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 Nadia Yvette Chambers
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 #ifdef CONFIG_DYNAMIC_FTRACE
68 #define INIT_REGEX_LOCK(opsname) \
69 .regex_lock = __MUTEX_INITIALIZER(opsname.regex_lock),
71 #define INIT_REGEX_LOCK(opsname)
74 static struct ftrace_ops ftrace_list_end __read_mostly
= {
76 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_STUB
,
79 /* ftrace_enabled is a method to turn ftrace on or off */
80 int ftrace_enabled __read_mostly
;
81 static int last_ftrace_enabled
;
83 /* Quick disabling of function tracer. */
84 int function_trace_stop __read_mostly
;
86 /* Current function tracing op */
87 struct ftrace_ops
*function_trace_op __read_mostly
= &ftrace_list_end
;
89 /* List for set_ftrace_pid's pids. */
90 LIST_HEAD(ftrace_pids
);
92 struct list_head list
;
97 * ftrace_disabled is set when an anomaly is discovered.
98 * ftrace_disabled is much stronger than ftrace_enabled.
100 static int ftrace_disabled __read_mostly
;
102 static DEFINE_MUTEX(ftrace_lock
);
104 static struct ftrace_ops
*ftrace_global_list __read_mostly
= &ftrace_list_end
;
105 static struct ftrace_ops
*ftrace_control_list __read_mostly
= &ftrace_list_end
;
106 static struct ftrace_ops
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
107 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
108 ftrace_func_t ftrace_pid_function __read_mostly
= ftrace_stub
;
109 static struct ftrace_ops global_ops
;
110 static struct ftrace_ops control_ops
;
112 #if ARCH_SUPPORTS_FTRACE_OPS
113 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
114 struct ftrace_ops
*op
, struct pt_regs
*regs
);
116 /* See comment below, where ftrace_ops_list_func is defined */
117 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
118 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
122 * Traverse the ftrace_global_list, invoking all entries. The reason that we
123 * can use rcu_dereference_raw_notrace() is that elements removed from this list
124 * are simply leaked, so there is no need to interact with a grace-period
125 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
126 * concurrent insertions into the ftrace_global_list.
128 * Silly Alpha and silly pointer-speculation compiler optimizations!
130 #define do_for_each_ftrace_op(op, list) \
131 op = rcu_dereference_raw_notrace(list); \
135 * Optimized for just a single item in the list (as that is the normal case).
137 #define while_for_each_ftrace_op(op) \
138 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
139 unlikely((op) != &ftrace_list_end))
141 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
143 #ifdef CONFIG_DYNAMIC_FTRACE
144 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
145 mutex_init(&ops
->regex_lock
);
146 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
152 * ftrace_nr_registered_ops - return number of ops registered
154 * Returns the number of ftrace_ops registered and tracing functions
156 int ftrace_nr_registered_ops(void)
158 struct ftrace_ops
*ops
;
161 mutex_lock(&ftrace_lock
);
163 for (ops
= ftrace_ops_list
;
164 ops
!= &ftrace_list_end
; ops
= ops
->next
)
167 mutex_unlock(&ftrace_lock
);
173 ftrace_global_list_func(unsigned long ip
, unsigned long parent_ip
,
174 struct ftrace_ops
*op
, struct pt_regs
*regs
)
178 bit
= trace_test_and_set_recursion(TRACE_GLOBAL_START
, TRACE_GLOBAL_MAX
);
182 do_for_each_ftrace_op(op
, ftrace_global_list
) {
183 op
->func(ip
, parent_ip
, op
, regs
);
184 } while_for_each_ftrace_op(op
);
186 trace_clear_recursion(bit
);
189 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
190 struct ftrace_ops
*op
, struct pt_regs
*regs
)
192 if (!test_tsk_trace_trace(current
))
195 ftrace_pid_function(ip
, parent_ip
, op
, regs
);
198 static void set_ftrace_pid_function(ftrace_func_t func
)
200 /* do not set ftrace_pid_function to itself! */
201 if (func
!= ftrace_pid_func
)
202 ftrace_pid_function
= func
;
206 * clear_ftrace_function - reset the ftrace function
208 * This NULLs the ftrace function and in essence stops
209 * tracing. There may be lag
211 void clear_ftrace_function(void)
213 ftrace_trace_function
= ftrace_stub
;
214 ftrace_pid_function
= ftrace_stub
;
217 static void control_ops_disable_all(struct ftrace_ops
*ops
)
221 for_each_possible_cpu(cpu
)
222 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
225 static int control_ops_alloc(struct ftrace_ops
*ops
)
227 int __percpu
*disabled
;
229 disabled
= alloc_percpu(int);
233 ops
->disabled
= disabled
;
234 control_ops_disable_all(ops
);
238 static void control_ops_free(struct ftrace_ops
*ops
)
240 free_percpu(ops
->disabled
);
243 static void update_global_ops(void)
248 * If there's only one function registered, then call that
249 * function directly. Otherwise, we need to iterate over the
250 * registered callers.
252 if (ftrace_global_list
== &ftrace_list_end
||
253 ftrace_global_list
->next
== &ftrace_list_end
) {
254 func
= ftrace_global_list
->func
;
256 * As we are calling the function directly.
257 * If it does not have recursion protection,
258 * the function_trace_op needs to be updated
261 if (ftrace_global_list
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
)
262 global_ops
.flags
|= FTRACE_OPS_FL_RECURSION_SAFE
;
264 global_ops
.flags
&= ~FTRACE_OPS_FL_RECURSION_SAFE
;
266 func
= ftrace_global_list_func
;
267 /* The list has its own recursion protection. */
268 global_ops
.flags
|= FTRACE_OPS_FL_RECURSION_SAFE
;
272 /* If we filter on pids, update to use the pid function */
273 if (!list_empty(&ftrace_pids
)) {
274 set_ftrace_pid_function(func
);
275 func
= ftrace_pid_func
;
278 global_ops
.func
= func
;
281 static void update_ftrace_function(void)
288 * If we are at the end of the list and this ops is
289 * recursion safe and not dynamic and the arch supports passing ops,
290 * then have the mcount trampoline call the function directly.
292 if (ftrace_ops_list
== &ftrace_list_end
||
293 (ftrace_ops_list
->next
== &ftrace_list_end
&&
294 !(ftrace_ops_list
->flags
& FTRACE_OPS_FL_DYNAMIC
) &&
295 (ftrace_ops_list
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) &&
296 !FTRACE_FORCE_LIST_FUNC
)) {
297 /* Set the ftrace_ops that the arch callback uses */
298 if (ftrace_ops_list
== &global_ops
)
299 function_trace_op
= ftrace_global_list
;
301 function_trace_op
= ftrace_ops_list
;
302 func
= ftrace_ops_list
->func
;
304 /* Just use the default ftrace_ops */
305 function_trace_op
= &ftrace_list_end
;
306 func
= ftrace_ops_list_func
;
309 ftrace_trace_function
= func
;
312 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
316 * We are entering ops into the list but another
317 * CPU might be walking that list. We need to make sure
318 * the ops->next pointer is valid before another CPU sees
319 * the ops pointer included into the list.
321 rcu_assign_pointer(*list
, ops
);
324 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
326 struct ftrace_ops
**p
;
329 * If we are removing the last function, then simply point
330 * to the ftrace_stub.
332 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
333 *list
= &ftrace_list_end
;
337 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
348 static void add_ftrace_list_ops(struct ftrace_ops
**list
,
349 struct ftrace_ops
*main_ops
,
350 struct ftrace_ops
*ops
)
352 int first
= *list
== &ftrace_list_end
;
353 add_ftrace_ops(list
, ops
);
355 add_ftrace_ops(&ftrace_ops_list
, main_ops
);
358 static int remove_ftrace_list_ops(struct ftrace_ops
**list
,
359 struct ftrace_ops
*main_ops
,
360 struct ftrace_ops
*ops
)
362 int ret
= remove_ftrace_ops(list
, ops
);
363 if (!ret
&& *list
== &ftrace_list_end
)
364 ret
= remove_ftrace_ops(&ftrace_ops_list
, main_ops
);
368 static int __register_ftrace_function(struct ftrace_ops
*ops
)
370 if (unlikely(ftrace_disabled
))
373 if (FTRACE_WARN_ON(ops
== &global_ops
))
376 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
379 /* We don't support both control and global flags set. */
380 if ((ops
->flags
& FL_GLOBAL_CONTROL_MASK
) == FL_GLOBAL_CONTROL_MASK
)
383 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
385 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
386 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
387 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
389 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
390 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
393 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
394 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
397 if (!core_kernel_data((unsigned long)ops
))
398 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
400 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
401 add_ftrace_list_ops(&ftrace_global_list
, &global_ops
, ops
);
402 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
403 } else if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
404 if (control_ops_alloc(ops
))
406 add_ftrace_list_ops(&ftrace_control_list
, &control_ops
, ops
);
408 add_ftrace_ops(&ftrace_ops_list
, ops
);
411 update_ftrace_function();
416 static void ftrace_sync(struct work_struct
*work
)
419 * This function is just a stub to implement a hard force
420 * of synchronize_sched(). This requires synchronizing
421 * tasks even in userspace and idle.
423 * Yes, function tracing is rude.
427 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
434 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
437 if (FTRACE_WARN_ON(ops
== &global_ops
))
440 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
441 ret
= remove_ftrace_list_ops(&ftrace_global_list
,
444 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
445 } else if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
446 ret
= remove_ftrace_list_ops(&ftrace_control_list
,
450 * The ftrace_ops is now removed from the list,
451 * so there'll be no new users. We must ensure
452 * all current users are done before we free
454 * Note synchronize_sched() is not enough, as we
455 * use preempt_disable() to do RCU, but the function
456 * tracer can be called where RCU is not active
457 * (before user_exit()).
459 schedule_on_each_cpu(ftrace_sync
);
460 control_ops_free(ops
);
463 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
469 update_ftrace_function();
472 * Dynamic ops may be freed, we must make sure that all
473 * callers are done before leaving this function.
475 * Again, normal synchronize_sched() is not good enough.
476 * We need to do a hard force of sched synchronization.
478 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
)
479 schedule_on_each_cpu(ftrace_sync
);
485 static void ftrace_update_pid_func(void)
487 /* Only do something if we are tracing something */
488 if (ftrace_trace_function
== ftrace_stub
)
491 update_ftrace_function();
494 #ifdef CONFIG_FUNCTION_PROFILER
495 struct ftrace_profile
{
496 struct hlist_node node
;
498 unsigned long counter
;
499 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
500 unsigned long long time
;
501 unsigned long long time_squared
;
505 struct ftrace_profile_page
{
506 struct ftrace_profile_page
*next
;
508 struct ftrace_profile records
[];
511 struct ftrace_profile_stat
{
513 struct hlist_head
*hash
;
514 struct ftrace_profile_page
*pages
;
515 struct ftrace_profile_page
*start
;
516 struct tracer_stat stat
;
519 #define PROFILE_RECORDS_SIZE \
520 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
522 #define PROFILES_PER_PAGE \
523 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
525 static int ftrace_profile_enabled __read_mostly
;
527 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
528 static DEFINE_MUTEX(ftrace_profile_lock
);
530 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
532 #define FTRACE_PROFILE_HASH_BITS 10
533 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
536 function_stat_next(void *v
, int idx
)
538 struct ftrace_profile
*rec
= v
;
539 struct ftrace_profile_page
*pg
;
541 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
547 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
551 rec
= &pg
->records
[0];
559 static void *function_stat_start(struct tracer_stat
*trace
)
561 struct ftrace_profile_stat
*stat
=
562 container_of(trace
, struct ftrace_profile_stat
, stat
);
564 if (!stat
|| !stat
->start
)
567 return function_stat_next(&stat
->start
->records
[0], 0);
570 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
571 /* function graph compares on total time */
572 static int function_stat_cmp(void *p1
, void *p2
)
574 struct ftrace_profile
*a
= p1
;
575 struct ftrace_profile
*b
= p2
;
577 if (a
->time
< b
->time
)
579 if (a
->time
> b
->time
)
585 /* not function graph compares against hits */
586 static int function_stat_cmp(void *p1
, void *p2
)
588 struct ftrace_profile
*a
= p1
;
589 struct ftrace_profile
*b
= p2
;
591 if (a
->counter
< b
->counter
)
593 if (a
->counter
> b
->counter
)
600 static int function_stat_headers(struct seq_file
*m
)
602 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
603 seq_printf(m
, " Function "
606 "--- ---- --- ---\n");
608 seq_printf(m
, " Function Hit\n"
614 static int function_stat_show(struct seq_file
*m
, void *v
)
616 struct ftrace_profile
*rec
= v
;
617 char str
[KSYM_SYMBOL_LEN
];
619 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
620 static struct trace_seq s
;
621 unsigned long long avg
;
622 unsigned long long stddev
;
624 mutex_lock(&ftrace_profile_lock
);
626 /* we raced with function_profile_reset() */
627 if (unlikely(rec
->counter
== 0)) {
632 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
633 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
635 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
638 do_div(avg
, rec
->counter
);
640 /* Sample standard deviation (s^2) */
641 if (rec
->counter
<= 1)
645 * Apply Welford's method:
646 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
648 stddev
= rec
->counter
* rec
->time_squared
-
649 rec
->time
* rec
->time
;
652 * Divide only 1000 for ns^2 -> us^2 conversion.
653 * trace_print_graph_duration will divide 1000 again.
655 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
659 trace_print_graph_duration(rec
->time
, &s
);
660 trace_seq_puts(&s
, " ");
661 trace_print_graph_duration(avg
, &s
);
662 trace_seq_puts(&s
, " ");
663 trace_print_graph_duration(stddev
, &s
);
664 trace_print_seq(m
, &s
);
668 mutex_unlock(&ftrace_profile_lock
);
673 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
675 struct ftrace_profile_page
*pg
;
677 pg
= stat
->pages
= stat
->start
;
680 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
685 memset(stat
->hash
, 0,
686 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
689 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
691 struct ftrace_profile_page
*pg
;
696 /* If we already allocated, do nothing */
700 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
704 #ifdef CONFIG_DYNAMIC_FTRACE
705 functions
= ftrace_update_tot_cnt
;
708 * We do not know the number of functions that exist because
709 * dynamic tracing is what counts them. With past experience
710 * we have around 20K functions. That should be more than enough.
711 * It is highly unlikely we will execute every function in
717 pg
= stat
->start
= stat
->pages
;
719 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
721 for (i
= 1; i
< pages
; i
++) {
722 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
733 unsigned long tmp
= (unsigned long)pg
;
745 static int ftrace_profile_init_cpu(int cpu
)
747 struct ftrace_profile_stat
*stat
;
750 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
753 /* If the profile is already created, simply reset it */
754 ftrace_profile_reset(stat
);
759 * We are profiling all functions, but usually only a few thousand
760 * functions are hit. We'll make a hash of 1024 items.
762 size
= FTRACE_PROFILE_HASH_SIZE
;
764 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
769 /* Preallocate the function profiling pages */
770 if (ftrace_profile_pages_init(stat
) < 0) {
779 static int ftrace_profile_init(void)
784 for_each_online_cpu(cpu
) {
785 ret
= ftrace_profile_init_cpu(cpu
);
793 /* interrupts must be disabled */
794 static struct ftrace_profile
*
795 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
797 struct ftrace_profile
*rec
;
798 struct hlist_head
*hhd
;
801 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
802 hhd
= &stat
->hash
[key
];
804 if (hlist_empty(hhd
))
807 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
815 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
816 struct ftrace_profile
*rec
)
820 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
821 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
825 * The memory is already allocated, this simply finds a new record to use.
827 static struct ftrace_profile
*
828 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
830 struct ftrace_profile
*rec
= NULL
;
832 /* prevent recursion (from NMIs) */
833 if (atomic_inc_return(&stat
->disabled
) != 1)
837 * Try to find the function again since an NMI
838 * could have added it
840 rec
= ftrace_find_profiled_func(stat
, ip
);
844 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
845 if (!stat
->pages
->next
)
847 stat
->pages
= stat
->pages
->next
;
850 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
852 ftrace_add_profile(stat
, rec
);
855 atomic_dec(&stat
->disabled
);
861 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
862 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
864 struct ftrace_profile_stat
*stat
;
865 struct ftrace_profile
*rec
;
868 if (!ftrace_profile_enabled
)
871 local_irq_save(flags
);
873 stat
= &__get_cpu_var(ftrace_profile_stats
);
874 if (!stat
->hash
|| !ftrace_profile_enabled
)
877 rec
= ftrace_find_profiled_func(stat
, ip
);
879 rec
= ftrace_profile_alloc(stat
, ip
);
886 local_irq_restore(flags
);
889 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
890 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
892 function_profile_call(trace
->func
, 0, NULL
, NULL
);
896 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
898 struct ftrace_profile_stat
*stat
;
899 unsigned long long calltime
;
900 struct ftrace_profile
*rec
;
903 local_irq_save(flags
);
904 stat
= &__get_cpu_var(ftrace_profile_stats
);
905 if (!stat
->hash
|| !ftrace_profile_enabled
)
908 /* If the calltime was zero'd ignore it */
909 if (!trace
->calltime
)
912 calltime
= trace
->rettime
- trace
->calltime
;
914 if (!(trace_flags
& TRACE_ITER_GRAPH_TIME
)) {
917 index
= trace
->depth
;
919 /* Append this call time to the parent time to subtract */
921 current
->ret_stack
[index
- 1].subtime
+= calltime
;
923 if (current
->ret_stack
[index
].subtime
< calltime
)
924 calltime
-= current
->ret_stack
[index
].subtime
;
929 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
931 rec
->time
+= calltime
;
932 rec
->time_squared
+= calltime
* calltime
;
936 local_irq_restore(flags
);
939 static int register_ftrace_profiler(void)
941 return register_ftrace_graph(&profile_graph_return
,
942 &profile_graph_entry
);
945 static void unregister_ftrace_profiler(void)
947 unregister_ftrace_graph();
950 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
951 .func
= function_profile_call
,
952 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
953 INIT_REGEX_LOCK(ftrace_profile_ops
)
956 static int register_ftrace_profiler(void)
958 return register_ftrace_function(&ftrace_profile_ops
);
961 static void unregister_ftrace_profiler(void)
963 unregister_ftrace_function(&ftrace_profile_ops
);
965 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
968 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
969 size_t cnt
, loff_t
*ppos
)
974 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
980 mutex_lock(&ftrace_profile_lock
);
981 if (ftrace_profile_enabled
^ val
) {
983 ret
= ftrace_profile_init();
989 ret
= register_ftrace_profiler();
994 ftrace_profile_enabled
= 1;
996 ftrace_profile_enabled
= 0;
998 * unregister_ftrace_profiler calls stop_machine
999 * so this acts like an synchronize_sched.
1001 unregister_ftrace_profiler();
1005 mutex_unlock(&ftrace_profile_lock
);
1013 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
1014 size_t cnt
, loff_t
*ppos
)
1016 char buf
[64]; /* big enough to hold a number */
1019 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
1020 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
1023 static const struct file_operations ftrace_profile_fops
= {
1024 .open
= tracing_open_generic
,
1025 .read
= ftrace_profile_read
,
1026 .write
= ftrace_profile_write
,
1027 .llseek
= default_llseek
,
1030 /* used to initialize the real stat files */
1031 static struct tracer_stat function_stats __initdata
= {
1032 .name
= "functions",
1033 .stat_start
= function_stat_start
,
1034 .stat_next
= function_stat_next
,
1035 .stat_cmp
= function_stat_cmp
,
1036 .stat_headers
= function_stat_headers
,
1037 .stat_show
= function_stat_show
1040 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1042 struct ftrace_profile_stat
*stat
;
1043 struct dentry
*entry
;
1048 for_each_possible_cpu(cpu
) {
1049 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1051 /* allocate enough for function name + cpu number */
1052 name
= kmalloc(32, GFP_KERNEL
);
1055 * The files created are permanent, if something happens
1056 * we still do not free memory.
1059 "Could not allocate stat file for cpu %d\n",
1063 stat
->stat
= function_stats
;
1064 snprintf(name
, 32, "function%d", cpu
);
1065 stat
->stat
.name
= name
;
1066 ret
= register_stat_tracer(&stat
->stat
);
1069 "Could not register function stat for cpu %d\n",
1076 entry
= debugfs_create_file("function_profile_enabled", 0644,
1077 d_tracer
, NULL
, &ftrace_profile_fops
);
1079 pr_warning("Could not create debugfs "
1080 "'function_profile_enabled' entry\n");
1083 #else /* CONFIG_FUNCTION_PROFILER */
1084 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1087 #endif /* CONFIG_FUNCTION_PROFILER */
1089 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1092 ftrace_filter_lseek(struct file
*file
, loff_t offset
, int whence
)
1096 if (file
->f_mode
& FMODE_READ
)
1097 ret
= seq_lseek(file
, offset
, whence
);
1099 file
->f_pos
= ret
= 1;
1104 #ifdef CONFIG_DYNAMIC_FTRACE
1106 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1107 # error Dynamic ftrace depends on MCOUNT_RECORD
1110 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1112 struct ftrace_func_probe
{
1113 struct hlist_node node
;
1114 struct ftrace_probe_ops
*ops
;
1115 unsigned long flags
;
1118 struct list_head free_list
;
1121 struct ftrace_func_entry
{
1122 struct hlist_node hlist
;
1126 struct ftrace_hash
{
1127 unsigned long size_bits
;
1128 struct hlist_head
*buckets
;
1129 unsigned long count
;
1130 struct rcu_head rcu
;
1134 * We make these constant because no one should touch them,
1135 * but they are used as the default "empty hash", to avoid allocating
1136 * it all the time. These are in a read only section such that if
1137 * anyone does try to modify it, it will cause an exception.
1139 static const struct hlist_head empty_buckets
[1];
1140 static const struct ftrace_hash empty_hash
= {
1141 .buckets
= (struct hlist_head
*)empty_buckets
,
1143 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1145 static struct ftrace_ops global_ops
= {
1146 .func
= ftrace_stub
,
1147 .notrace_hash
= EMPTY_HASH
,
1148 .filter_hash
= EMPTY_HASH
,
1149 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
1150 INIT_REGEX_LOCK(global_ops
)
1153 struct ftrace_page
{
1154 struct ftrace_page
*next
;
1155 struct dyn_ftrace
*records
;
1160 static struct ftrace_page
*ftrace_new_pgs
;
1162 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1163 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1165 /* estimate from running different kernels */
1166 #define NR_TO_INIT 10000
1168 static struct ftrace_page
*ftrace_pages_start
;
1169 static struct ftrace_page
*ftrace_pages
;
1171 static bool ftrace_hash_empty(struct ftrace_hash
*hash
)
1173 return !hash
|| !hash
->count
;
1176 static struct ftrace_func_entry
*
1177 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1180 struct ftrace_func_entry
*entry
;
1181 struct hlist_head
*hhd
;
1183 if (ftrace_hash_empty(hash
))
1186 if (hash
->size_bits
> 0)
1187 key
= hash_long(ip
, hash
->size_bits
);
1191 hhd
= &hash
->buckets
[key
];
1193 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1194 if (entry
->ip
== ip
)
1200 static void __add_hash_entry(struct ftrace_hash
*hash
,
1201 struct ftrace_func_entry
*entry
)
1203 struct hlist_head
*hhd
;
1206 if (hash
->size_bits
)
1207 key
= hash_long(entry
->ip
, hash
->size_bits
);
1211 hhd
= &hash
->buckets
[key
];
1212 hlist_add_head(&entry
->hlist
, hhd
);
1216 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1218 struct ftrace_func_entry
*entry
;
1220 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1225 __add_hash_entry(hash
, entry
);
1231 free_hash_entry(struct ftrace_hash
*hash
,
1232 struct ftrace_func_entry
*entry
)
1234 hlist_del(&entry
->hlist
);
1240 remove_hash_entry(struct ftrace_hash
*hash
,
1241 struct ftrace_func_entry
*entry
)
1243 hlist_del(&entry
->hlist
);
1247 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1249 struct hlist_head
*hhd
;
1250 struct hlist_node
*tn
;
1251 struct ftrace_func_entry
*entry
;
1252 int size
= 1 << hash
->size_bits
;
1258 for (i
= 0; i
< size
; i
++) {
1259 hhd
= &hash
->buckets
[i
];
1260 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1261 free_hash_entry(hash
, entry
);
1263 FTRACE_WARN_ON(hash
->count
);
1266 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1268 if (!hash
|| hash
== EMPTY_HASH
)
1270 ftrace_hash_clear(hash
);
1271 kfree(hash
->buckets
);
1275 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1277 struct ftrace_hash
*hash
;
1279 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1280 free_ftrace_hash(hash
);
1283 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1285 if (!hash
|| hash
== EMPTY_HASH
)
1287 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1290 void ftrace_free_filter(struct ftrace_ops
*ops
)
1292 ftrace_ops_init(ops
);
1293 free_ftrace_hash(ops
->filter_hash
);
1294 free_ftrace_hash(ops
->notrace_hash
);
1297 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1299 struct ftrace_hash
*hash
;
1302 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1306 size
= 1 << size_bits
;
1307 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1309 if (!hash
->buckets
) {
1314 hash
->size_bits
= size_bits
;
1319 static struct ftrace_hash
*
1320 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1322 struct ftrace_func_entry
*entry
;
1323 struct ftrace_hash
*new_hash
;
1328 new_hash
= alloc_ftrace_hash(size_bits
);
1333 if (ftrace_hash_empty(hash
))
1336 size
= 1 << hash
->size_bits
;
1337 for (i
= 0; i
< size
; i
++) {
1338 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1339 ret
= add_hash_entry(new_hash
, entry
->ip
);
1345 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1350 free_ftrace_hash(new_hash
);
1355 ftrace_hash_rec_disable(struct ftrace_ops
*ops
, int filter_hash
);
1357 ftrace_hash_rec_enable(struct ftrace_ops
*ops
, int filter_hash
);
1360 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1361 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1363 struct ftrace_func_entry
*entry
;
1364 struct hlist_node
*tn
;
1365 struct hlist_head
*hhd
;
1366 struct ftrace_hash
*old_hash
;
1367 struct ftrace_hash
*new_hash
;
1368 int size
= src
->count
;
1374 * Remove the current set, update the hash and add
1377 ftrace_hash_rec_disable(ops
, enable
);
1380 * If the new source is empty, just free dst and assign it
1384 free_ftrace_hash_rcu(*dst
);
1385 rcu_assign_pointer(*dst
, EMPTY_HASH
);
1386 /* still need to update the function records */
1392 * Make the hash size about 1/2 the # found
1394 for (size
/= 2; size
; size
>>= 1)
1397 /* Don't allocate too much */
1398 if (bits
> FTRACE_HASH_MAX_BITS
)
1399 bits
= FTRACE_HASH_MAX_BITS
;
1402 new_hash
= alloc_ftrace_hash(bits
);
1406 size
= 1 << src
->size_bits
;
1407 for (i
= 0; i
< size
; i
++) {
1408 hhd
= &src
->buckets
[i
];
1409 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1410 remove_hash_entry(src
, entry
);
1411 __add_hash_entry(new_hash
, entry
);
1416 rcu_assign_pointer(*dst
, new_hash
);
1417 free_ftrace_hash_rcu(old_hash
);
1422 * Enable regardless of ret:
1423 * On success, we enable the new hash.
1424 * On failure, we re-enable the original hash.
1426 ftrace_hash_rec_enable(ops
, enable
);
1432 * Test the hashes for this ops to see if we want to call
1433 * the ops->func or not.
1435 * It's a match if the ip is in the ops->filter_hash or
1436 * the filter_hash does not exist or is empty,
1438 * the ip is not in the ops->notrace_hash.
1440 * This needs to be called with preemption disabled as
1441 * the hashes are freed with call_rcu_sched().
1444 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1446 struct ftrace_hash
*filter_hash
;
1447 struct ftrace_hash
*notrace_hash
;
1450 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1452 * There's a small race when adding ops that the ftrace handler
1453 * that wants regs, may be called without them. We can not
1454 * allow that handler to be called if regs is NULL.
1456 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1460 filter_hash
= rcu_dereference_raw_notrace(ops
->filter_hash
);
1461 notrace_hash
= rcu_dereference_raw_notrace(ops
->notrace_hash
);
1463 if ((ftrace_hash_empty(filter_hash
) ||
1464 ftrace_lookup_ip(filter_hash
, ip
)) &&
1465 (ftrace_hash_empty(notrace_hash
) ||
1466 !ftrace_lookup_ip(notrace_hash
, ip
)))
1475 * This is a double for. Do not use 'break' to break out of the loop,
1476 * you must use a goto.
1478 #define do_for_each_ftrace_rec(pg, rec) \
1479 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1481 for (_____i = 0; _____i < pg->index; _____i++) { \
1482 rec = &pg->records[_____i];
1484 #define while_for_each_ftrace_rec() \
1489 static int ftrace_cmp_recs(const void *a
, const void *b
)
1491 const struct dyn_ftrace
*key
= a
;
1492 const struct dyn_ftrace
*rec
= b
;
1494 if (key
->flags
< rec
->ip
)
1496 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1501 static unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1503 struct ftrace_page
*pg
;
1504 struct dyn_ftrace
*rec
;
1505 struct dyn_ftrace key
;
1508 key
.flags
= end
; /* overload flags, as it is unsigned long */
1510 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1511 if (end
< pg
->records
[0].ip
||
1512 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1514 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1515 sizeof(struct dyn_ftrace
),
1525 * ftrace_location - return true if the ip giving is a traced location
1526 * @ip: the instruction pointer to check
1528 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1529 * That is, the instruction that is either a NOP or call to
1530 * the function tracer. It checks the ftrace internal tables to
1531 * determine if the address belongs or not.
1533 unsigned long ftrace_location(unsigned long ip
)
1535 return ftrace_location_range(ip
, ip
);
1539 * ftrace_text_reserved - return true if range contains an ftrace location
1540 * @start: start of range to search
1541 * @end: end of range to search (inclusive). @end points to the last byte to check.
1543 * Returns 1 if @start and @end contains a ftrace location.
1544 * That is, the instruction that is either a NOP or call to
1545 * the function tracer. It checks the ftrace internal tables to
1546 * determine if the address belongs or not.
1548 int ftrace_text_reserved(void *start
, void *end
)
1552 ret
= ftrace_location_range((unsigned long)start
,
1553 (unsigned long)end
);
1558 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1562 struct ftrace_hash
*hash
;
1563 struct ftrace_hash
*other_hash
;
1564 struct ftrace_page
*pg
;
1565 struct dyn_ftrace
*rec
;
1569 /* Only update if the ops has been registered */
1570 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1574 * In the filter_hash case:
1575 * If the count is zero, we update all records.
1576 * Otherwise we just update the items in the hash.
1578 * In the notrace_hash case:
1579 * We enable the update in the hash.
1580 * As disabling notrace means enabling the tracing,
1581 * and enabling notrace means disabling, the inc variable
1585 hash
= ops
->filter_hash
;
1586 other_hash
= ops
->notrace_hash
;
1587 if (ftrace_hash_empty(hash
))
1591 hash
= ops
->notrace_hash
;
1592 other_hash
= ops
->filter_hash
;
1594 * If the notrace hash has no items,
1595 * then there's nothing to do.
1597 if (ftrace_hash_empty(hash
))
1601 do_for_each_ftrace_rec(pg
, rec
) {
1602 int in_other_hash
= 0;
1608 * Only the filter_hash affects all records.
1609 * Update if the record is not in the notrace hash.
1611 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1614 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1615 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1620 if (filter_hash
&& in_hash
&& !in_other_hash
)
1622 else if (!filter_hash
&& in_hash
&&
1623 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1631 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == FTRACE_REF_MAX
))
1634 * If any ops wants regs saved for this function
1635 * then all ops will get saved regs.
1637 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1638 rec
->flags
|= FTRACE_FL_REGS
;
1640 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == 0))
1645 /* Shortcut, if we handled all records, we are done. */
1646 if (!all
&& count
== hash
->count
)
1648 } while_for_each_ftrace_rec();
1651 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1654 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1657 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1660 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1663 static void print_ip_ins(const char *fmt
, unsigned char *p
)
1667 printk(KERN_CONT
"%s", fmt
);
1669 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1670 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1674 * ftrace_bug - report and shutdown function tracer
1675 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1676 * @ip: The address that failed
1678 * The arch code that enables or disables the function tracing
1679 * can call ftrace_bug() when it has detected a problem in
1680 * modifying the code. @failed should be one of either:
1681 * EFAULT - if the problem happens on reading the @ip address
1682 * EINVAL - if what is read at @ip is not what was expected
1683 * EPERM - if the problem happens on writting to the @ip address
1685 void ftrace_bug(int failed
, unsigned long ip
)
1689 FTRACE_WARN_ON_ONCE(1);
1690 pr_info("ftrace faulted on modifying ");
1694 FTRACE_WARN_ON_ONCE(1);
1695 pr_info("ftrace failed to modify ");
1697 print_ip_ins(" actual: ", (unsigned char *)ip
);
1698 printk(KERN_CONT
"\n");
1701 FTRACE_WARN_ON_ONCE(1);
1702 pr_info("ftrace faulted on writing ");
1706 FTRACE_WARN_ON_ONCE(1);
1707 pr_info("ftrace faulted on unknown error ");
1712 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
1714 unsigned long flag
= 0UL;
1717 * If we are updating calls:
1719 * If the record has a ref count, then we need to enable it
1720 * because someone is using it.
1722 * Otherwise we make sure its disabled.
1724 * If we are disabling calls, then disable all records that
1727 if (enable
&& (rec
->flags
& ~FTRACE_FL_MASK
))
1728 flag
= FTRACE_FL_ENABLED
;
1731 * If enabling and the REGS flag does not match the REGS_EN, then
1732 * do not ignore this record. Set flags to fail the compare against
1736 (!(rec
->flags
& FTRACE_FL_REGS
) != !(rec
->flags
& FTRACE_FL_REGS_EN
)))
1737 flag
|= FTRACE_FL_REGS
;
1739 /* If the state of this record hasn't changed, then do nothing */
1740 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
1741 return FTRACE_UPDATE_IGNORE
;
1744 /* Save off if rec is being enabled (for return value) */
1745 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
1748 rec
->flags
|= FTRACE_FL_ENABLED
;
1749 if (flag
& FTRACE_FL_REGS
) {
1750 if (rec
->flags
& FTRACE_FL_REGS
)
1751 rec
->flags
|= FTRACE_FL_REGS_EN
;
1753 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
1758 * If this record is being updated from a nop, then
1759 * return UPDATE_MAKE_CALL.
1760 * Otherwise, if the EN flag is set, then return
1761 * UPDATE_MODIFY_CALL_REGS to tell the caller to convert
1762 * from the non-save regs, to a save regs function.
1764 * return UPDATE_MODIFY_CALL to tell the caller to convert
1765 * from the save regs, to a non-save regs function.
1767 if (flag
& FTRACE_FL_ENABLED
)
1768 return FTRACE_UPDATE_MAKE_CALL
;
1769 else if (rec
->flags
& FTRACE_FL_REGS_EN
)
1770 return FTRACE_UPDATE_MODIFY_CALL_REGS
;
1772 return FTRACE_UPDATE_MODIFY_CALL
;
1776 /* If there's no more users, clear all flags */
1777 if (!(rec
->flags
& ~FTRACE_FL_MASK
))
1780 /* Just disable the record (keep REGS state) */
1781 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1784 return FTRACE_UPDATE_MAKE_NOP
;
1788 * ftrace_update_record, set a record that now is tracing or not
1789 * @rec: the record to update
1790 * @enable: set to 1 if the record is tracing, zero to force disable
1792 * The records that represent all functions that can be traced need
1793 * to be updated when tracing has been enabled.
1795 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
1797 return ftrace_check_record(rec
, enable
, 1);
1801 * ftrace_test_record, check if the record has been enabled or not
1802 * @rec: the record to test
1803 * @enable: set to 1 to check if enabled, 0 if it is disabled
1805 * The arch code may need to test if a record is already set to
1806 * tracing to determine how to modify the function code that it
1809 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
1811 return ftrace_check_record(rec
, enable
, 0);
1815 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
1817 unsigned long ftrace_old_addr
;
1818 unsigned long ftrace_addr
;
1821 ret
= ftrace_update_record(rec
, enable
);
1823 if (rec
->flags
& FTRACE_FL_REGS
)
1824 ftrace_addr
= (unsigned long)FTRACE_REGS_ADDR
;
1826 ftrace_addr
= (unsigned long)FTRACE_ADDR
;
1829 case FTRACE_UPDATE_IGNORE
:
1832 case FTRACE_UPDATE_MAKE_CALL
:
1833 return ftrace_make_call(rec
, ftrace_addr
);
1835 case FTRACE_UPDATE_MAKE_NOP
:
1836 return ftrace_make_nop(NULL
, rec
, ftrace_addr
);
1838 case FTRACE_UPDATE_MODIFY_CALL_REGS
:
1839 case FTRACE_UPDATE_MODIFY_CALL
:
1840 if (rec
->flags
& FTRACE_FL_REGS
)
1841 ftrace_old_addr
= (unsigned long)FTRACE_ADDR
;
1843 ftrace_old_addr
= (unsigned long)FTRACE_REGS_ADDR
;
1845 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
1848 return -1; /* unknow ftrace bug */
1851 void __weak
ftrace_replace_code(int enable
)
1853 struct dyn_ftrace
*rec
;
1854 struct ftrace_page
*pg
;
1857 if (unlikely(ftrace_disabled
))
1860 do_for_each_ftrace_rec(pg
, rec
) {
1861 failed
= __ftrace_replace_code(rec
, enable
);
1863 ftrace_bug(failed
, rec
->ip
);
1864 /* Stop processing */
1867 } while_for_each_ftrace_rec();
1870 struct ftrace_rec_iter
{
1871 struct ftrace_page
*pg
;
1876 * ftrace_rec_iter_start, start up iterating over traced functions
1878 * Returns an iterator handle that is used to iterate over all
1879 * the records that represent address locations where functions
1882 * May return NULL if no records are available.
1884 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
1887 * We only use a single iterator.
1888 * Protected by the ftrace_lock mutex.
1890 static struct ftrace_rec_iter ftrace_rec_iter
;
1891 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
1893 iter
->pg
= ftrace_pages_start
;
1896 /* Could have empty pages */
1897 while (iter
->pg
&& !iter
->pg
->index
)
1898 iter
->pg
= iter
->pg
->next
;
1907 * ftrace_rec_iter_next, get the next record to process.
1908 * @iter: The handle to the iterator.
1910 * Returns the next iterator after the given iterator @iter.
1912 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
1916 if (iter
->index
>= iter
->pg
->index
) {
1917 iter
->pg
= iter
->pg
->next
;
1920 /* Could have empty pages */
1921 while (iter
->pg
&& !iter
->pg
->index
)
1922 iter
->pg
= iter
->pg
->next
;
1932 * ftrace_rec_iter_record, get the record at the iterator location
1933 * @iter: The current iterator location
1935 * Returns the record that the current @iter is at.
1937 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
1939 return &iter
->pg
->records
[iter
->index
];
1943 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
1950 if (unlikely(ftrace_disabled
))
1953 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
1955 ftrace_bug(ret
, ip
);
1962 * archs can override this function if they must do something
1963 * before the modifying code is performed.
1965 int __weak
ftrace_arch_code_modify_prepare(void)
1971 * archs can override this function if they must do something
1972 * after the modifying code is performed.
1974 int __weak
ftrace_arch_code_modify_post_process(void)
1979 void ftrace_modify_all_code(int command
)
1981 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
1984 * If the ftrace_caller calls a ftrace_ops func directly,
1985 * we need to make sure that it only traces functions it
1986 * expects to trace. When doing the switch of functions,
1987 * we need to update to the ftrace_ops_list_func first
1988 * before the transition between old and new calls are set,
1989 * as the ftrace_ops_list_func will check the ops hashes
1990 * to make sure the ops are having the right functions
1994 ftrace_update_ftrace_func(ftrace_ops_list_func
);
1996 if (command
& FTRACE_UPDATE_CALLS
)
1997 ftrace_replace_code(1);
1998 else if (command
& FTRACE_DISABLE_CALLS
)
1999 ftrace_replace_code(0);
2001 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
)
2002 ftrace_update_ftrace_func(ftrace_trace_function
);
2004 if (command
& FTRACE_START_FUNC_RET
)
2005 ftrace_enable_ftrace_graph_caller();
2006 else if (command
& FTRACE_STOP_FUNC_RET
)
2007 ftrace_disable_ftrace_graph_caller();
2010 static int __ftrace_modify_code(void *data
)
2012 int *command
= data
;
2014 ftrace_modify_all_code(*command
);
2020 * ftrace_run_stop_machine, go back to the stop machine method
2021 * @command: The command to tell ftrace what to do
2023 * If an arch needs to fall back to the stop machine method, the
2024 * it can call this function.
2026 void ftrace_run_stop_machine(int command
)
2028 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2032 * arch_ftrace_update_code, modify the code to trace or not trace
2033 * @command: The command that needs to be done
2035 * Archs can override this function if it does not need to
2036 * run stop_machine() to modify code.
2038 void __weak
arch_ftrace_update_code(int command
)
2040 ftrace_run_stop_machine(command
);
2043 static void ftrace_run_update_code(int command
)
2047 ret
= ftrace_arch_code_modify_prepare();
2048 FTRACE_WARN_ON(ret
);
2052 * Do not call function tracer while we update the code.
2053 * We are in stop machine.
2055 function_trace_stop
++;
2058 * By default we use stop_machine() to modify the code.
2059 * But archs can do what ever they want as long as it
2060 * is safe. The stop_machine() is the safest, but also
2061 * produces the most overhead.
2063 arch_ftrace_update_code(command
);
2065 function_trace_stop
--;
2067 ret
= ftrace_arch_code_modify_post_process();
2068 FTRACE_WARN_ON(ret
);
2071 static ftrace_func_t saved_ftrace_func
;
2072 static int ftrace_start_up
;
2073 static int global_start_up
;
2075 static void ftrace_startup_enable(int command
)
2077 if (saved_ftrace_func
!= ftrace_trace_function
) {
2078 saved_ftrace_func
= ftrace_trace_function
;
2079 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2082 if (!command
|| !ftrace_enabled
)
2085 ftrace_run_update_code(command
);
2088 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2090 bool hash_enable
= true;
2092 if (unlikely(ftrace_disabled
))
2096 command
|= FTRACE_UPDATE_CALLS
;
2098 /* ops marked global share the filter hashes */
2099 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
2101 /* Don't update hash if global is already set */
2102 if (global_start_up
)
2103 hash_enable
= false;
2107 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
2109 ftrace_hash_rec_enable(ops
, 1);
2111 ftrace_startup_enable(command
);
2116 static void ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2118 bool hash_disable
= true;
2120 if (unlikely(ftrace_disabled
))
2125 * Just warn in case of unbalance, no need to kill ftrace, it's not
2126 * critical but the ftrace_call callers may be never nopped again after
2127 * further ftrace uses.
2129 WARN_ON_ONCE(ftrace_start_up
< 0);
2131 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
2134 WARN_ON_ONCE(global_start_up
< 0);
2135 /* Don't update hash if global still has users */
2136 if (global_start_up
) {
2137 WARN_ON_ONCE(!ftrace_start_up
);
2138 hash_disable
= false;
2143 ftrace_hash_rec_disable(ops
, 1);
2145 if (ops
!= &global_ops
|| !global_start_up
)
2146 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2148 command
|= FTRACE_UPDATE_CALLS
;
2150 if (saved_ftrace_func
!= ftrace_trace_function
) {
2151 saved_ftrace_func
= ftrace_trace_function
;
2152 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2155 if (!command
|| !ftrace_enabled
)
2158 ftrace_run_update_code(command
);
2161 static void ftrace_startup_sysctl(void)
2163 if (unlikely(ftrace_disabled
))
2166 /* Force update next time */
2167 saved_ftrace_func
= NULL
;
2168 /* ftrace_start_up is true if we want ftrace running */
2169 if (ftrace_start_up
)
2170 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
2173 static void ftrace_shutdown_sysctl(void)
2175 if (unlikely(ftrace_disabled
))
2178 /* ftrace_start_up is true if ftrace is running */
2179 if (ftrace_start_up
)
2180 ftrace_run_update_code(FTRACE_DISABLE_CALLS
);
2183 static cycle_t ftrace_update_time
;
2184 static unsigned long ftrace_update_cnt
;
2185 unsigned long ftrace_update_tot_cnt
;
2187 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2190 * Filter_hash being empty will default to trace module.
2191 * But notrace hash requires a test of individual module functions.
2193 return ftrace_hash_empty(ops
->filter_hash
) &&
2194 ftrace_hash_empty(ops
->notrace_hash
);
2198 * Check if the current ops references the record.
2200 * If the ops traces all functions, then it was already accounted for.
2201 * If the ops does not trace the current record function, skip it.
2202 * If the ops ignores the function via notrace filter, skip it.
2205 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2207 /* If ops isn't enabled, ignore it */
2208 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2211 /* If ops traces all mods, we already accounted for it */
2212 if (ops_traces_mod(ops
))
2215 /* The function must be in the filter */
2216 if (!ftrace_hash_empty(ops
->filter_hash
) &&
2217 !ftrace_lookup_ip(ops
->filter_hash
, rec
->ip
))
2220 /* If in notrace hash, we ignore it too */
2221 if (ftrace_lookup_ip(ops
->notrace_hash
, rec
->ip
))
2227 static int referenced_filters(struct dyn_ftrace
*rec
)
2229 struct ftrace_ops
*ops
;
2232 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2233 if (ops_references_rec(ops
, rec
))
2240 static int ftrace_update_code(struct module
*mod
)
2242 struct ftrace_page
*pg
;
2243 struct dyn_ftrace
*p
;
2244 cycle_t start
, stop
;
2245 unsigned long ref
= 0;
2250 * When adding a module, we need to check if tracers are
2251 * currently enabled and if they are set to trace all functions.
2252 * If they are, we need to enable the module functions as well
2253 * as update the reference counts for those function records.
2256 struct ftrace_ops
*ops
;
2258 for (ops
= ftrace_ops_list
;
2259 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2260 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
2261 if (ops_traces_mod(ops
))
2269 start
= ftrace_now(raw_smp_processor_id());
2270 ftrace_update_cnt
= 0;
2272 for (pg
= ftrace_new_pgs
; pg
; pg
= pg
->next
) {
2274 for (i
= 0; i
< pg
->index
; i
++) {
2277 /* If something went wrong, bail without enabling anything */
2278 if (unlikely(ftrace_disabled
))
2281 p
= &pg
->records
[i
];
2283 cnt
+= referenced_filters(p
);
2287 * Do the initial record conversion from mcount jump
2288 * to the NOP instructions.
2290 if (!ftrace_code_disable(mod
, p
))
2293 ftrace_update_cnt
++;
2296 * If the tracing is enabled, go ahead and enable the record.
2298 * The reason not to enable the record immediatelly is the
2299 * inherent check of ftrace_make_nop/ftrace_make_call for
2300 * correct previous instructions. Making first the NOP
2301 * conversion puts the module to the correct state, thus
2302 * passing the ftrace_make_call check.
2304 if (ftrace_start_up
&& cnt
) {
2305 int failed
= __ftrace_replace_code(p
, 1);
2307 ftrace_bug(failed
, p
->ip
);
2312 ftrace_new_pgs
= NULL
;
2314 stop
= ftrace_now(raw_smp_processor_id());
2315 ftrace_update_time
= stop
- start
;
2316 ftrace_update_tot_cnt
+= ftrace_update_cnt
;
2321 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2326 if (WARN_ON(!count
))
2329 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2332 * We want to fill as much as possible. No more than a page
2335 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2339 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2342 /* if we can't allocate this size, try something smaller */
2349 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2358 static struct ftrace_page
*
2359 ftrace_allocate_pages(unsigned long num_to_init
)
2361 struct ftrace_page
*start_pg
;
2362 struct ftrace_page
*pg
;
2369 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2374 * Try to allocate as much as possible in one continues
2375 * location that fills in all of the space. We want to
2376 * waste as little space as possible.
2379 cnt
= ftrace_allocate_records(pg
, num_to_init
);
2387 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2398 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
2399 free_pages((unsigned long)pg
->records
, order
);
2400 start_pg
= pg
->next
;
2404 pr_info("ftrace: FAILED to allocate memory for functions\n");
2408 static int __init
ftrace_dyn_table_alloc(unsigned long num_to_init
)
2413 pr_info("ftrace: No functions to be traced?\n");
2417 cnt
= num_to_init
/ ENTRIES_PER_PAGE
;
2418 pr_info("ftrace: allocating %ld entries in %d pages\n",
2419 num_to_init
, cnt
+ 1);
2424 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2426 struct ftrace_iterator
{
2429 struct ftrace_page
*pg
;
2430 struct dyn_ftrace
*func
;
2431 struct ftrace_func_probe
*probe
;
2432 struct trace_parser parser
;
2433 struct ftrace_hash
*hash
;
2434 struct ftrace_ops
*ops
;
2441 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
2443 struct ftrace_iterator
*iter
= m
->private;
2444 struct hlist_node
*hnd
= NULL
;
2445 struct hlist_head
*hhd
;
2451 hnd
= &iter
->probe
->node
;
2453 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
2456 hhd
= &ftrace_func_hash
[iter
->hidx
];
2458 if (hlist_empty(hhd
)) {
2474 if (WARN_ON_ONCE(!hnd
))
2477 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
2482 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
2484 struct ftrace_iterator
*iter
= m
->private;
2488 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
2491 if (iter
->func_pos
> *pos
)
2495 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
2496 p
= t_hash_next(m
, &l
);
2503 /* Only set this if we have an item */
2504 iter
->flags
|= FTRACE_ITER_HASH
;
2510 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
2512 struct ftrace_func_probe
*rec
;
2515 if (WARN_ON_ONCE(!rec
))
2518 if (rec
->ops
->print
)
2519 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
2521 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
2524 seq_printf(m
, ":%p", rec
->data
);
2531 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2533 struct ftrace_iterator
*iter
= m
->private;
2534 struct ftrace_ops
*ops
= iter
->ops
;
2535 struct dyn_ftrace
*rec
= NULL
;
2537 if (unlikely(ftrace_disabled
))
2540 if (iter
->flags
& FTRACE_ITER_HASH
)
2541 return t_hash_next(m
, pos
);
2544 iter
->pos
= iter
->func_pos
= *pos
;
2546 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
2547 return t_hash_start(m
, pos
);
2550 if (iter
->idx
>= iter
->pg
->index
) {
2551 if (iter
->pg
->next
) {
2552 iter
->pg
= iter
->pg
->next
;
2557 rec
= &iter
->pg
->records
[iter
->idx
++];
2558 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
2559 !(ftrace_lookup_ip(ops
->filter_hash
, rec
->ip
))) ||
2561 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
2562 !ftrace_lookup_ip(ops
->notrace_hash
, rec
->ip
)) ||
2564 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
2565 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
2573 return t_hash_start(m
, pos
);
2580 static void reset_iter_read(struct ftrace_iterator
*iter
)
2584 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
2587 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2589 struct ftrace_iterator
*iter
= m
->private;
2590 struct ftrace_ops
*ops
= iter
->ops
;
2594 mutex_lock(&ftrace_lock
);
2596 if (unlikely(ftrace_disabled
))
2600 * If an lseek was done, then reset and start from beginning.
2602 if (*pos
< iter
->pos
)
2603 reset_iter_read(iter
);
2606 * For set_ftrace_filter reading, if we have the filter
2607 * off, we can short cut and just print out that all
2608 * functions are enabled.
2610 if (iter
->flags
& FTRACE_ITER_FILTER
&&
2611 ftrace_hash_empty(ops
->filter_hash
)) {
2613 return t_hash_start(m
, pos
);
2614 iter
->flags
|= FTRACE_ITER_PRINTALL
;
2615 /* reset in case of seek/pread */
2616 iter
->flags
&= ~FTRACE_ITER_HASH
;
2620 if (iter
->flags
& FTRACE_ITER_HASH
)
2621 return t_hash_start(m
, pos
);
2624 * Unfortunately, we need to restart at ftrace_pages_start
2625 * every time we let go of the ftrace_mutex. This is because
2626 * those pointers can change without the lock.
2628 iter
->pg
= ftrace_pages_start
;
2630 for (l
= 0; l
<= *pos
; ) {
2631 p
= t_next(m
, p
, &l
);
2637 return t_hash_start(m
, pos
);
2642 static void t_stop(struct seq_file
*m
, void *p
)
2644 mutex_unlock(&ftrace_lock
);
2647 static int t_show(struct seq_file
*m
, void *v
)
2649 struct ftrace_iterator
*iter
= m
->private;
2650 struct dyn_ftrace
*rec
;
2652 if (iter
->flags
& FTRACE_ITER_HASH
)
2653 return t_hash_show(m
, iter
);
2655 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
2656 seq_printf(m
, "#### all functions enabled ####\n");
2665 seq_printf(m
, "%ps", (void *)rec
->ip
);
2666 if (iter
->flags
& FTRACE_ITER_ENABLED
)
2667 seq_printf(m
, " (%ld)%s",
2668 rec
->flags
& ~FTRACE_FL_MASK
,
2669 rec
->flags
& FTRACE_FL_REGS
? " R" : "");
2670 seq_printf(m
, "\n");
2675 static const struct seq_operations show_ftrace_seq_ops
= {
2683 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
2685 struct ftrace_iterator
*iter
;
2687 if (unlikely(ftrace_disabled
))
2690 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2692 iter
->pg
= ftrace_pages_start
;
2693 iter
->ops
= &global_ops
;
2696 return iter
? 0 : -ENOMEM
;
2700 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
2702 struct ftrace_iterator
*iter
;
2704 if (unlikely(ftrace_disabled
))
2707 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2709 iter
->pg
= ftrace_pages_start
;
2710 iter
->flags
= FTRACE_ITER_ENABLED
;
2711 iter
->ops
= &global_ops
;
2714 return iter
? 0 : -ENOMEM
;
2717 static void ftrace_filter_reset(struct ftrace_hash
*hash
)
2719 mutex_lock(&ftrace_lock
);
2720 ftrace_hash_clear(hash
);
2721 mutex_unlock(&ftrace_lock
);
2725 * ftrace_regex_open - initialize function tracer filter files
2726 * @ops: The ftrace_ops that hold the hash filters
2727 * @flag: The type of filter to process
2728 * @inode: The inode, usually passed in to your open routine
2729 * @file: The file, usually passed in to your open routine
2731 * ftrace_regex_open() initializes the filter files for the
2732 * @ops. Depending on @flag it may process the filter hash or
2733 * the notrace hash of @ops. With this called from the open
2734 * routine, you can use ftrace_filter_write() for the write
2735 * routine if @flag has FTRACE_ITER_FILTER set, or
2736 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2737 * ftrace_filter_lseek() should be used as the lseek routine, and
2738 * release must call ftrace_regex_release().
2741 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
2742 struct inode
*inode
, struct file
*file
)
2744 struct ftrace_iterator
*iter
;
2745 struct ftrace_hash
*hash
;
2748 ftrace_ops_init(ops
);
2750 if (unlikely(ftrace_disabled
))
2753 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2757 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
2765 mutex_lock(&ops
->regex_lock
);
2767 if (flag
& FTRACE_ITER_NOTRACE
)
2768 hash
= ops
->notrace_hash
;
2770 hash
= ops
->filter_hash
;
2772 if (file
->f_mode
& FMODE_WRITE
) {
2773 iter
->hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, hash
);
2775 trace_parser_put(&iter
->parser
);
2782 if ((file
->f_mode
& FMODE_WRITE
) &&
2783 (file
->f_flags
& O_TRUNC
))
2784 ftrace_filter_reset(iter
->hash
);
2786 if (file
->f_mode
& FMODE_READ
) {
2787 iter
->pg
= ftrace_pages_start
;
2789 ret
= seq_open(file
, &show_ftrace_seq_ops
);
2791 struct seq_file
*m
= file
->private_data
;
2795 free_ftrace_hash(iter
->hash
);
2796 trace_parser_put(&iter
->parser
);
2800 file
->private_data
= iter
;
2803 mutex_unlock(&ops
->regex_lock
);
2809 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
2811 return ftrace_regex_open(&global_ops
,
2812 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
2817 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
2819 return ftrace_regex_open(&global_ops
, FTRACE_ITER_NOTRACE
,
2823 static int ftrace_match(char *str
, char *regex
, int len
, int type
)
2830 if (strcmp(str
, regex
) == 0)
2833 case MATCH_FRONT_ONLY
:
2834 if (strncmp(str
, regex
, len
) == 0)
2837 case MATCH_MIDDLE_ONLY
:
2838 if (strstr(str
, regex
))
2841 case MATCH_END_ONLY
:
2843 if (slen
>= len
&& memcmp(str
+ slen
- len
, regex
, len
) == 0)
2852 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int not)
2854 struct ftrace_func_entry
*entry
;
2857 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
2859 /* Do nothing if it doesn't exist */
2863 free_hash_entry(hash
, entry
);
2865 /* Do nothing if it exists */
2869 ret
= add_hash_entry(hash
, rec
->ip
);
2875 ftrace_match_record(struct dyn_ftrace
*rec
, char *mod
,
2876 char *regex
, int len
, int type
)
2878 char str
[KSYM_SYMBOL_LEN
];
2881 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
2884 /* module lookup requires matching the module */
2885 if (!modname
|| strcmp(modname
, mod
))
2888 /* blank search means to match all funcs in the mod */
2893 return ftrace_match(str
, regex
, len
, type
);
2897 match_records(struct ftrace_hash
*hash
, char *buff
,
2898 int len
, char *mod
, int not)
2900 unsigned search_len
= 0;
2901 struct ftrace_page
*pg
;
2902 struct dyn_ftrace
*rec
;
2903 int type
= MATCH_FULL
;
2904 char *search
= buff
;
2909 type
= filter_parse_regex(buff
, len
, &search
, ¬);
2910 search_len
= strlen(search
);
2913 mutex_lock(&ftrace_lock
);
2915 if (unlikely(ftrace_disabled
))
2918 do_for_each_ftrace_rec(pg
, rec
) {
2919 if (ftrace_match_record(rec
, mod
, search
, search_len
, type
)) {
2920 ret
= enter_record(hash
, rec
, not);
2927 } while_for_each_ftrace_rec();
2929 mutex_unlock(&ftrace_lock
);
2935 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
2937 return match_records(hash
, buff
, len
, NULL
, 0);
2941 ftrace_match_module_records(struct ftrace_hash
*hash
, char *buff
, char *mod
)
2945 /* blank or '*' mean the same */
2946 if (strcmp(buff
, "*") == 0)
2949 /* handle the case of 'dont filter this module' */
2950 if (strcmp(buff
, "!") == 0 || strcmp(buff
, "!*") == 0) {
2955 return match_records(hash
, buff
, strlen(buff
), mod
, not);
2959 * We register the module command as a template to show others how
2960 * to register the a command as well.
2964 ftrace_mod_callback(struct ftrace_hash
*hash
,
2965 char *func
, char *cmd
, char *param
, int enable
)
2971 * cmd == 'mod' because we only registered this func
2972 * for the 'mod' ftrace_func_command.
2973 * But if you register one func with multiple commands,
2974 * you can tell which command was used by the cmd
2978 /* we must have a module name */
2982 mod
= strsep(¶m
, ":");
2986 ret
= ftrace_match_module_records(hash
, func
, mod
);
2995 static struct ftrace_func_command ftrace_mod_cmd
= {
2997 .func
= ftrace_mod_callback
,
3000 static int __init
ftrace_mod_cmd_init(void)
3002 return register_ftrace_command(&ftrace_mod_cmd
);
3004 core_initcall(ftrace_mod_cmd_init
);
3006 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
3007 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3009 struct ftrace_func_probe
*entry
;
3010 struct hlist_head
*hhd
;
3013 key
= hash_long(ip
, FTRACE_HASH_BITS
);
3015 hhd
= &ftrace_func_hash
[key
];
3017 if (hlist_empty(hhd
))
3021 * Disable preemption for these calls to prevent a RCU grace
3022 * period. This syncs the hash iteration and freeing of items
3023 * on the hash. rcu_read_lock is too dangerous here.
3025 preempt_disable_notrace();
3026 hlist_for_each_entry_rcu_notrace(entry
, hhd
, node
) {
3027 if (entry
->ip
== ip
)
3028 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
3030 preempt_enable_notrace();
3033 static struct ftrace_ops trace_probe_ops __read_mostly
=
3035 .func
= function_trace_probe_call
,
3036 .flags
= FTRACE_OPS_FL_INITIALIZED
,
3037 INIT_REGEX_LOCK(trace_probe_ops
)
3040 static int ftrace_probe_registered
;
3042 static void __enable_ftrace_function_probe(void)
3047 if (ftrace_probe_registered
) {
3048 /* still need to update the function call sites */
3050 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3054 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3055 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3059 /* Nothing registered? */
3060 if (i
== FTRACE_FUNC_HASHSIZE
)
3063 ret
= __register_ftrace_function(&trace_probe_ops
);
3065 ret
= ftrace_startup(&trace_probe_ops
, 0);
3067 ftrace_probe_registered
= 1;
3070 static void __disable_ftrace_function_probe(void)
3075 if (!ftrace_probe_registered
)
3078 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3079 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3084 /* no more funcs left */
3085 ret
= __unregister_ftrace_function(&trace_probe_ops
);
3087 ftrace_shutdown(&trace_probe_ops
, 0);
3089 ftrace_probe_registered
= 0;
3093 static void ftrace_free_entry(struct ftrace_func_probe
*entry
)
3095 if (entry
->ops
->free
)
3096 entry
->ops
->free(entry
->ops
, entry
->ip
, &entry
->data
);
3101 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3104 struct ftrace_func_probe
*entry
;
3105 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.filter_hash
;
3106 struct ftrace_hash
*hash
;
3107 struct ftrace_page
*pg
;
3108 struct dyn_ftrace
*rec
;
3115 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3116 len
= strlen(search
);
3118 /* we do not support '!' for function probes */
3122 mutex_lock(&trace_probe_ops
.regex_lock
);
3124 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3130 if (unlikely(ftrace_disabled
)) {
3135 mutex_lock(&ftrace_lock
);
3137 do_for_each_ftrace_rec(pg
, rec
) {
3139 if (!ftrace_match_record(rec
, NULL
, search
, len
, type
))
3142 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3144 /* If we did not process any, then return error */
3155 * The caller might want to do something special
3156 * for each function we find. We call the callback
3157 * to give the caller an opportunity to do so.
3160 if (ops
->init(ops
, rec
->ip
, &entry
->data
) < 0) {
3161 /* caller does not like this func */
3167 ret
= enter_record(hash
, rec
, 0);
3175 entry
->ip
= rec
->ip
;
3177 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3178 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3180 } while_for_each_ftrace_rec();
3182 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3186 __enable_ftrace_function_probe();
3189 mutex_unlock(&ftrace_lock
);
3191 mutex_unlock(&trace_probe_ops
.regex_lock
);
3192 free_ftrace_hash(hash
);
3198 PROBE_TEST_FUNC
= 1,
3203 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3204 void *data
, int flags
)
3206 struct ftrace_func_entry
*rec_entry
;
3207 struct ftrace_func_probe
*entry
;
3208 struct ftrace_func_probe
*p
;
3209 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.filter_hash
;
3210 struct list_head free_list
;
3211 struct ftrace_hash
*hash
;
3212 struct hlist_node
*tmp
;
3213 char str
[KSYM_SYMBOL_LEN
];
3214 int type
= MATCH_FULL
;
3218 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3223 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3224 len
= strlen(search
);
3226 /* we do not support '!' for function probes */
3231 mutex_lock(&trace_probe_ops
.regex_lock
);
3233 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3235 /* Hmm, should report this somehow */
3238 INIT_LIST_HEAD(&free_list
);
3240 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3241 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3243 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3245 /* break up if statements for readability */
3246 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3249 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3252 /* do this last, since it is the most expensive */
3254 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3256 if (!ftrace_match(str
, glob
, len
, type
))
3260 rec_entry
= ftrace_lookup_ip(hash
, entry
->ip
);
3261 /* It is possible more than one entry had this ip */
3263 free_hash_entry(hash
, rec_entry
);
3265 hlist_del_rcu(&entry
->node
);
3266 list_add(&entry
->free_list
, &free_list
);
3269 mutex_lock(&ftrace_lock
);
3270 __disable_ftrace_function_probe();
3272 * Remove after the disable is called. Otherwise, if the last
3273 * probe is removed, a null hash means *all enabled*.
3275 ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3276 synchronize_sched();
3277 list_for_each_entry_safe(entry
, p
, &free_list
, free_list
) {
3278 list_del(&entry
->free_list
);
3279 ftrace_free_entry(entry
);
3281 mutex_unlock(&ftrace_lock
);
3284 mutex_unlock(&trace_probe_ops
.regex_lock
);
3285 free_ftrace_hash(hash
);
3289 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3292 __unregister_ftrace_function_probe(glob
, ops
, data
,
3293 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3297 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3299 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3302 void unregister_ftrace_function_probe_all(char *glob
)
3304 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3307 static LIST_HEAD(ftrace_commands
);
3308 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3311 * Currently we only register ftrace commands from __init, so mark this
3314 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
3316 struct ftrace_func_command
*p
;
3319 mutex_lock(&ftrace_cmd_mutex
);
3320 list_for_each_entry(p
, &ftrace_commands
, list
) {
3321 if (strcmp(cmd
->name
, p
->name
) == 0) {
3326 list_add(&cmd
->list
, &ftrace_commands
);
3328 mutex_unlock(&ftrace_cmd_mutex
);
3334 * Currently we only unregister ftrace commands from __init, so mark
3337 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
3339 struct ftrace_func_command
*p
, *n
;
3342 mutex_lock(&ftrace_cmd_mutex
);
3343 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
3344 if (strcmp(cmd
->name
, p
->name
) == 0) {
3346 list_del_init(&p
->list
);
3351 mutex_unlock(&ftrace_cmd_mutex
);
3356 static int ftrace_process_regex(struct ftrace_hash
*hash
,
3357 char *buff
, int len
, int enable
)
3359 char *func
, *command
, *next
= buff
;
3360 struct ftrace_func_command
*p
;
3363 func
= strsep(&next
, ":");
3366 ret
= ftrace_match_records(hash
, func
, len
);
3376 command
= strsep(&next
, ":");
3378 mutex_lock(&ftrace_cmd_mutex
);
3379 list_for_each_entry(p
, &ftrace_commands
, list
) {
3380 if (strcmp(p
->name
, command
) == 0) {
3381 ret
= p
->func(hash
, func
, command
, next
, enable
);
3386 mutex_unlock(&ftrace_cmd_mutex
);
3392 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
3393 size_t cnt
, loff_t
*ppos
, int enable
)
3395 struct ftrace_iterator
*iter
;
3396 struct trace_parser
*parser
;
3402 if (file
->f_mode
& FMODE_READ
) {
3403 struct seq_file
*m
= file
->private_data
;
3406 iter
= file
->private_data
;
3408 if (unlikely(ftrace_disabled
))
3411 /* iter->hash is a local copy, so we don't need regex_lock */
3413 parser
= &iter
->parser
;
3414 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
3416 if (read
>= 0 && trace_parser_loaded(parser
) &&
3417 !trace_parser_cont(parser
)) {
3418 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
3419 parser
->idx
, enable
);
3420 trace_parser_clear(parser
);
3431 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
3432 size_t cnt
, loff_t
*ppos
)
3434 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
3438 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
3439 size_t cnt
, loff_t
*ppos
)
3441 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
3445 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
3447 struct ftrace_func_entry
*entry
;
3449 if (!ftrace_location(ip
))
3453 entry
= ftrace_lookup_ip(hash
, ip
);
3456 free_hash_entry(hash
, entry
);
3460 return add_hash_entry(hash
, ip
);
3463 static void ftrace_ops_update_code(struct ftrace_ops
*ops
)
3465 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
&& ftrace_enabled
)
3466 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3470 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3471 unsigned long ip
, int remove
, int reset
, int enable
)
3473 struct ftrace_hash
**orig_hash
;
3474 struct ftrace_hash
*hash
;
3477 /* All global ops uses the global ops filters */
3478 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
)
3481 if (unlikely(ftrace_disabled
))
3484 mutex_lock(&ops
->regex_lock
);
3487 orig_hash
= &ops
->filter_hash
;
3489 orig_hash
= &ops
->notrace_hash
;
3491 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3494 goto out_regex_unlock
;
3498 ftrace_filter_reset(hash
);
3499 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
3501 goto out_regex_unlock
;
3504 ret
= ftrace_match_addr(hash
, ip
, remove
);
3506 goto out_regex_unlock
;
3509 mutex_lock(&ftrace_lock
);
3510 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3512 ftrace_ops_update_code(ops
);
3514 mutex_unlock(&ftrace_lock
);
3517 mutex_unlock(&ops
->regex_lock
);
3519 free_ftrace_hash(hash
);
3524 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
3525 int reset
, int enable
)
3527 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
3531 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3532 * @ops - the ops to set the filter with
3533 * @ip - the address to add to or remove from the filter.
3534 * @remove - non zero to remove the ip from the filter
3535 * @reset - non zero to reset all filters before applying this filter.
3537 * Filters denote which functions should be enabled when tracing is enabled
3538 * If @ip is NULL, it failes to update filter.
3540 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
3541 int remove
, int reset
)
3543 ftrace_ops_init(ops
);
3544 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
3546 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
3549 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3550 int reset
, int enable
)
3552 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
3556 * ftrace_set_filter - set a function to filter on in ftrace
3557 * @ops - the ops to set the filter with
3558 * @buf - the string that holds the function filter text.
3559 * @len - the length of the string.
3560 * @reset - non zero to reset all filters before applying this filter.
3562 * Filters denote which functions should be enabled when tracing is enabled.
3563 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3565 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
3568 ftrace_ops_init(ops
);
3569 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
3571 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
3574 * ftrace_set_notrace - set a function to not trace in ftrace
3575 * @ops - the ops to set the notrace filter with
3576 * @buf - the string that holds the function notrace text.
3577 * @len - the length of the string.
3578 * @reset - non zero to reset all filters before applying this filter.
3580 * Notrace Filters denote which functions should not be enabled when tracing
3581 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3584 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
3587 ftrace_ops_init(ops
);
3588 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
3590 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
3592 * ftrace_set_filter - set a function to filter on in ftrace
3593 * @ops - the ops to set the filter with
3594 * @buf - the string that holds the function filter text.
3595 * @len - the length of the string.
3596 * @reset - non zero to reset all filters before applying this filter.
3598 * Filters denote which functions should be enabled when tracing is enabled.
3599 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3601 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
3603 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
3605 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
3608 * ftrace_set_notrace - set a function to not trace in ftrace
3609 * @ops - the ops to set the notrace filter with
3610 * @buf - the string that holds the function notrace text.
3611 * @len - the length of the string.
3612 * @reset - non zero to reset all filters before applying this filter.
3614 * Notrace Filters denote which functions should not be enabled when tracing
3615 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3618 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
3620 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
3622 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
3625 * command line interface to allow users to set filters on boot up.
3627 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3628 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3629 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3631 /* Used by function selftest to not test if filter is set */
3632 bool ftrace_filter_param __initdata
;
3634 static int __init
set_ftrace_notrace(char *str
)
3636 ftrace_filter_param
= true;
3637 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
3640 __setup("ftrace_notrace=", set_ftrace_notrace
);
3642 static int __init
set_ftrace_filter(char *str
)
3644 ftrace_filter_param
= true;
3645 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
3648 __setup("ftrace_filter=", set_ftrace_filter
);
3650 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3651 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3652 static int ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
);
3654 static int __init
set_graph_function(char *str
)
3656 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
3659 __setup("ftrace_graph_filter=", set_graph_function
);
3661 static void __init
set_ftrace_early_graph(char *buf
)
3667 func
= strsep(&buf
, ",");
3668 /* we allow only one expression at a time */
3669 ret
= ftrace_set_func(ftrace_graph_funcs
, &ftrace_graph_count
,
3670 FTRACE_GRAPH_MAX_FUNCS
, func
);
3672 printk(KERN_DEBUG
"ftrace: function %s not "
3673 "traceable\n", func
);
3676 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3679 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
3683 ftrace_ops_init(ops
);
3686 func
= strsep(&buf
, ",");
3687 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
3691 static void __init
set_ftrace_early_filters(void)
3693 if (ftrace_filter_buf
[0])
3694 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
3695 if (ftrace_notrace_buf
[0])
3696 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
3697 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3698 if (ftrace_graph_buf
[0])
3699 set_ftrace_early_graph(ftrace_graph_buf
);
3700 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3703 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
3705 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
3706 struct ftrace_iterator
*iter
;
3707 struct ftrace_hash
**orig_hash
;
3708 struct trace_parser
*parser
;
3712 if (file
->f_mode
& FMODE_READ
) {
3714 seq_release(inode
, file
);
3716 iter
= file
->private_data
;
3718 parser
= &iter
->parser
;
3719 if (trace_parser_loaded(parser
)) {
3720 parser
->buffer
[parser
->idx
] = 0;
3721 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
3724 trace_parser_put(parser
);
3726 mutex_lock(&iter
->ops
->regex_lock
);
3728 if (file
->f_mode
& FMODE_WRITE
) {
3729 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
3732 orig_hash
= &iter
->ops
->filter_hash
;
3734 orig_hash
= &iter
->ops
->notrace_hash
;
3736 mutex_lock(&ftrace_lock
);
3737 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
3738 orig_hash
, iter
->hash
);
3740 ftrace_ops_update_code(iter
->ops
);
3742 mutex_unlock(&ftrace_lock
);
3745 mutex_unlock(&iter
->ops
->regex_lock
);
3746 free_ftrace_hash(iter
->hash
);
3752 static const struct file_operations ftrace_avail_fops
= {
3753 .open
= ftrace_avail_open
,
3755 .llseek
= seq_lseek
,
3756 .release
= seq_release_private
,
3759 static const struct file_operations ftrace_enabled_fops
= {
3760 .open
= ftrace_enabled_open
,
3762 .llseek
= seq_lseek
,
3763 .release
= seq_release_private
,
3766 static const struct file_operations ftrace_filter_fops
= {
3767 .open
= ftrace_filter_open
,
3769 .write
= ftrace_filter_write
,
3770 .llseek
= ftrace_filter_lseek
,
3771 .release
= ftrace_regex_release
,
3774 static const struct file_operations ftrace_notrace_fops
= {
3775 .open
= ftrace_notrace_open
,
3777 .write
= ftrace_notrace_write
,
3778 .llseek
= ftrace_filter_lseek
,
3779 .release
= ftrace_regex_release
,
3782 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3784 static DEFINE_MUTEX(graph_lock
);
3786 int ftrace_graph_count
;
3787 int ftrace_graph_notrace_count
;
3788 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
3789 unsigned long ftrace_graph_notrace_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
3791 struct ftrace_graph_data
{
3792 unsigned long *table
;
3795 const struct seq_operations
*seq_ops
;
3799 __g_next(struct seq_file
*m
, loff_t
*pos
)
3801 struct ftrace_graph_data
*fgd
= m
->private;
3803 if (*pos
>= *fgd
->count
)
3805 return &fgd
->table
[*pos
];
3809 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3812 return __g_next(m
, pos
);
3815 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
3817 struct ftrace_graph_data
*fgd
= m
->private;
3819 mutex_lock(&graph_lock
);
3821 /* Nothing, tell g_show to print all functions are enabled */
3822 if (!*fgd
->count
&& !*pos
)
3825 return __g_next(m
, pos
);
3828 static void g_stop(struct seq_file
*m
, void *p
)
3830 mutex_unlock(&graph_lock
);
3833 static int g_show(struct seq_file
*m
, void *v
)
3835 unsigned long *ptr
= v
;
3840 if (ptr
== (unsigned long *)1) {
3841 seq_printf(m
, "#### all functions enabled ####\n");
3845 seq_printf(m
, "%ps\n", (void *)*ptr
);
3850 static const struct seq_operations ftrace_graph_seq_ops
= {
3858 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
3859 struct ftrace_graph_data
*fgd
)
3863 mutex_lock(&graph_lock
);
3864 if ((file
->f_mode
& FMODE_WRITE
) &&
3865 (file
->f_flags
& O_TRUNC
)) {
3867 memset(fgd
->table
, 0, fgd
->size
* sizeof(*fgd
->table
));
3869 mutex_unlock(&graph_lock
);
3871 if (file
->f_mode
& FMODE_READ
) {
3872 ret
= seq_open(file
, fgd
->seq_ops
);
3874 struct seq_file
*m
= file
->private_data
;
3878 file
->private_data
= fgd
;
3884 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
3886 struct ftrace_graph_data
*fgd
;
3888 if (unlikely(ftrace_disabled
))
3891 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
3895 fgd
->table
= ftrace_graph_funcs
;
3896 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
3897 fgd
->count
= &ftrace_graph_count
;
3898 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
3900 return __ftrace_graph_open(inode
, file
, fgd
);
3904 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
3906 struct ftrace_graph_data
*fgd
;
3908 if (unlikely(ftrace_disabled
))
3911 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
3915 fgd
->table
= ftrace_graph_notrace_funcs
;
3916 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
3917 fgd
->count
= &ftrace_graph_notrace_count
;
3918 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
3920 return __ftrace_graph_open(inode
, file
, fgd
);
3924 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
3926 if (file
->f_mode
& FMODE_READ
) {
3927 struct seq_file
*m
= file
->private_data
;
3930 seq_release(inode
, file
);
3932 kfree(file
->private_data
);
3939 ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
)
3941 struct dyn_ftrace
*rec
;
3942 struct ftrace_page
*pg
;
3951 type
= filter_parse_regex(buffer
, strlen(buffer
), &search
, ¬);
3952 if (!not && *idx
>= size
)
3955 search_len
= strlen(search
);
3957 mutex_lock(&ftrace_lock
);
3959 if (unlikely(ftrace_disabled
)) {
3960 mutex_unlock(&ftrace_lock
);
3964 do_for_each_ftrace_rec(pg
, rec
) {
3966 if (ftrace_match_record(rec
, NULL
, search
, search_len
, type
)) {
3967 /* if it is in the array */
3969 for (i
= 0; i
< *idx
; i
++) {
3970 if (array
[i
] == rec
->ip
) {
3979 array
[(*idx
)++] = rec
->ip
;
3985 array
[i
] = array
[--(*idx
)];
3991 } while_for_each_ftrace_rec();
3993 mutex_unlock(&ftrace_lock
);
4002 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
4003 size_t cnt
, loff_t
*ppos
)
4005 struct trace_parser parser
;
4006 ssize_t read
, ret
= 0;
4007 struct ftrace_graph_data
*fgd
= file
->private_data
;
4012 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
))
4015 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
4017 if (read
>= 0 && trace_parser_loaded((&parser
))) {
4018 parser
.buffer
[parser
.idx
] = 0;
4020 mutex_lock(&graph_lock
);
4022 /* we allow only one expression at a time */
4023 ret
= ftrace_set_func(fgd
->table
, fgd
->count
, fgd
->size
,
4026 mutex_unlock(&graph_lock
);
4032 trace_parser_put(&parser
);
4037 static const struct file_operations ftrace_graph_fops
= {
4038 .open
= ftrace_graph_open
,
4040 .write
= ftrace_graph_write
,
4041 .llseek
= ftrace_filter_lseek
,
4042 .release
= ftrace_graph_release
,
4045 static const struct file_operations ftrace_graph_notrace_fops
= {
4046 .open
= ftrace_graph_notrace_open
,
4048 .write
= ftrace_graph_write
,
4049 .llseek
= ftrace_filter_lseek
,
4050 .release
= ftrace_graph_release
,
4052 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4054 static __init
int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
)
4057 trace_create_file("available_filter_functions", 0444,
4058 d_tracer
, NULL
, &ftrace_avail_fops
);
4060 trace_create_file("enabled_functions", 0444,
4061 d_tracer
, NULL
, &ftrace_enabled_fops
);
4063 trace_create_file("set_ftrace_filter", 0644, d_tracer
,
4064 NULL
, &ftrace_filter_fops
);
4066 trace_create_file("set_ftrace_notrace", 0644, d_tracer
,
4067 NULL
, &ftrace_notrace_fops
);
4069 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4070 trace_create_file("set_graph_function", 0444, d_tracer
,
4072 &ftrace_graph_fops
);
4073 trace_create_file("set_graph_notrace", 0444, d_tracer
,
4075 &ftrace_graph_notrace_fops
);
4076 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4081 static int ftrace_cmp_ips(const void *a
, const void *b
)
4083 const unsigned long *ipa
= a
;
4084 const unsigned long *ipb
= b
;
4093 static void ftrace_swap_ips(void *a
, void *b
, int size
)
4095 unsigned long *ipa
= a
;
4096 unsigned long *ipb
= b
;
4104 static int ftrace_process_locs(struct module
*mod
,
4105 unsigned long *start
,
4108 struct ftrace_page
*start_pg
;
4109 struct ftrace_page
*pg
;
4110 struct dyn_ftrace
*rec
;
4111 unsigned long count
;
4114 unsigned long flags
= 0; /* Shut up gcc */
4117 count
= end
- start
;
4122 sort(start
, count
, sizeof(*start
),
4123 ftrace_cmp_ips
, ftrace_swap_ips
);
4125 start_pg
= ftrace_allocate_pages(count
);
4129 mutex_lock(&ftrace_lock
);
4132 * Core and each module needs their own pages, as
4133 * modules will free them when they are removed.
4134 * Force a new page to be allocated for modules.
4137 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
4138 /* First initialization */
4139 ftrace_pages
= ftrace_pages_start
= start_pg
;
4144 if (WARN_ON(ftrace_pages
->next
)) {
4145 /* Hmm, we have free pages? */
4146 while (ftrace_pages
->next
)
4147 ftrace_pages
= ftrace_pages
->next
;
4150 ftrace_pages
->next
= start_pg
;
4156 addr
= ftrace_call_adjust(*p
++);
4158 * Some architecture linkers will pad between
4159 * the different mcount_loc sections of different
4160 * object files to satisfy alignments.
4161 * Skip any NULL pointers.
4166 if (pg
->index
== pg
->size
) {
4167 /* We should have allocated enough */
4168 if (WARN_ON(!pg
->next
))
4173 rec
= &pg
->records
[pg
->index
++];
4177 /* We should have used all pages */
4180 /* Assign the last page to ftrace_pages */
4183 /* These new locations need to be initialized */
4184 ftrace_new_pgs
= start_pg
;
4187 * We only need to disable interrupts on start up
4188 * because we are modifying code that an interrupt
4189 * may execute, and the modification is not atomic.
4190 * But for modules, nothing runs the code we modify
4191 * until we are finished with it, and there's no
4192 * reason to cause large interrupt latencies while we do it.
4195 local_irq_save(flags
);
4196 ftrace_update_code(mod
);
4198 local_irq_restore(flags
);
4201 mutex_unlock(&ftrace_lock
);
4206 #ifdef CONFIG_MODULES
4208 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4210 void ftrace_release_mod(struct module
*mod
)
4212 struct dyn_ftrace
*rec
;
4213 struct ftrace_page
**last_pg
;
4214 struct ftrace_page
*pg
;
4217 mutex_lock(&ftrace_lock
);
4219 if (ftrace_disabled
)
4223 * Each module has its own ftrace_pages, remove
4224 * them from the list.
4226 last_pg
= &ftrace_pages_start
;
4227 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
4228 rec
= &pg
->records
[0];
4229 if (within_module_core(rec
->ip
, mod
)) {
4231 * As core pages are first, the first
4232 * page should never be a module page.
4234 if (WARN_ON(pg
== ftrace_pages_start
))
4237 /* Check if we are deleting the last page */
4238 if (pg
== ftrace_pages
)
4239 ftrace_pages
= next_to_ftrace_page(last_pg
);
4241 *last_pg
= pg
->next
;
4242 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
4243 free_pages((unsigned long)pg
->records
, order
);
4246 last_pg
= &pg
->next
;
4249 mutex_unlock(&ftrace_lock
);
4252 static void ftrace_init_module(struct module
*mod
,
4253 unsigned long *start
, unsigned long *end
)
4255 if (ftrace_disabled
|| start
== end
)
4257 ftrace_process_locs(mod
, start
, end
);
4260 static int ftrace_module_notify_enter(struct notifier_block
*self
,
4261 unsigned long val
, void *data
)
4263 struct module
*mod
= data
;
4265 if (val
== MODULE_STATE_COMING
)
4266 ftrace_init_module(mod
, mod
->ftrace_callsites
,
4267 mod
->ftrace_callsites
+
4268 mod
->num_ftrace_callsites
);
4272 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4273 unsigned long val
, void *data
)
4275 struct module
*mod
= data
;
4277 if (val
== MODULE_STATE_GOING
)
4278 ftrace_release_mod(mod
);
4283 static int ftrace_module_notify_enter(struct notifier_block
*self
,
4284 unsigned long val
, void *data
)
4288 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4289 unsigned long val
, void *data
)
4293 #endif /* CONFIG_MODULES */
4295 struct notifier_block ftrace_module_enter_nb
= {
4296 .notifier_call
= ftrace_module_notify_enter
,
4297 .priority
= INT_MAX
, /* Run before anything that can use kprobes */
4300 struct notifier_block ftrace_module_exit_nb
= {
4301 .notifier_call
= ftrace_module_notify_exit
,
4302 .priority
= INT_MIN
, /* Run after anything that can remove kprobes */
4305 extern unsigned long __start_mcount_loc
[];
4306 extern unsigned long __stop_mcount_loc
[];
4308 void __init
ftrace_init(void)
4310 unsigned long count
, addr
, flags
;
4313 /* Keep the ftrace pointer to the stub */
4314 addr
= (unsigned long)ftrace_stub
;
4316 local_irq_save(flags
);
4317 ftrace_dyn_arch_init(&addr
);
4318 local_irq_restore(flags
);
4320 /* ftrace_dyn_arch_init places the return code in addr */
4324 count
= __stop_mcount_loc
- __start_mcount_loc
;
4326 ret
= ftrace_dyn_table_alloc(count
);
4330 last_ftrace_enabled
= ftrace_enabled
= 1;
4332 ret
= ftrace_process_locs(NULL
,
4336 ret
= register_module_notifier(&ftrace_module_enter_nb
);
4338 pr_warning("Failed to register trace ftrace module enter notifier\n");
4340 ret
= register_module_notifier(&ftrace_module_exit_nb
);
4342 pr_warning("Failed to register trace ftrace module exit notifier\n");
4344 set_ftrace_early_filters();
4348 ftrace_disabled
= 1;
4353 static struct ftrace_ops global_ops
= {
4354 .func
= ftrace_stub
,
4355 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4356 INIT_REGEX_LOCK(global_ops
)
4359 static int __init
ftrace_nodyn_init(void)
4364 core_initcall(ftrace_nodyn_init
);
4366 static inline int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
) { return 0; }
4367 static inline void ftrace_startup_enable(int command
) { }
4368 /* Keep as macros so we do not need to define the commands */
4369 # define ftrace_startup(ops, command) \
4371 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4374 # define ftrace_shutdown(ops, command) do { } while (0)
4375 # define ftrace_startup_sysctl() do { } while (0)
4376 # define ftrace_shutdown_sysctl() do { } while (0)
4379 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
4384 #endif /* CONFIG_DYNAMIC_FTRACE */
4387 ftrace_ops_control_func(unsigned long ip
, unsigned long parent_ip
,
4388 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4390 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT
)))
4394 * Some of the ops may be dynamically allocated,
4395 * they must be freed after a synchronize_sched().
4397 preempt_disable_notrace();
4398 trace_recursion_set(TRACE_CONTROL_BIT
);
4401 * Control funcs (perf) uses RCU. Only trace if
4402 * RCU is currently active.
4404 if (!rcu_is_watching())
4407 do_for_each_ftrace_op(op
, ftrace_control_list
) {
4408 if (!(op
->flags
& FTRACE_OPS_FL_STUB
) &&
4409 !ftrace_function_local_disabled(op
) &&
4410 ftrace_ops_test(op
, ip
, regs
))
4411 op
->func(ip
, parent_ip
, op
, regs
);
4412 } while_for_each_ftrace_op(op
);
4414 trace_recursion_clear(TRACE_CONTROL_BIT
);
4415 preempt_enable_notrace();
4418 static struct ftrace_ops control_ops
= {
4419 .func
= ftrace_ops_control_func
,
4420 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4421 INIT_REGEX_LOCK(control_ops
)
4425 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4426 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
4428 struct ftrace_ops
*op
;
4431 if (function_trace_stop
)
4434 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
4439 * Some of the ops may be dynamically allocated,
4440 * they must be freed after a synchronize_sched().
4442 preempt_disable_notrace();
4443 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4444 if (ftrace_ops_test(op
, ip
, regs
))
4445 op
->func(ip
, parent_ip
, op
, regs
);
4446 } while_for_each_ftrace_op(op
);
4447 preempt_enable_notrace();
4448 trace_clear_recursion(bit
);
4452 * Some archs only support passing ip and parent_ip. Even though
4453 * the list function ignores the op parameter, we do not want any
4454 * C side effects, where a function is called without the caller
4455 * sending a third parameter.
4456 * Archs are to support both the regs and ftrace_ops at the same time.
4457 * If they support ftrace_ops, it is assumed they support regs.
4458 * If call backs want to use regs, they must either check for regs
4459 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4460 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4461 * An architecture can pass partial regs with ftrace_ops and still
4462 * set the ARCH_SUPPORT_FTARCE_OPS.
4464 #if ARCH_SUPPORTS_FTRACE_OPS
4465 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4466 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4468 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
4471 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
4473 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
4477 static void clear_ftrace_swapper(void)
4479 struct task_struct
*p
;
4483 for_each_online_cpu(cpu
) {
4485 clear_tsk_trace_trace(p
);
4490 static void set_ftrace_swapper(void)
4492 struct task_struct
*p
;
4496 for_each_online_cpu(cpu
) {
4498 set_tsk_trace_trace(p
);
4503 static void clear_ftrace_pid(struct pid
*pid
)
4505 struct task_struct
*p
;
4508 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4509 clear_tsk_trace_trace(p
);
4510 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4516 static void set_ftrace_pid(struct pid
*pid
)
4518 struct task_struct
*p
;
4521 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4522 set_tsk_trace_trace(p
);
4523 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4527 static void clear_ftrace_pid_task(struct pid
*pid
)
4529 if (pid
== ftrace_swapper_pid
)
4530 clear_ftrace_swapper();
4532 clear_ftrace_pid(pid
);
4535 static void set_ftrace_pid_task(struct pid
*pid
)
4537 if (pid
== ftrace_swapper_pid
)
4538 set_ftrace_swapper();
4540 set_ftrace_pid(pid
);
4543 static int ftrace_pid_add(int p
)
4546 struct ftrace_pid
*fpid
;
4549 mutex_lock(&ftrace_lock
);
4552 pid
= ftrace_swapper_pid
;
4554 pid
= find_get_pid(p
);
4561 list_for_each_entry(fpid
, &ftrace_pids
, list
)
4562 if (fpid
->pid
== pid
)
4567 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
4571 list_add(&fpid
->list
, &ftrace_pids
);
4574 set_ftrace_pid_task(pid
);
4576 ftrace_update_pid_func();
4577 ftrace_startup_enable(0);
4579 mutex_unlock(&ftrace_lock
);
4583 if (pid
!= ftrace_swapper_pid
)
4587 mutex_unlock(&ftrace_lock
);
4591 static void ftrace_pid_reset(void)
4593 struct ftrace_pid
*fpid
, *safe
;
4595 mutex_lock(&ftrace_lock
);
4596 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
4597 struct pid
*pid
= fpid
->pid
;
4599 clear_ftrace_pid_task(pid
);
4601 list_del(&fpid
->list
);
4605 ftrace_update_pid_func();
4606 ftrace_startup_enable(0);
4608 mutex_unlock(&ftrace_lock
);
4611 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
4613 mutex_lock(&ftrace_lock
);
4615 if (list_empty(&ftrace_pids
) && (!*pos
))
4618 return seq_list_start(&ftrace_pids
, *pos
);
4621 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4626 return seq_list_next(v
, &ftrace_pids
, pos
);
4629 static void fpid_stop(struct seq_file
*m
, void *p
)
4631 mutex_unlock(&ftrace_lock
);
4634 static int fpid_show(struct seq_file
*m
, void *v
)
4636 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
4638 if (v
== (void *)1) {
4639 seq_printf(m
, "no pid\n");
4643 if (fpid
->pid
== ftrace_swapper_pid
)
4644 seq_printf(m
, "swapper tasks\n");
4646 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
4651 static const struct seq_operations ftrace_pid_sops
= {
4652 .start
= fpid_start
,
4659 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
4663 if ((file
->f_mode
& FMODE_WRITE
) &&
4664 (file
->f_flags
& O_TRUNC
))
4667 if (file
->f_mode
& FMODE_READ
)
4668 ret
= seq_open(file
, &ftrace_pid_sops
);
4674 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
4675 size_t cnt
, loff_t
*ppos
)
4681 if (cnt
>= sizeof(buf
))
4684 if (copy_from_user(&buf
, ubuf
, cnt
))
4690 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4691 * to clean the filter quietly.
4693 tmp
= strstrip(buf
);
4694 if (strlen(tmp
) == 0)
4697 ret
= kstrtol(tmp
, 10, &val
);
4701 ret
= ftrace_pid_add(val
);
4703 return ret
? ret
: cnt
;
4707 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
4709 if (file
->f_mode
& FMODE_READ
)
4710 seq_release(inode
, file
);
4715 static const struct file_operations ftrace_pid_fops
= {
4716 .open
= ftrace_pid_open
,
4717 .write
= ftrace_pid_write
,
4719 .llseek
= ftrace_filter_lseek
,
4720 .release
= ftrace_pid_release
,
4723 static __init
int ftrace_init_debugfs(void)
4725 struct dentry
*d_tracer
;
4727 d_tracer
= tracing_init_dentry();
4731 ftrace_init_dyn_debugfs(d_tracer
);
4733 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
4734 NULL
, &ftrace_pid_fops
);
4736 ftrace_profile_debugfs(d_tracer
);
4740 fs_initcall(ftrace_init_debugfs
);
4743 * ftrace_kill - kill ftrace
4745 * This function should be used by panic code. It stops ftrace
4746 * but in a not so nice way. If you need to simply kill ftrace
4747 * from a non-atomic section, use ftrace_kill.
4749 void ftrace_kill(void)
4751 ftrace_disabled
= 1;
4753 clear_ftrace_function();
4757 * Test if ftrace is dead or not.
4759 int ftrace_is_dead(void)
4761 return ftrace_disabled
;
4765 * register_ftrace_function - register a function for profiling
4766 * @ops - ops structure that holds the function for profiling.
4768 * Register a function to be called by all functions in the
4771 * Note: @ops->func and all the functions it calls must be labeled
4772 * with "notrace", otherwise it will go into a
4775 int register_ftrace_function(struct ftrace_ops
*ops
)
4779 ftrace_ops_init(ops
);
4781 mutex_lock(&ftrace_lock
);
4783 ret
= __register_ftrace_function(ops
);
4785 ret
= ftrace_startup(ops
, 0);
4787 mutex_unlock(&ftrace_lock
);
4791 EXPORT_SYMBOL_GPL(register_ftrace_function
);
4794 * unregister_ftrace_function - unregister a function for profiling.
4795 * @ops - ops structure that holds the function to unregister
4797 * Unregister a function that was added to be called by ftrace profiling.
4799 int unregister_ftrace_function(struct ftrace_ops
*ops
)
4803 mutex_lock(&ftrace_lock
);
4804 ret
= __unregister_ftrace_function(ops
);
4806 ftrace_shutdown(ops
, 0);
4807 mutex_unlock(&ftrace_lock
);
4811 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
4814 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
4815 void __user
*buffer
, size_t *lenp
,
4820 mutex_lock(&ftrace_lock
);
4822 if (unlikely(ftrace_disabled
))
4825 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
4827 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
4830 last_ftrace_enabled
= !!ftrace_enabled
;
4832 if (ftrace_enabled
) {
4834 ftrace_startup_sysctl();
4836 /* we are starting ftrace again */
4837 if (ftrace_ops_list
!= &ftrace_list_end
)
4838 update_ftrace_function();
4841 /* stopping ftrace calls (just send to ftrace_stub) */
4842 ftrace_trace_function
= ftrace_stub
;
4844 ftrace_shutdown_sysctl();
4848 mutex_unlock(&ftrace_lock
);
4852 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4854 static int ftrace_graph_active
;
4855 static struct notifier_block ftrace_suspend_notifier
;
4857 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
4862 /* The callbacks that hook a function */
4863 trace_func_graph_ret_t ftrace_graph_return
=
4864 (trace_func_graph_ret_t
)ftrace_stub
;
4865 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
4867 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
4868 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
4872 unsigned long flags
;
4873 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
4874 struct task_struct
*g
, *t
;
4876 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
4877 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
4878 * sizeof(struct ftrace_ret_stack
),
4880 if (!ret_stack_list
[i
]) {
4888 read_lock_irqsave(&tasklist_lock
, flags
);
4889 do_each_thread(g
, t
) {
4895 if (t
->ret_stack
== NULL
) {
4896 atomic_set(&t
->tracing_graph_pause
, 0);
4897 atomic_set(&t
->trace_overrun
, 0);
4898 t
->curr_ret_stack
= -1;
4899 /* Make sure the tasks see the -1 first: */
4901 t
->ret_stack
= ret_stack_list
[start
++];
4903 } while_each_thread(g
, t
);
4906 read_unlock_irqrestore(&tasklist_lock
, flags
);
4908 for (i
= start
; i
< end
; i
++)
4909 kfree(ret_stack_list
[i
]);
4914 ftrace_graph_probe_sched_switch(void *ignore
,
4915 struct task_struct
*prev
, struct task_struct
*next
)
4917 unsigned long long timestamp
;
4921 * Does the user want to count the time a function was asleep.
4922 * If so, do not update the time stamps.
4924 if (trace_flags
& TRACE_ITER_SLEEP_TIME
)
4927 timestamp
= trace_clock_local();
4929 prev
->ftrace_timestamp
= timestamp
;
4931 /* only process tasks that we timestamped */
4932 if (!next
->ftrace_timestamp
)
4936 * Update all the counters in next to make up for the
4937 * time next was sleeping.
4939 timestamp
-= next
->ftrace_timestamp
;
4941 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
4942 next
->ret_stack
[index
].calltime
+= timestamp
;
4945 /* Allocate a return stack for each task */
4946 static int start_graph_tracing(void)
4948 struct ftrace_ret_stack
**ret_stack_list
;
4951 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
4952 sizeof(struct ftrace_ret_stack
*),
4955 if (!ret_stack_list
)
4958 /* The cpu_boot init_task->ret_stack will never be freed */
4959 for_each_online_cpu(cpu
) {
4960 if (!idle_task(cpu
)->ret_stack
)
4961 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
4965 ret
= alloc_retstack_tasklist(ret_stack_list
);
4966 } while (ret
== -EAGAIN
);
4969 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
4971 pr_info("ftrace_graph: Couldn't activate tracepoint"
4972 " probe to kernel_sched_switch\n");
4975 kfree(ret_stack_list
);
4980 * Hibernation protection.
4981 * The state of the current task is too much unstable during
4982 * suspend/restore to disk. We want to protect against that.
4985 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
4989 case PM_HIBERNATION_PREPARE
:
4990 pause_graph_tracing();
4993 case PM_POST_HIBERNATION
:
4994 unpause_graph_tracing();
5000 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
5001 trace_func_graph_ent_t entryfunc
)
5005 mutex_lock(&ftrace_lock
);
5007 /* we currently allow only one tracer registered at a time */
5008 if (ftrace_graph_active
) {
5013 ftrace_suspend_notifier
.notifier_call
= ftrace_suspend_notifier_call
;
5014 register_pm_notifier(&ftrace_suspend_notifier
);
5016 ftrace_graph_active
++;
5017 ret
= start_graph_tracing();
5019 ftrace_graph_active
--;
5023 ftrace_graph_return
= retfunc
;
5024 ftrace_graph_entry
= entryfunc
;
5026 ret
= ftrace_startup(&global_ops
, FTRACE_START_FUNC_RET
);
5029 mutex_unlock(&ftrace_lock
);
5033 void unregister_ftrace_graph(void)
5035 mutex_lock(&ftrace_lock
);
5037 if (unlikely(!ftrace_graph_active
))
5040 ftrace_graph_active
--;
5041 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
5042 ftrace_graph_entry
= ftrace_graph_entry_stub
;
5043 ftrace_shutdown(&global_ops
, FTRACE_STOP_FUNC_RET
);
5044 unregister_pm_notifier(&ftrace_suspend_notifier
);
5045 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5048 mutex_unlock(&ftrace_lock
);
5051 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
5054 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
5056 atomic_set(&t
->tracing_graph_pause
, 0);
5057 atomic_set(&t
->trace_overrun
, 0);
5058 t
->ftrace_timestamp
= 0;
5059 /* make curr_ret_stack visible before we add the ret_stack */
5061 t
->ret_stack
= ret_stack
;
5065 * Allocate a return stack for the idle task. May be the first
5066 * time through, or it may be done by CPU hotplug online.
5068 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
5070 t
->curr_ret_stack
= -1;
5072 * The idle task has no parent, it either has its own
5073 * stack or no stack at all.
5076 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
5078 if (ftrace_graph_active
) {
5079 struct ftrace_ret_stack
*ret_stack
;
5081 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
5083 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5084 * sizeof(struct ftrace_ret_stack
),
5088 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
5090 graph_init_task(t
, ret_stack
);
5094 /* Allocate a return stack for newly created task */
5095 void ftrace_graph_init_task(struct task_struct
*t
)
5097 /* Make sure we do not use the parent ret_stack */
5098 t
->ret_stack
= NULL
;
5099 t
->curr_ret_stack
= -1;
5101 if (ftrace_graph_active
) {
5102 struct ftrace_ret_stack
*ret_stack
;
5104 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5105 * sizeof(struct ftrace_ret_stack
),
5109 graph_init_task(t
, ret_stack
);
5113 void ftrace_graph_exit_task(struct task_struct
*t
)
5115 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
5117 t
->ret_stack
= NULL
;
5118 /* NULL must become visible to IRQs before we free it: */
5124 void ftrace_graph_stop(void)