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16#include <linux/stop_machine.h>
17#include <linux/clocksource.h>
18#include <linux/kallsyms.h>
19#include <linux/seq_file.h>
20#include <linux/suspend.h>
21#include <linux/debugfs.h>
22#include <linux/hardirq.h>
23#include <linux/kthread.h>
24#include <linux/uaccess.h>
25#include <linux/bsearch.h>
26#include <linux/module.h>
27#include <linux/ftrace.h>
28#include <linux/sysctl.h>
29#include <linux/slab.h>
30#include <linux/ctype.h>
31#include <linux/sort.h>
32#include <linux/list.h>
33#include <linux/hash.h>
34#include <linux/rcupdate.h>
35
36#include <trace/events/sched.h>
37
38#include <asm/setup.h>
39
40#include "trace_output.h"
41#include "trace_stat.h"
42
43#define FTRACE_WARN_ON(cond) \
44 ({ \
45 int ___r = cond; \
46 if (WARN_ON(___r)) \
47 ftrace_kill(); \
48 ___r; \
49 })
50
51#define FTRACE_WARN_ON_ONCE(cond) \
52 ({ \
53 int ___r = cond; \
54 if (WARN_ON_ONCE(___r)) \
55 ftrace_kill(); \
56 ___r; \
57 })
58
59
60#define FTRACE_HASH_BITS 7
61#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
62#define FTRACE_HASH_DEFAULT_BITS 10
63#define FTRACE_HASH_MAX_BITS 12
64
65#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
66
67#ifdef CONFIG_DYNAMIC_FTRACE
68#define INIT_REGEX_LOCK(opsname) \
69 .regex_lock = __MUTEX_INITIALIZER(opsname.regex_lock),
70#else
71#define INIT_REGEX_LOCK(opsname)
72#endif
73
74static struct ftrace_ops ftrace_list_end __read_mostly = {
75 .func = ftrace_stub,
76 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
77};
78
79
80int ftrace_enabled __read_mostly;
81static int last_ftrace_enabled;
82
83
84int function_trace_stop __read_mostly;
85
86
87struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
88
89
90LIST_HEAD(ftrace_pids);
91struct ftrace_pid {
92 struct list_head list;
93 struct pid *pid;
94};
95
96
97
98
99
100static int ftrace_disabled __read_mostly;
101
102static DEFINE_MUTEX(ftrace_lock);
103
104static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
105static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
106static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
107ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
108ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
109static struct ftrace_ops global_ops;
110static struct ftrace_ops control_ops;
111
112#if ARCH_SUPPORTS_FTRACE_OPS
113static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
114 struct ftrace_ops *op, struct pt_regs *regs);
115#else
116
117static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
118#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
119#endif
120
121
122
123
124
125
126
127
128
129
130#define do_for_each_ftrace_op(op, list) \
131 op = rcu_dereference_raw_notrace(list); \
132 do
133
134
135
136
137#define while_for_each_ftrace_op(op) \
138 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
139 unlikely((op) != &ftrace_list_end))
140
141static inline void ftrace_ops_init(struct ftrace_ops *ops)
142{
143#ifdef CONFIG_DYNAMIC_FTRACE
144 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
145 mutex_init(&ops->regex_lock);
146 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
147 }
148#endif
149}
150
151
152
153
154
155
156int ftrace_nr_registered_ops(void)
157{
158 struct ftrace_ops *ops;
159 int cnt = 0;
160
161 mutex_lock(&ftrace_lock);
162
163 for (ops = ftrace_ops_list;
164 ops != &ftrace_list_end; ops = ops->next)
165 cnt++;
166
167 mutex_unlock(&ftrace_lock);
168
169 return cnt;
170}
171
172static void
173ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
174 struct ftrace_ops *op, struct pt_regs *regs)
175{
176 int bit;
177
178 bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX);
179 if (bit < 0)
180 return;
181
182 do_for_each_ftrace_op(op, ftrace_global_list) {
183 op->func(ip, parent_ip, op, regs);
184 } while_for_each_ftrace_op(op);
185
186 trace_clear_recursion(bit);
187}
188
189static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
190 struct ftrace_ops *op, struct pt_regs *regs)
191{
192 if (!test_tsk_trace_trace(current))
193 return;
194
195 ftrace_pid_function(ip, parent_ip, op, regs);
196}
197
198static void set_ftrace_pid_function(ftrace_func_t func)
199{
200
201 if (func != ftrace_pid_func)
202 ftrace_pid_function = func;
203}
204
205
206
207
208
209
210
211void clear_ftrace_function(void)
212{
213 ftrace_trace_function = ftrace_stub;
214 ftrace_pid_function = ftrace_stub;
215}
216
217static void control_ops_disable_all(struct ftrace_ops *ops)
218{
219 int cpu;
220
221 for_each_possible_cpu(cpu)
222 *per_cpu_ptr(ops->disabled, cpu) = 1;
223}
224
225static int control_ops_alloc(struct ftrace_ops *ops)
226{
227 int __percpu *disabled;
228
229 disabled = alloc_percpu(int);
230 if (!disabled)
231 return -ENOMEM;
232
233 ops->disabled = disabled;
234 control_ops_disable_all(ops);
235 return 0;
236}
237
238static void control_ops_free(struct ftrace_ops *ops)
239{
240 free_percpu(ops->disabled);
241}
242
243static void update_global_ops(void)
244{
245 ftrace_func_t func;
246
247
248
249
250
251
252 if (ftrace_global_list == &ftrace_list_end ||
253 ftrace_global_list->next == &ftrace_list_end) {
254 func = ftrace_global_list->func;
255
256
257
258
259
260
261 if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE)
262 global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
263 else
264 global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE;
265 } else {
266 func = ftrace_global_list_func;
267
268 global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
269 }
270
271
272
273 if (!list_empty(&ftrace_pids)) {
274 set_ftrace_pid_function(func);
275 func = ftrace_pid_func;
276 }
277
278 global_ops.func = func;
279}
280
281static void update_ftrace_function(void)
282{
283 ftrace_func_t func;
284
285 update_global_ops();
286
287
288
289
290
291
292 if (ftrace_ops_list == &ftrace_list_end ||
293 (ftrace_ops_list->next == &ftrace_list_end &&
294 !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) &&
295 (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) &&
296 !FTRACE_FORCE_LIST_FUNC)) {
297
298 if (ftrace_ops_list == &global_ops)
299 function_trace_op = ftrace_global_list;
300 else
301 function_trace_op = ftrace_ops_list;
302 func = ftrace_ops_list->func;
303 } else {
304
305 function_trace_op = &ftrace_list_end;
306 func = ftrace_ops_list_func;
307 }
308
309 ftrace_trace_function = func;
310}
311
312static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
313{
314 ops->next = *list;
315
316
317
318
319
320
321 rcu_assign_pointer(*list, ops);
322}
323
324static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
325{
326 struct ftrace_ops **p;
327
328
329
330
331
332 if (*list == ops && ops->next == &ftrace_list_end) {
333 *list = &ftrace_list_end;
334 return 0;
335 }
336
337 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
338 if (*p == ops)
339 break;
340
341 if (*p != ops)
342 return -1;
343
344 *p = (*p)->next;
345 return 0;
346}
347
348static void add_ftrace_list_ops(struct ftrace_ops **list,
349 struct ftrace_ops *main_ops,
350 struct ftrace_ops *ops)
351{
352 int first = *list == &ftrace_list_end;
353 add_ftrace_ops(list, ops);
354 if (first)
355 add_ftrace_ops(&ftrace_ops_list, main_ops);
356}
357
358static int remove_ftrace_list_ops(struct ftrace_ops **list,
359 struct ftrace_ops *main_ops,
360 struct ftrace_ops *ops)
361{
362 int ret = remove_ftrace_ops(list, ops);
363 if (!ret && *list == &ftrace_list_end)
364 ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
365 return ret;
366}
367
368static int __register_ftrace_function(struct ftrace_ops *ops)
369{
370 if (unlikely(ftrace_disabled))
371 return -ENODEV;
372
373 if (FTRACE_WARN_ON(ops == &global_ops))
374 return -EINVAL;
375
376 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
377 return -EBUSY;
378
379
380 if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
381 return -EINVAL;
382
383#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
384
385
386
387
388
389 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
390 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
391 return -EINVAL;
392
393 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
394 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
395#endif
396
397 if (!core_kernel_data((unsigned long)ops))
398 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
399
400 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
401 add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops);
402 ops->flags |= FTRACE_OPS_FL_ENABLED;
403 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
404 if (control_ops_alloc(ops))
405 return -ENOMEM;
406 add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
407 } else
408 add_ftrace_ops(&ftrace_ops_list, ops);
409
410 if (ftrace_enabled)
411 update_ftrace_function();
412
413 return 0;
414}
415
416static void ftrace_sync(struct work_struct *work)
417{
418
419
420
421
422
423
424
425}
426
427static int __unregister_ftrace_function(struct ftrace_ops *ops)
428{
429 int ret;
430
431 if (ftrace_disabled)
432 return -ENODEV;
433
434 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
435 return -EBUSY;
436
437 if (FTRACE_WARN_ON(ops == &global_ops))
438 return -EINVAL;
439
440 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
441 ret = remove_ftrace_list_ops(&ftrace_global_list,
442 &global_ops, ops);
443 if (!ret)
444 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
445 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
446 ret = remove_ftrace_list_ops(&ftrace_control_list,
447 &control_ops, ops);
448 if (!ret) {
449
450
451
452
453
454
455
456
457
458
459 schedule_on_each_cpu(ftrace_sync);
460 control_ops_free(ops);
461 }
462 } else
463 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
464
465 if (ret < 0)
466 return ret;
467
468 if (ftrace_enabled)
469 update_ftrace_function();
470
471
472
473
474
475
476
477
478 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
479 schedule_on_each_cpu(ftrace_sync);
480
481
482 return 0;
483}
484
485static void ftrace_update_pid_func(void)
486{
487
488 if (ftrace_trace_function == ftrace_stub)
489 return;
490
491 update_ftrace_function();
492}
493
494#ifdef CONFIG_FUNCTION_PROFILER
495struct ftrace_profile {
496 struct hlist_node node;
497 unsigned long ip;
498 unsigned long counter;
499#ifdef CONFIG_FUNCTION_GRAPH_TRACER
500 unsigned long long time;
501 unsigned long long time_squared;
502#endif
503};
504
505struct ftrace_profile_page {
506 struct ftrace_profile_page *next;
507 unsigned long index;
508 struct ftrace_profile records[];
509};
510
511struct ftrace_profile_stat {
512 atomic_t disabled;
513 struct hlist_head *hash;
514 struct ftrace_profile_page *pages;
515 struct ftrace_profile_page *start;
516 struct tracer_stat stat;
517};
518
519#define PROFILE_RECORDS_SIZE \
520 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
521
522#define PROFILES_PER_PAGE \
523 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
524
525static int ftrace_profile_enabled __read_mostly;
526
527
528static DEFINE_MUTEX(ftrace_profile_lock);
529
530static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
531
532#define FTRACE_PROFILE_HASH_BITS 10
533#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
534
535static void *
536function_stat_next(void *v, int idx)
537{
538 struct ftrace_profile *rec = v;
539 struct ftrace_profile_page *pg;
540
541 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
542
543 again:
544 if (idx != 0)
545 rec++;
546
547 if ((void *)rec >= (void *)&pg->records[pg->index]) {
548 pg = pg->next;
549 if (!pg)
550 return NULL;
551 rec = &pg->records[0];
552 if (!rec->counter)
553 goto again;
554 }
555
556 return rec;
557}
558
559static void *function_stat_start(struct tracer_stat *trace)
560{
561 struct ftrace_profile_stat *stat =
562 container_of(trace, struct ftrace_profile_stat, stat);
563
564 if (!stat || !stat->start)
565 return NULL;
566
567 return function_stat_next(&stat->start->records[0], 0);
568}
569
570#ifdef CONFIG_FUNCTION_GRAPH_TRACER
571
572static int function_stat_cmp(void *p1, void *p2)
573{
574 struct ftrace_profile *a = p1;
575 struct ftrace_profile *b = p2;
576
577 if (a->time < b->time)
578 return -1;
579 if (a->time > b->time)
580 return 1;
581 else
582 return 0;
583}
584#else
585
586static int function_stat_cmp(void *p1, void *p2)
587{
588 struct ftrace_profile *a = p1;
589 struct ftrace_profile *b = p2;
590
591 if (a->counter < b->counter)
592 return -1;
593 if (a->counter > b->counter)
594 return 1;
595 else
596 return 0;
597}
598#endif
599
600static int function_stat_headers(struct seq_file *m)
601{
602#ifdef CONFIG_FUNCTION_GRAPH_TRACER
603 seq_printf(m, " Function "
604 "Hit Time Avg s^2\n"
605 " -------- "
606 "--- ---- --- ---\n");
607#else
608 seq_printf(m, " Function Hit\n"
609 " -------- ---\n");
610#endif
611 return 0;
612}
613
614static int function_stat_show(struct seq_file *m, void *v)
615{
616 struct ftrace_profile *rec = v;
617 char str[KSYM_SYMBOL_LEN];
618 int ret = 0;
619#ifdef CONFIG_FUNCTION_GRAPH_TRACER
620 static struct trace_seq s;
621 unsigned long long avg;
622 unsigned long long stddev;
623#endif
624 mutex_lock(&ftrace_profile_lock);
625
626
627 if (unlikely(rec->counter == 0)) {
628 ret = -EBUSY;
629 goto out;
630 }
631
632 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
633 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
634
635#ifdef CONFIG_FUNCTION_GRAPH_TRACER
636 seq_printf(m, " ");
637 avg = rec->time;
638 do_div(avg, rec->counter);
639
640
641 if (rec->counter <= 1)
642 stddev = 0;
643 else {
644
645
646
647
648 stddev = rec->counter * rec->time_squared -
649 rec->time * rec->time;
650
651
652
653
654
655 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
656 }
657
658 trace_seq_init(&s);
659 trace_print_graph_duration(rec->time, &s);
660 trace_seq_puts(&s, " ");
661 trace_print_graph_duration(avg, &s);
662 trace_seq_puts(&s, " ");
663 trace_print_graph_duration(stddev, &s);
664 trace_print_seq(m, &s);
665#endif
666 seq_putc(m, '\n');
667out:
668 mutex_unlock(&ftrace_profile_lock);
669
670 return ret;
671}
672
673static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
674{
675 struct ftrace_profile_page *pg;
676
677 pg = stat->pages = stat->start;
678
679 while (pg) {
680 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
681 pg->index = 0;
682 pg = pg->next;
683 }
684
685 memset(stat->hash, 0,
686 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
687}
688
689int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
690{
691 struct ftrace_profile_page *pg;
692 int functions;
693 int pages;
694 int i;
695
696
697 if (stat->pages)
698 return 0;
699
700 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
701 if (!stat->pages)
702 return -ENOMEM;
703
704#ifdef CONFIG_DYNAMIC_FTRACE
705 functions = ftrace_update_tot_cnt;
706#else
707
708
709
710
711
712
713
714 functions = 20000;
715#endif
716
717 pg = stat->start = stat->pages;
718
719 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
720
721 for (i = 1; i < pages; i++) {
722 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
723 if (!pg->next)
724 goto out_free;
725 pg = pg->next;
726 }
727
728 return 0;
729
730 out_free:
731 pg = stat->start;
732 while (pg) {
733 unsigned long tmp = (unsigned long)pg;
734
735 pg = pg->next;
736 free_page(tmp);
737 }
738
739 stat->pages = NULL;
740 stat->start = NULL;
741
742 return -ENOMEM;
743}
744
745static int ftrace_profile_init_cpu(int cpu)
746{
747 struct ftrace_profile_stat *stat;
748 int size;
749
750 stat = &per_cpu(ftrace_profile_stats, cpu);
751
752 if (stat->hash) {
753
754 ftrace_profile_reset(stat);
755 return 0;
756 }
757
758
759
760
761
762 size = FTRACE_PROFILE_HASH_SIZE;
763
764 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
765
766 if (!stat->hash)
767 return -ENOMEM;
768
769
770 if (ftrace_profile_pages_init(stat) < 0) {
771 kfree(stat->hash);
772 stat->hash = NULL;
773 return -ENOMEM;
774 }
775
776 return 0;
777}
778
779static int ftrace_profile_init(void)
780{
781 int cpu;
782 int ret = 0;
783
784 for_each_online_cpu(cpu) {
785 ret = ftrace_profile_init_cpu(cpu);
786 if (ret)
787 break;
788 }
789
790 return ret;
791}
792
793
794static struct ftrace_profile *
795ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
796{
797 struct ftrace_profile *rec;
798 struct hlist_head *hhd;
799 unsigned long key;
800
801 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
802 hhd = &stat->hash[key];
803
804 if (hlist_empty(hhd))
805 return NULL;
806
807 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
808 if (rec->ip == ip)
809 return rec;
810 }
811
812 return NULL;
813}
814
815static void ftrace_add_profile(struct ftrace_profile_stat *stat,
816 struct ftrace_profile *rec)
817{
818 unsigned long key;
819
820 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
821 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
822}
823
824
825
826
827static struct ftrace_profile *
828ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
829{
830 struct ftrace_profile *rec = NULL;
831
832
833 if (atomic_inc_return(&stat->disabled) != 1)
834 goto out;
835
836
837
838
839
840 rec = ftrace_find_profiled_func(stat, ip);
841 if (rec)
842 goto out;
843
844 if (stat->pages->index == PROFILES_PER_PAGE) {
845 if (!stat->pages->next)
846 goto out;
847 stat->pages = stat->pages->next;
848 }
849
850 rec = &stat->pages->records[stat->pages->index++];
851 rec->ip = ip;
852 ftrace_add_profile(stat, rec);
853
854 out:
855 atomic_dec(&stat->disabled);
856
857 return rec;
858}
859
860static void
861function_profile_call(unsigned long ip, unsigned long parent_ip,
862 struct ftrace_ops *ops, struct pt_regs *regs)
863{
864 struct ftrace_profile_stat *stat;
865 struct ftrace_profile *rec;
866 unsigned long flags;
867
868 if (!ftrace_profile_enabled)
869 return;
870
871 local_irq_save(flags);
872
873 stat = &__get_cpu_var(ftrace_profile_stats);
874 if (!stat->hash || !ftrace_profile_enabled)
875 goto out;
876
877 rec = ftrace_find_profiled_func(stat, ip);
878 if (!rec) {
879 rec = ftrace_profile_alloc(stat, ip);
880 if (!rec)
881 goto out;
882 }
883
884 rec->counter++;
885 out:
886 local_irq_restore(flags);
887}
888
889#ifdef CONFIG_FUNCTION_GRAPH_TRACER
890static int profile_graph_entry(struct ftrace_graph_ent *trace)
891{
892 function_profile_call(trace->func, 0, NULL, NULL);
893 return 1;
894}
895
896static void profile_graph_return(struct ftrace_graph_ret *trace)
897{
898 struct ftrace_profile_stat *stat;
899 unsigned long long calltime;
900 struct ftrace_profile *rec;
901 unsigned long flags;
902
903 local_irq_save(flags);
904 stat = &__get_cpu_var(ftrace_profile_stats);
905 if (!stat->hash || !ftrace_profile_enabled)
906 goto out;
907
908
909 if (!trace->calltime)
910 goto out;
911
912 calltime = trace->rettime - trace->calltime;
913
914 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
915 int index;
916
917 index = trace->depth;
918
919
920 if (index)
921 current->ret_stack[index - 1].subtime += calltime;
922
923 if (current->ret_stack[index].subtime < calltime)
924 calltime -= current->ret_stack[index].subtime;
925 else
926 calltime = 0;
927 }
928
929 rec = ftrace_find_profiled_func(stat, trace->func);
930 if (rec) {
931 rec->time += calltime;
932 rec->time_squared += calltime * calltime;
933 }
934
935 out:
936 local_irq_restore(flags);
937}
938
939static int register_ftrace_profiler(void)
940{
941 return register_ftrace_graph(&profile_graph_return,
942 &profile_graph_entry);
943}
944
945static void unregister_ftrace_profiler(void)
946{
947 unregister_ftrace_graph();
948}
949#else
950static struct ftrace_ops ftrace_profile_ops __read_mostly = {
951 .func = function_profile_call,
952 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
953 INIT_REGEX_LOCK(ftrace_profile_ops)
954};
955
956static int register_ftrace_profiler(void)
957{
958 return register_ftrace_function(&ftrace_profile_ops);
959}
960
961static void unregister_ftrace_profiler(void)
962{
963 unregister_ftrace_function(&ftrace_profile_ops);
964}
965#endif
966
967static ssize_t
968ftrace_profile_write(struct file *filp, const char __user *ubuf,
969 size_t cnt, loff_t *ppos)
970{
971 unsigned long val;
972 int ret;
973
974 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
975 if (ret)
976 return ret;
977
978 val = !!val;
979
980 mutex_lock(&ftrace_profile_lock);
981 if (ftrace_profile_enabled ^ val) {
982 if (val) {
983 ret = ftrace_profile_init();
984 if (ret < 0) {
985 cnt = ret;
986 goto out;
987 }
988
989 ret = register_ftrace_profiler();
990 if (ret < 0) {
991 cnt = ret;
992 goto out;
993 }
994 ftrace_profile_enabled = 1;
995 } else {
996 ftrace_profile_enabled = 0;
997
998
999
1000
1001 unregister_ftrace_profiler();
1002 }
1003 }
1004 out:
1005 mutex_unlock(&ftrace_profile_lock);
1006
1007 *ppos += cnt;
1008
1009 return cnt;
1010}
1011
1012static ssize_t
1013ftrace_profile_read(struct file *filp, char __user *ubuf,
1014 size_t cnt, loff_t *ppos)
1015{
1016 char buf[64];
1017 int r;
1018
1019 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
1020 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
1021}
1022
1023static const struct file_operations ftrace_profile_fops = {
1024 .open = tracing_open_generic,
1025 .read = ftrace_profile_read,
1026 .write = ftrace_profile_write,
1027 .llseek = default_llseek,
1028};
1029
1030
1031static struct tracer_stat function_stats __initdata = {
1032 .name = "functions",
1033 .stat_start = function_stat_start,
1034 .stat_next = function_stat_next,
1035 .stat_cmp = function_stat_cmp,
1036 .stat_headers = function_stat_headers,
1037 .stat_show = function_stat_show
1038};
1039
1040static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
1041{
1042 struct ftrace_profile_stat *stat;
1043 struct dentry *entry;
1044 char *name;
1045 int ret;
1046 int cpu;
1047
1048 for_each_possible_cpu(cpu) {
1049 stat = &per_cpu(ftrace_profile_stats, cpu);
1050
1051
1052 name = kmalloc(32, GFP_KERNEL);
1053 if (!name) {
1054
1055
1056
1057
1058 WARN(1,
1059 "Could not allocate stat file for cpu %d\n",
1060 cpu);
1061 return;
1062 }
1063 stat->stat = function_stats;
1064 snprintf(name, 32, "function%d", cpu);
1065 stat->stat.name = name;
1066 ret = register_stat_tracer(&stat->stat);
1067 if (ret) {
1068 WARN(1,
1069 "Could not register function stat for cpu %d\n",
1070 cpu);
1071 kfree(name);
1072 return;
1073 }
1074 }
1075
1076 entry = debugfs_create_file("function_profile_enabled", 0644,
1077 d_tracer, NULL, &ftrace_profile_fops);
1078 if (!entry)
1079 pr_warning("Could not create debugfs "
1080 "'function_profile_enabled' entry\n");
1081}
1082
1083#else
1084static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
1085{
1086}
1087#endif
1088
1089static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1090
1091loff_t
1092ftrace_filter_lseek(struct file *file, loff_t offset, int whence)
1093{
1094 loff_t ret;
1095
1096 if (file->f_mode & FMODE_READ)
1097 ret = seq_lseek(file, offset, whence);
1098 else
1099 file->f_pos = ret = 1;
1100
1101 return ret;
1102}
1103
1104#ifdef CONFIG_DYNAMIC_FTRACE
1105
1106#ifndef CONFIG_FTRACE_MCOUNT_RECORD
1107# error Dynamic ftrace depends on MCOUNT_RECORD
1108#endif
1109
1110static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
1111
1112struct ftrace_func_probe {
1113 struct hlist_node node;
1114 struct ftrace_probe_ops *ops;
1115 unsigned long flags;
1116 unsigned long ip;
1117 void *data;
1118 struct list_head free_list;
1119};
1120
1121struct ftrace_func_entry {
1122 struct hlist_node hlist;
1123 unsigned long ip;
1124};
1125
1126struct ftrace_hash {
1127 unsigned long size_bits;
1128 struct hlist_head *buckets;
1129 unsigned long count;
1130 struct rcu_head rcu;
1131};
1132
1133
1134
1135
1136
1137
1138
1139static const struct hlist_head empty_buckets[1];
1140static const struct ftrace_hash empty_hash = {
1141 .buckets = (struct hlist_head *)empty_buckets,
1142};
1143#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1144
1145static struct ftrace_ops global_ops = {
1146 .func = ftrace_stub,
1147 .notrace_hash = EMPTY_HASH,
1148 .filter_hash = EMPTY_HASH,
1149 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
1150 INIT_REGEX_LOCK(global_ops)
1151};
1152
1153struct ftrace_page {
1154 struct ftrace_page *next;
1155 struct dyn_ftrace *records;
1156 int index;
1157 int size;
1158};
1159
1160static struct ftrace_page *ftrace_new_pgs;
1161
1162#define ENTRY_SIZE sizeof(struct dyn_ftrace)
1163#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1164
1165
1166#define NR_TO_INIT 10000
1167
1168static struct ftrace_page *ftrace_pages_start;
1169static struct ftrace_page *ftrace_pages;
1170
1171static bool ftrace_hash_empty(struct ftrace_hash *hash)
1172{
1173 return !hash || !hash->count;
1174}
1175
1176static struct ftrace_func_entry *
1177ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1178{
1179 unsigned long key;
1180 struct ftrace_func_entry *entry;
1181 struct hlist_head *hhd;
1182
1183 if (ftrace_hash_empty(hash))
1184 return NULL;
1185
1186 if (hash->size_bits > 0)
1187 key = hash_long(ip, hash->size_bits);
1188 else
1189 key = 0;
1190
1191 hhd = &hash->buckets[key];
1192
1193 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1194 if (entry->ip == ip)
1195 return entry;
1196 }
1197 return NULL;
1198}
1199
1200static void __add_hash_entry(struct ftrace_hash *hash,
1201 struct ftrace_func_entry *entry)
1202{
1203 struct hlist_head *hhd;
1204 unsigned long key;
1205
1206 if (hash->size_bits)
1207 key = hash_long(entry->ip, hash->size_bits);
1208 else
1209 key = 0;
1210
1211 hhd = &hash->buckets[key];
1212 hlist_add_head(&entry->hlist, hhd);
1213 hash->count++;
1214}
1215
1216static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1217{
1218 struct ftrace_func_entry *entry;
1219
1220 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1221 if (!entry)
1222 return -ENOMEM;
1223
1224 entry->ip = ip;
1225 __add_hash_entry(hash, entry);
1226
1227 return 0;
1228}
1229
1230static void
1231free_hash_entry(struct ftrace_hash *hash,
1232 struct ftrace_func_entry *entry)
1233{
1234 hlist_del(&entry->hlist);
1235 kfree(entry);
1236 hash->count--;
1237}
1238
1239static void
1240remove_hash_entry(struct ftrace_hash *hash,
1241 struct ftrace_func_entry *entry)
1242{
1243 hlist_del(&entry->hlist);
1244 hash->count--;
1245}
1246
1247static void ftrace_hash_clear(struct ftrace_hash *hash)
1248{
1249 struct hlist_head *hhd;
1250 struct hlist_node *tn;
1251 struct ftrace_func_entry *entry;
1252 int size = 1 << hash->size_bits;
1253 int i;
1254
1255 if (!hash->count)
1256 return;
1257
1258 for (i = 0; i < size; i++) {
1259 hhd = &hash->buckets[i];
1260 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1261 free_hash_entry(hash, entry);
1262 }
1263 FTRACE_WARN_ON(hash->count);
1264}
1265
1266static void free_ftrace_hash(struct ftrace_hash *hash)
1267{
1268 if (!hash || hash == EMPTY_HASH)
1269 return;
1270 ftrace_hash_clear(hash);
1271 kfree(hash->buckets);
1272 kfree(hash);
1273}
1274
1275static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1276{
1277 struct ftrace_hash *hash;
1278
1279 hash = container_of(rcu, struct ftrace_hash, rcu);
1280 free_ftrace_hash(hash);
1281}
1282
1283static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1284{
1285 if (!hash || hash == EMPTY_HASH)
1286 return;
1287 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1288}
1289
1290void ftrace_free_filter(struct ftrace_ops *ops)
1291{
1292 ftrace_ops_init(ops);
1293 free_ftrace_hash(ops->filter_hash);
1294 free_ftrace_hash(ops->notrace_hash);
1295}
1296
1297static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1298{
1299 struct ftrace_hash *hash;
1300 int size;
1301
1302 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1303 if (!hash)
1304 return NULL;
1305
1306 size = 1 << size_bits;
1307 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1308
1309 if (!hash->buckets) {
1310 kfree(hash);
1311 return NULL;
1312 }
1313
1314 hash->size_bits = size_bits;
1315
1316 return hash;
1317}
1318
1319static struct ftrace_hash *
1320alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1321{
1322 struct ftrace_func_entry *entry;
1323 struct ftrace_hash *new_hash;
1324 int size;
1325 int ret;
1326 int i;
1327
1328 new_hash = alloc_ftrace_hash(size_bits);
1329 if (!new_hash)
1330 return NULL;
1331
1332
1333 if (ftrace_hash_empty(hash))
1334 return new_hash;
1335
1336 size = 1 << hash->size_bits;
1337 for (i = 0; i < size; i++) {
1338 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1339 ret = add_hash_entry(new_hash, entry->ip);
1340 if (ret < 0)
1341 goto free_hash;
1342 }
1343 }
1344
1345 FTRACE_WARN_ON(new_hash->count != hash->count);
1346
1347 return new_hash;
1348
1349 free_hash:
1350 free_ftrace_hash(new_hash);
1351 return NULL;
1352}
1353
1354static void
1355ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
1356static void
1357ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
1358
1359static int
1360ftrace_hash_move(struct ftrace_ops *ops, int enable,
1361 struct ftrace_hash **dst, struct ftrace_hash *src)
1362{
1363 struct ftrace_func_entry *entry;
1364 struct hlist_node *tn;
1365 struct hlist_head *hhd;
1366 struct ftrace_hash *old_hash;
1367 struct ftrace_hash *new_hash;
1368 int size = src->count;
1369 int bits = 0;
1370 int ret;
1371 int i;
1372
1373
1374
1375
1376
1377 ftrace_hash_rec_disable(ops, enable);
1378
1379
1380
1381
1382
1383 if (!src->count) {
1384 free_ftrace_hash_rcu(*dst);
1385 rcu_assign_pointer(*dst, EMPTY_HASH);
1386
1387 ret = 0;
1388 goto out;
1389 }
1390
1391
1392
1393
1394 for (size /= 2; size; size >>= 1)
1395 bits++;
1396
1397
1398 if (bits > FTRACE_HASH_MAX_BITS)
1399 bits = FTRACE_HASH_MAX_BITS;
1400
1401 ret = -ENOMEM;
1402 new_hash = alloc_ftrace_hash(bits);
1403 if (!new_hash)
1404 goto out;
1405
1406 size = 1 << src->size_bits;
1407 for (i = 0; i < size; i++) {
1408 hhd = &src->buckets[i];
1409 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1410 remove_hash_entry(src, entry);
1411 __add_hash_entry(new_hash, entry);
1412 }
1413 }
1414
1415 old_hash = *dst;
1416 rcu_assign_pointer(*dst, new_hash);
1417 free_ftrace_hash_rcu(old_hash);
1418
1419 ret = 0;
1420 out:
1421
1422
1423
1424
1425
1426 ftrace_hash_rec_enable(ops, enable);
1427
1428 return ret;
1429}
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443static int
1444ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1445{
1446 struct ftrace_hash *filter_hash;
1447 struct ftrace_hash *notrace_hash;
1448 int ret;
1449
1450#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1451
1452
1453
1454
1455
1456 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1457 return 0;
1458#endif
1459
1460 filter_hash = rcu_dereference_raw_notrace(ops->filter_hash);
1461 notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash);
1462
1463 if ((ftrace_hash_empty(filter_hash) ||
1464 ftrace_lookup_ip(filter_hash, ip)) &&
1465 (ftrace_hash_empty(notrace_hash) ||
1466 !ftrace_lookup_ip(notrace_hash, ip)))
1467 ret = 1;
1468 else
1469 ret = 0;
1470
1471 return ret;
1472}
1473
1474
1475
1476
1477
1478#define do_for_each_ftrace_rec(pg, rec) \
1479 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1480 int _____i; \
1481 for (_____i = 0; _____i < pg->index; _____i++) { \
1482 rec = &pg->records[_____i];
1483
1484#define while_for_each_ftrace_rec() \
1485 } \
1486 }
1487
1488
1489static int ftrace_cmp_recs(const void *a, const void *b)
1490{
1491 const struct dyn_ftrace *key = a;
1492 const struct dyn_ftrace *rec = b;
1493
1494 if (key->flags < rec->ip)
1495 return -1;
1496 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1497 return 1;
1498 return 0;
1499}
1500
1501static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1502{
1503 struct ftrace_page *pg;
1504 struct dyn_ftrace *rec;
1505 struct dyn_ftrace key;
1506
1507 key.ip = start;
1508 key.flags = end;
1509
1510 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1511 if (end < pg->records[0].ip ||
1512 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1513 continue;
1514 rec = bsearch(&key, pg->records, pg->index,
1515 sizeof(struct dyn_ftrace),
1516 ftrace_cmp_recs);
1517 if (rec)
1518 return rec->ip;
1519 }
1520
1521 return 0;
1522}
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533unsigned long ftrace_location(unsigned long ip)
1534{
1535 return ftrace_location_range(ip, ip);
1536}
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548int ftrace_text_reserved(void *start, void *end)
1549{
1550 unsigned long ret;
1551
1552 ret = ftrace_location_range((unsigned long)start,
1553 (unsigned long)end);
1554
1555 return (int)!!ret;
1556}
1557
1558static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1559 int filter_hash,
1560 bool inc)
1561{
1562 struct ftrace_hash *hash;
1563 struct ftrace_hash *other_hash;
1564 struct ftrace_page *pg;
1565 struct dyn_ftrace *rec;
1566 int count = 0;
1567 int all = 0;
1568
1569
1570 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1571 return;
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584 if (filter_hash) {
1585 hash = ops->filter_hash;
1586 other_hash = ops->notrace_hash;
1587 if (ftrace_hash_empty(hash))
1588 all = 1;
1589 } else {
1590 inc = !inc;
1591 hash = ops->notrace_hash;
1592 other_hash = ops->filter_hash;
1593
1594
1595
1596
1597 if (ftrace_hash_empty(hash))
1598 return;
1599 }
1600
1601 do_for_each_ftrace_rec(pg, rec) {
1602 int in_other_hash = 0;
1603 int in_hash = 0;
1604 int match = 0;
1605
1606 if (all) {
1607
1608
1609
1610
1611 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1612 match = 1;
1613 } else {
1614 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1615 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1616
1617
1618
1619
1620 if (filter_hash && in_hash && !in_other_hash)
1621 match = 1;
1622 else if (!filter_hash && in_hash &&
1623 (in_other_hash || ftrace_hash_empty(other_hash)))
1624 match = 1;
1625 }
1626 if (!match)
1627 continue;
1628
1629 if (inc) {
1630 rec->flags++;
1631 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
1632 return;
1633
1634
1635
1636
1637 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1638 rec->flags |= FTRACE_FL_REGS;
1639 } else {
1640 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
1641 return;
1642 rec->flags--;
1643 }
1644 count++;
1645
1646 if (!all && count == hash->count)
1647 return;
1648 } while_for_each_ftrace_rec();
1649}
1650
1651static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1652 int filter_hash)
1653{
1654 __ftrace_hash_rec_update(ops, filter_hash, 0);
1655}
1656
1657static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1658 int filter_hash)
1659{
1660 __ftrace_hash_rec_update(ops, filter_hash, 1);
1661}
1662
1663static void print_ip_ins(const char *fmt, unsigned char *p)
1664{
1665 int i;
1666
1667 printk(KERN_CONT "%s", fmt);
1668
1669 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1670 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1671}
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685void ftrace_bug(int failed, unsigned long ip)
1686{
1687 switch (failed) {
1688 case -EFAULT:
1689 FTRACE_WARN_ON_ONCE(1);
1690 pr_info("ftrace faulted on modifying ");
1691 print_ip_sym(ip);
1692 break;
1693 case -EINVAL:
1694 FTRACE_WARN_ON_ONCE(1);
1695 pr_info("ftrace failed to modify ");
1696 print_ip_sym(ip);
1697 print_ip_ins(" actual: ", (unsigned char *)ip);
1698 printk(KERN_CONT "\n");
1699 break;
1700 case -EPERM:
1701 FTRACE_WARN_ON_ONCE(1);
1702 pr_info("ftrace faulted on writing ");
1703 print_ip_sym(ip);
1704 break;
1705 default:
1706 FTRACE_WARN_ON_ONCE(1);
1707 pr_info("ftrace faulted on unknown error ");
1708 print_ip_sym(ip);
1709 }
1710}
1711
1712static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
1713{
1714 unsigned long flag = 0UL;
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727 if (enable && (rec->flags & ~FTRACE_FL_MASK))
1728 flag = FTRACE_FL_ENABLED;
1729
1730
1731
1732
1733
1734
1735 if (flag &&
1736 (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN)))
1737 flag |= FTRACE_FL_REGS;
1738
1739
1740 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
1741 return FTRACE_UPDATE_IGNORE;
1742
1743 if (flag) {
1744
1745 flag ^= rec->flags & FTRACE_FL_ENABLED;
1746
1747 if (update) {
1748 rec->flags |= FTRACE_FL_ENABLED;
1749 if (flag & FTRACE_FL_REGS) {
1750 if (rec->flags & FTRACE_FL_REGS)
1751 rec->flags |= FTRACE_FL_REGS_EN;
1752 else
1753 rec->flags &= ~FTRACE_FL_REGS_EN;
1754 }
1755 }
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767 if (flag & FTRACE_FL_ENABLED)
1768 return FTRACE_UPDATE_MAKE_CALL;
1769 else if (rec->flags & FTRACE_FL_REGS_EN)
1770 return FTRACE_UPDATE_MODIFY_CALL_REGS;
1771 else
1772 return FTRACE_UPDATE_MODIFY_CALL;
1773 }
1774
1775 if (update) {
1776
1777 if (!(rec->flags & ~FTRACE_FL_MASK))
1778 rec->flags = 0;
1779 else
1780
1781 rec->flags &= ~FTRACE_FL_ENABLED;
1782 }
1783
1784 return FTRACE_UPDATE_MAKE_NOP;
1785}
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795int ftrace_update_record(struct dyn_ftrace *rec, int enable)
1796{
1797 return ftrace_check_record(rec, enable, 1);
1798}
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809int ftrace_test_record(struct dyn_ftrace *rec, int enable)
1810{
1811 return ftrace_check_record(rec, enable, 0);
1812}
1813
1814static int
1815__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1816{
1817 unsigned long ftrace_old_addr;
1818 unsigned long ftrace_addr;
1819 int ret;
1820
1821 ret = ftrace_update_record(rec, enable);
1822
1823 if (rec->flags & FTRACE_FL_REGS)
1824 ftrace_addr = (unsigned long)FTRACE_REGS_ADDR;
1825 else
1826 ftrace_addr = (unsigned long)FTRACE_ADDR;
1827
1828 switch (ret) {
1829 case FTRACE_UPDATE_IGNORE:
1830 return 0;
1831
1832 case FTRACE_UPDATE_MAKE_CALL:
1833 return ftrace_make_call(rec, ftrace_addr);
1834
1835 case FTRACE_UPDATE_MAKE_NOP:
1836 return ftrace_make_nop(NULL, rec, ftrace_addr);
1837
1838 case FTRACE_UPDATE_MODIFY_CALL_REGS:
1839 case FTRACE_UPDATE_MODIFY_CALL:
1840 if (rec->flags & FTRACE_FL_REGS)
1841 ftrace_old_addr = (unsigned long)FTRACE_ADDR;
1842 else
1843 ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR;
1844
1845 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
1846 }
1847
1848 return -1;
1849}
1850
1851void __weak ftrace_replace_code(int enable)
1852{
1853 struct dyn_ftrace *rec;
1854 struct ftrace_page *pg;
1855 int failed;
1856
1857 if (unlikely(ftrace_disabled))
1858 return;
1859
1860 do_for_each_ftrace_rec(pg, rec) {
1861 failed = __ftrace_replace_code(rec, enable);
1862 if (failed) {
1863 ftrace_bug(failed, rec->ip);
1864
1865 return;
1866 }
1867 } while_for_each_ftrace_rec();
1868}
1869
1870struct ftrace_rec_iter {
1871 struct ftrace_page *pg;
1872 int index;
1873};
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884struct ftrace_rec_iter *ftrace_rec_iter_start(void)
1885{
1886
1887
1888
1889
1890 static struct ftrace_rec_iter ftrace_rec_iter;
1891 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
1892
1893 iter->pg = ftrace_pages_start;
1894 iter->index = 0;
1895
1896
1897 while (iter->pg && !iter->pg->index)
1898 iter->pg = iter->pg->next;
1899
1900 if (!iter->pg)
1901 return NULL;
1902
1903 return iter;
1904}
1905
1906
1907
1908
1909
1910
1911
1912struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
1913{
1914 iter->index++;
1915
1916 if (iter->index >= iter->pg->index) {
1917 iter->pg = iter->pg->next;
1918 iter->index = 0;
1919
1920
1921 while (iter->pg && !iter->pg->index)
1922 iter->pg = iter->pg->next;
1923 }
1924
1925 if (!iter->pg)
1926 return NULL;
1927
1928 return iter;
1929}
1930
1931
1932
1933
1934
1935
1936
1937struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
1938{
1939 return &iter->pg->records[iter->index];
1940}
1941
1942static int
1943ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
1944{
1945 unsigned long ip;
1946 int ret;
1947
1948 ip = rec->ip;
1949
1950 if (unlikely(ftrace_disabled))
1951 return 0;
1952
1953 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
1954 if (ret) {
1955 ftrace_bug(ret, ip);
1956 return 0;
1957 }
1958 return 1;
1959}
1960
1961
1962
1963
1964
1965int __weak ftrace_arch_code_modify_prepare(void)
1966{
1967 return 0;
1968}
1969
1970
1971
1972
1973
1974int __weak ftrace_arch_code_modify_post_process(void)
1975{
1976 return 0;
1977}
1978
1979void ftrace_modify_all_code(int command)
1980{
1981 if (command & FTRACE_UPDATE_CALLS)
1982 ftrace_replace_code(1);
1983 else if (command & FTRACE_DISABLE_CALLS)
1984 ftrace_replace_code(0);
1985
1986 if (command & FTRACE_UPDATE_TRACE_FUNC)
1987 ftrace_update_ftrace_func(ftrace_trace_function);
1988
1989 if (command & FTRACE_START_FUNC_RET)
1990 ftrace_enable_ftrace_graph_caller();
1991 else if (command & FTRACE_STOP_FUNC_RET)
1992 ftrace_disable_ftrace_graph_caller();
1993}
1994
1995static int __ftrace_modify_code(void *data)
1996{
1997 int *command = data;
1998
1999 ftrace_modify_all_code(*command);
2000
2001 return 0;
2002}
2003
2004
2005
2006
2007
2008
2009
2010
2011void ftrace_run_stop_machine(int command)
2012{
2013 stop_machine(__ftrace_modify_code, &command, NULL);
2014}
2015
2016
2017
2018
2019
2020
2021
2022
2023void __weak arch_ftrace_update_code(int command)
2024{
2025 ftrace_run_stop_machine(command);
2026}
2027
2028static void ftrace_run_update_code(int command)
2029{
2030 int ret;
2031
2032 ret = ftrace_arch_code_modify_prepare();
2033 FTRACE_WARN_ON(ret);
2034 if (ret)
2035 return;
2036
2037
2038
2039
2040 function_trace_stop++;
2041
2042
2043
2044
2045
2046
2047
2048 arch_ftrace_update_code(command);
2049
2050 function_trace_stop--;
2051
2052 ret = ftrace_arch_code_modify_post_process();
2053 FTRACE_WARN_ON(ret);
2054}
2055
2056static ftrace_func_t saved_ftrace_func;
2057static int ftrace_start_up;
2058static int global_start_up;
2059
2060static void ftrace_startup_enable(int command)
2061{
2062 if (saved_ftrace_func != ftrace_trace_function) {
2063 saved_ftrace_func = ftrace_trace_function;
2064 command |= FTRACE_UPDATE_TRACE_FUNC;
2065 }
2066
2067 if (!command || !ftrace_enabled)
2068 return;
2069
2070 ftrace_run_update_code(command);
2071}
2072
2073static int ftrace_startup(struct ftrace_ops *ops, int command)
2074{
2075 bool hash_enable = true;
2076
2077 if (unlikely(ftrace_disabled))
2078 return -ENODEV;
2079
2080 ftrace_start_up++;
2081 command |= FTRACE_UPDATE_CALLS;
2082
2083
2084 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
2085 ops = &global_ops;
2086
2087 if (global_start_up)
2088 hash_enable = false;
2089 global_start_up++;
2090 }
2091
2092 ops->flags |= FTRACE_OPS_FL_ENABLED;
2093 if (hash_enable)
2094 ftrace_hash_rec_enable(ops, 1);
2095
2096 ftrace_startup_enable(command);
2097
2098 return 0;
2099}
2100
2101static void ftrace_shutdown(struct ftrace_ops *ops, int command)
2102{
2103 bool hash_disable = true;
2104
2105 if (unlikely(ftrace_disabled))
2106 return;
2107
2108 ftrace_start_up--;
2109
2110
2111
2112
2113
2114 WARN_ON_ONCE(ftrace_start_up < 0);
2115
2116 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
2117 ops = &global_ops;
2118 global_start_up--;
2119 WARN_ON_ONCE(global_start_up < 0);
2120
2121 if (global_start_up) {
2122 WARN_ON_ONCE(!ftrace_start_up);
2123 hash_disable = false;
2124 }
2125 }
2126
2127 if (hash_disable)
2128 ftrace_hash_rec_disable(ops, 1);
2129
2130 if (ops != &global_ops || !global_start_up)
2131 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2132
2133 command |= FTRACE_UPDATE_CALLS;
2134
2135 if (saved_ftrace_func != ftrace_trace_function) {
2136 saved_ftrace_func = ftrace_trace_function;
2137 command |= FTRACE_UPDATE_TRACE_FUNC;
2138 }
2139
2140 if (!command || !ftrace_enabled)
2141 return;
2142
2143 ftrace_run_update_code(command);
2144}
2145
2146static void ftrace_startup_sysctl(void)
2147{
2148 if (unlikely(ftrace_disabled))
2149 return;
2150
2151
2152 saved_ftrace_func = NULL;
2153
2154 if (ftrace_start_up)
2155 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
2156}
2157
2158static void ftrace_shutdown_sysctl(void)
2159{
2160 if (unlikely(ftrace_disabled))
2161 return;
2162
2163
2164 if (ftrace_start_up)
2165 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
2166}
2167
2168static cycle_t ftrace_update_time;
2169static unsigned long ftrace_update_cnt;
2170unsigned long ftrace_update_tot_cnt;
2171
2172static inline int ops_traces_mod(struct ftrace_ops *ops)
2173{
2174
2175
2176
2177
2178 return ftrace_hash_empty(ops->filter_hash) &&
2179 ftrace_hash_empty(ops->notrace_hash);
2180}
2181
2182
2183
2184
2185
2186
2187
2188
2189static inline bool
2190ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2191{
2192
2193 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2194 return 0;
2195
2196
2197 if (ops_traces_mod(ops))
2198 return 0;
2199
2200
2201 if (!ftrace_hash_empty(ops->filter_hash) &&
2202 !ftrace_lookup_ip(ops->filter_hash, rec->ip))
2203 return 0;
2204
2205
2206 if (ftrace_lookup_ip(ops->notrace_hash, rec->ip))
2207 return 0;
2208
2209 return 1;
2210}
2211
2212static int referenced_filters(struct dyn_ftrace *rec)
2213{
2214 struct ftrace_ops *ops;
2215 int cnt = 0;
2216
2217 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
2218 if (ops_references_rec(ops, rec))
2219 cnt++;
2220 }
2221
2222 return cnt;
2223}
2224
2225static int ftrace_update_code(struct module *mod)
2226{
2227 struct ftrace_page *pg;
2228 struct dyn_ftrace *p;
2229 cycle_t start, stop;
2230 unsigned long ref = 0;
2231 bool test = false;
2232 int i;
2233
2234
2235
2236
2237
2238
2239
2240 if (mod) {
2241 struct ftrace_ops *ops;
2242
2243 for (ops = ftrace_ops_list;
2244 ops != &ftrace_list_end; ops = ops->next) {
2245 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
2246 if (ops_traces_mod(ops))
2247 ref++;
2248 else
2249 test = true;
2250 }
2251 }
2252 }
2253
2254 start = ftrace_now(raw_smp_processor_id());
2255 ftrace_update_cnt = 0;
2256
2257 for (pg = ftrace_new_pgs; pg; pg = pg->next) {
2258
2259 for (i = 0; i < pg->index; i++) {
2260 int cnt = ref;
2261
2262
2263 if (unlikely(ftrace_disabled))
2264 return -1;
2265
2266 p = &pg->records[i];
2267 if (test)
2268 cnt += referenced_filters(p);
2269 p->flags = cnt;
2270
2271
2272
2273
2274
2275 if (!ftrace_code_disable(mod, p))
2276 break;
2277
2278 ftrace_update_cnt++;
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289 if (ftrace_start_up && cnt) {
2290 int failed = __ftrace_replace_code(p, 1);
2291 if (failed)
2292 ftrace_bug(failed, p->ip);
2293 }
2294 }
2295 }
2296
2297 ftrace_new_pgs = NULL;
2298
2299 stop = ftrace_now(raw_smp_processor_id());
2300 ftrace_update_time = stop - start;
2301 ftrace_update_tot_cnt += ftrace_update_cnt;
2302
2303 return 0;
2304}
2305
2306static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2307{
2308 int order;
2309 int cnt;
2310
2311 if (WARN_ON(!count))
2312 return -EINVAL;
2313
2314 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2315
2316
2317
2318
2319
2320 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2321 order--;
2322
2323 again:
2324 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2325
2326 if (!pg->records) {
2327
2328 if (!order)
2329 return -ENOMEM;
2330 order >>= 1;
2331 goto again;
2332 }
2333
2334 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2335 pg->size = cnt;
2336
2337 if (cnt > count)
2338 cnt = count;
2339
2340 return cnt;
2341}
2342
2343static struct ftrace_page *
2344ftrace_allocate_pages(unsigned long num_to_init)
2345{
2346 struct ftrace_page *start_pg;
2347 struct ftrace_page *pg;
2348 int order;
2349 int cnt;
2350
2351 if (!num_to_init)
2352 return 0;
2353
2354 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
2355 if (!pg)
2356 return NULL;
2357
2358
2359
2360
2361
2362
2363 for (;;) {
2364 cnt = ftrace_allocate_records(pg, num_to_init);
2365 if (cnt < 0)
2366 goto free_pages;
2367
2368 num_to_init -= cnt;
2369 if (!num_to_init)
2370 break;
2371
2372 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
2373 if (!pg->next)
2374 goto free_pages;
2375
2376 pg = pg->next;
2377 }
2378
2379 return start_pg;
2380
2381 free_pages:
2382 while (start_pg) {
2383 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
2384 free_pages((unsigned long)pg->records, order);
2385 start_pg = pg->next;
2386 kfree(pg);
2387 pg = start_pg;
2388 }
2389 pr_info("ftrace: FAILED to allocate memory for functions\n");
2390 return NULL;
2391}
2392
2393static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
2394{
2395 int cnt;
2396
2397 if (!num_to_init) {
2398 pr_info("ftrace: No functions to be traced?\n");
2399 return -1;
2400 }
2401
2402 cnt = num_to_init / ENTRIES_PER_PAGE;
2403 pr_info("ftrace: allocating %ld entries in %d pages\n",
2404 num_to_init, cnt + 1);
2405
2406 return 0;
2407}
2408
2409#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4)
2410
2411struct ftrace_iterator {
2412 loff_t pos;
2413 loff_t func_pos;
2414 struct ftrace_page *pg;
2415 struct dyn_ftrace *func;
2416 struct ftrace_func_probe *probe;
2417 struct trace_parser parser;
2418 struct ftrace_hash *hash;
2419 struct ftrace_ops *ops;
2420 int hidx;
2421 int idx;
2422 unsigned flags;
2423};
2424
2425static void *
2426t_hash_next(struct seq_file *m, loff_t *pos)
2427{
2428 struct ftrace_iterator *iter = m->private;
2429 struct hlist_node *hnd = NULL;
2430 struct hlist_head *hhd;
2431
2432 (*pos)++;
2433 iter->pos = *pos;
2434
2435 if (iter->probe)
2436 hnd = &iter->probe->node;
2437 retry:
2438 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
2439 return NULL;
2440
2441 hhd = &ftrace_func_hash[iter->hidx];
2442
2443 if (hlist_empty(hhd)) {
2444 iter->hidx++;
2445 hnd = NULL;
2446 goto retry;
2447 }
2448
2449 if (!hnd)
2450 hnd = hhd->first;
2451 else {
2452 hnd = hnd->next;
2453 if (!hnd) {
2454 iter->hidx++;
2455 goto retry;
2456 }
2457 }
2458
2459 if (WARN_ON_ONCE(!hnd))
2460 return NULL;
2461
2462 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
2463
2464 return iter;
2465}
2466
2467static void *t_hash_start(struct seq_file *m, loff_t *pos)
2468{
2469 struct ftrace_iterator *iter = m->private;
2470 void *p = NULL;
2471 loff_t l;
2472
2473 if (!(iter->flags & FTRACE_ITER_DO_HASH))
2474 return NULL;
2475
2476 if (iter->func_pos > *pos)
2477 return NULL;
2478
2479 iter->hidx = 0;
2480 for (l = 0; l <= (*pos - iter->func_pos); ) {
2481 p = t_hash_next(m, &l);
2482 if (!p)
2483 break;
2484 }
2485 if (!p)
2486 return NULL;
2487
2488
2489 iter->flags |= FTRACE_ITER_HASH;
2490
2491 return iter;
2492}
2493
2494static int
2495t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
2496{
2497 struct ftrace_func_probe *rec;
2498
2499 rec = iter->probe;
2500 if (WARN_ON_ONCE(!rec))
2501 return -EIO;
2502
2503 if (rec->ops->print)
2504 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
2505
2506 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
2507
2508 if (rec->data)
2509 seq_printf(m, ":%p", rec->data);
2510 seq_putc(m, '\n');
2511
2512 return 0;
2513}
2514
2515static void *
2516t_next(struct seq_file *m, void *v, loff_t *pos)
2517{
2518 struct ftrace_iterator *iter = m->private;
2519 struct ftrace_ops *ops = iter->ops;
2520 struct dyn_ftrace *rec = NULL;
2521
2522 if (unlikely(ftrace_disabled))
2523 return NULL;
2524
2525 if (iter->flags & FTRACE_ITER_HASH)
2526 return t_hash_next(m, pos);
2527
2528 (*pos)++;
2529 iter->pos = iter->func_pos = *pos;
2530
2531 if (iter->flags & FTRACE_ITER_PRINTALL)
2532 return t_hash_start(m, pos);
2533
2534 retry:
2535 if (iter->idx >= iter->pg->index) {
2536 if (iter->pg->next) {
2537 iter->pg = iter->pg->next;
2538 iter->idx = 0;
2539 goto retry;
2540 }
2541 } else {
2542 rec = &iter->pg->records[iter->idx++];
2543 if (((iter->flags & FTRACE_ITER_FILTER) &&
2544 !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
2545
2546 ((iter->flags & FTRACE_ITER_NOTRACE) &&
2547 !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
2548
2549 ((iter->flags & FTRACE_ITER_ENABLED) &&
2550 !(rec->flags & FTRACE_FL_ENABLED))) {
2551
2552 rec = NULL;
2553 goto retry;
2554 }
2555 }
2556
2557 if (!rec)
2558 return t_hash_start(m, pos);
2559
2560 iter->func = rec;
2561
2562 return iter;
2563}
2564
2565static void reset_iter_read(struct ftrace_iterator *iter)
2566{
2567 iter->pos = 0;
2568 iter->func_pos = 0;
2569 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
2570}
2571
2572static void *t_start(struct seq_file *m, loff_t *pos)
2573{
2574 struct ftrace_iterator *iter = m->private;
2575 struct ftrace_ops *ops = iter->ops;
2576 void *p = NULL;
2577 loff_t l;
2578
2579 mutex_lock(&ftrace_lock);
2580
2581 if (unlikely(ftrace_disabled))
2582 return NULL;
2583
2584
2585
2586
2587 if (*pos < iter->pos)
2588 reset_iter_read(iter);
2589
2590
2591
2592
2593
2594
2595 if (iter->flags & FTRACE_ITER_FILTER &&
2596 ftrace_hash_empty(ops->filter_hash)) {
2597 if (*pos > 0)
2598 return t_hash_start(m, pos);
2599 iter->flags |= FTRACE_ITER_PRINTALL;
2600
2601 iter->flags &= ~FTRACE_ITER_HASH;
2602 return iter;
2603 }
2604
2605 if (iter->flags & FTRACE_ITER_HASH)
2606 return t_hash_start(m, pos);
2607
2608
2609
2610
2611
2612
2613 iter->pg = ftrace_pages_start;
2614 iter->idx = 0;
2615 for (l = 0; l <= *pos; ) {
2616 p = t_next(m, p, &l);
2617 if (!p)
2618 break;
2619 }
2620
2621 if (!p)
2622 return t_hash_start(m, pos);
2623
2624 return iter;
2625}
2626
2627static void t_stop(struct seq_file *m, void *p)
2628{
2629 mutex_unlock(&ftrace_lock);
2630}
2631
2632static int t_show(struct seq_file *m, void *v)
2633{
2634 struct ftrace_iterator *iter = m->private;
2635 struct dyn_ftrace *rec;
2636
2637 if (iter->flags & FTRACE_ITER_HASH)
2638 return t_hash_show(m, iter);
2639
2640 if (iter->flags & FTRACE_ITER_PRINTALL) {
2641 seq_printf(m, "#### all functions enabled ####\n");
2642 return 0;
2643 }
2644
2645 rec = iter->func;
2646
2647 if (!rec)
2648 return 0;
2649
2650 seq_printf(m, "%ps", (void *)rec->ip);
2651 if (iter->flags & FTRACE_ITER_ENABLED)
2652 seq_printf(m, " (%ld)%s",
2653 rec->flags & ~FTRACE_FL_MASK,
2654 rec->flags & FTRACE_FL_REGS ? " R" : "");
2655 seq_printf(m, "\n");
2656
2657 return 0;
2658}
2659
2660static const struct seq_operations show_ftrace_seq_ops = {
2661 .start = t_start,
2662 .next = t_next,
2663 .stop = t_stop,
2664 .show = t_show,
2665};
2666
2667static int
2668ftrace_avail_open(struct inode *inode, struct file *file)
2669{
2670 struct ftrace_iterator *iter;
2671
2672 if (unlikely(ftrace_disabled))
2673 return -ENODEV;
2674
2675 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2676 if (iter) {
2677 iter->pg = ftrace_pages_start;
2678 iter->ops = &global_ops;
2679 }
2680
2681 return iter ? 0 : -ENOMEM;
2682}
2683
2684static int
2685ftrace_enabled_open(struct inode *inode, struct file *file)
2686{
2687 struct ftrace_iterator *iter;
2688
2689 if (unlikely(ftrace_disabled))
2690 return -ENODEV;
2691
2692 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2693 if (iter) {
2694 iter->pg = ftrace_pages_start;
2695 iter->flags = FTRACE_ITER_ENABLED;
2696 iter->ops = &global_ops;
2697 }
2698
2699 return iter ? 0 : -ENOMEM;
2700}
2701
2702static void ftrace_filter_reset(struct ftrace_hash *hash)
2703{
2704 mutex_lock(&ftrace_lock);
2705 ftrace_hash_clear(hash);
2706 mutex_unlock(&ftrace_lock);
2707}
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725int
2726ftrace_regex_open(struct ftrace_ops *ops, int flag,
2727 struct inode *inode, struct file *file)
2728{
2729 struct ftrace_iterator *iter;
2730 struct ftrace_hash *hash;
2731 int ret = 0;
2732
2733 ftrace_ops_init(ops);
2734
2735 if (unlikely(ftrace_disabled))
2736 return -ENODEV;
2737
2738 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2739 if (!iter)
2740 return -ENOMEM;
2741
2742 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
2743 kfree(iter);
2744 return -ENOMEM;
2745 }
2746
2747 iter->ops = ops;
2748 iter->flags = flag;
2749
2750 mutex_lock(&ops->regex_lock);
2751
2752 if (flag & FTRACE_ITER_NOTRACE)
2753 hash = ops->notrace_hash;
2754 else
2755 hash = ops->filter_hash;
2756
2757 if (file->f_mode & FMODE_WRITE) {
2758 iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
2759 if (!iter->hash) {
2760 trace_parser_put(&iter->parser);
2761 kfree(iter);
2762 ret = -ENOMEM;
2763 goto out_unlock;
2764 }
2765 }
2766
2767 if ((file->f_mode & FMODE_WRITE) &&
2768 (file->f_flags & O_TRUNC))
2769 ftrace_filter_reset(iter->hash);
2770
2771 if (file->f_mode & FMODE_READ) {
2772 iter->pg = ftrace_pages_start;
2773
2774 ret = seq_open(file, &show_ftrace_seq_ops);
2775 if (!ret) {
2776 struct seq_file *m = file->private_data;
2777 m->private = iter;
2778 } else {
2779
2780 free_ftrace_hash(iter->hash);
2781 trace_parser_put(&iter->parser);
2782 kfree(iter);
2783 }
2784 } else
2785 file->private_data = iter;
2786
2787 out_unlock:
2788 mutex_unlock(&ops->regex_lock);
2789
2790 return ret;
2791}
2792
2793static int
2794ftrace_filter_open(struct inode *inode, struct file *file)
2795{
2796 return ftrace_regex_open(&global_ops,
2797 FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
2798 inode, file);
2799}
2800
2801static int
2802ftrace_notrace_open(struct inode *inode, struct file *file)
2803{
2804 return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
2805 inode, file);
2806}
2807
2808static int ftrace_match(char *str, char *regex, int len, int type)
2809{
2810 int matched = 0;
2811 int slen;
2812
2813 switch (type) {
2814 case MATCH_FULL:
2815 if (strcmp(str, regex) == 0)
2816 matched = 1;
2817 break;
2818 case MATCH_FRONT_ONLY:
2819 if (strncmp(str, regex, len) == 0)
2820 matched = 1;
2821 break;
2822 case MATCH_MIDDLE_ONLY:
2823 if (strstr(str, regex))
2824 matched = 1;
2825 break;
2826 case MATCH_END_ONLY:
2827 slen = strlen(str);
2828 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
2829 matched = 1;
2830 break;
2831 }
2832
2833 return matched;
2834}
2835
2836static int
2837enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
2838{
2839 struct ftrace_func_entry *entry;
2840 int ret = 0;
2841
2842 entry = ftrace_lookup_ip(hash, rec->ip);
2843 if (not) {
2844
2845 if (!entry)
2846 return 0;
2847
2848 free_hash_entry(hash, entry);
2849 } else {
2850
2851 if (entry)
2852 return 0;
2853
2854 ret = add_hash_entry(hash, rec->ip);
2855 }
2856 return ret;
2857}
2858
2859static int
2860ftrace_match_record(struct dyn_ftrace *rec, char *mod,
2861 char *regex, int len, int type)
2862{
2863 char str[KSYM_SYMBOL_LEN];
2864 char *modname;
2865
2866 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
2867
2868 if (mod) {
2869
2870 if (!modname || strcmp(modname, mod))
2871 return 0;
2872
2873
2874 if (!len)
2875 return 1;
2876 }
2877
2878 return ftrace_match(str, regex, len, type);
2879}
2880
2881static int
2882match_records(struct ftrace_hash *hash, char *buff,
2883 int len, char *mod, int not)
2884{
2885 unsigned search_len = 0;
2886 struct ftrace_page *pg;
2887 struct dyn_ftrace *rec;
2888 int type = MATCH_FULL;
2889 char *search = buff;
2890 int found = 0;
2891 int ret;
2892
2893 if (len) {
2894 type = filter_parse_regex(buff, len, &search, ¬);
2895 search_len = strlen(search);
2896 }
2897
2898 mutex_lock(&ftrace_lock);
2899
2900 if (unlikely(ftrace_disabled))
2901 goto out_unlock;
2902
2903 do_for_each_ftrace_rec(pg, rec) {
2904 if (ftrace_match_record(rec, mod, search, search_len, type)) {
2905 ret = enter_record(hash, rec, not);
2906 if (ret < 0) {
2907 found = ret;
2908 goto out_unlock;
2909 }
2910 found = 1;
2911 }
2912 } while_for_each_ftrace_rec();
2913 out_unlock:
2914 mutex_unlock(&ftrace_lock);
2915
2916 return found;
2917}
2918
2919static int
2920ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
2921{
2922 return match_records(hash, buff, len, NULL, 0);
2923}
2924
2925static int
2926ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
2927{
2928 int not = 0;
2929
2930
2931 if (strcmp(buff, "*") == 0)
2932 buff[0] = 0;
2933
2934
2935 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
2936 buff[0] = 0;
2937 not = 1;
2938 }
2939
2940 return match_records(hash, buff, strlen(buff), mod, not);
2941}
2942
2943
2944
2945
2946
2947
2948static int
2949ftrace_mod_callback(struct ftrace_hash *hash,
2950 char *func, char *cmd, char *param, int enable)
2951{
2952 char *mod;
2953 int ret = -EINVAL;
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964 if (!param)
2965 return ret;
2966
2967 mod = strsep(¶m, ":");
2968 if (!strlen(mod))
2969 return ret;
2970
2971 ret = ftrace_match_module_records(hash, func, mod);
2972 if (!ret)
2973 ret = -EINVAL;
2974 if (ret < 0)
2975 return ret;
2976
2977 return 0;
2978}
2979
2980static struct ftrace_func_command ftrace_mod_cmd = {
2981 .name = "mod",
2982 .func = ftrace_mod_callback,
2983};
2984
2985static int __init ftrace_mod_cmd_init(void)
2986{
2987 return register_ftrace_command(&ftrace_mod_cmd);
2988}
2989core_initcall(ftrace_mod_cmd_init);
2990
2991static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
2992 struct ftrace_ops *op, struct pt_regs *pt_regs)
2993{
2994 struct ftrace_func_probe *entry;
2995 struct hlist_head *hhd;
2996 unsigned long key;
2997
2998 key = hash_long(ip, FTRACE_HASH_BITS);
2999
3000 hhd = &ftrace_func_hash[key];
3001
3002 if (hlist_empty(hhd))
3003 return;
3004
3005
3006
3007
3008
3009
3010 preempt_disable_notrace();
3011 hlist_for_each_entry_rcu_notrace(entry, hhd, node) {
3012 if (entry->ip == ip)
3013 entry->ops->func(ip, parent_ip, &entry->data);
3014 }
3015 preempt_enable_notrace();
3016}
3017
3018static struct ftrace_ops trace_probe_ops __read_mostly =
3019{
3020 .func = function_trace_probe_call,
3021 .flags = FTRACE_OPS_FL_INITIALIZED,
3022 INIT_REGEX_LOCK(trace_probe_ops)
3023};
3024
3025static int ftrace_probe_registered;
3026
3027static void __enable_ftrace_function_probe(void)
3028{
3029 int ret;
3030 int i;
3031
3032 if (ftrace_probe_registered) {
3033
3034 if (ftrace_enabled)
3035 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
3036 return;
3037 }
3038
3039 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3040 struct hlist_head *hhd = &ftrace_func_hash[i];
3041 if (hhd->first)
3042 break;
3043 }
3044
3045 if (i == FTRACE_FUNC_HASHSIZE)
3046 return;
3047
3048 ret = __register_ftrace_function(&trace_probe_ops);
3049 if (!ret)
3050 ret = ftrace_startup(&trace_probe_ops, 0);
3051
3052 ftrace_probe_registered = 1;
3053}
3054
3055static void __disable_ftrace_function_probe(void)
3056{
3057 int ret;
3058 int i;
3059
3060 if (!ftrace_probe_registered)
3061 return;
3062
3063 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3064 struct hlist_head *hhd = &ftrace_func_hash[i];
3065 if (hhd->first)
3066 return;
3067 }
3068
3069
3070 ret = __unregister_ftrace_function(&trace_probe_ops);
3071 if (!ret)
3072 ftrace_shutdown(&trace_probe_ops, 0);
3073
3074 ftrace_probe_registered = 0;
3075}
3076
3077
3078static void ftrace_free_entry(struct ftrace_func_probe *entry)
3079{
3080 if (entry->ops->free)
3081 entry->ops->free(entry->ops, entry->ip, &entry->data);
3082 kfree(entry);
3083}
3084
3085int
3086register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3087 void *data)
3088{
3089 struct ftrace_func_probe *entry;
3090 struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
3091 struct ftrace_hash *hash;
3092 struct ftrace_page *pg;
3093 struct dyn_ftrace *rec;
3094 int type, len, not;
3095 unsigned long key;
3096 int count = 0;
3097 char *search;
3098 int ret;
3099
3100 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
3101 len = strlen(search);
3102
3103
3104 if (WARN_ON(not))
3105 return -EINVAL;
3106
3107 mutex_lock(&trace_probe_ops.regex_lock);
3108
3109 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3110 if (!hash) {
3111 count = -ENOMEM;
3112 goto out;
3113 }
3114
3115 if (unlikely(ftrace_disabled)) {
3116 count = -ENODEV;
3117 goto out;
3118 }
3119
3120 mutex_lock(&ftrace_lock);
3121
3122 do_for_each_ftrace_rec(pg, rec) {
3123
3124 if (!ftrace_match_record(rec, NULL, search, len, type))
3125 continue;
3126
3127 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
3128 if (!entry) {
3129
3130 if (!count)
3131 count = -ENOMEM;
3132 goto out_unlock;
3133 }
3134
3135 count++;
3136
3137 entry->data = data;
3138
3139
3140
3141
3142
3143
3144 if (ops->init) {
3145 if (ops->init(ops, rec->ip, &entry->data) < 0) {
3146
3147 kfree(entry);
3148 continue;
3149 }
3150 }
3151
3152 ret = enter_record(hash, rec, 0);
3153 if (ret < 0) {
3154 kfree(entry);
3155 count = ret;
3156 goto out_unlock;
3157 }
3158
3159 entry->ops = ops;
3160 entry->ip = rec->ip;
3161
3162 key = hash_long(entry->ip, FTRACE_HASH_BITS);
3163 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
3164
3165 } while_for_each_ftrace_rec();
3166
3167 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
3168 if (ret < 0)
3169 count = ret;
3170
3171 __enable_ftrace_function_probe();
3172
3173 out_unlock:
3174 mutex_unlock(&ftrace_lock);
3175 out:
3176 mutex_unlock(&trace_probe_ops.regex_lock);
3177 free_ftrace_hash(hash);
3178
3179 return count;
3180}
3181
3182enum {
3183 PROBE_TEST_FUNC = 1,
3184 PROBE_TEST_DATA = 2
3185};
3186
3187static void
3188__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3189 void *data, int flags)
3190{
3191 struct ftrace_func_entry *rec_entry;
3192 struct ftrace_func_probe *entry;
3193 struct ftrace_func_probe *p;
3194 struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
3195 struct list_head free_list;
3196 struct ftrace_hash *hash;
3197 struct hlist_node *tmp;
3198 char str[KSYM_SYMBOL_LEN];
3199 int type = MATCH_FULL;
3200 int i, len = 0;
3201 char *search;
3202
3203 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
3204 glob = NULL;
3205 else if (glob) {
3206 int not;
3207
3208 type = filter_parse_regex(glob, strlen(glob), &search, ¬);
3209 len = strlen(search);
3210
3211
3212 if (WARN_ON(not))
3213 return;
3214 }
3215
3216 mutex_lock(&trace_probe_ops.regex_lock);
3217
3218 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3219 if (!hash)
3220
3221 goto out_unlock;
3222
3223 INIT_LIST_HEAD(&free_list);
3224
3225 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3226 struct hlist_head *hhd = &ftrace_func_hash[i];
3227
3228 hlist_for_each_entry_safe(entry, tmp, hhd, node) {
3229
3230
3231 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
3232 continue;
3233
3234 if ((flags & PROBE_TEST_DATA) && entry->data != data)
3235 continue;
3236
3237
3238 if (glob) {
3239 kallsyms_lookup(entry->ip, NULL, NULL,
3240 NULL, str);
3241 if (!ftrace_match(str, glob, len, type))
3242 continue;
3243 }
3244
3245 rec_entry = ftrace_lookup_ip(hash, entry->ip);
3246
3247 if (rec_entry)
3248 free_hash_entry(hash, rec_entry);
3249
3250 hlist_del_rcu(&entry->node);
3251 list_add(&entry->free_list, &free_list);
3252 }
3253 }
3254 mutex_lock(&ftrace_lock);
3255 __disable_ftrace_function_probe();
3256
3257
3258
3259
3260 ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
3261 synchronize_sched();
3262 list_for_each_entry_safe(entry, p, &free_list, free_list) {
3263 list_del(&entry->free_list);
3264 ftrace_free_entry(entry);
3265 }
3266 mutex_unlock(&ftrace_lock);
3267
3268 out_unlock:
3269 mutex_unlock(&trace_probe_ops.regex_lock);
3270 free_ftrace_hash(hash);
3271}
3272
3273void
3274unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
3275 void *data)
3276{
3277 __unregister_ftrace_function_probe(glob, ops, data,
3278 PROBE_TEST_FUNC | PROBE_TEST_DATA);
3279}
3280
3281void
3282unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
3283{
3284 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
3285}
3286
3287void unregister_ftrace_function_probe_all(char *glob)
3288{
3289 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
3290}
3291
3292static LIST_HEAD(ftrace_commands);
3293static DEFINE_MUTEX(ftrace_cmd_mutex);
3294
3295int register_ftrace_command(struct ftrace_func_command *cmd)
3296{
3297 struct ftrace_func_command *p;
3298 int ret = 0;
3299
3300 mutex_lock(&ftrace_cmd_mutex);
3301 list_for_each_entry(p, &ftrace_commands, list) {
3302 if (strcmp(cmd->name, p->name) == 0) {
3303 ret = -EBUSY;
3304 goto out_unlock;
3305 }
3306 }
3307 list_add(&cmd->list, &ftrace_commands);
3308 out_unlock:
3309 mutex_unlock(&ftrace_cmd_mutex);
3310
3311 return ret;
3312}
3313
3314int unregister_ftrace_command(struct ftrace_func_command *cmd)
3315{
3316 struct ftrace_func_command *p, *n;
3317 int ret = -ENODEV;
3318
3319 mutex_lock(&ftrace_cmd_mutex);
3320 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
3321 if (strcmp(cmd->name, p->name) == 0) {
3322 ret = 0;
3323 list_del_init(&p->list);
3324 goto out_unlock;
3325 }
3326 }
3327 out_unlock:
3328 mutex_unlock(&ftrace_cmd_mutex);
3329
3330 return ret;
3331}
3332
3333static int ftrace_process_regex(struct ftrace_hash *hash,
3334 char *buff, int len, int enable)
3335{
3336 char *func, *command, *next = buff;
3337 struct ftrace_func_command *p;
3338 int ret = -EINVAL;
3339
3340 func = strsep(&next, ":");
3341
3342 if (!next) {
3343 ret = ftrace_match_records(hash, func, len);
3344 if (!ret)
3345 ret = -EINVAL;
3346 if (ret < 0)
3347 return ret;
3348 return 0;
3349 }
3350
3351
3352
3353 command = strsep(&next, ":");
3354
3355 mutex_lock(&ftrace_cmd_mutex);
3356 list_for_each_entry(p, &ftrace_commands, list) {
3357 if (strcmp(p->name, command) == 0) {
3358 ret = p->func(hash, func, command, next, enable);
3359 goto out_unlock;
3360 }
3361 }
3362 out_unlock:
3363 mutex_unlock(&ftrace_cmd_mutex);
3364
3365 return ret;
3366}
3367
3368static ssize_t
3369ftrace_regex_write(struct file *file, const char __user *ubuf,
3370 size_t cnt, loff_t *ppos, int enable)
3371{
3372 struct ftrace_iterator *iter;
3373 struct trace_parser *parser;
3374 ssize_t ret, read;
3375
3376 if (!cnt)
3377 return 0;
3378
3379 if (file->f_mode & FMODE_READ) {
3380 struct seq_file *m = file->private_data;
3381 iter = m->private;
3382 } else
3383 iter = file->private_data;
3384
3385 if (unlikely(ftrace_disabled))
3386 return -ENODEV;
3387
3388
3389
3390 parser = &iter->parser;
3391 read = trace_get_user(parser, ubuf, cnt, ppos);
3392
3393 if (read >= 0 && trace_parser_loaded(parser) &&
3394 !trace_parser_cont(parser)) {
3395 ret = ftrace_process_regex(iter->hash, parser->buffer,
3396 parser->idx, enable);
3397 trace_parser_clear(parser);
3398 if (ret < 0)
3399 goto out;
3400 }
3401
3402 ret = read;
3403 out:
3404 return ret;
3405}
3406
3407ssize_t
3408ftrace_filter_write(struct file *file, const char __user *ubuf,
3409 size_t cnt, loff_t *ppos)
3410{
3411 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
3412}
3413
3414ssize_t
3415ftrace_notrace_write(struct file *file, const char __user *ubuf,
3416 size_t cnt, loff_t *ppos)
3417{
3418 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
3419}
3420
3421static int
3422ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
3423{
3424 struct ftrace_func_entry *entry;
3425
3426 if (!ftrace_location(ip))
3427 return -EINVAL;
3428
3429 if (remove) {
3430 entry = ftrace_lookup_ip(hash, ip);
3431 if (!entry)
3432 return -ENOENT;
3433 free_hash_entry(hash, entry);
3434 return 0;
3435 }
3436
3437 return add_hash_entry(hash, ip);
3438}
3439
3440static void ftrace_ops_update_code(struct ftrace_ops *ops)
3441{
3442 if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled)
3443 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
3444}
3445
3446static int
3447ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
3448 unsigned long ip, int remove, int reset, int enable)
3449{
3450 struct ftrace_hash **orig_hash;
3451 struct ftrace_hash *hash;
3452 int ret;
3453
3454
3455 if (ops->flags & FTRACE_OPS_FL_GLOBAL)
3456 ops = &global_ops;
3457
3458 if (unlikely(ftrace_disabled))
3459 return -ENODEV;
3460
3461 mutex_lock(&ops->regex_lock);
3462
3463 if (enable)
3464 orig_hash = &ops->filter_hash;
3465 else
3466 orig_hash = &ops->notrace_hash;
3467
3468 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3469 if (!hash) {
3470 ret = -ENOMEM;
3471 goto out_regex_unlock;
3472 }
3473
3474 if (reset)
3475 ftrace_filter_reset(hash);
3476 if (buf && !ftrace_match_records(hash, buf, len)) {
3477 ret = -EINVAL;
3478 goto out_regex_unlock;
3479 }
3480 if (ip) {
3481 ret = ftrace_match_addr(hash, ip, remove);
3482 if (ret < 0)
3483 goto out_regex_unlock;
3484 }
3485
3486 mutex_lock(&ftrace_lock);
3487 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3488 if (!ret)
3489 ftrace_ops_update_code(ops);
3490
3491 mutex_unlock(&ftrace_lock);
3492
3493 out_regex_unlock:
3494 mutex_unlock(&ops->regex_lock);
3495
3496 free_ftrace_hash(hash);
3497 return ret;
3498}
3499
3500static int
3501ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
3502 int reset, int enable)
3503{
3504 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
3505}
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
3518 int remove, int reset)
3519{
3520 ftrace_ops_init(ops);
3521 return ftrace_set_addr(ops, ip, remove, reset, 1);
3522}
3523EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
3524
3525static int
3526ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3527 int reset, int enable)
3528{
3529 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
3530}
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
3543 int len, int reset)
3544{
3545 ftrace_ops_init(ops);
3546 return ftrace_set_regex(ops, buf, len, reset, 1);
3547}
3548EXPORT_SYMBOL_GPL(ftrace_set_filter);
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
3562 int len, int reset)
3563{
3564 ftrace_ops_init(ops);
3565 return ftrace_set_regex(ops, buf, len, reset, 0);
3566}
3567EXPORT_SYMBOL_GPL(ftrace_set_notrace);
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
3579{
3580 ftrace_set_regex(&global_ops, buf, len, reset, 1);
3581}
3582EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
3596{
3597 ftrace_set_regex(&global_ops, buf, len, reset, 0);
3598}
3599EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
3600
3601
3602
3603
3604#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3605static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3606static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
3607
3608
3609bool ftrace_filter_param __initdata;
3610
3611static int __init set_ftrace_notrace(char *str)
3612{
3613 ftrace_filter_param = true;
3614 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
3615 return 1;
3616}
3617__setup("ftrace_notrace=", set_ftrace_notrace);
3618
3619static int __init set_ftrace_filter(char *str)
3620{
3621 ftrace_filter_param = true;
3622 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
3623 return 1;
3624}
3625__setup("ftrace_filter=", set_ftrace_filter);
3626
3627#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3628static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
3629static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
3630
3631static int __init set_graph_function(char *str)
3632{
3633 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
3634 return 1;
3635}
3636__setup("ftrace_graph_filter=", set_graph_function);
3637
3638static void __init set_ftrace_early_graph(char *buf)
3639{
3640 int ret;
3641 char *func;
3642
3643 while (buf) {
3644 func = strsep(&buf, ",");
3645
3646 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3647 func);
3648 if (ret)
3649 printk(KERN_DEBUG "ftrace: function %s not "
3650 "traceable\n", func);
3651 }
3652}
3653#endif
3654
3655void __init
3656ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
3657{
3658 char *func;
3659
3660 ftrace_ops_init(ops);
3661
3662 while (buf) {
3663 func = strsep(&buf, ",");
3664 ftrace_set_regex(ops, func, strlen(func), 0, enable);
3665 }
3666}
3667
3668static void __init set_ftrace_early_filters(void)
3669{
3670 if (ftrace_filter_buf[0])
3671 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
3672 if (ftrace_notrace_buf[0])
3673 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
3674#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3675 if (ftrace_graph_buf[0])
3676 set_ftrace_early_graph(ftrace_graph_buf);
3677#endif
3678}
3679
3680int ftrace_regex_release(struct inode *inode, struct file *file)
3681{
3682 struct seq_file *m = (struct seq_file *)file->private_data;
3683 struct ftrace_iterator *iter;
3684 struct ftrace_hash **orig_hash;
3685 struct trace_parser *parser;
3686 int filter_hash;
3687 int ret;
3688
3689 if (file->f_mode & FMODE_READ) {
3690 iter = m->private;
3691 seq_release(inode, file);
3692 } else
3693 iter = file->private_data;
3694
3695 parser = &iter->parser;
3696 if (trace_parser_loaded(parser)) {
3697 parser->buffer[parser->idx] = 0;
3698 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
3699 }
3700
3701 trace_parser_put(parser);
3702
3703 mutex_lock(&iter->ops->regex_lock);
3704
3705 if (file->f_mode & FMODE_WRITE) {
3706 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
3707
3708 if (filter_hash)
3709 orig_hash = &iter->ops->filter_hash;
3710 else
3711 orig_hash = &iter->ops->notrace_hash;
3712
3713 mutex_lock(&ftrace_lock);
3714 ret = ftrace_hash_move(iter->ops, filter_hash,
3715 orig_hash, iter->hash);
3716 if (!ret)
3717 ftrace_ops_update_code(iter->ops);
3718
3719 mutex_unlock(&ftrace_lock);
3720 }
3721
3722 mutex_unlock(&iter->ops->regex_lock);
3723 free_ftrace_hash(iter->hash);
3724 kfree(iter);
3725
3726 return 0;
3727}
3728
3729static const struct file_operations ftrace_avail_fops = {
3730 .open = ftrace_avail_open,
3731 .read = seq_read,
3732 .llseek = seq_lseek,
3733 .release = seq_release_private,
3734};
3735
3736static const struct file_operations ftrace_enabled_fops = {
3737 .open = ftrace_enabled_open,
3738 .read = seq_read,
3739 .llseek = seq_lseek,
3740 .release = seq_release_private,
3741};
3742
3743static const struct file_operations ftrace_filter_fops = {
3744 .open = ftrace_filter_open,
3745 .read = seq_read,
3746 .write = ftrace_filter_write,
3747 .llseek = ftrace_filter_lseek,
3748 .release = ftrace_regex_release,
3749};
3750
3751static const struct file_operations ftrace_notrace_fops = {
3752 .open = ftrace_notrace_open,
3753 .read = seq_read,
3754 .write = ftrace_notrace_write,
3755 .llseek = ftrace_filter_lseek,
3756 .release = ftrace_regex_release,
3757};
3758
3759#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3760
3761static DEFINE_MUTEX(graph_lock);
3762
3763int ftrace_graph_count;
3764int ftrace_graph_filter_enabled;
3765unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
3766
3767static void *
3768__g_next(struct seq_file *m, loff_t *pos)
3769{
3770 if (*pos >= ftrace_graph_count)
3771 return NULL;
3772 return &ftrace_graph_funcs[*pos];
3773}
3774
3775static void *
3776g_next(struct seq_file *m, void *v, loff_t *pos)
3777{
3778 (*pos)++;
3779 return __g_next(m, pos);
3780}
3781
3782static void *g_start(struct seq_file *m, loff_t *pos)
3783{
3784 mutex_lock(&graph_lock);
3785
3786
3787 if (!ftrace_graph_filter_enabled && !*pos)
3788 return (void *)1;
3789
3790 return __g_next(m, pos);
3791}
3792
3793static void g_stop(struct seq_file *m, void *p)
3794{
3795 mutex_unlock(&graph_lock);
3796}
3797
3798static int g_show(struct seq_file *m, void *v)
3799{
3800 unsigned long *ptr = v;
3801
3802 if (!ptr)
3803 return 0;
3804
3805 if (ptr == (unsigned long *)1) {
3806 seq_printf(m, "#### all functions enabled ####\n");
3807 return 0;
3808 }
3809
3810 seq_printf(m, "%ps\n", (void *)*ptr);
3811
3812 return 0;
3813}
3814
3815static const struct seq_operations ftrace_graph_seq_ops = {
3816 .start = g_start,
3817 .next = g_next,
3818 .stop = g_stop,
3819 .show = g_show,
3820};
3821
3822static int
3823ftrace_graph_open(struct inode *inode, struct file *file)
3824{
3825 int ret = 0;
3826
3827 if (unlikely(ftrace_disabled))
3828 return -ENODEV;
3829
3830 mutex_lock(&graph_lock);
3831 if ((file->f_mode & FMODE_WRITE) &&
3832 (file->f_flags & O_TRUNC)) {
3833 ftrace_graph_filter_enabled = 0;
3834 ftrace_graph_count = 0;
3835 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
3836 }
3837 mutex_unlock(&graph_lock);
3838
3839 if (file->f_mode & FMODE_READ)
3840 ret = seq_open(file, &ftrace_graph_seq_ops);
3841
3842 return ret;
3843}
3844
3845static int
3846ftrace_graph_release(struct inode *inode, struct file *file)
3847{
3848 if (file->f_mode & FMODE_READ)
3849 seq_release(inode, file);
3850 return 0;
3851}
3852
3853static int
3854ftrace_set_func(unsigned long *array, int *idx, char *buffer)
3855{
3856 struct dyn_ftrace *rec;
3857 struct ftrace_page *pg;
3858 int search_len;
3859 int fail = 1;
3860 int type, not;
3861 char *search;
3862 bool exists;
3863 int i;
3864
3865
3866 type = filter_parse_regex(buffer, strlen(buffer), &search, ¬);
3867 if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
3868 return -EBUSY;
3869
3870 search_len = strlen(search);
3871
3872 mutex_lock(&ftrace_lock);
3873
3874 if (unlikely(ftrace_disabled)) {
3875 mutex_unlock(&ftrace_lock);
3876 return -ENODEV;
3877 }
3878
3879 do_for_each_ftrace_rec(pg, rec) {
3880
3881 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
3882
3883 exists = false;
3884 for (i = 0; i < *idx; i++) {
3885 if (array[i] == rec->ip) {
3886 exists = true;
3887 break;
3888 }
3889 }
3890
3891 if (!not) {
3892 fail = 0;
3893 if (!exists) {
3894 array[(*idx)++] = rec->ip;
3895 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
3896 goto out;
3897 }
3898 } else {
3899 if (exists) {
3900 array[i] = array[--(*idx)];
3901 array[*idx] = 0;
3902 fail = 0;
3903 }
3904 }
3905 }
3906 } while_for_each_ftrace_rec();
3907out:
3908 mutex_unlock(&ftrace_lock);
3909
3910 if (fail)
3911 return -EINVAL;
3912
3913 ftrace_graph_filter_enabled = !!(*idx);
3914
3915 return 0;
3916}
3917
3918static ssize_t
3919ftrace_graph_write(struct file *file, const char __user *ubuf,
3920 size_t cnt, loff_t *ppos)
3921{
3922 struct trace_parser parser;
3923 ssize_t read, ret;
3924
3925 if (!cnt)
3926 return 0;
3927
3928 mutex_lock(&graph_lock);
3929
3930 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
3931 ret = -ENOMEM;
3932 goto out_unlock;
3933 }
3934
3935 read = trace_get_user(&parser, ubuf, cnt, ppos);
3936
3937 if (read >= 0 && trace_parser_loaded((&parser))) {
3938 parser.buffer[parser.idx] = 0;
3939
3940
3941 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3942 parser.buffer);
3943 if (ret)
3944 goto out_free;
3945 }
3946
3947 ret = read;
3948
3949out_free:
3950 trace_parser_put(&parser);
3951out_unlock:
3952 mutex_unlock(&graph_lock);
3953
3954 return ret;
3955}
3956
3957static const struct file_operations ftrace_graph_fops = {
3958 .open = ftrace_graph_open,
3959 .read = seq_read,
3960 .write = ftrace_graph_write,
3961 .llseek = ftrace_filter_lseek,
3962 .release = ftrace_graph_release,
3963};
3964#endif
3965
3966static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
3967{
3968
3969 trace_create_file("available_filter_functions", 0444,
3970 d_tracer, NULL, &ftrace_avail_fops);
3971
3972 trace_create_file("enabled_functions", 0444,
3973 d_tracer, NULL, &ftrace_enabled_fops);
3974
3975 trace_create_file("set_ftrace_filter", 0644, d_tracer,
3976 NULL, &ftrace_filter_fops);
3977
3978 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
3979 NULL, &ftrace_notrace_fops);
3980
3981#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3982 trace_create_file("set_graph_function", 0444, d_tracer,
3983 NULL,
3984 &ftrace_graph_fops);
3985#endif
3986
3987 return 0;
3988}
3989
3990static int ftrace_cmp_ips(const void *a, const void *b)
3991{
3992 const unsigned long *ipa = a;
3993 const unsigned long *ipb = b;
3994
3995 if (*ipa > *ipb)
3996 return 1;
3997 if (*ipa < *ipb)
3998 return -1;
3999 return 0;
4000}
4001
4002static void ftrace_swap_ips(void *a, void *b, int size)
4003{
4004 unsigned long *ipa = a;
4005 unsigned long *ipb = b;
4006 unsigned long t;
4007
4008 t = *ipa;
4009 *ipa = *ipb;
4010 *ipb = t;
4011}
4012
4013static int ftrace_process_locs(struct module *mod,
4014 unsigned long *start,
4015 unsigned long *end)
4016{
4017 struct ftrace_page *start_pg;
4018 struct ftrace_page *pg;
4019 struct dyn_ftrace *rec;
4020 unsigned long count;
4021 unsigned long *p;
4022 unsigned long addr;
4023 unsigned long flags = 0;
4024 int ret = -ENOMEM;
4025
4026 count = end - start;
4027
4028 if (!count)
4029 return 0;
4030
4031 sort(start, count, sizeof(*start),
4032 ftrace_cmp_ips, ftrace_swap_ips);
4033
4034 start_pg = ftrace_allocate_pages(count);
4035 if (!start_pg)
4036 return -ENOMEM;
4037
4038 mutex_lock(&ftrace_lock);
4039
4040
4041
4042
4043
4044
4045 if (!mod) {
4046 WARN_ON(ftrace_pages || ftrace_pages_start);
4047
4048 ftrace_pages = ftrace_pages_start = start_pg;
4049 } else {
4050 if (!ftrace_pages)
4051 goto out;
4052
4053 if (WARN_ON(ftrace_pages->next)) {
4054
4055 while (ftrace_pages->next)
4056 ftrace_pages = ftrace_pages->next;
4057 }
4058
4059 ftrace_pages->next = start_pg;
4060 }
4061
4062 p = start;
4063 pg = start_pg;
4064 while (p < end) {
4065 addr = ftrace_call_adjust(*p++);
4066
4067
4068
4069
4070
4071
4072 if (!addr)
4073 continue;
4074
4075 if (pg->index == pg->size) {
4076
4077 if (WARN_ON(!pg->next))
4078 break;
4079 pg = pg->next;
4080 }
4081
4082 rec = &pg->records[pg->index++];
4083 rec->ip = addr;
4084 }
4085
4086
4087 WARN_ON(pg->next);
4088
4089
4090 ftrace_pages = pg;
4091
4092
4093 ftrace_new_pgs = start_pg;
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103 if (!mod)
4104 local_irq_save(flags);
4105 ftrace_update_code(mod);
4106 if (!mod)
4107 local_irq_restore(flags);
4108 ret = 0;
4109 out:
4110 mutex_unlock(&ftrace_lock);
4111
4112 return ret;
4113}
4114
4115#ifdef CONFIG_MODULES
4116
4117#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4118
4119void ftrace_release_mod(struct module *mod)
4120{
4121 struct dyn_ftrace *rec;
4122 struct ftrace_page **last_pg;
4123 struct ftrace_page *pg;
4124 int order;
4125
4126 mutex_lock(&ftrace_lock);
4127
4128 if (ftrace_disabled)
4129 goto out_unlock;
4130
4131
4132
4133
4134
4135 last_pg = &ftrace_pages_start;
4136 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
4137 rec = &pg->records[0];
4138 if (within_module_core(rec->ip, mod)) {
4139
4140
4141
4142
4143 if (WARN_ON(pg == ftrace_pages_start))
4144 goto out_unlock;
4145
4146
4147 if (pg == ftrace_pages)
4148 ftrace_pages = next_to_ftrace_page(last_pg);
4149
4150 *last_pg = pg->next;
4151 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
4152 free_pages((unsigned long)pg->records, order);
4153 kfree(pg);
4154 } else
4155 last_pg = &pg->next;
4156 }
4157 out_unlock:
4158 mutex_unlock(&ftrace_lock);
4159}
4160
4161static void ftrace_init_module(struct module *mod,
4162 unsigned long *start, unsigned long *end)
4163{
4164 if (ftrace_disabled || start == end)
4165 return;
4166 ftrace_process_locs(mod, start, end);
4167}
4168
4169static int ftrace_module_notify_enter(struct notifier_block *self,
4170 unsigned long val, void *data)
4171{
4172 struct module *mod = data;
4173
4174 if (val == MODULE_STATE_COMING)
4175 ftrace_init_module(mod, mod->ftrace_callsites,
4176 mod->ftrace_callsites +
4177 mod->num_ftrace_callsites);
4178 return 0;
4179}
4180
4181static int ftrace_module_notify_exit(struct notifier_block *self,
4182 unsigned long val, void *data)
4183{
4184 struct module *mod = data;
4185
4186 if (val == MODULE_STATE_GOING)
4187 ftrace_release_mod(mod);
4188
4189 return 0;
4190}
4191#else
4192static int ftrace_module_notify_enter(struct notifier_block *self,
4193 unsigned long val, void *data)
4194{
4195 return 0;
4196}
4197static int ftrace_module_notify_exit(struct notifier_block *self,
4198 unsigned long val, void *data)
4199{
4200 return 0;
4201}
4202#endif
4203
4204struct notifier_block ftrace_module_enter_nb = {
4205 .notifier_call = ftrace_module_notify_enter,
4206 .priority = INT_MAX,
4207};
4208
4209struct notifier_block ftrace_module_exit_nb = {
4210 .notifier_call = ftrace_module_notify_exit,
4211 .priority = INT_MIN,
4212};
4213
4214extern unsigned long __start_mcount_loc[];
4215extern unsigned long __stop_mcount_loc[];
4216
4217void __init ftrace_init(void)
4218{
4219 unsigned long count, addr, flags;
4220 int ret;
4221
4222
4223 addr = (unsigned long)ftrace_stub;
4224
4225 local_irq_save(flags);
4226 ftrace_dyn_arch_init(&addr);
4227 local_irq_restore(flags);
4228
4229
4230 if (addr)
4231 goto failed;
4232
4233 count = __stop_mcount_loc - __start_mcount_loc;
4234
4235 ret = ftrace_dyn_table_alloc(count);
4236 if (ret)
4237 goto failed;
4238
4239 last_ftrace_enabled = ftrace_enabled = 1;
4240
4241 ret = ftrace_process_locs(NULL,
4242 __start_mcount_loc,
4243 __stop_mcount_loc);
4244
4245 ret = register_module_notifier(&ftrace_module_enter_nb);
4246 if (ret)
4247 pr_warning("Failed to register trace ftrace module enter notifier\n");
4248
4249 ret = register_module_notifier(&ftrace_module_exit_nb);
4250 if (ret)
4251 pr_warning("Failed to register trace ftrace module exit notifier\n");
4252
4253 set_ftrace_early_filters();
4254
4255 return;
4256 failed:
4257 ftrace_disabled = 1;
4258}
4259
4260#else
4261
4262static struct ftrace_ops global_ops = {
4263 .func = ftrace_stub,
4264 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
4265 INIT_REGEX_LOCK(global_ops)
4266};
4267
4268static int __init ftrace_nodyn_init(void)
4269{
4270 ftrace_enabled = 1;
4271 return 0;
4272}
4273core_initcall(ftrace_nodyn_init);
4274
4275static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
4276static inline void ftrace_startup_enable(int command) { }
4277
4278# define ftrace_startup(ops, command) \
4279 ({ \
4280 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4281 0; \
4282 })
4283# define ftrace_shutdown(ops, command) do { } while (0)
4284# define ftrace_startup_sysctl() do { } while (0)
4285# define ftrace_shutdown_sysctl() do { } while (0)
4286
4287static inline int
4288ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
4289{
4290 return 1;
4291}
4292
4293#endif
4294
4295static void
4296ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
4297 struct ftrace_ops *op, struct pt_regs *regs)
4298{
4299 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
4300 return;
4301
4302
4303
4304
4305
4306 preempt_disable_notrace();
4307 trace_recursion_set(TRACE_CONTROL_BIT);
4308 do_for_each_ftrace_op(op, ftrace_control_list) {
4309 if (!(op->flags & FTRACE_OPS_FL_STUB) &&
4310 !ftrace_function_local_disabled(op) &&
4311 ftrace_ops_test(op, ip, regs))
4312 op->func(ip, parent_ip, op, regs);
4313 } while_for_each_ftrace_op(op);
4314 trace_recursion_clear(TRACE_CONTROL_BIT);
4315 preempt_enable_notrace();
4316}
4317
4318static struct ftrace_ops control_ops = {
4319 .func = ftrace_ops_control_func,
4320 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
4321 INIT_REGEX_LOCK(control_ops)
4322};
4323
4324static inline void
4325__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4326 struct ftrace_ops *ignored, struct pt_regs *regs)
4327{
4328 struct ftrace_ops *op;
4329 int bit;
4330
4331 if (function_trace_stop)
4332 return;
4333
4334 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
4335 if (bit < 0)
4336 return;
4337
4338
4339
4340
4341
4342 preempt_disable_notrace();
4343 do_for_each_ftrace_op(op, ftrace_ops_list) {
4344 if (ftrace_ops_test(op, ip, regs))
4345 op->func(ip, parent_ip, op, regs);
4346 } while_for_each_ftrace_op(op);
4347 preempt_enable_notrace();
4348 trace_clear_recursion(bit);
4349}
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364#if ARCH_SUPPORTS_FTRACE_OPS
4365static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
4366 struct ftrace_ops *op, struct pt_regs *regs)
4367{
4368 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
4369}
4370#else
4371static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
4372{
4373 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
4374}
4375#endif
4376
4377static void clear_ftrace_swapper(void)
4378{
4379 struct task_struct *p;
4380 int cpu;
4381
4382 get_online_cpus();
4383 for_each_online_cpu(cpu) {
4384 p = idle_task(cpu);
4385 clear_tsk_trace_trace(p);
4386 }
4387 put_online_cpus();
4388}
4389
4390static void set_ftrace_swapper(void)
4391{
4392 struct task_struct *p;
4393 int cpu;
4394
4395 get_online_cpus();
4396 for_each_online_cpu(cpu) {
4397 p = idle_task(cpu);
4398 set_tsk_trace_trace(p);
4399 }
4400 put_online_cpus();
4401}
4402
4403static void clear_ftrace_pid(struct pid *pid)
4404{
4405 struct task_struct *p;
4406
4407 rcu_read_lock();
4408 do_each_pid_task(pid, PIDTYPE_PID, p) {
4409 clear_tsk_trace_trace(p);
4410 } while_each_pid_task(pid, PIDTYPE_PID, p);
4411 rcu_read_unlock();
4412
4413 put_pid(pid);
4414}
4415
4416static void set_ftrace_pid(struct pid *pid)
4417{
4418 struct task_struct *p;
4419
4420 rcu_read_lock();
4421 do_each_pid_task(pid, PIDTYPE_PID, p) {
4422 set_tsk_trace_trace(p);
4423 } while_each_pid_task(pid, PIDTYPE_PID, p);
4424 rcu_read_unlock();
4425}
4426
4427static void clear_ftrace_pid_task(struct pid *pid)
4428{
4429 if (pid == ftrace_swapper_pid)
4430 clear_ftrace_swapper();
4431 else
4432 clear_ftrace_pid(pid);
4433}
4434
4435static void set_ftrace_pid_task(struct pid *pid)
4436{
4437 if (pid == ftrace_swapper_pid)
4438 set_ftrace_swapper();
4439 else
4440 set_ftrace_pid(pid);
4441}
4442
4443static int ftrace_pid_add(int p)
4444{
4445 struct pid *pid;
4446 struct ftrace_pid *fpid;
4447 int ret = -EINVAL;
4448
4449 mutex_lock(&ftrace_lock);
4450
4451 if (!p)
4452 pid = ftrace_swapper_pid;
4453 else
4454 pid = find_get_pid(p);
4455
4456 if (!pid)
4457 goto out;
4458
4459 ret = 0;
4460
4461 list_for_each_entry(fpid, &ftrace_pids, list)
4462 if (fpid->pid == pid)
4463 goto out_put;
4464
4465 ret = -ENOMEM;
4466
4467 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
4468 if (!fpid)
4469 goto out_put;
4470
4471 list_add(&fpid->list, &ftrace_pids);
4472 fpid->pid = pid;
4473
4474 set_ftrace_pid_task(pid);
4475
4476 ftrace_update_pid_func();
4477 ftrace_startup_enable(0);
4478
4479 mutex_unlock(&ftrace_lock);
4480 return 0;
4481
4482out_put:
4483 if (pid != ftrace_swapper_pid)
4484 put_pid(pid);
4485
4486out:
4487 mutex_unlock(&ftrace_lock);
4488 return ret;
4489}
4490
4491static void ftrace_pid_reset(void)
4492{
4493 struct ftrace_pid *fpid, *safe;
4494
4495 mutex_lock(&ftrace_lock);
4496 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
4497 struct pid *pid = fpid->pid;
4498
4499 clear_ftrace_pid_task(pid);
4500
4501 list_del(&fpid->list);
4502 kfree(fpid);
4503 }
4504
4505 ftrace_update_pid_func();
4506 ftrace_startup_enable(0);
4507
4508 mutex_unlock(&ftrace_lock);
4509}
4510
4511static void *fpid_start(struct seq_file *m, loff_t *pos)
4512{
4513 mutex_lock(&ftrace_lock);
4514
4515 if (list_empty(&ftrace_pids) && (!*pos))
4516 return (void *) 1;
4517
4518 return seq_list_start(&ftrace_pids, *pos);
4519}
4520
4521static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
4522{
4523 if (v == (void *)1)
4524 return NULL;
4525
4526 return seq_list_next(v, &ftrace_pids, pos);
4527}
4528
4529static void fpid_stop(struct seq_file *m, void *p)
4530{
4531 mutex_unlock(&ftrace_lock);
4532}
4533
4534static int fpid_show(struct seq_file *m, void *v)
4535{
4536 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
4537
4538 if (v == (void *)1) {
4539 seq_printf(m, "no pid\n");
4540 return 0;
4541 }
4542
4543 if (fpid->pid == ftrace_swapper_pid)
4544 seq_printf(m, "swapper tasks\n");
4545 else
4546 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
4547
4548 return 0;
4549}
4550
4551static const struct seq_operations ftrace_pid_sops = {
4552 .start = fpid_start,
4553 .next = fpid_next,
4554 .stop = fpid_stop,
4555 .show = fpid_show,
4556};
4557
4558static int
4559ftrace_pid_open(struct inode *inode, struct file *file)
4560{
4561 int ret = 0;
4562
4563 if ((file->f_mode & FMODE_WRITE) &&
4564 (file->f_flags & O_TRUNC))
4565 ftrace_pid_reset();
4566
4567 if (file->f_mode & FMODE_READ)
4568 ret = seq_open(file, &ftrace_pid_sops);
4569
4570 return ret;
4571}
4572
4573static ssize_t
4574ftrace_pid_write(struct file *filp, const char __user *ubuf,
4575 size_t cnt, loff_t *ppos)
4576{
4577 char buf[64], *tmp;
4578 long val;
4579 int ret;
4580
4581 if (cnt >= sizeof(buf))
4582 return -EINVAL;
4583
4584 if (copy_from_user(&buf, ubuf, cnt))
4585 return -EFAULT;
4586
4587 buf[cnt] = 0;
4588
4589
4590
4591
4592
4593 tmp = strstrip(buf);
4594 if (strlen(tmp) == 0)
4595 return 1;
4596
4597 ret = kstrtol(tmp, 10, &val);
4598 if (ret < 0)
4599 return ret;
4600
4601 ret = ftrace_pid_add(val);
4602
4603 return ret ? ret : cnt;
4604}
4605
4606static int
4607ftrace_pid_release(struct inode *inode, struct file *file)
4608{
4609 if (file->f_mode & FMODE_READ)
4610 seq_release(inode, file);
4611
4612 return 0;
4613}
4614
4615static const struct file_operations ftrace_pid_fops = {
4616 .open = ftrace_pid_open,
4617 .write = ftrace_pid_write,
4618 .read = seq_read,
4619 .llseek = ftrace_filter_lseek,
4620 .release = ftrace_pid_release,
4621};
4622
4623static __init int ftrace_init_debugfs(void)
4624{
4625 struct dentry *d_tracer;
4626
4627 d_tracer = tracing_init_dentry();
4628 if (!d_tracer)
4629 return 0;
4630
4631 ftrace_init_dyn_debugfs(d_tracer);
4632
4633 trace_create_file("set_ftrace_pid", 0644, d_tracer,
4634 NULL, &ftrace_pid_fops);
4635
4636 ftrace_profile_debugfs(d_tracer);
4637
4638 return 0;
4639}
4640fs_initcall(ftrace_init_debugfs);
4641
4642
4643
4644
4645
4646
4647
4648
4649void ftrace_kill(void)
4650{
4651 ftrace_disabled = 1;
4652 ftrace_enabled = 0;
4653 clear_ftrace_function();
4654}
4655
4656
4657
4658
4659int ftrace_is_dead(void)
4660{
4661 return ftrace_disabled;
4662}
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675int register_ftrace_function(struct ftrace_ops *ops)
4676{
4677 int ret = -1;
4678
4679 ftrace_ops_init(ops);
4680
4681 mutex_lock(&ftrace_lock);
4682
4683 ret = __register_ftrace_function(ops);
4684 if (!ret)
4685 ret = ftrace_startup(ops, 0);
4686
4687 mutex_unlock(&ftrace_lock);
4688
4689 return ret;
4690}
4691EXPORT_SYMBOL_GPL(register_ftrace_function);
4692
4693
4694
4695
4696
4697
4698
4699int unregister_ftrace_function(struct ftrace_ops *ops)
4700{
4701 int ret;
4702
4703 mutex_lock(&ftrace_lock);
4704 ret = __unregister_ftrace_function(ops);
4705 if (!ret)
4706 ftrace_shutdown(ops, 0);
4707 mutex_unlock(&ftrace_lock);
4708
4709 return ret;
4710}
4711EXPORT_SYMBOL_GPL(unregister_ftrace_function);
4712
4713int
4714ftrace_enable_sysctl(struct ctl_table *table, int write,
4715 void __user *buffer, size_t *lenp,
4716 loff_t *ppos)
4717{
4718 int ret = -ENODEV;
4719
4720 mutex_lock(&ftrace_lock);
4721
4722 if (unlikely(ftrace_disabled))
4723 goto out;
4724
4725 ret = proc_dointvec(table, write, buffer, lenp, ppos);
4726
4727 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
4728 goto out;
4729
4730 last_ftrace_enabled = !!ftrace_enabled;
4731
4732 if (ftrace_enabled) {
4733
4734 ftrace_startup_sysctl();
4735
4736
4737 if (ftrace_ops_list != &ftrace_list_end)
4738 update_ftrace_function();
4739
4740 } else {
4741
4742 ftrace_trace_function = ftrace_stub;
4743
4744 ftrace_shutdown_sysctl();
4745 }
4746
4747 out:
4748 mutex_unlock(&ftrace_lock);
4749 return ret;
4750}
4751
4752#ifdef CONFIG_FUNCTION_GRAPH_TRACER
4753
4754static int ftrace_graph_active;
4755static struct notifier_block ftrace_suspend_notifier;
4756
4757int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
4758{
4759 return 0;
4760}
4761
4762
4763trace_func_graph_ret_t ftrace_graph_return =
4764 (trace_func_graph_ret_t)ftrace_stub;
4765trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
4766
4767
4768static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
4769{
4770 int i;
4771 int ret = 0;
4772 unsigned long flags;
4773 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
4774 struct task_struct *g, *t;
4775
4776 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
4777 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
4778 * sizeof(struct ftrace_ret_stack),
4779 GFP_KERNEL);
4780 if (!ret_stack_list[i]) {
4781 start = 0;
4782 end = i;
4783 ret = -ENOMEM;
4784 goto free;
4785 }
4786 }
4787
4788 read_lock_irqsave(&tasklist_lock, flags);
4789 do_each_thread(g, t) {
4790 if (start == end) {
4791 ret = -EAGAIN;
4792 goto unlock;
4793 }
4794
4795 if (t->ret_stack == NULL) {
4796 atomic_set(&t->tracing_graph_pause, 0);
4797 atomic_set(&t->trace_overrun, 0);
4798 t->curr_ret_stack = -1;
4799
4800 smp_wmb();
4801 t->ret_stack = ret_stack_list[start++];
4802 }
4803 } while_each_thread(g, t);
4804
4805unlock:
4806 read_unlock_irqrestore(&tasklist_lock, flags);
4807free:
4808 for (i = start; i < end; i++)
4809 kfree(ret_stack_list[i]);
4810 return ret;
4811}
4812
4813static void
4814ftrace_graph_probe_sched_switch(void *ignore,
4815 struct task_struct *prev, struct task_struct *next)
4816{
4817 unsigned long long timestamp;
4818 int index;
4819
4820
4821
4822
4823
4824 if (trace_flags & TRACE_ITER_SLEEP_TIME)
4825 return;
4826
4827 timestamp = trace_clock_local();
4828
4829 prev->ftrace_timestamp = timestamp;
4830
4831
4832 if (!next->ftrace_timestamp)
4833 return;
4834
4835
4836
4837
4838
4839 timestamp -= next->ftrace_timestamp;
4840
4841 for (index = next->curr_ret_stack; index >= 0; index--)
4842 next->ret_stack[index].calltime += timestamp;
4843}
4844
4845
4846static int start_graph_tracing(void)
4847{
4848 struct ftrace_ret_stack **ret_stack_list;
4849 int ret, cpu;
4850
4851 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
4852 sizeof(struct ftrace_ret_stack *),
4853 GFP_KERNEL);
4854
4855 if (!ret_stack_list)
4856 return -ENOMEM;
4857
4858
4859 for_each_online_cpu(cpu) {
4860 if (!idle_task(cpu)->ret_stack)
4861 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
4862 }
4863
4864 do {
4865 ret = alloc_retstack_tasklist(ret_stack_list);
4866 } while (ret == -EAGAIN);
4867
4868 if (!ret) {
4869 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4870 if (ret)
4871 pr_info("ftrace_graph: Couldn't activate tracepoint"
4872 " probe to kernel_sched_switch\n");
4873 }
4874
4875 kfree(ret_stack_list);
4876 return ret;
4877}
4878
4879
4880
4881
4882
4883
4884static int
4885ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
4886 void *unused)
4887{
4888 switch (state) {
4889 case PM_HIBERNATION_PREPARE:
4890 pause_graph_tracing();
4891 break;
4892
4893 case PM_POST_HIBERNATION:
4894 unpause_graph_tracing();
4895 break;
4896 }
4897 return NOTIFY_DONE;
4898}
4899
4900int register_ftrace_graph(trace_func_graph_ret_t retfunc,
4901 trace_func_graph_ent_t entryfunc)
4902{
4903 int ret = 0;
4904
4905 mutex_lock(&ftrace_lock);
4906
4907
4908 if (ftrace_graph_active) {
4909 ret = -EBUSY;
4910 goto out;
4911 }
4912
4913 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
4914 register_pm_notifier(&ftrace_suspend_notifier);
4915
4916 ftrace_graph_active++;
4917 ret = start_graph_tracing();
4918 if (ret) {
4919 ftrace_graph_active--;
4920 goto out;
4921 }
4922
4923 ftrace_graph_return = retfunc;
4924 ftrace_graph_entry = entryfunc;
4925
4926 ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
4927
4928out:
4929 mutex_unlock(&ftrace_lock);
4930 return ret;
4931}
4932
4933void unregister_ftrace_graph(void)
4934{
4935 mutex_lock(&ftrace_lock);
4936
4937 if (unlikely(!ftrace_graph_active))
4938 goto out;
4939
4940 ftrace_graph_active--;
4941 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
4942 ftrace_graph_entry = ftrace_graph_entry_stub;
4943 ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
4944 unregister_pm_notifier(&ftrace_suspend_notifier);
4945 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
4946
4947 out:
4948 mutex_unlock(&ftrace_lock);
4949}
4950
4951static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
4952
4953static void
4954graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
4955{
4956 atomic_set(&t->tracing_graph_pause, 0);
4957 atomic_set(&t->trace_overrun, 0);
4958 t->ftrace_timestamp = 0;
4959
4960 smp_wmb();
4961 t->ret_stack = ret_stack;
4962}
4963
4964
4965
4966
4967
4968void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
4969{
4970 t->curr_ret_stack = -1;
4971
4972
4973
4974
4975 if (t->ret_stack)
4976 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
4977
4978 if (ftrace_graph_active) {
4979 struct ftrace_ret_stack *ret_stack;
4980
4981 ret_stack = per_cpu(idle_ret_stack, cpu);
4982 if (!ret_stack) {
4983 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4984 * sizeof(struct ftrace_ret_stack),
4985 GFP_KERNEL);
4986 if (!ret_stack)
4987 return;
4988 per_cpu(idle_ret_stack, cpu) = ret_stack;
4989 }
4990 graph_init_task(t, ret_stack);
4991 }
4992}
4993
4994
4995void ftrace_graph_init_task(struct task_struct *t)
4996{
4997
4998 t->ret_stack = NULL;
4999 t->curr_ret_stack = -1;
5000
5001 if (ftrace_graph_active) {
5002 struct ftrace_ret_stack *ret_stack;
5003
5004 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
5005 * sizeof(struct ftrace_ret_stack),
5006 GFP_KERNEL);
5007 if (!ret_stack)
5008 return;
5009 graph_init_task(t, ret_stack);
5010 }
5011}
5012
5013void ftrace_graph_exit_task(struct task_struct *t)
5014{
5015 struct ftrace_ret_stack *ret_stack = t->ret_stack;
5016
5017 t->ret_stack = NULL;
5018
5019 barrier();
5020
5021 kfree(ret_stack);
5022}
5023
5024void ftrace_graph_stop(void)
5025{
5026 ftrace_stop();
5027}
5028#endif
5029