex_lock(&trace_types_lock);
2740 if (current_trace)
2741 r = sprintf(buf, "%s\n", current_trace->name);
2742 else
2743 r = sprintf(buf, "\n");
2744 mutex_unlock(&trace_types_lock);
2745
2746 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2747}
2748
2749int tracer_init(struct tracer *t, struct trace_array *tr)
2750{
2751 tracing_reset_online_cpus(tr);
2752 return t->init(tr);
2753}
2754
2755static int tracing_resize_ring_buffer(unsigned long size)
2756{
2757 int ret;
2758
2759
2760
2761
2762
2763
2764 ring_buffer_expanded = 1;
2765
2766 ret = ring_buffer_resize(global_trace.buffer, size);
2767 if (ret < 0)
2768 return ret;
2769
2770 if (!current_trace->use_max_tr)
2771 goto out;
2772
2773 ret = ring_buffer_resize(max_tr.buffer, size);
2774 if (ret < 0) {
2775 int r;
2776
2777 r = ring_buffer_resize(global_trace.buffer,
2778 global_trace.entries);
2779 if (r < 0) {
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794 WARN_ON(1);
2795 tracing_disabled = 1;
2796 }
2797 return ret;
2798 }
2799
2800 max_tr.entries = size;
2801 out:
2802 global_trace.entries = size;
2803
2804 return ret;
2805}
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818int tracing_update_buffers(void)
2819{
2820 int ret = 0;
2821
2822 mutex_lock(&trace_types_lock);
2823 if (!ring_buffer_expanded)
2824 ret = tracing_resize_ring_buffer(trace_buf_size);
2825 mutex_unlock(&trace_types_lock);
2826
2827 return ret;
2828}
2829
2830struct trace_option_dentry;
2831
2832static struct trace_option_dentry *
2833create_trace_option_files(struct tracer *tracer);
2834
2835static void
2836destroy_trace_option_files(struct trace_option_dentry *topts);
2837
2838static int tracing_set_tracer(const char *buf)
2839{
2840 static struct trace_option_dentry *topts;
2841 struct trace_array *tr = &global_trace;
2842 struct tracer *t;
2843 int ret = 0;
2844
2845 mutex_lock(&trace_types_lock);
2846
2847 if (!ring_buffer_expanded) {
2848 ret = tracing_resize_ring_buffer(trace_buf_size);
2849 if (ret < 0)
2850 goto out;
2851 ret = 0;
2852 }
2853
2854 for (t = trace_types; t; t = t->next) {
2855 if (strcmp(t->name, buf) == 0)
2856 break;
2857 }
2858 if (!t) {
2859 ret = -EINVAL;
2860 goto out;
2861 }
2862 if (t == current_trace)
2863 goto out;
2864
2865 trace_branch_disable();
2866 if (current_trace && current_trace->reset)
2867 current_trace->reset(tr);
2868 if (current_trace && current_trace->use_max_tr) {
2869
2870
2871
2872
2873
2874 ring_buffer_resize(max_tr.buffer, 1);
2875 max_tr.entries = 1;
2876 }
2877 destroy_trace_option_files(topts);
2878
2879 current_trace = t;
2880
2881 topts = create_trace_option_files(current_trace);
2882 if (current_trace->use_max_tr) {
2883 ret = ring_buffer_resize(max_tr.buffer, global_trace.entries);
2884 if (ret < 0)
2885 goto out;
2886 max_tr.entries = global_trace.entries;
2887 }
2888
2889 if (t->init) {
2890 ret = tracer_init(t, tr);
2891 if (ret)
2892 goto out;
2893 }
2894
2895 trace_branch_enable(tr);
2896 out:
2897 mutex_unlock(&trace_types_lock);
2898
2899 return ret;
2900}
2901
2902static ssize_t
2903tracing_set_trace_write(struct file *filp, const char __user *ubuf,
2904 size_t cnt, loff_t *ppos)
2905{
2906 char buf[MAX_TRACER_SIZE+1];
2907 int i;
2908 size_t ret;
2909 int err;
2910
2911 ret = cnt;
2912
2913 if (cnt > MAX_TRACER_SIZE)
2914 cnt = MAX_TRACER_SIZE;
2915
2916 if (copy_from_user(&buf, ubuf, cnt))
2917 return -EFAULT;
2918
2919 buf[cnt] = 0;
2920
2921
2922 for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
2923 buf[i] = 0;
2924
2925 err = tracing_set_tracer(buf);
2926 if (err)
2927 return err;
2928
2929 *ppos += ret;
2930
2931 return ret;
2932}
2933
2934static ssize_t
2935tracing_max_lat_read(struct file *filp, char __user *ubuf,
2936 size_t cnt, loff_t *ppos)
2937{
2938 unsigned long *ptr = filp->private_data;
2939 char buf[64];
2940 int r;
2941
2942 r = snprintf(buf, sizeof(buf), "%ld\n",
2943 *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
2944 if (r > sizeof(buf))
2945 r = sizeof(buf);
2946 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
2947}
2948
2949static ssize_t
2950tracing_max_lat_write(struct file *filp, const char __user *ubuf,
2951 size_t cnt, loff_t *ppos)
2952{
2953 unsigned long *ptr = filp->private_data;
2954 char buf[64];
2955 unsigned long val;
2956 int ret;
2957
2958 if (cnt >= sizeof(buf))
2959 return -EINVAL;
2960
2961 if (copy_from_user(&buf, ubuf, cnt))
2962 return -EFAULT;
2963
2964 buf[cnt] = 0;
2965
2966 ret = strict_strtoul(buf, 10, &val);
2967 if (ret < 0)
2968 return ret;
2969
2970 *ptr = val * 1000;
2971
2972 return cnt;
2973}
2974
2975static int tracing_open_pipe(struct inode *inode, struct file *filp)
2976{
2977 long cpu_file = (long) inode->i_private;
2978 struct trace_iterator *iter;
2979 int ret = 0;
2980
2981 if (tracing_disabled)
2982 return -ENODEV;
2983
2984 mutex_lock(&trace_types_lock);
2985
2986
2987 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2988 if (!iter) {
2989 ret = -ENOMEM;
2990 goto out;
2991 }
2992
2993
2994
2995
2996
2997 iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL);
2998 if (!iter->trace) {
2999 ret = -ENOMEM;
3000 goto fail;
3001 }
3002 if (current_trace)
3003 *iter->trace = *current_trace;
3004
3005 if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
3006 ret = -ENOMEM;
3007 goto fail;
3008 }
3009
3010
3011 cpumask_setall(iter->started);
3012
3013 if (trace_flags & TRACE_ITER_LATENCY_FMT)
3014 iter->iter_flags |= TRACE_FILE_LAT_FMT;
3015
3016 iter->cpu_file = cpu_file;
3017 iter->tr = &global_trace;
3018 mutex_init(&iter->mutex);
3019 filp->private_data = iter;
3020
3021 if (iter->trace->pipe_open)
3022 iter->trace->pipe_open(iter);
3023
3024 nonseekable_open(inode, filp);
3025out:
3026 mutex_unlock(&trace_types_lock);
3027 return ret;
3028
3029fail:
3030 kfree(iter->trace);
3031 kfree(iter);
3032 mutex_unlock(&trace_types_lock);
3033 return ret;
3034}
3035
3036static int tracing_release_pipe(struct inode *inode, struct file *file)
3037{
3038 struct trace_iterator *iter = file->private_data;
3039
3040 mutex_lock(&trace_types_lock);
3041
3042 if (iter->trace->pipe_close)
3043 iter->trace->pipe_close(iter);
3044
3045 mutex_unlock(&trace_types_lock);
3046
3047 free_cpumask_var(iter->started);
3048 mutex_destroy(&iter->mutex);
3049 kfree(iter->trace);
3050 kfree(iter);
3051
3052 return 0;
3053}
3054
3055static unsigned int
3056tracing_poll_pipe(struct file *filp, poll_table *poll_table)
3057{
3058 struct trace_iterator *iter = filp->private_data;
3059
3060 if (trace_flags & TRACE_ITER_BLOCK) {
3061
3062
3063
3064 return POLLIN | POLLRDNORM;
3065 } else {
3066 if (!trace_empty(iter))
3067 return POLLIN | POLLRDNORM;
3068 poll_wait(filp, &trace_wait, poll_table);
3069 if (!trace_empty(iter))
3070 return POLLIN | POLLRDNORM;
3071
3072 return 0;
3073 }
3074}
3075
3076
3077void default_wait_pipe(struct trace_iterator *iter)
3078{
3079 DEFINE_WAIT(wait);
3080
3081 prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE);
3082
3083 if (trace_empty(iter))
3084 schedule();
3085
3086 finish_wait(&trace_wait, &wait);
3087}
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101void poll_wait_pipe(struct trace_iterator *iter)
3102{
3103 set_current_state(TASK_INTERRUPTIBLE);
3104
3105 schedule_timeout(HZ / 10);
3106}
3107
3108
3109static int tracing_wait_pipe(struct file *filp)
3110{
3111 struct trace_iterator *iter = filp->private_data;
3112
3113 while (trace_empty(iter)) {
3114
3115 if ((filp->f_flags & O_NONBLOCK)) {
3116 return -EAGAIN;
3117 }
3118
3119 mutex_unlock(&iter->mutex);
3120
3121 iter->trace->wait_pipe(iter);
3122
3123 mutex_lock(&iter->mutex);
3124
3125 if (signal_pending(current))
3126 return -EINTR;
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137 if (!tracer_enabled && iter->pos)
3138 break;
3139 }
3140
3141 return 1;
3142}
3143
3144
3145
3146
3147static ssize_t
3148tracing_read_pipe(struct file *filp, char __user *ubuf,
3149 size_t cnt, loff_t *ppos)
3150{
3151 struct trace_iterator *iter = filp->private_data;
3152 static struct tracer *old_tracer;
3153 ssize_t sret;
3154
3155
3156 sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
3157 if (sret != -EBUSY)
3158 return sret;
3159
3160 trace_seq_init(&iter->seq);
3161
3162
3163 mutex_lock(&trace_types_lock);
3164 if (unlikely(old_tracer != current_trace && current_trace)) {
3165 old_tracer = current_trace;
3166 *iter->trace = *current_trace;
3167 }
3168 mutex_unlock(&trace_types_lock);
3169
3170
3171
3172
3173
3174
3175 mutex_lock(&iter->mutex);
3176 if (iter->trace->read) {
3177 sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
3178 if (sret)
3179 goto out;
3180 }
3181
3182waitagain:
3183 sret = tracing_wait_pipe(filp);
3184 if (sret <= 0)
3185 goto out;
3186
3187
3188 if (trace_empty(iter)) {
3189 sret = 0;
3190 goto out;
3191 }
3192
3193 if (cnt >= PAGE_SIZE)
3194 cnt = PAGE_SIZE - 1;
3195
3196
3197 memset(&iter->seq, 0,
3198 sizeof(struct trace_iterator) -
3199 offsetof(struct trace_iterator, seq));
3200 iter->pos = -1;
3201
3202 trace_event_read_lock();
3203 trace_access_lock(iter->cpu_file);
3204 while (trace_find_next_entry_inc(iter) != NULL) {
3205 enum print_line_t ret;
3206 int len = iter->seq.len;
3207
3208 ret = print_trace_line(iter);
3209 if (ret == TRACE_TYPE_PARTIAL_LINE) {
3210
3211 iter->seq.len = len;
3212 break;
3213 }
3214 if (ret != TRACE_TYPE_NO_CONSUME)
3215 trace_consume(iter);
3216
3217 if (iter->seq.len >= cnt)
3218 break;
3219 }
3220 trace_access_unlock(iter->cpu_file);
3221 trace_event_read_unlock();
3222
3223
3224 sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
3225 if (iter->seq.readpos >= iter->seq.len)
3226 trace_seq_init(&iter->seq);
3227
3228
3229
3230
3231
3232 if (sret == -EBUSY)
3233 goto waitagain;
3234
3235out:
3236 mutex_unlock(&iter->mutex);
3237
3238 return sret;
3239}
3240
3241static void tracing_pipe_buf_release(struct pipe_inode_info *pipe,
3242 struct pipe_buffer *buf)
3243{
3244 __free_page(buf->page);
3245}
3246
3247static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
3248 unsigned int idx)
3249{
3250 __free_page(spd->pages[idx]);
3251}
3252
3253static const struct pipe_buf_operations tracing_pipe_buf_ops = {
3254 .can_merge = 0,
3255 .map = generic_pipe_buf_map,
3256 .unmap = generic_pipe_buf_unmap,
3257 .confirm = generic_pipe_buf_confirm,
3258 .release = tracing_pipe_buf_release,
3259 .steal = generic_pipe_buf_steal,
3260 .get = generic_pipe_buf_get,
3261};
3262
3263static size_t
3264tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
3265{
3266 size_t count;
3267 int ret;
3268
3269
3270 for (;;) {
3271 count = iter->seq.len;
3272 ret = print_trace_line(iter);
3273 count = iter->seq.len - count;
3274 if (rem < count) {
3275 rem = 0;
3276 iter->seq.len -= count;
3277 break;
3278 }
3279 if (ret == TRACE_TYPE_PARTIAL_LINE) {
3280 iter->seq.len -= count;
3281 break;
3282 }
3283
3284 if (ret != TRACE_TYPE_NO_CONSUME)
3285 trace_consume(iter);
3286 rem -= count;
3287 if (!trace_find_next_entry_inc(iter)) {
3288 rem = 0;
3289 iter->ent = NULL;
3290 break;
3291 }
3292 }
3293
3294 return rem;
3295}
3296
3297static ssize_t tracing_splice_read_pipe(struct file *filp,
3298 loff_t *ppos,
3299 struct pipe_inode_info *pipe,
3300 size_t len,
3301 unsigned int flags)
3302{
3303 struct page *pages_def[PIPE_DEF_BUFFERS];
3304 struct partial_page partial_def[PIPE_DEF_BUFFERS];
3305 struct trace_iterator *iter = filp->private_data;
3306 struct splice_pipe_desc spd = {
3307 .pages = pages_def,
3308 .partial = partial_def,
3309 .nr_pages = 0,
3310 .flags = flags,
3311 .ops = &tracing_pipe_buf_ops,
3312 .spd_release = tracing_spd_release_pipe,
3313 };
3314 static struct tracer *old_tracer;
3315 ssize_t ret;
3316 size_t rem;
3317 unsigned int i;
3318
3319 if (splice_grow_spd(pipe, &spd))
3320 return -ENOMEM;
3321
3322
3323 mutex_lock(&trace_types_lock);
3324 if (unlikely(old_tracer != current_trace && current_trace)) {
3325 old_tracer = current_trace;
3326 *iter->trace = *current_trace;
3327 }
3328 mutex_unlock(&trace_types_lock);
3329
3330 mutex_lock(&iter->mutex);
3331
3332 if (iter->trace->splice_read) {
3333 ret = iter->trace->splice_read(iter, filp,
3334 ppos, pipe, len, flags);
3335 if (ret)
3336 goto out_err;
3337 }
3338
3339 ret = tracing_wait_pipe(filp);
3340 if (ret <= 0)
3341 goto out_err;
3342
3343 if (!iter->ent && !trace_find_next_entry_inc(iter)) {
3344 ret = -EFAULT;
3345 goto out_err;
3346 }
3347
3348 trace_event_read_lock();
3349 trace_access_lock(iter->cpu_file);
3350
3351
3352 for (i = 0, rem = len; i < pipe->buffers && rem; i++) {
3353 spd.pages[i] = alloc_page(GFP_KERNEL);
3354 if (!spd.pages[i])
3355 break;
3356
3357 rem = tracing_fill_pipe_page(rem, iter);
3358
3359
3360 ret = trace_seq_to_buffer(&iter->seq,
3361 page_address(spd.pages[i]),
3362 iter->seq.len);
3363 if (ret < 0) {
3364 __free_page(spd.pages[i]);
3365 break;
3366 }
3367 spd.partial[i].offset = 0;
3368 spd.partial[i].len = iter->seq.len;
3369
3370 trace_seq_init(&iter->seq);
3371 }
3372
3373 trace_access_unlock(iter->cpu_file);
3374 trace_event_read_unlock();
3375 mutex_unlock(&iter->mutex);
3376
3377 spd.nr_pages = i;
3378
3379 ret = splice_to_pipe(pipe, &spd);
3380out:
3381 splice_shrink_spd(pipe, &spd);
3382 return ret;
3383
3384out_err:
3385 mutex_unlock(&iter->mutex);
3386 goto out;
3387}
3388
3389static ssize_t
3390tracing_entries_read(struct file *filp, char __user *ubuf,
3391 size_t cnt, loff_t *ppos)
3392{
3393 struct trace_array *tr = filp->private_data;
3394 char buf[96];
3395 int r;
3396
3397 mutex_lock(&trace_types_lock);
3398 if (!ring_buffer_expanded)
3399 r = sprintf(buf, "%lu (expanded: %lu)\n",
3400 tr->entries >> 10,
3401 trace_buf_size >> 10);
3402 else
3403 r = sprintf(buf, "%lu\n", tr->entries >> 10);
3404 mutex_unlock(&trace_types_lock);
3405
3406 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
3407}
3408
3409static ssize_t
3410tracing_entries_write(struct file *filp, const char __user *ubuf,
3411 size_t cnt, loff_t *ppos)
3412{
3413 unsigned long val;
3414 char buf[64];
3415 int ret, cpu;
3416
3417 if (cnt >= sizeof(buf))
3418 return -EINVAL;
3419
3420 if (copy_from_user(&buf, ubuf, cnt))
3421 return -EFAULT;
3422
3423 buf[cnt] = 0;
3424
3425 ret = strict_strtoul(buf, 10, &val);
3426 if (ret < 0)
3427 return ret;
3428
3429
3430 if (!val)
3431 return -EINVAL;
3432
3433 mutex_lock(&trace_types_lock);
3434
3435 tracing_stop();
3436
3437
3438 for_each_tracing_cpu(cpu) {
3439 if (global_trace.data[cpu])
3440 atomic_inc(&global_trace.data[cpu]->disabled);
3441 if (max_tr.data[cpu])
3442 atomic_inc(&max_tr.data[cpu]->disabled);
3443 }
3444
3445
3446 val <<= 10;
3447
3448 if (val != global_trace.entries) {
3449 ret = tracing_resize_ring_buffer(val);
3450 if (ret < 0) {
3451 cnt = ret;
3452 goto out;
3453 }
3454 }
3455
3456 *ppos += cnt;
3457
3458
3459 if (tracing_disabled)
3460 cnt = -ENOMEM;
3461 out:
3462 for_each_tracing_cpu(cpu) {
3463 if (global_trace.data[cpu])
3464 atomic_dec(&global_trace.data[cpu]->disabled);
3465 if (max_tr.data[cpu])
3466 atomic_dec(&max_tr.data[cpu]->disabled);
3467 }
3468
3469 tracing_start();
3470 mutex_unlock(&trace_types_lock);
3471
3472 return cnt;
3473}
3474
3475static int mark_printk(const char *fmt, ...)
3476{
3477 int ret;
3478 va_list args;
3479 va_start(args, fmt);
3480 ret = trace_vprintk(0, fmt, args);
3481 va_end(args);
3482 return ret;
3483}
3484
3485static ssize_t
3486tracing_mark_write(struct file *filp, const char __user *ubuf,
3487 size_t cnt, loff_t *fpos)
3488{
3489 char *buf;
3490 size_t written;
3491
3492 if (tracing_disabled)
3493 return -EINVAL;
3494
3495 if (cnt > TRACE_BUF_SIZE)
3496 cnt = TRACE_BUF_SIZE;
3497
3498 buf = kmalloc(cnt + 2, GFP_KERNEL);
3499 if (buf == NULL)
3500 return -ENOMEM;
3501
3502 if (copy_from_user(buf, ubuf, cnt)) {
3503 kfree(buf);
3504 return -EFAULT;
3505 }
3506 if (buf[cnt-1] != '\n') {
3507 buf[cnt] = '\n';
3508 buf[cnt+1] = '\0';
3509 } else
3510 buf[cnt] = '\0';
3511
3512 written = mark_printk("%s", buf);
3513 kfree(buf);
3514 *fpos += written;
3515
3516
3517 if (written > cnt)
3518 written = cnt;
3519
3520 return written;
3521}
3522
3523static int tracing_clock_show(struct seq_file *m, void *v)
3524{
3525 int i;
3526
3527 for (i = 0; i < ARRAY_SIZE(trace_clocks); i++)
3528 seq_printf(m,
3529 "%s%s%s%s", i ? " " : "",
3530 i == trace_clock_id ? "[" : "", trace_clocks[i].name,
3531 i == trace_clock_id ? "]" : "");
3532 seq_putc(m, '\n');
3533
3534 return 0;
3535}
3536
3537static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
3538 size_t cnt, loff_t *fpos)
3539{
3540 char buf[64];
3541 const char *clockstr;
3542 int i;
3543
3544 if (cnt >= sizeof(buf))
3545 return -EINVAL;
3546
3547 if (copy_from_user(&buf, ubuf, cnt))
3548 return -EFAULT;
3549
3550 buf[cnt] = 0;
3551
3552 clockstr = strstrip(buf);
3553
3554 for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) {
3555 if (strcmp(trace_clocks[i].name, clockstr) == 0)
3556 break;
3557 }
3558 if (i == ARRAY_SIZE(trace_clocks))
3559 return -EINVAL;
3560
3561 trace_clock_id = i;
3562
3563 mutex_lock(&trace_types_lock);
3564
3565 ring_buffer_set_clock(global_trace.buffer, trace_clocks[i].func);
3566 if (max_tr.buffer)
3567 ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func);
3568
3569 mutex_unlock(&trace_types_lock);
3570
3571 *fpos += cnt;
3572
3573 return cnt;
3574}
3575
3576static int tracing_clock_open(struct inode *inode, struct file *file)
3577{
3578 if (tracing_disabled)
3579 return -ENODEV;
3580 return single_open(file, tracing_clock_show, NULL);
3581}
3582
3583static const struct file_operations tracing_max_lat_fops = {
3584 .open = tracing_open_generic,
3585 .read = tracing_max_lat_read,
3586 .write = tracing_max_lat_write,
3587 .llseek = generic_file_llseek,
3588};
3589
3590static const struct file_operations tracing_ctrl_fops = {
3591 .open = tracing_open_generic,
3592 .read = tracing_ctrl_read,
3593 .write = tracing_ctrl_write,
3594 .llseek = generic_file_llseek,
3595};
3596
3597static const struct file_operations set_tracer_fops = {
3598 .open = tracing_open_generic,
3599 .read = tracing_set_trace_read,
3600 .write = tracing_set_trace_write,
3601 .llseek = generic_file_llseek,
3602};
3603
3604static const struct file_operations tracing_pipe_fops = {
3605 .open = tracing_open_pipe,
3606 .poll = tracing_poll_pipe,
3607 .read = tracing_read_pipe,
3608 .splice_read = tracing_splice_read_pipe,
3609 .release = tracing_release_pipe,
3610 .llseek = no_llseek,
3611};
3612
3613static const struct file_operations tracing_entries_fops = {
3614 .open = tracing_open_generic,
3615 .read = tracing_entries_read,
3616 .write = tracing_entries_write,
3617 .llseek = generic_file_llseek,
3618};
3619
3620static const struct file_operations tracing_mark_fops = {
3621 .open = tracing_open_generic,
3622 .write = tracing_mark_write,
3623 .llseek = generic_file_llseek,
3624};
3625
3626static const struct file_operations trace_clock_fops = {
3627 .open = tracing_clock_open,
3628 .read = seq_read,
3629 .llseek = seq_lseek,
3630 .release = single_release,
3631 .write = tracing_clock_write,
3632};
3633
3634struct ftrace_buffer_info {
3635 struct trace_array *tr;
3636 void *spare;
3637 int cpu;
3638 unsigned int read;
3639};
3640
3641static int tracing_buffers_open(struct inode *inode, struct file *filp)
3642{
3643 int cpu = (int)(long)inode->i_private;
3644 struct ftrace_buffer_info *info;
3645
3646 if (tracing_disabled)
3647 return -ENODEV;
3648
3649 info = kzalloc(sizeof(*info), GFP_KERNEL);
3650 if (!info)
3651 return -ENOMEM;
3652
3653 info->tr = &global_trace;
3654 info->cpu = cpu;
3655 info->spare = NULL;
3656
3657 info->read = (unsigned int)-1;
3658
3659 filp->private_data = info;
3660
3661 return nonseekable_open(inode, filp);
3662}
3663
3664static ssize_t
3665tracing_buffers_read(struct file *filp, char __user *ubuf,
3666 size_t count, loff_t *ppos)
3667{
3668 struct ftrace_buffer_info *info = filp->private_data;
3669 ssize_t ret;
3670 size_t size;
3671
3672 if (!count)
3673 return 0;
3674
3675 if (!info->spare)
3676 info->spare = ring_buffer_alloc_read_page(info->tr->buffer);
3677 if (!info->spare)
3678 return -ENOMEM;
3679
3680
3681 if (info->read < PAGE_SIZE)
3682 goto read;
3683
3684 info->read = 0;
3685
3686 trace_access_lock(info->cpu);
3687 ret = ring_buffer_read_page(info->tr->buffer,
3688 &info->spare,
3689 count,
3690 info->cpu, 0);
3691 trace_access_unlock(info->cpu);
3692 if (ret < 0)
3693 return 0;
3694
3695read:
3696 size = PAGE_SIZE - info->read;
3697 if (size > count)
3698 size = count;
3699
3700 ret = copy_to_user(ubuf, info->spare + info->read, size);
3701 if (ret == size)
3702 return -EFAULT;
3703 size -= ret;
3704
3705 *ppos += size;
3706 info->read += size;
3707
3708 return size;
3709}
3710
3711static int tracing_buffers_release(struct inode *inode, struct file *file)
3712{
3713 struct ftrace_buffer_info *info = file->private_data;
3714
3715 if (info->spare)
3716 ring_buffer_free_read_page(info->tr->buffer, info->spare);
3717 kfree(info);
3718
3719 return 0;
3720}
3721
3722struct buffer_ref {
3723 struct ring_buffer *buffer;
3724 void *page;
3725 int ref;
3726};
3727
3728static void buffer_pipe_buf_release(struct pipe_inode_info *pipe,
3729 struct pipe_buffer *buf)
3730{
3731 struct buffer_ref *ref = (struct buffer_ref *)buf->private;
3732
3733 if (--ref->ref)
3734 return;
3735
3736 ring_buffer_free_read_page(ref->buffer, ref->page);
3737 kfree(ref);
3738 buf->private = 0;
3739}
3740
3741static int buffer_pipe_buf_steal(struct pipe_inode_info *pipe,
3742 struct pipe_buffer *buf)
3743{
3744 return 1;
3745}
3746
3747static void buffer_pipe_buf_get(struct pipe_inode_info *pipe,
3748 struct pipe_buffer *buf)
3749{
3750 struct buffer_ref *ref = (struct buffer_ref *)buf->private;
3751
3752 ref->ref++;
3753}
3754
3755
3756static const struct pipe_buf_operations buffer_pipe_buf_ops = {
3757 .can_merge = 0,
3758 .map = generic_pipe_buf_map,
3759 .unmap = generic_pipe_buf_unmap,
3760 .confirm = generic_pipe_buf_confirm,
3761 .release = buffer_pipe_buf_release,
3762 .steal = buffer_pipe_buf_steal,
3763 .get = buffer_pipe_buf_get,
3764};
3765
3766
3767
3768
3769
3770static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i)
3771{
3772 struct buffer_ref *ref =
3773 (struct buffer_ref *)spd->partial[i].private;
3774
3775 if (--ref->ref)
3776 return;
3777
3778 ring_buffer_free_read_page(ref->buffer, ref->page);
3779 kfree(ref);
3780 spd->partial[i].private = 0;
3781}
3782
3783static ssize_t
3784tracing_buffers_splice_read(struct file *file, loff_t *ppos,
3785 struct pipe_inode_info *pipe, size_t len,
3786 unsigned int flags)
3787{
3788 struct ftrace_buffer_info *info = file->private_data;
3789 struct partial_page partial_def[PIPE_DEF_BUFFERS];
3790 struct page *pages_def[PIPE_DEF_BUFFERS];
3791 struct splice_pipe_desc spd = {
3792 .pages = pages_def,
3793 .partial = partial_def,
3794 .flags = flags,
3795 .ops = &buffer_pipe_buf_ops,
3796 .spd_release = buffer_spd_release,
3797 };
3798 struct buffer_ref *ref;
3799 int entries, size, i;
3800 size_t ret;
3801
3802 if (splice_grow_spd(pipe, &spd))
3803 return -ENOMEM;
3804
3805 if (*ppos & (PAGE_SIZE - 1)) {
3806 WARN_ONCE(1, "Ftrace: previous read must page-align\n");
3807 ret = -EINVAL;
3808 goto out;
3809 }
3810
3811 if (len & (PAGE_SIZE - 1)) {
3812 WARN_ONCE(1, "Ftrace: splice_read should page-align\n");
3813 if (len < PAGE_SIZE) {
3814 ret = -EINVAL;
3815 goto out;
3816 }
3817 len &= PAGE_MASK;
3818 }
3819
3820 trace_access_lock(info->cpu);
3821 entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu);
3822
3823 for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) {
3824 struct page *page;
3825 int r;
3826
3827 ref = kzalloc(sizeof(*ref), GFP_KERNEL);
3828 if (!ref)
3829 break;
3830
3831 ref->ref = 1;
3832 ref->buffer = info->tr->buffer;
3833 ref->page = ring_buffer_alloc_read_page(ref->buffer);
3834 if (!ref->page) {
3835 kfree(ref);
3836 break;
3837 }
3838
3839 r = ring_buffer_read_page(ref->buffer, &ref->page,
3840 len, info->cpu, 1);
3841 if (r < 0) {
3842 ring_buffer_free_read_page(ref->buffer,
3843 ref->page);
3844 kfree(ref);
3845 break;
3846 }
3847
3848
3849
3850
3851
3852 size = ring_buffer_page_len(ref->page);
3853 if (size < PAGE_SIZE)
3854 memset(ref->page + size, 0, PAGE_SIZE - size);
3855
3856 page = virt_to_page(ref->page);
3857
3858 spd.pages[i] = page;
3859 spd.partial[i].len = PAGE_SIZE;
3860 spd.partial[i].offset = 0;
3861 spd.partial[i].private = (unsigned long)ref;
3862 spd.nr_pages++;
3863 *ppos += PAGE_SIZE;
3864
3865 entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu);
3866 }
3867
3868 trace_access_unlock(info->cpu);
3869 spd.nr_pages = i;
3870
3871
3872 if (!spd.nr_pages) {
3873 if (flags & SPLICE_F_NONBLOCK)
3874 ret = -EAGAIN;
3875 else
3876 ret = 0;
3877
3878 goto out;
3879 }
3880
3881 ret = splice_to_pipe(pipe, &spd);
3882 splice_shrink_spd(pipe, &spd);
3883out:
3884 return ret;
3885}
3886
3887static const struct file_operations tracing_buffers_fops = {
3888 .open = tracing_buffers_open,
3889 .read = tracing_buffers_read,
3890 .release = tracing_buffers_release,
3891 .splice_read = tracing_buffers_splice_read,
3892 .llseek = no_llseek,
3893};
3894
3895static ssize_t
3896tracing_stats_read(struct file *filp, char __user *ubuf,
3897 size_t count, loff_t *ppos)
3898{
3899 unsigned long cpu = (unsigned long)filp->private_data;
3900 struct trace_array *tr = &global_trace;
3901 struct trace_seq *s;
3902 unsigned long cnt;
3903
3904 s = kmalloc(sizeof(*s), GFP_KERNEL);
3905 if (!s)
3906 return -ENOMEM;
3907
3908 trace_seq_init(s);
3909
3910 cnt = ring_buffer_entries_cpu(tr->buffer, cpu);
3911 trace_seq_printf(s, "entries: %ld\n", cnt);
3912
3913 cnt = ring_buffer_overrun_cpu(tr->buffer, cpu);
3914 trace_seq_printf(s, "overrun: %ld\n", cnt);
3915
3916 cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu);
3917 trace_seq_printf(s, "commit overrun: %ld\n", cnt);
3918
3919 count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);
3920
3921 kfree(s);
3922
3923 return count;
3924}
3925
3926static const struct file_operations tracing_stats_fops = {
3927 .open = tracing_open_generic,
3928 .read = tracing_stats_read,
3929 .llseek = generic_file_llseek,
3930};
3931
3932#ifdef CONFIG_DYNAMIC_FTRACE
3933
3934int __weak ftrace_arch_read_dyn_info(char *buf, int size)
3935{
3936 return 0;
3937}
3938
3939static ssize_t
3940tracing_read_dyn_info(struct file *filp, char __user *ubuf,
3941 size_t cnt, loff_t *ppos)
3942{
3943 static char ftrace_dyn_info_buffer[1024];
3944 static DEFINE_MUTEX(dyn_info_mutex);
3945 unsigned long *p = filp->private_data;
3946 char *buf = ftrace_dyn_info_buffer;
3947 int size = ARRAY_SIZE(ftrace_dyn_info_buffer);
3948 int r;
3949
3950 mutex_lock(&dyn_info_mutex);
3951 r = sprintf(buf, "%ld ", *p);
3952
3953 r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r);
3954 buf[r++] = '\n';
3955
3956 r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
3957
3958 mutex_unlock(&dyn_info_mutex);
3959
3960 return r;
3961}
3962
3963static const struct file_operations tracing_dyn_info_fops = {
3964 .open = tracing_open_generic,
3965 .read = tracing_read_dyn_info,
3966 .llseek = generic_file_llseek,
3967};
3968#endif
3969
3970static struct dentry *d_tracer;
3971
3972struct dentry *tracing_init_dentry(void)
3973{
3974 static int once;
3975
3976 if (d_tracer)
3977 return d_tracer;
3978
3979 if (!debugfs_initialized())
3980 return NULL;
3981
3982 d_tracer = debugfs_create_dir("tracing", NULL);
3983
3984 if (!d_tracer && !once) {
3985 once = 1;
3986 pr_warning("Could not create debugfs directory 'tracing'\n");
3987 return NULL;
3988 }
3989
3990 return d_tracer;
3991}
3992
3993static struct dentry *d_percpu;
3994
3995struct dentry *tracing_dentry_percpu(void)
3996{
3997 static int once;
3998 struct dentry *d_tracer;
3999
4000 if (d_percpu)
4001 return d_percpu;
4002
4003 d_tracer = tracing_init_dentry();
4004
4005 if (!d_tracer)
4006 return NULL;
4007
4008 d_percpu = debugfs_create_dir("per_cpu", d_tracer);
4009
4010 if (!d_percpu && !once) {
4011 once = 1;
4012 pr_warning("Could not create debugfs directory 'per_cpu'\n");
4013 return NULL;
4014 }
4015
4016 return d_percpu;
4017}
4018
4019static void tracing_init_debugfs_percpu(long cpu)
4020{
4021 struct dentry *d_percpu = tracing_dentry_percpu();
4022 struct dentry *d_cpu;
4023 char cpu_dir[30];
4024
4025 snprintf(cpu_dir, 30, "cpu%ld", cpu);
4026 d_cpu = debugfs_create_dir(cpu_dir, d_percpu);
4027 if (!d_cpu) {
4028 pr_warning("Could not create debugfs '%s' entry\n", cpu_dir);
4029 return;
4030 }
4031
4032
4033 trace_create_file("trace_pipe", 0444, d_cpu,
4034 (void *) cpu, &tracing_pipe_fops);
4035
4036
4037 trace_create_file("trace", 0644, d_cpu,
4038 (void *) cpu, &tracing_fops);
4039
4040 trace_create_file("trace_pipe_raw", 0444, d_cpu,
4041 (void *) cpu, &tracing_buffers_fops);
4042
4043 trace_create_file("stats", 0444, d_cpu,
4044 (void *) cpu, &tracing_stats_fops);
4045}
4046
4047#ifdef CONFIG_FTRACE_SELFTEST
4048
4049#include "trace_selftest.c"
4050#endif
4051
4052struct trace_option_dentry {
4053 struct tracer_opt *opt;
4054 struct tracer_flags *flags;
4055 struct dentry *entry;
4056};
4057
4058static ssize_t
4059trace_options_read(struct file *filp, char __user *ubuf, size_t cnt,
4060 loff_t *ppos)
4061{
4062 struct trace_option_dentry *topt = filp->private_data;
4063 char *buf;
4064
4065 if (topt->flags->val & topt->opt->bit)
4066 buf = "1\n";
4067 else
4068 buf = "0\n";
4069
4070 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
4071}
4072
4073static ssize_t
4074trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
4075 loff_t *ppos)
4076{
4077 struct trace_option_dentry *topt = filp->private_data;
4078 unsigned long val;
4079 char buf[64];
4080 int ret;
4081
4082 if (cnt >= sizeof(buf))
4083 return -EINVAL;
4084
4085 if (copy_from_user(&buf, ubuf, cnt))
4086 return -EFAULT;
4087
4088 buf[cnt] = 0;
4089
4090 ret = strict_strtoul(buf, 10, &val);
4091 if (ret < 0)
4092 return ret;
4093
4094 if (val != 0 && val != 1)
4095 return -EINVAL;
4096
4097 if (!!(topt->flags->val & topt->opt->bit) != val) {
4098 mutex_lock(&trace_types_lock);
4099 ret = __set_tracer_option(current_trace, topt->flags,
4100 topt->opt, !val);
4101 mutex_unlock(&trace_types_lock);
4102 if (ret)
4103 return ret;
4104 }
4105
4106 *ppos += cnt;
4107
4108 return cnt;
4109}
4110
4111
4112static const struct file_operations trace_options_fops = {
4113 .open = tracing_open_generic,
4114 .read = trace_options_read,
4115 .write = trace_options_write,
4116 .llseek = generic_file_llseek,
4117};
4118
4119static ssize_t
4120trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt,
4121 loff_t *ppos)
4122{
4123 long index = (long)filp->private_data;
4124 char *buf;
4125
4126 if (trace_flags & (1 << index))
4127 buf = "1\n";
4128 else
4129 buf = "0\n";
4130
4131 return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
4132}
4133
4134static ssize_t
4135trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
4136 loff_t *ppos)
4137{
4138 long index = (long)filp->private_data;
4139 char buf[64];
4140 unsigned long val;
4141 int ret;
4142
4143 if (cnt >= sizeof(buf))
4144 return -EINVAL;
4145
4146 if (copy_from_user(&buf, ubuf, cnt))
4147 return -EFAULT;
4148
4149 buf[cnt] = 0;
4150
4151 ret = strict_strtoul(buf, 10, &val);
4152 if (ret < 0)
4153 return ret;
4154
4155 if (val != 0 && val != 1)
4156 return -EINVAL;
4157 set_tracer_flags(1 << index, val);
4158
4159 *ppos += cnt;
4160
4161 return cnt;
4162}
4163
4164static const struct file_operations trace_options_core_fops = {
4165 .open = tracing_open_generic,
4166 .read = trace_options_core_read,
4167 .write = trace_options_core_write,
4168 .llseek = generic_file_llseek,
4169};
4170
4171struct dentry *trace_create_file(const char *name,
4172 mode_t mode,
4173 struct dentry *parent,
4174 void *data,
4175 const struct file_operations *fops)
4176{
4177 struct dentry *ret;
4178
4179 ret = debugfs_create_file(name, mode, parent, data, fops);
4180 if (!ret)
4181 pr_warning("Could not create debugfs '%s' entry\n", name);
4182
4183 return ret;
4184}
4185
4186
4187static struct dentry *trace_options_init_dentry(void)
4188{
4189 struct dentry *d_tracer;
4190 static struct dentry *t_options;
4191
4192 if (t_options)
4193 return t_options;
4194
4195 d_tracer = tracing_init_dentry();
4196 if (!d_tracer)
4197 return NULL;
4198
4199 t_options = debugfs_create_dir("options", d_tracer);
4200 if (!t_options) {
4201 pr_warning("Could not create debugfs directory 'options'\n");
4202 return NULL;
4203 }
4204
4205 return t_options;
4206}
4207
4208static void
4209create_trace_option_file(struct trace_option_dentry *topt,
4210 struct tracer_flags *flags,
4211 struct tracer_opt *opt)
4212{
4213 struct dentry *t_options;
4214
4215 t_options = trace_options_init_dentry();
4216 if (!t_options)
4217 return;
4218
4219 topt->flags = flags;
4220 topt->opt = opt;
4221
4222 topt->entry = trace_create_file(opt->name, 0644, t_options, topt,
4223 &trace_options_fops);
4224
4225}
4226
4227static struct trace_option_dentry *
4228create_trace_option_files(struct tracer *tracer)
4229{
4230 struct trace_option_dentry *topts;
4231 struct tracer_flags *flags;
4232 struct tracer_opt *opts;
4233 int cnt;
4234
4235 if (!tracer)
4236 return NULL;
4237
4238 flags = tracer->flags;
4239
4240 if (!flags || !flags->opts)
4241 return NULL;
4242
4243 opts = flags->opts;
4244
4245 for (cnt = 0; opts[cnt].name; cnt++)
4246 ;
4247
4248 topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL);
4249 if (!topts)
4250 return NULL;
4251
4252 for (cnt = 0; opts[cnt].name; cnt++)
4253 create_trace_option_file(&topts[cnt], flags,
4254 &opts[cnt]);
4255
4256 return topts;
4257}
4258
4259static void
4260destroy_trace_option_files(struct trace_option_dentry *topts)
4261{
4262 int cnt;
4263
4264 if (!topts)
4265 return;
4266
4267 for (cnt = 0; topts[cnt].opt; cnt++) {
4268 if (topts[cnt].entry)
4269 debugfs_remove(topts[cnt].entry);
4270 }
4271
4272 kfree(topts);
4273}
4274
4275static struct dentry *
4276create_trace_option_core_file(const char *option, long index)
4277{
4278 struct dentry *t_options;
4279
4280 t_options = trace_options_init_dentry();
4281 if (!t_options)
4282 return NULL;
4283
4284 return trace_create_file(option, 0644, t_options, (void *)index,
4285 &trace_options_core_fops);
4286}
4287
4288static __init void create_trace_options_dir(void)
4289{
4290 struct dentry *t_options;
4291 int i;
4292
4293 t_options = trace_options_init_dentry();
4294 if (!t_options)
4295 return;
4296
4297 for (i = 0; trace_options[i]; i++)
4298 create_trace_option_core_file(trace_options[i], i);
4299}
4300
4301static __init int tracer_init_debugfs(void)
4302{
4303 struct dentry *d_tracer;
4304 int cpu;
4305
4306 trace_access_lock_init();
4307
4308 d_tracer = tracing_init_dentry();
4309
4310 trace_create_file("tracing_enabled", 0644, d_tracer,
4311 &global_trace, &tracing_ctrl_fops);
4312
4313 trace_create_file("trace_options", 0644, d_tracer,
4314 NULL, &tracing_iter_fops);
4315
4316 trace_create_file("tracing_cpumask", 0644, d_tracer,
4317 NULL, &tracing_cpumask_fops);
4318
4319 trace_create_file("trace", 0644, d_tracer,
4320 (void *) TRACE_PIPE_ALL_CPU, &tracing_fops);
4321
4322 trace_create_file("available_tracers", 0444, d_tracer,
4323 &global_trace, &show_traces_fops);
4324
4325 trace_create_file("current_tracer", 0644, d_tracer,
4326 &global_trace, &set_tracer_fops);
4327
4328#ifdef CONFIG_TRACER_MAX_TRACE
4329 trace_create_file("tracing_max_latency", 0644, d_tracer,
4330 &tracing_max_latency, &tracing_max_lat_fops);
4331#endif
4332
4333 trace_create_file("tracing_thresh", 0644, d_tracer,
4334 &tracing_thresh, &tracing_max_lat_fops);
4335
4336 trace_create_file("README", 0444, d_tracer,
4337 NULL, &tracing_readme_fops);
4338
4339 trace_create_file("trace_pipe", 0444, d_tracer,
4340 (void *) TRACE_PIPE_ALL_CPU, &tracing_pipe_fops);
4341
4342 trace_create_file("buffer_size_kb", 0644, d_tracer,
4343 &global_trace, &tracing_entries_fops);
4344
4345 trace_create_file("trace_marker", 0220, d_tracer,
4346 NULL, &tracing_mark_fops);
4347
4348 trace_create_file("saved_cmdlines", 0444, d_tracer,
4349 NULL, &tracing_saved_cmdlines_fops);
4350
4351 trace_create_file("trace_clock", 0644, d_tracer, NULL,
4352 &trace_clock_fops);
4353
4354#ifdef CONFIG_DYNAMIC_FTRACE
4355 trace_create_file("dyn_ftrace_total_info", 0444, d_tracer,
4356 &ftrace_update_tot_cnt, &tracing_dyn_info_fops);
4357#endif
4358
4359 create_trace_options_dir();
4360
4361 for_each_tracing_cpu(cpu)
4362 tracing_init_debugfs_percpu(cpu);
4363
4364 return 0;
4365}
4366
4367static int trace_panic_handler(struct notifier_block *this,
4368 unsigned long event, void *unused)
4369{
4370 if (ftrace_dump_on_oops)
4371 ftrace_dump(ftrace_dump_on_oops);
4372 return NOTIFY_OK;
4373}
4374
4375static struct notifier_block trace_panic_notifier = {
4376 .notifier_call = trace_panic_handler,
4377 .next = NULL,
4378 .priority = 150
4379};
4380
4381static int trace_die_handler(struct notifier_block *self,
4382 unsigned long val,
4383 void *data)
4384{
4385 switch (val) {
4386 case DIE_OOPS:
4387 if (ftrace_dump_on_oops)
4388 ftrace_dump(ftrace_dump_on_oops);
4389 break;
4390 default:
4391 break;
4392 }
4393 return NOTIFY_OK;
4394}
4395
4396static struct notifier_block trace_die_notifier = {
4397 .notifier_call = trace_die_handler,
4398 .priority = 200
4399};
4400
4401
4402
4403
4404
4405#define TRACE_MAX_PRINT 1000
4406
4407
4408
4409
4410
4411
4412#define KERN_TRACE KERN_EMERG
4413
4414void
4415trace_printk_seq(struct trace_seq *s)
4416{
4417
4418 if (s->len >= 1000)
4419 s->len = 1000;
4420
4421
4422 s->buffer[s->len] = 0;
4423
4424 printk(KERN_TRACE "%s", s->buffer);
4425
4426 trace_seq_init(s);
4427}
4428
4429void trace_init_global_iter(struct trace_iterator *iter)
4430{
4431 iter->tr = &global_trace;
4432 iter->trace = current_trace;
4433 iter->cpu_file = TRACE_PIPE_ALL_CPU;
4434}
4435
4436static void
4437__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
4438{
4439 static arch_spinlock_t ftrace_dump_lock =
4440 (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
4441
4442 static struct trace_iterator iter;
4443 unsigned int old_userobj;
4444 static int dump_ran;
4445 unsigned long flags;
4446 int cnt = 0, cpu;
4447
4448
4449 local_irq_save(flags);
4450 arch_spin_lock(&ftrace_dump_lock);
4451 if (dump_ran)
4452 goto out;
4453
4454 dump_ran = 1;
4455
4456 tracing_off();
4457
4458 if (disable_tracing)
4459 ftrace_kill();
4460
4461 trace_init_global_iter(&iter);
4462
4463 for_each_tracing_cpu(cpu) {
4464 atomic_inc(&iter.tr->data[cpu]->disabled);
4465 }
4466
4467 old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ;
4468
4469
4470 trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
4471
4472
4473 iter.tr = &global_trace;
4474 iter.trace = current_trace;
4475
4476 switch (oops_dump_mode) {
4477 case DUMP_ALL:
4478 iter.cpu_file = TRACE_PIPE_ALL_CPU;
4479 break;
4480 case DUMP_ORIG:
4481 iter.cpu_file = raw_smp_processor_id();
4482 break;
4483 case DUMP_NONE:
4484 goto out_enable;
4485 default:
4486 printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
4487 iter.cpu_file = TRACE_PIPE_ALL_CPU;
4488 }
4489
4490 printk(KERN_TRACE "Dumping ftrace buffer:\n");
4491
4492
4493
4494
4495
4496
4497
4498
4499 while (!trace_empty(&iter)) {
4500
4501 if (!cnt)
4502 printk(KERN_TRACE "---------------------------------\n");
4503
4504 cnt++;
4505
4506
4507 memset(&iter.seq, 0,
4508 sizeof(struct trace_iterator) -
4509 offsetof(struct trace_iterator, seq));
4510 iter.iter_flags |= TRACE_FILE_LAT_FMT;
4511 iter.pos = -1;
4512
4513 if (trace_find_next_entry_inc(&iter) != NULL) {
4514 int ret;
4515
4516 ret = print_trace_line(&iter);
4517 if (ret != TRACE_TYPE_NO_CONSUME)
4518 trace_consume(&iter);
4519 }
4520
4521 trace_printk_seq(&iter.seq);
4522 }
4523
4524 if (!cnt)
4525 printk(KERN_TRACE " (ftrace buffer empty)\n");
4526 else
4527 printk(KERN_TRACE "---------------------------------\n");
4528
4529 out_enable:
4530
4531 if (!disable_tracing) {
4532 trace_flags |= old_userobj;
4533
4534 for_each_tracing_cpu(cpu) {
4535 atomic_dec(&iter.tr->data[cpu]->disabled);
4536 }
4537 tracing_on();
4538 }
4539
4540 out:
4541 arch_spin_unlock(&ftrace_dump_lock);
4542 local_irq_restore(flags);
4543}
4544
4545
4546void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
4547{
4548 __ftrace_dump(true, oops_dump_mode);
4549}
4550
4551__init static int tracer_alloc_buffers(void)
4552{
4553 int ring_buf_size;
4554 int i;
4555 int ret = -ENOMEM;
4556
4557 if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
4558 goto out;
4559
4560 if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL))
4561 goto out_free_buffer_mask;
4562
4563
4564 if (ring_buffer_expanded)
4565 ring_buf_size = trace_buf_size;
4566 else
4567 ring_buf_size = 1;
4568
4569 cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
4570 cpumask_copy(tracing_cpumask, cpu_all_mask);
4571
4572
4573 global_trace.buffer = ring_buffer_alloc(ring_buf_size,
4574 TRACE_BUFFER_FLAGS);
4575 if (!global_trace.buffer) {
4576 printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
4577 WARN_ON(1);
4578 goto out_free_cpumask;
4579 }
4580 global_trace.entries = ring_buffer_size(global_trace.buffer);
4581
4582
4583#ifdef CONFIG_TRACER_MAX_TRACE
4584 max_tr.buffer = ring_buffer_alloc(1, TRACE_BUFFER_FLAGS);
4585 if (!max_tr.buffer) {
4586 printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
4587 WARN_ON(1);
4588 ring_buffer_free(global_trace.buffer);
4589 goto out_free_cpumask;
4590 }
4591 max_tr.entries = 1;
4592#endif
4593
4594
4595 for_each_tracing_cpu(i) {
4596 global_trace.data[i] = &per_cpu(global_trace_cpu, i);
4597 max_tr.data[i] = &per_cpu(max_tr_data, i);
4598 }
4599
4600 trace_init_cmdlines();
4601
4602 register_tracer(&nop_trace);
4603 current_trace = &nop_trace;
4604
4605 tracing_disabled = 0;
4606
4607 atomic_notifier_chain_register(&panic_notifier_list,
4608 &trace_panic_notifier);
4609
4610 register_die_notifier(&trace_die_notifier);
4611
4612 return 0;
4613
4614out_free_cpumask:
4615 free_cpumask_var(tracing_cpumask);
4616out_free_buffer_mask:
4617 free_cpumask_var(tracing_buffer_mask);
4618out:
4619 return ret;
4620}
4621
4622__init static int clear_boot_tracer(void)
4623{
4624
4625
4626
4627
4628
4629
4630
4631 if (!default_bootup_tracer)
4632 return 0;
4633
4634 printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n",
4635 default_bootup_tracer);
4636 default_bootup_tracer = NULL;
4637
4638 return 0;
4639}
4640
4641early_initcall(tracer_alloc_buffers);
4642fs_initcall(tracer_init_debugfs);
4643late_initcall(clear_boot_tracer);
4644