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/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>
36 #include <trace/events/sched.h>
38 #include <asm/setup.h>
40 #include "trace_output.h"
41 #include "trace_stat.h"
43 #define FTRACE_WARN_ON(cond) \
51 #define FTRACE_WARN_ON_ONCE(cond) \
54 if (WARN_ON_ONCE(___r)) \
59 /* hash bits for specific function selection */
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
65 #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
67 /* ftrace_enabled is a method to turn ftrace on or off */
68 int ftrace_enabled __read_mostly
;
69 static int last_ftrace_enabled
;
71 /* Quick disabling of function tracer. */
72 int function_trace_stop
;
74 /* List for set_ftrace_pid's pids. */
75 LIST_HEAD(ftrace_pids
);
77 struct list_head list
;
82 * ftrace_disabled is set when an anomaly is discovered.
83 * ftrace_disabled is much stronger than ftrace_enabled.
85 static int ftrace_disabled __read_mostly
;
87 static DEFINE_MUTEX(ftrace_lock
);
89 static struct ftrace_ops ftrace_list_end __read_mostly
= {
93 static struct ftrace_ops
*ftrace_global_list __read_mostly
= &ftrace_list_end
;
94 static struct ftrace_ops
*ftrace_control_list __read_mostly
= &ftrace_list_end
;
95 static struct ftrace_ops
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
96 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
97 static ftrace_func_t __ftrace_trace_function_delay __read_mostly
= ftrace_stub
;
98 ftrace_func_t __ftrace_trace_function __read_mostly
= ftrace_stub
;
99 ftrace_func_t ftrace_pid_function __read_mostly
= ftrace_stub
;
100 static struct ftrace_ops global_ops
;
101 static struct ftrace_ops control_ops
;
104 ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
);
107 * Traverse the ftrace_global_list, invoking all entries. The reason that we
108 * can use rcu_dereference_raw() is that elements removed from this list
109 * are simply leaked, so there is no need to interact with a grace-period
110 * mechanism. The rcu_dereference_raw() calls are needed to handle
111 * concurrent insertions into the ftrace_global_list.
113 * Silly Alpha and silly pointer-speculation compiler optimizations!
115 static void ftrace_global_list_func(unsigned long ip
,
116 unsigned long parent_ip
)
118 struct ftrace_ops
*op
;
120 if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT
)))
123 trace_recursion_set(TRACE_GLOBAL_BIT
);
124 op
= rcu_dereference_raw(ftrace_global_list
); /*see above*/
125 while (op
!= &ftrace_list_end
) {
126 op
->func(ip
, parent_ip
);
127 op
= rcu_dereference_raw(op
->next
); /*see above*/
129 trace_recursion_clear(TRACE_GLOBAL_BIT
);
132 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
)
134 if (!test_tsk_trace_trace(current
))
137 ftrace_pid_function(ip
, parent_ip
);
140 static void set_ftrace_pid_function(ftrace_func_t func
)
142 /* do not set ftrace_pid_function to itself! */
143 if (func
!= ftrace_pid_func
)
144 ftrace_pid_function
= func
;
148 * clear_ftrace_function - reset the ftrace function
150 * This NULLs the ftrace function and in essence stops
151 * tracing. There may be lag
153 void clear_ftrace_function(void)
155 ftrace_trace_function
= ftrace_stub
;
156 __ftrace_trace_function
= ftrace_stub
;
157 __ftrace_trace_function_delay
= ftrace_stub
;
158 ftrace_pid_function
= ftrace_stub
;
161 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
163 * For those archs that do not test ftrace_trace_stop in their
164 * mcount call site, we need to do it from C.
166 static void ftrace_test_stop_func(unsigned long ip
, unsigned long parent_ip
)
168 if (function_trace_stop
)
171 __ftrace_trace_function(ip
, parent_ip
);
175 static void control_ops_disable_all(struct ftrace_ops
*ops
)
179 for_each_possible_cpu(cpu
)
180 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
183 static int control_ops_alloc(struct ftrace_ops
*ops
)
185 int __percpu
*disabled
;
187 disabled
= alloc_percpu(int);
191 ops
->disabled
= disabled
;
192 control_ops_disable_all(ops
);
196 static void control_ops_free(struct ftrace_ops
*ops
)
198 free_percpu(ops
->disabled
);
201 static void update_global_ops(void)
206 * If there's only one function registered, then call that
207 * function directly. Otherwise, we need to iterate over the
208 * registered callers.
210 if (ftrace_global_list
== &ftrace_list_end
||
211 ftrace_global_list
->next
== &ftrace_list_end
)
212 func
= ftrace_global_list
->func
;
214 func
= ftrace_global_list_func
;
216 /* If we filter on pids, update to use the pid function */
217 if (!list_empty(&ftrace_pids
)) {
218 set_ftrace_pid_function(func
);
219 func
= ftrace_pid_func
;
222 global_ops
.func
= func
;
225 static void update_ftrace_function(void)
232 * If we are at the end of the list and this ops is
233 * not dynamic, then have the mcount trampoline call
234 * the function directly
236 if (ftrace_ops_list
== &ftrace_list_end
||
237 (ftrace_ops_list
->next
== &ftrace_list_end
&&
238 !(ftrace_ops_list
->flags
& FTRACE_OPS_FL_DYNAMIC
)))
239 func
= ftrace_ops_list
->func
;
241 func
= ftrace_ops_list_func
;
243 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
244 ftrace_trace_function
= func
;
246 #ifdef CONFIG_DYNAMIC_FTRACE
247 /* do not update till all functions have been modified */
248 __ftrace_trace_function_delay
= func
;
250 __ftrace_trace_function
= func
;
252 ftrace_trace_function
=
253 (func
== ftrace_stub
) ? func
: ftrace_test_stop_func
;
257 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
261 * We are entering ops into the list but another
262 * CPU might be walking that list. We need to make sure
263 * the ops->next pointer is valid before another CPU sees
264 * the ops pointer included into the list.
266 rcu_assign_pointer(*list
, ops
);
269 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
271 struct ftrace_ops
**p
;
274 * If we are removing the last function, then simply point
275 * to the ftrace_stub.
277 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
278 *list
= &ftrace_list_end
;
282 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
293 static void add_ftrace_list_ops(struct ftrace_ops
**list
,
294 struct ftrace_ops
*main_ops
,
295 struct ftrace_ops
*ops
)
297 int first
= *list
== &ftrace_list_end
;
298 add_ftrace_ops(list
, ops
);
300 add_ftrace_ops(&ftrace_ops_list
, main_ops
);
303 static int remove_ftrace_list_ops(struct ftrace_ops
**list
,
304 struct ftrace_ops
*main_ops
,
305 struct ftrace_ops
*ops
)
307 int ret
= remove_ftrace_ops(list
, ops
);
308 if (!ret
&& *list
== &ftrace_list_end
)
309 ret
= remove_ftrace_ops(&ftrace_ops_list
, main_ops
);
313 static int __register_ftrace_function(struct ftrace_ops
*ops
)
318 if (FTRACE_WARN_ON(ops
== &global_ops
))
321 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
324 /* We don't support both control and global flags set. */
325 if ((ops
->flags
& FL_GLOBAL_CONTROL_MASK
) == FL_GLOBAL_CONTROL_MASK
)
328 if (!core_kernel_data((unsigned long)ops
))
329 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
331 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
332 add_ftrace_list_ops(&ftrace_global_list
, &global_ops
, ops
);
333 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
334 } else if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
335 if (control_ops_alloc(ops
))
337 add_ftrace_list_ops(&ftrace_control_list
, &control_ops
, ops
);
339 add_ftrace_ops(&ftrace_ops_list
, ops
);
342 update_ftrace_function();
347 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
354 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
357 if (FTRACE_WARN_ON(ops
== &global_ops
))
360 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
361 ret
= remove_ftrace_list_ops(&ftrace_global_list
,
364 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
365 } else if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
366 ret
= remove_ftrace_list_ops(&ftrace_control_list
,
370 * The ftrace_ops is now removed from the list,
371 * so there'll be no new users. We must ensure
372 * all current users are done before we free
376 control_ops_free(ops
);
379 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
385 update_ftrace_function();
388 * Dynamic ops may be freed, we must make sure that all
389 * callers are done before leaving this function.
391 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
)
397 static void ftrace_update_pid_func(void)
399 /* Only do something if we are tracing something */
400 if (ftrace_trace_function
== ftrace_stub
)
403 update_ftrace_function();
406 #ifdef CONFIG_FUNCTION_PROFILER
407 struct ftrace_profile
{
408 struct hlist_node node
;
410 unsigned long counter
;
411 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
412 unsigned long long time
;
413 unsigned long long time_squared
;
417 struct ftrace_profile_page
{
418 struct ftrace_profile_page
*next
;
420 struct ftrace_profile records
[];
423 struct ftrace_profile_stat
{
425 struct hlist_head
*hash
;
426 struct ftrace_profile_page
*pages
;
427 struct ftrace_profile_page
*start
;
428 struct tracer_stat stat
;
431 #define PROFILE_RECORDS_SIZE \
432 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
434 #define PROFILES_PER_PAGE \
435 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
437 static int ftrace_profile_bits __read_mostly
;
438 static int ftrace_profile_enabled __read_mostly
;
440 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
441 static DEFINE_MUTEX(ftrace_profile_lock
);
443 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
445 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
448 function_stat_next(void *v
, int idx
)
450 struct ftrace_profile
*rec
= v
;
451 struct ftrace_profile_page
*pg
;
453 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
459 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
463 rec
= &pg
->records
[0];
471 static void *function_stat_start(struct tracer_stat
*trace
)
473 struct ftrace_profile_stat
*stat
=
474 container_of(trace
, struct ftrace_profile_stat
, stat
);
476 if (!stat
|| !stat
->start
)
479 return function_stat_next(&stat
->start
->records
[0], 0);
482 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
483 /* function graph compares on total time */
484 static int function_stat_cmp(void *p1
, void *p2
)
486 struct ftrace_profile
*a
= p1
;
487 struct ftrace_profile
*b
= p2
;
489 if (a
->time
< b
->time
)
491 if (a
->time
> b
->time
)
497 /* not function graph compares against hits */
498 static int function_stat_cmp(void *p1
, void *p2
)
500 struct ftrace_profile
*a
= p1
;
501 struct ftrace_profile
*b
= p2
;
503 if (a
->counter
< b
->counter
)
505 if (a
->counter
> b
->counter
)
512 static int function_stat_headers(struct seq_file
*m
)
514 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
515 seq_printf(m
, " Function "
518 "--- ---- --- ---\n");
520 seq_printf(m
, " Function Hit\n"
526 static int function_stat_show(struct seq_file
*m
, void *v
)
528 struct ftrace_profile
*rec
= v
;
529 char str
[KSYM_SYMBOL_LEN
];
531 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
532 static struct trace_seq s
;
533 unsigned long long avg
;
534 unsigned long long stddev
;
536 mutex_lock(&ftrace_profile_lock
);
538 /* we raced with function_profile_reset() */
539 if (unlikely(rec
->counter
== 0)) {
544 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
545 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
547 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
550 do_div(avg
, rec
->counter
);
552 /* Sample standard deviation (s^2) */
553 if (rec
->counter
<= 1)
556 stddev
= rec
->time_squared
- rec
->counter
* avg
* avg
;
558 * Divide only 1000 for ns^2 -> us^2 conversion.
559 * trace_print_graph_duration will divide 1000 again.
561 do_div(stddev
, (rec
->counter
- 1) * 1000);
565 trace_print_graph_duration(rec
->time
, &s
);
566 trace_seq_puts(&s
, " ");
567 trace_print_graph_duration(avg
, &s
);
568 trace_seq_puts(&s
, " ");
569 trace_print_graph_duration(stddev
, &s
);
570 trace_print_seq(m
, &s
);
574 mutex_unlock(&ftrace_profile_lock
);
579 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
581 struct ftrace_profile_page
*pg
;
583 pg
= stat
->pages
= stat
->start
;
586 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
591 memset(stat
->hash
, 0,
592 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
595 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
597 struct ftrace_profile_page
*pg
;
602 /* If we already allocated, do nothing */
606 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
610 #ifdef CONFIG_DYNAMIC_FTRACE
611 functions
= ftrace_update_tot_cnt
;
614 * We do not know the number of functions that exist because
615 * dynamic tracing is what counts them. With past experience
616 * we have around 20K functions. That should be more than enough.
617 * It is highly unlikely we will execute every function in
623 pg
= stat
->start
= stat
->pages
;
625 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
627 for (i
= 0; i
< pages
; i
++) {
628 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
639 unsigned long tmp
= (unsigned long)pg
;
645 free_page((unsigned long)stat
->pages
);
652 static int ftrace_profile_init_cpu(int cpu
)
654 struct ftrace_profile_stat
*stat
;
657 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
660 /* If the profile is already created, simply reset it */
661 ftrace_profile_reset(stat
);
666 * We are profiling all functions, but usually only a few thousand
667 * functions are hit. We'll make a hash of 1024 items.
669 size
= FTRACE_PROFILE_HASH_SIZE
;
671 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
676 if (!ftrace_profile_bits
) {
679 for (; size
; size
>>= 1)
680 ftrace_profile_bits
++;
683 /* Preallocate the function profiling pages */
684 if (ftrace_profile_pages_init(stat
) < 0) {
693 static int ftrace_profile_init(void)
698 for_each_online_cpu(cpu
) {
699 ret
= ftrace_profile_init_cpu(cpu
);
707 /* interrupts must be disabled */
708 static struct ftrace_profile
*
709 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
711 struct ftrace_profile
*rec
;
712 struct hlist_head
*hhd
;
713 struct hlist_node
*n
;
716 key
= hash_long(ip
, ftrace_profile_bits
);
717 hhd
= &stat
->hash
[key
];
719 if (hlist_empty(hhd
))
722 hlist_for_each_entry_rcu(rec
, n
, hhd
, node
) {
730 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
731 struct ftrace_profile
*rec
)
735 key
= hash_long(rec
->ip
, ftrace_profile_bits
);
736 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
740 * The memory is already allocated, this simply finds a new record to use.
742 static struct ftrace_profile
*
743 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
745 struct ftrace_profile
*rec
= NULL
;
747 /* prevent recursion (from NMIs) */
748 if (atomic_inc_return(&stat
->disabled
) != 1)
752 * Try to find the function again since an NMI
753 * could have added it
755 rec
= ftrace_find_profiled_func(stat
, ip
);
759 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
760 if (!stat
->pages
->next
)
762 stat
->pages
= stat
->pages
->next
;
765 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
767 ftrace_add_profile(stat
, rec
);
770 atomic_dec(&stat
->disabled
);
776 function_profile_call(unsigned long ip
, unsigned long parent_ip
)
778 struct ftrace_profile_stat
*stat
;
779 struct ftrace_profile
*rec
;
782 if (!ftrace_profile_enabled
)
785 local_irq_save(flags
);
787 stat
= &__get_cpu_var(ftrace_profile_stats
);
788 if (!stat
->hash
|| !ftrace_profile_enabled
)
791 rec
= ftrace_find_profiled_func(stat
, ip
);
793 rec
= ftrace_profile_alloc(stat
, ip
);
800 local_irq_restore(flags
);
803 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
804 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
806 function_profile_call(trace
->func
, 0);
810 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
812 struct ftrace_profile_stat
*stat
;
813 unsigned long long calltime
;
814 struct ftrace_profile
*rec
;
817 local_irq_save(flags
);
818 stat
= &__get_cpu_var(ftrace_profile_stats
);
819 if (!stat
->hash
|| !ftrace_profile_enabled
)
822 /* If the calltime was zero'd ignore it */
823 if (!trace
->calltime
)
826 calltime
= trace
->rettime
- trace
->calltime
;
828 if (!(trace_flags
& TRACE_ITER_GRAPH_TIME
)) {
831 index
= trace
->depth
;
833 /* Append this call time to the parent time to subtract */
835 current
->ret_stack
[index
- 1].subtime
+= calltime
;
837 if (current
->ret_stack
[index
].subtime
< calltime
)
838 calltime
-= current
->ret_stack
[index
].subtime
;
843 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
845 rec
->time
+= calltime
;
846 rec
->time_squared
+= calltime
* calltime
;
850 local_irq_restore(flags
);
853 static int register_ftrace_profiler(void)
855 return register_ftrace_graph(&profile_graph_return
,
856 &profile_graph_entry
);
859 static void unregister_ftrace_profiler(void)
861 unregister_ftrace_graph();
864 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
865 .func
= function_profile_call
,
868 static int register_ftrace_profiler(void)
870 return register_ftrace_function(&ftrace_profile_ops
);
873 static void unregister_ftrace_profiler(void)
875 unregister_ftrace_function(&ftrace_profile_ops
);
877 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
880 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
881 size_t cnt
, loff_t
*ppos
)
886 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
892 mutex_lock(&ftrace_profile_lock
);
893 if (ftrace_profile_enabled
^ val
) {
895 ret
= ftrace_profile_init();
901 ret
= register_ftrace_profiler();
906 ftrace_profile_enabled
= 1;
908 ftrace_profile_enabled
= 0;
910 * unregister_ftrace_profiler calls stop_machine
911 * so this acts like an synchronize_sched.
913 unregister_ftrace_profiler();
917 mutex_unlock(&ftrace_profile_lock
);
925 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
926 size_t cnt
, loff_t
*ppos
)
928 char buf
[64]; /* big enough to hold a number */
931 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
932 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
935 static const struct file_operations ftrace_profile_fops
= {
936 .open
= tracing_open_generic
,
937 .read
= ftrace_profile_read
,
938 .write
= ftrace_profile_write
,
939 .llseek
= default_llseek
,
942 /* used to initialize the real stat files */
943 static struct tracer_stat function_stats __initdata
= {
945 .stat_start
= function_stat_start
,
946 .stat_next
= function_stat_next
,
947 .stat_cmp
= function_stat_cmp
,
948 .stat_headers
= function_stat_headers
,
949 .stat_show
= function_stat_show
952 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
954 struct ftrace_profile_stat
*stat
;
955 struct dentry
*entry
;
960 for_each_possible_cpu(cpu
) {
961 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
963 /* allocate enough for function name + cpu number */
964 name
= kmalloc(32, GFP_KERNEL
);
967 * The files created are permanent, if something happens
968 * we still do not free memory.
971 "Could not allocate stat file for cpu %d\n",
975 stat
->stat
= function_stats
;
976 snprintf(name
, 32, "function%d", cpu
);
977 stat
->stat
.name
= name
;
978 ret
= register_stat_tracer(&stat
->stat
);
981 "Could not register function stat for cpu %d\n",
988 entry
= debugfs_create_file("function_profile_enabled", 0644,
989 d_tracer
, NULL
, &ftrace_profile_fops
);
991 pr_warning("Could not create debugfs "
992 "'function_profile_enabled' entry\n");
995 #else /* CONFIG_FUNCTION_PROFILER */
996 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
999 #endif /* CONFIG_FUNCTION_PROFILER */
1001 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1003 #ifdef CONFIG_DYNAMIC_FTRACE
1005 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1006 # error Dynamic ftrace depends on MCOUNT_RECORD
1009 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1011 struct ftrace_func_probe
{
1012 struct hlist_node node
;
1013 struct ftrace_probe_ops
*ops
;
1014 unsigned long flags
;
1017 struct rcu_head rcu
;
1020 struct ftrace_func_entry
{
1021 struct hlist_node hlist
;
1025 struct ftrace_hash
{
1026 unsigned long size_bits
;
1027 struct hlist_head
*buckets
;
1028 unsigned long count
;
1029 struct rcu_head rcu
;
1033 * We make these constant because no one should touch them,
1034 * but they are used as the default "empty hash", to avoid allocating
1035 * it all the time. These are in a read only section such that if
1036 * anyone does try to modify it, it will cause an exception.
1038 static const struct hlist_head empty_buckets
[1];
1039 static const struct ftrace_hash empty_hash
= {
1040 .buckets
= (struct hlist_head
*)empty_buckets
,
1042 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1044 static struct ftrace_ops global_ops
= {
1045 .func
= ftrace_stub
,
1046 .notrace_hash
= EMPTY_HASH
,
1047 .filter_hash
= EMPTY_HASH
,
1050 static DEFINE_MUTEX(ftrace_regex_lock
);
1052 struct ftrace_page
{
1053 struct ftrace_page
*next
;
1054 struct dyn_ftrace
*records
;
1059 static struct ftrace_page
*ftrace_new_pgs
;
1061 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1062 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1064 /* estimate from running different kernels */
1065 #define NR_TO_INIT 10000
1067 static struct ftrace_page
*ftrace_pages_start
;
1068 static struct ftrace_page
*ftrace_pages
;
1070 static bool ftrace_hash_empty(struct ftrace_hash
*hash
)
1072 return !hash
|| !hash
->count
;
1075 static struct ftrace_func_entry
*
1076 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1079 struct ftrace_func_entry
*entry
;
1080 struct hlist_head
*hhd
;
1081 struct hlist_node
*n
;
1083 if (ftrace_hash_empty(hash
))
1086 if (hash
->size_bits
> 0)
1087 key
= hash_long(ip
, hash
->size_bits
);
1091 hhd
= &hash
->buckets
[key
];
1093 hlist_for_each_entry_rcu(entry
, n
, hhd
, hlist
) {
1094 if (entry
->ip
== ip
)
1100 static void __add_hash_entry(struct ftrace_hash
*hash
,
1101 struct ftrace_func_entry
*entry
)
1103 struct hlist_head
*hhd
;
1106 if (hash
->size_bits
)
1107 key
= hash_long(entry
->ip
, hash
->size_bits
);
1111 hhd
= &hash
->buckets
[key
];
1112 hlist_add_head(&entry
->hlist
, hhd
);
1116 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1118 struct ftrace_func_entry
*entry
;
1120 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1125 __add_hash_entry(hash
, entry
);
1131 free_hash_entry(struct ftrace_hash
*hash
,
1132 struct ftrace_func_entry
*entry
)
1134 hlist_del(&entry
->hlist
);
1140 remove_hash_entry(struct ftrace_hash
*hash
,
1141 struct ftrace_func_entry
*entry
)
1143 hlist_del(&entry
->hlist
);
1147 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1149 struct hlist_head
*hhd
;
1150 struct hlist_node
*tp
, *tn
;
1151 struct ftrace_func_entry
*entry
;
1152 int size
= 1 << hash
->size_bits
;
1158 for (i
= 0; i
< size
; i
++) {
1159 hhd
= &hash
->buckets
[i
];
1160 hlist_for_each_entry_safe(entry
, tp
, tn
, hhd
, hlist
)
1161 free_hash_entry(hash
, entry
);
1163 FTRACE_WARN_ON(hash
->count
);
1166 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1168 if (!hash
|| hash
== EMPTY_HASH
)
1170 ftrace_hash_clear(hash
);
1171 kfree(hash
->buckets
);
1175 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1177 struct ftrace_hash
*hash
;
1179 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1180 free_ftrace_hash(hash
);
1183 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1185 if (!hash
|| hash
== EMPTY_HASH
)
1187 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1190 void ftrace_free_filter(struct ftrace_ops
*ops
)
1192 free_ftrace_hash(ops
->filter_hash
);
1193 free_ftrace_hash(ops
->notrace_hash
);
1196 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1198 struct ftrace_hash
*hash
;
1201 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1205 size
= 1 << size_bits
;
1206 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1208 if (!hash
->buckets
) {
1213 hash
->size_bits
= size_bits
;
1218 static struct ftrace_hash
*
1219 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1221 struct ftrace_func_entry
*entry
;
1222 struct ftrace_hash
*new_hash
;
1223 struct hlist_node
*tp
;
1228 new_hash
= alloc_ftrace_hash(size_bits
);
1233 if (ftrace_hash_empty(hash
))
1236 size
= 1 << hash
->size_bits
;
1237 for (i
= 0; i
< size
; i
++) {
1238 hlist_for_each_entry(entry
, tp
, &hash
->buckets
[i
], hlist
) {
1239 ret
= add_hash_entry(new_hash
, entry
->ip
);
1245 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1250 free_ftrace_hash(new_hash
);
1255 ftrace_hash_rec_disable(struct ftrace_ops
*ops
, int filter_hash
);
1257 ftrace_hash_rec_enable(struct ftrace_ops
*ops
, int filter_hash
);
1260 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1261 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1263 struct ftrace_func_entry
*entry
;
1264 struct hlist_node
*tp
, *tn
;
1265 struct hlist_head
*hhd
;
1266 struct ftrace_hash
*old_hash
;
1267 struct ftrace_hash
*new_hash
;
1269 int size
= src
->count
;
1275 * Remove the current set, update the hash and add
1278 ftrace_hash_rec_disable(ops
, enable
);
1281 * If the new source is empty, just free dst and assign it
1285 free_ftrace_hash_rcu(*dst
);
1286 rcu_assign_pointer(*dst
, EMPTY_HASH
);
1287 /* still need to update the function records */
1293 * Make the hash size about 1/2 the # found
1295 for (size
/= 2; size
; size
>>= 1)
1298 /* Don't allocate too much */
1299 if (bits
> FTRACE_HASH_MAX_BITS
)
1300 bits
= FTRACE_HASH_MAX_BITS
;
1303 new_hash
= alloc_ftrace_hash(bits
);
1307 size
= 1 << src
->size_bits
;
1308 for (i
= 0; i
< size
; i
++) {
1309 hhd
= &src
->buckets
[i
];
1310 hlist_for_each_entry_safe(entry
, tp
, tn
, hhd
, hlist
) {
1312 key
= hash_long(entry
->ip
, bits
);
1315 remove_hash_entry(src
, entry
);
1316 __add_hash_entry(new_hash
, entry
);
1321 rcu_assign_pointer(*dst
, new_hash
);
1322 free_ftrace_hash_rcu(old_hash
);
1327 * Enable regardless of ret:
1328 * On success, we enable the new hash.
1329 * On failure, we re-enable the original hash.
1331 ftrace_hash_rec_enable(ops
, enable
);
1337 * Test the hashes for this ops to see if we want to call
1338 * the ops->func or not.
1340 * It's a match if the ip is in the ops->filter_hash or
1341 * the filter_hash does not exist or is empty,
1343 * the ip is not in the ops->notrace_hash.
1345 * This needs to be called with preemption disabled as
1346 * the hashes are freed with call_rcu_sched().
1349 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
)
1351 struct ftrace_hash
*filter_hash
;
1352 struct ftrace_hash
*notrace_hash
;
1355 filter_hash
= rcu_dereference_raw(ops
->filter_hash
);
1356 notrace_hash
= rcu_dereference_raw(ops
->notrace_hash
);
1358 if ((ftrace_hash_empty(filter_hash
) ||
1359 ftrace_lookup_ip(filter_hash
, ip
)) &&
1360 (ftrace_hash_empty(notrace_hash
) ||
1361 !ftrace_lookup_ip(notrace_hash
, ip
)))
1370 * This is a double for. Do not use 'break' to break out of the loop,
1371 * you must use a goto.
1373 #define do_for_each_ftrace_rec(pg, rec) \
1374 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1376 for (_____i = 0; _____i < pg->index; _____i++) { \
1377 rec = &pg->records[_____i];
1379 #define while_for_each_ftrace_rec() \
1384 static int ftrace_cmp_recs(const void *a
, const void *b
)
1386 const struct dyn_ftrace
*key
= a
;
1387 const struct dyn_ftrace
*rec
= b
;
1389 if (key
->flags
< rec
->ip
)
1391 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1396 static int ftrace_location_range(unsigned long start
, unsigned long end
)
1398 struct ftrace_page
*pg
;
1399 struct dyn_ftrace
*rec
;
1400 struct dyn_ftrace key
;
1403 key
.flags
= end
; /* overload flags, as it is unsigned long */
1405 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1406 if (end
< pg
->records
[0].ip
||
1407 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1409 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1410 sizeof(struct dyn_ftrace
),
1420 * ftrace_location - return true if the ip giving is a traced location
1421 * @ip: the instruction pointer to check
1423 * Returns 1 if @ip given is a pointer to a ftrace location.
1424 * That is, the instruction that is either a NOP or call to
1425 * the function tracer. It checks the ftrace internal tables to
1426 * determine if the address belongs or not.
1428 int ftrace_location(unsigned long ip
)
1430 return ftrace_location_range(ip
, ip
);
1434 * ftrace_text_reserved - return true if range contains an ftrace location
1435 * @start: start of range to search
1436 * @end: end of range to search (inclusive). @end points to the last byte to check.
1438 * Returns 1 if @start and @end contains a ftrace location.
1439 * That is, the instruction that is either a NOP or call to
1440 * the function tracer. It checks the ftrace internal tables to
1441 * determine if the address belongs or not.
1443 int ftrace_text_reserved(void *start
, void *end
)
1445 return ftrace_location_range((unsigned long)start
,
1446 (unsigned long)end
);
1449 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1453 struct ftrace_hash
*hash
;
1454 struct ftrace_hash
*other_hash
;
1455 struct ftrace_page
*pg
;
1456 struct dyn_ftrace
*rec
;
1460 /* Only update if the ops has been registered */
1461 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1465 * In the filter_hash case:
1466 * If the count is zero, we update all records.
1467 * Otherwise we just update the items in the hash.
1469 * In the notrace_hash case:
1470 * We enable the update in the hash.
1471 * As disabling notrace means enabling the tracing,
1472 * and enabling notrace means disabling, the inc variable
1476 hash
= ops
->filter_hash
;
1477 other_hash
= ops
->notrace_hash
;
1478 if (ftrace_hash_empty(hash
))
1482 hash
= ops
->notrace_hash
;
1483 other_hash
= ops
->filter_hash
;
1485 * If the notrace hash has no items,
1486 * then there's nothing to do.
1488 if (ftrace_hash_empty(hash
))
1492 do_for_each_ftrace_rec(pg
, rec
) {
1493 int in_other_hash
= 0;
1499 * Only the filter_hash affects all records.
1500 * Update if the record is not in the notrace hash.
1502 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1505 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1506 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1511 if (filter_hash
&& in_hash
&& !in_other_hash
)
1513 else if (!filter_hash
&& in_hash
&&
1514 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1522 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == FTRACE_REF_MAX
))
1525 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == 0))
1530 /* Shortcut, if we handled all records, we are done. */
1531 if (!all
&& count
== hash
->count
)
1533 } while_for_each_ftrace_rec();
1536 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1539 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1542 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1545 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1548 static void print_ip_ins(const char *fmt
, unsigned char *p
)
1552 printk(KERN_CONT
"%s", fmt
);
1554 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1555 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1559 * ftrace_bug - report and shutdown function tracer
1560 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1561 * @ip: The address that failed
1563 * The arch code that enables or disables the function tracing
1564 * can call ftrace_bug() when it has detected a problem in
1565 * modifying the code. @failed should be one of either:
1566 * EFAULT - if the problem happens on reading the @ip address
1567 * EINVAL - if what is read at @ip is not what was expected
1568 * EPERM - if the problem happens on writting to the @ip address
1570 void ftrace_bug(int failed
, unsigned long ip
)
1574 FTRACE_WARN_ON_ONCE(1);
1575 pr_info("ftrace faulted on modifying ");
1579 FTRACE_WARN_ON_ONCE(1);
1580 pr_info("ftrace failed to modify ");
1582 print_ip_ins(" actual: ", (unsigned char *)ip
);
1583 printk(KERN_CONT
"\n");
1586 FTRACE_WARN_ON_ONCE(1);
1587 pr_info("ftrace faulted on writing ");
1591 FTRACE_WARN_ON_ONCE(1);
1592 pr_info("ftrace faulted on unknown error ");
1597 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
1599 unsigned long flag
= 0UL;
1602 * If we are updating calls:
1604 * If the record has a ref count, then we need to enable it
1605 * because someone is using it.
1607 * Otherwise we make sure its disabled.
1609 * If we are disabling calls, then disable all records that
1612 if (enable
&& (rec
->flags
& ~FTRACE_FL_MASK
))
1613 flag
= FTRACE_FL_ENABLED
;
1615 /* If the state of this record hasn't changed, then do nothing */
1616 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
1617 return FTRACE_UPDATE_IGNORE
;
1621 rec
->flags
|= FTRACE_FL_ENABLED
;
1622 return FTRACE_UPDATE_MAKE_CALL
;
1626 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1628 return FTRACE_UPDATE_MAKE_NOP
;
1632 * ftrace_update_record, set a record that now is tracing or not
1633 * @rec: the record to update
1634 * @enable: set to 1 if the record is tracing, zero to force disable
1636 * The records that represent all functions that can be traced need
1637 * to be updated when tracing has been enabled.
1639 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
1641 return ftrace_check_record(rec
, enable
, 1);
1645 * ftrace_test_record, check if the record has been enabled or not
1646 * @rec: the record to test
1647 * @enable: set to 1 to check if enabled, 0 if it is disabled
1649 * The arch code may need to test if a record is already set to
1650 * tracing to determine how to modify the function code that it
1653 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
1655 return ftrace_check_record(rec
, enable
, 0);
1659 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
1661 unsigned long ftrace_addr
;
1664 ftrace_addr
= (unsigned long)FTRACE_ADDR
;
1666 ret
= ftrace_update_record(rec
, enable
);
1669 case FTRACE_UPDATE_IGNORE
:
1672 case FTRACE_UPDATE_MAKE_CALL
:
1673 return ftrace_make_call(rec
, ftrace_addr
);
1675 case FTRACE_UPDATE_MAKE_NOP
:
1676 return ftrace_make_nop(NULL
, rec
, ftrace_addr
);
1679 return -1; /* unknow ftrace bug */
1682 static void ftrace_replace_code(int update
)
1684 struct dyn_ftrace
*rec
;
1685 struct ftrace_page
*pg
;
1688 if (unlikely(ftrace_disabled
))
1691 do_for_each_ftrace_rec(pg
, rec
) {
1692 failed
= __ftrace_replace_code(rec
, update
);
1694 ftrace_bug(failed
, rec
->ip
);
1695 /* Stop processing */
1698 } while_for_each_ftrace_rec();
1701 struct ftrace_rec_iter
{
1702 struct ftrace_page
*pg
;
1707 * ftrace_rec_iter_start, start up iterating over traced functions
1709 * Returns an iterator handle that is used to iterate over all
1710 * the records that represent address locations where functions
1713 * May return NULL if no records are available.
1715 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
1718 * We only use a single iterator.
1719 * Protected by the ftrace_lock mutex.
1721 static struct ftrace_rec_iter ftrace_rec_iter
;
1722 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
1724 iter
->pg
= ftrace_pages_start
;
1727 /* Could have empty pages */
1728 while (iter
->pg
&& !iter
->pg
->index
)
1729 iter
->pg
= iter
->pg
->next
;
1738 * ftrace_rec_iter_next, get the next record to process.
1739 * @iter: The handle to the iterator.
1741 * Returns the next iterator after the given iterator @iter.
1743 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
1747 if (iter
->index
>= iter
->pg
->index
) {
1748 iter
->pg
= iter
->pg
->next
;
1751 /* Could have empty pages */
1752 while (iter
->pg
&& !iter
->pg
->index
)
1753 iter
->pg
= iter
->pg
->next
;
1763 * ftrace_rec_iter_record, get the record at the iterator location
1764 * @iter: The current iterator location
1766 * Returns the record that the current @iter is at.
1768 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
1770 return &iter
->pg
->records
[iter
->index
];
1774 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
1781 if (unlikely(ftrace_disabled
))
1784 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
1786 ftrace_bug(ret
, ip
);
1793 * archs can override this function if they must do something
1794 * before the modifying code is performed.
1796 int __weak
ftrace_arch_code_modify_prepare(void)
1802 * archs can override this function if they must do something
1803 * after the modifying code is performed.
1805 int __weak
ftrace_arch_code_modify_post_process(void)
1810 static int __ftrace_modify_code(void *data
)
1812 int *command
= data
;
1814 if (*command
& FTRACE_UPDATE_CALLS
)
1815 ftrace_replace_code(1);
1816 else if (*command
& FTRACE_DISABLE_CALLS
)
1817 ftrace_replace_code(0);
1819 if (*command
& FTRACE_UPDATE_TRACE_FUNC
)
1820 ftrace_update_ftrace_func(ftrace_trace_function
);
1822 if (*command
& FTRACE_START_FUNC_RET
)
1823 ftrace_enable_ftrace_graph_caller();
1824 else if (*command
& FTRACE_STOP_FUNC_RET
)
1825 ftrace_disable_ftrace_graph_caller();
1831 * ftrace_run_stop_machine, go back to the stop machine method
1832 * @command: The command to tell ftrace what to do
1834 * If an arch needs to fall back to the stop machine method, the
1835 * it can call this function.
1837 void ftrace_run_stop_machine(int command
)
1839 stop_machine(__ftrace_modify_code
, &command
, NULL
);
1843 * arch_ftrace_update_code, modify the code to trace or not trace
1844 * @command: The command that needs to be done
1846 * Archs can override this function if it does not need to
1847 * run stop_machine() to modify code.
1849 void __weak
arch_ftrace_update_code(int command
)
1851 ftrace_run_stop_machine(command
);
1854 static void ftrace_run_update_code(int command
)
1858 ret
= ftrace_arch_code_modify_prepare();
1859 FTRACE_WARN_ON(ret
);
1863 * Do not call function tracer while we update the code.
1864 * We are in stop machine.
1866 function_trace_stop
++;
1869 * By default we use stop_machine() to modify the code.
1870 * But archs can do what ever they want as long as it
1871 * is safe. The stop_machine() is the safest, but also
1872 * produces the most overhead.
1874 arch_ftrace_update_code(command
);
1876 #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
1878 * For archs that call ftrace_test_stop_func(), we must
1879 * wait till after we update all the function callers
1880 * before we update the callback. This keeps different
1881 * ops that record different functions from corrupting
1884 __ftrace_trace_function
= __ftrace_trace_function_delay
;
1886 function_trace_stop
--;
1888 ret
= ftrace_arch_code_modify_post_process();
1889 FTRACE_WARN_ON(ret
);
1892 static ftrace_func_t saved_ftrace_func
;
1893 static int ftrace_start_up
;
1894 static int global_start_up
;
1896 static void ftrace_startup_enable(int command
)
1898 if (saved_ftrace_func
!= ftrace_trace_function
) {
1899 saved_ftrace_func
= ftrace_trace_function
;
1900 command
|= FTRACE_UPDATE_TRACE_FUNC
;
1903 if (!command
|| !ftrace_enabled
)
1906 ftrace_run_update_code(command
);
1909 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
1911 bool hash_enable
= true;
1913 if (unlikely(ftrace_disabled
))
1917 command
|= FTRACE_UPDATE_CALLS
;
1919 /* ops marked global share the filter hashes */
1920 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
1922 /* Don't update hash if global is already set */
1923 if (global_start_up
)
1924 hash_enable
= false;
1928 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
1930 ftrace_hash_rec_enable(ops
, 1);
1932 ftrace_startup_enable(command
);
1937 static void ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
1939 bool hash_disable
= true;
1941 if (unlikely(ftrace_disabled
))
1946 * Just warn in case of unbalance, no need to kill ftrace, it's not
1947 * critical but the ftrace_call callers may be never nopped again after
1948 * further ftrace uses.
1950 WARN_ON_ONCE(ftrace_start_up
< 0);
1952 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
1955 WARN_ON_ONCE(global_start_up
< 0);
1956 /* Don't update hash if global still has users */
1957 if (global_start_up
) {
1958 WARN_ON_ONCE(!ftrace_start_up
);
1959 hash_disable
= false;
1964 ftrace_hash_rec_disable(ops
, 1);
1966 if (ops
!= &global_ops
|| !global_start_up
)
1967 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
1969 command
|= FTRACE_UPDATE_CALLS
;
1971 if (saved_ftrace_func
!= ftrace_trace_function
) {
1972 saved_ftrace_func
= ftrace_trace_function
;
1973 command
|= FTRACE_UPDATE_TRACE_FUNC
;
1976 if (!command
|| !ftrace_enabled
)
1979 ftrace_run_update_code(command
);
1982 static void ftrace_startup_sysctl(void)
1984 if (unlikely(ftrace_disabled
))
1987 /* Force update next time */
1988 saved_ftrace_func
= NULL
;
1989 /* ftrace_start_up is true if we want ftrace running */
1990 if (ftrace_start_up
)
1991 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
1994 static void ftrace_shutdown_sysctl(void)
1996 if (unlikely(ftrace_disabled
))
1999 /* ftrace_start_up is true if ftrace is running */
2000 if (ftrace_start_up
)
2001 ftrace_run_update_code(FTRACE_DISABLE_CALLS
);
2004 static cycle_t ftrace_update_time
;
2005 static unsigned long ftrace_update_cnt
;
2006 unsigned long ftrace_update_tot_cnt
;
2008 static int ops_traces_mod(struct ftrace_ops
*ops
)
2010 struct ftrace_hash
*hash
;
2012 hash
= ops
->filter_hash
;
2013 return ftrace_hash_empty(hash
);
2016 static int ftrace_update_code(struct module
*mod
)
2018 struct ftrace_page
*pg
;
2019 struct dyn_ftrace
*p
;
2020 cycle_t start
, stop
;
2021 unsigned long ref
= 0;
2025 * When adding a module, we need to check if tracers are
2026 * currently enabled and if they are set to trace all functions.
2027 * If they are, we need to enable the module functions as well
2028 * as update the reference counts for those function records.
2031 struct ftrace_ops
*ops
;
2033 for (ops
= ftrace_ops_list
;
2034 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2035 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
&&
2036 ops_traces_mod(ops
))
2041 start
= ftrace_now(raw_smp_processor_id());
2042 ftrace_update_cnt
= 0;
2044 for (pg
= ftrace_new_pgs
; pg
; pg
= pg
->next
) {
2046 for (i
= 0; i
< pg
->index
; i
++) {
2047 /* If something went wrong, bail without enabling anything */
2048 if (unlikely(ftrace_disabled
))
2051 p
= &pg
->records
[i
];
2055 * Do the initial record conversion from mcount jump
2056 * to the NOP instructions.
2058 if (!ftrace_code_disable(mod
, p
))
2061 ftrace_update_cnt
++;
2064 * If the tracing is enabled, go ahead and enable the record.
2066 * The reason not to enable the record immediatelly is the
2067 * inherent check of ftrace_make_nop/ftrace_make_call for
2068 * correct previous instructions. Making first the NOP
2069 * conversion puts the module to the correct state, thus
2070 * passing the ftrace_make_call check.
2072 if (ftrace_start_up
&& ref
) {
2073 int failed
= __ftrace_replace_code(p
, 1);
2075 ftrace_bug(failed
, p
->ip
);
2080 ftrace_new_pgs
= NULL
;
2082 stop
= ftrace_now(raw_smp_processor_id());
2083 ftrace_update_time
= stop
- start
;
2084 ftrace_update_tot_cnt
+= ftrace_update_cnt
;
2089 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2094 if (WARN_ON(!count
))
2097 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2100 * We want to fill as much as possible. No more than a page
2103 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2107 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2110 /* if we can't allocate this size, try something smaller */
2117 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2126 static struct ftrace_page
*
2127 ftrace_allocate_pages(unsigned long num_to_init
)
2129 struct ftrace_page
*start_pg
;
2130 struct ftrace_page
*pg
;
2137 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2142 * Try to allocate as much as possible in one continues
2143 * location that fills in all of the space. We want to
2144 * waste as little space as possible.
2147 cnt
= ftrace_allocate_records(pg
, num_to_init
);
2155 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2166 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
2167 free_pages((unsigned long)pg
->records
, order
);
2168 start_pg
= pg
->next
;
2172 pr_info("ftrace: FAILED to allocate memory for functions\n");
2176 static int __init
ftrace_dyn_table_alloc(unsigned long num_to_init
)
2181 pr_info("ftrace: No functions to be traced?\n");
2185 cnt
= num_to_init
/ ENTRIES_PER_PAGE
;
2186 pr_info("ftrace: allocating %ld entries in %d pages\n",
2187 num_to_init
, cnt
+ 1);
2192 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2194 struct ftrace_iterator
{
2197 struct ftrace_page
*pg
;
2198 struct dyn_ftrace
*func
;
2199 struct ftrace_func_probe
*probe
;
2200 struct trace_parser parser
;
2201 struct ftrace_hash
*hash
;
2202 struct ftrace_ops
*ops
;
2209 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
2211 struct ftrace_iterator
*iter
= m
->private;
2212 struct hlist_node
*hnd
= NULL
;
2213 struct hlist_head
*hhd
;
2219 hnd
= &iter
->probe
->node
;
2221 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
2224 hhd
= &ftrace_func_hash
[iter
->hidx
];
2226 if (hlist_empty(hhd
)) {
2242 if (WARN_ON_ONCE(!hnd
))
2245 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
2250 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
2252 struct ftrace_iterator
*iter
= m
->private;
2256 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
2259 if (iter
->func_pos
> *pos
)
2263 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
2264 p
= t_hash_next(m
, &l
);
2271 /* Only set this if we have an item */
2272 iter
->flags
|= FTRACE_ITER_HASH
;
2278 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
2280 struct ftrace_func_probe
*rec
;
2283 if (WARN_ON_ONCE(!rec
))
2286 if (rec
->ops
->print
)
2287 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
2289 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
2292 seq_printf(m
, ":%p", rec
->data
);
2299 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2301 struct ftrace_iterator
*iter
= m
->private;
2302 struct ftrace_ops
*ops
= iter
->ops
;
2303 struct dyn_ftrace
*rec
= NULL
;
2305 if (unlikely(ftrace_disabled
))
2308 if (iter
->flags
& FTRACE_ITER_HASH
)
2309 return t_hash_next(m
, pos
);
2312 iter
->pos
= iter
->func_pos
= *pos
;
2314 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
2315 return t_hash_start(m
, pos
);
2318 if (iter
->idx
>= iter
->pg
->index
) {
2319 if (iter
->pg
->next
) {
2320 iter
->pg
= iter
->pg
->next
;
2325 rec
= &iter
->pg
->records
[iter
->idx
++];
2326 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
2327 !(ftrace_lookup_ip(ops
->filter_hash
, rec
->ip
))) ||
2329 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
2330 !ftrace_lookup_ip(ops
->notrace_hash
, rec
->ip
)) ||
2332 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
2333 !(rec
->flags
& ~FTRACE_FL_MASK
))) {
2341 return t_hash_start(m
, pos
);
2348 static void reset_iter_read(struct ftrace_iterator
*iter
)
2352 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
& FTRACE_ITER_HASH
);
2355 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2357 struct ftrace_iterator
*iter
= m
->private;
2358 struct ftrace_ops
*ops
= iter
->ops
;
2362 mutex_lock(&ftrace_lock
);
2364 if (unlikely(ftrace_disabled
))
2368 * If an lseek was done, then reset and start from beginning.
2370 if (*pos
< iter
->pos
)
2371 reset_iter_read(iter
);
2374 * For set_ftrace_filter reading, if we have the filter
2375 * off, we can short cut and just print out that all
2376 * functions are enabled.
2378 if (iter
->flags
& FTRACE_ITER_FILTER
&&
2379 ftrace_hash_empty(ops
->filter_hash
)) {
2381 return t_hash_start(m
, pos
);
2382 iter
->flags
|= FTRACE_ITER_PRINTALL
;
2383 /* reset in case of seek/pread */
2384 iter
->flags
&= ~FTRACE_ITER_HASH
;
2388 if (iter
->flags
& FTRACE_ITER_HASH
)
2389 return t_hash_start(m
, pos
);
2392 * Unfortunately, we need to restart at ftrace_pages_start
2393 * every time we let go of the ftrace_mutex. This is because
2394 * those pointers can change without the lock.
2396 iter
->pg
= ftrace_pages_start
;
2398 for (l
= 0; l
<= *pos
; ) {
2399 p
= t_next(m
, p
, &l
);
2405 return t_hash_start(m
, pos
);
2410 static void t_stop(struct seq_file
*m
, void *p
)
2412 mutex_unlock(&ftrace_lock
);
2415 static int t_show(struct seq_file
*m
, void *v
)
2417 struct ftrace_iterator
*iter
= m
->private;
2418 struct dyn_ftrace
*rec
;
2420 if (iter
->flags
& FTRACE_ITER_HASH
)
2421 return t_hash_show(m
, iter
);
2423 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
2424 seq_printf(m
, "#### all functions enabled ####\n");
2433 seq_printf(m
, "%ps", (void *)rec
->ip
);
2434 if (iter
->flags
& FTRACE_ITER_ENABLED
)
2435 seq_printf(m
, " (%ld)",
2436 rec
->flags
& ~FTRACE_FL_MASK
);
2437 seq_printf(m
, "\n");
2442 static const struct seq_operations show_ftrace_seq_ops
= {
2450 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
2452 struct ftrace_iterator
*iter
;
2454 if (unlikely(ftrace_disabled
))
2457 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2459 iter
->pg
= ftrace_pages_start
;
2460 iter
->ops
= &global_ops
;
2463 return iter
? 0 : -ENOMEM
;
2467 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
2469 struct ftrace_iterator
*iter
;
2471 if (unlikely(ftrace_disabled
))
2474 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2476 iter
->pg
= ftrace_pages_start
;
2477 iter
->flags
= FTRACE_ITER_ENABLED
;
2478 iter
->ops
= &global_ops
;
2481 return iter
? 0 : -ENOMEM
;
2484 static void ftrace_filter_reset(struct ftrace_hash
*hash
)
2486 mutex_lock(&ftrace_lock
);
2487 ftrace_hash_clear(hash
);
2488 mutex_unlock(&ftrace_lock
);
2492 * ftrace_regex_open - initialize function tracer filter files
2493 * @ops: The ftrace_ops that hold the hash filters
2494 * @flag: The type of filter to process
2495 * @inode: The inode, usually passed in to your open routine
2496 * @file: The file, usually passed in to your open routine
2498 * ftrace_regex_open() initializes the filter files for the
2499 * @ops. Depending on @flag it may process the filter hash or
2500 * the notrace hash of @ops. With this called from the open
2501 * routine, you can use ftrace_filter_write() for the write
2502 * routine if @flag has FTRACE_ITER_FILTER set, or
2503 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2504 * ftrace_regex_lseek() should be used as the lseek routine, and
2505 * release must call ftrace_regex_release().
2508 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
2509 struct inode
*inode
, struct file
*file
)
2511 struct ftrace_iterator
*iter
;
2512 struct ftrace_hash
*hash
;
2515 if (unlikely(ftrace_disabled
))
2518 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2522 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
2527 if (flag
& FTRACE_ITER_NOTRACE
)
2528 hash
= ops
->notrace_hash
;
2530 hash
= ops
->filter_hash
;
2535 if (file
->f_mode
& FMODE_WRITE
) {
2536 mutex_lock(&ftrace_lock
);
2537 iter
->hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, hash
);
2538 mutex_unlock(&ftrace_lock
);
2541 trace_parser_put(&iter
->parser
);
2547 mutex_lock(&ftrace_regex_lock
);
2549 if ((file
->f_mode
& FMODE_WRITE
) &&
2550 (file
->f_flags
& O_TRUNC
))
2551 ftrace_filter_reset(iter
->hash
);
2553 if (file
->f_mode
& FMODE_READ
) {
2554 iter
->pg
= ftrace_pages_start
;
2556 ret
= seq_open(file
, &show_ftrace_seq_ops
);
2558 struct seq_file
*m
= file
->private_data
;
2562 free_ftrace_hash(iter
->hash
);
2563 trace_parser_put(&iter
->parser
);
2567 file
->private_data
= iter
;
2568 mutex_unlock(&ftrace_regex_lock
);
2574 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
2576 return ftrace_regex_open(&global_ops
,
2577 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
2582 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
2584 return ftrace_regex_open(&global_ops
, FTRACE_ITER_NOTRACE
,
2589 ftrace_regex_lseek(struct file
*file
, loff_t offset
, int origin
)
2593 if (file
->f_mode
& FMODE_READ
)
2594 ret
= seq_lseek(file
, offset
, origin
);
2596 file
->f_pos
= ret
= 1;
2601 static int ftrace_match(char *str
, char *regex
, int len
, int type
)
2608 if (strcmp(str
, regex
) == 0)
2611 case MATCH_FRONT_ONLY
:
2612 if (strncmp(str
, regex
, len
) == 0)
2615 case MATCH_MIDDLE_ONLY
:
2616 if (strstr(str
, regex
))
2619 case MATCH_END_ONLY
:
2621 if (slen
>= len
&& memcmp(str
+ slen
- len
, regex
, len
) == 0)
2630 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int not)
2632 struct ftrace_func_entry
*entry
;
2635 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
2637 /* Do nothing if it doesn't exist */
2641 free_hash_entry(hash
, entry
);
2643 /* Do nothing if it exists */
2647 ret
= add_hash_entry(hash
, rec
->ip
);
2653 ftrace_match_record(struct dyn_ftrace
*rec
, char *mod
,
2654 char *regex
, int len
, int type
)
2656 char str
[KSYM_SYMBOL_LEN
];
2659 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
2662 /* module lookup requires matching the module */
2663 if (!modname
|| strcmp(modname
, mod
))
2666 /* blank search means to match all funcs in the mod */
2671 return ftrace_match(str
, regex
, len
, type
);
2675 match_records(struct ftrace_hash
*hash
, char *buff
,
2676 int len
, char *mod
, int not)
2678 unsigned search_len
= 0;
2679 struct ftrace_page
*pg
;
2680 struct dyn_ftrace
*rec
;
2681 int type
= MATCH_FULL
;
2682 char *search
= buff
;
2687 type
= filter_parse_regex(buff
, len
, &search
, ¬);
2688 search_len
= strlen(search
);
2691 mutex_lock(&ftrace_lock
);
2693 if (unlikely(ftrace_disabled
))
2696 do_for_each_ftrace_rec(pg
, rec
) {
2697 if (ftrace_match_record(rec
, mod
, search
, search_len
, type
)) {
2698 ret
= enter_record(hash
, rec
, not);
2705 } while_for_each_ftrace_rec();
2707 mutex_unlock(&ftrace_lock
);
2713 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
2715 return match_records(hash
, buff
, len
, NULL
, 0);
2719 ftrace_match_module_records(struct ftrace_hash
*hash
, char *buff
, char *mod
)
2723 /* blank or '*' mean the same */
2724 if (strcmp(buff
, "*") == 0)
2727 /* handle the case of 'dont filter this module' */
2728 if (strcmp(buff
, "!") == 0 || strcmp(buff
, "!*") == 0) {
2733 return match_records(hash
, buff
, strlen(buff
), mod
, not);
2737 * We register the module command as a template to show others how
2738 * to register the a command as well.
2742 ftrace_mod_callback(struct ftrace_hash
*hash
,
2743 char *func
, char *cmd
, char *param
, int enable
)
2749 * cmd == 'mod' because we only registered this func
2750 * for the 'mod' ftrace_func_command.
2751 * But if you register one func with multiple commands,
2752 * you can tell which command was used by the cmd
2756 /* we must have a module name */
2760 mod
= strsep(¶m
, ":");
2764 ret
= ftrace_match_module_records(hash
, func
, mod
);
2773 static struct ftrace_func_command ftrace_mod_cmd
= {
2775 .func
= ftrace_mod_callback
,
2778 static int __init
ftrace_mod_cmd_init(void)
2780 return register_ftrace_command(&ftrace_mod_cmd
);
2782 device_initcall(ftrace_mod_cmd_init
);
2785 function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
)
2787 struct ftrace_func_probe
*entry
;
2788 struct hlist_head
*hhd
;
2789 struct hlist_node
*n
;
2792 key
= hash_long(ip
, FTRACE_HASH_BITS
);
2794 hhd
= &ftrace_func_hash
[key
];
2796 if (hlist_empty(hhd
))
2800 * Disable preemption for these calls to prevent a RCU grace
2801 * period. This syncs the hash iteration and freeing of items
2802 * on the hash. rcu_read_lock is too dangerous here.
2804 preempt_disable_notrace();
2805 hlist_for_each_entry_rcu(entry
, n
, hhd
, node
) {
2806 if (entry
->ip
== ip
)
2807 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
2809 preempt_enable_notrace();
2812 static struct ftrace_ops trace_probe_ops __read_mostly
=
2814 .func
= function_trace_probe_call
,
2817 static int ftrace_probe_registered
;
2819 static void __enable_ftrace_function_probe(void)
2824 if (ftrace_probe_registered
)
2827 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
2828 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
2832 /* Nothing registered? */
2833 if (i
== FTRACE_FUNC_HASHSIZE
)
2836 ret
= __register_ftrace_function(&trace_probe_ops
);
2838 ret
= ftrace_startup(&trace_probe_ops
, 0);
2840 ftrace_probe_registered
= 1;
2843 static void __disable_ftrace_function_probe(void)
2848 if (!ftrace_probe_registered
)
2851 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
2852 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
2857 /* no more funcs left */
2858 ret
= __unregister_ftrace_function(&trace_probe_ops
);
2860 ftrace_shutdown(&trace_probe_ops
, 0);
2862 ftrace_probe_registered
= 0;
2866 static void ftrace_free_entry_rcu(struct rcu_head
*rhp
)
2868 struct ftrace_func_probe
*entry
=
2869 container_of(rhp
, struct ftrace_func_probe
, rcu
);
2871 if (entry
->ops
->free
)
2872 entry
->ops
->free(&entry
->data
);
2878 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
2881 struct ftrace_func_probe
*entry
;
2882 struct ftrace_page
*pg
;
2883 struct dyn_ftrace
*rec
;
2889 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
2890 len
= strlen(search
);
2892 /* we do not support '!' for function probes */
2896 mutex_lock(&ftrace_lock
);
2898 if (unlikely(ftrace_disabled
))
2901 do_for_each_ftrace_rec(pg
, rec
) {
2903 if (!ftrace_match_record(rec
, NULL
, search
, len
, type
))
2906 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
2908 /* If we did not process any, then return error */
2919 * The caller might want to do something special
2920 * for each function we find. We call the callback
2921 * to give the caller an opportunity to do so.
2923 if (ops
->callback
) {
2924 if (ops
->callback(rec
->ip
, &entry
->data
) < 0) {
2925 /* caller does not like this func */
2932 entry
->ip
= rec
->ip
;
2934 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
2935 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
2937 } while_for_each_ftrace_rec();
2938 __enable_ftrace_function_probe();
2941 mutex_unlock(&ftrace_lock
);
2947 PROBE_TEST_FUNC
= 1,
2952 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
2953 void *data
, int flags
)
2955 struct ftrace_func_probe
*entry
;
2956 struct hlist_node
*n
, *tmp
;
2957 char str
[KSYM_SYMBOL_LEN
];
2958 int type
= MATCH_FULL
;
2962 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
2967 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
2968 len
= strlen(search
);
2970 /* we do not support '!' for function probes */
2975 mutex_lock(&ftrace_lock
);
2976 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
2977 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
2979 hlist_for_each_entry_safe(entry
, n
, tmp
, hhd
, node
) {
2981 /* break up if statements for readability */
2982 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
2985 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
2988 /* do this last, since it is the most expensive */
2990 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
2992 if (!ftrace_match(str
, glob
, len
, type
))
2996 hlist_del(&entry
->node
);
2997 call_rcu(&entry
->rcu
, ftrace_free_entry_rcu
);
3000 __disable_ftrace_function_probe();
3001 mutex_unlock(&ftrace_lock
);
3005 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3008 __unregister_ftrace_function_probe(glob
, ops
, data
,
3009 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3013 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3015 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3018 void unregister_ftrace_function_probe_all(char *glob
)
3020 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3023 static LIST_HEAD(ftrace_commands
);
3024 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3026 int register_ftrace_command(struct ftrace_func_command
*cmd
)
3028 struct ftrace_func_command
*p
;
3031 mutex_lock(&ftrace_cmd_mutex
);
3032 list_for_each_entry(p
, &ftrace_commands
, list
) {
3033 if (strcmp(cmd
->name
, p
->name
) == 0) {
3038 list_add(&cmd
->list
, &ftrace_commands
);
3040 mutex_unlock(&ftrace_cmd_mutex
);
3045 int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
3047 struct ftrace_func_command
*p
, *n
;
3050 mutex_lock(&ftrace_cmd_mutex
);
3051 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
3052 if (strcmp(cmd
->name
, p
->name
) == 0) {
3054 list_del_init(&p
->list
);
3059 mutex_unlock(&ftrace_cmd_mutex
);
3064 static int ftrace_process_regex(struct ftrace_hash
*hash
,
3065 char *buff
, int len
, int enable
)
3067 char *func
, *command
, *next
= buff
;
3068 struct ftrace_func_command
*p
;
3071 func
= strsep(&next
, ":");
3074 ret
= ftrace_match_records(hash
, func
, len
);
3084 command
= strsep(&next
, ":");
3086 mutex_lock(&ftrace_cmd_mutex
);
3087 list_for_each_entry(p
, &ftrace_commands
, list
) {
3088 if (strcmp(p
->name
, command
) == 0) {
3089 ret
= p
->func(hash
, func
, command
, next
, enable
);
3094 mutex_unlock(&ftrace_cmd_mutex
);
3100 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
3101 size_t cnt
, loff_t
*ppos
, int enable
)
3103 struct ftrace_iterator
*iter
;
3104 struct trace_parser
*parser
;
3110 mutex_lock(&ftrace_regex_lock
);
3113 if (unlikely(ftrace_disabled
))
3116 if (file
->f_mode
& FMODE_READ
) {
3117 struct seq_file
*m
= file
->private_data
;
3120 iter
= file
->private_data
;
3122 parser
= &iter
->parser
;
3123 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
3125 if (read
>= 0 && trace_parser_loaded(parser
) &&
3126 !trace_parser_cont(parser
)) {
3127 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
3128 parser
->idx
, enable
);
3129 trace_parser_clear(parser
);
3136 mutex_unlock(&ftrace_regex_lock
);
3142 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
3143 size_t cnt
, loff_t
*ppos
)
3145 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
3149 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
3150 size_t cnt
, loff_t
*ppos
)
3152 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
3156 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3157 int reset
, int enable
)
3159 struct ftrace_hash
**orig_hash
;
3160 struct ftrace_hash
*hash
;
3163 /* All global ops uses the global ops filters */
3164 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
)
3167 if (unlikely(ftrace_disabled
))
3171 orig_hash
= &ops
->filter_hash
;
3173 orig_hash
= &ops
->notrace_hash
;
3175 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3179 mutex_lock(&ftrace_regex_lock
);
3181 ftrace_filter_reset(hash
);
3182 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
3184 goto out_regex_unlock
;
3187 mutex_lock(&ftrace_lock
);
3188 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3189 if (!ret
&& ops
->flags
& FTRACE_OPS_FL_ENABLED
3191 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3193 mutex_unlock(&ftrace_lock
);
3196 mutex_unlock(&ftrace_regex_lock
);
3198 free_ftrace_hash(hash
);
3203 * ftrace_set_filter - set a function to filter on in ftrace
3204 * @ops - the ops to set the filter with
3205 * @buf - the string that holds the function filter text.
3206 * @len - the length of the string.
3207 * @reset - non zero to reset all filters before applying this filter.
3209 * Filters denote which functions should be enabled when tracing is enabled.
3210 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3212 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
3215 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
3217 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
3220 * ftrace_set_notrace - set a function to not trace in ftrace
3221 * @ops - the ops to set the notrace filter with
3222 * @buf - the string that holds the function notrace text.
3223 * @len - the length of the string.
3224 * @reset - non zero to reset all filters before applying this filter.
3226 * Notrace Filters denote which functions should not be enabled when tracing
3227 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3230 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
3233 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
3235 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
3237 * ftrace_set_filter - set a function to filter on in ftrace
3238 * @ops - the ops to set the filter with
3239 * @buf - the string that holds the function filter text.
3240 * @len - the length of the string.
3241 * @reset - non zero to reset all filters before applying this filter.
3243 * Filters denote which functions should be enabled when tracing is enabled.
3244 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3246 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
3248 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
3250 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
3253 * ftrace_set_notrace - set a function to not trace in ftrace
3254 * @ops - the ops to set the notrace filter with
3255 * @buf - the string that holds the function notrace text.
3256 * @len - the length of the string.
3257 * @reset - non zero to reset all filters before applying this filter.
3259 * Notrace Filters denote which functions should not be enabled when tracing
3260 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3263 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
3265 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
3267 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
3270 * command line interface to allow users to set filters on boot up.
3272 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3273 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3274 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3276 static int __init
set_ftrace_notrace(char *str
)
3278 strncpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
3281 __setup("ftrace_notrace=", set_ftrace_notrace
);
3283 static int __init
set_ftrace_filter(char *str
)
3285 strncpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
3288 __setup("ftrace_filter=", set_ftrace_filter
);
3290 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3291 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3292 static int ftrace_set_func(unsigned long *array
, int *idx
, char *buffer
);
3294 static int __init
set_graph_function(char *str
)
3296 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
3299 __setup("ftrace_graph_filter=", set_graph_function
);
3301 static void __init
set_ftrace_early_graph(char *buf
)
3307 func
= strsep(&buf
, ",");
3308 /* we allow only one expression at a time */
3309 ret
= ftrace_set_func(ftrace_graph_funcs
, &ftrace_graph_count
,
3312 printk(KERN_DEBUG
"ftrace: function %s not "
3313 "traceable\n", func
);
3316 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3319 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
3324 func
= strsep(&buf
, ",");
3325 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
3329 static void __init
set_ftrace_early_filters(void)
3331 if (ftrace_filter_buf
[0])
3332 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
3333 if (ftrace_notrace_buf
[0])
3334 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
3335 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3336 if (ftrace_graph_buf
[0])
3337 set_ftrace_early_graph(ftrace_graph_buf
);
3338 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3341 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
3343 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
3344 struct ftrace_iterator
*iter
;
3345 struct ftrace_hash
**orig_hash
;
3346 struct trace_parser
*parser
;
3350 mutex_lock(&ftrace_regex_lock
);
3351 if (file
->f_mode
& FMODE_READ
) {
3354 seq_release(inode
, file
);
3356 iter
= file
->private_data
;
3358 parser
= &iter
->parser
;
3359 if (trace_parser_loaded(parser
)) {
3360 parser
->buffer
[parser
->idx
] = 0;
3361 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
3364 trace_parser_put(parser
);
3366 if (file
->f_mode
& FMODE_WRITE
) {
3367 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
3370 orig_hash
= &iter
->ops
->filter_hash
;
3372 orig_hash
= &iter
->ops
->notrace_hash
;
3374 mutex_lock(&ftrace_lock
);
3375 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
3376 orig_hash
, iter
->hash
);
3377 if (!ret
&& (iter
->ops
->flags
& FTRACE_OPS_FL_ENABLED
)
3379 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3381 mutex_unlock(&ftrace_lock
);
3383 free_ftrace_hash(iter
->hash
);
3386 mutex_unlock(&ftrace_regex_lock
);
3390 static const struct file_operations ftrace_avail_fops
= {
3391 .open
= ftrace_avail_open
,
3393 .llseek
= seq_lseek
,
3394 .release
= seq_release_private
,
3397 static const struct file_operations ftrace_enabled_fops
= {
3398 .open
= ftrace_enabled_open
,
3400 .llseek
= seq_lseek
,
3401 .release
= seq_release_private
,
3404 static const struct file_operations ftrace_filter_fops
= {
3405 .open
= ftrace_filter_open
,
3407 .write
= ftrace_filter_write
,
3408 .llseek
= ftrace_regex_lseek
,
3409 .release
= ftrace_regex_release
,
3412 static const struct file_operations ftrace_notrace_fops
= {
3413 .open
= ftrace_notrace_open
,
3415 .write
= ftrace_notrace_write
,
3416 .llseek
= ftrace_regex_lseek
,
3417 .release
= ftrace_regex_release
,
3420 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3422 static DEFINE_MUTEX(graph_lock
);
3424 int ftrace_graph_count
;
3425 int ftrace_graph_filter_enabled
;
3426 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
3429 __g_next(struct seq_file
*m
, loff_t
*pos
)
3431 if (*pos
>= ftrace_graph_count
)
3433 return &ftrace_graph_funcs
[*pos
];
3437 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3440 return __g_next(m
, pos
);
3443 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
3445 mutex_lock(&graph_lock
);
3447 /* Nothing, tell g_show to print all functions are enabled */
3448 if (!ftrace_graph_filter_enabled
&& !*pos
)
3451 return __g_next(m
, pos
);
3454 static void g_stop(struct seq_file
*m
, void *p
)
3456 mutex_unlock(&graph_lock
);
3459 static int g_show(struct seq_file
*m
, void *v
)
3461 unsigned long *ptr
= v
;
3466 if (ptr
== (unsigned long *)1) {
3467 seq_printf(m
, "#### all functions enabled ####\n");
3471 seq_printf(m
, "%ps\n", (void *)*ptr
);
3476 static const struct seq_operations ftrace_graph_seq_ops
= {
3484 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
3488 if (unlikely(ftrace_disabled
))
3491 mutex_lock(&graph_lock
);
3492 if ((file
->f_mode
& FMODE_WRITE
) &&
3493 (file
->f_flags
& O_TRUNC
)) {
3494 ftrace_graph_filter_enabled
= 0;
3495 ftrace_graph_count
= 0;
3496 memset(ftrace_graph_funcs
, 0, sizeof(ftrace_graph_funcs
));
3498 mutex_unlock(&graph_lock
);
3500 if (file
->f_mode
& FMODE_READ
)
3501 ret
= seq_open(file
, &ftrace_graph_seq_ops
);
3507 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
3509 if (file
->f_mode
& FMODE_READ
)
3510 seq_release(inode
, file
);
3515 ftrace_set_func(unsigned long *array
, int *idx
, char *buffer
)
3517 struct dyn_ftrace
*rec
;
3518 struct ftrace_page
*pg
;
3527 type
= filter_parse_regex(buffer
, strlen(buffer
), &search
, ¬);
3528 if (!not && *idx
>= FTRACE_GRAPH_MAX_FUNCS
)
3531 search_len
= strlen(search
);
3533 mutex_lock(&ftrace_lock
);
3535 if (unlikely(ftrace_disabled
)) {
3536 mutex_unlock(&ftrace_lock
);
3540 do_for_each_ftrace_rec(pg
, rec
) {
3542 if (ftrace_match_record(rec
, NULL
, search
, search_len
, type
)) {
3543 /* if it is in the array */
3545 for (i
= 0; i
< *idx
; i
++) {
3546 if (array
[i
] == rec
->ip
) {
3555 array
[(*idx
)++] = rec
->ip
;
3556 if (*idx
>= FTRACE_GRAPH_MAX_FUNCS
)
3561 array
[i
] = array
[--(*idx
)];
3567 } while_for_each_ftrace_rec();
3569 mutex_unlock(&ftrace_lock
);
3574 ftrace_graph_filter_enabled
= 1;
3579 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
3580 size_t cnt
, loff_t
*ppos
)
3582 struct trace_parser parser
;
3588 mutex_lock(&graph_lock
);
3590 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
)) {
3595 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
3597 if (read
>= 0 && trace_parser_loaded((&parser
))) {
3598 parser
.buffer
[parser
.idx
] = 0;
3600 /* we allow only one expression at a time */
3601 ret
= ftrace_set_func(ftrace_graph_funcs
, &ftrace_graph_count
,
3610 trace_parser_put(&parser
);
3612 mutex_unlock(&graph_lock
);
3617 static const struct file_operations ftrace_graph_fops
= {
3618 .open
= ftrace_graph_open
,
3620 .write
= ftrace_graph_write
,
3621 .release
= ftrace_graph_release
,
3622 .llseek
= seq_lseek
,
3624 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3626 static __init
int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
)
3629 trace_create_file("available_filter_functions", 0444,
3630 d_tracer
, NULL
, &ftrace_avail_fops
);
3632 trace_create_file("enabled_functions", 0444,
3633 d_tracer
, NULL
, &ftrace_enabled_fops
);
3635 trace_create_file("set_ftrace_filter", 0644, d_tracer
,
3636 NULL
, &ftrace_filter_fops
);
3638 trace_create_file("set_ftrace_notrace", 0644, d_tracer
,
3639 NULL
, &ftrace_notrace_fops
);
3641 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3642 trace_create_file("set_graph_function", 0444, d_tracer
,
3644 &ftrace_graph_fops
);
3645 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3650 static int ftrace_cmp_ips(const void *a
, const void *b
)
3652 const unsigned long *ipa
= a
;
3653 const unsigned long *ipb
= b
;
3662 static void ftrace_swap_ips(void *a
, void *b
, int size
)
3664 unsigned long *ipa
= a
;
3665 unsigned long *ipb
= b
;
3673 static int ftrace_process_locs(struct module
*mod
,
3674 unsigned long *start
,
3677 struct ftrace_page
*start_pg
;
3678 struct ftrace_page
*pg
;
3679 struct dyn_ftrace
*rec
;
3680 unsigned long count
;
3683 unsigned long flags
= 0; /* Shut up gcc */
3686 count
= end
- start
;
3691 sort(start
, count
, sizeof(*start
),
3692 ftrace_cmp_ips
, ftrace_swap_ips
);
3694 start_pg
= ftrace_allocate_pages(count
);
3698 mutex_lock(&ftrace_lock
);
3701 * Core and each module needs their own pages, as
3702 * modules will free them when they are removed.
3703 * Force a new page to be allocated for modules.
3706 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
3707 /* First initialization */
3708 ftrace_pages
= ftrace_pages_start
= start_pg
;
3713 if (WARN_ON(ftrace_pages
->next
)) {
3714 /* Hmm, we have free pages? */
3715 while (ftrace_pages
->next
)
3716 ftrace_pages
= ftrace_pages
->next
;
3719 ftrace_pages
->next
= start_pg
;
3725 addr
= ftrace_call_adjust(*p
++);
3727 * Some architecture linkers will pad between
3728 * the different mcount_loc sections of different
3729 * object files to satisfy alignments.
3730 * Skip any NULL pointers.
3735 if (pg
->index
== pg
->size
) {
3736 /* We should have allocated enough */
3737 if (WARN_ON(!pg
->next
))
3742 rec
= &pg
->records
[pg
->index
++];
3746 /* We should have used all pages */
3749 /* Assign the last page to ftrace_pages */
3752 /* These new locations need to be initialized */
3753 ftrace_new_pgs
= start_pg
;
3756 * We only need to disable interrupts on start up
3757 * because we are modifying code that an interrupt
3758 * may execute, and the modification is not atomic.
3759 * But for modules, nothing runs the code we modify
3760 * until we are finished with it, and there's no
3761 * reason to cause large interrupt latencies while we do it.
3764 local_irq_save(flags
);
3765 ftrace_update_code(mod
);
3767 local_irq_restore(flags
);
3770 mutex_unlock(&ftrace_lock
);
3775 #ifdef CONFIG_MODULES
3777 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
3779 void ftrace_release_mod(struct module
*mod
)
3781 struct dyn_ftrace
*rec
;
3782 struct ftrace_page
**last_pg
;
3783 struct ftrace_page
*pg
;
3786 mutex_lock(&ftrace_lock
);
3788 if (ftrace_disabled
)
3792 * Each module has its own ftrace_pages, remove
3793 * them from the list.
3795 last_pg
= &ftrace_pages_start
;
3796 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
3797 rec
= &pg
->records
[0];
3798 if (within_module_core(rec
->ip
, mod
)) {
3800 * As core pages are first, the first
3801 * page should never be a module page.
3803 if (WARN_ON(pg
== ftrace_pages_start
))
3806 /* Check if we are deleting the last page */
3807 if (pg
== ftrace_pages
)
3808 ftrace_pages
= next_to_ftrace_page(last_pg
);
3810 *last_pg
= pg
->next
;
3811 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
3812 free_pages((unsigned long)pg
->records
, order
);
3815 last_pg
= &pg
->next
;
3818 mutex_unlock(&ftrace_lock
);
3821 static void ftrace_init_module(struct module
*mod
,
3822 unsigned long *start
, unsigned long *end
)
3824 if (ftrace_disabled
|| start
== end
)
3826 ftrace_process_locs(mod
, start
, end
);
3829 static int ftrace_module_notify(struct notifier_block
*self
,
3830 unsigned long val
, void *data
)
3832 struct module
*mod
= data
;
3835 case MODULE_STATE_COMING
:
3836 ftrace_init_module(mod
, mod
->ftrace_callsites
,
3837 mod
->ftrace_callsites
+
3838 mod
->num_ftrace_callsites
);
3840 case MODULE_STATE_GOING
:
3841 ftrace_release_mod(mod
);
3848 static int ftrace_module_notify(struct notifier_block
*self
,
3849 unsigned long val
, void *data
)
3853 #endif /* CONFIG_MODULES */
3855 struct notifier_block ftrace_module_nb
= {
3856 .notifier_call
= ftrace_module_notify
,
3860 extern unsigned long __start_mcount_loc
[];
3861 extern unsigned long __stop_mcount_loc
[];
3863 void __init
ftrace_init(void)
3865 unsigned long count
, addr
, flags
;
3868 /* Keep the ftrace pointer to the stub */
3869 addr
= (unsigned long)ftrace_stub
;
3871 local_irq_save(flags
);
3872 ftrace_dyn_arch_init(&addr
);
3873 local_irq_restore(flags
);
3875 /* ftrace_dyn_arch_init places the return code in addr */
3879 count
= __stop_mcount_loc
- __start_mcount_loc
;
3881 ret
= ftrace_dyn_table_alloc(count
);
3885 last_ftrace_enabled
= ftrace_enabled
= 1;
3887 ret
= ftrace_process_locs(NULL
,
3891 ret
= register_module_notifier(&ftrace_module_nb
);
3893 pr_warning("Failed to register trace ftrace module notifier\n");
3895 set_ftrace_early_filters();
3899 ftrace_disabled
= 1;
3904 static struct ftrace_ops global_ops
= {
3905 .func
= ftrace_stub
,
3908 static int __init
ftrace_nodyn_init(void)
3913 device_initcall(ftrace_nodyn_init
);
3915 static inline int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
) { return 0; }
3916 static inline void ftrace_startup_enable(int command
) { }
3917 /* Keep as macros so we do not need to define the commands */
3918 # define ftrace_startup(ops, command) \
3920 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
3923 # define ftrace_shutdown(ops, command) do { } while (0)
3924 # define ftrace_startup_sysctl() do { } while (0)
3925 # define ftrace_shutdown_sysctl() do { } while (0)
3928 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
)
3933 #endif /* CONFIG_DYNAMIC_FTRACE */
3936 ftrace_ops_control_func(unsigned long ip
, unsigned long parent_ip
)
3938 struct ftrace_ops
*op
;
3940 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT
)))
3944 * Some of the ops may be dynamically allocated,
3945 * they must be freed after a synchronize_sched().
3947 preempt_disable_notrace();
3948 trace_recursion_set(TRACE_CONTROL_BIT
);
3949 op
= rcu_dereference_raw(ftrace_control_list
);
3950 while (op
!= &ftrace_list_end
) {
3951 if (!ftrace_function_local_disabled(op
) &&
3952 ftrace_ops_test(op
, ip
))
3953 op
->func(ip
, parent_ip
);
3955 op
= rcu_dereference_raw(op
->next
);
3957 trace_recursion_clear(TRACE_CONTROL_BIT
);
3958 preempt_enable_notrace();
3961 static struct ftrace_ops control_ops
= {
3962 .func
= ftrace_ops_control_func
,
3966 ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
)
3968 struct ftrace_ops
*op
;
3970 if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT
)))
3973 trace_recursion_set(TRACE_INTERNAL_BIT
);
3975 * Some of the ops may be dynamically allocated,
3976 * they must be freed after a synchronize_sched().
3978 preempt_disable_notrace();
3979 op
= rcu_dereference_raw(ftrace_ops_list
);
3980 while (op
!= &ftrace_list_end
) {
3981 if (ftrace_ops_test(op
, ip
))
3982 op
->func(ip
, parent_ip
);
3983 op
= rcu_dereference_raw(op
->next
);
3985 preempt_enable_notrace();
3986 trace_recursion_clear(TRACE_INTERNAL_BIT
);
3989 static void clear_ftrace_swapper(void)
3991 struct task_struct
*p
;
3995 for_each_online_cpu(cpu
) {
3997 clear_tsk_trace_trace(p
);
4002 static void set_ftrace_swapper(void)
4004 struct task_struct
*p
;
4008 for_each_online_cpu(cpu
) {
4010 set_tsk_trace_trace(p
);
4015 static void clear_ftrace_pid(struct pid
*pid
)
4017 struct task_struct
*p
;
4020 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4021 clear_tsk_trace_trace(p
);
4022 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4028 static void set_ftrace_pid(struct pid
*pid
)
4030 struct task_struct
*p
;
4033 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4034 set_tsk_trace_trace(p
);
4035 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4039 static void clear_ftrace_pid_task(struct pid
*pid
)
4041 if (pid
== ftrace_swapper_pid
)
4042 clear_ftrace_swapper();
4044 clear_ftrace_pid(pid
);
4047 static void set_ftrace_pid_task(struct pid
*pid
)
4049 if (pid
== ftrace_swapper_pid
)
4050 set_ftrace_swapper();
4052 set_ftrace_pid(pid
);
4055 static int ftrace_pid_add(int p
)
4058 struct ftrace_pid
*fpid
;
4061 mutex_lock(&ftrace_lock
);
4064 pid
= ftrace_swapper_pid
;
4066 pid
= find_get_pid(p
);
4073 list_for_each_entry(fpid
, &ftrace_pids
, list
)
4074 if (fpid
->pid
== pid
)
4079 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
4083 list_add(&fpid
->list
, &ftrace_pids
);
4086 set_ftrace_pid_task(pid
);
4088 ftrace_update_pid_func();
4089 ftrace_startup_enable(0);
4091 mutex_unlock(&ftrace_lock
);
4095 if (pid
!= ftrace_swapper_pid
)
4099 mutex_unlock(&ftrace_lock
);
4103 static void ftrace_pid_reset(void)
4105 struct ftrace_pid
*fpid
, *safe
;
4107 mutex_lock(&ftrace_lock
);
4108 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
4109 struct pid
*pid
= fpid
->pid
;
4111 clear_ftrace_pid_task(pid
);
4113 list_del(&fpid
->list
);
4117 ftrace_update_pid_func();
4118 ftrace_startup_enable(0);
4120 mutex_unlock(&ftrace_lock
);
4123 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
4125 mutex_lock(&ftrace_lock
);
4127 if (list_empty(&ftrace_pids
) && (!*pos
))
4130 return seq_list_start(&ftrace_pids
, *pos
);
4133 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4138 return seq_list_next(v
, &ftrace_pids
, pos
);
4141 static void fpid_stop(struct seq_file
*m
, void *p
)
4143 mutex_unlock(&ftrace_lock
);
4146 static int fpid_show(struct seq_file
*m
, void *v
)
4148 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
4150 if (v
== (void *)1) {
4151 seq_printf(m
, "no pid\n");
4155 if (fpid
->pid
== ftrace_swapper_pid
)
4156 seq_printf(m
, "swapper tasks\n");
4158 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
4163 static const struct seq_operations ftrace_pid_sops
= {
4164 .start
= fpid_start
,
4171 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
4175 if ((file
->f_mode
& FMODE_WRITE
) &&
4176 (file
->f_flags
& O_TRUNC
))
4179 if (file
->f_mode
& FMODE_READ
)
4180 ret
= seq_open(file
, &ftrace_pid_sops
);
4186 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
4187 size_t cnt
, loff_t
*ppos
)
4193 if (cnt
>= sizeof(buf
))
4196 if (copy_from_user(&buf
, ubuf
, cnt
))
4202 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4203 * to clean the filter quietly.
4205 tmp
= strstrip(buf
);
4206 if (strlen(tmp
) == 0)
4209 ret
= strict_strtol(tmp
, 10, &val
);
4213 ret
= ftrace_pid_add(val
);
4215 return ret
? ret
: cnt
;
4219 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
4221 if (file
->f_mode
& FMODE_READ
)
4222 seq_release(inode
, file
);
4227 static const struct file_operations ftrace_pid_fops
= {
4228 .open
= ftrace_pid_open
,
4229 .write
= ftrace_pid_write
,
4231 .llseek
= seq_lseek
,
4232 .release
= ftrace_pid_release
,
4235 static __init
int ftrace_init_debugfs(void)
4237 struct dentry
*d_tracer
;
4239 d_tracer
= tracing_init_dentry();
4243 ftrace_init_dyn_debugfs(d_tracer
);
4245 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
4246 NULL
, &ftrace_pid_fops
);
4248 ftrace_profile_debugfs(d_tracer
);
4252 fs_initcall(ftrace_init_debugfs
);
4255 * ftrace_kill - kill ftrace
4257 * This function should be used by panic code. It stops ftrace
4258 * but in a not so nice way. If you need to simply kill ftrace
4259 * from a non-atomic section, use ftrace_kill.
4261 void ftrace_kill(void)
4263 ftrace_disabled
= 1;
4265 clear_ftrace_function();
4269 * Test if ftrace is dead or not.
4271 int ftrace_is_dead(void)
4273 return ftrace_disabled
;
4277 * register_ftrace_function - register a function for profiling
4278 * @ops - ops structure that holds the function for profiling.
4280 * Register a function to be called by all functions in the
4283 * Note: @ops->func and all the functions it calls must be labeled
4284 * with "notrace", otherwise it will go into a
4287 int register_ftrace_function(struct ftrace_ops
*ops
)
4291 mutex_lock(&ftrace_lock
);
4293 if (unlikely(ftrace_disabled
))
4296 ret
= __register_ftrace_function(ops
);
4298 ret
= ftrace_startup(ops
, 0);
4302 mutex_unlock(&ftrace_lock
);
4305 EXPORT_SYMBOL_GPL(register_ftrace_function
);
4308 * unregister_ftrace_function - unregister a function for profiling.
4309 * @ops - ops structure that holds the function to unregister
4311 * Unregister a function that was added to be called by ftrace profiling.
4313 int unregister_ftrace_function(struct ftrace_ops
*ops
)
4317 mutex_lock(&ftrace_lock
);
4318 ret
= __unregister_ftrace_function(ops
);
4320 ftrace_shutdown(ops
, 0);
4321 mutex_unlock(&ftrace_lock
);
4325 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
4328 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
4329 void __user
*buffer
, size_t *lenp
,
4334 mutex_lock(&ftrace_lock
);
4336 if (unlikely(ftrace_disabled
))
4339 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
4341 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
4344 last_ftrace_enabled
= !!ftrace_enabled
;
4346 if (ftrace_enabled
) {
4348 ftrace_startup_sysctl();
4350 /* we are starting ftrace again */
4351 if (ftrace_ops_list
!= &ftrace_list_end
) {
4352 if (ftrace_ops_list
->next
== &ftrace_list_end
)
4353 ftrace_trace_function
= ftrace_ops_list
->func
;
4355 ftrace_trace_function
= ftrace_ops_list_func
;
4359 /* stopping ftrace calls (just send to ftrace_stub) */
4360 ftrace_trace_function
= ftrace_stub
;
4362 ftrace_shutdown_sysctl();
4366 mutex_unlock(&ftrace_lock
);
4370 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4372 static int ftrace_graph_active
;
4373 static struct notifier_block ftrace_suspend_notifier
;
4375 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
4380 /* The callbacks that hook a function */
4381 trace_func_graph_ret_t ftrace_graph_return
=
4382 (trace_func_graph_ret_t
)ftrace_stub
;
4383 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
4385 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
4386 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
4390 unsigned long flags
;
4391 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
4392 struct task_struct
*g
, *t
;
4394 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
4395 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
4396 * sizeof(struct ftrace_ret_stack
),
4398 if (!ret_stack_list
[i
]) {
4406 read_lock_irqsave(&tasklist_lock
, flags
);
4407 do_each_thread(g
, t
) {
4413 if (t
->ret_stack
== NULL
) {
4414 atomic_set(&t
->tracing_graph_pause
, 0);
4415 atomic_set(&t
->trace_overrun
, 0);
4416 t
->curr_ret_stack
= -1;
4417 /* Make sure the tasks see the -1 first: */
4419 t
->ret_stack
= ret_stack_list
[start
++];
4421 } while_each_thread(g
, t
);
4424 read_unlock_irqrestore(&tasklist_lock
, flags
);
4426 for (i
= start
; i
< end
; i
++)
4427 kfree(ret_stack_list
[i
]);
4432 ftrace_graph_probe_sched_switch(void *ignore
,
4433 struct task_struct
*prev
, struct task_struct
*next
)
4435 unsigned long long timestamp
;
4439 * Does the user want to count the time a function was asleep.
4440 * If so, do not update the time stamps.
4442 if (trace_flags
& TRACE_ITER_SLEEP_TIME
)
4445 timestamp
= trace_clock_local();
4447 prev
->ftrace_timestamp
= timestamp
;
4449 /* only process tasks that we timestamped */
4450 if (!next
->ftrace_timestamp
)
4454 * Update all the counters in next to make up for the
4455 * time next was sleeping.
4457 timestamp
-= next
->ftrace_timestamp
;
4459 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
4460 next
->ret_stack
[index
].calltime
+= timestamp
;
4463 /* Allocate a return stack for each task */
4464 static int start_graph_tracing(void)
4466 struct ftrace_ret_stack
**ret_stack_list
;
4469 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
4470 sizeof(struct ftrace_ret_stack
*),
4473 if (!ret_stack_list
)
4476 /* The cpu_boot init_task->ret_stack will never be freed */
4477 for_each_online_cpu(cpu
) {
4478 if (!idle_task(cpu
)->ret_stack
)
4479 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
4483 ret
= alloc_retstack_tasklist(ret_stack_list
);
4484 } while (ret
== -EAGAIN
);
4487 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
4489 pr_info("ftrace_graph: Couldn't activate tracepoint"
4490 " probe to kernel_sched_switch\n");
4493 kfree(ret_stack_list
);
4498 * Hibernation protection.
4499 * The state of the current task is too much unstable during
4500 * suspend/restore to disk. We want to protect against that.
4503 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
4507 case PM_HIBERNATION_PREPARE
:
4508 pause_graph_tracing();
4511 case PM_POST_HIBERNATION
:
4512 unpause_graph_tracing();
4518 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
4519 trace_func_graph_ent_t entryfunc
)
4523 mutex_lock(&ftrace_lock
);
4525 /* we currently allow only one tracer registered at a time */
4526 if (ftrace_graph_active
) {
4531 ftrace_suspend_notifier
.notifier_call
= ftrace_suspend_notifier_call
;
4532 register_pm_notifier(&ftrace_suspend_notifier
);
4534 ftrace_graph_active
++;
4535 ret
= start_graph_tracing();
4537 ftrace_graph_active
--;
4541 ftrace_graph_return
= retfunc
;
4542 ftrace_graph_entry
= entryfunc
;
4544 ret
= ftrace_startup(&global_ops
, FTRACE_START_FUNC_RET
);
4547 mutex_unlock(&ftrace_lock
);
4551 void unregister_ftrace_graph(void)
4553 mutex_lock(&ftrace_lock
);
4555 if (unlikely(!ftrace_graph_active
))
4558 ftrace_graph_active
--;
4559 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
4560 ftrace_graph_entry
= ftrace_graph_entry_stub
;
4561 ftrace_shutdown(&global_ops
, FTRACE_STOP_FUNC_RET
);
4562 unregister_pm_notifier(&ftrace_suspend_notifier
);
4563 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
4566 mutex_unlock(&ftrace_lock
);
4569 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
4572 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
4574 atomic_set(&t
->tracing_graph_pause
, 0);
4575 atomic_set(&t
->trace_overrun
, 0);
4576 t
->ftrace_timestamp
= 0;
4577 /* make curr_ret_stack visible before we add the ret_stack */
4579 t
->ret_stack
= ret_stack
;
4583 * Allocate a return stack for the idle task. May be the first
4584 * time through, or it may be done by CPU hotplug online.
4586 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
4588 t
->curr_ret_stack
= -1;
4590 * The idle task has no parent, it either has its own
4591 * stack or no stack at all.
4594 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
4596 if (ftrace_graph_active
) {
4597 struct ftrace_ret_stack
*ret_stack
;
4599 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
4601 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
4602 * sizeof(struct ftrace_ret_stack
),
4606 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
4608 graph_init_task(t
, ret_stack
);
4612 /* Allocate a return stack for newly created task */
4613 void ftrace_graph_init_task(struct task_struct
*t
)
4615 /* Make sure we do not use the parent ret_stack */
4616 t
->ret_stack
= NULL
;
4617 t
->curr_ret_stack
= -1;
4619 if (ftrace_graph_active
) {
4620 struct ftrace_ret_stack
*ret_stack
;
4622 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
4623 * sizeof(struct ftrace_ret_stack
),
4627 graph_init_task(t
, ret_stack
);
4631 void ftrace_graph_exit_task(struct task_struct
*t
)
4633 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
4635 t
->ret_stack
= NULL
;
4636 /* NULL must become visible to IRQs before we free it: */
4642 void ftrace_graph_stop(void)