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() 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() 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(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((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 int __unregister_ftrace_function(struct ftrace_ops
*ops
)
423 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
426 if (FTRACE_WARN_ON(ops
== &global_ops
))
429 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
430 ret
= remove_ftrace_list_ops(&ftrace_global_list
,
433 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
434 } else if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
435 ret
= remove_ftrace_list_ops(&ftrace_control_list
,
439 * The ftrace_ops is now removed from the list,
440 * so there'll be no new users. We must ensure
441 * all current users are done before we free
445 control_ops_free(ops
);
448 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
454 update_ftrace_function();
457 * Dynamic ops may be freed, we must make sure that all
458 * callers are done before leaving this function.
460 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
)
466 static void ftrace_update_pid_func(void)
468 /* Only do something if we are tracing something */
469 if (ftrace_trace_function
== ftrace_stub
)
472 update_ftrace_function();
475 #ifdef CONFIG_FUNCTION_PROFILER
476 struct ftrace_profile
{
477 struct hlist_node node
;
479 unsigned long counter
;
480 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
481 unsigned long long time
;
482 unsigned long long time_squared
;
486 struct ftrace_profile_page
{
487 struct ftrace_profile_page
*next
;
489 struct ftrace_profile records
[];
492 struct ftrace_profile_stat
{
494 struct hlist_head
*hash
;
495 struct ftrace_profile_page
*pages
;
496 struct ftrace_profile_page
*start
;
497 struct tracer_stat stat
;
500 #define PROFILE_RECORDS_SIZE \
501 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
503 #define PROFILES_PER_PAGE \
504 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
506 static int ftrace_profile_enabled __read_mostly
;
508 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
509 static DEFINE_MUTEX(ftrace_profile_lock
);
511 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
513 #define FTRACE_PROFILE_HASH_BITS 10
514 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
517 function_stat_next(void *v
, int idx
)
519 struct ftrace_profile
*rec
= v
;
520 struct ftrace_profile_page
*pg
;
522 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
528 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
532 rec
= &pg
->records
[0];
540 static void *function_stat_start(struct tracer_stat
*trace
)
542 struct ftrace_profile_stat
*stat
=
543 container_of(trace
, struct ftrace_profile_stat
, stat
);
545 if (!stat
|| !stat
->start
)
548 return function_stat_next(&stat
->start
->records
[0], 0);
551 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
552 /* function graph compares on total time */
553 static int function_stat_cmp(void *p1
, void *p2
)
555 struct ftrace_profile
*a
= p1
;
556 struct ftrace_profile
*b
= p2
;
558 if (a
->time
< b
->time
)
560 if (a
->time
> b
->time
)
566 /* not function graph compares against hits */
567 static int function_stat_cmp(void *p1
, void *p2
)
569 struct ftrace_profile
*a
= p1
;
570 struct ftrace_profile
*b
= p2
;
572 if (a
->counter
< b
->counter
)
574 if (a
->counter
> b
->counter
)
581 static int function_stat_headers(struct seq_file
*m
)
583 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
584 seq_printf(m
, " Function "
587 "--- ---- --- ---\n");
589 seq_printf(m
, " Function Hit\n"
595 static int function_stat_show(struct seq_file
*m
, void *v
)
597 struct ftrace_profile
*rec
= v
;
598 char str
[KSYM_SYMBOL_LEN
];
600 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
601 static struct trace_seq s
;
602 unsigned long long avg
;
603 unsigned long long stddev
;
605 mutex_lock(&ftrace_profile_lock
);
607 /* we raced with function_profile_reset() */
608 if (unlikely(rec
->counter
== 0)) {
613 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
614 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
616 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
619 do_div(avg
, rec
->counter
);
621 /* Sample standard deviation (s^2) */
622 if (rec
->counter
<= 1)
625 stddev
= rec
->time_squared
- rec
->counter
* avg
* avg
;
627 * Divide only 1000 for ns^2 -> us^2 conversion.
628 * trace_print_graph_duration will divide 1000 again.
630 do_div(stddev
, (rec
->counter
- 1) * 1000);
634 trace_print_graph_duration(rec
->time
, &s
);
635 trace_seq_puts(&s
, " ");
636 trace_print_graph_duration(avg
, &s
);
637 trace_seq_puts(&s
, " ");
638 trace_print_graph_duration(stddev
, &s
);
639 trace_print_seq(m
, &s
);
643 mutex_unlock(&ftrace_profile_lock
);
648 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
650 struct ftrace_profile_page
*pg
;
652 pg
= stat
->pages
= stat
->start
;
655 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
660 memset(stat
->hash
, 0,
661 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
664 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
666 struct ftrace_profile_page
*pg
;
671 /* If we already allocated, do nothing */
675 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
679 #ifdef CONFIG_DYNAMIC_FTRACE
680 functions
= ftrace_update_tot_cnt
;
683 * We do not know the number of functions that exist because
684 * dynamic tracing is what counts them. With past experience
685 * we have around 20K functions. That should be more than enough.
686 * It is highly unlikely we will execute every function in
692 pg
= stat
->start
= stat
->pages
;
694 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
696 for (i
= 1; i
< pages
; i
++) {
697 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
708 unsigned long tmp
= (unsigned long)pg
;
720 static int ftrace_profile_init_cpu(int cpu
)
722 struct ftrace_profile_stat
*stat
;
725 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
728 /* If the profile is already created, simply reset it */
729 ftrace_profile_reset(stat
);
734 * We are profiling all functions, but usually only a few thousand
735 * functions are hit. We'll make a hash of 1024 items.
737 size
= FTRACE_PROFILE_HASH_SIZE
;
739 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
744 /* Preallocate the function profiling pages */
745 if (ftrace_profile_pages_init(stat
) < 0) {
754 static int ftrace_profile_init(void)
759 for_each_online_cpu(cpu
) {
760 ret
= ftrace_profile_init_cpu(cpu
);
768 /* interrupts must be disabled */
769 static struct ftrace_profile
*
770 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
772 struct ftrace_profile
*rec
;
773 struct hlist_head
*hhd
;
776 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
777 hhd
= &stat
->hash
[key
];
779 if (hlist_empty(hhd
))
782 hlist_for_each_entry_rcu(rec
, hhd
, node
) {
790 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
791 struct ftrace_profile
*rec
)
795 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
796 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
800 * The memory is already allocated, this simply finds a new record to use.
802 static struct ftrace_profile
*
803 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
805 struct ftrace_profile
*rec
= NULL
;
807 /* prevent recursion (from NMIs) */
808 if (atomic_inc_return(&stat
->disabled
) != 1)
812 * Try to find the function again since an NMI
813 * could have added it
815 rec
= ftrace_find_profiled_func(stat
, ip
);
819 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
820 if (!stat
->pages
->next
)
822 stat
->pages
= stat
->pages
->next
;
825 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
827 ftrace_add_profile(stat
, rec
);
830 atomic_dec(&stat
->disabled
);
836 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
837 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
839 struct ftrace_profile_stat
*stat
;
840 struct ftrace_profile
*rec
;
843 if (!ftrace_profile_enabled
)
846 local_irq_save(flags
);
848 stat
= &__get_cpu_var(ftrace_profile_stats
);
849 if (!stat
->hash
|| !ftrace_profile_enabled
)
852 rec
= ftrace_find_profiled_func(stat
, ip
);
854 rec
= ftrace_profile_alloc(stat
, ip
);
861 local_irq_restore(flags
);
864 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
865 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
867 function_profile_call(trace
->func
, 0, NULL
, NULL
);
871 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
873 struct ftrace_profile_stat
*stat
;
874 unsigned long long calltime
;
875 struct ftrace_profile
*rec
;
878 local_irq_save(flags
);
879 stat
= &__get_cpu_var(ftrace_profile_stats
);
880 if (!stat
->hash
|| !ftrace_profile_enabled
)
883 /* If the calltime was zero'd ignore it */
884 if (!trace
->calltime
)
887 calltime
= trace
->rettime
- trace
->calltime
;
889 if (!(trace_flags
& TRACE_ITER_GRAPH_TIME
)) {
892 index
= trace
->depth
;
894 /* Append this call time to the parent time to subtract */
896 current
->ret_stack
[index
- 1].subtime
+= calltime
;
898 if (current
->ret_stack
[index
].subtime
< calltime
)
899 calltime
-= current
->ret_stack
[index
].subtime
;
904 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
906 rec
->time
+= calltime
;
907 rec
->time_squared
+= calltime
* calltime
;
911 local_irq_restore(flags
);
914 static int register_ftrace_profiler(void)
916 return register_ftrace_graph(&profile_graph_return
,
917 &profile_graph_entry
);
920 static void unregister_ftrace_profiler(void)
922 unregister_ftrace_graph();
925 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
926 .func
= function_profile_call
,
927 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
928 INIT_REGEX_LOCK(ftrace_profile_ops
)
931 static int register_ftrace_profiler(void)
933 return register_ftrace_function(&ftrace_profile_ops
);
936 static void unregister_ftrace_profiler(void)
938 unregister_ftrace_function(&ftrace_profile_ops
);
940 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
943 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
944 size_t cnt
, loff_t
*ppos
)
949 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
955 mutex_lock(&ftrace_profile_lock
);
956 if (ftrace_profile_enabled
^ val
) {
958 ret
= ftrace_profile_init();
964 ret
= register_ftrace_profiler();
969 ftrace_profile_enabled
= 1;
971 ftrace_profile_enabled
= 0;
973 * unregister_ftrace_profiler calls stop_machine
974 * so this acts like an synchronize_sched.
976 unregister_ftrace_profiler();
980 mutex_unlock(&ftrace_profile_lock
);
988 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
989 size_t cnt
, loff_t
*ppos
)
991 char buf
[64]; /* big enough to hold a number */
994 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
995 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
998 static const struct file_operations ftrace_profile_fops
= {
999 .open
= tracing_open_generic
,
1000 .read
= ftrace_profile_read
,
1001 .write
= ftrace_profile_write
,
1002 .llseek
= default_llseek
,
1005 /* used to initialize the real stat files */
1006 static struct tracer_stat function_stats __initdata
= {
1007 .name
= "functions",
1008 .stat_start
= function_stat_start
,
1009 .stat_next
= function_stat_next
,
1010 .stat_cmp
= function_stat_cmp
,
1011 .stat_headers
= function_stat_headers
,
1012 .stat_show
= function_stat_show
1015 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1017 struct ftrace_profile_stat
*stat
;
1018 struct dentry
*entry
;
1023 for_each_possible_cpu(cpu
) {
1024 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1026 /* allocate enough for function name + cpu number */
1027 name
= kmalloc(32, GFP_KERNEL
);
1030 * The files created are permanent, if something happens
1031 * we still do not free memory.
1034 "Could not allocate stat file for cpu %d\n",
1038 stat
->stat
= function_stats
;
1039 snprintf(name
, 32, "function%d", cpu
);
1040 stat
->stat
.name
= name
;
1041 ret
= register_stat_tracer(&stat
->stat
);
1044 "Could not register function stat for cpu %d\n",
1051 entry
= debugfs_create_file("function_profile_enabled", 0644,
1052 d_tracer
, NULL
, &ftrace_profile_fops
);
1054 pr_warning("Could not create debugfs "
1055 "'function_profile_enabled' entry\n");
1058 #else /* CONFIG_FUNCTION_PROFILER */
1059 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1062 #endif /* CONFIG_FUNCTION_PROFILER */
1064 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1067 ftrace_filter_lseek(struct file
*file
, loff_t offset
, int whence
)
1071 if (file
->f_mode
& FMODE_READ
)
1072 ret
= seq_lseek(file
, offset
, whence
);
1074 file
->f_pos
= ret
= 1;
1079 #ifdef CONFIG_DYNAMIC_FTRACE
1081 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1082 # error Dynamic ftrace depends on MCOUNT_RECORD
1085 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1087 struct ftrace_func_probe
{
1088 struct hlist_node node
;
1089 struct ftrace_probe_ops
*ops
;
1090 unsigned long flags
;
1093 struct list_head free_list
;
1096 struct ftrace_func_entry
{
1097 struct hlist_node hlist
;
1101 struct ftrace_hash
{
1102 unsigned long size_bits
;
1103 struct hlist_head
*buckets
;
1104 unsigned long count
;
1105 struct rcu_head rcu
;
1109 * We make these constant because no one should touch them,
1110 * but they are used as the default "empty hash", to avoid allocating
1111 * it all the time. These are in a read only section such that if
1112 * anyone does try to modify it, it will cause an exception.
1114 static const struct hlist_head empty_buckets
[1];
1115 static const struct ftrace_hash empty_hash
= {
1116 .buckets
= (struct hlist_head
*)empty_buckets
,
1118 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1120 static struct ftrace_ops global_ops
= {
1121 .func
= ftrace_stub
,
1122 .notrace_hash
= EMPTY_HASH
,
1123 .filter_hash
= EMPTY_HASH
,
1124 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
1125 INIT_REGEX_LOCK(global_ops
)
1128 struct ftrace_page
{
1129 struct ftrace_page
*next
;
1130 struct dyn_ftrace
*records
;
1135 static struct ftrace_page
*ftrace_new_pgs
;
1137 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1138 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1140 /* estimate from running different kernels */
1141 #define NR_TO_INIT 10000
1143 static struct ftrace_page
*ftrace_pages_start
;
1144 static struct ftrace_page
*ftrace_pages
;
1146 static bool ftrace_hash_empty(struct ftrace_hash
*hash
)
1148 return !hash
|| !hash
->count
;
1151 static struct ftrace_func_entry
*
1152 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1155 struct ftrace_func_entry
*entry
;
1156 struct hlist_head
*hhd
;
1158 if (ftrace_hash_empty(hash
))
1161 if (hash
->size_bits
> 0)
1162 key
= hash_long(ip
, hash
->size_bits
);
1166 hhd
= &hash
->buckets
[key
];
1168 hlist_for_each_entry_rcu(entry
, hhd
, hlist
) {
1169 if (entry
->ip
== ip
)
1175 static void __add_hash_entry(struct ftrace_hash
*hash
,
1176 struct ftrace_func_entry
*entry
)
1178 struct hlist_head
*hhd
;
1181 if (hash
->size_bits
)
1182 key
= hash_long(entry
->ip
, hash
->size_bits
);
1186 hhd
= &hash
->buckets
[key
];
1187 hlist_add_head(&entry
->hlist
, hhd
);
1191 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1193 struct ftrace_func_entry
*entry
;
1195 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1200 __add_hash_entry(hash
, entry
);
1206 free_hash_entry(struct ftrace_hash
*hash
,
1207 struct ftrace_func_entry
*entry
)
1209 hlist_del(&entry
->hlist
);
1215 remove_hash_entry(struct ftrace_hash
*hash
,
1216 struct ftrace_func_entry
*entry
)
1218 hlist_del(&entry
->hlist
);
1222 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1224 struct hlist_head
*hhd
;
1225 struct hlist_node
*tn
;
1226 struct ftrace_func_entry
*entry
;
1227 int size
= 1 << hash
->size_bits
;
1233 for (i
= 0; i
< size
; i
++) {
1234 hhd
= &hash
->buckets
[i
];
1235 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1236 free_hash_entry(hash
, entry
);
1238 FTRACE_WARN_ON(hash
->count
);
1241 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1243 if (!hash
|| hash
== EMPTY_HASH
)
1245 ftrace_hash_clear(hash
);
1246 kfree(hash
->buckets
);
1250 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1252 struct ftrace_hash
*hash
;
1254 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1255 free_ftrace_hash(hash
);
1258 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1260 if (!hash
|| hash
== EMPTY_HASH
)
1262 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1265 void ftrace_free_filter(struct ftrace_ops
*ops
)
1267 ftrace_ops_init(ops
);
1268 free_ftrace_hash(ops
->filter_hash
);
1269 free_ftrace_hash(ops
->notrace_hash
);
1272 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1274 struct ftrace_hash
*hash
;
1277 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1281 size
= 1 << size_bits
;
1282 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1284 if (!hash
->buckets
) {
1289 hash
->size_bits
= size_bits
;
1294 static struct ftrace_hash
*
1295 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1297 struct ftrace_func_entry
*entry
;
1298 struct ftrace_hash
*new_hash
;
1303 new_hash
= alloc_ftrace_hash(size_bits
);
1308 if (ftrace_hash_empty(hash
))
1311 size
= 1 << hash
->size_bits
;
1312 for (i
= 0; i
< size
; i
++) {
1313 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1314 ret
= add_hash_entry(new_hash
, entry
->ip
);
1320 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1325 free_ftrace_hash(new_hash
);
1330 ftrace_hash_rec_disable(struct ftrace_ops
*ops
, int filter_hash
);
1332 ftrace_hash_rec_enable(struct ftrace_ops
*ops
, int filter_hash
);
1335 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1336 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1338 struct ftrace_func_entry
*entry
;
1339 struct hlist_node
*tn
;
1340 struct hlist_head
*hhd
;
1341 struct ftrace_hash
*old_hash
;
1342 struct ftrace_hash
*new_hash
;
1343 int size
= src
->count
;
1349 * Remove the current set, update the hash and add
1352 ftrace_hash_rec_disable(ops
, enable
);
1355 * If the new source is empty, just free dst and assign it
1359 free_ftrace_hash_rcu(*dst
);
1360 rcu_assign_pointer(*dst
, EMPTY_HASH
);
1361 /* still need to update the function records */
1367 * Make the hash size about 1/2 the # found
1369 for (size
/= 2; size
; size
>>= 1)
1372 /* Don't allocate too much */
1373 if (bits
> FTRACE_HASH_MAX_BITS
)
1374 bits
= FTRACE_HASH_MAX_BITS
;
1377 new_hash
= alloc_ftrace_hash(bits
);
1381 size
= 1 << src
->size_bits
;
1382 for (i
= 0; i
< size
; i
++) {
1383 hhd
= &src
->buckets
[i
];
1384 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1385 remove_hash_entry(src
, entry
);
1386 __add_hash_entry(new_hash
, entry
);
1391 rcu_assign_pointer(*dst
, new_hash
);
1392 free_ftrace_hash_rcu(old_hash
);
1397 * Enable regardless of ret:
1398 * On success, we enable the new hash.
1399 * On failure, we re-enable the original hash.
1401 ftrace_hash_rec_enable(ops
, enable
);
1407 * Test the hashes for this ops to see if we want to call
1408 * the ops->func or not.
1410 * It's a match if the ip is in the ops->filter_hash or
1411 * the filter_hash does not exist or is empty,
1413 * the ip is not in the ops->notrace_hash.
1415 * This needs to be called with preemption disabled as
1416 * the hashes are freed with call_rcu_sched().
1419 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
)
1421 struct ftrace_hash
*filter_hash
;
1422 struct ftrace_hash
*notrace_hash
;
1425 filter_hash
= rcu_dereference_raw(ops
->filter_hash
);
1426 notrace_hash
= rcu_dereference_raw(ops
->notrace_hash
);
1428 if ((ftrace_hash_empty(filter_hash
) ||
1429 ftrace_lookup_ip(filter_hash
, ip
)) &&
1430 (ftrace_hash_empty(notrace_hash
) ||
1431 !ftrace_lookup_ip(notrace_hash
, ip
)))
1440 * This is a double for. Do not use 'break' to break out of the loop,
1441 * you must use a goto.
1443 #define do_for_each_ftrace_rec(pg, rec) \
1444 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1446 for (_____i = 0; _____i < pg->index; _____i++) { \
1447 rec = &pg->records[_____i];
1449 #define while_for_each_ftrace_rec() \
1454 static int ftrace_cmp_recs(const void *a
, const void *b
)
1456 const struct dyn_ftrace
*key
= a
;
1457 const struct dyn_ftrace
*rec
= b
;
1459 if (key
->flags
< rec
->ip
)
1461 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1466 static unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1468 struct ftrace_page
*pg
;
1469 struct dyn_ftrace
*rec
;
1470 struct dyn_ftrace key
;
1473 key
.flags
= end
; /* overload flags, as it is unsigned long */
1475 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1476 if (end
< pg
->records
[0].ip
||
1477 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1479 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1480 sizeof(struct dyn_ftrace
),
1490 * ftrace_location - return true if the ip giving is a traced location
1491 * @ip: the instruction pointer to check
1493 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1494 * That is, the instruction that is either a NOP or call to
1495 * the function tracer. It checks the ftrace internal tables to
1496 * determine if the address belongs or not.
1498 unsigned long ftrace_location(unsigned long ip
)
1500 return ftrace_location_range(ip
, ip
);
1504 * ftrace_text_reserved - return true if range contains an ftrace location
1505 * @start: start of range to search
1506 * @end: end of range to search (inclusive). @end points to the last byte to check.
1508 * Returns 1 if @start and @end contains a ftrace location.
1509 * That is, the instruction that is either a NOP or call to
1510 * the function tracer. It checks the ftrace internal tables to
1511 * determine if the address belongs or not.
1513 int ftrace_text_reserved(void *start
, void *end
)
1517 ret
= ftrace_location_range((unsigned long)start
,
1518 (unsigned long)end
);
1523 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1527 struct ftrace_hash
*hash
;
1528 struct ftrace_hash
*other_hash
;
1529 struct ftrace_page
*pg
;
1530 struct dyn_ftrace
*rec
;
1534 /* Only update if the ops has been registered */
1535 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1539 * In the filter_hash case:
1540 * If the count is zero, we update all records.
1541 * Otherwise we just update the items in the hash.
1543 * In the notrace_hash case:
1544 * We enable the update in the hash.
1545 * As disabling notrace means enabling the tracing,
1546 * and enabling notrace means disabling, the inc variable
1550 hash
= ops
->filter_hash
;
1551 other_hash
= ops
->notrace_hash
;
1552 if (ftrace_hash_empty(hash
))
1556 hash
= ops
->notrace_hash
;
1557 other_hash
= ops
->filter_hash
;
1559 * If the notrace hash has no items,
1560 * then there's nothing to do.
1562 if (ftrace_hash_empty(hash
))
1566 do_for_each_ftrace_rec(pg
, rec
) {
1567 int in_other_hash
= 0;
1573 * Only the filter_hash affects all records.
1574 * Update if the record is not in the notrace hash.
1576 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1579 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1580 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1585 if (filter_hash
&& in_hash
&& !in_other_hash
)
1587 else if (!filter_hash
&& in_hash
&&
1588 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1596 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == FTRACE_REF_MAX
))
1599 * If any ops wants regs saved for this function
1600 * then all ops will get saved regs.
1602 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1603 rec
->flags
|= FTRACE_FL_REGS
;
1605 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == 0))
1610 /* Shortcut, if we handled all records, we are done. */
1611 if (!all
&& count
== hash
->count
)
1613 } while_for_each_ftrace_rec();
1616 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1619 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1622 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1625 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1628 static void print_ip_ins(const char *fmt
, unsigned char *p
)
1632 printk(KERN_CONT
"%s", fmt
);
1634 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1635 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1639 * ftrace_bug - report and shutdown function tracer
1640 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1641 * @ip: The address that failed
1643 * The arch code that enables or disables the function tracing
1644 * can call ftrace_bug() when it has detected a problem in
1645 * modifying the code. @failed should be one of either:
1646 * EFAULT - if the problem happens on reading the @ip address
1647 * EINVAL - if what is read at @ip is not what was expected
1648 * EPERM - if the problem happens on writting to the @ip address
1650 void ftrace_bug(int failed
, unsigned long ip
)
1654 FTRACE_WARN_ON_ONCE(1);
1655 pr_info("ftrace faulted on modifying ");
1659 FTRACE_WARN_ON_ONCE(1);
1660 pr_info("ftrace failed to modify ");
1662 print_ip_ins(" actual: ", (unsigned char *)ip
);
1663 printk(KERN_CONT
"\n");
1666 FTRACE_WARN_ON_ONCE(1);
1667 pr_info("ftrace faulted on writing ");
1671 FTRACE_WARN_ON_ONCE(1);
1672 pr_info("ftrace faulted on unknown error ");
1677 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
1679 unsigned long flag
= 0UL;
1682 * If we are updating calls:
1684 * If the record has a ref count, then we need to enable it
1685 * because someone is using it.
1687 * Otherwise we make sure its disabled.
1689 * If we are disabling calls, then disable all records that
1692 if (enable
&& (rec
->flags
& ~FTRACE_FL_MASK
))
1693 flag
= FTRACE_FL_ENABLED
;
1696 * If enabling and the REGS flag does not match the REGS_EN, then
1697 * do not ignore this record. Set flags to fail the compare against
1701 (!(rec
->flags
& FTRACE_FL_REGS
) != !(rec
->flags
& FTRACE_FL_REGS_EN
)))
1702 flag
|= FTRACE_FL_REGS
;
1704 /* If the state of this record hasn't changed, then do nothing */
1705 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
1706 return FTRACE_UPDATE_IGNORE
;
1709 /* Save off if rec is being enabled (for return value) */
1710 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
1713 rec
->flags
|= FTRACE_FL_ENABLED
;
1714 if (flag
& FTRACE_FL_REGS
) {
1715 if (rec
->flags
& FTRACE_FL_REGS
)
1716 rec
->flags
|= FTRACE_FL_REGS_EN
;
1718 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
1723 * If this record is being updated from a nop, then
1724 * return UPDATE_MAKE_CALL.
1725 * Otherwise, if the EN flag is set, then return
1726 * UPDATE_MODIFY_CALL_REGS to tell the caller to convert
1727 * from the non-save regs, to a save regs function.
1729 * return UPDATE_MODIFY_CALL to tell the caller to convert
1730 * from the save regs, to a non-save regs function.
1732 if (flag
& FTRACE_FL_ENABLED
)
1733 return FTRACE_UPDATE_MAKE_CALL
;
1734 else if (rec
->flags
& FTRACE_FL_REGS_EN
)
1735 return FTRACE_UPDATE_MODIFY_CALL_REGS
;
1737 return FTRACE_UPDATE_MODIFY_CALL
;
1741 /* If there's no more users, clear all flags */
1742 if (!(rec
->flags
& ~FTRACE_FL_MASK
))
1745 /* Just disable the record (keep REGS state) */
1746 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1749 return FTRACE_UPDATE_MAKE_NOP
;
1753 * ftrace_update_record, set a record that now is tracing or not
1754 * @rec: the record to update
1755 * @enable: set to 1 if the record is tracing, zero to force disable
1757 * The records that represent all functions that can be traced need
1758 * to be updated when tracing has been enabled.
1760 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
1762 return ftrace_check_record(rec
, enable
, 1);
1766 * ftrace_test_record, check if the record has been enabled or not
1767 * @rec: the record to test
1768 * @enable: set to 1 to check if enabled, 0 if it is disabled
1770 * The arch code may need to test if a record is already set to
1771 * tracing to determine how to modify the function code that it
1774 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
1776 return ftrace_check_record(rec
, enable
, 0);
1780 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
1782 unsigned long ftrace_old_addr
;
1783 unsigned long ftrace_addr
;
1786 ret
= ftrace_update_record(rec
, enable
);
1788 if (rec
->flags
& FTRACE_FL_REGS
)
1789 ftrace_addr
= (unsigned long)FTRACE_REGS_ADDR
;
1791 ftrace_addr
= (unsigned long)FTRACE_ADDR
;
1794 case FTRACE_UPDATE_IGNORE
:
1797 case FTRACE_UPDATE_MAKE_CALL
:
1798 return ftrace_make_call(rec
, ftrace_addr
);
1800 case FTRACE_UPDATE_MAKE_NOP
:
1801 return ftrace_make_nop(NULL
, rec
, ftrace_addr
);
1803 case FTRACE_UPDATE_MODIFY_CALL_REGS
:
1804 case FTRACE_UPDATE_MODIFY_CALL
:
1805 if (rec
->flags
& FTRACE_FL_REGS
)
1806 ftrace_old_addr
= (unsigned long)FTRACE_ADDR
;
1808 ftrace_old_addr
= (unsigned long)FTRACE_REGS_ADDR
;
1810 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
1813 return -1; /* unknow ftrace bug */
1816 void __weak
ftrace_replace_code(int enable
)
1818 struct dyn_ftrace
*rec
;
1819 struct ftrace_page
*pg
;
1822 if (unlikely(ftrace_disabled
))
1825 do_for_each_ftrace_rec(pg
, rec
) {
1826 failed
= __ftrace_replace_code(rec
, enable
);
1828 ftrace_bug(failed
, rec
->ip
);
1829 /* Stop processing */
1832 } while_for_each_ftrace_rec();
1835 struct ftrace_rec_iter
{
1836 struct ftrace_page
*pg
;
1841 * ftrace_rec_iter_start, start up iterating over traced functions
1843 * Returns an iterator handle that is used to iterate over all
1844 * the records that represent address locations where functions
1847 * May return NULL if no records are available.
1849 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
1852 * We only use a single iterator.
1853 * Protected by the ftrace_lock mutex.
1855 static struct ftrace_rec_iter ftrace_rec_iter
;
1856 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
1858 iter
->pg
= ftrace_pages_start
;
1861 /* Could have empty pages */
1862 while (iter
->pg
&& !iter
->pg
->index
)
1863 iter
->pg
= iter
->pg
->next
;
1872 * ftrace_rec_iter_next, get the next record to process.
1873 * @iter: The handle to the iterator.
1875 * Returns the next iterator after the given iterator @iter.
1877 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
1881 if (iter
->index
>= iter
->pg
->index
) {
1882 iter
->pg
= iter
->pg
->next
;
1885 /* Could have empty pages */
1886 while (iter
->pg
&& !iter
->pg
->index
)
1887 iter
->pg
= iter
->pg
->next
;
1897 * ftrace_rec_iter_record, get the record at the iterator location
1898 * @iter: The current iterator location
1900 * Returns the record that the current @iter is at.
1902 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
1904 return &iter
->pg
->records
[iter
->index
];
1908 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
1915 if (unlikely(ftrace_disabled
))
1918 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
1920 ftrace_bug(ret
, ip
);
1927 * archs can override this function if they must do something
1928 * before the modifying code is performed.
1930 int __weak
ftrace_arch_code_modify_prepare(void)
1936 * archs can override this function if they must do something
1937 * after the modifying code is performed.
1939 int __weak
ftrace_arch_code_modify_post_process(void)
1944 void ftrace_modify_all_code(int command
)
1946 if (command
& FTRACE_UPDATE_CALLS
)
1947 ftrace_replace_code(1);
1948 else if (command
& FTRACE_DISABLE_CALLS
)
1949 ftrace_replace_code(0);
1951 if (command
& FTRACE_UPDATE_TRACE_FUNC
)
1952 ftrace_update_ftrace_func(ftrace_trace_function
);
1954 if (command
& FTRACE_START_FUNC_RET
)
1955 ftrace_enable_ftrace_graph_caller();
1956 else if (command
& FTRACE_STOP_FUNC_RET
)
1957 ftrace_disable_ftrace_graph_caller();
1960 static int __ftrace_modify_code(void *data
)
1962 int *command
= data
;
1964 ftrace_modify_all_code(*command
);
1970 * ftrace_run_stop_machine, go back to the stop machine method
1971 * @command: The command to tell ftrace what to do
1973 * If an arch needs to fall back to the stop machine method, the
1974 * it can call this function.
1976 void ftrace_run_stop_machine(int command
)
1978 stop_machine(__ftrace_modify_code
, &command
, NULL
);
1982 * arch_ftrace_update_code, modify the code to trace or not trace
1983 * @command: The command that needs to be done
1985 * Archs can override this function if it does not need to
1986 * run stop_machine() to modify code.
1988 void __weak
arch_ftrace_update_code(int command
)
1990 ftrace_run_stop_machine(command
);
1993 static void ftrace_run_update_code(int command
)
1997 ret
= ftrace_arch_code_modify_prepare();
1998 FTRACE_WARN_ON(ret
);
2002 * Do not call function tracer while we update the code.
2003 * We are in stop machine.
2005 function_trace_stop
++;
2008 * By default we use stop_machine() to modify the code.
2009 * But archs can do what ever they want as long as it
2010 * is safe. The stop_machine() is the safest, but also
2011 * produces the most overhead.
2013 arch_ftrace_update_code(command
);
2015 function_trace_stop
--;
2017 ret
= ftrace_arch_code_modify_post_process();
2018 FTRACE_WARN_ON(ret
);
2021 static ftrace_func_t saved_ftrace_func
;
2022 static int ftrace_start_up
;
2023 static int global_start_up
;
2025 static void ftrace_startup_enable(int command
)
2027 if (saved_ftrace_func
!= ftrace_trace_function
) {
2028 saved_ftrace_func
= ftrace_trace_function
;
2029 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2032 if (!command
|| !ftrace_enabled
)
2035 ftrace_run_update_code(command
);
2038 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2040 bool hash_enable
= true;
2042 if (unlikely(ftrace_disabled
))
2046 command
|= FTRACE_UPDATE_CALLS
;
2048 /* ops marked global share the filter hashes */
2049 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
2051 /* Don't update hash if global is already set */
2052 if (global_start_up
)
2053 hash_enable
= false;
2057 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
2059 ftrace_hash_rec_enable(ops
, 1);
2061 ftrace_startup_enable(command
);
2066 static void ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2068 bool hash_disable
= true;
2070 if (unlikely(ftrace_disabled
))
2075 * Just warn in case of unbalance, no need to kill ftrace, it's not
2076 * critical but the ftrace_call callers may be never nopped again after
2077 * further ftrace uses.
2079 WARN_ON_ONCE(ftrace_start_up
< 0);
2081 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
2084 WARN_ON_ONCE(global_start_up
< 0);
2085 /* Don't update hash if global still has users */
2086 if (global_start_up
) {
2087 WARN_ON_ONCE(!ftrace_start_up
);
2088 hash_disable
= false;
2093 ftrace_hash_rec_disable(ops
, 1);
2095 if (ops
!= &global_ops
|| !global_start_up
)
2096 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2098 command
|= FTRACE_UPDATE_CALLS
;
2100 if (saved_ftrace_func
!= ftrace_trace_function
) {
2101 saved_ftrace_func
= ftrace_trace_function
;
2102 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2105 if (!command
|| !ftrace_enabled
)
2108 ftrace_run_update_code(command
);
2111 static void ftrace_startup_sysctl(void)
2113 if (unlikely(ftrace_disabled
))
2116 /* Force update next time */
2117 saved_ftrace_func
= NULL
;
2118 /* ftrace_start_up is true if we want ftrace running */
2119 if (ftrace_start_up
)
2120 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
2123 static void ftrace_shutdown_sysctl(void)
2125 if (unlikely(ftrace_disabled
))
2128 /* ftrace_start_up is true if ftrace is running */
2129 if (ftrace_start_up
)
2130 ftrace_run_update_code(FTRACE_DISABLE_CALLS
);
2133 static cycle_t ftrace_update_time
;
2134 static unsigned long ftrace_update_cnt
;
2135 unsigned long ftrace_update_tot_cnt
;
2137 static int ops_traces_mod(struct ftrace_ops
*ops
)
2139 struct ftrace_hash
*hash
;
2141 hash
= ops
->filter_hash
;
2142 return ftrace_hash_empty(hash
);
2145 static int ftrace_update_code(struct module
*mod
)
2147 struct ftrace_page
*pg
;
2148 struct dyn_ftrace
*p
;
2149 cycle_t start
, stop
;
2150 unsigned long ref
= 0;
2154 * When adding a module, we need to check if tracers are
2155 * currently enabled and if they are set to trace all functions.
2156 * If they are, we need to enable the module functions as well
2157 * as update the reference counts for those function records.
2160 struct ftrace_ops
*ops
;
2162 for (ops
= ftrace_ops_list
;
2163 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2164 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
&&
2165 ops_traces_mod(ops
))
2170 start
= ftrace_now(raw_smp_processor_id());
2171 ftrace_update_cnt
= 0;
2173 for (pg
= ftrace_new_pgs
; pg
; pg
= pg
->next
) {
2175 for (i
= 0; i
< pg
->index
; i
++) {
2176 /* If something went wrong, bail without enabling anything */
2177 if (unlikely(ftrace_disabled
))
2180 p
= &pg
->records
[i
];
2184 * Do the initial record conversion from mcount jump
2185 * to the NOP instructions.
2187 if (!ftrace_code_disable(mod
, p
))
2190 ftrace_update_cnt
++;
2193 * If the tracing is enabled, go ahead and enable the record.
2195 * The reason not to enable the record immediatelly is the
2196 * inherent check of ftrace_make_nop/ftrace_make_call for
2197 * correct previous instructions. Making first the NOP
2198 * conversion puts the module to the correct state, thus
2199 * passing the ftrace_make_call check.
2201 if (ftrace_start_up
&& ref
) {
2202 int failed
= __ftrace_replace_code(p
, 1);
2204 ftrace_bug(failed
, p
->ip
);
2209 ftrace_new_pgs
= NULL
;
2211 stop
= ftrace_now(raw_smp_processor_id());
2212 ftrace_update_time
= stop
- start
;
2213 ftrace_update_tot_cnt
+= ftrace_update_cnt
;
2218 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2223 if (WARN_ON(!count
))
2226 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2229 * We want to fill as much as possible. No more than a page
2232 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2236 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2239 /* if we can't allocate this size, try something smaller */
2246 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2255 static struct ftrace_page
*
2256 ftrace_allocate_pages(unsigned long num_to_init
)
2258 struct ftrace_page
*start_pg
;
2259 struct ftrace_page
*pg
;
2266 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2271 * Try to allocate as much as possible in one continues
2272 * location that fills in all of the space. We want to
2273 * waste as little space as possible.
2276 cnt
= ftrace_allocate_records(pg
, num_to_init
);
2284 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2295 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
2296 free_pages((unsigned long)pg
->records
, order
);
2297 start_pg
= pg
->next
;
2301 pr_info("ftrace: FAILED to allocate memory for functions\n");
2305 static int __init
ftrace_dyn_table_alloc(unsigned long num_to_init
)
2310 pr_info("ftrace: No functions to be traced?\n");
2314 cnt
= num_to_init
/ ENTRIES_PER_PAGE
;
2315 pr_info("ftrace: allocating %ld entries in %d pages\n",
2316 num_to_init
, cnt
+ 1);
2321 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2323 struct ftrace_iterator
{
2326 struct ftrace_page
*pg
;
2327 struct dyn_ftrace
*func
;
2328 struct ftrace_func_probe
*probe
;
2329 struct trace_parser parser
;
2330 struct ftrace_hash
*hash
;
2331 struct ftrace_ops
*ops
;
2338 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
2340 struct ftrace_iterator
*iter
= m
->private;
2341 struct hlist_node
*hnd
= NULL
;
2342 struct hlist_head
*hhd
;
2348 hnd
= &iter
->probe
->node
;
2350 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
2353 hhd
= &ftrace_func_hash
[iter
->hidx
];
2355 if (hlist_empty(hhd
)) {
2371 if (WARN_ON_ONCE(!hnd
))
2374 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
2379 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
2381 struct ftrace_iterator
*iter
= m
->private;
2385 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
2388 if (iter
->func_pos
> *pos
)
2392 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
2393 p
= t_hash_next(m
, &l
);
2400 /* Only set this if we have an item */
2401 iter
->flags
|= FTRACE_ITER_HASH
;
2407 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
2409 struct ftrace_func_probe
*rec
;
2412 if (WARN_ON_ONCE(!rec
))
2415 if (rec
->ops
->print
)
2416 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
2418 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
2421 seq_printf(m
, ":%p", rec
->data
);
2428 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2430 struct ftrace_iterator
*iter
= m
->private;
2431 struct ftrace_ops
*ops
= iter
->ops
;
2432 struct dyn_ftrace
*rec
= NULL
;
2434 if (unlikely(ftrace_disabled
))
2437 if (iter
->flags
& FTRACE_ITER_HASH
)
2438 return t_hash_next(m
, pos
);
2441 iter
->pos
= iter
->func_pos
= *pos
;
2443 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
2444 return t_hash_start(m
, pos
);
2447 if (iter
->idx
>= iter
->pg
->index
) {
2448 if (iter
->pg
->next
) {
2449 iter
->pg
= iter
->pg
->next
;
2454 rec
= &iter
->pg
->records
[iter
->idx
++];
2455 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
2456 !(ftrace_lookup_ip(ops
->filter_hash
, rec
->ip
))) ||
2458 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
2459 !ftrace_lookup_ip(ops
->notrace_hash
, rec
->ip
)) ||
2461 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
2462 !(rec
->flags
& ~FTRACE_FL_MASK
))) {
2470 return t_hash_start(m
, pos
);
2477 static void reset_iter_read(struct ftrace_iterator
*iter
)
2481 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
2484 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2486 struct ftrace_iterator
*iter
= m
->private;
2487 struct ftrace_ops
*ops
= iter
->ops
;
2491 mutex_lock(&ftrace_lock
);
2493 if (unlikely(ftrace_disabled
))
2497 * If an lseek was done, then reset and start from beginning.
2499 if (*pos
< iter
->pos
)
2500 reset_iter_read(iter
);
2503 * For set_ftrace_filter reading, if we have the filter
2504 * off, we can short cut and just print out that all
2505 * functions are enabled.
2507 if (iter
->flags
& FTRACE_ITER_FILTER
&&
2508 ftrace_hash_empty(ops
->filter_hash
)) {
2510 return t_hash_start(m
, pos
);
2511 iter
->flags
|= FTRACE_ITER_PRINTALL
;
2512 /* reset in case of seek/pread */
2513 iter
->flags
&= ~FTRACE_ITER_HASH
;
2517 if (iter
->flags
& FTRACE_ITER_HASH
)
2518 return t_hash_start(m
, pos
);
2521 * Unfortunately, we need to restart at ftrace_pages_start
2522 * every time we let go of the ftrace_mutex. This is because
2523 * those pointers can change without the lock.
2525 iter
->pg
= ftrace_pages_start
;
2527 for (l
= 0; l
<= *pos
; ) {
2528 p
= t_next(m
, p
, &l
);
2534 return t_hash_start(m
, pos
);
2539 static void t_stop(struct seq_file
*m
, void *p
)
2541 mutex_unlock(&ftrace_lock
);
2544 static int t_show(struct seq_file
*m
, void *v
)
2546 struct ftrace_iterator
*iter
= m
->private;
2547 struct dyn_ftrace
*rec
;
2549 if (iter
->flags
& FTRACE_ITER_HASH
)
2550 return t_hash_show(m
, iter
);
2552 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
2553 seq_printf(m
, "#### all functions enabled ####\n");
2562 seq_printf(m
, "%ps", (void *)rec
->ip
);
2563 if (iter
->flags
& FTRACE_ITER_ENABLED
)
2564 seq_printf(m
, " (%ld)%s",
2565 rec
->flags
& ~FTRACE_FL_MASK
,
2566 rec
->flags
& FTRACE_FL_REGS
? " R" : "");
2567 seq_printf(m
, "\n");
2572 static const struct seq_operations show_ftrace_seq_ops
= {
2580 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
2582 struct ftrace_iterator
*iter
;
2584 if (unlikely(ftrace_disabled
))
2587 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2589 iter
->pg
= ftrace_pages_start
;
2590 iter
->ops
= &global_ops
;
2593 return iter
? 0 : -ENOMEM
;
2597 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
2599 struct ftrace_iterator
*iter
;
2601 if (unlikely(ftrace_disabled
))
2604 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2606 iter
->pg
= ftrace_pages_start
;
2607 iter
->flags
= FTRACE_ITER_ENABLED
;
2608 iter
->ops
= &global_ops
;
2611 return iter
? 0 : -ENOMEM
;
2614 static void ftrace_filter_reset(struct ftrace_hash
*hash
)
2616 mutex_lock(&ftrace_lock
);
2617 ftrace_hash_clear(hash
);
2618 mutex_unlock(&ftrace_lock
);
2622 * ftrace_regex_open - initialize function tracer filter files
2623 * @ops: The ftrace_ops that hold the hash filters
2624 * @flag: The type of filter to process
2625 * @inode: The inode, usually passed in to your open routine
2626 * @file: The file, usually passed in to your open routine
2628 * ftrace_regex_open() initializes the filter files for the
2629 * @ops. Depending on @flag it may process the filter hash or
2630 * the notrace hash of @ops. With this called from the open
2631 * routine, you can use ftrace_filter_write() for the write
2632 * routine if @flag has FTRACE_ITER_FILTER set, or
2633 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2634 * ftrace_filter_lseek() should be used as the lseek routine, and
2635 * release must call ftrace_regex_release().
2638 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
2639 struct inode
*inode
, struct file
*file
)
2641 struct ftrace_iterator
*iter
;
2642 struct ftrace_hash
*hash
;
2645 ftrace_ops_init(ops
);
2647 if (unlikely(ftrace_disabled
))
2650 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2654 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
2662 mutex_lock(&ops
->regex_lock
);
2664 if (flag
& FTRACE_ITER_NOTRACE
)
2665 hash
= ops
->notrace_hash
;
2667 hash
= ops
->filter_hash
;
2669 if (file
->f_mode
& FMODE_WRITE
) {
2670 iter
->hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, hash
);
2672 trace_parser_put(&iter
->parser
);
2679 if ((file
->f_mode
& FMODE_WRITE
) &&
2680 (file
->f_flags
& O_TRUNC
))
2681 ftrace_filter_reset(iter
->hash
);
2683 if (file
->f_mode
& FMODE_READ
) {
2684 iter
->pg
= ftrace_pages_start
;
2686 ret
= seq_open(file
, &show_ftrace_seq_ops
);
2688 struct seq_file
*m
= file
->private_data
;
2692 free_ftrace_hash(iter
->hash
);
2693 trace_parser_put(&iter
->parser
);
2697 file
->private_data
= iter
;
2700 mutex_unlock(&ops
->regex_lock
);
2706 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
2708 return ftrace_regex_open(&global_ops
,
2709 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
2714 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
2716 return ftrace_regex_open(&global_ops
, FTRACE_ITER_NOTRACE
,
2720 static int ftrace_match(char *str
, char *regex
, int len
, int type
)
2727 if (strcmp(str
, regex
) == 0)
2730 case MATCH_FRONT_ONLY
:
2731 if (strncmp(str
, regex
, len
) == 0)
2734 case MATCH_MIDDLE_ONLY
:
2735 if (strstr(str
, regex
))
2738 case MATCH_END_ONLY
:
2740 if (slen
>= len
&& memcmp(str
+ slen
- len
, regex
, len
) == 0)
2749 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int not)
2751 struct ftrace_func_entry
*entry
;
2754 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
2756 /* Do nothing if it doesn't exist */
2760 free_hash_entry(hash
, entry
);
2762 /* Do nothing if it exists */
2766 ret
= add_hash_entry(hash
, rec
->ip
);
2772 ftrace_match_record(struct dyn_ftrace
*rec
, char *mod
,
2773 char *regex
, int len
, int type
)
2775 char str
[KSYM_SYMBOL_LEN
];
2778 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
2781 /* module lookup requires matching the module */
2782 if (!modname
|| strcmp(modname
, mod
))
2785 /* blank search means to match all funcs in the mod */
2790 return ftrace_match(str
, regex
, len
, type
);
2794 match_records(struct ftrace_hash
*hash
, char *buff
,
2795 int len
, char *mod
, int not)
2797 unsigned search_len
= 0;
2798 struct ftrace_page
*pg
;
2799 struct dyn_ftrace
*rec
;
2800 int type
= MATCH_FULL
;
2801 char *search
= buff
;
2806 type
= filter_parse_regex(buff
, len
, &search
, ¬);
2807 search_len
= strlen(search
);
2810 mutex_lock(&ftrace_lock
);
2812 if (unlikely(ftrace_disabled
))
2815 do_for_each_ftrace_rec(pg
, rec
) {
2816 if (ftrace_match_record(rec
, mod
, search
, search_len
, type
)) {
2817 ret
= enter_record(hash
, rec
, not);
2824 } while_for_each_ftrace_rec();
2826 mutex_unlock(&ftrace_lock
);
2832 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
2834 return match_records(hash
, buff
, len
, NULL
, 0);
2838 ftrace_match_module_records(struct ftrace_hash
*hash
, char *buff
, char *mod
)
2842 /* blank or '*' mean the same */
2843 if (strcmp(buff
, "*") == 0)
2846 /* handle the case of 'dont filter this module' */
2847 if (strcmp(buff
, "!") == 0 || strcmp(buff
, "!*") == 0) {
2852 return match_records(hash
, buff
, strlen(buff
), mod
, not);
2856 * We register the module command as a template to show others how
2857 * to register the a command as well.
2861 ftrace_mod_callback(struct ftrace_hash
*hash
,
2862 char *func
, char *cmd
, char *param
, int enable
)
2868 * cmd == 'mod' because we only registered this func
2869 * for the 'mod' ftrace_func_command.
2870 * But if you register one func with multiple commands,
2871 * you can tell which command was used by the cmd
2875 /* we must have a module name */
2879 mod
= strsep(¶m
, ":");
2883 ret
= ftrace_match_module_records(hash
, func
, mod
);
2892 static struct ftrace_func_command ftrace_mod_cmd
= {
2894 .func
= ftrace_mod_callback
,
2897 static int __init
ftrace_mod_cmd_init(void)
2899 return register_ftrace_command(&ftrace_mod_cmd
);
2901 core_initcall(ftrace_mod_cmd_init
);
2903 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
2904 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
2906 struct ftrace_func_probe
*entry
;
2907 struct hlist_head
*hhd
;
2910 key
= hash_long(ip
, FTRACE_HASH_BITS
);
2912 hhd
= &ftrace_func_hash
[key
];
2914 if (hlist_empty(hhd
))
2918 * Disable preemption for these calls to prevent a RCU grace
2919 * period. This syncs the hash iteration and freeing of items
2920 * on the hash. rcu_read_lock is too dangerous here.
2922 preempt_disable_notrace();
2923 hlist_for_each_entry_rcu(entry
, hhd
, node
) {
2924 if (entry
->ip
== ip
)
2925 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
2927 preempt_enable_notrace();
2930 static struct ftrace_ops trace_probe_ops __read_mostly
=
2932 .func
= function_trace_probe_call
,
2933 .flags
= FTRACE_OPS_FL_INITIALIZED
,
2934 INIT_REGEX_LOCK(trace_probe_ops
)
2937 static int ftrace_probe_registered
;
2939 static void __enable_ftrace_function_probe(void)
2944 if (ftrace_probe_registered
)
2947 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
2948 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
2952 /* Nothing registered? */
2953 if (i
== FTRACE_FUNC_HASHSIZE
)
2956 ret
= __register_ftrace_function(&trace_probe_ops
);
2958 ret
= ftrace_startup(&trace_probe_ops
, 0);
2960 ftrace_probe_registered
= 1;
2963 static void __disable_ftrace_function_probe(void)
2968 if (!ftrace_probe_registered
)
2971 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
2972 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
2977 /* no more funcs left */
2978 ret
= __unregister_ftrace_function(&trace_probe_ops
);
2980 ftrace_shutdown(&trace_probe_ops
, 0);
2982 ftrace_probe_registered
= 0;
2986 static void ftrace_free_entry(struct ftrace_func_probe
*entry
)
2988 if (entry
->ops
->free
)
2989 entry
->ops
->free(entry
->ops
, entry
->ip
, &entry
->data
);
2994 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
2997 struct ftrace_func_probe
*entry
;
2998 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.filter_hash
;
2999 struct ftrace_hash
*hash
;
3000 struct ftrace_page
*pg
;
3001 struct dyn_ftrace
*rec
;
3008 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3009 len
= strlen(search
);
3011 /* we do not support '!' for function probes */
3015 mutex_lock(&trace_probe_ops
.regex_lock
);
3017 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3023 if (unlikely(ftrace_disabled
)) {
3028 do_for_each_ftrace_rec(pg
, rec
) {
3030 if (!ftrace_match_record(rec
, NULL
, search
, len
, type
))
3033 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3035 /* If we did not process any, then return error */
3046 * The caller might want to do something special
3047 * for each function we find. We call the callback
3048 * to give the caller an opportunity to do so.
3051 if (ops
->init(ops
, rec
->ip
, &entry
->data
) < 0) {
3052 /* caller does not like this func */
3058 ret
= enter_record(hash
, rec
, 0);
3066 entry
->ip
= rec
->ip
;
3068 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3069 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3071 } while_for_each_ftrace_rec();
3073 mutex_lock(&ftrace_lock
);
3074 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3078 __enable_ftrace_function_probe();
3079 mutex_unlock(&ftrace_lock
);
3082 mutex_unlock(&trace_probe_ops
.regex_lock
);
3083 free_ftrace_hash(hash
);
3089 PROBE_TEST_FUNC
= 1,
3094 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3095 void *data
, int flags
)
3097 struct ftrace_func_entry
*rec_entry
;
3098 struct ftrace_func_probe
*entry
;
3099 struct ftrace_func_probe
*p
;
3100 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.filter_hash
;
3101 struct list_head free_list
;
3102 struct ftrace_hash
*hash
;
3103 struct hlist_node
*tmp
;
3104 char str
[KSYM_SYMBOL_LEN
];
3105 int type
= MATCH_FULL
;
3109 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3114 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3115 len
= strlen(search
);
3117 /* 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
);
3126 /* Hmm, should report this somehow */
3129 INIT_LIST_HEAD(&free_list
);
3131 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3132 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3134 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3136 /* break up if statements for readability */
3137 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3140 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3143 /* do this last, since it is the most expensive */
3145 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3147 if (!ftrace_match(str
, glob
, len
, type
))
3151 rec_entry
= ftrace_lookup_ip(hash
, entry
->ip
);
3152 /* It is possible more than one entry had this ip */
3154 free_hash_entry(hash
, rec_entry
);
3156 hlist_del_rcu(&entry
->node
);
3157 list_add(&entry
->free_list
, &free_list
);
3160 mutex_lock(&ftrace_lock
);
3161 __disable_ftrace_function_probe();
3163 * Remove after the disable is called. Otherwise, if the last
3164 * probe is removed, a null hash means *all enabled*.
3166 ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3167 synchronize_sched();
3168 list_for_each_entry_safe(entry
, p
, &free_list
, free_list
) {
3169 list_del(&entry
->free_list
);
3170 ftrace_free_entry(entry
);
3172 mutex_unlock(&ftrace_lock
);
3175 mutex_unlock(&trace_probe_ops
.regex_lock
);
3176 free_ftrace_hash(hash
);
3180 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3183 __unregister_ftrace_function_probe(glob
, ops
, data
,
3184 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3188 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3190 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3193 void unregister_ftrace_function_probe_all(char *glob
)
3195 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3198 static LIST_HEAD(ftrace_commands
);
3199 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3201 int register_ftrace_command(struct ftrace_func_command
*cmd
)
3203 struct ftrace_func_command
*p
;
3206 mutex_lock(&ftrace_cmd_mutex
);
3207 list_for_each_entry(p
, &ftrace_commands
, list
) {
3208 if (strcmp(cmd
->name
, p
->name
) == 0) {
3213 list_add(&cmd
->list
, &ftrace_commands
);
3215 mutex_unlock(&ftrace_cmd_mutex
);
3220 int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
3222 struct ftrace_func_command
*p
, *n
;
3225 mutex_lock(&ftrace_cmd_mutex
);
3226 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
3227 if (strcmp(cmd
->name
, p
->name
) == 0) {
3229 list_del_init(&p
->list
);
3234 mutex_unlock(&ftrace_cmd_mutex
);
3239 static int ftrace_process_regex(struct ftrace_hash
*hash
,
3240 char *buff
, int len
, int enable
)
3242 char *func
, *command
, *next
= buff
;
3243 struct ftrace_func_command
*p
;
3246 func
= strsep(&next
, ":");
3249 ret
= ftrace_match_records(hash
, func
, len
);
3259 command
= strsep(&next
, ":");
3261 mutex_lock(&ftrace_cmd_mutex
);
3262 list_for_each_entry(p
, &ftrace_commands
, list
) {
3263 if (strcmp(p
->name
, command
) == 0) {
3264 ret
= p
->func(hash
, func
, command
, next
, enable
);
3269 mutex_unlock(&ftrace_cmd_mutex
);
3275 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
3276 size_t cnt
, loff_t
*ppos
, int enable
)
3278 struct ftrace_iterator
*iter
;
3279 struct trace_parser
*parser
;
3285 if (file
->f_mode
& FMODE_READ
) {
3286 struct seq_file
*m
= file
->private_data
;
3289 iter
= file
->private_data
;
3291 if (unlikely(ftrace_disabled
))
3294 /* iter->hash is a local copy, so we don't need regex_lock */
3296 parser
= &iter
->parser
;
3297 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
3299 if (read
>= 0 && trace_parser_loaded(parser
) &&
3300 !trace_parser_cont(parser
)) {
3301 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
3302 parser
->idx
, enable
);
3303 trace_parser_clear(parser
);
3314 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
3315 size_t cnt
, loff_t
*ppos
)
3317 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
3321 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
3322 size_t cnt
, loff_t
*ppos
)
3324 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
3328 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
3330 struct ftrace_func_entry
*entry
;
3332 if (!ftrace_location(ip
))
3336 entry
= ftrace_lookup_ip(hash
, ip
);
3339 free_hash_entry(hash
, entry
);
3343 return add_hash_entry(hash
, ip
);
3347 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3348 unsigned long ip
, int remove
, int reset
, int enable
)
3350 struct ftrace_hash
**orig_hash
;
3351 struct ftrace_hash
*hash
;
3354 /* All global ops uses the global ops filters */
3355 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
)
3358 if (unlikely(ftrace_disabled
))
3361 mutex_lock(&ops
->regex_lock
);
3364 orig_hash
= &ops
->filter_hash
;
3366 orig_hash
= &ops
->notrace_hash
;
3368 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3371 goto out_regex_unlock
;
3375 ftrace_filter_reset(hash
);
3376 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
3378 goto out_regex_unlock
;
3381 ret
= ftrace_match_addr(hash
, ip
, remove
);
3383 goto out_regex_unlock
;
3386 mutex_lock(&ftrace_lock
);
3387 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3388 if (!ret
&& ops
->flags
& FTRACE_OPS_FL_ENABLED
3390 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3392 mutex_unlock(&ftrace_lock
);
3395 mutex_unlock(&ops
->regex_lock
);
3397 free_ftrace_hash(hash
);
3402 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
3403 int reset
, int enable
)
3405 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
3409 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3410 * @ops - the ops to set the filter with
3411 * @ip - the address to add to or remove from the filter.
3412 * @remove - non zero to remove the ip from the filter
3413 * @reset - non zero to reset all filters before applying this filter.
3415 * Filters denote which functions should be enabled when tracing is enabled
3416 * If @ip is NULL, it failes to update filter.
3418 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
3419 int remove
, int reset
)
3421 ftrace_ops_init(ops
);
3422 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
3424 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
3427 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3428 int reset
, int enable
)
3430 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
3434 * ftrace_set_filter - set a function to filter on in ftrace
3435 * @ops - the ops to set the filter with
3436 * @buf - the string that holds the function filter text.
3437 * @len - the length of the string.
3438 * @reset - non zero to reset all filters before applying this filter.
3440 * Filters denote which functions should be enabled when tracing is enabled.
3441 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3443 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
3446 ftrace_ops_init(ops
);
3447 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
3449 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
3452 * ftrace_set_notrace - set a function to not trace in ftrace
3453 * @ops - the ops to set the notrace filter with
3454 * @buf - the string that holds the function notrace text.
3455 * @len - the length of the string.
3456 * @reset - non zero to reset all filters before applying this filter.
3458 * Notrace Filters denote which functions should not be enabled when tracing
3459 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3462 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
3465 ftrace_ops_init(ops
);
3466 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
3468 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
3470 * ftrace_set_filter - set a function to filter on in ftrace
3471 * @ops - the ops to set the filter with
3472 * @buf - the string that holds the function filter text.
3473 * @len - the length of the string.
3474 * @reset - non zero to reset all filters before applying this filter.
3476 * Filters denote which functions should be enabled when tracing is enabled.
3477 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3479 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
3481 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
3483 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
3486 * ftrace_set_notrace - set a function to not trace in ftrace
3487 * @ops - the ops to set the notrace filter with
3488 * @buf - the string that holds the function notrace text.
3489 * @len - the length of the string.
3490 * @reset - non zero to reset all filters before applying this filter.
3492 * Notrace Filters denote which functions should not be enabled when tracing
3493 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3496 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
3498 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
3500 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
3503 * command line interface to allow users to set filters on boot up.
3505 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3506 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3507 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3509 static int __init
set_ftrace_notrace(char *str
)
3511 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
3514 __setup("ftrace_notrace=", set_ftrace_notrace
);
3516 static int __init
set_ftrace_filter(char *str
)
3518 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
3521 __setup("ftrace_filter=", set_ftrace_filter
);
3523 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3524 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3525 static int ftrace_set_func(unsigned long *array
, int *idx
, char *buffer
);
3527 static int __init
set_graph_function(char *str
)
3529 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
3532 __setup("ftrace_graph_filter=", set_graph_function
);
3534 static void __init
set_ftrace_early_graph(char *buf
)
3540 func
= strsep(&buf
, ",");
3541 /* we allow only one expression at a time */
3542 ret
= ftrace_set_func(ftrace_graph_funcs
, &ftrace_graph_count
,
3545 printk(KERN_DEBUG
"ftrace: function %s not "
3546 "traceable\n", func
);
3549 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3552 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
3556 ftrace_ops_init(ops
);
3559 func
= strsep(&buf
, ",");
3560 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
3564 static void __init
set_ftrace_early_filters(void)
3566 if (ftrace_filter_buf
[0])
3567 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
3568 if (ftrace_notrace_buf
[0])
3569 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
3570 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3571 if (ftrace_graph_buf
[0])
3572 set_ftrace_early_graph(ftrace_graph_buf
);
3573 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3576 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
3578 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
3579 struct ftrace_iterator
*iter
;
3580 struct ftrace_hash
**orig_hash
;
3581 struct trace_parser
*parser
;
3585 if (file
->f_mode
& FMODE_READ
) {
3587 seq_release(inode
, file
);
3589 iter
= file
->private_data
;
3591 parser
= &iter
->parser
;
3592 if (trace_parser_loaded(parser
)) {
3593 parser
->buffer
[parser
->idx
] = 0;
3594 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
3597 trace_parser_put(parser
);
3599 mutex_lock(&iter
->ops
->regex_lock
);
3601 if (file
->f_mode
& FMODE_WRITE
) {
3602 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
3605 orig_hash
= &iter
->ops
->filter_hash
;
3607 orig_hash
= &iter
->ops
->notrace_hash
;
3609 mutex_lock(&ftrace_lock
);
3610 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
3611 orig_hash
, iter
->hash
);
3612 if (!ret
&& (iter
->ops
->flags
& FTRACE_OPS_FL_ENABLED
)
3614 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3616 mutex_unlock(&ftrace_lock
);
3619 mutex_unlock(&iter
->ops
->regex_lock
);
3620 free_ftrace_hash(iter
->hash
);
3626 static const struct file_operations ftrace_avail_fops
= {
3627 .open
= ftrace_avail_open
,
3629 .llseek
= seq_lseek
,
3630 .release
= seq_release_private
,
3633 static const struct file_operations ftrace_enabled_fops
= {
3634 .open
= ftrace_enabled_open
,
3636 .llseek
= seq_lseek
,
3637 .release
= seq_release_private
,
3640 static const struct file_operations ftrace_filter_fops
= {
3641 .open
= ftrace_filter_open
,
3643 .write
= ftrace_filter_write
,
3644 .llseek
= ftrace_filter_lseek
,
3645 .release
= ftrace_regex_release
,
3648 static const struct file_operations ftrace_notrace_fops
= {
3649 .open
= ftrace_notrace_open
,
3651 .write
= ftrace_notrace_write
,
3652 .llseek
= ftrace_filter_lseek
,
3653 .release
= ftrace_regex_release
,
3656 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3658 static DEFINE_MUTEX(graph_lock
);
3660 int ftrace_graph_count
;
3661 int ftrace_graph_filter_enabled
;
3662 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
3665 __g_next(struct seq_file
*m
, loff_t
*pos
)
3667 if (*pos
>= ftrace_graph_count
)
3669 return &ftrace_graph_funcs
[*pos
];
3673 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3676 return __g_next(m
, pos
);
3679 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
3681 mutex_lock(&graph_lock
);
3683 /* Nothing, tell g_show to print all functions are enabled */
3684 if (!ftrace_graph_filter_enabled
&& !*pos
)
3687 return __g_next(m
, pos
);
3690 static void g_stop(struct seq_file
*m
, void *p
)
3692 mutex_unlock(&graph_lock
);
3695 static int g_show(struct seq_file
*m
, void *v
)
3697 unsigned long *ptr
= v
;
3702 if (ptr
== (unsigned long *)1) {
3703 seq_printf(m
, "#### all functions enabled ####\n");
3707 seq_printf(m
, "%ps\n", (void *)*ptr
);
3712 static const struct seq_operations ftrace_graph_seq_ops
= {
3720 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
3724 if (unlikely(ftrace_disabled
))
3727 mutex_lock(&graph_lock
);
3728 if ((file
->f_mode
& FMODE_WRITE
) &&
3729 (file
->f_flags
& O_TRUNC
)) {
3730 ftrace_graph_filter_enabled
= 0;
3731 ftrace_graph_count
= 0;
3732 memset(ftrace_graph_funcs
, 0, sizeof(ftrace_graph_funcs
));
3734 mutex_unlock(&graph_lock
);
3736 if (file
->f_mode
& FMODE_READ
)
3737 ret
= seq_open(file
, &ftrace_graph_seq_ops
);
3743 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
3745 if (file
->f_mode
& FMODE_READ
)
3746 seq_release(inode
, file
);
3751 ftrace_set_func(unsigned long *array
, int *idx
, char *buffer
)
3753 struct dyn_ftrace
*rec
;
3754 struct ftrace_page
*pg
;
3763 type
= filter_parse_regex(buffer
, strlen(buffer
), &search
, ¬);
3764 if (!not && *idx
>= FTRACE_GRAPH_MAX_FUNCS
)
3767 search_len
= strlen(search
);
3769 mutex_lock(&ftrace_lock
);
3771 if (unlikely(ftrace_disabled
)) {
3772 mutex_unlock(&ftrace_lock
);
3776 do_for_each_ftrace_rec(pg
, rec
) {
3778 if (ftrace_match_record(rec
, NULL
, search
, search_len
, type
)) {
3779 /* if it is in the array */
3781 for (i
= 0; i
< *idx
; i
++) {
3782 if (array
[i
] == rec
->ip
) {
3791 array
[(*idx
)++] = rec
->ip
;
3792 if (*idx
>= FTRACE_GRAPH_MAX_FUNCS
)
3797 array
[i
] = array
[--(*idx
)];
3803 } while_for_each_ftrace_rec();
3805 mutex_unlock(&ftrace_lock
);
3810 ftrace_graph_filter_enabled
= !!(*idx
);
3816 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
3817 size_t cnt
, loff_t
*ppos
)
3819 struct trace_parser parser
;
3825 mutex_lock(&graph_lock
);
3827 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
)) {
3832 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
3834 if (read
>= 0 && trace_parser_loaded((&parser
))) {
3835 parser
.buffer
[parser
.idx
] = 0;
3837 /* we allow only one expression at a time */
3838 ret
= ftrace_set_func(ftrace_graph_funcs
, &ftrace_graph_count
,
3847 trace_parser_put(&parser
);
3849 mutex_unlock(&graph_lock
);
3854 static const struct file_operations ftrace_graph_fops
= {
3855 .open
= ftrace_graph_open
,
3857 .write
= ftrace_graph_write
,
3858 .llseek
= ftrace_filter_lseek
,
3859 .release
= ftrace_graph_release
,
3861 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3863 static __init
int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
)
3866 trace_create_file("available_filter_functions", 0444,
3867 d_tracer
, NULL
, &ftrace_avail_fops
);
3869 trace_create_file("enabled_functions", 0444,
3870 d_tracer
, NULL
, &ftrace_enabled_fops
);
3872 trace_create_file("set_ftrace_filter", 0644, d_tracer
,
3873 NULL
, &ftrace_filter_fops
);
3875 trace_create_file("set_ftrace_notrace", 0644, d_tracer
,
3876 NULL
, &ftrace_notrace_fops
);
3878 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3879 trace_create_file("set_graph_function", 0444, d_tracer
,
3881 &ftrace_graph_fops
);
3882 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3887 static int ftrace_cmp_ips(const void *a
, const void *b
)
3889 const unsigned long *ipa
= a
;
3890 const unsigned long *ipb
= b
;
3899 static void ftrace_swap_ips(void *a
, void *b
, int size
)
3901 unsigned long *ipa
= a
;
3902 unsigned long *ipb
= b
;
3910 static int ftrace_process_locs(struct module
*mod
,
3911 unsigned long *start
,
3914 struct ftrace_page
*start_pg
;
3915 struct ftrace_page
*pg
;
3916 struct dyn_ftrace
*rec
;
3917 unsigned long count
;
3920 unsigned long flags
= 0; /* Shut up gcc */
3923 count
= end
- start
;
3928 sort(start
, count
, sizeof(*start
),
3929 ftrace_cmp_ips
, ftrace_swap_ips
);
3931 start_pg
= ftrace_allocate_pages(count
);
3935 mutex_lock(&ftrace_lock
);
3938 * Core and each module needs their own pages, as
3939 * modules will free them when they are removed.
3940 * Force a new page to be allocated for modules.
3943 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
3944 /* First initialization */
3945 ftrace_pages
= ftrace_pages_start
= start_pg
;
3950 if (WARN_ON(ftrace_pages
->next
)) {
3951 /* Hmm, we have free pages? */
3952 while (ftrace_pages
->next
)
3953 ftrace_pages
= ftrace_pages
->next
;
3956 ftrace_pages
->next
= start_pg
;
3962 addr
= ftrace_call_adjust(*p
++);
3964 * Some architecture linkers will pad between
3965 * the different mcount_loc sections of different
3966 * object files to satisfy alignments.
3967 * Skip any NULL pointers.
3972 if (pg
->index
== pg
->size
) {
3973 /* We should have allocated enough */
3974 if (WARN_ON(!pg
->next
))
3979 rec
= &pg
->records
[pg
->index
++];
3983 /* We should have used all pages */
3986 /* Assign the last page to ftrace_pages */
3989 /* These new locations need to be initialized */
3990 ftrace_new_pgs
= start_pg
;
3993 * We only need to disable interrupts on start up
3994 * because we are modifying code that an interrupt
3995 * may execute, and the modification is not atomic.
3996 * But for modules, nothing runs the code we modify
3997 * until we are finished with it, and there's no
3998 * reason to cause large interrupt latencies while we do it.
4001 local_irq_save(flags
);
4002 ftrace_update_code(mod
);
4004 local_irq_restore(flags
);
4007 mutex_unlock(&ftrace_lock
);
4012 #ifdef CONFIG_MODULES
4014 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4016 void ftrace_release_mod(struct module
*mod
)
4018 struct dyn_ftrace
*rec
;
4019 struct ftrace_page
**last_pg
;
4020 struct ftrace_page
*pg
;
4023 mutex_lock(&ftrace_lock
);
4025 if (ftrace_disabled
)
4029 * Each module has its own ftrace_pages, remove
4030 * them from the list.
4032 last_pg
= &ftrace_pages_start
;
4033 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
4034 rec
= &pg
->records
[0];
4035 if (within_module_core(rec
->ip
, mod
)) {
4037 * As core pages are first, the first
4038 * page should never be a module page.
4040 if (WARN_ON(pg
== ftrace_pages_start
))
4043 /* Check if we are deleting the last page */
4044 if (pg
== ftrace_pages
)
4045 ftrace_pages
= next_to_ftrace_page(last_pg
);
4047 *last_pg
= pg
->next
;
4048 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
4049 free_pages((unsigned long)pg
->records
, order
);
4052 last_pg
= &pg
->next
;
4055 mutex_unlock(&ftrace_lock
);
4058 static void ftrace_init_module(struct module
*mod
,
4059 unsigned long *start
, unsigned long *end
)
4061 if (ftrace_disabled
|| start
== end
)
4063 ftrace_process_locs(mod
, start
, end
);
4066 static int ftrace_module_notify_enter(struct notifier_block
*self
,
4067 unsigned long val
, void *data
)
4069 struct module
*mod
= data
;
4071 if (val
== MODULE_STATE_COMING
)
4072 ftrace_init_module(mod
, mod
->ftrace_callsites
,
4073 mod
->ftrace_callsites
+
4074 mod
->num_ftrace_callsites
);
4078 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4079 unsigned long val
, void *data
)
4081 struct module
*mod
= data
;
4083 if (val
== MODULE_STATE_GOING
)
4084 ftrace_release_mod(mod
);
4089 static int ftrace_module_notify_enter(struct notifier_block
*self
,
4090 unsigned long val
, void *data
)
4094 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4095 unsigned long val
, void *data
)
4099 #endif /* CONFIG_MODULES */
4101 struct notifier_block ftrace_module_enter_nb
= {
4102 .notifier_call
= ftrace_module_notify_enter
,
4103 .priority
= INT_MAX
, /* Run before anything that can use kprobes */
4106 struct notifier_block ftrace_module_exit_nb
= {
4107 .notifier_call
= ftrace_module_notify_exit
,
4108 .priority
= INT_MIN
, /* Run after anything that can remove kprobes */
4111 extern unsigned long __start_mcount_loc
[];
4112 extern unsigned long __stop_mcount_loc
[];
4114 void __init
ftrace_init(void)
4116 unsigned long count
, addr
, flags
;
4119 /* Keep the ftrace pointer to the stub */
4120 addr
= (unsigned long)ftrace_stub
;
4122 local_irq_save(flags
);
4123 ftrace_dyn_arch_init(&addr
);
4124 local_irq_restore(flags
);
4126 /* ftrace_dyn_arch_init places the return code in addr */
4130 count
= __stop_mcount_loc
- __start_mcount_loc
;
4132 ret
= ftrace_dyn_table_alloc(count
);
4136 last_ftrace_enabled
= ftrace_enabled
= 1;
4138 ret
= ftrace_process_locs(NULL
,
4142 ret
= register_module_notifier(&ftrace_module_enter_nb
);
4144 pr_warning("Failed to register trace ftrace module enter notifier\n");
4146 ret
= register_module_notifier(&ftrace_module_exit_nb
);
4148 pr_warning("Failed to register trace ftrace module exit notifier\n");
4150 set_ftrace_early_filters();
4154 ftrace_disabled
= 1;
4159 static struct ftrace_ops global_ops
= {
4160 .func
= ftrace_stub
,
4161 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4162 INIT_REGEX_LOCK(global_ops
)
4165 static int __init
ftrace_nodyn_init(void)
4170 core_initcall(ftrace_nodyn_init
);
4172 static inline int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
) { return 0; }
4173 static inline void ftrace_startup_enable(int command
) { }
4174 /* Keep as macros so we do not need to define the commands */
4175 # define ftrace_startup(ops, command) \
4177 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4180 # define ftrace_shutdown(ops, command) do { } while (0)
4181 # define ftrace_startup_sysctl() do { } while (0)
4182 # define ftrace_shutdown_sysctl() do { } while (0)
4185 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
)
4190 #endif /* CONFIG_DYNAMIC_FTRACE */
4193 ftrace_ops_control_func(unsigned long ip
, unsigned long parent_ip
,
4194 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4196 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT
)))
4200 * Some of the ops may be dynamically allocated,
4201 * they must be freed after a synchronize_sched().
4203 preempt_disable_notrace();
4204 trace_recursion_set(TRACE_CONTROL_BIT
);
4205 do_for_each_ftrace_op(op
, ftrace_control_list
) {
4206 if (!(op
->flags
& FTRACE_OPS_FL_STUB
) &&
4207 !ftrace_function_local_disabled(op
) &&
4208 ftrace_ops_test(op
, ip
))
4209 op
->func(ip
, parent_ip
, op
, regs
);
4210 } while_for_each_ftrace_op(op
);
4211 trace_recursion_clear(TRACE_CONTROL_BIT
);
4212 preempt_enable_notrace();
4215 static struct ftrace_ops control_ops
= {
4216 .func
= ftrace_ops_control_func
,
4217 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4218 INIT_REGEX_LOCK(control_ops
)
4222 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4223 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
4225 struct ftrace_ops
*op
;
4228 if (function_trace_stop
)
4231 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
4236 * Some of the ops may be dynamically allocated,
4237 * they must be freed after a synchronize_sched().
4239 preempt_disable_notrace();
4240 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4241 if (ftrace_ops_test(op
, ip
))
4242 op
->func(ip
, parent_ip
, op
, regs
);
4243 } while_for_each_ftrace_op(op
);
4244 preempt_enable_notrace();
4245 trace_clear_recursion(bit
);
4249 * Some archs only support passing ip and parent_ip. Even though
4250 * the list function ignores the op parameter, we do not want any
4251 * C side effects, where a function is called without the caller
4252 * sending a third parameter.
4253 * Archs are to support both the regs and ftrace_ops at the same time.
4254 * If they support ftrace_ops, it is assumed they support regs.
4255 * If call backs want to use regs, they must either check for regs
4256 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4257 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4258 * An architecture can pass partial regs with ftrace_ops and still
4259 * set the ARCH_SUPPORT_FTARCE_OPS.
4261 #if ARCH_SUPPORTS_FTRACE_OPS
4262 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4263 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4265 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
4268 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
4270 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
4274 static void clear_ftrace_swapper(void)
4276 struct task_struct
*p
;
4280 for_each_online_cpu(cpu
) {
4282 clear_tsk_trace_trace(p
);
4287 static void set_ftrace_swapper(void)
4289 struct task_struct
*p
;
4293 for_each_online_cpu(cpu
) {
4295 set_tsk_trace_trace(p
);
4300 static void clear_ftrace_pid(struct pid
*pid
)
4302 struct task_struct
*p
;
4305 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4306 clear_tsk_trace_trace(p
);
4307 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4313 static void set_ftrace_pid(struct pid
*pid
)
4315 struct task_struct
*p
;
4318 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4319 set_tsk_trace_trace(p
);
4320 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4324 static void clear_ftrace_pid_task(struct pid
*pid
)
4326 if (pid
== ftrace_swapper_pid
)
4327 clear_ftrace_swapper();
4329 clear_ftrace_pid(pid
);
4332 static void set_ftrace_pid_task(struct pid
*pid
)
4334 if (pid
== ftrace_swapper_pid
)
4335 set_ftrace_swapper();
4337 set_ftrace_pid(pid
);
4340 static int ftrace_pid_add(int p
)
4343 struct ftrace_pid
*fpid
;
4346 mutex_lock(&ftrace_lock
);
4349 pid
= ftrace_swapper_pid
;
4351 pid
= find_get_pid(p
);
4358 list_for_each_entry(fpid
, &ftrace_pids
, list
)
4359 if (fpid
->pid
== pid
)
4364 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
4368 list_add(&fpid
->list
, &ftrace_pids
);
4371 set_ftrace_pid_task(pid
);
4373 ftrace_update_pid_func();
4374 ftrace_startup_enable(0);
4376 mutex_unlock(&ftrace_lock
);
4380 if (pid
!= ftrace_swapper_pid
)
4384 mutex_unlock(&ftrace_lock
);
4388 static void ftrace_pid_reset(void)
4390 struct ftrace_pid
*fpid
, *safe
;
4392 mutex_lock(&ftrace_lock
);
4393 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
4394 struct pid
*pid
= fpid
->pid
;
4396 clear_ftrace_pid_task(pid
);
4398 list_del(&fpid
->list
);
4402 ftrace_update_pid_func();
4403 ftrace_startup_enable(0);
4405 mutex_unlock(&ftrace_lock
);
4408 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
4410 mutex_lock(&ftrace_lock
);
4412 if (list_empty(&ftrace_pids
) && (!*pos
))
4415 return seq_list_start(&ftrace_pids
, *pos
);
4418 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4423 return seq_list_next(v
, &ftrace_pids
, pos
);
4426 static void fpid_stop(struct seq_file
*m
, void *p
)
4428 mutex_unlock(&ftrace_lock
);
4431 static int fpid_show(struct seq_file
*m
, void *v
)
4433 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
4435 if (v
== (void *)1) {
4436 seq_printf(m
, "no pid\n");
4440 if (fpid
->pid
== ftrace_swapper_pid
)
4441 seq_printf(m
, "swapper tasks\n");
4443 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
4448 static const struct seq_operations ftrace_pid_sops
= {
4449 .start
= fpid_start
,
4456 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
4460 if ((file
->f_mode
& FMODE_WRITE
) &&
4461 (file
->f_flags
& O_TRUNC
))
4464 if (file
->f_mode
& FMODE_READ
)
4465 ret
= seq_open(file
, &ftrace_pid_sops
);
4471 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
4472 size_t cnt
, loff_t
*ppos
)
4478 if (cnt
>= sizeof(buf
))
4481 if (copy_from_user(&buf
, ubuf
, cnt
))
4487 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4488 * to clean the filter quietly.
4490 tmp
= strstrip(buf
);
4491 if (strlen(tmp
) == 0)
4494 ret
= kstrtol(tmp
, 10, &val
);
4498 ret
= ftrace_pid_add(val
);
4500 return ret
? ret
: cnt
;
4504 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
4506 if (file
->f_mode
& FMODE_READ
)
4507 seq_release(inode
, file
);
4512 static const struct file_operations ftrace_pid_fops
= {
4513 .open
= ftrace_pid_open
,
4514 .write
= ftrace_pid_write
,
4516 .llseek
= ftrace_filter_lseek
,
4517 .release
= ftrace_pid_release
,
4520 static __init
int ftrace_init_debugfs(void)
4522 struct dentry
*d_tracer
;
4524 d_tracer
= tracing_init_dentry();
4528 ftrace_init_dyn_debugfs(d_tracer
);
4530 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
4531 NULL
, &ftrace_pid_fops
);
4533 ftrace_profile_debugfs(d_tracer
);
4537 fs_initcall(ftrace_init_debugfs
);
4540 * ftrace_kill - kill ftrace
4542 * This function should be used by panic code. It stops ftrace
4543 * but in a not so nice way. If you need to simply kill ftrace
4544 * from a non-atomic section, use ftrace_kill.
4546 void ftrace_kill(void)
4548 ftrace_disabled
= 1;
4550 clear_ftrace_function();
4554 * Test if ftrace is dead or not.
4556 int ftrace_is_dead(void)
4558 return ftrace_disabled
;
4562 * register_ftrace_function - register a function for profiling
4563 * @ops - ops structure that holds the function for profiling.
4565 * Register a function to be called by all functions in the
4568 * Note: @ops->func and all the functions it calls must be labeled
4569 * with "notrace", otherwise it will go into a
4572 int register_ftrace_function(struct ftrace_ops
*ops
)
4576 ftrace_ops_init(ops
);
4578 mutex_lock(&ftrace_lock
);
4580 ret
= __register_ftrace_function(ops
);
4582 ret
= ftrace_startup(ops
, 0);
4584 mutex_unlock(&ftrace_lock
);
4588 EXPORT_SYMBOL_GPL(register_ftrace_function
);
4591 * unregister_ftrace_function - unregister a function for profiling.
4592 * @ops - ops structure that holds the function to unregister
4594 * Unregister a function that was added to be called by ftrace profiling.
4596 int unregister_ftrace_function(struct ftrace_ops
*ops
)
4600 mutex_lock(&ftrace_lock
);
4601 ret
= __unregister_ftrace_function(ops
);
4603 ftrace_shutdown(ops
, 0);
4604 mutex_unlock(&ftrace_lock
);
4608 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
4611 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
4612 void __user
*buffer
, size_t *lenp
,
4617 mutex_lock(&ftrace_lock
);
4619 if (unlikely(ftrace_disabled
))
4622 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
4624 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
4627 last_ftrace_enabled
= !!ftrace_enabled
;
4629 if (ftrace_enabled
) {
4631 ftrace_startup_sysctl();
4633 /* we are starting ftrace again */
4634 if (ftrace_ops_list
!= &ftrace_list_end
)
4635 update_ftrace_function();
4638 /* stopping ftrace calls (just send to ftrace_stub) */
4639 ftrace_trace_function
= ftrace_stub
;
4641 ftrace_shutdown_sysctl();
4645 mutex_unlock(&ftrace_lock
);
4649 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4651 static int ftrace_graph_active
;
4652 static struct notifier_block ftrace_suspend_notifier
;
4654 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
4659 /* The callbacks that hook a function */
4660 trace_func_graph_ret_t ftrace_graph_return
=
4661 (trace_func_graph_ret_t
)ftrace_stub
;
4662 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
4664 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
4665 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
4669 unsigned long flags
;
4670 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
4671 struct task_struct
*g
, *t
;
4673 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
4674 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
4675 * sizeof(struct ftrace_ret_stack
),
4677 if (!ret_stack_list
[i
]) {
4685 read_lock_irqsave(&tasklist_lock
, flags
);
4686 do_each_thread(g
, t
) {
4692 if (t
->ret_stack
== NULL
) {
4693 atomic_set(&t
->tracing_graph_pause
, 0);
4694 atomic_set(&t
->trace_overrun
, 0);
4695 t
->curr_ret_stack
= -1;
4696 /* Make sure the tasks see the -1 first: */
4698 t
->ret_stack
= ret_stack_list
[start
++];
4700 } while_each_thread(g
, t
);
4703 read_unlock_irqrestore(&tasklist_lock
, flags
);
4705 for (i
= start
; i
< end
; i
++)
4706 kfree(ret_stack_list
[i
]);
4711 ftrace_graph_probe_sched_switch(void *ignore
,
4712 struct task_struct
*prev
, struct task_struct
*next
)
4714 unsigned long long timestamp
;
4718 * Does the user want to count the time a function was asleep.
4719 * If so, do not update the time stamps.
4721 if (trace_flags
& TRACE_ITER_SLEEP_TIME
)
4724 timestamp
= trace_clock_local();
4726 prev
->ftrace_timestamp
= timestamp
;
4728 /* only process tasks that we timestamped */
4729 if (!next
->ftrace_timestamp
)
4733 * Update all the counters in next to make up for the
4734 * time next was sleeping.
4736 timestamp
-= next
->ftrace_timestamp
;
4738 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
4739 next
->ret_stack
[index
].calltime
+= timestamp
;
4742 /* Allocate a return stack for each task */
4743 static int start_graph_tracing(void)
4745 struct ftrace_ret_stack
**ret_stack_list
;
4748 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
4749 sizeof(struct ftrace_ret_stack
*),
4752 if (!ret_stack_list
)
4755 /* The cpu_boot init_task->ret_stack will never be freed */
4756 for_each_online_cpu(cpu
) {
4757 if (!idle_task(cpu
)->ret_stack
)
4758 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
4762 ret
= alloc_retstack_tasklist(ret_stack_list
);
4763 } while (ret
== -EAGAIN
);
4766 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
4768 pr_info("ftrace_graph: Couldn't activate tracepoint"
4769 " probe to kernel_sched_switch\n");
4772 kfree(ret_stack_list
);
4777 * Hibernation protection.
4778 * The state of the current task is too much unstable during
4779 * suspend/restore to disk. We want to protect against that.
4782 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
4786 case PM_HIBERNATION_PREPARE
:
4787 pause_graph_tracing();
4790 case PM_POST_HIBERNATION
:
4791 unpause_graph_tracing();
4797 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
4798 trace_func_graph_ent_t entryfunc
)
4802 mutex_lock(&ftrace_lock
);
4804 /* we currently allow only one tracer registered at a time */
4805 if (ftrace_graph_active
) {
4810 ftrace_suspend_notifier
.notifier_call
= ftrace_suspend_notifier_call
;
4811 register_pm_notifier(&ftrace_suspend_notifier
);
4813 ftrace_graph_active
++;
4814 ret
= start_graph_tracing();
4816 ftrace_graph_active
--;
4820 ftrace_graph_return
= retfunc
;
4821 ftrace_graph_entry
= entryfunc
;
4823 ret
= ftrace_startup(&global_ops
, FTRACE_START_FUNC_RET
);
4826 mutex_unlock(&ftrace_lock
);
4830 void unregister_ftrace_graph(void)
4832 mutex_lock(&ftrace_lock
);
4834 if (unlikely(!ftrace_graph_active
))
4837 ftrace_graph_active
--;
4838 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
4839 ftrace_graph_entry
= ftrace_graph_entry_stub
;
4840 ftrace_shutdown(&global_ops
, FTRACE_STOP_FUNC_RET
);
4841 unregister_pm_notifier(&ftrace_suspend_notifier
);
4842 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
4845 mutex_unlock(&ftrace_lock
);
4848 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
4851 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
4853 atomic_set(&t
->tracing_graph_pause
, 0);
4854 atomic_set(&t
->trace_overrun
, 0);
4855 t
->ftrace_timestamp
= 0;
4856 /* make curr_ret_stack visible before we add the ret_stack */
4858 t
->ret_stack
= ret_stack
;
4862 * Allocate a return stack for the idle task. May be the first
4863 * time through, or it may be done by CPU hotplug online.
4865 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
4867 t
->curr_ret_stack
= -1;
4869 * The idle task has no parent, it either has its own
4870 * stack or no stack at all.
4873 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
4875 if (ftrace_graph_active
) {
4876 struct ftrace_ret_stack
*ret_stack
;
4878 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
4880 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
4881 * sizeof(struct ftrace_ret_stack
),
4885 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
4887 graph_init_task(t
, ret_stack
);
4891 /* Allocate a return stack for newly created task */
4892 void ftrace_graph_init_task(struct task_struct
*t
)
4894 /* Make sure we do not use the parent ret_stack */
4895 t
->ret_stack
= NULL
;
4896 t
->curr_ret_stack
= -1;
4898 if (ftrace_graph_active
) {
4899 struct ftrace_ret_stack
*ret_stack
;
4901 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
4902 * sizeof(struct ftrace_ret_stack
),
4906 graph_init_task(t
, ret_stack
);
4910 void ftrace_graph_exit_task(struct task_struct
*t
)
4912 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
4914 t
->ret_stack
= NULL
;
4915 /* NULL must become visible to IRQs before we free it: */
4921 void ftrace_graph_stop(void)