2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 William Lee Irwin III
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/kprobes.h>
26 #include <linux/ftrace.h>
27 #include <linux/sysctl.h>
28 #include <linux/ctype.h>
29 #include <linux/list.h>
30 #include <linux/hash.h>
32 #include <trace/sched.h>
34 #include <asm/ftrace.h>
36 #include "trace_output.h"
37 #include "trace_stat.h"
39 #define FTRACE_WARN_ON(cond) \
45 #define FTRACE_WARN_ON_ONCE(cond) \
47 if (WARN_ON_ONCE(cond)) \
51 /* hash bits for specific function selection */
52 #define FTRACE_HASH_BITS 7
53 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
55 /* ftrace_enabled is a method to turn ftrace on or off */
56 int ftrace_enabled __read_mostly
;
57 static int last_ftrace_enabled
;
59 /* Quick disabling of function tracer. */
60 int function_trace_stop
;
63 * ftrace_disabled is set when an anomaly is discovered.
64 * ftrace_disabled is much stronger than ftrace_enabled.
66 static int ftrace_disabled __read_mostly
;
68 static DEFINE_MUTEX(ftrace_lock
);
70 static struct ftrace_ops ftrace_list_end __read_mostly
=
75 static struct ftrace_ops
*ftrace_list __read_mostly
= &ftrace_list_end
;
76 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
77 ftrace_func_t __ftrace_trace_function __read_mostly
= ftrace_stub
;
78 ftrace_func_t ftrace_pid_function __read_mostly
= ftrace_stub
;
80 static void ftrace_list_func(unsigned long ip
, unsigned long parent_ip
)
82 struct ftrace_ops
*op
= ftrace_list
;
84 /* in case someone actually ports this to alpha! */
85 read_barrier_depends();
87 while (op
!= &ftrace_list_end
) {
89 read_barrier_depends();
90 op
->func(ip
, parent_ip
);
95 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
)
97 if (!test_tsk_trace_trace(current
))
100 ftrace_pid_function(ip
, parent_ip
);
103 static void set_ftrace_pid_function(ftrace_func_t func
)
105 /* do not set ftrace_pid_function to itself! */
106 if (func
!= ftrace_pid_func
)
107 ftrace_pid_function
= func
;
111 * clear_ftrace_function - reset the ftrace function
113 * This NULLs the ftrace function and in essence stops
114 * tracing. There may be lag
116 void clear_ftrace_function(void)
118 ftrace_trace_function
= ftrace_stub
;
119 __ftrace_trace_function
= ftrace_stub
;
120 ftrace_pid_function
= ftrace_stub
;
123 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
125 * For those archs that do not test ftrace_trace_stop in their
126 * mcount call site, we need to do it from C.
128 static void ftrace_test_stop_func(unsigned long ip
, unsigned long parent_ip
)
130 if (function_trace_stop
)
133 __ftrace_trace_function(ip
, parent_ip
);
137 static int __register_ftrace_function(struct ftrace_ops
*ops
)
139 ops
->next
= ftrace_list
;
141 * We are entering ops into the ftrace_list but another
142 * CPU might be walking that list. We need to make sure
143 * the ops->next pointer is valid before another CPU sees
144 * the ops pointer included into the ftrace_list.
149 if (ftrace_enabled
) {
152 if (ops
->next
== &ftrace_list_end
)
155 func
= ftrace_list_func
;
157 if (ftrace_pid_trace
) {
158 set_ftrace_pid_function(func
);
159 func
= ftrace_pid_func
;
163 * For one func, simply call it directly.
164 * For more than one func, call the chain.
166 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
167 ftrace_trace_function
= func
;
169 __ftrace_trace_function
= func
;
170 ftrace_trace_function
= ftrace_test_stop_func
;
177 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
179 struct ftrace_ops
**p
;
182 * If we are removing the last function, then simply point
183 * to the ftrace_stub.
185 if (ftrace_list
== ops
&& ops
->next
== &ftrace_list_end
) {
186 ftrace_trace_function
= ftrace_stub
;
187 ftrace_list
= &ftrace_list_end
;
191 for (p
= &ftrace_list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
200 if (ftrace_enabled
) {
201 /* If we only have one func left, then call that directly */
202 if (ftrace_list
->next
== &ftrace_list_end
) {
203 ftrace_func_t func
= ftrace_list
->func
;
205 if (ftrace_pid_trace
) {
206 set_ftrace_pid_function(func
);
207 func
= ftrace_pid_func
;
209 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
210 ftrace_trace_function
= func
;
212 __ftrace_trace_function
= func
;
220 static void ftrace_update_pid_func(void)
224 if (ftrace_trace_function
== ftrace_stub
)
227 func
= ftrace_trace_function
;
229 if (ftrace_pid_trace
) {
230 set_ftrace_pid_function(func
);
231 func
= ftrace_pid_func
;
233 if (func
== ftrace_pid_func
)
234 func
= ftrace_pid_function
;
237 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
238 ftrace_trace_function
= func
;
240 __ftrace_trace_function
= func
;
244 #ifdef CONFIG_FUNCTION_PROFILER
245 struct ftrace_profile
{
246 struct hlist_node node
;
248 unsigned long counter
;
249 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
250 unsigned long long time
;
254 struct ftrace_profile_page
{
255 struct ftrace_profile_page
*next
;
257 struct ftrace_profile records
[];
260 struct ftrace_profile_stat
{
262 struct hlist_head
*hash
;
263 struct ftrace_profile_page
*pages
;
264 struct ftrace_profile_page
*start
;
265 struct tracer_stat stat
;
268 #define PROFILE_RECORDS_SIZE \
269 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
271 #define PROFILES_PER_PAGE \
272 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
274 static int ftrace_profile_bits __read_mostly
;
275 static int ftrace_profile_enabled __read_mostly
;
277 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
278 static DEFINE_MUTEX(ftrace_profile_lock
);
280 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
282 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
285 function_stat_next(void *v
, int idx
)
287 struct ftrace_profile
*rec
= v
;
288 struct ftrace_profile_page
*pg
;
290 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
294 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
298 rec
= &pg
->records
[0];
306 static void *function_stat_start(struct tracer_stat
*trace
)
308 struct ftrace_profile_stat
*stat
=
309 container_of(trace
, struct ftrace_profile_stat
, stat
);
311 if (!stat
|| !stat
->start
)
314 return function_stat_next(&stat
->start
->records
[0], 0);
317 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
318 /* function graph compares on total time */
319 static int function_stat_cmp(void *p1
, void *p2
)
321 struct ftrace_profile
*a
= p1
;
322 struct ftrace_profile
*b
= p2
;
324 if (a
->time
< b
->time
)
326 if (a
->time
> b
->time
)
332 /* not function graph compares against hits */
333 static int function_stat_cmp(void *p1
, void *p2
)
335 struct ftrace_profile
*a
= p1
;
336 struct ftrace_profile
*b
= p2
;
338 if (a
->counter
< b
->counter
)
340 if (a
->counter
> b
->counter
)
347 static int function_stat_headers(struct seq_file
*m
)
349 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
350 seq_printf(m
, " Function "
355 seq_printf(m
, " Function Hit\n"
361 static int function_stat_show(struct seq_file
*m
, void *v
)
363 struct ftrace_profile
*rec
= v
;
364 char str
[KSYM_SYMBOL_LEN
];
365 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
366 static DEFINE_MUTEX(mutex
);
367 static struct trace_seq s
;
368 unsigned long long avg
;
371 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
372 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
374 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
377 do_div(avg
, rec
->counter
);
381 trace_print_graph_duration(rec
->time
, &s
);
382 trace_seq_puts(&s
, " ");
383 trace_print_graph_duration(avg
, &s
);
384 trace_print_seq(m
, &s
);
385 mutex_unlock(&mutex
);
392 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
394 struct ftrace_profile_page
*pg
;
396 pg
= stat
->pages
= stat
->start
;
399 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
404 memset(stat
->hash
, 0,
405 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
408 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
410 struct ftrace_profile_page
*pg
;
415 /* If we already allocated, do nothing */
419 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
423 #ifdef CONFIG_DYNAMIC_FTRACE
424 functions
= ftrace_update_tot_cnt
;
427 * We do not know the number of functions that exist because
428 * dynamic tracing is what counts them. With past experience
429 * we have around 20K functions. That should be more than enough.
430 * It is highly unlikely we will execute every function in
436 pg
= stat
->start
= stat
->pages
;
438 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
440 for (i
= 0; i
< pages
; i
++) {
441 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
452 unsigned long tmp
= (unsigned long)pg
;
458 free_page((unsigned long)stat
->pages
);
465 static int ftrace_profile_init_cpu(int cpu
)
467 struct ftrace_profile_stat
*stat
;
470 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
473 /* If the profile is already created, simply reset it */
474 ftrace_profile_reset(stat
);
479 * We are profiling all functions, but usually only a few thousand
480 * functions are hit. We'll make a hash of 1024 items.
482 size
= FTRACE_PROFILE_HASH_SIZE
;
484 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
489 if (!ftrace_profile_bits
) {
492 for (; size
; size
>>= 1)
493 ftrace_profile_bits
++;
496 /* Preallocate the function profiling pages */
497 if (ftrace_profile_pages_init(stat
) < 0) {
506 static int ftrace_profile_init(void)
511 for_each_online_cpu(cpu
) {
512 ret
= ftrace_profile_init_cpu(cpu
);
520 /* interrupts must be disabled */
521 static struct ftrace_profile
*
522 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
524 struct ftrace_profile
*rec
;
525 struct hlist_head
*hhd
;
526 struct hlist_node
*n
;
529 key
= hash_long(ip
, ftrace_profile_bits
);
530 hhd
= &stat
->hash
[key
];
532 if (hlist_empty(hhd
))
535 hlist_for_each_entry_rcu(rec
, n
, hhd
, node
) {
543 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
544 struct ftrace_profile
*rec
)
548 key
= hash_long(rec
->ip
, ftrace_profile_bits
);
549 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
553 * The memory is already allocated, this simply finds a new record to use.
555 static struct ftrace_profile
*
556 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
558 struct ftrace_profile
*rec
= NULL
;
560 /* prevent recursion (from NMIs) */
561 if (atomic_inc_return(&stat
->disabled
) != 1)
565 * Try to find the function again since an NMI
566 * could have added it
568 rec
= ftrace_find_profiled_func(stat
, ip
);
572 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
573 if (!stat
->pages
->next
)
575 stat
->pages
= stat
->pages
->next
;
578 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
580 ftrace_add_profile(stat
, rec
);
583 atomic_dec(&stat
->disabled
);
589 function_profile_call(unsigned long ip
, unsigned long parent_ip
)
591 struct ftrace_profile_stat
*stat
;
592 struct ftrace_profile
*rec
;
595 if (!ftrace_profile_enabled
)
598 local_irq_save(flags
);
600 stat
= &__get_cpu_var(ftrace_profile_stats
);
604 rec
= ftrace_find_profiled_func(stat
, ip
);
606 rec
= ftrace_profile_alloc(stat
, ip
);
613 local_irq_restore(flags
);
616 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
617 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
619 function_profile_call(trace
->func
, 0);
623 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
625 struct ftrace_profile_stat
*stat
;
626 unsigned long long calltime
;
627 struct ftrace_profile
*rec
;
630 local_irq_save(flags
);
631 stat
= &__get_cpu_var(ftrace_profile_stats
);
635 calltime
= trace
->rettime
- trace
->calltime
;
637 if (!(trace_flags
& TRACE_ITER_GRAPH_TIME
)) {
640 index
= trace
->depth
;
642 /* Append this call time to the parent time to subtract */
644 current
->ret_stack
[index
- 1].subtime
+= calltime
;
646 if (current
->ret_stack
[index
].subtime
< calltime
)
647 calltime
-= current
->ret_stack
[index
].subtime
;
652 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
654 rec
->time
+= calltime
;
657 local_irq_restore(flags
);
660 static int register_ftrace_profiler(void)
662 return register_ftrace_graph(&profile_graph_return
,
663 &profile_graph_entry
);
666 static void unregister_ftrace_profiler(void)
668 unregister_ftrace_graph();
671 static struct ftrace_ops ftrace_profile_ops __read_mostly
=
673 .func
= function_profile_call
,
676 static int register_ftrace_profiler(void)
678 return register_ftrace_function(&ftrace_profile_ops
);
681 static void unregister_ftrace_profiler(void)
683 unregister_ftrace_function(&ftrace_profile_ops
);
685 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
688 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
689 size_t cnt
, loff_t
*ppos
)
692 char buf
[64]; /* big enough to hold a number */
695 if (cnt
>= sizeof(buf
))
698 if (copy_from_user(&buf
, ubuf
, cnt
))
703 ret
= strict_strtoul(buf
, 10, &val
);
709 mutex_lock(&ftrace_profile_lock
);
710 if (ftrace_profile_enabled
^ val
) {
712 ret
= ftrace_profile_init();
718 ret
= register_ftrace_profiler();
723 ftrace_profile_enabled
= 1;
725 ftrace_profile_enabled
= 0;
726 unregister_ftrace_profiler();
730 mutex_unlock(&ftrace_profile_lock
);
738 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
739 size_t cnt
, loff_t
*ppos
)
741 char buf
[64]; /* big enough to hold a number */
744 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
745 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
748 static const struct file_operations ftrace_profile_fops
= {
749 .open
= tracing_open_generic
,
750 .read
= ftrace_profile_read
,
751 .write
= ftrace_profile_write
,
754 /* used to initialize the real stat files */
755 static struct tracer_stat function_stats __initdata
= {
757 .stat_start
= function_stat_start
,
758 .stat_next
= function_stat_next
,
759 .stat_cmp
= function_stat_cmp
,
760 .stat_headers
= function_stat_headers
,
761 .stat_show
= function_stat_show
764 static void ftrace_profile_debugfs(struct dentry
*d_tracer
)
766 struct ftrace_profile_stat
*stat
;
767 struct dentry
*entry
;
772 for_each_possible_cpu(cpu
) {
773 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
775 /* allocate enough for function name + cpu number */
776 name
= kmalloc(32, GFP_KERNEL
);
779 * The files created are permanent, if something happens
780 * we still do not free memory.
784 "Could not allocate stat file for cpu %d\n",
788 stat
->stat
= function_stats
;
789 snprintf(name
, 32, "function%d", cpu
);
790 stat
->stat
.name
= name
;
791 ret
= register_stat_tracer(&stat
->stat
);
794 "Could not register function stat for cpu %d\n",
801 entry
= debugfs_create_file("function_profile_enabled", 0644,
802 d_tracer
, NULL
, &ftrace_profile_fops
);
804 pr_warning("Could not create debugfs "
805 "'function_profile_enabled' entry\n");
808 #else /* CONFIG_FUNCTION_PROFILER */
809 static void ftrace_profile_debugfs(struct dentry
*d_tracer
)
812 #endif /* CONFIG_FUNCTION_PROFILER */
814 /* set when tracing only a pid */
815 struct pid
*ftrace_pid_trace
;
816 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
818 #ifdef CONFIG_DYNAMIC_FTRACE
820 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
821 # error Dynamic ftrace depends on MCOUNT_RECORD
824 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
826 struct ftrace_func_probe
{
827 struct hlist_node node
;
828 struct ftrace_probe_ops
*ops
;
836 FTRACE_ENABLE_CALLS
= (1 << 0),
837 FTRACE_DISABLE_CALLS
= (1 << 1),
838 FTRACE_UPDATE_TRACE_FUNC
= (1 << 2),
839 FTRACE_ENABLE_MCOUNT
= (1 << 3),
840 FTRACE_DISABLE_MCOUNT
= (1 << 4),
841 FTRACE_START_FUNC_RET
= (1 << 5),
842 FTRACE_STOP_FUNC_RET
= (1 << 6),
845 static int ftrace_filtered
;
847 static struct dyn_ftrace
*ftrace_new_addrs
;
849 static DEFINE_MUTEX(ftrace_regex_lock
);
852 struct ftrace_page
*next
;
854 struct dyn_ftrace records
[];
857 #define ENTRIES_PER_PAGE \
858 ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
860 /* estimate from running different kernels */
861 #define NR_TO_INIT 10000
863 static struct ftrace_page
*ftrace_pages_start
;
864 static struct ftrace_page
*ftrace_pages
;
866 static struct dyn_ftrace
*ftrace_free_records
;
869 * This is a double for. Do not use 'break' to break out of the loop,
870 * you must use a goto.
872 #define do_for_each_ftrace_rec(pg, rec) \
873 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
875 for (_____i = 0; _____i < pg->index; _____i++) { \
876 rec = &pg->records[_____i];
878 #define while_for_each_ftrace_rec() \
882 #ifdef CONFIG_KPROBES
884 static int frozen_record_count
;
886 static inline void freeze_record(struct dyn_ftrace
*rec
)
888 if (!(rec
->flags
& FTRACE_FL_FROZEN
)) {
889 rec
->flags
|= FTRACE_FL_FROZEN
;
890 frozen_record_count
++;
894 static inline void unfreeze_record(struct dyn_ftrace
*rec
)
896 if (rec
->flags
& FTRACE_FL_FROZEN
) {
897 rec
->flags
&= ~FTRACE_FL_FROZEN
;
898 frozen_record_count
--;
902 static inline int record_frozen(struct dyn_ftrace
*rec
)
904 return rec
->flags
& FTRACE_FL_FROZEN
;
907 # define freeze_record(rec) ({ 0; })
908 # define unfreeze_record(rec) ({ 0; })
909 # define record_frozen(rec) ({ 0; })
910 #endif /* CONFIG_KPROBES */
912 static void ftrace_free_rec(struct dyn_ftrace
*rec
)
914 rec
->freelist
= ftrace_free_records
;
915 ftrace_free_records
= rec
;
916 rec
->flags
|= FTRACE_FL_FREE
;
919 void ftrace_release(void *start
, unsigned long size
)
921 struct dyn_ftrace
*rec
;
922 struct ftrace_page
*pg
;
923 unsigned long s
= (unsigned long)start
;
924 unsigned long e
= s
+ size
;
926 if (ftrace_disabled
|| !start
)
929 mutex_lock(&ftrace_lock
);
930 do_for_each_ftrace_rec(pg
, rec
) {
931 if ((rec
->ip
>= s
) && (rec
->ip
< e
)) {
933 * rec->ip is changed in ftrace_free_rec()
934 * It should not between s and e if record was freed.
936 FTRACE_WARN_ON(rec
->flags
& FTRACE_FL_FREE
);
937 ftrace_free_rec(rec
);
939 } while_for_each_ftrace_rec();
940 mutex_unlock(&ftrace_lock
);
943 static struct dyn_ftrace
*ftrace_alloc_dyn_node(unsigned long ip
)
945 struct dyn_ftrace
*rec
;
947 /* First check for freed records */
948 if (ftrace_free_records
) {
949 rec
= ftrace_free_records
;
951 if (unlikely(!(rec
->flags
& FTRACE_FL_FREE
))) {
952 FTRACE_WARN_ON_ONCE(1);
953 ftrace_free_records
= NULL
;
957 ftrace_free_records
= rec
->freelist
;
958 memset(rec
, 0, sizeof(*rec
));
962 if (ftrace_pages
->index
== ENTRIES_PER_PAGE
) {
963 if (!ftrace_pages
->next
) {
964 /* allocate another page */
966 (void *)get_zeroed_page(GFP_KERNEL
);
967 if (!ftrace_pages
->next
)
970 ftrace_pages
= ftrace_pages
->next
;
973 return &ftrace_pages
->records
[ftrace_pages
->index
++];
976 static struct dyn_ftrace
*
977 ftrace_record_ip(unsigned long ip
)
979 struct dyn_ftrace
*rec
;
984 rec
= ftrace_alloc_dyn_node(ip
);
989 rec
->newlist
= ftrace_new_addrs
;
990 ftrace_new_addrs
= rec
;
995 static void print_ip_ins(const char *fmt
, unsigned char *p
)
999 printk(KERN_CONT
"%s", fmt
);
1001 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1002 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1005 static void ftrace_bug(int failed
, unsigned long ip
)
1009 FTRACE_WARN_ON_ONCE(1);
1010 pr_info("ftrace faulted on modifying ");
1014 FTRACE_WARN_ON_ONCE(1);
1015 pr_info("ftrace failed to modify ");
1017 print_ip_ins(" actual: ", (unsigned char *)ip
);
1018 printk(KERN_CONT
"\n");
1021 FTRACE_WARN_ON_ONCE(1);
1022 pr_info("ftrace faulted on writing ");
1026 FTRACE_WARN_ON_ONCE(1);
1027 pr_info("ftrace faulted on unknown error ");
1034 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
1036 unsigned long ftrace_addr
;
1037 unsigned long ip
, fl
;
1039 ftrace_addr
= (unsigned long)FTRACE_ADDR
;
1044 * If this record is not to be traced and
1045 * it is not enabled then do nothing.
1047 * If this record is not to be traced and
1048 * it is enabled then disable it.
1051 if (rec
->flags
& FTRACE_FL_NOTRACE
) {
1052 if (rec
->flags
& FTRACE_FL_ENABLED
)
1053 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1057 } else if (ftrace_filtered
&& enable
) {
1062 fl
= rec
->flags
& (FTRACE_FL_FILTER
| FTRACE_FL_ENABLED
);
1064 /* Record is filtered and enabled, do nothing */
1065 if (fl
== (FTRACE_FL_FILTER
| FTRACE_FL_ENABLED
))
1068 /* Record is not filtered or enabled, do nothing */
1072 /* Record is not filtered but enabled, disable it */
1073 if (fl
== FTRACE_FL_ENABLED
)
1074 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1076 /* Otherwise record is filtered but not enabled, enable it */
1077 rec
->flags
|= FTRACE_FL_ENABLED
;
1079 /* Disable or not filtered */
1082 /* if record is enabled, do nothing */
1083 if (rec
->flags
& FTRACE_FL_ENABLED
)
1086 rec
->flags
|= FTRACE_FL_ENABLED
;
1090 /* if record is not enabled, do nothing */
1091 if (!(rec
->flags
& FTRACE_FL_ENABLED
))
1094 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1098 if (rec
->flags
& FTRACE_FL_ENABLED
)
1099 return ftrace_make_call(rec
, ftrace_addr
);
1101 return ftrace_make_nop(NULL
, rec
, ftrace_addr
);
1104 static void ftrace_replace_code(int enable
)
1106 struct dyn_ftrace
*rec
;
1107 struct ftrace_page
*pg
;
1110 do_for_each_ftrace_rec(pg
, rec
) {
1112 * Skip over free records, records that have
1113 * failed and not converted.
1115 if (rec
->flags
& FTRACE_FL_FREE
||
1116 rec
->flags
& FTRACE_FL_FAILED
||
1117 !(rec
->flags
& FTRACE_FL_CONVERTED
))
1120 /* ignore updates to this record's mcount site */
1121 if (get_kprobe((void *)rec
->ip
)) {
1125 unfreeze_record(rec
);
1128 failed
= __ftrace_replace_code(rec
, enable
);
1130 rec
->flags
|= FTRACE_FL_FAILED
;
1131 if ((system_state
== SYSTEM_BOOTING
) ||
1132 !core_kernel_text(rec
->ip
)) {
1133 ftrace_free_rec(rec
);
1135 ftrace_bug(failed
, rec
->ip
);
1136 /* Stop processing */
1140 } while_for_each_ftrace_rec();
1144 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
1151 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
1153 ftrace_bug(ret
, ip
);
1154 rec
->flags
|= FTRACE_FL_FAILED
;
1161 * archs can override this function if they must do something
1162 * before the modifying code is performed.
1164 int __weak
ftrace_arch_code_modify_prepare(void)
1170 * archs can override this function if they must do something
1171 * after the modifying code is performed.
1173 int __weak
ftrace_arch_code_modify_post_process(void)
1178 static int __ftrace_modify_code(void *data
)
1180 int *command
= data
;
1182 if (*command
& FTRACE_ENABLE_CALLS
)
1183 ftrace_replace_code(1);
1184 else if (*command
& FTRACE_DISABLE_CALLS
)
1185 ftrace_replace_code(0);
1187 if (*command
& FTRACE_UPDATE_TRACE_FUNC
)
1188 ftrace_update_ftrace_func(ftrace_trace_function
);
1190 if (*command
& FTRACE_START_FUNC_RET
)
1191 ftrace_enable_ftrace_graph_caller();
1192 else if (*command
& FTRACE_STOP_FUNC_RET
)
1193 ftrace_disable_ftrace_graph_caller();
1198 static void ftrace_run_update_code(int command
)
1202 ret
= ftrace_arch_code_modify_prepare();
1203 FTRACE_WARN_ON(ret
);
1207 stop_machine(__ftrace_modify_code
, &command
, NULL
);
1209 ret
= ftrace_arch_code_modify_post_process();
1210 FTRACE_WARN_ON(ret
);
1213 static ftrace_func_t saved_ftrace_func
;
1214 static int ftrace_start_up
;
1216 static void ftrace_startup_enable(int command
)
1218 if (saved_ftrace_func
!= ftrace_trace_function
) {
1219 saved_ftrace_func
= ftrace_trace_function
;
1220 command
|= FTRACE_UPDATE_TRACE_FUNC
;
1223 if (!command
|| !ftrace_enabled
)
1226 ftrace_run_update_code(command
);
1229 static void ftrace_startup(int command
)
1231 if (unlikely(ftrace_disabled
))
1235 command
|= FTRACE_ENABLE_CALLS
;
1237 ftrace_startup_enable(command
);
1240 static void ftrace_shutdown(int command
)
1242 if (unlikely(ftrace_disabled
))
1246 if (!ftrace_start_up
)
1247 command
|= FTRACE_DISABLE_CALLS
;
1249 if (saved_ftrace_func
!= ftrace_trace_function
) {
1250 saved_ftrace_func
= ftrace_trace_function
;
1251 command
|= FTRACE_UPDATE_TRACE_FUNC
;
1254 if (!command
|| !ftrace_enabled
)
1257 ftrace_run_update_code(command
);
1260 static void ftrace_startup_sysctl(void)
1262 int command
= FTRACE_ENABLE_MCOUNT
;
1264 if (unlikely(ftrace_disabled
))
1267 /* Force update next time */
1268 saved_ftrace_func
= NULL
;
1269 /* ftrace_start_up is true if we want ftrace running */
1270 if (ftrace_start_up
)
1271 command
|= FTRACE_ENABLE_CALLS
;
1273 ftrace_run_update_code(command
);
1276 static void ftrace_shutdown_sysctl(void)
1278 int command
= FTRACE_DISABLE_MCOUNT
;
1280 if (unlikely(ftrace_disabled
))
1283 /* ftrace_start_up is true if ftrace is running */
1284 if (ftrace_start_up
)
1285 command
|= FTRACE_DISABLE_CALLS
;
1287 ftrace_run_update_code(command
);
1290 static cycle_t ftrace_update_time
;
1291 static unsigned long ftrace_update_cnt
;
1292 unsigned long ftrace_update_tot_cnt
;
1294 static int ftrace_update_code(struct module
*mod
)
1296 struct dyn_ftrace
*p
;
1297 cycle_t start
, stop
;
1299 start
= ftrace_now(raw_smp_processor_id());
1300 ftrace_update_cnt
= 0;
1302 while (ftrace_new_addrs
) {
1304 /* If something went wrong, bail without enabling anything */
1305 if (unlikely(ftrace_disabled
))
1308 p
= ftrace_new_addrs
;
1309 ftrace_new_addrs
= p
->newlist
;
1312 /* convert record (i.e, patch mcount-call with NOP) */
1313 if (ftrace_code_disable(mod
, p
)) {
1314 p
->flags
|= FTRACE_FL_CONVERTED
;
1315 ftrace_update_cnt
++;
1320 stop
= ftrace_now(raw_smp_processor_id());
1321 ftrace_update_time
= stop
- start
;
1322 ftrace_update_tot_cnt
+= ftrace_update_cnt
;
1327 static int __init
ftrace_dyn_table_alloc(unsigned long num_to_init
)
1329 struct ftrace_page
*pg
;
1333 /* allocate a few pages */
1334 ftrace_pages_start
= (void *)get_zeroed_page(GFP_KERNEL
);
1335 if (!ftrace_pages_start
)
1339 * Allocate a few more pages.
1341 * TODO: have some parser search vmlinux before
1342 * final linking to find all calls to ftrace.
1344 * a) know how many pages to allocate.
1346 * b) set up the table then.
1348 * The dynamic code is still necessary for
1352 pg
= ftrace_pages
= ftrace_pages_start
;
1354 cnt
= num_to_init
/ ENTRIES_PER_PAGE
;
1355 pr_info("ftrace: allocating %ld entries in %d pages\n",
1356 num_to_init
, cnt
+ 1);
1358 for (i
= 0; i
< cnt
; i
++) {
1359 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
1361 /* If we fail, we'll try later anyway */
1372 FTRACE_ITER_FILTER
= (1 << 0),
1373 FTRACE_ITER_CONT
= (1 << 1),
1374 FTRACE_ITER_NOTRACE
= (1 << 2),
1375 FTRACE_ITER_FAILURES
= (1 << 3),
1376 FTRACE_ITER_PRINTALL
= (1 << 4),
1377 FTRACE_ITER_HASH
= (1 << 5),
1380 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
1382 struct ftrace_iterator
{
1383 struct ftrace_page
*pg
;
1387 unsigned char buffer
[FTRACE_BUFF_MAX
+1];
1388 unsigned buffer_idx
;
1393 t_hash_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
1395 struct ftrace_iterator
*iter
= m
->private;
1396 struct hlist_node
*hnd
= v
;
1397 struct hlist_head
*hhd
;
1399 WARN_ON(!(iter
->flags
& FTRACE_ITER_HASH
));
1404 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
1407 hhd
= &ftrace_func_hash
[iter
->hidx
];
1409 if (hlist_empty(hhd
)) {
1428 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
1430 struct ftrace_iterator
*iter
= m
->private;
1433 iter
->flags
|= FTRACE_ITER_HASH
;
1435 return t_hash_next(m
, p
, pos
);
1438 static int t_hash_show(struct seq_file
*m
, void *v
)
1440 struct ftrace_func_probe
*rec
;
1441 struct hlist_node
*hnd
= v
;
1442 char str
[KSYM_SYMBOL_LEN
];
1444 rec
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
1446 if (rec
->ops
->print
)
1447 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
1449 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
1450 seq_printf(m
, "%s:", str
);
1452 kallsyms_lookup((unsigned long)rec
->ops
->func
, NULL
, NULL
, NULL
, str
);
1453 seq_printf(m
, "%s", str
);
1456 seq_printf(m
, ":%p", rec
->data
);
1463 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
1465 struct ftrace_iterator
*iter
= m
->private;
1466 struct dyn_ftrace
*rec
= NULL
;
1468 if (iter
->flags
& FTRACE_ITER_HASH
)
1469 return t_hash_next(m
, v
, pos
);
1473 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
1477 if (iter
->idx
>= iter
->pg
->index
) {
1478 if (iter
->pg
->next
) {
1479 iter
->pg
= iter
->pg
->next
;
1486 rec
= &iter
->pg
->records
[iter
->idx
++];
1487 if ((rec
->flags
& FTRACE_FL_FREE
) ||
1489 (!(iter
->flags
& FTRACE_ITER_FAILURES
) &&
1490 (rec
->flags
& FTRACE_FL_FAILED
)) ||
1492 ((iter
->flags
& FTRACE_ITER_FAILURES
) &&
1493 !(rec
->flags
& FTRACE_FL_FAILED
)) ||
1495 ((iter
->flags
& FTRACE_ITER_FILTER
) &&
1496 !(rec
->flags
& FTRACE_FL_FILTER
)) ||
1498 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
1499 !(rec
->flags
& FTRACE_FL_NOTRACE
))) {
1508 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
1510 struct ftrace_iterator
*iter
= m
->private;
1513 mutex_lock(&ftrace_lock
);
1515 * For set_ftrace_filter reading, if we have the filter
1516 * off, we can short cut and just print out that all
1517 * functions are enabled.
1519 if (iter
->flags
& FTRACE_ITER_FILTER
&& !ftrace_filtered
) {
1521 return t_hash_start(m
, pos
);
1522 iter
->flags
|= FTRACE_ITER_PRINTALL
;
1527 if (iter
->flags
& FTRACE_ITER_HASH
)
1528 return t_hash_start(m
, pos
);
1537 p
= t_next(m
, p
, pos
);
1540 return t_hash_start(m
, pos
);
1545 static void t_stop(struct seq_file
*m
, void *p
)
1547 mutex_unlock(&ftrace_lock
);
1550 static int t_show(struct seq_file
*m
, void *v
)
1552 struct ftrace_iterator
*iter
= m
->private;
1553 struct dyn_ftrace
*rec
= v
;
1554 char str
[KSYM_SYMBOL_LEN
];
1556 if (iter
->flags
& FTRACE_ITER_HASH
)
1557 return t_hash_show(m
, v
);
1559 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
1560 seq_printf(m
, "#### all functions enabled ####\n");
1567 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
1569 seq_printf(m
, "%s\n", str
);
1574 static struct seq_operations show_ftrace_seq_ops
= {
1582 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
1584 struct ftrace_iterator
*iter
;
1587 if (unlikely(ftrace_disabled
))
1590 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
1594 iter
->pg
= ftrace_pages_start
;
1596 ret
= seq_open(file
, &show_ftrace_seq_ops
);
1598 struct seq_file
*m
= file
->private_data
;
1608 int ftrace_avail_release(struct inode
*inode
, struct file
*file
)
1610 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
1611 struct ftrace_iterator
*iter
= m
->private;
1613 seq_release(inode
, file
);
1620 ftrace_failures_open(struct inode
*inode
, struct file
*file
)
1624 struct ftrace_iterator
*iter
;
1626 ret
= ftrace_avail_open(inode
, file
);
1628 m
= (struct seq_file
*)file
->private_data
;
1629 iter
= (struct ftrace_iterator
*)m
->private;
1630 iter
->flags
= FTRACE_ITER_FAILURES
;
1637 static void ftrace_filter_reset(int enable
)
1639 struct ftrace_page
*pg
;
1640 struct dyn_ftrace
*rec
;
1641 unsigned long type
= enable
? FTRACE_FL_FILTER
: FTRACE_FL_NOTRACE
;
1643 mutex_lock(&ftrace_lock
);
1645 ftrace_filtered
= 0;
1646 do_for_each_ftrace_rec(pg
, rec
) {
1647 if (rec
->flags
& FTRACE_FL_FAILED
)
1649 rec
->flags
&= ~type
;
1650 } while_for_each_ftrace_rec();
1651 mutex_unlock(&ftrace_lock
);
1655 ftrace_regex_open(struct inode
*inode
, struct file
*file
, int enable
)
1657 struct ftrace_iterator
*iter
;
1660 if (unlikely(ftrace_disabled
))
1663 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
1667 mutex_lock(&ftrace_regex_lock
);
1668 if ((file
->f_mode
& FMODE_WRITE
) &&
1669 !(file
->f_flags
& O_APPEND
))
1670 ftrace_filter_reset(enable
);
1672 if (file
->f_mode
& FMODE_READ
) {
1673 iter
->pg
= ftrace_pages_start
;
1674 iter
->flags
= enable
? FTRACE_ITER_FILTER
:
1675 FTRACE_ITER_NOTRACE
;
1677 ret
= seq_open(file
, &show_ftrace_seq_ops
);
1679 struct seq_file
*m
= file
->private_data
;
1684 file
->private_data
= iter
;
1685 mutex_unlock(&ftrace_regex_lock
);
1691 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
1693 return ftrace_regex_open(inode
, file
, 1);
1697 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
1699 return ftrace_regex_open(inode
, file
, 0);
1703 ftrace_regex_lseek(struct file
*file
, loff_t offset
, int origin
)
1707 if (file
->f_mode
& FMODE_READ
)
1708 ret
= seq_lseek(file
, offset
, origin
);
1710 file
->f_pos
= ret
= 1;
1723 * (static function - no need for kernel doc)
1725 * Pass in a buffer containing a glob and this function will
1726 * set search to point to the search part of the buffer and
1727 * return the type of search it is (see enum above).
1728 * This does modify buff.
1730 * Returns enum type.
1731 * search returns the pointer to use for comparison.
1732 * not returns 1 if buff started with a '!'
1736 ftrace_setup_glob(char *buff
, int len
, char **search
, int *not)
1738 int type
= MATCH_FULL
;
1741 if (buff
[0] == '!') {
1750 for (i
= 0; i
< len
; i
++) {
1751 if (buff
[i
] == '*') {
1754 type
= MATCH_END_ONLY
;
1756 if (type
== MATCH_END_ONLY
)
1757 type
= MATCH_MIDDLE_ONLY
;
1759 type
= MATCH_FRONT_ONLY
;
1769 static int ftrace_match(char *str
, char *regex
, int len
, int type
)
1776 if (strcmp(str
, regex
) == 0)
1779 case MATCH_FRONT_ONLY
:
1780 if (strncmp(str
, regex
, len
) == 0)
1783 case MATCH_MIDDLE_ONLY
:
1784 if (strstr(str
, regex
))
1787 case MATCH_END_ONLY
:
1788 ptr
= strstr(str
, regex
);
1789 if (ptr
&& (ptr
[len
] == 0))
1798 ftrace_match_record(struct dyn_ftrace
*rec
, char *regex
, int len
, int type
)
1800 char str
[KSYM_SYMBOL_LEN
];
1802 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
1803 return ftrace_match(str
, regex
, len
, type
);
1806 static void ftrace_match_records(char *buff
, int len
, int enable
)
1808 unsigned int search_len
;
1809 struct ftrace_page
*pg
;
1810 struct dyn_ftrace
*rec
;
1816 flag
= enable
? FTRACE_FL_FILTER
: FTRACE_FL_NOTRACE
;
1817 type
= ftrace_setup_glob(buff
, len
, &search
, ¬);
1819 search_len
= strlen(search
);
1821 mutex_lock(&ftrace_lock
);
1822 do_for_each_ftrace_rec(pg
, rec
) {
1824 if (rec
->flags
& FTRACE_FL_FAILED
)
1827 if (ftrace_match_record(rec
, search
, search_len
, type
)) {
1829 rec
->flags
&= ~flag
;
1834 * Only enable filtering if we have a function that
1837 if (enable
&& (rec
->flags
& FTRACE_FL_FILTER
))
1838 ftrace_filtered
= 1;
1839 } while_for_each_ftrace_rec();
1840 mutex_unlock(&ftrace_lock
);
1844 ftrace_match_module_record(struct dyn_ftrace
*rec
, char *mod
,
1845 char *regex
, int len
, int type
)
1847 char str
[KSYM_SYMBOL_LEN
];
1850 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
1852 if (!modname
|| strcmp(modname
, mod
))
1855 /* blank search means to match all funcs in the mod */
1857 return ftrace_match(str
, regex
, len
, type
);
1862 static void ftrace_match_module_records(char *buff
, char *mod
, int enable
)
1864 unsigned search_len
= 0;
1865 struct ftrace_page
*pg
;
1866 struct dyn_ftrace
*rec
;
1867 int type
= MATCH_FULL
;
1868 char *search
= buff
;
1872 flag
= enable
? FTRACE_FL_FILTER
: FTRACE_FL_NOTRACE
;
1874 /* blank or '*' mean the same */
1875 if (strcmp(buff
, "*") == 0)
1878 /* handle the case of 'dont filter this module' */
1879 if (strcmp(buff
, "!") == 0 || strcmp(buff
, "!*") == 0) {
1885 type
= ftrace_setup_glob(buff
, strlen(buff
), &search
, ¬);
1886 search_len
= strlen(search
);
1889 mutex_lock(&ftrace_lock
);
1890 do_for_each_ftrace_rec(pg
, rec
) {
1892 if (rec
->flags
& FTRACE_FL_FAILED
)
1895 if (ftrace_match_module_record(rec
, mod
,
1896 search
, search_len
, type
)) {
1898 rec
->flags
&= ~flag
;
1902 if (enable
&& (rec
->flags
& FTRACE_FL_FILTER
))
1903 ftrace_filtered
= 1;
1905 } while_for_each_ftrace_rec();
1906 mutex_unlock(&ftrace_lock
);
1910 * We register the module command as a template to show others how
1911 * to register the a command as well.
1915 ftrace_mod_callback(char *func
, char *cmd
, char *param
, int enable
)
1920 * cmd == 'mod' because we only registered this func
1921 * for the 'mod' ftrace_func_command.
1922 * But if you register one func with multiple commands,
1923 * you can tell which command was used by the cmd
1927 /* we must have a module name */
1931 mod
= strsep(¶m
, ":");
1935 ftrace_match_module_records(func
, mod
, enable
);
1939 static struct ftrace_func_command ftrace_mod_cmd
= {
1941 .func
= ftrace_mod_callback
,
1944 static int __init
ftrace_mod_cmd_init(void)
1946 return register_ftrace_command(&ftrace_mod_cmd
);
1948 device_initcall(ftrace_mod_cmd_init
);
1951 function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
)
1953 struct ftrace_func_probe
*entry
;
1954 struct hlist_head
*hhd
;
1955 struct hlist_node
*n
;
1959 key
= hash_long(ip
, FTRACE_HASH_BITS
);
1961 hhd
= &ftrace_func_hash
[key
];
1963 if (hlist_empty(hhd
))
1967 * Disable preemption for these calls to prevent a RCU grace
1968 * period. This syncs the hash iteration and freeing of items
1969 * on the hash. rcu_read_lock is too dangerous here.
1971 resched
= ftrace_preempt_disable();
1972 hlist_for_each_entry_rcu(entry
, n
, hhd
, node
) {
1973 if (entry
->ip
== ip
)
1974 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
1976 ftrace_preempt_enable(resched
);
1979 static struct ftrace_ops trace_probe_ops __read_mostly
=
1981 .func
= function_trace_probe_call
,
1984 static int ftrace_probe_registered
;
1986 static void __enable_ftrace_function_probe(void)
1990 if (ftrace_probe_registered
)
1993 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
1994 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
1998 /* Nothing registered? */
1999 if (i
== FTRACE_FUNC_HASHSIZE
)
2002 __register_ftrace_function(&trace_probe_ops
);
2004 ftrace_probe_registered
= 1;
2007 static void __disable_ftrace_function_probe(void)
2011 if (!ftrace_probe_registered
)
2014 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
2015 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
2020 /* no more funcs left */
2021 __unregister_ftrace_function(&trace_probe_ops
);
2023 ftrace_probe_registered
= 0;
2027 static void ftrace_free_entry_rcu(struct rcu_head
*rhp
)
2029 struct ftrace_func_probe
*entry
=
2030 container_of(rhp
, struct ftrace_func_probe
, rcu
);
2032 if (entry
->ops
->free
)
2033 entry
->ops
->free(&entry
->data
);
2039 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
2042 struct ftrace_func_probe
*entry
;
2043 struct ftrace_page
*pg
;
2044 struct dyn_ftrace
*rec
;
2050 type
= ftrace_setup_glob(glob
, strlen(glob
), &search
, ¬);
2051 len
= strlen(search
);
2053 /* we do not support '!' for function probes */
2057 mutex_lock(&ftrace_lock
);
2058 do_for_each_ftrace_rec(pg
, rec
) {
2060 if (rec
->flags
& FTRACE_FL_FAILED
)
2063 if (!ftrace_match_record(rec
, search
, len
, type
))
2066 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
2068 /* If we did not process any, then return error */
2079 * The caller might want to do something special
2080 * for each function we find. We call the callback
2081 * to give the caller an opportunity to do so.
2083 if (ops
->callback
) {
2084 if (ops
->callback(rec
->ip
, &entry
->data
) < 0) {
2085 /* caller does not like this func */
2092 entry
->ip
= rec
->ip
;
2094 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
2095 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
2097 } while_for_each_ftrace_rec();
2098 __enable_ftrace_function_probe();
2101 mutex_unlock(&ftrace_lock
);
2107 PROBE_TEST_FUNC
= 1,
2112 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
2113 void *data
, int flags
)
2115 struct ftrace_func_probe
*entry
;
2116 struct hlist_node
*n
, *tmp
;
2117 char str
[KSYM_SYMBOL_LEN
];
2118 int type
= MATCH_FULL
;
2122 if (glob
&& (strcmp(glob
, "*") || !strlen(glob
)))
2127 type
= ftrace_setup_glob(glob
, strlen(glob
), &search
, ¬);
2128 len
= strlen(search
);
2130 /* we do not support '!' for function probes */
2135 mutex_lock(&ftrace_lock
);
2136 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
2137 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
2139 hlist_for_each_entry_safe(entry
, n
, tmp
, hhd
, node
) {
2141 /* break up if statements for readability */
2142 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
2145 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
2148 /* do this last, since it is the most expensive */
2150 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
2152 if (!ftrace_match(str
, glob
, len
, type
))
2156 hlist_del(&entry
->node
);
2157 call_rcu(&entry
->rcu
, ftrace_free_entry_rcu
);
2160 __disable_ftrace_function_probe();
2161 mutex_unlock(&ftrace_lock
);
2165 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
2168 __unregister_ftrace_function_probe(glob
, ops
, data
,
2169 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
2173 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
2175 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
2178 void unregister_ftrace_function_probe_all(char *glob
)
2180 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
2183 static LIST_HEAD(ftrace_commands
);
2184 static DEFINE_MUTEX(ftrace_cmd_mutex
);
2186 int register_ftrace_command(struct ftrace_func_command
*cmd
)
2188 struct ftrace_func_command
*p
;
2191 mutex_lock(&ftrace_cmd_mutex
);
2192 list_for_each_entry(p
, &ftrace_commands
, list
) {
2193 if (strcmp(cmd
->name
, p
->name
) == 0) {
2198 list_add(&cmd
->list
, &ftrace_commands
);
2200 mutex_unlock(&ftrace_cmd_mutex
);
2205 int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
2207 struct ftrace_func_command
*p
, *n
;
2210 mutex_lock(&ftrace_cmd_mutex
);
2211 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
2212 if (strcmp(cmd
->name
, p
->name
) == 0) {
2214 list_del_init(&p
->list
);
2219 mutex_unlock(&ftrace_cmd_mutex
);
2224 static int ftrace_process_regex(char *buff
, int len
, int enable
)
2226 char *func
, *command
, *next
= buff
;
2227 struct ftrace_func_command
*p
;
2230 func
= strsep(&next
, ":");
2233 ftrace_match_records(func
, len
, enable
);
2239 command
= strsep(&next
, ":");
2241 mutex_lock(&ftrace_cmd_mutex
);
2242 list_for_each_entry(p
, &ftrace_commands
, list
) {
2243 if (strcmp(p
->name
, command
) == 0) {
2244 ret
= p
->func(func
, command
, next
, enable
);
2249 mutex_unlock(&ftrace_cmd_mutex
);
2255 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
2256 size_t cnt
, loff_t
*ppos
, int enable
)
2258 struct ftrace_iterator
*iter
;
2263 if (!cnt
|| cnt
< 0)
2266 mutex_lock(&ftrace_regex_lock
);
2268 if (file
->f_mode
& FMODE_READ
) {
2269 struct seq_file
*m
= file
->private_data
;
2272 iter
= file
->private_data
;
2275 iter
->flags
&= ~FTRACE_ITER_CONT
;
2276 iter
->buffer_idx
= 0;
2279 ret
= get_user(ch
, ubuf
++);
2285 if (!(iter
->flags
& ~FTRACE_ITER_CONT
)) {
2286 /* skip white space */
2287 while (cnt
&& isspace(ch
)) {
2288 ret
= get_user(ch
, ubuf
++);
2296 file
->f_pos
+= read
;
2301 iter
->buffer_idx
= 0;
2304 while (cnt
&& !isspace(ch
)) {
2305 if (iter
->buffer_idx
< FTRACE_BUFF_MAX
)
2306 iter
->buffer
[iter
->buffer_idx
++] = ch
;
2311 ret
= get_user(ch
, ubuf
++);
2320 iter
->buffer
[iter
->buffer_idx
] = 0;
2321 ret
= ftrace_process_regex(iter
->buffer
,
2322 iter
->buffer_idx
, enable
);
2325 iter
->buffer_idx
= 0;
2327 iter
->flags
|= FTRACE_ITER_CONT
;
2330 file
->f_pos
+= read
;
2334 mutex_unlock(&ftrace_regex_lock
);
2340 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
2341 size_t cnt
, loff_t
*ppos
)
2343 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
2347 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
2348 size_t cnt
, loff_t
*ppos
)
2350 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
2354 ftrace_set_regex(unsigned char *buf
, int len
, int reset
, int enable
)
2356 if (unlikely(ftrace_disabled
))
2359 mutex_lock(&ftrace_regex_lock
);
2361 ftrace_filter_reset(enable
);
2363 ftrace_match_records(buf
, len
, enable
);
2364 mutex_unlock(&ftrace_regex_lock
);
2368 * ftrace_set_filter - set a function to filter on in ftrace
2369 * @buf - the string that holds the function filter text.
2370 * @len - the length of the string.
2371 * @reset - non zero to reset all filters before applying this filter.
2373 * Filters denote which functions should be enabled when tracing is enabled.
2374 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
2376 void ftrace_set_filter(unsigned char *buf
, int len
, int reset
)
2378 ftrace_set_regex(buf
, len
, reset
, 1);
2382 * ftrace_set_notrace - set a function to not trace in ftrace
2383 * @buf - the string that holds the function notrace text.
2384 * @len - the length of the string.
2385 * @reset - non zero to reset all filters before applying this filter.
2387 * Notrace Filters denote which functions should not be enabled when tracing
2388 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
2391 void ftrace_set_notrace(unsigned char *buf
, int len
, int reset
)
2393 ftrace_set_regex(buf
, len
, reset
, 0);
2397 ftrace_regex_release(struct inode
*inode
, struct file
*file
, int enable
)
2399 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
2400 struct ftrace_iterator
*iter
;
2402 mutex_lock(&ftrace_regex_lock
);
2403 if (file
->f_mode
& FMODE_READ
) {
2406 seq_release(inode
, file
);
2408 iter
= file
->private_data
;
2410 if (iter
->buffer_idx
) {
2412 iter
->buffer
[iter
->buffer_idx
] = 0;
2413 ftrace_match_records(iter
->buffer
, iter
->buffer_idx
, enable
);
2416 mutex_lock(&ftrace_lock
);
2417 if (ftrace_start_up
&& ftrace_enabled
)
2418 ftrace_run_update_code(FTRACE_ENABLE_CALLS
);
2419 mutex_unlock(&ftrace_lock
);
2422 mutex_unlock(&ftrace_regex_lock
);
2427 ftrace_filter_release(struct inode
*inode
, struct file
*file
)
2429 return ftrace_regex_release(inode
, file
, 1);
2433 ftrace_notrace_release(struct inode
*inode
, struct file
*file
)
2435 return ftrace_regex_release(inode
, file
, 0);
2438 static const struct file_operations ftrace_avail_fops
= {
2439 .open
= ftrace_avail_open
,
2441 .llseek
= seq_lseek
,
2442 .release
= ftrace_avail_release
,
2445 static const struct file_operations ftrace_failures_fops
= {
2446 .open
= ftrace_failures_open
,
2448 .llseek
= seq_lseek
,
2449 .release
= ftrace_avail_release
,
2452 static const struct file_operations ftrace_filter_fops
= {
2453 .open
= ftrace_filter_open
,
2455 .write
= ftrace_filter_write
,
2456 .llseek
= ftrace_regex_lseek
,
2457 .release
= ftrace_filter_release
,
2460 static const struct file_operations ftrace_notrace_fops
= {
2461 .open
= ftrace_notrace_open
,
2463 .write
= ftrace_notrace_write
,
2464 .llseek
= ftrace_regex_lseek
,
2465 .release
= ftrace_notrace_release
,
2468 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2470 static DEFINE_MUTEX(graph_lock
);
2472 int ftrace_graph_count
;
2473 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
2476 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2478 unsigned long *array
= m
->private;
2483 if (index
>= ftrace_graph_count
)
2486 return &array
[index
];
2489 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
2493 mutex_lock(&graph_lock
);
2495 /* Nothing, tell g_show to print all functions are enabled */
2496 if (!ftrace_graph_count
&& !*pos
)
2499 p
= g_next(m
, p
, pos
);
2504 static void g_stop(struct seq_file
*m
, void *p
)
2506 mutex_unlock(&graph_lock
);
2509 static int g_show(struct seq_file
*m
, void *v
)
2511 unsigned long *ptr
= v
;
2512 char str
[KSYM_SYMBOL_LEN
];
2517 if (ptr
== (unsigned long *)1) {
2518 seq_printf(m
, "#### all functions enabled ####\n");
2522 kallsyms_lookup(*ptr
, NULL
, NULL
, NULL
, str
);
2524 seq_printf(m
, "%s\n", str
);
2529 static struct seq_operations ftrace_graph_seq_ops
= {
2537 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
2541 if (unlikely(ftrace_disabled
))
2544 mutex_lock(&graph_lock
);
2545 if ((file
->f_mode
& FMODE_WRITE
) &&
2546 !(file
->f_flags
& O_APPEND
)) {
2547 ftrace_graph_count
= 0;
2548 memset(ftrace_graph_funcs
, 0, sizeof(ftrace_graph_funcs
));
2551 if (file
->f_mode
& FMODE_READ
) {
2552 ret
= seq_open(file
, &ftrace_graph_seq_ops
);
2554 struct seq_file
*m
= file
->private_data
;
2555 m
->private = ftrace_graph_funcs
;
2558 file
->private_data
= ftrace_graph_funcs
;
2559 mutex_unlock(&graph_lock
);
2565 ftrace_set_func(unsigned long *array
, int *idx
, char *buffer
)
2567 struct dyn_ftrace
*rec
;
2568 struct ftrace_page
*pg
;
2576 if (ftrace_disabled
)
2580 type
= ftrace_setup_glob(buffer
, strlen(buffer
), &search
, ¬);
2584 search_len
= strlen(search
);
2586 mutex_lock(&ftrace_lock
);
2587 do_for_each_ftrace_rec(pg
, rec
) {
2589 if (*idx
>= FTRACE_GRAPH_MAX_FUNCS
)
2592 if (rec
->flags
& (FTRACE_FL_FAILED
| FTRACE_FL_FREE
))
2595 if (ftrace_match_record(rec
, search
, search_len
, type
)) {
2596 /* ensure it is not already in the array */
2598 for (i
= 0; i
< *idx
; i
++)
2599 if (array
[i
] == rec
->ip
) {
2604 array
[(*idx
)++] = rec
->ip
;
2608 } while_for_each_ftrace_rec();
2610 mutex_unlock(&ftrace_lock
);
2612 return found
? 0 : -EINVAL
;
2616 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
2617 size_t cnt
, loff_t
*ppos
)
2619 unsigned char buffer
[FTRACE_BUFF_MAX
+1];
2620 unsigned long *array
;
2626 if (!cnt
|| cnt
< 0)
2629 mutex_lock(&graph_lock
);
2631 if (ftrace_graph_count
>= FTRACE_GRAPH_MAX_FUNCS
) {
2636 if (file
->f_mode
& FMODE_READ
) {
2637 struct seq_file
*m
= file
->private_data
;
2640 array
= file
->private_data
;
2642 ret
= get_user(ch
, ubuf
++);
2648 /* skip white space */
2649 while (cnt
&& isspace(ch
)) {
2650 ret
= get_user(ch
, ubuf
++);
2663 while (cnt
&& !isspace(ch
)) {
2664 if (index
< FTRACE_BUFF_MAX
)
2665 buffer
[index
++] = ch
;
2670 ret
= get_user(ch
, ubuf
++);
2678 /* we allow only one expression at a time */
2679 ret
= ftrace_set_func(array
, &ftrace_graph_count
, buffer
);
2683 file
->f_pos
+= read
;
2687 mutex_unlock(&graph_lock
);
2692 static const struct file_operations ftrace_graph_fops
= {
2693 .open
= ftrace_graph_open
,
2695 .write
= ftrace_graph_write
,
2697 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2699 static __init
int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
)
2701 struct dentry
*entry
;
2703 entry
= debugfs_create_file("available_filter_functions", 0444,
2704 d_tracer
, NULL
, &ftrace_avail_fops
);
2706 pr_warning("Could not create debugfs "
2707 "'available_filter_functions' entry\n");
2709 entry
= debugfs_create_file("failures", 0444,
2710 d_tracer
, NULL
, &ftrace_failures_fops
);
2712 pr_warning("Could not create debugfs 'failures' entry\n");
2714 entry
= debugfs_create_file("set_ftrace_filter", 0644, d_tracer
,
2715 NULL
, &ftrace_filter_fops
);
2717 pr_warning("Could not create debugfs "
2718 "'set_ftrace_filter' entry\n");
2720 entry
= debugfs_create_file("set_ftrace_notrace", 0644, d_tracer
,
2721 NULL
, &ftrace_notrace_fops
);
2723 pr_warning("Could not create debugfs "
2724 "'set_ftrace_notrace' entry\n");
2726 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2727 entry
= debugfs_create_file("set_graph_function", 0444, d_tracer
,
2729 &ftrace_graph_fops
);
2731 pr_warning("Could not create debugfs "
2732 "'set_graph_function' entry\n");
2733 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2738 static int ftrace_convert_nops(struct module
*mod
,
2739 unsigned long *start
,
2744 unsigned long flags
;
2746 mutex_lock(&ftrace_lock
);
2749 addr
= ftrace_call_adjust(*p
++);
2751 * Some architecture linkers will pad between
2752 * the different mcount_loc sections of different
2753 * object files to satisfy alignments.
2754 * Skip any NULL pointers.
2758 ftrace_record_ip(addr
);
2761 /* disable interrupts to prevent kstop machine */
2762 local_irq_save(flags
);
2763 ftrace_update_code(mod
);
2764 local_irq_restore(flags
);
2765 mutex_unlock(&ftrace_lock
);
2770 void ftrace_init_module(struct module
*mod
,
2771 unsigned long *start
, unsigned long *end
)
2773 if (ftrace_disabled
|| start
== end
)
2775 ftrace_convert_nops(mod
, start
, end
);
2778 extern unsigned long __start_mcount_loc
[];
2779 extern unsigned long __stop_mcount_loc
[];
2781 void __init
ftrace_init(void)
2783 unsigned long count
, addr
, flags
;
2786 /* Keep the ftrace pointer to the stub */
2787 addr
= (unsigned long)ftrace_stub
;
2789 local_irq_save(flags
);
2790 ftrace_dyn_arch_init(&addr
);
2791 local_irq_restore(flags
);
2793 /* ftrace_dyn_arch_init places the return code in addr */
2797 count
= __stop_mcount_loc
- __start_mcount_loc
;
2799 ret
= ftrace_dyn_table_alloc(count
);
2803 last_ftrace_enabled
= ftrace_enabled
= 1;
2805 ret
= ftrace_convert_nops(NULL
,
2811 ftrace_disabled
= 1;
2816 static int __init
ftrace_nodyn_init(void)
2821 device_initcall(ftrace_nodyn_init
);
2823 static inline int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
) { return 0; }
2824 static inline void ftrace_startup_enable(int command
) { }
2825 /* Keep as macros so we do not need to define the commands */
2826 # define ftrace_startup(command) do { } while (0)
2827 # define ftrace_shutdown(command) do { } while (0)
2828 # define ftrace_startup_sysctl() do { } while (0)
2829 # define ftrace_shutdown_sysctl() do { } while (0)
2830 #endif /* CONFIG_DYNAMIC_FTRACE */
2833 ftrace_pid_read(struct file
*file
, char __user
*ubuf
,
2834 size_t cnt
, loff_t
*ppos
)
2839 if (ftrace_pid_trace
== ftrace_swapper_pid
)
2840 r
= sprintf(buf
, "swapper tasks\n");
2841 else if (ftrace_pid_trace
)
2842 r
= sprintf(buf
, "%u\n", pid_vnr(ftrace_pid_trace
));
2844 r
= sprintf(buf
, "no pid\n");
2846 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2849 static void clear_ftrace_swapper(void)
2851 struct task_struct
*p
;
2855 for_each_online_cpu(cpu
) {
2857 clear_tsk_trace_trace(p
);
2862 static void set_ftrace_swapper(void)
2864 struct task_struct
*p
;
2868 for_each_online_cpu(cpu
) {
2870 set_tsk_trace_trace(p
);
2875 static void clear_ftrace_pid(struct pid
*pid
)
2877 struct task_struct
*p
;
2880 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
2881 clear_tsk_trace_trace(p
);
2882 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
2888 static void set_ftrace_pid(struct pid
*pid
)
2890 struct task_struct
*p
;
2893 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
2894 set_tsk_trace_trace(p
);
2895 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
2899 static void clear_ftrace_pid_task(struct pid
**pid
)
2901 if (*pid
== ftrace_swapper_pid
)
2902 clear_ftrace_swapper();
2904 clear_ftrace_pid(*pid
);
2909 static void set_ftrace_pid_task(struct pid
*pid
)
2911 if (pid
== ftrace_swapper_pid
)
2912 set_ftrace_swapper();
2914 set_ftrace_pid(pid
);
2918 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
2919 size_t cnt
, loff_t
*ppos
)
2926 if (cnt
>= sizeof(buf
))
2929 if (copy_from_user(&buf
, ubuf
, cnt
))
2934 ret
= strict_strtol(buf
, 10, &val
);
2938 mutex_lock(&ftrace_lock
);
2940 /* disable pid tracing */
2941 if (!ftrace_pid_trace
)
2944 clear_ftrace_pid_task(&ftrace_pid_trace
);
2947 /* swapper task is special */
2949 pid
= ftrace_swapper_pid
;
2950 if (pid
== ftrace_pid_trace
)
2953 pid
= find_get_pid(val
);
2955 if (pid
== ftrace_pid_trace
) {
2961 if (ftrace_pid_trace
)
2962 clear_ftrace_pid_task(&ftrace_pid_trace
);
2967 ftrace_pid_trace
= pid
;
2969 set_ftrace_pid_task(ftrace_pid_trace
);
2972 /* update the function call */
2973 ftrace_update_pid_func();
2974 ftrace_startup_enable(0);
2977 mutex_unlock(&ftrace_lock
);
2982 static const struct file_operations ftrace_pid_fops
= {
2983 .read
= ftrace_pid_read
,
2984 .write
= ftrace_pid_write
,
2987 static __init
int ftrace_init_debugfs(void)
2989 struct dentry
*d_tracer
;
2990 struct dentry
*entry
;
2992 d_tracer
= tracing_init_dentry();
2996 ftrace_init_dyn_debugfs(d_tracer
);
2998 entry
= debugfs_create_file("set_ftrace_pid", 0644, d_tracer
,
2999 NULL
, &ftrace_pid_fops
);
3001 pr_warning("Could not create debugfs "
3002 "'set_ftrace_pid' entry\n");
3004 ftrace_profile_debugfs(d_tracer
);
3008 fs_initcall(ftrace_init_debugfs
);
3011 * ftrace_kill - kill ftrace
3013 * This function should be used by panic code. It stops ftrace
3014 * but in a not so nice way. If you need to simply kill ftrace
3015 * from a non-atomic section, use ftrace_kill.
3017 void ftrace_kill(void)
3019 ftrace_disabled
= 1;
3021 clear_ftrace_function();
3025 * register_ftrace_function - register a function for profiling
3026 * @ops - ops structure that holds the function for profiling.
3028 * Register a function to be called by all functions in the
3031 * Note: @ops->func and all the functions it calls must be labeled
3032 * with "notrace", otherwise it will go into a
3035 int register_ftrace_function(struct ftrace_ops
*ops
)
3039 if (unlikely(ftrace_disabled
))
3042 mutex_lock(&ftrace_lock
);
3044 ret
= __register_ftrace_function(ops
);
3047 mutex_unlock(&ftrace_lock
);
3052 * unregister_ftrace_function - unregister a function for profiling.
3053 * @ops - ops structure that holds the function to unregister
3055 * Unregister a function that was added to be called by ftrace profiling.
3057 int unregister_ftrace_function(struct ftrace_ops
*ops
)
3061 mutex_lock(&ftrace_lock
);
3062 ret
= __unregister_ftrace_function(ops
);
3064 mutex_unlock(&ftrace_lock
);
3070 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
3071 struct file
*file
, void __user
*buffer
, size_t *lenp
,
3076 if (unlikely(ftrace_disabled
))
3079 mutex_lock(&ftrace_lock
);
3081 ret
= proc_dointvec(table
, write
, file
, buffer
, lenp
, ppos
);
3083 if (ret
|| !write
|| (last_ftrace_enabled
== ftrace_enabled
))
3086 last_ftrace_enabled
= ftrace_enabled
;
3088 if (ftrace_enabled
) {
3090 ftrace_startup_sysctl();
3092 /* we are starting ftrace again */
3093 if (ftrace_list
!= &ftrace_list_end
) {
3094 if (ftrace_list
->next
== &ftrace_list_end
)
3095 ftrace_trace_function
= ftrace_list
->func
;
3097 ftrace_trace_function
= ftrace_list_func
;
3101 /* stopping ftrace calls (just send to ftrace_stub) */
3102 ftrace_trace_function
= ftrace_stub
;
3104 ftrace_shutdown_sysctl();
3108 mutex_unlock(&ftrace_lock
);
3112 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3114 static atomic_t ftrace_graph_active
;
3115 static struct notifier_block ftrace_suspend_notifier
;
3117 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
3122 /* The callbacks that hook a function */
3123 trace_func_graph_ret_t ftrace_graph_return
=
3124 (trace_func_graph_ret_t
)ftrace_stub
;
3125 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
3127 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
3128 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
3132 unsigned long flags
;
3133 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
3134 struct task_struct
*g
, *t
;
3136 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
3137 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
3138 * sizeof(struct ftrace_ret_stack
),
3140 if (!ret_stack_list
[i
]) {
3148 read_lock_irqsave(&tasklist_lock
, flags
);
3149 do_each_thread(g
, t
) {
3155 if (t
->ret_stack
== NULL
) {
3156 t
->curr_ret_stack
= -1;
3157 /* Make sure IRQs see the -1 first: */
3159 t
->ret_stack
= ret_stack_list
[start
++];
3160 atomic_set(&t
->tracing_graph_pause
, 0);
3161 atomic_set(&t
->trace_overrun
, 0);
3163 } while_each_thread(g
, t
);
3166 read_unlock_irqrestore(&tasklist_lock
, flags
);
3168 for (i
= start
; i
< end
; i
++)
3169 kfree(ret_stack_list
[i
]);
3174 ftrace_graph_probe_sched_switch(struct rq
*__rq
, struct task_struct
*prev
,
3175 struct task_struct
*next
)
3177 unsigned long long timestamp
;
3181 * Does the user want to count the time a function was asleep.
3182 * If so, do not update the time stamps.
3184 if (trace_flags
& TRACE_ITER_SLEEP_TIME
)
3187 timestamp
= trace_clock_local();
3189 prev
->ftrace_timestamp
= timestamp
;
3191 /* only process tasks that we timestamped */
3192 if (!next
->ftrace_timestamp
)
3196 * Update all the counters in next to make up for the
3197 * time next was sleeping.
3199 timestamp
-= next
->ftrace_timestamp
;
3201 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
3202 next
->ret_stack
[index
].calltime
+= timestamp
;
3205 /* Allocate a return stack for each task */
3206 static int start_graph_tracing(void)
3208 struct ftrace_ret_stack
**ret_stack_list
;
3211 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
3212 sizeof(struct ftrace_ret_stack
*),
3215 if (!ret_stack_list
)
3218 /* The cpu_boot init_task->ret_stack will never be freed */
3219 for_each_online_cpu(cpu
)
3220 ftrace_graph_init_task(idle_task(cpu
));
3223 ret
= alloc_retstack_tasklist(ret_stack_list
);
3224 } while (ret
== -EAGAIN
);
3227 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
);
3229 pr_info("ftrace_graph: Couldn't activate tracepoint"
3230 " probe to kernel_sched_switch\n");
3233 kfree(ret_stack_list
);
3238 * Hibernation protection.
3239 * The state of the current task is too much unstable during
3240 * suspend/restore to disk. We want to protect against that.
3243 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
3247 case PM_HIBERNATION_PREPARE
:
3248 pause_graph_tracing();
3251 case PM_POST_HIBERNATION
:
3252 unpause_graph_tracing();
3258 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
3259 trace_func_graph_ent_t entryfunc
)
3263 mutex_lock(&ftrace_lock
);
3265 /* we currently allow only one tracer registered at a time */
3266 if (atomic_read(&ftrace_graph_active
)) {
3271 ftrace_suspend_notifier
.notifier_call
= ftrace_suspend_notifier_call
;
3272 register_pm_notifier(&ftrace_suspend_notifier
);
3274 atomic_inc(&ftrace_graph_active
);
3275 ret
= start_graph_tracing();
3277 atomic_dec(&ftrace_graph_active
);
3281 ftrace_graph_return
= retfunc
;
3282 ftrace_graph_entry
= entryfunc
;
3284 ftrace_startup(FTRACE_START_FUNC_RET
);
3287 mutex_unlock(&ftrace_lock
);
3291 void unregister_ftrace_graph(void)
3293 mutex_lock(&ftrace_lock
);
3295 if (!unlikely(atomic_read(&ftrace_graph_active
)))
3298 atomic_dec(&ftrace_graph_active
);
3299 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
);
3300 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
3301 ftrace_graph_entry
= ftrace_graph_entry_stub
;
3302 ftrace_shutdown(FTRACE_STOP_FUNC_RET
);
3303 unregister_pm_notifier(&ftrace_suspend_notifier
);
3306 mutex_unlock(&ftrace_lock
);
3309 /* Allocate a return stack for newly created task */
3310 void ftrace_graph_init_task(struct task_struct
*t
)
3312 if (atomic_read(&ftrace_graph_active
)) {
3313 t
->ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
3314 * sizeof(struct ftrace_ret_stack
),
3318 t
->curr_ret_stack
= -1;
3319 atomic_set(&t
->tracing_graph_pause
, 0);
3320 atomic_set(&t
->trace_overrun
, 0);
3321 t
->ftrace_timestamp
= 0;
3323 t
->ret_stack
= NULL
;
3326 void ftrace_graph_exit_task(struct task_struct
*t
)
3328 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
3330 t
->ret_stack
= NULL
;
3331 /* NULL must become visible to IRQs before we free it: */
3337 void ftrace_graph_stop(void)