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
;
88 /* What to set function_trace_op to */
89 static struct ftrace_ops
*set_function_trace_op
;
91 /* List for set_ftrace_pid's pids. */
92 LIST_HEAD(ftrace_pids
);
94 struct list_head list
;
99 * ftrace_disabled is set when an anomaly is discovered.
100 * ftrace_disabled is much stronger than ftrace_enabled.
102 static int ftrace_disabled __read_mostly
;
104 static DEFINE_MUTEX(ftrace_lock
);
106 static struct ftrace_ops
*ftrace_global_list __read_mostly
= &ftrace_list_end
;
107 static struct ftrace_ops
*ftrace_control_list __read_mostly
= &ftrace_list_end
;
108 static struct ftrace_ops
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
109 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
110 ftrace_func_t ftrace_pid_function __read_mostly
= ftrace_stub
;
111 static struct ftrace_ops global_ops
;
112 static struct ftrace_ops control_ops
;
114 #if ARCH_SUPPORTS_FTRACE_OPS
115 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
116 struct ftrace_ops
*op
, struct pt_regs
*regs
);
118 /* See comment below, where ftrace_ops_list_func is defined */
119 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
120 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
124 * Traverse the ftrace_global_list, invoking all entries. The reason that we
125 * can use rcu_dereference_raw_notrace() is that elements removed from this list
126 * are simply leaked, so there is no need to interact with a grace-period
127 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
128 * concurrent insertions into the ftrace_global_list.
130 * Silly Alpha and silly pointer-speculation compiler optimizations!
132 #define do_for_each_ftrace_op(op, list) \
133 op = rcu_dereference_raw_notrace(list); \
137 * Optimized for just a single item in the list (as that is the normal case).
139 #define while_for_each_ftrace_op(op) \
140 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
141 unlikely((op) != &ftrace_list_end))
143 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
145 #ifdef CONFIG_DYNAMIC_FTRACE
146 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
147 mutex_init(&ops
->regex_lock
);
148 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
154 * ftrace_nr_registered_ops - return number of ops registered
156 * Returns the number of ftrace_ops registered and tracing functions
158 int ftrace_nr_registered_ops(void)
160 struct ftrace_ops
*ops
;
163 mutex_lock(&ftrace_lock
);
165 for (ops
= ftrace_ops_list
;
166 ops
!= &ftrace_list_end
; ops
= ops
->next
)
169 mutex_unlock(&ftrace_lock
);
175 ftrace_global_list_func(unsigned long ip
, unsigned long parent_ip
,
176 struct ftrace_ops
*op
, struct pt_regs
*regs
)
180 bit
= trace_test_and_set_recursion(TRACE_GLOBAL_START
, TRACE_GLOBAL_MAX
);
184 do_for_each_ftrace_op(op
, ftrace_global_list
) {
185 op
->func(ip
, parent_ip
, op
, regs
);
186 } while_for_each_ftrace_op(op
);
188 trace_clear_recursion(bit
);
191 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
192 struct ftrace_ops
*op
, struct pt_regs
*regs
)
194 if (!test_tsk_trace_trace(current
))
197 ftrace_pid_function(ip
, parent_ip
, op
, regs
);
200 static void set_ftrace_pid_function(ftrace_func_t func
)
202 /* do not set ftrace_pid_function to itself! */
203 if (func
!= ftrace_pid_func
)
204 ftrace_pid_function
= func
;
208 * clear_ftrace_function - reset the ftrace function
210 * This NULLs the ftrace function and in essence stops
211 * tracing. There may be lag
213 void clear_ftrace_function(void)
215 ftrace_trace_function
= ftrace_stub
;
216 ftrace_pid_function
= ftrace_stub
;
219 static void control_ops_disable_all(struct ftrace_ops
*ops
)
223 for_each_possible_cpu(cpu
)
224 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
227 static int control_ops_alloc(struct ftrace_ops
*ops
)
229 int __percpu
*disabled
;
231 disabled
= alloc_percpu(int);
235 ops
->disabled
= disabled
;
236 control_ops_disable_all(ops
);
240 static void control_ops_free(struct ftrace_ops
*ops
)
242 free_percpu(ops
->disabled
);
245 static void update_global_ops(void)
250 * If there's only one function registered, then call that
251 * function directly. Otherwise, we need to iterate over the
252 * registered callers.
254 if (ftrace_global_list
== &ftrace_list_end
||
255 ftrace_global_list
->next
== &ftrace_list_end
) {
256 func
= ftrace_global_list
->func
;
258 * As we are calling the function directly.
259 * If it does not have recursion protection,
260 * the function_trace_op needs to be updated
263 if (ftrace_global_list
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
)
264 global_ops
.flags
|= FTRACE_OPS_FL_RECURSION_SAFE
;
266 global_ops
.flags
&= ~FTRACE_OPS_FL_RECURSION_SAFE
;
268 func
= ftrace_global_list_func
;
269 /* The list has its own recursion protection. */
270 global_ops
.flags
|= FTRACE_OPS_FL_RECURSION_SAFE
;
274 /* If we filter on pids, update to use the pid function */
275 if (!list_empty(&ftrace_pids
)) {
276 set_ftrace_pid_function(func
);
277 func
= ftrace_pid_func
;
280 global_ops
.func
= func
;
283 static void ftrace_sync(struct work_struct
*work
)
286 * This function is just a stub to implement a hard force
287 * of synchronize_sched(). This requires synchronizing
288 * tasks even in userspace and idle.
290 * Yes, function tracing is rude.
294 static void ftrace_sync_ipi(void *data
)
296 /* Probably not needed, but do it anyway */
300 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
301 static void update_function_graph_func(void);
303 static inline void update_function_graph_func(void) { }
306 static void update_ftrace_function(void)
313 * If we are at the end of the list and this ops is
314 * recursion safe and not dynamic and the arch supports passing ops,
315 * then have the mcount trampoline call the function directly.
317 if (ftrace_ops_list
== &ftrace_list_end
||
318 (ftrace_ops_list
->next
== &ftrace_list_end
&&
319 !(ftrace_ops_list
->flags
& FTRACE_OPS_FL_DYNAMIC
) &&
320 (ftrace_ops_list
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) &&
321 !FTRACE_FORCE_LIST_FUNC
)) {
322 /* Set the ftrace_ops that the arch callback uses */
323 if (ftrace_ops_list
== &global_ops
)
324 set_function_trace_op
= ftrace_global_list
;
326 set_function_trace_op
= ftrace_ops_list
;
327 func
= ftrace_ops_list
->func
;
329 /* Just use the default ftrace_ops */
330 set_function_trace_op
= &ftrace_list_end
;
331 func
= ftrace_ops_list_func
;
334 update_function_graph_func();
336 /* If there's no change, then do nothing more here */
337 if (ftrace_trace_function
== func
)
341 * If we are using the list function, it doesn't care
342 * about the function_trace_ops.
344 if (func
== ftrace_ops_list_func
) {
345 ftrace_trace_function
= func
;
347 * Don't even bother setting function_trace_ops,
348 * it would be racy to do so anyway.
353 #ifndef CONFIG_DYNAMIC_FTRACE
355 * For static tracing, we need to be a bit more careful.
356 * The function change takes affect immediately. Thus,
357 * we need to coorditate the setting of the function_trace_ops
358 * with the setting of the ftrace_trace_function.
360 * Set the function to the list ops, which will call the
361 * function we want, albeit indirectly, but it handles the
362 * ftrace_ops and doesn't depend on function_trace_op.
364 ftrace_trace_function
= ftrace_ops_list_func
;
366 * Make sure all CPUs see this. Yes this is slow, but static
367 * tracing is slow and nasty to have enabled.
369 schedule_on_each_cpu(ftrace_sync
);
370 /* Now all cpus are using the list ops. */
371 function_trace_op
= set_function_trace_op
;
372 /* Make sure the function_trace_op is visible on all CPUs */
374 /* Nasty way to force a rmb on all cpus */
375 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
376 /* OK, we are all set to update the ftrace_trace_function now! */
377 #endif /* !CONFIG_DYNAMIC_FTRACE */
379 ftrace_trace_function
= func
;
382 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
386 * We are entering ops into the list but another
387 * CPU might be walking that list. We need to make sure
388 * the ops->next pointer is valid before another CPU sees
389 * the ops pointer included into the list.
391 rcu_assign_pointer(*list
, ops
);
394 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
396 struct ftrace_ops
**p
;
399 * If we are removing the last function, then simply point
400 * to the ftrace_stub.
402 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
403 *list
= &ftrace_list_end
;
407 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
418 static void add_ftrace_list_ops(struct ftrace_ops
**list
,
419 struct ftrace_ops
*main_ops
,
420 struct ftrace_ops
*ops
)
422 int first
= *list
== &ftrace_list_end
;
423 add_ftrace_ops(list
, ops
);
425 add_ftrace_ops(&ftrace_ops_list
, main_ops
);
428 static int remove_ftrace_list_ops(struct ftrace_ops
**list
,
429 struct ftrace_ops
*main_ops
,
430 struct ftrace_ops
*ops
)
432 int ret
= remove_ftrace_ops(list
, ops
);
433 if (!ret
&& *list
== &ftrace_list_end
)
434 ret
= remove_ftrace_ops(&ftrace_ops_list
, main_ops
);
438 static int __register_ftrace_function(struct ftrace_ops
*ops
)
440 if (FTRACE_WARN_ON(ops
== &global_ops
))
443 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
446 /* We don't support both control and global flags set. */
447 if ((ops
->flags
& FL_GLOBAL_CONTROL_MASK
) == FL_GLOBAL_CONTROL_MASK
)
450 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
452 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
453 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
454 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
456 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
457 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
460 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
461 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
464 if (!core_kernel_data((unsigned long)ops
))
465 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
467 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
468 add_ftrace_list_ops(&ftrace_global_list
, &global_ops
, ops
);
469 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
470 } else if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
471 if (control_ops_alloc(ops
))
473 add_ftrace_list_ops(&ftrace_control_list
, &control_ops
, ops
);
475 add_ftrace_ops(&ftrace_ops_list
, ops
);
478 update_ftrace_function();
483 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
487 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
490 if (FTRACE_WARN_ON(ops
== &global_ops
))
493 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
494 ret
= remove_ftrace_list_ops(&ftrace_global_list
,
497 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
498 } else if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
499 ret
= remove_ftrace_list_ops(&ftrace_control_list
,
502 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
508 update_ftrace_function();
513 static void ftrace_update_pid_func(void)
515 /* Only do something if we are tracing something */
516 if (ftrace_trace_function
== ftrace_stub
)
519 update_ftrace_function();
522 #ifdef CONFIG_FUNCTION_PROFILER
523 struct ftrace_profile
{
524 struct hlist_node node
;
526 unsigned long counter
;
527 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
528 unsigned long long time
;
529 unsigned long long time_squared
;
533 struct ftrace_profile_page
{
534 struct ftrace_profile_page
*next
;
536 struct ftrace_profile records
[];
539 struct ftrace_profile_stat
{
541 struct hlist_head
*hash
;
542 struct ftrace_profile_page
*pages
;
543 struct ftrace_profile_page
*start
;
544 struct tracer_stat stat
;
547 #define PROFILE_RECORDS_SIZE \
548 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
550 #define PROFILES_PER_PAGE \
551 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
553 static int ftrace_profile_enabled __read_mostly
;
555 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
556 static DEFINE_MUTEX(ftrace_profile_lock
);
558 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
560 #define FTRACE_PROFILE_HASH_BITS 10
561 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
564 function_stat_next(void *v
, int idx
)
566 struct ftrace_profile
*rec
= v
;
567 struct ftrace_profile_page
*pg
;
569 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
575 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
579 rec
= &pg
->records
[0];
587 static void *function_stat_start(struct tracer_stat
*trace
)
589 struct ftrace_profile_stat
*stat
=
590 container_of(trace
, struct ftrace_profile_stat
, stat
);
592 if (!stat
|| !stat
->start
)
595 return function_stat_next(&stat
->start
->records
[0], 0);
598 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
599 /* function graph compares on total time */
600 static int function_stat_cmp(void *p1
, void *p2
)
602 struct ftrace_profile
*a
= p1
;
603 struct ftrace_profile
*b
= p2
;
605 if (a
->time
< b
->time
)
607 if (a
->time
> b
->time
)
613 /* not function graph compares against hits */
614 static int function_stat_cmp(void *p1
, void *p2
)
616 struct ftrace_profile
*a
= p1
;
617 struct ftrace_profile
*b
= p2
;
619 if (a
->counter
< b
->counter
)
621 if (a
->counter
> b
->counter
)
628 static int function_stat_headers(struct seq_file
*m
)
630 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
631 seq_printf(m
, " Function "
634 "--- ---- --- ---\n");
636 seq_printf(m
, " Function Hit\n"
642 static int function_stat_show(struct seq_file
*m
, void *v
)
644 struct ftrace_profile
*rec
= v
;
645 char str
[KSYM_SYMBOL_LEN
];
647 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
648 static struct trace_seq s
;
649 unsigned long long avg
;
650 unsigned long long stddev
;
652 mutex_lock(&ftrace_profile_lock
);
654 /* we raced with function_profile_reset() */
655 if (unlikely(rec
->counter
== 0)) {
660 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
661 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
663 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
666 do_div(avg
, rec
->counter
);
668 /* Sample standard deviation (s^2) */
669 if (rec
->counter
<= 1)
672 stddev
= rec
->time_squared
- rec
->counter
* avg
* avg
;
674 * Divide only 1000 for ns^2 -> us^2 conversion.
675 * trace_print_graph_duration will divide 1000 again.
677 do_div(stddev
, (rec
->counter
- 1) * 1000);
681 trace_print_graph_duration(rec
->time
, &s
);
682 trace_seq_puts(&s
, " ");
683 trace_print_graph_duration(avg
, &s
);
684 trace_seq_puts(&s
, " ");
685 trace_print_graph_duration(stddev
, &s
);
686 trace_print_seq(m
, &s
);
690 mutex_unlock(&ftrace_profile_lock
);
695 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
697 struct ftrace_profile_page
*pg
;
699 pg
= stat
->pages
= stat
->start
;
702 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
707 memset(stat
->hash
, 0,
708 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
711 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
713 struct ftrace_profile_page
*pg
;
718 /* If we already allocated, do nothing */
722 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
726 #ifdef CONFIG_DYNAMIC_FTRACE
727 functions
= ftrace_update_tot_cnt
;
730 * We do not know the number of functions that exist because
731 * dynamic tracing is what counts them. With past experience
732 * we have around 20K functions. That should be more than enough.
733 * It is highly unlikely we will execute every function in
739 pg
= stat
->start
= stat
->pages
;
741 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
743 for (i
= 1; i
< pages
; i
++) {
744 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
755 unsigned long tmp
= (unsigned long)pg
;
767 static int ftrace_profile_init_cpu(int cpu
)
769 struct ftrace_profile_stat
*stat
;
772 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
775 /* If the profile is already created, simply reset it */
776 ftrace_profile_reset(stat
);
781 * We are profiling all functions, but usually only a few thousand
782 * functions are hit. We'll make a hash of 1024 items.
784 size
= FTRACE_PROFILE_HASH_SIZE
;
786 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
791 /* Preallocate the function profiling pages */
792 if (ftrace_profile_pages_init(stat
) < 0) {
801 static int ftrace_profile_init(void)
806 for_each_possible_cpu(cpu
) {
807 ret
= ftrace_profile_init_cpu(cpu
);
815 /* interrupts must be disabled */
816 static struct ftrace_profile
*
817 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
819 struct ftrace_profile
*rec
;
820 struct hlist_head
*hhd
;
823 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
824 hhd
= &stat
->hash
[key
];
826 if (hlist_empty(hhd
))
829 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
837 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
838 struct ftrace_profile
*rec
)
842 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
843 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
847 * The memory is already allocated, this simply finds a new record to use.
849 static struct ftrace_profile
*
850 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
852 struct ftrace_profile
*rec
= NULL
;
854 /* prevent recursion (from NMIs) */
855 if (atomic_inc_return(&stat
->disabled
) != 1)
859 * Try to find the function again since an NMI
860 * could have added it
862 rec
= ftrace_find_profiled_func(stat
, ip
);
866 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
867 if (!stat
->pages
->next
)
869 stat
->pages
= stat
->pages
->next
;
872 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
874 ftrace_add_profile(stat
, rec
);
877 atomic_dec(&stat
->disabled
);
883 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
884 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
886 struct ftrace_profile_stat
*stat
;
887 struct ftrace_profile
*rec
;
890 if (!ftrace_profile_enabled
)
893 local_irq_save(flags
);
895 stat
= &__get_cpu_var(ftrace_profile_stats
);
896 if (!stat
->hash
|| !ftrace_profile_enabled
)
899 rec
= ftrace_find_profiled_func(stat
, ip
);
901 rec
= ftrace_profile_alloc(stat
, ip
);
908 local_irq_restore(flags
);
911 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
912 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
914 function_profile_call(trace
->func
, 0, NULL
, NULL
);
918 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
920 struct ftrace_profile_stat
*stat
;
921 unsigned long long calltime
;
922 struct ftrace_profile
*rec
;
925 local_irq_save(flags
);
926 stat
= &__get_cpu_var(ftrace_profile_stats
);
927 if (!stat
->hash
|| !ftrace_profile_enabled
)
930 /* If the calltime was zero'd ignore it */
931 if (!trace
->calltime
)
934 calltime
= trace
->rettime
- trace
->calltime
;
936 if (!(trace_flags
& TRACE_ITER_GRAPH_TIME
)) {
939 index
= trace
->depth
;
941 /* Append this call time to the parent time to subtract */
943 current
->ret_stack
[index
- 1].subtime
+= calltime
;
945 if (current
->ret_stack
[index
].subtime
< calltime
)
946 calltime
-= current
->ret_stack
[index
].subtime
;
951 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
953 rec
->time
+= calltime
;
954 rec
->time_squared
+= calltime
* calltime
;
958 local_irq_restore(flags
);
961 static int register_ftrace_profiler(void)
963 return register_ftrace_graph(&profile_graph_return
,
964 &profile_graph_entry
);
967 static void unregister_ftrace_profiler(void)
969 unregister_ftrace_graph();
972 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
973 .func
= function_profile_call
,
974 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
975 INIT_REGEX_LOCK(ftrace_profile_ops
)
978 static int register_ftrace_profiler(void)
980 return register_ftrace_function(&ftrace_profile_ops
);
983 static void unregister_ftrace_profiler(void)
985 unregister_ftrace_function(&ftrace_profile_ops
);
987 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
990 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
991 size_t cnt
, loff_t
*ppos
)
996 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
1002 mutex_lock(&ftrace_profile_lock
);
1003 if (ftrace_profile_enabled
^ val
) {
1005 ret
= ftrace_profile_init();
1011 ret
= register_ftrace_profiler();
1016 ftrace_profile_enabled
= 1;
1018 ftrace_profile_enabled
= 0;
1020 * unregister_ftrace_profiler calls stop_machine
1021 * so this acts like an synchronize_sched.
1023 unregister_ftrace_profiler();
1027 mutex_unlock(&ftrace_profile_lock
);
1035 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
1036 size_t cnt
, loff_t
*ppos
)
1038 char buf
[64]; /* big enough to hold a number */
1041 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
1042 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
1045 static const struct file_operations ftrace_profile_fops
= {
1046 .open
= tracing_open_generic
,
1047 .read
= ftrace_profile_read
,
1048 .write
= ftrace_profile_write
,
1049 .llseek
= default_llseek
,
1052 /* used to initialize the real stat files */
1053 static struct tracer_stat function_stats __initdata
= {
1054 .name
= "functions",
1055 .stat_start
= function_stat_start
,
1056 .stat_next
= function_stat_next
,
1057 .stat_cmp
= function_stat_cmp
,
1058 .stat_headers
= function_stat_headers
,
1059 .stat_show
= function_stat_show
1062 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1064 struct ftrace_profile_stat
*stat
;
1065 struct dentry
*entry
;
1070 for_each_possible_cpu(cpu
) {
1071 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1073 /* allocate enough for function name + cpu number */
1074 name
= kmalloc(32, GFP_KERNEL
);
1077 * The files created are permanent, if something happens
1078 * we still do not free memory.
1081 "Could not allocate stat file for cpu %d\n",
1085 stat
->stat
= function_stats
;
1086 snprintf(name
, 32, "function%d", cpu
);
1087 stat
->stat
.name
= name
;
1088 ret
= register_stat_tracer(&stat
->stat
);
1091 "Could not register function stat for cpu %d\n",
1098 entry
= debugfs_create_file("function_profile_enabled", 0644,
1099 d_tracer
, NULL
, &ftrace_profile_fops
);
1101 pr_warning("Could not create debugfs "
1102 "'function_profile_enabled' entry\n");
1105 #else /* CONFIG_FUNCTION_PROFILER */
1106 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1109 #endif /* CONFIG_FUNCTION_PROFILER */
1111 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1114 ftrace_filter_lseek(struct file
*file
, loff_t offset
, int whence
)
1118 if (file
->f_mode
& FMODE_READ
)
1119 ret
= seq_lseek(file
, offset
, whence
);
1121 file
->f_pos
= ret
= 1;
1126 #ifdef CONFIG_DYNAMIC_FTRACE
1128 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1129 # error Dynamic ftrace depends on MCOUNT_RECORD
1132 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1134 struct ftrace_func_probe
{
1135 struct hlist_node node
;
1136 struct ftrace_probe_ops
*ops
;
1137 unsigned long flags
;
1140 struct list_head free_list
;
1143 struct ftrace_func_entry
{
1144 struct hlist_node hlist
;
1148 struct ftrace_hash
{
1149 unsigned long size_bits
;
1150 struct hlist_head
*buckets
;
1151 unsigned long count
;
1152 struct rcu_head rcu
;
1156 * We make these constant because no one should touch them,
1157 * but they are used as the default "empty hash", to avoid allocating
1158 * it all the time. These are in a read only section such that if
1159 * anyone does try to modify it, it will cause an exception.
1161 static const struct hlist_head empty_buckets
[1];
1162 static const struct ftrace_hash empty_hash
= {
1163 .buckets
= (struct hlist_head
*)empty_buckets
,
1165 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1167 static struct ftrace_ops global_ops
= {
1168 .func
= ftrace_stub
,
1169 .notrace_hash
= EMPTY_HASH
,
1170 .filter_hash
= EMPTY_HASH
,
1171 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
1172 INIT_REGEX_LOCK(global_ops
)
1175 struct ftrace_page
{
1176 struct ftrace_page
*next
;
1177 struct dyn_ftrace
*records
;
1182 static struct ftrace_page
*ftrace_new_pgs
;
1184 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1185 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1187 /* estimate from running different kernels */
1188 #define NR_TO_INIT 10000
1190 static struct ftrace_page
*ftrace_pages_start
;
1191 static struct ftrace_page
*ftrace_pages
;
1193 static bool ftrace_hash_empty(struct ftrace_hash
*hash
)
1195 return !hash
|| !hash
->count
;
1198 static struct ftrace_func_entry
*
1199 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1202 struct ftrace_func_entry
*entry
;
1203 struct hlist_head
*hhd
;
1205 if (ftrace_hash_empty(hash
))
1208 if (hash
->size_bits
> 0)
1209 key
= hash_long(ip
, hash
->size_bits
);
1213 hhd
= &hash
->buckets
[key
];
1215 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1216 if (entry
->ip
== ip
)
1222 static void __add_hash_entry(struct ftrace_hash
*hash
,
1223 struct ftrace_func_entry
*entry
)
1225 struct hlist_head
*hhd
;
1228 if (hash
->size_bits
)
1229 key
= hash_long(entry
->ip
, hash
->size_bits
);
1233 hhd
= &hash
->buckets
[key
];
1234 hlist_add_head(&entry
->hlist
, hhd
);
1238 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1240 struct ftrace_func_entry
*entry
;
1242 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1247 __add_hash_entry(hash
, entry
);
1253 free_hash_entry(struct ftrace_hash
*hash
,
1254 struct ftrace_func_entry
*entry
)
1256 hlist_del(&entry
->hlist
);
1262 remove_hash_entry(struct ftrace_hash
*hash
,
1263 struct ftrace_func_entry
*entry
)
1265 hlist_del(&entry
->hlist
);
1269 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1271 struct hlist_head
*hhd
;
1272 struct hlist_node
*tn
;
1273 struct ftrace_func_entry
*entry
;
1274 int size
= 1 << hash
->size_bits
;
1280 for (i
= 0; i
< size
; i
++) {
1281 hhd
= &hash
->buckets
[i
];
1282 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1283 free_hash_entry(hash
, entry
);
1285 FTRACE_WARN_ON(hash
->count
);
1288 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1290 if (!hash
|| hash
== EMPTY_HASH
)
1292 ftrace_hash_clear(hash
);
1293 kfree(hash
->buckets
);
1297 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1299 struct ftrace_hash
*hash
;
1301 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1302 free_ftrace_hash(hash
);
1305 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1307 if (!hash
|| hash
== EMPTY_HASH
)
1309 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1312 void ftrace_free_filter(struct ftrace_ops
*ops
)
1314 ftrace_ops_init(ops
);
1315 free_ftrace_hash(ops
->filter_hash
);
1316 free_ftrace_hash(ops
->notrace_hash
);
1319 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1321 struct ftrace_hash
*hash
;
1324 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1328 size
= 1 << size_bits
;
1329 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1331 if (!hash
->buckets
) {
1336 hash
->size_bits
= size_bits
;
1341 static struct ftrace_hash
*
1342 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1344 struct ftrace_func_entry
*entry
;
1345 struct ftrace_hash
*new_hash
;
1350 new_hash
= alloc_ftrace_hash(size_bits
);
1355 if (ftrace_hash_empty(hash
))
1358 size
= 1 << hash
->size_bits
;
1359 for (i
= 0; i
< size
; i
++) {
1360 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1361 ret
= add_hash_entry(new_hash
, entry
->ip
);
1367 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1372 free_ftrace_hash(new_hash
);
1377 ftrace_hash_rec_disable(struct ftrace_ops
*ops
, int filter_hash
);
1379 ftrace_hash_rec_enable(struct ftrace_ops
*ops
, int filter_hash
);
1382 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1383 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1385 struct ftrace_func_entry
*entry
;
1386 struct hlist_node
*tn
;
1387 struct hlist_head
*hhd
;
1388 struct ftrace_hash
*old_hash
;
1389 struct ftrace_hash
*new_hash
;
1390 int size
= src
->count
;
1396 * Remove the current set, update the hash and add
1399 ftrace_hash_rec_disable(ops
, enable
);
1402 * If the new source is empty, just free dst and assign it
1406 free_ftrace_hash_rcu(*dst
);
1407 rcu_assign_pointer(*dst
, EMPTY_HASH
);
1408 /* still need to update the function records */
1414 * Make the hash size about 1/2 the # found
1416 for (size
/= 2; size
; size
>>= 1)
1419 /* Don't allocate too much */
1420 if (bits
> FTRACE_HASH_MAX_BITS
)
1421 bits
= FTRACE_HASH_MAX_BITS
;
1424 new_hash
= alloc_ftrace_hash(bits
);
1428 size
= 1 << src
->size_bits
;
1429 for (i
= 0; i
< size
; i
++) {
1430 hhd
= &src
->buckets
[i
];
1431 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1432 remove_hash_entry(src
, entry
);
1433 __add_hash_entry(new_hash
, entry
);
1438 rcu_assign_pointer(*dst
, new_hash
);
1439 free_ftrace_hash_rcu(old_hash
);
1444 * Enable regardless of ret:
1445 * On success, we enable the new hash.
1446 * On failure, we re-enable the original hash.
1448 ftrace_hash_rec_enable(ops
, enable
);
1454 * Test the hashes for this ops to see if we want to call
1455 * the ops->func or not.
1457 * It's a match if the ip is in the ops->filter_hash or
1458 * the filter_hash does not exist or is empty,
1460 * the ip is not in the ops->notrace_hash.
1462 * This needs to be called with preemption disabled as
1463 * the hashes are freed with call_rcu_sched().
1466 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1468 struct ftrace_hash
*filter_hash
;
1469 struct ftrace_hash
*notrace_hash
;
1472 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1474 * There's a small race when adding ops that the ftrace handler
1475 * that wants regs, may be called without them. We can not
1476 * allow that handler to be called if regs is NULL.
1478 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1482 filter_hash
= rcu_dereference_raw_notrace(ops
->filter_hash
);
1483 notrace_hash
= rcu_dereference_raw_notrace(ops
->notrace_hash
);
1485 if ((ftrace_hash_empty(filter_hash
) ||
1486 ftrace_lookup_ip(filter_hash
, ip
)) &&
1487 (ftrace_hash_empty(notrace_hash
) ||
1488 !ftrace_lookup_ip(notrace_hash
, ip
)))
1497 * This is a double for. Do not use 'break' to break out of the loop,
1498 * you must use a goto.
1500 #define do_for_each_ftrace_rec(pg, rec) \
1501 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1503 for (_____i = 0; _____i < pg->index; _____i++) { \
1504 rec = &pg->records[_____i];
1506 #define while_for_each_ftrace_rec() \
1511 static int ftrace_cmp_recs(const void *a
, const void *b
)
1513 const struct dyn_ftrace
*key
= a
;
1514 const struct dyn_ftrace
*rec
= b
;
1516 if (key
->flags
< rec
->ip
)
1518 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1523 static unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1525 struct ftrace_page
*pg
;
1526 struct dyn_ftrace
*rec
;
1527 struct dyn_ftrace key
;
1530 key
.flags
= end
; /* overload flags, as it is unsigned long */
1532 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1533 if (end
< pg
->records
[0].ip
||
1534 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1536 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1537 sizeof(struct dyn_ftrace
),
1547 * ftrace_location - return true if the ip giving is a traced location
1548 * @ip: the instruction pointer to check
1550 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1551 * That is, the instruction that is either a NOP or call to
1552 * the function tracer. It checks the ftrace internal tables to
1553 * determine if the address belongs or not.
1555 unsigned long ftrace_location(unsigned long ip
)
1557 return ftrace_location_range(ip
, ip
);
1561 * ftrace_text_reserved - return true if range contains an ftrace location
1562 * @start: start of range to search
1563 * @end: end of range to search (inclusive). @end points to the last byte to check.
1565 * Returns 1 if @start and @end contains a ftrace location.
1566 * That is, the instruction that is either a NOP or call to
1567 * the function tracer. It checks the ftrace internal tables to
1568 * determine if the address belongs or not.
1570 int ftrace_text_reserved(void *start
, void *end
)
1574 ret
= ftrace_location_range((unsigned long)start
,
1575 (unsigned long)end
);
1580 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1584 struct ftrace_hash
*hash
;
1585 struct ftrace_hash
*other_hash
;
1586 struct ftrace_page
*pg
;
1587 struct dyn_ftrace
*rec
;
1591 /* Only update if the ops has been registered */
1592 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1596 * In the filter_hash case:
1597 * If the count is zero, we update all records.
1598 * Otherwise we just update the items in the hash.
1600 * In the notrace_hash case:
1601 * We enable the update in the hash.
1602 * As disabling notrace means enabling the tracing,
1603 * and enabling notrace means disabling, the inc variable
1607 hash
= ops
->filter_hash
;
1608 other_hash
= ops
->notrace_hash
;
1609 if (ftrace_hash_empty(hash
))
1613 hash
= ops
->notrace_hash
;
1614 other_hash
= ops
->filter_hash
;
1616 * If the notrace hash has no items,
1617 * then there's nothing to do.
1619 if (ftrace_hash_empty(hash
))
1623 do_for_each_ftrace_rec(pg
, rec
) {
1624 int in_other_hash
= 0;
1630 * Only the filter_hash affects all records.
1631 * Update if the record is not in the notrace hash.
1633 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1636 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1637 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1642 if (filter_hash
&& in_hash
&& !in_other_hash
)
1644 else if (!filter_hash
&& in_hash
&&
1645 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1653 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == FTRACE_REF_MAX
))
1656 * If any ops wants regs saved for this function
1657 * then all ops will get saved regs.
1659 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1660 rec
->flags
|= FTRACE_FL_REGS
;
1662 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == 0))
1667 /* Shortcut, if we handled all records, we are done. */
1668 if (!all
&& count
== hash
->count
)
1670 } while_for_each_ftrace_rec();
1673 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1676 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1679 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1682 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1685 static void print_ip_ins(const char *fmt
, unsigned char *p
)
1689 printk(KERN_CONT
"%s", fmt
);
1691 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1692 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1696 * ftrace_bug - report and shutdown function tracer
1697 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1698 * @ip: The address that failed
1700 * The arch code that enables or disables the function tracing
1701 * can call ftrace_bug() when it has detected a problem in
1702 * modifying the code. @failed should be one of either:
1703 * EFAULT - if the problem happens on reading the @ip address
1704 * EINVAL - if what is read at @ip is not what was expected
1705 * EPERM - if the problem happens on writting to the @ip address
1707 void ftrace_bug(int failed
, unsigned long ip
)
1711 FTRACE_WARN_ON_ONCE(1);
1712 pr_info("ftrace faulted on modifying ");
1716 FTRACE_WARN_ON_ONCE(1);
1717 pr_info("ftrace failed to modify ");
1719 print_ip_ins(" actual: ", (unsigned char *)ip
);
1720 printk(KERN_CONT
"\n");
1723 FTRACE_WARN_ON_ONCE(1);
1724 pr_info("ftrace faulted on writing ");
1728 FTRACE_WARN_ON_ONCE(1);
1729 pr_info("ftrace faulted on unknown error ");
1734 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
1736 unsigned long flag
= 0UL;
1739 * If we are updating calls:
1741 * If the record has a ref count, then we need to enable it
1742 * because someone is using it.
1744 * Otherwise we make sure its disabled.
1746 * If we are disabling calls, then disable all records that
1749 if (enable
&& (rec
->flags
& ~FTRACE_FL_MASK
))
1750 flag
= FTRACE_FL_ENABLED
;
1753 * If enabling and the REGS flag does not match the REGS_EN, then
1754 * do not ignore this record. Set flags to fail the compare against
1758 (!(rec
->flags
& FTRACE_FL_REGS
) != !(rec
->flags
& FTRACE_FL_REGS_EN
)))
1759 flag
|= FTRACE_FL_REGS
;
1761 /* If the state of this record hasn't changed, then do nothing */
1762 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
1763 return FTRACE_UPDATE_IGNORE
;
1766 /* Save off if rec is being enabled (for return value) */
1767 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
1770 rec
->flags
|= FTRACE_FL_ENABLED
;
1771 if (flag
& FTRACE_FL_REGS
) {
1772 if (rec
->flags
& FTRACE_FL_REGS
)
1773 rec
->flags
|= FTRACE_FL_REGS_EN
;
1775 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
1780 * If this record is being updated from a nop, then
1781 * return UPDATE_MAKE_CALL.
1782 * Otherwise, if the EN flag is set, then return
1783 * UPDATE_MODIFY_CALL_REGS to tell the caller to convert
1784 * from the non-save regs, to a save regs function.
1786 * return UPDATE_MODIFY_CALL to tell the caller to convert
1787 * from the save regs, to a non-save regs function.
1789 if (flag
& FTRACE_FL_ENABLED
)
1790 return FTRACE_UPDATE_MAKE_CALL
;
1791 else if (rec
->flags
& FTRACE_FL_REGS_EN
)
1792 return FTRACE_UPDATE_MODIFY_CALL_REGS
;
1794 return FTRACE_UPDATE_MODIFY_CALL
;
1798 /* If there's no more users, clear all flags */
1799 if (!(rec
->flags
& ~FTRACE_FL_MASK
))
1802 /* Just disable the record (keep REGS state) */
1803 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1806 return FTRACE_UPDATE_MAKE_NOP
;
1810 * ftrace_update_record, set a record that now is tracing or not
1811 * @rec: the record to update
1812 * @enable: set to 1 if the record is tracing, zero to force disable
1814 * The records that represent all functions that can be traced need
1815 * to be updated when tracing has been enabled.
1817 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
1819 return ftrace_check_record(rec
, enable
, 1);
1823 * ftrace_test_record, check if the record has been enabled or not
1824 * @rec: the record to test
1825 * @enable: set to 1 to check if enabled, 0 if it is disabled
1827 * The arch code may need to test if a record is already set to
1828 * tracing to determine how to modify the function code that it
1831 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
1833 return ftrace_check_record(rec
, enable
, 0);
1837 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
1839 unsigned long ftrace_old_addr
;
1840 unsigned long ftrace_addr
;
1843 ret
= ftrace_update_record(rec
, enable
);
1845 if (rec
->flags
& FTRACE_FL_REGS
)
1846 ftrace_addr
= (unsigned long)FTRACE_REGS_ADDR
;
1848 ftrace_addr
= (unsigned long)FTRACE_ADDR
;
1851 case FTRACE_UPDATE_IGNORE
:
1854 case FTRACE_UPDATE_MAKE_CALL
:
1855 return ftrace_make_call(rec
, ftrace_addr
);
1857 case FTRACE_UPDATE_MAKE_NOP
:
1858 return ftrace_make_nop(NULL
, rec
, ftrace_addr
);
1860 case FTRACE_UPDATE_MODIFY_CALL_REGS
:
1861 case FTRACE_UPDATE_MODIFY_CALL
:
1862 if (rec
->flags
& FTRACE_FL_REGS
)
1863 ftrace_old_addr
= (unsigned long)FTRACE_ADDR
;
1865 ftrace_old_addr
= (unsigned long)FTRACE_REGS_ADDR
;
1867 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
1870 return -1; /* unknow ftrace bug */
1873 void __weak
ftrace_replace_code(int enable
)
1875 struct dyn_ftrace
*rec
;
1876 struct ftrace_page
*pg
;
1879 if (unlikely(ftrace_disabled
))
1882 do_for_each_ftrace_rec(pg
, rec
) {
1883 failed
= __ftrace_replace_code(rec
, enable
);
1885 ftrace_bug(failed
, rec
->ip
);
1886 /* Stop processing */
1889 } while_for_each_ftrace_rec();
1892 struct ftrace_rec_iter
{
1893 struct ftrace_page
*pg
;
1898 * ftrace_rec_iter_start, start up iterating over traced functions
1900 * Returns an iterator handle that is used to iterate over all
1901 * the records that represent address locations where functions
1904 * May return NULL if no records are available.
1906 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
1909 * We only use a single iterator.
1910 * Protected by the ftrace_lock mutex.
1912 static struct ftrace_rec_iter ftrace_rec_iter
;
1913 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
1915 iter
->pg
= ftrace_pages_start
;
1918 /* Could have empty pages */
1919 while (iter
->pg
&& !iter
->pg
->index
)
1920 iter
->pg
= iter
->pg
->next
;
1929 * ftrace_rec_iter_next, get the next record to process.
1930 * @iter: The handle to the iterator.
1932 * Returns the next iterator after the given iterator @iter.
1934 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
1938 if (iter
->index
>= iter
->pg
->index
) {
1939 iter
->pg
= iter
->pg
->next
;
1942 /* Could have empty pages */
1943 while (iter
->pg
&& !iter
->pg
->index
)
1944 iter
->pg
= iter
->pg
->next
;
1954 * ftrace_rec_iter_record, get the record at the iterator location
1955 * @iter: The current iterator location
1957 * Returns the record that the current @iter is at.
1959 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
1961 return &iter
->pg
->records
[iter
->index
];
1965 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
1972 if (unlikely(ftrace_disabled
))
1975 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
1977 ftrace_bug(ret
, ip
);
1984 * archs can override this function if they must do something
1985 * before the modifying code is performed.
1987 int __weak
ftrace_arch_code_modify_prepare(void)
1993 * archs can override this function if they must do something
1994 * after the modifying code is performed.
1996 int __weak
ftrace_arch_code_modify_post_process(void)
2001 void ftrace_modify_all_code(int command
)
2003 if (command
& FTRACE_UPDATE_CALLS
)
2004 ftrace_replace_code(1);
2005 else if (command
& FTRACE_DISABLE_CALLS
)
2006 ftrace_replace_code(0);
2008 if (command
& FTRACE_UPDATE_TRACE_FUNC
) {
2009 function_trace_op
= set_function_trace_op
;
2011 /* If irqs are disabled, we are in stop machine */
2012 if (!irqs_disabled())
2013 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2014 ftrace_update_ftrace_func(ftrace_trace_function
);
2017 if (command
& FTRACE_START_FUNC_RET
)
2018 ftrace_enable_ftrace_graph_caller();
2019 else if (command
& FTRACE_STOP_FUNC_RET
)
2020 ftrace_disable_ftrace_graph_caller();
2023 static int __ftrace_modify_code(void *data
)
2025 int *command
= data
;
2027 ftrace_modify_all_code(*command
);
2033 * ftrace_run_stop_machine, go back to the stop machine method
2034 * @command: The command to tell ftrace what to do
2036 * If an arch needs to fall back to the stop machine method, the
2037 * it can call this function.
2039 void ftrace_run_stop_machine(int command
)
2041 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2045 * arch_ftrace_update_code, modify the code to trace or not trace
2046 * @command: The command that needs to be done
2048 * Archs can override this function if it does not need to
2049 * run stop_machine() to modify code.
2051 void __weak
arch_ftrace_update_code(int command
)
2053 ftrace_run_stop_machine(command
);
2056 static void ftrace_run_update_code(int command
)
2060 ret
= ftrace_arch_code_modify_prepare();
2061 FTRACE_WARN_ON(ret
);
2065 * Do not call function tracer while we update the code.
2066 * We are in stop machine.
2068 function_trace_stop
++;
2071 * By default we use stop_machine() to modify the code.
2072 * But archs can do what ever they want as long as it
2073 * is safe. The stop_machine() is the safest, but also
2074 * produces the most overhead.
2076 arch_ftrace_update_code(command
);
2078 function_trace_stop
--;
2080 ret
= ftrace_arch_code_modify_post_process();
2081 FTRACE_WARN_ON(ret
);
2084 static ftrace_func_t saved_ftrace_func
;
2085 static int ftrace_start_up
;
2086 static int global_start_up
;
2088 static void ftrace_startup_enable(int command
)
2090 if (saved_ftrace_func
!= ftrace_trace_function
) {
2091 saved_ftrace_func
= ftrace_trace_function
;
2092 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2095 if (!command
|| !ftrace_enabled
)
2098 ftrace_run_update_code(command
);
2101 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2103 bool hash_enable
= true;
2106 if (unlikely(ftrace_disabled
))
2109 ret
= __register_ftrace_function(ops
);
2114 command
|= FTRACE_UPDATE_CALLS
;
2116 /* ops marked global share the filter hashes */
2117 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
2119 /* Don't update hash if global is already set */
2120 if (global_start_up
)
2121 hash_enable
= false;
2125 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
2127 ftrace_hash_rec_enable(ops
, 1);
2129 ftrace_startup_enable(command
);
2134 static int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2136 bool hash_disable
= true;
2139 if (unlikely(ftrace_disabled
))
2142 ret
= __unregister_ftrace_function(ops
);
2148 * Just warn in case of unbalance, no need to kill ftrace, it's not
2149 * critical but the ftrace_call callers may be never nopped again after
2150 * further ftrace uses.
2152 WARN_ON_ONCE(ftrace_start_up
< 0);
2154 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
2157 WARN_ON_ONCE(global_start_up
< 0);
2158 /* Don't update hash if global still has users */
2159 if (global_start_up
) {
2160 WARN_ON_ONCE(!ftrace_start_up
);
2161 hash_disable
= false;
2166 ftrace_hash_rec_disable(ops
, 1);
2168 if (ops
!= &global_ops
|| !global_start_up
)
2169 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2171 command
|= FTRACE_UPDATE_CALLS
;
2173 if (saved_ftrace_func
!= ftrace_trace_function
) {
2174 saved_ftrace_func
= ftrace_trace_function
;
2175 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2178 if (!command
|| !ftrace_enabled
) {
2180 * If these are control ops, they still need their
2181 * per_cpu field freed. Since, function tracing is
2182 * not currently active, we can just free them
2183 * without synchronizing all CPUs.
2185 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
)
2186 control_ops_free(ops
);
2190 ftrace_run_update_code(command
);
2193 * Dynamic ops may be freed, we must make sure that all
2194 * callers are done before leaving this function.
2195 * The same goes for freeing the per_cpu data of the control
2198 * Again, normal synchronize_sched() is not good enough.
2199 * We need to do a hard force of sched synchronization.
2200 * This is because we use preempt_disable() to do RCU, but
2201 * the function tracers can be called where RCU is not watching
2202 * (like before user_exit()). We can not rely on the RCU
2203 * infrastructure to do the synchronization, thus we must do it
2206 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_CONTROL
)) {
2207 schedule_on_each_cpu(ftrace_sync
);
2209 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
)
2210 control_ops_free(ops
);
2216 static void ftrace_startup_sysctl(void)
2218 if (unlikely(ftrace_disabled
))
2221 /* Force update next time */
2222 saved_ftrace_func
= NULL
;
2223 /* ftrace_start_up is true if we want ftrace running */
2224 if (ftrace_start_up
)
2225 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
2228 static void ftrace_shutdown_sysctl(void)
2230 if (unlikely(ftrace_disabled
))
2233 /* ftrace_start_up is true if ftrace is running */
2234 if (ftrace_start_up
)
2235 ftrace_run_update_code(FTRACE_DISABLE_CALLS
);
2238 static cycle_t ftrace_update_time
;
2239 static unsigned long ftrace_update_cnt
;
2240 unsigned long ftrace_update_tot_cnt
;
2242 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2245 * Filter_hash being empty will default to trace module.
2246 * But notrace hash requires a test of individual module functions.
2248 return ftrace_hash_empty(ops
->filter_hash
) &&
2249 ftrace_hash_empty(ops
->notrace_hash
);
2253 * Check if the current ops references the record.
2255 * If the ops traces all functions, then it was already accounted for.
2256 * If the ops does not trace the current record function, skip it.
2257 * If the ops ignores the function via notrace filter, skip it.
2260 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2262 /* If ops isn't enabled, ignore it */
2263 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2266 /* If ops traces all mods, we already accounted for it */
2267 if (ops_traces_mod(ops
))
2270 /* The function must be in the filter */
2271 if (!ftrace_hash_empty(ops
->filter_hash
) &&
2272 !ftrace_lookup_ip(ops
->filter_hash
, rec
->ip
))
2275 /* If in notrace hash, we ignore it too */
2276 if (ftrace_lookup_ip(ops
->notrace_hash
, rec
->ip
))
2282 static int referenced_filters(struct dyn_ftrace
*rec
)
2284 struct ftrace_ops
*ops
;
2287 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2288 if (ops_references_rec(ops
, rec
))
2295 static int ftrace_update_code(struct module
*mod
)
2297 struct ftrace_page
*pg
;
2298 struct dyn_ftrace
*p
;
2299 cycle_t start
, stop
;
2300 unsigned long ref
= 0;
2305 * When adding a module, we need to check if tracers are
2306 * currently enabled and if they are set to trace all functions.
2307 * If they are, we need to enable the module functions as well
2308 * as update the reference counts for those function records.
2311 struct ftrace_ops
*ops
;
2313 for (ops
= ftrace_ops_list
;
2314 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2315 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
2316 if (ops_traces_mod(ops
))
2324 start
= ftrace_now(raw_smp_processor_id());
2325 ftrace_update_cnt
= 0;
2327 for (pg
= ftrace_new_pgs
; pg
; pg
= pg
->next
) {
2329 for (i
= 0; i
< pg
->index
; i
++) {
2332 /* If something went wrong, bail without enabling anything */
2333 if (unlikely(ftrace_disabled
))
2336 p
= &pg
->records
[i
];
2338 cnt
+= referenced_filters(p
);
2342 * Do the initial record conversion from mcount jump
2343 * to the NOP instructions.
2345 if (!ftrace_code_disable(mod
, p
))
2348 ftrace_update_cnt
++;
2351 * If the tracing is enabled, go ahead and enable the record.
2353 * The reason not to enable the record immediatelly is the
2354 * inherent check of ftrace_make_nop/ftrace_make_call for
2355 * correct previous instructions. Making first the NOP
2356 * conversion puts the module to the correct state, thus
2357 * passing the ftrace_make_call check.
2359 if (ftrace_start_up
&& cnt
) {
2360 int failed
= __ftrace_replace_code(p
, 1);
2362 ftrace_bug(failed
, p
->ip
);
2367 ftrace_new_pgs
= NULL
;
2369 stop
= ftrace_now(raw_smp_processor_id());
2370 ftrace_update_time
= stop
- start
;
2371 ftrace_update_tot_cnt
+= ftrace_update_cnt
;
2376 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2381 if (WARN_ON(!count
))
2384 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2387 * We want to fill as much as possible. No more than a page
2390 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2394 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2397 /* if we can't allocate this size, try something smaller */
2404 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2413 static struct ftrace_page
*
2414 ftrace_allocate_pages(unsigned long num_to_init
)
2416 struct ftrace_page
*start_pg
;
2417 struct ftrace_page
*pg
;
2424 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2429 * Try to allocate as much as possible in one continues
2430 * location that fills in all of the space. We want to
2431 * waste as little space as possible.
2434 cnt
= ftrace_allocate_records(pg
, num_to_init
);
2442 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2453 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
2454 free_pages((unsigned long)pg
->records
, order
);
2455 start_pg
= pg
->next
;
2459 pr_info("ftrace: FAILED to allocate memory for functions\n");
2463 static int __init
ftrace_dyn_table_alloc(unsigned long num_to_init
)
2468 pr_info("ftrace: No functions to be traced?\n");
2472 cnt
= num_to_init
/ ENTRIES_PER_PAGE
;
2473 pr_info("ftrace: allocating %ld entries in %d pages\n",
2474 num_to_init
, cnt
+ 1);
2479 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2481 struct ftrace_iterator
{
2484 struct ftrace_page
*pg
;
2485 struct dyn_ftrace
*func
;
2486 struct ftrace_func_probe
*probe
;
2487 struct trace_parser parser
;
2488 struct ftrace_hash
*hash
;
2489 struct ftrace_ops
*ops
;
2496 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
2498 struct ftrace_iterator
*iter
= m
->private;
2499 struct hlist_node
*hnd
= NULL
;
2500 struct hlist_head
*hhd
;
2506 hnd
= &iter
->probe
->node
;
2508 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
2511 hhd
= &ftrace_func_hash
[iter
->hidx
];
2513 if (hlist_empty(hhd
)) {
2529 if (WARN_ON_ONCE(!hnd
))
2532 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
2537 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
2539 struct ftrace_iterator
*iter
= m
->private;
2543 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
2546 if (iter
->func_pos
> *pos
)
2550 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
2551 p
= t_hash_next(m
, &l
);
2558 /* Only set this if we have an item */
2559 iter
->flags
|= FTRACE_ITER_HASH
;
2565 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
2567 struct ftrace_func_probe
*rec
;
2570 if (WARN_ON_ONCE(!rec
))
2573 if (rec
->ops
->print
)
2574 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
2576 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
2579 seq_printf(m
, ":%p", rec
->data
);
2586 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2588 struct ftrace_iterator
*iter
= m
->private;
2589 struct ftrace_ops
*ops
= iter
->ops
;
2590 struct dyn_ftrace
*rec
= NULL
;
2592 if (unlikely(ftrace_disabled
))
2595 if (iter
->flags
& FTRACE_ITER_HASH
)
2596 return t_hash_next(m
, pos
);
2599 iter
->pos
= iter
->func_pos
= *pos
;
2601 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
2602 return t_hash_start(m
, pos
);
2605 if (iter
->idx
>= iter
->pg
->index
) {
2606 if (iter
->pg
->next
) {
2607 iter
->pg
= iter
->pg
->next
;
2612 rec
= &iter
->pg
->records
[iter
->idx
++];
2613 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
2614 !(ftrace_lookup_ip(ops
->filter_hash
, rec
->ip
))) ||
2616 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
2617 !ftrace_lookup_ip(ops
->notrace_hash
, rec
->ip
)) ||
2619 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
2620 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
2628 return t_hash_start(m
, pos
);
2635 static void reset_iter_read(struct ftrace_iterator
*iter
)
2639 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
2642 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2644 struct ftrace_iterator
*iter
= m
->private;
2645 struct ftrace_ops
*ops
= iter
->ops
;
2649 mutex_lock(&ftrace_lock
);
2651 if (unlikely(ftrace_disabled
))
2655 * If an lseek was done, then reset and start from beginning.
2657 if (*pos
< iter
->pos
)
2658 reset_iter_read(iter
);
2661 * For set_ftrace_filter reading, if we have the filter
2662 * off, we can short cut and just print out that all
2663 * functions are enabled.
2665 if (iter
->flags
& FTRACE_ITER_FILTER
&&
2666 ftrace_hash_empty(ops
->filter_hash
)) {
2668 return t_hash_start(m
, pos
);
2669 iter
->flags
|= FTRACE_ITER_PRINTALL
;
2670 /* reset in case of seek/pread */
2671 iter
->flags
&= ~FTRACE_ITER_HASH
;
2675 if (iter
->flags
& FTRACE_ITER_HASH
)
2676 return t_hash_start(m
, pos
);
2679 * Unfortunately, we need to restart at ftrace_pages_start
2680 * every time we let go of the ftrace_mutex. This is because
2681 * those pointers can change without the lock.
2683 iter
->pg
= ftrace_pages_start
;
2685 for (l
= 0; l
<= *pos
; ) {
2686 p
= t_next(m
, p
, &l
);
2692 return t_hash_start(m
, pos
);
2697 static void t_stop(struct seq_file
*m
, void *p
)
2699 mutex_unlock(&ftrace_lock
);
2702 static int t_show(struct seq_file
*m
, void *v
)
2704 struct ftrace_iterator
*iter
= m
->private;
2705 struct dyn_ftrace
*rec
;
2707 if (iter
->flags
& FTRACE_ITER_HASH
)
2708 return t_hash_show(m
, iter
);
2710 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
2711 seq_printf(m
, "#### all functions enabled ####\n");
2720 seq_printf(m
, "%ps", (void *)rec
->ip
);
2721 if (iter
->flags
& FTRACE_ITER_ENABLED
)
2722 seq_printf(m
, " (%ld)%s",
2723 rec
->flags
& ~FTRACE_FL_MASK
,
2724 rec
->flags
& FTRACE_FL_REGS
? " R" : "");
2725 seq_printf(m
, "\n");
2730 static const struct seq_operations show_ftrace_seq_ops
= {
2738 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
2740 struct ftrace_iterator
*iter
;
2742 if (unlikely(ftrace_disabled
))
2745 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2747 iter
->pg
= ftrace_pages_start
;
2748 iter
->ops
= &global_ops
;
2751 return iter
? 0 : -ENOMEM
;
2755 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
2757 struct ftrace_iterator
*iter
;
2759 if (unlikely(ftrace_disabled
))
2762 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2764 iter
->pg
= ftrace_pages_start
;
2765 iter
->flags
= FTRACE_ITER_ENABLED
;
2766 iter
->ops
= &global_ops
;
2769 return iter
? 0 : -ENOMEM
;
2772 static void ftrace_filter_reset(struct ftrace_hash
*hash
)
2774 mutex_lock(&ftrace_lock
);
2775 ftrace_hash_clear(hash
);
2776 mutex_unlock(&ftrace_lock
);
2780 * ftrace_regex_open - initialize function tracer filter files
2781 * @ops: The ftrace_ops that hold the hash filters
2782 * @flag: The type of filter to process
2783 * @inode: The inode, usually passed in to your open routine
2784 * @file: The file, usually passed in to your open routine
2786 * ftrace_regex_open() initializes the filter files for the
2787 * @ops. Depending on @flag it may process the filter hash or
2788 * the notrace hash of @ops. With this called from the open
2789 * routine, you can use ftrace_filter_write() for the write
2790 * routine if @flag has FTRACE_ITER_FILTER set, or
2791 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2792 * ftrace_filter_lseek() should be used as the lseek routine, and
2793 * release must call ftrace_regex_release().
2796 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
2797 struct inode
*inode
, struct file
*file
)
2799 struct ftrace_iterator
*iter
;
2800 struct ftrace_hash
*hash
;
2803 ftrace_ops_init(ops
);
2805 if (unlikely(ftrace_disabled
))
2808 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2812 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
2820 mutex_lock(&ops
->regex_lock
);
2822 if (flag
& FTRACE_ITER_NOTRACE
)
2823 hash
= ops
->notrace_hash
;
2825 hash
= ops
->filter_hash
;
2827 if (file
->f_mode
& FMODE_WRITE
) {
2828 iter
->hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, hash
);
2830 trace_parser_put(&iter
->parser
);
2837 if ((file
->f_mode
& FMODE_WRITE
) &&
2838 (file
->f_flags
& O_TRUNC
))
2839 ftrace_filter_reset(iter
->hash
);
2841 if (file
->f_mode
& FMODE_READ
) {
2842 iter
->pg
= ftrace_pages_start
;
2844 ret
= seq_open(file
, &show_ftrace_seq_ops
);
2846 struct seq_file
*m
= file
->private_data
;
2850 free_ftrace_hash(iter
->hash
);
2851 trace_parser_put(&iter
->parser
);
2855 file
->private_data
= iter
;
2858 mutex_unlock(&ops
->regex_lock
);
2864 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
2866 return ftrace_regex_open(&global_ops
,
2867 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
2872 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
2874 return ftrace_regex_open(&global_ops
, FTRACE_ITER_NOTRACE
,
2878 static int ftrace_match(char *str
, char *regex
, int len
, int type
)
2885 if (strcmp(str
, regex
) == 0)
2888 case MATCH_FRONT_ONLY
:
2889 if (strncmp(str
, regex
, len
) == 0)
2892 case MATCH_MIDDLE_ONLY
:
2893 if (strstr(str
, regex
))
2896 case MATCH_END_ONLY
:
2898 if (slen
>= len
&& memcmp(str
+ slen
- len
, regex
, len
) == 0)
2907 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int not)
2909 struct ftrace_func_entry
*entry
;
2912 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
2914 /* Do nothing if it doesn't exist */
2918 free_hash_entry(hash
, entry
);
2920 /* Do nothing if it exists */
2924 ret
= add_hash_entry(hash
, rec
->ip
);
2930 ftrace_match_record(struct dyn_ftrace
*rec
, char *mod
,
2931 char *regex
, int len
, int type
)
2933 char str
[KSYM_SYMBOL_LEN
];
2936 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
2939 /* module lookup requires matching the module */
2940 if (!modname
|| strcmp(modname
, mod
))
2943 /* blank search means to match all funcs in the mod */
2948 return ftrace_match(str
, regex
, len
, type
);
2952 match_records(struct ftrace_hash
*hash
, char *buff
,
2953 int len
, char *mod
, int not)
2955 unsigned search_len
= 0;
2956 struct ftrace_page
*pg
;
2957 struct dyn_ftrace
*rec
;
2958 int type
= MATCH_FULL
;
2959 char *search
= buff
;
2964 type
= filter_parse_regex(buff
, len
, &search
, ¬);
2965 search_len
= strlen(search
);
2968 mutex_lock(&ftrace_lock
);
2970 if (unlikely(ftrace_disabled
))
2973 do_for_each_ftrace_rec(pg
, rec
) {
2974 if (ftrace_match_record(rec
, mod
, search
, search_len
, type
)) {
2975 ret
= enter_record(hash
, rec
, not);
2982 } while_for_each_ftrace_rec();
2984 mutex_unlock(&ftrace_lock
);
2990 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
2992 return match_records(hash
, buff
, len
, NULL
, 0);
2996 ftrace_match_module_records(struct ftrace_hash
*hash
, char *buff
, char *mod
)
3000 /* blank or '*' mean the same */
3001 if (strcmp(buff
, "*") == 0)
3004 /* handle the case of 'dont filter this module' */
3005 if (strcmp(buff
, "!") == 0 || strcmp(buff
, "!*") == 0) {
3010 return match_records(hash
, buff
, strlen(buff
), mod
, not);
3014 * We register the module command as a template to show others how
3015 * to register the a command as well.
3019 ftrace_mod_callback(struct ftrace_hash
*hash
,
3020 char *func
, char *cmd
, char *param
, int enable
)
3026 * cmd == 'mod' because we only registered this func
3027 * for the 'mod' ftrace_func_command.
3028 * But if you register one func with multiple commands,
3029 * you can tell which command was used by the cmd
3033 /* we must have a module name */
3037 mod
= strsep(¶m
, ":");
3041 ret
= ftrace_match_module_records(hash
, func
, mod
);
3050 static struct ftrace_func_command ftrace_mod_cmd
= {
3052 .func
= ftrace_mod_callback
,
3055 static int __init
ftrace_mod_cmd_init(void)
3057 return register_ftrace_command(&ftrace_mod_cmd
);
3059 core_initcall(ftrace_mod_cmd_init
);
3061 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
3062 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3064 struct ftrace_func_probe
*entry
;
3065 struct hlist_head
*hhd
;
3068 key
= hash_long(ip
, FTRACE_HASH_BITS
);
3070 hhd
= &ftrace_func_hash
[key
];
3072 if (hlist_empty(hhd
))
3076 * Disable preemption for these calls to prevent a RCU grace
3077 * period. This syncs the hash iteration and freeing of items
3078 * on the hash. rcu_read_lock is too dangerous here.
3080 preempt_disable_notrace();
3081 hlist_for_each_entry_rcu_notrace(entry
, hhd
, node
) {
3082 if (entry
->ip
== ip
)
3083 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
3085 preempt_enable_notrace();
3088 static struct ftrace_ops trace_probe_ops __read_mostly
=
3090 .func
= function_trace_probe_call
,
3091 .flags
= FTRACE_OPS_FL_INITIALIZED
,
3092 INIT_REGEX_LOCK(trace_probe_ops
)
3095 static int ftrace_probe_registered
;
3097 static void __enable_ftrace_function_probe(void)
3102 if (ftrace_probe_registered
) {
3103 /* still need to update the function call sites */
3105 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3109 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3110 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3114 /* Nothing registered? */
3115 if (i
== FTRACE_FUNC_HASHSIZE
)
3118 ret
= ftrace_startup(&trace_probe_ops
, 0);
3120 ftrace_probe_registered
= 1;
3123 static void __disable_ftrace_function_probe(void)
3127 if (!ftrace_probe_registered
)
3130 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3131 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3136 /* no more funcs left */
3137 ftrace_shutdown(&trace_probe_ops
, 0);
3139 ftrace_probe_registered
= 0;
3143 static void ftrace_free_entry(struct ftrace_func_probe
*entry
)
3145 if (entry
->ops
->free
)
3146 entry
->ops
->free(entry
->ops
, entry
->ip
, &entry
->data
);
3151 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3154 struct ftrace_func_probe
*entry
;
3155 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.filter_hash
;
3156 struct ftrace_hash
*hash
;
3157 struct ftrace_page
*pg
;
3158 struct dyn_ftrace
*rec
;
3165 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3166 len
= strlen(search
);
3168 /* we do not support '!' for function probes */
3172 mutex_lock(&trace_probe_ops
.regex_lock
);
3174 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3180 if (unlikely(ftrace_disabled
)) {
3185 mutex_lock(&ftrace_lock
);
3187 do_for_each_ftrace_rec(pg
, rec
) {
3189 if (!ftrace_match_record(rec
, NULL
, search
, len
, type
))
3192 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3194 /* If we did not process any, then return error */
3205 * The caller might want to do something special
3206 * for each function we find. We call the callback
3207 * to give the caller an opportunity to do so.
3210 if (ops
->init(ops
, rec
->ip
, &entry
->data
) < 0) {
3211 /* caller does not like this func */
3217 ret
= enter_record(hash
, rec
, 0);
3225 entry
->ip
= rec
->ip
;
3227 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3228 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3230 } while_for_each_ftrace_rec();
3232 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3236 __enable_ftrace_function_probe();
3239 mutex_unlock(&ftrace_lock
);
3241 mutex_unlock(&trace_probe_ops
.regex_lock
);
3242 free_ftrace_hash(hash
);
3248 PROBE_TEST_FUNC
= 1,
3253 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3254 void *data
, int flags
)
3256 struct ftrace_func_entry
*rec_entry
;
3257 struct ftrace_func_probe
*entry
;
3258 struct ftrace_func_probe
*p
;
3259 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.filter_hash
;
3260 struct list_head free_list
;
3261 struct ftrace_hash
*hash
;
3262 struct hlist_node
*tmp
;
3263 char str
[KSYM_SYMBOL_LEN
];
3264 int type
= MATCH_FULL
;
3268 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3273 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3274 len
= strlen(search
);
3276 /* we do not support '!' for function probes */
3281 mutex_lock(&trace_probe_ops
.regex_lock
);
3283 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3285 /* Hmm, should report this somehow */
3288 INIT_LIST_HEAD(&free_list
);
3290 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3291 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3293 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3295 /* break up if statements for readability */
3296 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3299 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3302 /* do this last, since it is the most expensive */
3304 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3306 if (!ftrace_match(str
, glob
, len
, type
))
3310 rec_entry
= ftrace_lookup_ip(hash
, entry
->ip
);
3311 /* It is possible more than one entry had this ip */
3313 free_hash_entry(hash
, rec_entry
);
3315 hlist_del_rcu(&entry
->node
);
3316 list_add(&entry
->free_list
, &free_list
);
3319 mutex_lock(&ftrace_lock
);
3320 __disable_ftrace_function_probe();
3322 * Remove after the disable is called. Otherwise, if the last
3323 * probe is removed, a null hash means *all enabled*.
3325 ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3326 synchronize_sched();
3327 list_for_each_entry_safe(entry
, p
, &free_list
, free_list
) {
3328 list_del(&entry
->free_list
);
3329 ftrace_free_entry(entry
);
3331 mutex_unlock(&ftrace_lock
);
3334 mutex_unlock(&trace_probe_ops
.regex_lock
);
3335 free_ftrace_hash(hash
);
3339 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3342 __unregister_ftrace_function_probe(glob
, ops
, data
,
3343 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3347 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3349 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3352 void unregister_ftrace_function_probe_all(char *glob
)
3354 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3357 static LIST_HEAD(ftrace_commands
);
3358 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3360 int register_ftrace_command(struct ftrace_func_command
*cmd
)
3362 struct ftrace_func_command
*p
;
3365 mutex_lock(&ftrace_cmd_mutex
);
3366 list_for_each_entry(p
, &ftrace_commands
, list
) {
3367 if (strcmp(cmd
->name
, p
->name
) == 0) {
3372 list_add(&cmd
->list
, &ftrace_commands
);
3374 mutex_unlock(&ftrace_cmd_mutex
);
3379 int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
3381 struct ftrace_func_command
*p
, *n
;
3384 mutex_lock(&ftrace_cmd_mutex
);
3385 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
3386 if (strcmp(cmd
->name
, p
->name
) == 0) {
3388 list_del_init(&p
->list
);
3393 mutex_unlock(&ftrace_cmd_mutex
);
3398 static int ftrace_process_regex(struct ftrace_hash
*hash
,
3399 char *buff
, int len
, int enable
)
3401 char *func
, *command
, *next
= buff
;
3402 struct ftrace_func_command
*p
;
3405 func
= strsep(&next
, ":");
3408 ret
= ftrace_match_records(hash
, func
, len
);
3418 command
= strsep(&next
, ":");
3420 mutex_lock(&ftrace_cmd_mutex
);
3421 list_for_each_entry(p
, &ftrace_commands
, list
) {
3422 if (strcmp(p
->name
, command
) == 0) {
3423 ret
= p
->func(hash
, func
, command
, next
, enable
);
3428 mutex_unlock(&ftrace_cmd_mutex
);
3434 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
3435 size_t cnt
, loff_t
*ppos
, int enable
)
3437 struct ftrace_iterator
*iter
;
3438 struct trace_parser
*parser
;
3444 if (file
->f_mode
& FMODE_READ
) {
3445 struct seq_file
*m
= file
->private_data
;
3448 iter
= file
->private_data
;
3450 if (unlikely(ftrace_disabled
))
3453 /* iter->hash is a local copy, so we don't need regex_lock */
3455 parser
= &iter
->parser
;
3456 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
3458 if (read
>= 0 && trace_parser_loaded(parser
) &&
3459 !trace_parser_cont(parser
)) {
3460 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
3461 parser
->idx
, enable
);
3462 trace_parser_clear(parser
);
3473 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
3474 size_t cnt
, loff_t
*ppos
)
3476 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
3480 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
3481 size_t cnt
, loff_t
*ppos
)
3483 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
3487 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
3489 struct ftrace_func_entry
*entry
;
3491 if (!ftrace_location(ip
))
3495 entry
= ftrace_lookup_ip(hash
, ip
);
3498 free_hash_entry(hash
, entry
);
3502 return add_hash_entry(hash
, ip
);
3506 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3507 unsigned long ip
, int remove
, int reset
, int enable
)
3509 struct ftrace_hash
**orig_hash
;
3510 struct ftrace_hash
*hash
;
3513 /* All global ops uses the global ops filters */
3514 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
)
3517 if (unlikely(ftrace_disabled
))
3520 mutex_lock(&ops
->regex_lock
);
3523 orig_hash
= &ops
->filter_hash
;
3525 orig_hash
= &ops
->notrace_hash
;
3527 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3530 goto out_regex_unlock
;
3534 ftrace_filter_reset(hash
);
3535 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
3537 goto out_regex_unlock
;
3540 ret
= ftrace_match_addr(hash
, ip
, remove
);
3542 goto out_regex_unlock
;
3545 mutex_lock(&ftrace_lock
);
3546 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3547 if (!ret
&& ops
->flags
& FTRACE_OPS_FL_ENABLED
3549 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3551 mutex_unlock(&ftrace_lock
);
3554 mutex_unlock(&ops
->regex_lock
);
3556 free_ftrace_hash(hash
);
3561 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
3562 int reset
, int enable
)
3564 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
3568 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3569 * @ops - the ops to set the filter with
3570 * @ip - the address to add to or remove from the filter.
3571 * @remove - non zero to remove the ip from the filter
3572 * @reset - non zero to reset all filters before applying this filter.
3574 * Filters denote which functions should be enabled when tracing is enabled
3575 * If @ip is NULL, it failes to update filter.
3577 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
3578 int remove
, int reset
)
3580 ftrace_ops_init(ops
);
3581 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
3583 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
3586 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3587 int reset
, int enable
)
3589 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
3593 * ftrace_set_filter - set a function to filter on in ftrace
3594 * @ops - the ops to set the filter with
3595 * @buf - the string that holds the function filter text.
3596 * @len - the length of the string.
3597 * @reset - non zero to reset all filters before applying this filter.
3599 * Filters denote which functions should be enabled when tracing is enabled.
3600 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3602 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
3605 ftrace_ops_init(ops
);
3606 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
3608 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
3611 * ftrace_set_notrace - set a function to not trace in ftrace
3612 * @ops - the ops to set the notrace filter with
3613 * @buf - the string that holds the function notrace text.
3614 * @len - the length of the string.
3615 * @reset - non zero to reset all filters before applying this filter.
3617 * Notrace Filters denote which functions should not be enabled when tracing
3618 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3621 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
3624 ftrace_ops_init(ops
);
3625 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
3627 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
3629 * ftrace_set_filter - set a function to filter on in ftrace
3630 * @ops - the ops to set the filter with
3631 * @buf - the string that holds the function filter text.
3632 * @len - the length of the string.
3633 * @reset - non zero to reset all filters before applying this filter.
3635 * Filters denote which functions should be enabled when tracing is enabled.
3636 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3638 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
3640 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
3642 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
3645 * ftrace_set_notrace - set a function to not trace in ftrace
3646 * @ops - the ops to set the notrace filter with
3647 * @buf - the string that holds the function notrace text.
3648 * @len - the length of the string.
3649 * @reset - non zero to reset all filters before applying this filter.
3651 * Notrace Filters denote which functions should not be enabled when tracing
3652 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3655 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
3657 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
3659 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
3662 * command line interface to allow users to set filters on boot up.
3664 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3665 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3666 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3668 static int __init
set_ftrace_notrace(char *str
)
3670 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
3673 __setup("ftrace_notrace=", set_ftrace_notrace
);
3675 static int __init
set_ftrace_filter(char *str
)
3677 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
3680 __setup("ftrace_filter=", set_ftrace_filter
);
3682 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3683 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3684 static int ftrace_set_func(unsigned long *array
, int *idx
, char *buffer
);
3686 static int __init
set_graph_function(char *str
)
3688 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
3691 __setup("ftrace_graph_filter=", set_graph_function
);
3693 static void __init
set_ftrace_early_graph(char *buf
)
3699 func
= strsep(&buf
, ",");
3700 /* we allow only one expression at a time */
3701 ret
= ftrace_set_func(ftrace_graph_funcs
, &ftrace_graph_count
,
3704 printk(KERN_DEBUG
"ftrace: function %s not "
3705 "traceable\n", func
);
3708 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3711 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
3715 ftrace_ops_init(ops
);
3718 func
= strsep(&buf
, ",");
3719 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
3723 static void __init
set_ftrace_early_filters(void)
3725 if (ftrace_filter_buf
[0])
3726 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
3727 if (ftrace_notrace_buf
[0])
3728 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
3729 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3730 if (ftrace_graph_buf
[0])
3731 set_ftrace_early_graph(ftrace_graph_buf
);
3732 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3735 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
3737 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
3738 struct ftrace_iterator
*iter
;
3739 struct ftrace_hash
**orig_hash
;
3740 struct trace_parser
*parser
;
3744 if (file
->f_mode
& FMODE_READ
) {
3746 seq_release(inode
, file
);
3748 iter
= file
->private_data
;
3750 parser
= &iter
->parser
;
3751 if (trace_parser_loaded(parser
)) {
3752 parser
->buffer
[parser
->idx
] = 0;
3753 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
3756 trace_parser_put(parser
);
3758 mutex_lock(&iter
->ops
->regex_lock
);
3760 if (file
->f_mode
& FMODE_WRITE
) {
3761 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
3764 orig_hash
= &iter
->ops
->filter_hash
;
3766 orig_hash
= &iter
->ops
->notrace_hash
;
3768 mutex_lock(&ftrace_lock
);
3769 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
3770 orig_hash
, iter
->hash
);
3771 if (!ret
&& (iter
->ops
->flags
& FTRACE_OPS_FL_ENABLED
)
3773 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3775 mutex_unlock(&ftrace_lock
);
3778 mutex_unlock(&iter
->ops
->regex_lock
);
3779 free_ftrace_hash(iter
->hash
);
3785 static const struct file_operations ftrace_avail_fops
= {
3786 .open
= ftrace_avail_open
,
3788 .llseek
= seq_lseek
,
3789 .release
= seq_release_private
,
3792 static const struct file_operations ftrace_enabled_fops
= {
3793 .open
= ftrace_enabled_open
,
3795 .llseek
= seq_lseek
,
3796 .release
= seq_release_private
,
3799 static const struct file_operations ftrace_filter_fops
= {
3800 .open
= ftrace_filter_open
,
3802 .write
= ftrace_filter_write
,
3803 .llseek
= ftrace_filter_lseek
,
3804 .release
= ftrace_regex_release
,
3807 static const struct file_operations ftrace_notrace_fops
= {
3808 .open
= ftrace_notrace_open
,
3810 .write
= ftrace_notrace_write
,
3811 .llseek
= ftrace_filter_lseek
,
3812 .release
= ftrace_regex_release
,
3815 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3817 static DEFINE_MUTEX(graph_lock
);
3819 int ftrace_graph_count
;
3820 int ftrace_graph_filter_enabled
;
3821 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
3824 __g_next(struct seq_file
*m
, loff_t
*pos
)
3826 if (*pos
>= ftrace_graph_count
)
3828 return &ftrace_graph_funcs
[*pos
];
3832 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3835 return __g_next(m
, pos
);
3838 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
3840 mutex_lock(&graph_lock
);
3842 /* Nothing, tell g_show to print all functions are enabled */
3843 if (!ftrace_graph_filter_enabled
&& !*pos
)
3846 return __g_next(m
, pos
);
3849 static void g_stop(struct seq_file
*m
, void *p
)
3851 mutex_unlock(&graph_lock
);
3854 static int g_show(struct seq_file
*m
, void *v
)
3856 unsigned long *ptr
= v
;
3861 if (ptr
== (unsigned long *)1) {
3862 seq_printf(m
, "#### all functions enabled ####\n");
3866 seq_printf(m
, "%ps\n", (void *)*ptr
);
3871 static const struct seq_operations ftrace_graph_seq_ops
= {
3879 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
3883 if (unlikely(ftrace_disabled
))
3886 mutex_lock(&graph_lock
);
3887 if ((file
->f_mode
& FMODE_WRITE
) &&
3888 (file
->f_flags
& O_TRUNC
)) {
3889 ftrace_graph_filter_enabled
= 0;
3890 ftrace_graph_count
= 0;
3891 memset(ftrace_graph_funcs
, 0, sizeof(ftrace_graph_funcs
));
3893 mutex_unlock(&graph_lock
);
3895 if (file
->f_mode
& FMODE_READ
)
3896 ret
= seq_open(file
, &ftrace_graph_seq_ops
);
3902 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
3904 if (file
->f_mode
& FMODE_READ
)
3905 seq_release(inode
, file
);
3910 ftrace_set_func(unsigned long *array
, int *idx
, char *buffer
)
3912 struct dyn_ftrace
*rec
;
3913 struct ftrace_page
*pg
;
3922 type
= filter_parse_regex(buffer
, strlen(buffer
), &search
, ¬);
3923 if (!not && *idx
>= FTRACE_GRAPH_MAX_FUNCS
)
3926 search_len
= strlen(search
);
3928 mutex_lock(&ftrace_lock
);
3930 if (unlikely(ftrace_disabled
)) {
3931 mutex_unlock(&ftrace_lock
);
3935 do_for_each_ftrace_rec(pg
, rec
) {
3937 if (ftrace_match_record(rec
, NULL
, search
, search_len
, type
)) {
3938 /* if it is in the array */
3940 for (i
= 0; i
< *idx
; i
++) {
3941 if (array
[i
] == rec
->ip
) {
3950 array
[(*idx
)++] = rec
->ip
;
3951 if (*idx
>= FTRACE_GRAPH_MAX_FUNCS
)
3956 array
[i
] = array
[--(*idx
)];
3962 } while_for_each_ftrace_rec();
3964 mutex_unlock(&ftrace_lock
);
3969 ftrace_graph_filter_enabled
= !!(*idx
);
3975 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
3976 size_t cnt
, loff_t
*ppos
)
3978 struct trace_parser parser
;
3984 mutex_lock(&graph_lock
);
3986 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
)) {
3991 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
3993 if (read
>= 0 && trace_parser_loaded((&parser
))) {
3994 parser
.buffer
[parser
.idx
] = 0;
3996 /* we allow only one expression at a time */
3997 ret
= ftrace_set_func(ftrace_graph_funcs
, &ftrace_graph_count
,
4006 trace_parser_put(&parser
);
4008 mutex_unlock(&graph_lock
);
4013 static const struct file_operations ftrace_graph_fops
= {
4014 .open
= ftrace_graph_open
,
4016 .write
= ftrace_graph_write
,
4017 .llseek
= ftrace_filter_lseek
,
4018 .release
= ftrace_graph_release
,
4020 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4022 static __init
int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
)
4025 trace_create_file("available_filter_functions", 0444,
4026 d_tracer
, NULL
, &ftrace_avail_fops
);
4028 trace_create_file("enabled_functions", 0444,
4029 d_tracer
, NULL
, &ftrace_enabled_fops
);
4031 trace_create_file("set_ftrace_filter", 0644, d_tracer
,
4032 NULL
, &ftrace_filter_fops
);
4034 trace_create_file("set_ftrace_notrace", 0644, d_tracer
,
4035 NULL
, &ftrace_notrace_fops
);
4037 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4038 trace_create_file("set_graph_function", 0444, d_tracer
,
4040 &ftrace_graph_fops
);
4041 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4046 static int ftrace_cmp_ips(const void *a
, const void *b
)
4048 const unsigned long *ipa
= a
;
4049 const unsigned long *ipb
= b
;
4058 static void ftrace_swap_ips(void *a
, void *b
, int size
)
4060 unsigned long *ipa
= a
;
4061 unsigned long *ipb
= b
;
4069 static int ftrace_process_locs(struct module
*mod
,
4070 unsigned long *start
,
4073 struct ftrace_page
*start_pg
;
4074 struct ftrace_page
*pg
;
4075 struct dyn_ftrace
*rec
;
4076 unsigned long count
;
4079 unsigned long flags
= 0; /* Shut up gcc */
4082 count
= end
- start
;
4087 sort(start
, count
, sizeof(*start
),
4088 ftrace_cmp_ips
, ftrace_swap_ips
);
4090 start_pg
= ftrace_allocate_pages(count
);
4094 mutex_lock(&ftrace_lock
);
4097 * Core and each module needs their own pages, as
4098 * modules will free them when they are removed.
4099 * Force a new page to be allocated for modules.
4102 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
4103 /* First initialization */
4104 ftrace_pages
= ftrace_pages_start
= start_pg
;
4109 if (WARN_ON(ftrace_pages
->next
)) {
4110 /* Hmm, we have free pages? */
4111 while (ftrace_pages
->next
)
4112 ftrace_pages
= ftrace_pages
->next
;
4115 ftrace_pages
->next
= start_pg
;
4121 addr
= ftrace_call_adjust(*p
++);
4123 * Some architecture linkers will pad between
4124 * the different mcount_loc sections of different
4125 * object files to satisfy alignments.
4126 * Skip any NULL pointers.
4131 if (pg
->index
== pg
->size
) {
4132 /* We should have allocated enough */
4133 if (WARN_ON(!pg
->next
))
4138 rec
= &pg
->records
[pg
->index
++];
4142 /* We should have used all pages */
4145 /* Assign the last page to ftrace_pages */
4148 /* These new locations need to be initialized */
4149 ftrace_new_pgs
= start_pg
;
4152 * We only need to disable interrupts on start up
4153 * because we are modifying code that an interrupt
4154 * may execute, and the modification is not atomic.
4155 * But for modules, nothing runs the code we modify
4156 * until we are finished with it, and there's no
4157 * reason to cause large interrupt latencies while we do it.
4160 local_irq_save(flags
);
4161 ftrace_update_code(mod
);
4163 local_irq_restore(flags
);
4166 mutex_unlock(&ftrace_lock
);
4171 #ifdef CONFIG_MODULES
4173 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4175 void ftrace_release_mod(struct module
*mod
)
4177 struct dyn_ftrace
*rec
;
4178 struct ftrace_page
**last_pg
;
4179 struct ftrace_page
*pg
;
4182 mutex_lock(&ftrace_lock
);
4184 if (ftrace_disabled
)
4188 * Each module has its own ftrace_pages, remove
4189 * them from the list.
4191 last_pg
= &ftrace_pages_start
;
4192 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
4193 rec
= &pg
->records
[0];
4194 if (within_module_core(rec
->ip
, mod
)) {
4196 * As core pages are first, the first
4197 * page should never be a module page.
4199 if (WARN_ON(pg
== ftrace_pages_start
))
4202 /* Check if we are deleting the last page */
4203 if (pg
== ftrace_pages
)
4204 ftrace_pages
= next_to_ftrace_page(last_pg
);
4206 *last_pg
= pg
->next
;
4207 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
4208 free_pages((unsigned long)pg
->records
, order
);
4211 last_pg
= &pg
->next
;
4214 mutex_unlock(&ftrace_lock
);
4217 static void ftrace_init_module(struct module
*mod
,
4218 unsigned long *start
, unsigned long *end
)
4220 if (ftrace_disabled
|| start
== end
)
4222 ftrace_process_locs(mod
, start
, end
);
4225 void ftrace_module_init(struct module
*mod
)
4227 ftrace_init_module(mod
, mod
->ftrace_callsites
,
4228 mod
->ftrace_callsites
+
4229 mod
->num_ftrace_callsites
);
4232 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4233 unsigned long val
, void *data
)
4235 struct module
*mod
= data
;
4237 if (val
== MODULE_STATE_GOING
)
4238 ftrace_release_mod(mod
);
4243 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4244 unsigned long val
, void *data
)
4248 #endif /* CONFIG_MODULES */
4250 struct notifier_block ftrace_module_exit_nb
= {
4251 .notifier_call
= ftrace_module_notify_exit
,
4252 .priority
= INT_MIN
, /* Run after anything that can remove kprobes */
4255 extern unsigned long __start_mcount_loc
[];
4256 extern unsigned long __stop_mcount_loc
[];
4258 void __init
ftrace_init(void)
4260 unsigned long count
, flags
;
4263 local_irq_save(flags
);
4264 ret
= ftrace_dyn_arch_init();
4265 local_irq_restore(flags
);
4269 count
= __stop_mcount_loc
- __start_mcount_loc
;
4271 ret
= ftrace_dyn_table_alloc(count
);
4275 last_ftrace_enabled
= ftrace_enabled
= 1;
4277 ret
= ftrace_process_locs(NULL
,
4281 ret
= register_module_notifier(&ftrace_module_exit_nb
);
4283 pr_warning("Failed to register trace ftrace module exit notifier\n");
4285 set_ftrace_early_filters();
4289 ftrace_disabled
= 1;
4294 static struct ftrace_ops global_ops
= {
4295 .func
= ftrace_stub
,
4296 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4297 INIT_REGEX_LOCK(global_ops
)
4300 static int __init
ftrace_nodyn_init(void)
4305 core_initcall(ftrace_nodyn_init
);
4307 static inline int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
) { return 0; }
4308 static inline void ftrace_startup_enable(int command
) { }
4309 /* Keep as macros so we do not need to define the commands */
4310 # define ftrace_startup(ops, command) \
4312 int ___ret = __register_ftrace_function(ops); \
4314 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4317 # define ftrace_shutdown(ops, command) __unregister_ftrace_function(ops)
4319 # define ftrace_startup_sysctl() do { } while (0)
4320 # define ftrace_shutdown_sysctl() do { } while (0)
4323 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
4328 #endif /* CONFIG_DYNAMIC_FTRACE */
4331 ftrace_ops_control_func(unsigned long ip
, unsigned long parent_ip
,
4332 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4334 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT
)))
4338 * Some of the ops may be dynamically allocated,
4339 * they must be freed after a synchronize_sched().
4341 preempt_disable_notrace();
4342 trace_recursion_set(TRACE_CONTROL_BIT
);
4343 do_for_each_ftrace_op(op
, ftrace_control_list
) {
4344 if (!(op
->flags
& FTRACE_OPS_FL_STUB
) &&
4345 !ftrace_function_local_disabled(op
) &&
4346 ftrace_ops_test(op
, ip
, regs
))
4347 op
->func(ip
, parent_ip
, op
, regs
);
4348 } while_for_each_ftrace_op(op
);
4349 trace_recursion_clear(TRACE_CONTROL_BIT
);
4350 preempt_enable_notrace();
4353 static struct ftrace_ops control_ops
= {
4354 .func
= ftrace_ops_control_func
,
4355 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4356 INIT_REGEX_LOCK(control_ops
)
4360 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4361 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
4363 struct ftrace_ops
*op
;
4366 if (function_trace_stop
)
4369 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
4374 * Some of the ops may be dynamically allocated,
4375 * they must be freed after a synchronize_sched().
4377 preempt_disable_notrace();
4378 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4379 if (ftrace_ops_test(op
, ip
, regs
))
4380 op
->func(ip
, parent_ip
, op
, regs
);
4381 } while_for_each_ftrace_op(op
);
4382 preempt_enable_notrace();
4383 trace_clear_recursion(bit
);
4387 * Some archs only support passing ip and parent_ip. Even though
4388 * the list function ignores the op parameter, we do not want any
4389 * C side effects, where a function is called without the caller
4390 * sending a third parameter.
4391 * Archs are to support both the regs and ftrace_ops at the same time.
4392 * If they support ftrace_ops, it is assumed they support regs.
4393 * If call backs want to use regs, they must either check for regs
4394 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4395 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4396 * An architecture can pass partial regs with ftrace_ops and still
4397 * set the ARCH_SUPPORT_FTARCE_OPS.
4399 #if ARCH_SUPPORTS_FTRACE_OPS
4400 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4401 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4403 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
4406 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
4408 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
4412 static void clear_ftrace_swapper(void)
4414 struct task_struct
*p
;
4418 for_each_online_cpu(cpu
) {
4420 clear_tsk_trace_trace(p
);
4425 static void set_ftrace_swapper(void)
4427 struct task_struct
*p
;
4431 for_each_online_cpu(cpu
) {
4433 set_tsk_trace_trace(p
);
4438 static void clear_ftrace_pid(struct pid
*pid
)
4440 struct task_struct
*p
;
4443 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4444 clear_tsk_trace_trace(p
);
4445 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4451 static void set_ftrace_pid(struct pid
*pid
)
4453 struct task_struct
*p
;
4456 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4457 set_tsk_trace_trace(p
);
4458 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4462 static void clear_ftrace_pid_task(struct pid
*pid
)
4464 if (pid
== ftrace_swapper_pid
)
4465 clear_ftrace_swapper();
4467 clear_ftrace_pid(pid
);
4470 static void set_ftrace_pid_task(struct pid
*pid
)
4472 if (pid
== ftrace_swapper_pid
)
4473 set_ftrace_swapper();
4475 set_ftrace_pid(pid
);
4478 static int ftrace_pid_add(int p
)
4481 struct ftrace_pid
*fpid
;
4484 mutex_lock(&ftrace_lock
);
4487 pid
= ftrace_swapper_pid
;
4489 pid
= find_get_pid(p
);
4496 list_for_each_entry(fpid
, &ftrace_pids
, list
)
4497 if (fpid
->pid
== pid
)
4502 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
4506 list_add(&fpid
->list
, &ftrace_pids
);
4509 set_ftrace_pid_task(pid
);
4511 ftrace_update_pid_func();
4512 ftrace_startup_enable(0);
4514 mutex_unlock(&ftrace_lock
);
4518 if (pid
!= ftrace_swapper_pid
)
4522 mutex_unlock(&ftrace_lock
);
4526 static void ftrace_pid_reset(void)
4528 struct ftrace_pid
*fpid
, *safe
;
4530 mutex_lock(&ftrace_lock
);
4531 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
4532 struct pid
*pid
= fpid
->pid
;
4534 clear_ftrace_pid_task(pid
);
4536 list_del(&fpid
->list
);
4540 ftrace_update_pid_func();
4541 ftrace_startup_enable(0);
4543 mutex_unlock(&ftrace_lock
);
4546 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
4548 mutex_lock(&ftrace_lock
);
4550 if (list_empty(&ftrace_pids
) && (!*pos
))
4553 return seq_list_start(&ftrace_pids
, *pos
);
4556 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4561 return seq_list_next(v
, &ftrace_pids
, pos
);
4564 static void fpid_stop(struct seq_file
*m
, void *p
)
4566 mutex_unlock(&ftrace_lock
);
4569 static int fpid_show(struct seq_file
*m
, void *v
)
4571 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
4573 if (v
== (void *)1) {
4574 seq_printf(m
, "no pid\n");
4578 if (fpid
->pid
== ftrace_swapper_pid
)
4579 seq_printf(m
, "swapper tasks\n");
4581 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
4586 static const struct seq_operations ftrace_pid_sops
= {
4587 .start
= fpid_start
,
4594 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
4598 if ((file
->f_mode
& FMODE_WRITE
) &&
4599 (file
->f_flags
& O_TRUNC
))
4602 if (file
->f_mode
& FMODE_READ
)
4603 ret
= seq_open(file
, &ftrace_pid_sops
);
4609 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
4610 size_t cnt
, loff_t
*ppos
)
4616 if (cnt
>= sizeof(buf
))
4619 if (copy_from_user(&buf
, ubuf
, cnt
))
4625 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4626 * to clean the filter quietly.
4628 tmp
= strstrip(buf
);
4629 if (strlen(tmp
) == 0)
4632 ret
= kstrtol(tmp
, 10, &val
);
4636 ret
= ftrace_pid_add(val
);
4638 return ret
? ret
: cnt
;
4642 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
4644 if (file
->f_mode
& FMODE_READ
)
4645 seq_release(inode
, file
);
4650 static const struct file_operations ftrace_pid_fops
= {
4651 .open
= ftrace_pid_open
,
4652 .write
= ftrace_pid_write
,
4654 .llseek
= ftrace_filter_lseek
,
4655 .release
= ftrace_pid_release
,
4658 static __init
int ftrace_init_debugfs(void)
4660 struct dentry
*d_tracer
;
4662 d_tracer
= tracing_init_dentry();
4666 ftrace_init_dyn_debugfs(d_tracer
);
4668 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
4669 NULL
, &ftrace_pid_fops
);
4671 ftrace_profile_debugfs(d_tracer
);
4675 fs_initcall(ftrace_init_debugfs
);
4678 * ftrace_kill - kill ftrace
4680 * This function should be used by panic code. It stops ftrace
4681 * but in a not so nice way. If you need to simply kill ftrace
4682 * from a non-atomic section, use ftrace_kill.
4684 void ftrace_kill(void)
4686 ftrace_disabled
= 1;
4688 clear_ftrace_function();
4692 * Test if ftrace is dead or not.
4694 int ftrace_is_dead(void)
4696 return ftrace_disabled
;
4700 * register_ftrace_function - register a function for profiling
4701 * @ops - ops structure that holds the function for profiling.
4703 * Register a function to be called by all functions in the
4706 * Note: @ops->func and all the functions it calls must be labeled
4707 * with "notrace", otherwise it will go into a
4710 int register_ftrace_function(struct ftrace_ops
*ops
)
4714 ftrace_ops_init(ops
);
4716 mutex_lock(&ftrace_lock
);
4718 ret
= ftrace_startup(ops
, 0);
4720 mutex_unlock(&ftrace_lock
);
4724 EXPORT_SYMBOL_GPL(register_ftrace_function
);
4727 * unregister_ftrace_function - unregister a function for profiling.
4728 * @ops - ops structure that holds the function to unregister
4730 * Unregister a function that was added to be called by ftrace profiling.
4732 int unregister_ftrace_function(struct ftrace_ops
*ops
)
4736 mutex_lock(&ftrace_lock
);
4737 ret
= ftrace_shutdown(ops
, 0);
4738 mutex_unlock(&ftrace_lock
);
4742 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
4745 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
4746 void __user
*buffer
, size_t *lenp
,
4751 mutex_lock(&ftrace_lock
);
4753 if (unlikely(ftrace_disabled
))
4756 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
4758 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
4761 last_ftrace_enabled
= !!ftrace_enabled
;
4763 if (ftrace_enabled
) {
4765 ftrace_startup_sysctl();
4767 /* we are starting ftrace again */
4768 if (ftrace_ops_list
!= &ftrace_list_end
)
4769 update_ftrace_function();
4772 /* stopping ftrace calls (just send to ftrace_stub) */
4773 ftrace_trace_function
= ftrace_stub
;
4775 ftrace_shutdown_sysctl();
4779 mutex_unlock(&ftrace_lock
);
4783 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4785 static int ftrace_graph_active
;
4786 static struct notifier_block ftrace_suspend_notifier
;
4788 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
4793 /* The callbacks that hook a function */
4794 trace_func_graph_ret_t ftrace_graph_return
=
4795 (trace_func_graph_ret_t
)ftrace_stub
;
4796 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
4797 static trace_func_graph_ent_t __ftrace_graph_entry
= ftrace_graph_entry_stub
;
4799 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
4800 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
4804 unsigned long flags
;
4805 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
4806 struct task_struct
*g
, *t
;
4808 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
4809 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
4810 * sizeof(struct ftrace_ret_stack
),
4812 if (!ret_stack_list
[i
]) {
4820 read_lock_irqsave(&tasklist_lock
, flags
);
4821 do_each_thread(g
, t
) {
4827 if (t
->ret_stack
== NULL
) {
4828 atomic_set(&t
->tracing_graph_pause
, 0);
4829 atomic_set(&t
->trace_overrun
, 0);
4830 t
->curr_ret_stack
= -1;
4831 /* Make sure the tasks see the -1 first: */
4833 t
->ret_stack
= ret_stack_list
[start
++];
4835 } while_each_thread(g
, t
);
4838 read_unlock_irqrestore(&tasklist_lock
, flags
);
4840 for (i
= start
; i
< end
; i
++)
4841 kfree(ret_stack_list
[i
]);
4846 ftrace_graph_probe_sched_switch(void *ignore
,
4847 struct task_struct
*prev
, struct task_struct
*next
)
4849 unsigned long long timestamp
;
4853 * Does the user want to count the time a function was asleep.
4854 * If so, do not update the time stamps.
4856 if (trace_flags
& TRACE_ITER_SLEEP_TIME
)
4859 timestamp
= trace_clock_local();
4861 prev
->ftrace_timestamp
= timestamp
;
4863 /* only process tasks that we timestamped */
4864 if (!next
->ftrace_timestamp
)
4868 * Update all the counters in next to make up for the
4869 * time next was sleeping.
4871 timestamp
-= next
->ftrace_timestamp
;
4873 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
4874 next
->ret_stack
[index
].calltime
+= timestamp
;
4877 /* Allocate a return stack for each task */
4878 static int start_graph_tracing(void)
4880 struct ftrace_ret_stack
**ret_stack_list
;
4883 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
4884 sizeof(struct ftrace_ret_stack
*),
4887 if (!ret_stack_list
)
4890 /* The cpu_boot init_task->ret_stack will never be freed */
4891 for_each_online_cpu(cpu
) {
4892 if (!idle_task(cpu
)->ret_stack
)
4893 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
4897 ret
= alloc_retstack_tasklist(ret_stack_list
);
4898 } while (ret
== -EAGAIN
);
4901 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
4903 pr_info("ftrace_graph: Couldn't activate tracepoint"
4904 " probe to kernel_sched_switch\n");
4907 kfree(ret_stack_list
);
4912 * Hibernation protection.
4913 * The state of the current task is too much unstable during
4914 * suspend/restore to disk. We want to protect against that.
4917 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
4921 case PM_HIBERNATION_PREPARE
:
4922 pause_graph_tracing();
4925 case PM_POST_HIBERNATION
:
4926 unpause_graph_tracing();
4932 /* Just a place holder for function graph */
4933 static struct ftrace_ops fgraph_ops __read_mostly
= {
4934 .func
= ftrace_stub
,
4935 .flags
= FTRACE_OPS_FL_STUB
| FTRACE_OPS_FL_GLOBAL
|
4936 FTRACE_OPS_FL_RECURSION_SAFE
,
4939 static int ftrace_graph_entry_test(struct ftrace_graph_ent
*trace
)
4941 if (!ftrace_ops_test(&global_ops
, trace
->func
, NULL
))
4943 return __ftrace_graph_entry(trace
);
4947 * The function graph tracer should only trace the functions defined
4948 * by set_ftrace_filter and set_ftrace_notrace. If another function
4949 * tracer ops is registered, the graph tracer requires testing the
4950 * function against the global ops, and not just trace any function
4951 * that any ftrace_ops registered.
4953 static void update_function_graph_func(void)
4955 if (ftrace_ops_list
== &ftrace_list_end
||
4956 (ftrace_ops_list
== &global_ops
&&
4957 global_ops
.next
== &ftrace_list_end
))
4958 ftrace_graph_entry
= __ftrace_graph_entry
;
4960 ftrace_graph_entry
= ftrace_graph_entry_test
;
4963 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
4964 trace_func_graph_ent_t entryfunc
)
4968 mutex_lock(&ftrace_lock
);
4970 /* we currently allow only one tracer registered at a time */
4971 if (ftrace_graph_active
) {
4976 ftrace_suspend_notifier
.notifier_call
= ftrace_suspend_notifier_call
;
4977 register_pm_notifier(&ftrace_suspend_notifier
);
4979 ftrace_graph_active
++;
4980 ret
= start_graph_tracing();
4982 ftrace_graph_active
--;
4986 ftrace_graph_return
= retfunc
;
4989 * Update the indirect function to the entryfunc, and the
4990 * function that gets called to the entry_test first. Then
4991 * call the update fgraph entry function to determine if
4992 * the entryfunc should be called directly or not.
4994 __ftrace_graph_entry
= entryfunc
;
4995 ftrace_graph_entry
= ftrace_graph_entry_test
;
4996 update_function_graph_func();
4998 ret
= ftrace_startup(&fgraph_ops
, FTRACE_START_FUNC_RET
);
5001 mutex_unlock(&ftrace_lock
);
5005 void unregister_ftrace_graph(void)
5007 mutex_lock(&ftrace_lock
);
5009 if (unlikely(!ftrace_graph_active
))
5012 ftrace_graph_active
--;
5013 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
5014 ftrace_graph_entry
= ftrace_graph_entry_stub
;
5015 __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5016 ftrace_shutdown(&fgraph_ops
, FTRACE_STOP_FUNC_RET
);
5017 unregister_pm_notifier(&ftrace_suspend_notifier
);
5018 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5021 mutex_unlock(&ftrace_lock
);
5024 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
5027 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
5029 atomic_set(&t
->tracing_graph_pause
, 0);
5030 atomic_set(&t
->trace_overrun
, 0);
5031 t
->ftrace_timestamp
= 0;
5032 /* make curr_ret_stack visible before we add the ret_stack */
5034 t
->ret_stack
= ret_stack
;
5038 * Allocate a return stack for the idle task. May be the first
5039 * time through, or it may be done by CPU hotplug online.
5041 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
5043 t
->curr_ret_stack
= -1;
5045 * The idle task has no parent, it either has its own
5046 * stack or no stack at all.
5049 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
5051 if (ftrace_graph_active
) {
5052 struct ftrace_ret_stack
*ret_stack
;
5054 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
5056 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5057 * sizeof(struct ftrace_ret_stack
),
5061 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
5063 graph_init_task(t
, ret_stack
);
5067 /* Allocate a return stack for newly created task */
5068 void ftrace_graph_init_task(struct task_struct
*t
)
5070 /* Make sure we do not use the parent ret_stack */
5071 t
->ret_stack
= NULL
;
5072 t
->curr_ret_stack
= -1;
5074 if (ftrace_graph_active
) {
5075 struct ftrace_ret_stack
*ret_stack
;
5077 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5078 * sizeof(struct ftrace_ret_stack
),
5082 graph_init_task(t
, ret_stack
);
5086 void ftrace_graph_exit_task(struct task_struct
*t
)
5088 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
5090 t
->ret_stack
= NULL
;
5091 /* NULL must become visible to IRQs before we free it: */
5097 void ftrace_graph_stop(void)