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_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_control_list __read_mostly
= &ftrace_list_end
;
107 static struct ftrace_ops
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
108 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
109 ftrace_func_t ftrace_pid_function __read_mostly
= ftrace_stub
;
110 static struct ftrace_ops global_ops
;
111 static struct ftrace_ops control_ops
;
113 #if ARCH_SUPPORTS_FTRACE_OPS
114 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
115 struct ftrace_ops
*op
, struct pt_regs
*regs
);
117 /* See comment below, where ftrace_ops_list_func is defined */
118 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
119 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
123 * Traverse the ftrace_global_list, invoking all entries. The reason that we
124 * can use rcu_dereference_raw_notrace() is that elements removed from this list
125 * are simply leaked, so there is no need to interact with a grace-period
126 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
127 * concurrent insertions into the ftrace_global_list.
129 * Silly Alpha and silly pointer-speculation compiler optimizations!
131 #define do_for_each_ftrace_op(op, list) \
132 op = rcu_dereference_raw_notrace(list); \
136 * Optimized for just a single item in the list (as that is the normal case).
138 #define while_for_each_ftrace_op(op) \
139 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
140 unlikely((op) != &ftrace_list_end))
142 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
144 #ifdef CONFIG_DYNAMIC_FTRACE
145 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
146 mutex_init(&ops
->regex_lock
);
147 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
153 * ftrace_nr_registered_ops - return number of ops registered
155 * Returns the number of ftrace_ops registered and tracing functions
157 int ftrace_nr_registered_ops(void)
159 struct ftrace_ops
*ops
;
162 mutex_lock(&ftrace_lock
);
164 for (ops
= ftrace_ops_list
;
165 ops
!= &ftrace_list_end
; ops
= ops
->next
)
168 mutex_unlock(&ftrace_lock
);
173 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
174 struct ftrace_ops
*op
, struct pt_regs
*regs
)
176 if (!test_tsk_trace_trace(current
))
179 ftrace_pid_function(ip
, parent_ip
, op
, regs
);
182 static void set_ftrace_pid_function(ftrace_func_t func
)
184 /* do not set ftrace_pid_function to itself! */
185 if (func
!= ftrace_pid_func
)
186 ftrace_pid_function
= func
;
190 * clear_ftrace_function - reset the ftrace function
192 * This NULLs the ftrace function and in essence stops
193 * tracing. There may be lag
195 void clear_ftrace_function(void)
197 ftrace_trace_function
= ftrace_stub
;
198 ftrace_pid_function
= ftrace_stub
;
201 static void control_ops_disable_all(struct ftrace_ops
*ops
)
205 for_each_possible_cpu(cpu
)
206 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
209 static int control_ops_alloc(struct ftrace_ops
*ops
)
211 int __percpu
*disabled
;
213 disabled
= alloc_percpu(int);
217 ops
->disabled
= disabled
;
218 control_ops_disable_all(ops
);
222 static void ftrace_sync(struct work_struct
*work
)
225 * This function is just a stub to implement a hard force
226 * of synchronize_sched(). This requires synchronizing
227 * tasks even in userspace and idle.
229 * Yes, function tracing is rude.
233 static void ftrace_sync_ipi(void *data
)
235 /* Probably not needed, but do it anyway */
239 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
240 static void update_function_graph_func(void);
242 static inline void update_function_graph_func(void) { }
245 static void update_ftrace_function(void)
250 * If we are at the end of the list and this ops is
251 * recursion safe and not dynamic and the arch supports passing ops,
252 * then have the mcount trampoline call the function directly.
254 if (ftrace_ops_list
== &ftrace_list_end
||
255 (ftrace_ops_list
->next
== &ftrace_list_end
&&
256 !(ftrace_ops_list
->flags
& FTRACE_OPS_FL_DYNAMIC
) &&
257 (ftrace_ops_list
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) &&
258 !FTRACE_FORCE_LIST_FUNC
)) {
259 /* Set the ftrace_ops that the arch callback uses */
260 set_function_trace_op
= ftrace_ops_list
;
261 func
= ftrace_ops_list
->func
;
263 /* Just use the default ftrace_ops */
264 set_function_trace_op
= &ftrace_list_end
;
265 func
= ftrace_ops_list_func
;
268 /* If there's no change, then do nothing more here */
269 if (ftrace_trace_function
== func
)
272 update_function_graph_func();
275 * If we are using the list function, it doesn't care
276 * about the function_trace_ops.
278 if (func
== ftrace_ops_list_func
) {
279 ftrace_trace_function
= func
;
281 * Don't even bother setting function_trace_ops,
282 * it would be racy to do so anyway.
287 #ifndef CONFIG_DYNAMIC_FTRACE
289 * For static tracing, we need to be a bit more careful.
290 * The function change takes affect immediately. Thus,
291 * we need to coorditate the setting of the function_trace_ops
292 * with the setting of the ftrace_trace_function.
294 * Set the function to the list ops, which will call the
295 * function we want, albeit indirectly, but it handles the
296 * ftrace_ops and doesn't depend on function_trace_op.
298 ftrace_trace_function
= ftrace_ops_list_func
;
300 * Make sure all CPUs see this. Yes this is slow, but static
301 * tracing is slow and nasty to have enabled.
303 schedule_on_each_cpu(ftrace_sync
);
304 /* Now all cpus are using the list ops. */
305 function_trace_op
= set_function_trace_op
;
306 /* Make sure the function_trace_op is visible on all CPUs */
308 /* Nasty way to force a rmb on all cpus */
309 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
310 /* OK, we are all set to update the ftrace_trace_function now! */
311 #endif /* !CONFIG_DYNAMIC_FTRACE */
313 ftrace_trace_function
= func
;
316 int using_ftrace_ops_list_func(void)
318 return ftrace_trace_function
== ftrace_ops_list_func
;
321 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
325 * We are entering ops into the list but another
326 * CPU might be walking that list. We need to make sure
327 * the ops->next pointer is valid before another CPU sees
328 * the ops pointer included into the list.
330 rcu_assign_pointer(*list
, ops
);
333 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
335 struct ftrace_ops
**p
;
338 * If we are removing the last function, then simply point
339 * to the ftrace_stub.
341 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
342 *list
= &ftrace_list_end
;
346 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
357 static void add_ftrace_list_ops(struct ftrace_ops
**list
,
358 struct ftrace_ops
*main_ops
,
359 struct ftrace_ops
*ops
)
361 int first
= *list
== &ftrace_list_end
;
362 add_ftrace_ops(list
, ops
);
364 add_ftrace_ops(&ftrace_ops_list
, main_ops
);
367 static int remove_ftrace_list_ops(struct ftrace_ops
**list
,
368 struct ftrace_ops
*main_ops
,
369 struct ftrace_ops
*ops
)
371 int ret
= remove_ftrace_ops(list
, ops
);
372 if (!ret
&& *list
== &ftrace_list_end
)
373 ret
= remove_ftrace_ops(&ftrace_ops_list
, main_ops
);
377 static int __register_ftrace_function(struct ftrace_ops
*ops
)
379 if (ops
->flags
& FTRACE_OPS_FL_DELETED
)
382 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
385 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
387 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
388 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
389 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
391 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
392 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
395 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
396 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
399 if (!core_kernel_data((unsigned long)ops
))
400 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
402 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
403 if (control_ops_alloc(ops
))
405 add_ftrace_list_ops(&ftrace_control_list
, &control_ops
, ops
);
407 add_ftrace_ops(&ftrace_ops_list
, ops
);
410 update_ftrace_function();
415 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
419 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
422 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
423 ret
= remove_ftrace_list_ops(&ftrace_control_list
,
426 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
432 update_ftrace_function();
437 static void ftrace_update_pid_func(void)
439 /* Only do something if we are tracing something */
440 if (ftrace_trace_function
== ftrace_stub
)
443 update_ftrace_function();
446 #ifdef CONFIG_FUNCTION_PROFILER
447 struct ftrace_profile
{
448 struct hlist_node node
;
450 unsigned long counter
;
451 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
452 unsigned long long time
;
453 unsigned long long time_squared
;
457 struct ftrace_profile_page
{
458 struct ftrace_profile_page
*next
;
460 struct ftrace_profile records
[];
463 struct ftrace_profile_stat
{
465 struct hlist_head
*hash
;
466 struct ftrace_profile_page
*pages
;
467 struct ftrace_profile_page
*start
;
468 struct tracer_stat stat
;
471 #define PROFILE_RECORDS_SIZE \
472 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
474 #define PROFILES_PER_PAGE \
475 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
477 static int ftrace_profile_enabled __read_mostly
;
479 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
480 static DEFINE_MUTEX(ftrace_profile_lock
);
482 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
484 #define FTRACE_PROFILE_HASH_BITS 10
485 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
488 function_stat_next(void *v
, int idx
)
490 struct ftrace_profile
*rec
= v
;
491 struct ftrace_profile_page
*pg
;
493 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
499 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
503 rec
= &pg
->records
[0];
511 static void *function_stat_start(struct tracer_stat
*trace
)
513 struct ftrace_profile_stat
*stat
=
514 container_of(trace
, struct ftrace_profile_stat
, stat
);
516 if (!stat
|| !stat
->start
)
519 return function_stat_next(&stat
->start
->records
[0], 0);
522 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
523 /* function graph compares on total time */
524 static int function_stat_cmp(void *p1
, void *p2
)
526 struct ftrace_profile
*a
= p1
;
527 struct ftrace_profile
*b
= p2
;
529 if (a
->time
< b
->time
)
531 if (a
->time
> b
->time
)
537 /* not function graph compares against hits */
538 static int function_stat_cmp(void *p1
, void *p2
)
540 struct ftrace_profile
*a
= p1
;
541 struct ftrace_profile
*b
= p2
;
543 if (a
->counter
< b
->counter
)
545 if (a
->counter
> b
->counter
)
552 static int function_stat_headers(struct seq_file
*m
)
554 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
555 seq_printf(m
, " Function "
558 "--- ---- --- ---\n");
560 seq_printf(m
, " Function Hit\n"
566 static int function_stat_show(struct seq_file
*m
, void *v
)
568 struct ftrace_profile
*rec
= v
;
569 char str
[KSYM_SYMBOL_LEN
];
571 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
572 static struct trace_seq s
;
573 unsigned long long avg
;
574 unsigned long long stddev
;
576 mutex_lock(&ftrace_profile_lock
);
578 /* we raced with function_profile_reset() */
579 if (unlikely(rec
->counter
== 0)) {
584 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
585 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
587 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
590 do_div(avg
, rec
->counter
);
592 /* Sample standard deviation (s^2) */
593 if (rec
->counter
<= 1)
597 * Apply Welford's method:
598 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
600 stddev
= rec
->counter
* rec
->time_squared
-
601 rec
->time
* rec
->time
;
604 * Divide only 1000 for ns^2 -> us^2 conversion.
605 * trace_print_graph_duration will divide 1000 again.
607 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
611 trace_print_graph_duration(rec
->time
, &s
);
612 trace_seq_puts(&s
, " ");
613 trace_print_graph_duration(avg
, &s
);
614 trace_seq_puts(&s
, " ");
615 trace_print_graph_duration(stddev
, &s
);
616 trace_print_seq(m
, &s
);
620 mutex_unlock(&ftrace_profile_lock
);
625 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
627 struct ftrace_profile_page
*pg
;
629 pg
= stat
->pages
= stat
->start
;
632 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
637 memset(stat
->hash
, 0,
638 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
641 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
643 struct ftrace_profile_page
*pg
;
648 /* If we already allocated, do nothing */
652 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
656 #ifdef CONFIG_DYNAMIC_FTRACE
657 functions
= ftrace_update_tot_cnt
;
660 * We do not know the number of functions that exist because
661 * dynamic tracing is what counts them. With past experience
662 * we have around 20K functions. That should be more than enough.
663 * It is highly unlikely we will execute every function in
669 pg
= stat
->start
= stat
->pages
;
671 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
673 for (i
= 1; i
< pages
; i
++) {
674 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
685 unsigned long tmp
= (unsigned long)pg
;
697 static int ftrace_profile_init_cpu(int cpu
)
699 struct ftrace_profile_stat
*stat
;
702 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
705 /* If the profile is already created, simply reset it */
706 ftrace_profile_reset(stat
);
711 * We are profiling all functions, but usually only a few thousand
712 * functions are hit. We'll make a hash of 1024 items.
714 size
= FTRACE_PROFILE_HASH_SIZE
;
716 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
721 /* Preallocate the function profiling pages */
722 if (ftrace_profile_pages_init(stat
) < 0) {
731 static int ftrace_profile_init(void)
736 for_each_possible_cpu(cpu
) {
737 ret
= ftrace_profile_init_cpu(cpu
);
745 /* interrupts must be disabled */
746 static struct ftrace_profile
*
747 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
749 struct ftrace_profile
*rec
;
750 struct hlist_head
*hhd
;
753 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
754 hhd
= &stat
->hash
[key
];
756 if (hlist_empty(hhd
))
759 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
767 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
768 struct ftrace_profile
*rec
)
772 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
773 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
777 * The memory is already allocated, this simply finds a new record to use.
779 static struct ftrace_profile
*
780 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
782 struct ftrace_profile
*rec
= NULL
;
784 /* prevent recursion (from NMIs) */
785 if (atomic_inc_return(&stat
->disabled
) != 1)
789 * Try to find the function again since an NMI
790 * could have added it
792 rec
= ftrace_find_profiled_func(stat
, ip
);
796 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
797 if (!stat
->pages
->next
)
799 stat
->pages
= stat
->pages
->next
;
802 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
804 ftrace_add_profile(stat
, rec
);
807 atomic_dec(&stat
->disabled
);
813 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
814 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
816 struct ftrace_profile_stat
*stat
;
817 struct ftrace_profile
*rec
;
820 if (!ftrace_profile_enabled
)
823 local_irq_save(flags
);
825 stat
= this_cpu_ptr(&ftrace_profile_stats
);
826 if (!stat
->hash
|| !ftrace_profile_enabled
)
829 rec
= ftrace_find_profiled_func(stat
, ip
);
831 rec
= ftrace_profile_alloc(stat
, ip
);
838 local_irq_restore(flags
);
841 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
842 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
844 function_profile_call(trace
->func
, 0, NULL
, NULL
);
848 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
850 struct ftrace_profile_stat
*stat
;
851 unsigned long long calltime
;
852 struct ftrace_profile
*rec
;
855 local_irq_save(flags
);
856 stat
= this_cpu_ptr(&ftrace_profile_stats
);
857 if (!stat
->hash
|| !ftrace_profile_enabled
)
860 /* If the calltime was zero'd ignore it */
861 if (!trace
->calltime
)
864 calltime
= trace
->rettime
- trace
->calltime
;
866 if (!(trace_flags
& TRACE_ITER_GRAPH_TIME
)) {
869 index
= trace
->depth
;
871 /* Append this call time to the parent time to subtract */
873 current
->ret_stack
[index
- 1].subtime
+= calltime
;
875 if (current
->ret_stack
[index
].subtime
< calltime
)
876 calltime
-= current
->ret_stack
[index
].subtime
;
881 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
883 rec
->time
+= calltime
;
884 rec
->time_squared
+= calltime
* calltime
;
888 local_irq_restore(flags
);
891 static int register_ftrace_profiler(void)
893 return register_ftrace_graph(&profile_graph_return
,
894 &profile_graph_entry
);
897 static void unregister_ftrace_profiler(void)
899 unregister_ftrace_graph();
902 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
903 .func
= function_profile_call
,
904 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
905 INIT_REGEX_LOCK(ftrace_profile_ops
)
908 static int register_ftrace_profiler(void)
910 return register_ftrace_function(&ftrace_profile_ops
);
913 static void unregister_ftrace_profiler(void)
915 unregister_ftrace_function(&ftrace_profile_ops
);
917 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
920 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
921 size_t cnt
, loff_t
*ppos
)
926 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
932 mutex_lock(&ftrace_profile_lock
);
933 if (ftrace_profile_enabled
^ val
) {
935 ret
= ftrace_profile_init();
941 ret
= register_ftrace_profiler();
946 ftrace_profile_enabled
= 1;
948 ftrace_profile_enabled
= 0;
950 * unregister_ftrace_profiler calls stop_machine
951 * so this acts like an synchronize_sched.
953 unregister_ftrace_profiler();
957 mutex_unlock(&ftrace_profile_lock
);
965 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
966 size_t cnt
, loff_t
*ppos
)
968 char buf
[64]; /* big enough to hold a number */
971 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
972 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
975 static const struct file_operations ftrace_profile_fops
= {
976 .open
= tracing_open_generic
,
977 .read
= ftrace_profile_read
,
978 .write
= ftrace_profile_write
,
979 .llseek
= default_llseek
,
982 /* used to initialize the real stat files */
983 static struct tracer_stat function_stats __initdata
= {
985 .stat_start
= function_stat_start
,
986 .stat_next
= function_stat_next
,
987 .stat_cmp
= function_stat_cmp
,
988 .stat_headers
= function_stat_headers
,
989 .stat_show
= function_stat_show
992 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
994 struct ftrace_profile_stat
*stat
;
995 struct dentry
*entry
;
1000 for_each_possible_cpu(cpu
) {
1001 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1003 /* allocate enough for function name + cpu number */
1004 name
= kmalloc(32, GFP_KERNEL
);
1007 * The files created are permanent, if something happens
1008 * we still do not free memory.
1011 "Could not allocate stat file for cpu %d\n",
1015 stat
->stat
= function_stats
;
1016 snprintf(name
, 32, "function%d", cpu
);
1017 stat
->stat
.name
= name
;
1018 ret
= register_stat_tracer(&stat
->stat
);
1021 "Could not register function stat for cpu %d\n",
1028 entry
= debugfs_create_file("function_profile_enabled", 0644,
1029 d_tracer
, NULL
, &ftrace_profile_fops
);
1031 pr_warning("Could not create debugfs "
1032 "'function_profile_enabled' entry\n");
1035 #else /* CONFIG_FUNCTION_PROFILER */
1036 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1039 #endif /* CONFIG_FUNCTION_PROFILER */
1041 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1043 #ifdef CONFIG_DYNAMIC_FTRACE
1045 static struct ftrace_ops
*removed_ops
;
1047 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1048 # error Dynamic ftrace depends on MCOUNT_RECORD
1051 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1053 struct ftrace_func_probe
{
1054 struct hlist_node node
;
1055 struct ftrace_probe_ops
*ops
;
1056 unsigned long flags
;
1059 struct list_head free_list
;
1062 struct ftrace_func_entry
{
1063 struct hlist_node hlist
;
1067 struct ftrace_hash
{
1068 unsigned long size_bits
;
1069 struct hlist_head
*buckets
;
1070 unsigned long count
;
1071 struct rcu_head rcu
;
1075 * We make these constant because no one should touch them,
1076 * but they are used as the default "empty hash", to avoid allocating
1077 * it all the time. These are in a read only section such that if
1078 * anyone does try to modify it, it will cause an exception.
1080 static const struct hlist_head empty_buckets
[1];
1081 static const struct ftrace_hash empty_hash
= {
1082 .buckets
= (struct hlist_head
*)empty_buckets
,
1084 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1086 static struct ftrace_ops global_ops
= {
1087 .func
= ftrace_stub
,
1088 .notrace_hash
= EMPTY_HASH
,
1089 .filter_hash
= EMPTY_HASH
,
1090 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
1091 INIT_REGEX_LOCK(global_ops
)
1094 struct ftrace_page
{
1095 struct ftrace_page
*next
;
1096 struct dyn_ftrace
*records
;
1101 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1102 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1104 /* estimate from running different kernels */
1105 #define NR_TO_INIT 10000
1107 static struct ftrace_page
*ftrace_pages_start
;
1108 static struct ftrace_page
*ftrace_pages
;
1110 static bool __always_inline
ftrace_hash_empty(struct ftrace_hash
*hash
)
1112 return !hash
|| !hash
->count
;
1115 static struct ftrace_func_entry
*
1116 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1119 struct ftrace_func_entry
*entry
;
1120 struct hlist_head
*hhd
;
1122 if (ftrace_hash_empty(hash
))
1125 if (hash
->size_bits
> 0)
1126 key
= hash_long(ip
, hash
->size_bits
);
1130 hhd
= &hash
->buckets
[key
];
1132 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1133 if (entry
->ip
== ip
)
1139 static void __add_hash_entry(struct ftrace_hash
*hash
,
1140 struct ftrace_func_entry
*entry
)
1142 struct hlist_head
*hhd
;
1145 if (hash
->size_bits
)
1146 key
= hash_long(entry
->ip
, hash
->size_bits
);
1150 hhd
= &hash
->buckets
[key
];
1151 hlist_add_head(&entry
->hlist
, hhd
);
1155 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1157 struct ftrace_func_entry
*entry
;
1159 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1164 __add_hash_entry(hash
, entry
);
1170 free_hash_entry(struct ftrace_hash
*hash
,
1171 struct ftrace_func_entry
*entry
)
1173 hlist_del(&entry
->hlist
);
1179 remove_hash_entry(struct ftrace_hash
*hash
,
1180 struct ftrace_func_entry
*entry
)
1182 hlist_del(&entry
->hlist
);
1186 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1188 struct hlist_head
*hhd
;
1189 struct hlist_node
*tn
;
1190 struct ftrace_func_entry
*entry
;
1191 int size
= 1 << hash
->size_bits
;
1197 for (i
= 0; i
< size
; i
++) {
1198 hhd
= &hash
->buckets
[i
];
1199 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1200 free_hash_entry(hash
, entry
);
1202 FTRACE_WARN_ON(hash
->count
);
1205 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1207 if (!hash
|| hash
== EMPTY_HASH
)
1209 ftrace_hash_clear(hash
);
1210 kfree(hash
->buckets
);
1214 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1216 struct ftrace_hash
*hash
;
1218 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1219 free_ftrace_hash(hash
);
1222 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1224 if (!hash
|| hash
== EMPTY_HASH
)
1226 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1229 void ftrace_free_filter(struct ftrace_ops
*ops
)
1231 ftrace_ops_init(ops
);
1232 free_ftrace_hash(ops
->filter_hash
);
1233 free_ftrace_hash(ops
->notrace_hash
);
1236 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1238 struct ftrace_hash
*hash
;
1241 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1245 size
= 1 << size_bits
;
1246 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1248 if (!hash
->buckets
) {
1253 hash
->size_bits
= size_bits
;
1258 static struct ftrace_hash
*
1259 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1261 struct ftrace_func_entry
*entry
;
1262 struct ftrace_hash
*new_hash
;
1267 new_hash
= alloc_ftrace_hash(size_bits
);
1272 if (ftrace_hash_empty(hash
))
1275 size
= 1 << hash
->size_bits
;
1276 for (i
= 0; i
< size
; i
++) {
1277 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1278 ret
= add_hash_entry(new_hash
, entry
->ip
);
1284 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1289 free_ftrace_hash(new_hash
);
1294 ftrace_hash_rec_disable(struct ftrace_ops
*ops
, int filter_hash
);
1296 ftrace_hash_rec_enable(struct ftrace_ops
*ops
, int filter_hash
);
1299 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1300 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1302 struct ftrace_func_entry
*entry
;
1303 struct hlist_node
*tn
;
1304 struct hlist_head
*hhd
;
1305 struct ftrace_hash
*old_hash
;
1306 struct ftrace_hash
*new_hash
;
1307 int size
= src
->count
;
1312 * If the new source is empty, just free dst and assign it
1316 new_hash
= EMPTY_HASH
;
1321 * Make the hash size about 1/2 the # found
1323 for (size
/= 2; size
; size
>>= 1)
1326 /* Don't allocate too much */
1327 if (bits
> FTRACE_HASH_MAX_BITS
)
1328 bits
= FTRACE_HASH_MAX_BITS
;
1330 new_hash
= alloc_ftrace_hash(bits
);
1334 size
= 1 << src
->size_bits
;
1335 for (i
= 0; i
< size
; i
++) {
1336 hhd
= &src
->buckets
[i
];
1337 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1338 remove_hash_entry(src
, entry
);
1339 __add_hash_entry(new_hash
, entry
);
1345 * Remove the current set, update the hash and add
1348 ftrace_hash_rec_disable(ops
, enable
);
1351 rcu_assign_pointer(*dst
, new_hash
);
1352 free_ftrace_hash_rcu(old_hash
);
1354 ftrace_hash_rec_enable(ops
, enable
);
1360 * Test the hashes for this ops to see if we want to call
1361 * the ops->func or not.
1363 * It's a match if the ip is in the ops->filter_hash or
1364 * the filter_hash does not exist or is empty,
1366 * the ip is not in the ops->notrace_hash.
1368 * This needs to be called with preemption disabled as
1369 * the hashes are freed with call_rcu_sched().
1372 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1374 struct ftrace_hash
*filter_hash
;
1375 struct ftrace_hash
*notrace_hash
;
1378 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1380 * There's a small race when adding ops that the ftrace handler
1381 * that wants regs, may be called without them. We can not
1382 * allow that handler to be called if regs is NULL.
1384 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1388 filter_hash
= rcu_dereference_raw_notrace(ops
->filter_hash
);
1389 notrace_hash
= rcu_dereference_raw_notrace(ops
->notrace_hash
);
1391 if ((ftrace_hash_empty(filter_hash
) ||
1392 ftrace_lookup_ip(filter_hash
, ip
)) &&
1393 (ftrace_hash_empty(notrace_hash
) ||
1394 !ftrace_lookup_ip(notrace_hash
, ip
)))
1403 * This is a double for. Do not use 'break' to break out of the loop,
1404 * you must use a goto.
1406 #define do_for_each_ftrace_rec(pg, rec) \
1407 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1409 for (_____i = 0; _____i < pg->index; _____i++) { \
1410 rec = &pg->records[_____i];
1412 #define while_for_each_ftrace_rec() \
1417 static int ftrace_cmp_recs(const void *a
, const void *b
)
1419 const struct dyn_ftrace
*key
= a
;
1420 const struct dyn_ftrace
*rec
= b
;
1422 if (key
->flags
< rec
->ip
)
1424 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1429 static unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1431 struct ftrace_page
*pg
;
1432 struct dyn_ftrace
*rec
;
1433 struct dyn_ftrace key
;
1436 key
.flags
= end
; /* overload flags, as it is unsigned long */
1438 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1439 if (end
< pg
->records
[0].ip
||
1440 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1442 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1443 sizeof(struct dyn_ftrace
),
1453 * ftrace_location - return true if the ip giving is a traced location
1454 * @ip: the instruction pointer to check
1456 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1457 * That is, the instruction that is either a NOP or call to
1458 * the function tracer. It checks the ftrace internal tables to
1459 * determine if the address belongs or not.
1461 unsigned long ftrace_location(unsigned long ip
)
1463 return ftrace_location_range(ip
, ip
);
1467 * ftrace_text_reserved - return true if range contains an ftrace location
1468 * @start: start of range to search
1469 * @end: end of range to search (inclusive). @end points to the last byte to check.
1471 * Returns 1 if @start and @end contains a ftrace location.
1472 * That is, the instruction that is either a NOP or call to
1473 * the function tracer. It checks the ftrace internal tables to
1474 * determine if the address belongs or not.
1476 int ftrace_text_reserved(const void *start
, const void *end
)
1480 ret
= ftrace_location_range((unsigned long)start
,
1481 (unsigned long)end
);
1486 /* Test if ops registered to this rec needs regs */
1487 static bool test_rec_ops_needs_regs(struct dyn_ftrace
*rec
)
1489 struct ftrace_ops
*ops
;
1490 bool keep_regs
= false;
1492 for (ops
= ftrace_ops_list
;
1493 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
1494 /* pass rec in as regs to have non-NULL val */
1495 if (ftrace_ops_test(ops
, rec
->ip
, rec
)) {
1496 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1506 static void ftrace_remove_tramp(struct ftrace_ops
*ops
,
1507 struct dyn_ftrace
*rec
)
1509 struct ftrace_func_entry
*entry
;
1511 entry
= ftrace_lookup_ip(ops
->tramp_hash
, rec
->ip
);
1516 * The tramp_hash entry will be removed at time
1520 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1523 static void ftrace_clear_tramps(struct dyn_ftrace
*rec
)
1525 struct ftrace_ops
*op
;
1527 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1528 if (op
->trampolines
)
1529 ftrace_remove_tramp(op
, rec
);
1530 } while_for_each_ftrace_op(op
);
1533 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1537 struct ftrace_hash
*hash
;
1538 struct ftrace_hash
*other_hash
;
1539 struct ftrace_page
*pg
;
1540 struct dyn_ftrace
*rec
;
1544 /* Only update if the ops has been registered */
1545 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1549 * In the filter_hash case:
1550 * If the count is zero, we update all records.
1551 * Otherwise we just update the items in the hash.
1553 * In the notrace_hash case:
1554 * We enable the update in the hash.
1555 * As disabling notrace means enabling the tracing,
1556 * and enabling notrace means disabling, the inc variable
1560 hash
= ops
->filter_hash
;
1561 other_hash
= ops
->notrace_hash
;
1562 if (ftrace_hash_empty(hash
))
1566 hash
= ops
->notrace_hash
;
1567 other_hash
= ops
->filter_hash
;
1569 * If the notrace hash has no items,
1570 * then there's nothing to do.
1572 if (ftrace_hash_empty(hash
))
1576 do_for_each_ftrace_rec(pg
, rec
) {
1577 int in_other_hash
= 0;
1583 * Only the filter_hash affects all records.
1584 * Update if the record is not in the notrace hash.
1586 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1589 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1590 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1593 * If filter_hash is set, we want to match all functions
1594 * that are in the hash but not in the other hash.
1596 * If filter_hash is not set, then we are decrementing.
1597 * That means we match anything that is in the hash
1598 * and also in the other_hash. That is, we need to turn
1599 * off functions in the other hash because they are disabled
1602 if (filter_hash
&& in_hash
&& !in_other_hash
)
1604 else if (!filter_hash
&& in_hash
&&
1605 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1613 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == FTRACE_REF_MAX
))
1617 * If there's only a single callback registered to a
1618 * function, and the ops has a trampoline registered
1619 * for it, then we can call it directly.
1621 if (ftrace_rec_count(rec
) == 1 && ops
->trampoline
) {
1622 rec
->flags
|= FTRACE_FL_TRAMP
;
1626 * If we are adding another function callback
1627 * to this function, and the previous had a
1628 * trampoline used, then we need to go back to
1629 * the default trampoline.
1631 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1633 /* remove trampolines from any ops for this rec */
1634 ftrace_clear_tramps(rec
);
1638 * If any ops wants regs saved for this function
1639 * then all ops will get saved regs.
1641 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1642 rec
->flags
|= FTRACE_FL_REGS
;
1644 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == 0))
1648 if (ops
->trampoline
&& !ftrace_rec_count(rec
))
1649 ftrace_remove_tramp(ops
, rec
);
1652 * If the rec had REGS enabled and the ops that is
1653 * being removed had REGS set, then see if there is
1654 * still any ops for this record that wants regs.
1655 * If not, we can stop recording them.
1657 if (ftrace_rec_count(rec
) > 0 &&
1658 rec
->flags
& FTRACE_FL_REGS
&&
1659 ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1660 if (!test_rec_ops_needs_regs(rec
))
1661 rec
->flags
&= ~FTRACE_FL_REGS
;
1665 * flags will be cleared in ftrace_check_record()
1666 * if rec count is zero.
1670 /* Shortcut, if we handled all records, we are done. */
1671 if (!all
&& count
== hash
->count
)
1673 } while_for_each_ftrace_rec();
1676 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1679 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1682 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1685 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1688 static void print_ip_ins(const char *fmt
, unsigned char *p
)
1692 printk(KERN_CONT
"%s", fmt
);
1694 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1695 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1699 * ftrace_bug - report and shutdown function tracer
1700 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1701 * @ip: The address that failed
1703 * The arch code that enables or disables the function tracing
1704 * can call ftrace_bug() when it has detected a problem in
1705 * modifying the code. @failed should be one of either:
1706 * EFAULT - if the problem happens on reading the @ip address
1707 * EINVAL - if what is read at @ip is not what was expected
1708 * EPERM - if the problem happens on writting to the @ip address
1710 void ftrace_bug(int failed
, unsigned long ip
)
1714 FTRACE_WARN_ON_ONCE(1);
1715 pr_info("ftrace faulted on modifying ");
1719 FTRACE_WARN_ON_ONCE(1);
1720 pr_info("ftrace failed to modify ");
1722 print_ip_ins(" actual: ", (unsigned char *)ip
);
1723 printk(KERN_CONT
"\n");
1726 FTRACE_WARN_ON_ONCE(1);
1727 pr_info("ftrace faulted on writing ");
1731 FTRACE_WARN_ON_ONCE(1);
1732 pr_info("ftrace faulted on unknown error ");
1737 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
1739 unsigned long flag
= 0UL;
1742 * If we are updating calls:
1744 * If the record has a ref count, then we need to enable it
1745 * because someone is using it.
1747 * Otherwise we make sure its disabled.
1749 * If we are disabling calls, then disable all records that
1752 if (enable
&& ftrace_rec_count(rec
))
1753 flag
= FTRACE_FL_ENABLED
;
1756 * If enabling and the REGS flag does not match the REGS_EN, or
1757 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
1758 * this record. Set flags to fail the compare against ENABLED.
1761 if (!(rec
->flags
& FTRACE_FL_REGS
) !=
1762 !(rec
->flags
& FTRACE_FL_REGS_EN
))
1763 flag
|= FTRACE_FL_REGS
;
1765 if (!(rec
->flags
& FTRACE_FL_TRAMP
) !=
1766 !(rec
->flags
& FTRACE_FL_TRAMP_EN
))
1767 flag
|= FTRACE_FL_TRAMP
;
1770 /* If the state of this record hasn't changed, then do nothing */
1771 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
1772 return FTRACE_UPDATE_IGNORE
;
1775 /* Save off if rec is being enabled (for return value) */
1776 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
1779 rec
->flags
|= FTRACE_FL_ENABLED
;
1780 if (flag
& FTRACE_FL_REGS
) {
1781 if (rec
->flags
& FTRACE_FL_REGS
)
1782 rec
->flags
|= FTRACE_FL_REGS_EN
;
1784 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
1786 if (flag
& FTRACE_FL_TRAMP
) {
1787 if (rec
->flags
& FTRACE_FL_TRAMP
)
1788 rec
->flags
|= FTRACE_FL_TRAMP_EN
;
1790 rec
->flags
&= ~FTRACE_FL_TRAMP_EN
;
1795 * If this record is being updated from a nop, then
1796 * return UPDATE_MAKE_CALL.
1798 * return UPDATE_MODIFY_CALL to tell the caller to convert
1799 * from the save regs, to a non-save regs function or
1800 * vice versa, or from a trampoline call.
1802 if (flag
& FTRACE_FL_ENABLED
)
1803 return FTRACE_UPDATE_MAKE_CALL
;
1805 return FTRACE_UPDATE_MODIFY_CALL
;
1809 /* If there's no more users, clear all flags */
1810 if (!ftrace_rec_count(rec
))
1813 /* Just disable the record (keep REGS state) */
1814 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1817 return FTRACE_UPDATE_MAKE_NOP
;
1821 * ftrace_update_record, set a record that now is tracing or not
1822 * @rec: the record to update
1823 * @enable: set to 1 if the record is tracing, zero to force disable
1825 * The records that represent all functions that can be traced need
1826 * to be updated when tracing has been enabled.
1828 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
1830 return ftrace_check_record(rec
, enable
, 1);
1834 * ftrace_test_record, check if the record has been enabled or not
1835 * @rec: the record to test
1836 * @enable: set to 1 to check if enabled, 0 if it is disabled
1838 * The arch code may need to test if a record is already set to
1839 * tracing to determine how to modify the function code that it
1842 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
1844 return ftrace_check_record(rec
, enable
, 0);
1847 static struct ftrace_ops
*
1848 ftrace_find_tramp_ops_curr(struct dyn_ftrace
*rec
)
1850 struct ftrace_ops
*op
;
1852 /* Removed ops need to be tested first */
1853 if (removed_ops
&& removed_ops
->tramp_hash
) {
1854 if (ftrace_lookup_ip(removed_ops
->tramp_hash
, rec
->ip
))
1858 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1859 if (!op
->tramp_hash
)
1862 if (ftrace_lookup_ip(op
->tramp_hash
, rec
->ip
))
1865 } while_for_each_ftrace_op(op
);
1870 static struct ftrace_ops
*
1871 ftrace_find_tramp_ops_new(struct dyn_ftrace
*rec
)
1873 struct ftrace_ops
*op
;
1875 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1876 /* pass rec in as regs to have non-NULL val */
1877 if (ftrace_ops_test(op
, rec
->ip
, rec
))
1879 } while_for_each_ftrace_op(op
);
1885 * ftrace_get_addr_new - Get the call address to set to
1886 * @rec: The ftrace record descriptor
1888 * If the record has the FTRACE_FL_REGS set, that means that it
1889 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
1890 * is not not set, then it wants to convert to the normal callback.
1892 * Returns the address of the trampoline to set to
1894 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
)
1896 struct ftrace_ops
*ops
;
1898 /* Trampolines take precedence over regs */
1899 if (rec
->flags
& FTRACE_FL_TRAMP
) {
1900 ops
= ftrace_find_tramp_ops_new(rec
);
1901 if (FTRACE_WARN_ON(!ops
|| !ops
->trampoline
)) {
1902 pr_warning("Bad trampoline accounting at: %p (%pS)\n",
1903 (void *)rec
->ip
, (void *)rec
->ip
);
1904 /* Ftrace is shutting down, return anything */
1905 return (unsigned long)FTRACE_ADDR
;
1907 return ops
->trampoline
;
1910 if (rec
->flags
& FTRACE_FL_REGS
)
1911 return (unsigned long)FTRACE_REGS_ADDR
;
1913 return (unsigned long)FTRACE_ADDR
;
1917 * ftrace_get_addr_curr - Get the call address that is already there
1918 * @rec: The ftrace record descriptor
1920 * The FTRACE_FL_REGS_EN is set when the record already points to
1921 * a function that saves all the regs. Basically the '_EN' version
1922 * represents the current state of the function.
1924 * Returns the address of the trampoline that is currently being called
1926 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
)
1928 struct ftrace_ops
*ops
;
1930 /* Trampolines take precedence over regs */
1931 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
1932 ops
= ftrace_find_tramp_ops_curr(rec
);
1933 if (FTRACE_WARN_ON(!ops
)) {
1934 pr_warning("Bad trampoline accounting at: %p (%pS)\n",
1935 (void *)rec
->ip
, (void *)rec
->ip
);
1936 /* Ftrace is shutting down, return anything */
1937 return (unsigned long)FTRACE_ADDR
;
1939 return ops
->trampoline
;
1942 if (rec
->flags
& FTRACE_FL_REGS_EN
)
1943 return (unsigned long)FTRACE_REGS_ADDR
;
1945 return (unsigned long)FTRACE_ADDR
;
1949 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
1951 unsigned long ftrace_old_addr
;
1952 unsigned long ftrace_addr
;
1955 ftrace_addr
= ftrace_get_addr_new(rec
);
1957 /* This needs to be done before we call ftrace_update_record */
1958 ftrace_old_addr
= ftrace_get_addr_curr(rec
);
1960 ret
= ftrace_update_record(rec
, enable
);
1963 case FTRACE_UPDATE_IGNORE
:
1966 case FTRACE_UPDATE_MAKE_CALL
:
1967 return ftrace_make_call(rec
, ftrace_addr
);
1969 case FTRACE_UPDATE_MAKE_NOP
:
1970 return ftrace_make_nop(NULL
, rec
, ftrace_addr
);
1972 case FTRACE_UPDATE_MODIFY_CALL
:
1973 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
1976 return -1; /* unknow ftrace bug */
1979 void __weak
ftrace_replace_code(int enable
)
1981 struct dyn_ftrace
*rec
;
1982 struct ftrace_page
*pg
;
1985 if (unlikely(ftrace_disabled
))
1988 do_for_each_ftrace_rec(pg
, rec
) {
1989 failed
= __ftrace_replace_code(rec
, enable
);
1991 ftrace_bug(failed
, rec
->ip
);
1992 /* Stop processing */
1995 } while_for_each_ftrace_rec();
1998 struct ftrace_rec_iter
{
1999 struct ftrace_page
*pg
;
2004 * ftrace_rec_iter_start, start up iterating over traced functions
2006 * Returns an iterator handle that is used to iterate over all
2007 * the records that represent address locations where functions
2010 * May return NULL if no records are available.
2012 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
2015 * We only use a single iterator.
2016 * Protected by the ftrace_lock mutex.
2018 static struct ftrace_rec_iter ftrace_rec_iter
;
2019 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
2021 iter
->pg
= ftrace_pages_start
;
2024 /* Could have empty pages */
2025 while (iter
->pg
&& !iter
->pg
->index
)
2026 iter
->pg
= iter
->pg
->next
;
2035 * ftrace_rec_iter_next, get the next record to process.
2036 * @iter: The handle to the iterator.
2038 * Returns the next iterator after the given iterator @iter.
2040 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
2044 if (iter
->index
>= iter
->pg
->index
) {
2045 iter
->pg
= iter
->pg
->next
;
2048 /* Could have empty pages */
2049 while (iter
->pg
&& !iter
->pg
->index
)
2050 iter
->pg
= iter
->pg
->next
;
2060 * ftrace_rec_iter_record, get the record at the iterator location
2061 * @iter: The current iterator location
2063 * Returns the record that the current @iter is at.
2065 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
2067 return &iter
->pg
->records
[iter
->index
];
2071 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
2078 if (unlikely(ftrace_disabled
))
2081 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
2083 ftrace_bug(ret
, ip
);
2090 * archs can override this function if they must do something
2091 * before the modifying code is performed.
2093 int __weak
ftrace_arch_code_modify_prepare(void)
2099 * archs can override this function if they must do something
2100 * after the modifying code is performed.
2102 int __weak
ftrace_arch_code_modify_post_process(void)
2107 void ftrace_modify_all_code(int command
)
2109 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
2113 * If the ftrace_caller calls a ftrace_ops func directly,
2114 * we need to make sure that it only traces functions it
2115 * expects to trace. When doing the switch of functions,
2116 * we need to update to the ftrace_ops_list_func first
2117 * before the transition between old and new calls are set,
2118 * as the ftrace_ops_list_func will check the ops hashes
2119 * to make sure the ops are having the right functions
2123 err
= ftrace_update_ftrace_func(ftrace_ops_list_func
);
2124 if (FTRACE_WARN_ON(err
))
2128 if (command
& FTRACE_UPDATE_CALLS
)
2129 ftrace_replace_code(1);
2130 else if (command
& FTRACE_DISABLE_CALLS
)
2131 ftrace_replace_code(0);
2133 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
) {
2134 function_trace_op
= set_function_trace_op
;
2136 /* If irqs are disabled, we are in stop machine */
2137 if (!irqs_disabled())
2138 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2139 err
= ftrace_update_ftrace_func(ftrace_trace_function
);
2140 if (FTRACE_WARN_ON(err
))
2144 if (command
& FTRACE_START_FUNC_RET
)
2145 err
= ftrace_enable_ftrace_graph_caller();
2146 else if (command
& FTRACE_STOP_FUNC_RET
)
2147 err
= ftrace_disable_ftrace_graph_caller();
2148 FTRACE_WARN_ON(err
);
2151 static int __ftrace_modify_code(void *data
)
2153 int *command
= data
;
2155 ftrace_modify_all_code(*command
);
2161 * ftrace_run_stop_machine, go back to the stop machine method
2162 * @command: The command to tell ftrace what to do
2164 * If an arch needs to fall back to the stop machine method, the
2165 * it can call this function.
2167 void ftrace_run_stop_machine(int command
)
2169 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2173 * arch_ftrace_update_code, modify the code to trace or not trace
2174 * @command: The command that needs to be done
2176 * Archs can override this function if it does not need to
2177 * run stop_machine() to modify code.
2179 void __weak
arch_ftrace_update_code(int command
)
2181 ftrace_run_stop_machine(command
);
2184 static int ftrace_save_ops_tramp_hash(struct ftrace_ops
*ops
)
2186 struct ftrace_page
*pg
;
2187 struct dyn_ftrace
*rec
;
2191 size
= ops
->trampolines
;
2194 * Make the hash size about 1/2 the # found
2196 for (size
/= 2; size
; size
>>= 1)
2199 ops
->tramp_hash
= alloc_ftrace_hash(bits
);
2201 * TODO: a failed allocation is going to screw up
2202 * the accounting of what needs to be modified
2203 * and not. For now, we kill ftrace if we fail
2204 * to allocate here. But there are ways around this,
2205 * but that will take a little more work.
2207 if (!ops
->tramp_hash
)
2210 do_for_each_ftrace_rec(pg
, rec
) {
2211 if (ftrace_rec_count(rec
) == 1 &&
2212 ftrace_ops_test(ops
, rec
->ip
, rec
)) {
2214 /* This record had better have a trampoline */
2215 if (FTRACE_WARN_ON(!(rec
->flags
& FTRACE_FL_TRAMP_EN
)))
2218 ret
= add_hash_entry(ops
->tramp_hash
, rec
->ip
);
2222 } while_for_each_ftrace_rec();
2227 static int ftrace_save_tramp_hashes(void)
2229 struct ftrace_ops
*op
;
2233 * Now that any trampoline is being used, we need to save the
2234 * hashes for the ops that have them. This allows the mapping
2235 * back from the record to the ops that has the trampoline to
2236 * know what code is being replaced. Modifying code must always
2237 * verify what it is changing.
2239 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2241 /* The tramp_hash is recreated each time. */
2242 free_ftrace_hash(op
->tramp_hash
);
2243 op
->tramp_hash
= NULL
;
2245 if (op
->trampolines
) {
2246 ret
= ftrace_save_ops_tramp_hash(op
);
2251 } while_for_each_ftrace_op(op
);
2256 static void ftrace_run_update_code(int command
)
2260 ret
= ftrace_arch_code_modify_prepare();
2261 FTRACE_WARN_ON(ret
);
2265 * Do not call function tracer while we update the code.
2266 * We are in stop machine.
2268 function_trace_stop
++;
2271 * By default we use stop_machine() to modify the code.
2272 * But archs can do what ever they want as long as it
2273 * is safe. The stop_machine() is the safest, but also
2274 * produces the most overhead.
2276 arch_ftrace_update_code(command
);
2278 function_trace_stop
--;
2280 ret
= ftrace_arch_code_modify_post_process();
2281 FTRACE_WARN_ON(ret
);
2283 ret
= ftrace_save_tramp_hashes();
2284 FTRACE_WARN_ON(ret
);
2287 static ftrace_func_t saved_ftrace_func
;
2288 static int ftrace_start_up
;
2290 static void control_ops_free(struct ftrace_ops
*ops
)
2292 free_percpu(ops
->disabled
);
2295 static void ftrace_startup_enable(int command
)
2297 if (saved_ftrace_func
!= ftrace_trace_function
) {
2298 saved_ftrace_func
= ftrace_trace_function
;
2299 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2302 if (!command
|| !ftrace_enabled
)
2305 ftrace_run_update_code(command
);
2308 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2312 if (unlikely(ftrace_disabled
))
2315 ret
= __register_ftrace_function(ops
);
2320 command
|= FTRACE_UPDATE_CALLS
;
2322 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
2324 ftrace_hash_rec_enable(ops
, 1);
2326 ftrace_startup_enable(command
);
2331 static int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2335 if (unlikely(ftrace_disabled
))
2338 ret
= __unregister_ftrace_function(ops
);
2344 * Just warn in case of unbalance, no need to kill ftrace, it's not
2345 * critical but the ftrace_call callers may be never nopped again after
2346 * further ftrace uses.
2348 WARN_ON_ONCE(ftrace_start_up
< 0);
2350 ftrace_hash_rec_disable(ops
, 1);
2352 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2354 command
|= FTRACE_UPDATE_CALLS
;
2356 if (saved_ftrace_func
!= ftrace_trace_function
) {
2357 saved_ftrace_func
= ftrace_trace_function
;
2358 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2361 if (!command
|| !ftrace_enabled
) {
2363 * If these are control ops, they still need their
2364 * per_cpu field freed. Since, function tracing is
2365 * not currently active, we can just free them
2366 * without synchronizing all CPUs.
2368 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
)
2369 control_ops_free(ops
);
2374 * If the ops uses a trampoline, then it needs to be
2375 * tested first on update.
2379 ftrace_run_update_code(command
);
2384 * Dynamic ops may be freed, we must make sure that all
2385 * callers are done before leaving this function.
2386 * The same goes for freeing the per_cpu data of the control
2389 * Again, normal synchronize_sched() is not good enough.
2390 * We need to do a hard force of sched synchronization.
2391 * This is because we use preempt_disable() to do RCU, but
2392 * the function tracers can be called where RCU is not watching
2393 * (like before user_exit()). We can not rely on the RCU
2394 * infrastructure to do the synchronization, thus we must do it
2397 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_CONTROL
)) {
2398 schedule_on_each_cpu(ftrace_sync
);
2400 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
)
2401 control_ops_free(ops
);
2407 static void ftrace_startup_sysctl(void)
2409 if (unlikely(ftrace_disabled
))
2412 /* Force update next time */
2413 saved_ftrace_func
= NULL
;
2414 /* ftrace_start_up is true if we want ftrace running */
2415 if (ftrace_start_up
)
2416 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
2419 static void ftrace_shutdown_sysctl(void)
2421 if (unlikely(ftrace_disabled
))
2424 /* ftrace_start_up is true if ftrace is running */
2425 if (ftrace_start_up
)
2426 ftrace_run_update_code(FTRACE_DISABLE_CALLS
);
2429 static cycle_t ftrace_update_time
;
2430 unsigned long ftrace_update_tot_cnt
;
2432 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2435 * Filter_hash being empty will default to trace module.
2436 * But notrace hash requires a test of individual module functions.
2438 return ftrace_hash_empty(ops
->filter_hash
) &&
2439 ftrace_hash_empty(ops
->notrace_hash
);
2443 * Check if the current ops references the record.
2445 * If the ops traces all functions, then it was already accounted for.
2446 * If the ops does not trace the current record function, skip it.
2447 * If the ops ignores the function via notrace filter, skip it.
2450 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2452 /* If ops isn't enabled, ignore it */
2453 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2456 /* If ops traces all mods, we already accounted for it */
2457 if (ops_traces_mod(ops
))
2460 /* The function must be in the filter */
2461 if (!ftrace_hash_empty(ops
->filter_hash
) &&
2462 !ftrace_lookup_ip(ops
->filter_hash
, rec
->ip
))
2465 /* If in notrace hash, we ignore it too */
2466 if (ftrace_lookup_ip(ops
->notrace_hash
, rec
->ip
))
2472 static int referenced_filters(struct dyn_ftrace
*rec
)
2474 struct ftrace_ops
*ops
;
2477 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2478 if (ops_references_rec(ops
, rec
))
2485 static int ftrace_update_code(struct module
*mod
, struct ftrace_page
*new_pgs
)
2487 struct ftrace_page
*pg
;
2488 struct dyn_ftrace
*p
;
2489 cycle_t start
, stop
;
2490 unsigned long update_cnt
= 0;
2491 unsigned long ref
= 0;
2496 * When adding a module, we need to check if tracers are
2497 * currently enabled and if they are set to trace all functions.
2498 * If they are, we need to enable the module functions as well
2499 * as update the reference counts for those function records.
2502 struct ftrace_ops
*ops
;
2504 for (ops
= ftrace_ops_list
;
2505 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2506 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
2507 if (ops_traces_mod(ops
))
2515 start
= ftrace_now(raw_smp_processor_id());
2517 for (pg
= new_pgs
; pg
; pg
= pg
->next
) {
2519 for (i
= 0; i
< pg
->index
; i
++) {
2522 /* If something went wrong, bail without enabling anything */
2523 if (unlikely(ftrace_disabled
))
2526 p
= &pg
->records
[i
];
2528 cnt
+= referenced_filters(p
);
2532 * Do the initial record conversion from mcount jump
2533 * to the NOP instructions.
2535 if (!ftrace_code_disable(mod
, p
))
2541 * If the tracing is enabled, go ahead and enable the record.
2543 * The reason not to enable the record immediatelly is the
2544 * inherent check of ftrace_make_nop/ftrace_make_call for
2545 * correct previous instructions. Making first the NOP
2546 * conversion puts the module to the correct state, thus
2547 * passing the ftrace_make_call check.
2549 if (ftrace_start_up
&& cnt
) {
2550 int failed
= __ftrace_replace_code(p
, 1);
2552 ftrace_bug(failed
, p
->ip
);
2557 stop
= ftrace_now(raw_smp_processor_id());
2558 ftrace_update_time
= stop
- start
;
2559 ftrace_update_tot_cnt
+= update_cnt
;
2564 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2569 if (WARN_ON(!count
))
2572 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2575 * We want to fill as much as possible. No more than a page
2578 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2582 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2585 /* if we can't allocate this size, try something smaller */
2592 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2601 static struct ftrace_page
*
2602 ftrace_allocate_pages(unsigned long num_to_init
)
2604 struct ftrace_page
*start_pg
;
2605 struct ftrace_page
*pg
;
2612 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2617 * Try to allocate as much as possible in one continues
2618 * location that fills in all of the space. We want to
2619 * waste as little space as possible.
2622 cnt
= ftrace_allocate_records(pg
, num_to_init
);
2630 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2642 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
2643 free_pages((unsigned long)pg
->records
, order
);
2644 start_pg
= pg
->next
;
2648 pr_info("ftrace: FAILED to allocate memory for functions\n");
2652 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2654 struct ftrace_iterator
{
2657 struct ftrace_page
*pg
;
2658 struct dyn_ftrace
*func
;
2659 struct ftrace_func_probe
*probe
;
2660 struct trace_parser parser
;
2661 struct ftrace_hash
*hash
;
2662 struct ftrace_ops
*ops
;
2669 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
2671 struct ftrace_iterator
*iter
= m
->private;
2672 struct hlist_node
*hnd
= NULL
;
2673 struct hlist_head
*hhd
;
2679 hnd
= &iter
->probe
->node
;
2681 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
2684 hhd
= &ftrace_func_hash
[iter
->hidx
];
2686 if (hlist_empty(hhd
)) {
2702 if (WARN_ON_ONCE(!hnd
))
2705 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
2710 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
2712 struct ftrace_iterator
*iter
= m
->private;
2716 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
2719 if (iter
->func_pos
> *pos
)
2723 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
2724 p
= t_hash_next(m
, &l
);
2731 /* Only set this if we have an item */
2732 iter
->flags
|= FTRACE_ITER_HASH
;
2738 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
2740 struct ftrace_func_probe
*rec
;
2743 if (WARN_ON_ONCE(!rec
))
2746 if (rec
->ops
->print
)
2747 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
2749 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
2752 seq_printf(m
, ":%p", rec
->data
);
2759 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2761 struct ftrace_iterator
*iter
= m
->private;
2762 struct ftrace_ops
*ops
= iter
->ops
;
2763 struct dyn_ftrace
*rec
= NULL
;
2765 if (unlikely(ftrace_disabled
))
2768 if (iter
->flags
& FTRACE_ITER_HASH
)
2769 return t_hash_next(m
, pos
);
2772 iter
->pos
= iter
->func_pos
= *pos
;
2774 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
2775 return t_hash_start(m
, pos
);
2778 if (iter
->idx
>= iter
->pg
->index
) {
2779 if (iter
->pg
->next
) {
2780 iter
->pg
= iter
->pg
->next
;
2785 rec
= &iter
->pg
->records
[iter
->idx
++];
2786 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
2787 !(ftrace_lookup_ip(ops
->filter_hash
, rec
->ip
))) ||
2789 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
2790 !ftrace_lookup_ip(ops
->notrace_hash
, rec
->ip
)) ||
2792 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
2793 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
2801 return t_hash_start(m
, pos
);
2808 static void reset_iter_read(struct ftrace_iterator
*iter
)
2812 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
2815 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2817 struct ftrace_iterator
*iter
= m
->private;
2818 struct ftrace_ops
*ops
= iter
->ops
;
2822 mutex_lock(&ftrace_lock
);
2824 if (unlikely(ftrace_disabled
))
2828 * If an lseek was done, then reset and start from beginning.
2830 if (*pos
< iter
->pos
)
2831 reset_iter_read(iter
);
2834 * For set_ftrace_filter reading, if we have the filter
2835 * off, we can short cut and just print out that all
2836 * functions are enabled.
2838 if (iter
->flags
& FTRACE_ITER_FILTER
&&
2839 ftrace_hash_empty(ops
->filter_hash
)) {
2841 return t_hash_start(m
, pos
);
2842 iter
->flags
|= FTRACE_ITER_PRINTALL
;
2843 /* reset in case of seek/pread */
2844 iter
->flags
&= ~FTRACE_ITER_HASH
;
2848 if (iter
->flags
& FTRACE_ITER_HASH
)
2849 return t_hash_start(m
, pos
);
2852 * Unfortunately, we need to restart at ftrace_pages_start
2853 * every time we let go of the ftrace_mutex. This is because
2854 * those pointers can change without the lock.
2856 iter
->pg
= ftrace_pages_start
;
2858 for (l
= 0; l
<= *pos
; ) {
2859 p
= t_next(m
, p
, &l
);
2865 return t_hash_start(m
, pos
);
2870 static void t_stop(struct seq_file
*m
, void *p
)
2872 mutex_unlock(&ftrace_lock
);
2875 static int t_show(struct seq_file
*m
, void *v
)
2877 struct ftrace_iterator
*iter
= m
->private;
2878 struct dyn_ftrace
*rec
;
2880 if (iter
->flags
& FTRACE_ITER_HASH
)
2881 return t_hash_show(m
, iter
);
2883 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
2884 seq_printf(m
, "#### all functions enabled ####\n");
2893 seq_printf(m
, "%ps", (void *)rec
->ip
);
2894 if (iter
->flags
& FTRACE_ITER_ENABLED
) {
2895 seq_printf(m
, " (%ld)%s",
2896 ftrace_rec_count(rec
),
2897 rec
->flags
& FTRACE_FL_REGS
? " R" : " ");
2898 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2899 struct ftrace_ops
*ops
;
2901 ops
= ftrace_find_tramp_ops_curr(rec
);
2902 if (ops
&& ops
->trampoline
)
2903 seq_printf(m
, "\ttramp: %pS",
2904 (void *)ops
->trampoline
);
2906 seq_printf(m
, "\ttramp: ERROR!");
2910 seq_printf(m
, "\n");
2915 static const struct seq_operations show_ftrace_seq_ops
= {
2923 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
2925 struct ftrace_iterator
*iter
;
2927 if (unlikely(ftrace_disabled
))
2930 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2932 iter
->pg
= ftrace_pages_start
;
2933 iter
->ops
= &global_ops
;
2936 return iter
? 0 : -ENOMEM
;
2940 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
2942 struct ftrace_iterator
*iter
;
2944 if (unlikely(ftrace_disabled
))
2947 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2949 iter
->pg
= ftrace_pages_start
;
2950 iter
->flags
= FTRACE_ITER_ENABLED
;
2951 iter
->ops
= &global_ops
;
2954 return iter
? 0 : -ENOMEM
;
2957 static void ftrace_filter_reset(struct ftrace_hash
*hash
)
2959 mutex_lock(&ftrace_lock
);
2960 ftrace_hash_clear(hash
);
2961 mutex_unlock(&ftrace_lock
);
2965 * ftrace_regex_open - initialize function tracer filter files
2966 * @ops: The ftrace_ops that hold the hash filters
2967 * @flag: The type of filter to process
2968 * @inode: The inode, usually passed in to your open routine
2969 * @file: The file, usually passed in to your open routine
2971 * ftrace_regex_open() initializes the filter files for the
2972 * @ops. Depending on @flag it may process the filter hash or
2973 * the notrace hash of @ops. With this called from the open
2974 * routine, you can use ftrace_filter_write() for the write
2975 * routine if @flag has FTRACE_ITER_FILTER set, or
2976 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2977 * tracing_lseek() should be used as the lseek routine, and
2978 * release must call ftrace_regex_release().
2981 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
2982 struct inode
*inode
, struct file
*file
)
2984 struct ftrace_iterator
*iter
;
2985 struct ftrace_hash
*hash
;
2988 ftrace_ops_init(ops
);
2990 if (unlikely(ftrace_disabled
))
2993 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2997 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
3005 mutex_lock(&ops
->regex_lock
);
3007 if (flag
& FTRACE_ITER_NOTRACE
)
3008 hash
= ops
->notrace_hash
;
3010 hash
= ops
->filter_hash
;
3012 if (file
->f_mode
& FMODE_WRITE
) {
3013 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
3015 if (file
->f_flags
& O_TRUNC
)
3016 iter
->hash
= alloc_ftrace_hash(size_bits
);
3018 iter
->hash
= alloc_and_copy_ftrace_hash(size_bits
, hash
);
3021 trace_parser_put(&iter
->parser
);
3028 if (file
->f_mode
& FMODE_READ
) {
3029 iter
->pg
= ftrace_pages_start
;
3031 ret
= seq_open(file
, &show_ftrace_seq_ops
);
3033 struct seq_file
*m
= file
->private_data
;
3037 free_ftrace_hash(iter
->hash
);
3038 trace_parser_put(&iter
->parser
);
3042 file
->private_data
= iter
;
3045 mutex_unlock(&ops
->regex_lock
);
3051 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
3053 struct ftrace_ops
*ops
= inode
->i_private
;
3055 return ftrace_regex_open(ops
,
3056 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
3061 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
3063 struct ftrace_ops
*ops
= inode
->i_private
;
3065 return ftrace_regex_open(ops
, FTRACE_ITER_NOTRACE
,
3069 static int ftrace_match(char *str
, char *regex
, int len
, int type
)
3076 if (strcmp(str
, regex
) == 0)
3079 case MATCH_FRONT_ONLY
:
3080 if (strncmp(str
, regex
, len
) == 0)
3083 case MATCH_MIDDLE_ONLY
:
3084 if (strstr(str
, regex
))
3087 case MATCH_END_ONLY
:
3089 if (slen
>= len
&& memcmp(str
+ slen
- len
, regex
, len
) == 0)
3098 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int not)
3100 struct ftrace_func_entry
*entry
;
3103 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
3105 /* Do nothing if it doesn't exist */
3109 free_hash_entry(hash
, entry
);
3111 /* Do nothing if it exists */
3115 ret
= add_hash_entry(hash
, rec
->ip
);
3121 ftrace_match_record(struct dyn_ftrace
*rec
, char *mod
,
3122 char *regex
, int len
, int type
)
3124 char str
[KSYM_SYMBOL_LEN
];
3127 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
3130 /* module lookup requires matching the module */
3131 if (!modname
|| strcmp(modname
, mod
))
3134 /* blank search means to match all funcs in the mod */
3139 return ftrace_match(str
, regex
, len
, type
);
3143 match_records(struct ftrace_hash
*hash
, char *buff
,
3144 int len
, char *mod
, int not)
3146 unsigned search_len
= 0;
3147 struct ftrace_page
*pg
;
3148 struct dyn_ftrace
*rec
;
3149 int type
= MATCH_FULL
;
3150 char *search
= buff
;
3155 type
= filter_parse_regex(buff
, len
, &search
, ¬);
3156 search_len
= strlen(search
);
3159 mutex_lock(&ftrace_lock
);
3161 if (unlikely(ftrace_disabled
))
3164 do_for_each_ftrace_rec(pg
, rec
) {
3165 if (ftrace_match_record(rec
, mod
, search
, search_len
, type
)) {
3166 ret
= enter_record(hash
, rec
, not);
3173 } while_for_each_ftrace_rec();
3175 mutex_unlock(&ftrace_lock
);
3181 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
3183 return match_records(hash
, buff
, len
, NULL
, 0);
3187 ftrace_match_module_records(struct ftrace_hash
*hash
, char *buff
, char *mod
)
3191 /* blank or '*' mean the same */
3192 if (strcmp(buff
, "*") == 0)
3195 /* handle the case of 'dont filter this module' */
3196 if (strcmp(buff
, "!") == 0 || strcmp(buff
, "!*") == 0) {
3201 return match_records(hash
, buff
, strlen(buff
), mod
, not);
3205 * We register the module command as a template to show others how
3206 * to register the a command as well.
3210 ftrace_mod_callback(struct ftrace_hash
*hash
,
3211 char *func
, char *cmd
, char *param
, int enable
)
3217 * cmd == 'mod' because we only registered this func
3218 * for the 'mod' ftrace_func_command.
3219 * But if you register one func with multiple commands,
3220 * you can tell which command was used by the cmd
3224 /* we must have a module name */
3228 mod
= strsep(¶m
, ":");
3232 ret
= ftrace_match_module_records(hash
, func
, mod
);
3241 static struct ftrace_func_command ftrace_mod_cmd
= {
3243 .func
= ftrace_mod_callback
,
3246 static int __init
ftrace_mod_cmd_init(void)
3248 return register_ftrace_command(&ftrace_mod_cmd
);
3250 core_initcall(ftrace_mod_cmd_init
);
3252 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
3253 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3255 struct ftrace_func_probe
*entry
;
3256 struct hlist_head
*hhd
;
3259 key
= hash_long(ip
, FTRACE_HASH_BITS
);
3261 hhd
= &ftrace_func_hash
[key
];
3263 if (hlist_empty(hhd
))
3267 * Disable preemption for these calls to prevent a RCU grace
3268 * period. This syncs the hash iteration and freeing of items
3269 * on the hash. rcu_read_lock is too dangerous here.
3271 preempt_disable_notrace();
3272 hlist_for_each_entry_rcu_notrace(entry
, hhd
, node
) {
3273 if (entry
->ip
== ip
)
3274 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
3276 preempt_enable_notrace();
3279 static struct ftrace_ops trace_probe_ops __read_mostly
=
3281 .func
= function_trace_probe_call
,
3282 .flags
= FTRACE_OPS_FL_INITIALIZED
,
3283 INIT_REGEX_LOCK(trace_probe_ops
)
3286 static int ftrace_probe_registered
;
3288 static void __enable_ftrace_function_probe(void)
3293 if (ftrace_probe_registered
) {
3294 /* still need to update the function call sites */
3296 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3300 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3301 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3305 /* Nothing registered? */
3306 if (i
== FTRACE_FUNC_HASHSIZE
)
3309 ret
= ftrace_startup(&trace_probe_ops
, 0);
3311 ftrace_probe_registered
= 1;
3314 static void __disable_ftrace_function_probe(void)
3318 if (!ftrace_probe_registered
)
3321 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3322 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3327 /* no more funcs left */
3328 ftrace_shutdown(&trace_probe_ops
, 0);
3330 ftrace_probe_registered
= 0;
3334 static void ftrace_free_entry(struct ftrace_func_probe
*entry
)
3336 if (entry
->ops
->free
)
3337 entry
->ops
->free(entry
->ops
, entry
->ip
, &entry
->data
);
3342 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3345 struct ftrace_func_probe
*entry
;
3346 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.filter_hash
;
3347 struct ftrace_hash
*hash
;
3348 struct ftrace_page
*pg
;
3349 struct dyn_ftrace
*rec
;
3356 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3357 len
= strlen(search
);
3359 /* we do not support '!' for function probes */
3363 mutex_lock(&trace_probe_ops
.regex_lock
);
3365 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3371 if (unlikely(ftrace_disabled
)) {
3376 mutex_lock(&ftrace_lock
);
3378 do_for_each_ftrace_rec(pg
, rec
) {
3380 if (!ftrace_match_record(rec
, NULL
, search
, len
, type
))
3383 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3385 /* If we did not process any, then return error */
3396 * The caller might want to do something special
3397 * for each function we find. We call the callback
3398 * to give the caller an opportunity to do so.
3401 if (ops
->init(ops
, rec
->ip
, &entry
->data
) < 0) {
3402 /* caller does not like this func */
3408 ret
= enter_record(hash
, rec
, 0);
3416 entry
->ip
= rec
->ip
;
3418 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3419 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3421 } while_for_each_ftrace_rec();
3423 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3427 __enable_ftrace_function_probe();
3430 mutex_unlock(&ftrace_lock
);
3432 mutex_unlock(&trace_probe_ops
.regex_lock
);
3433 free_ftrace_hash(hash
);
3439 PROBE_TEST_FUNC
= 1,
3444 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3445 void *data
, int flags
)
3447 struct ftrace_func_entry
*rec_entry
;
3448 struct ftrace_func_probe
*entry
;
3449 struct ftrace_func_probe
*p
;
3450 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.filter_hash
;
3451 struct list_head free_list
;
3452 struct ftrace_hash
*hash
;
3453 struct hlist_node
*tmp
;
3454 char str
[KSYM_SYMBOL_LEN
];
3455 int type
= MATCH_FULL
;
3459 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3464 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3465 len
= strlen(search
);
3467 /* we do not support '!' for function probes */
3472 mutex_lock(&trace_probe_ops
.regex_lock
);
3474 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3476 /* Hmm, should report this somehow */
3479 INIT_LIST_HEAD(&free_list
);
3481 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3482 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3484 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3486 /* break up if statements for readability */
3487 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3490 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3493 /* do this last, since it is the most expensive */
3495 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3497 if (!ftrace_match(str
, glob
, len
, type
))
3501 rec_entry
= ftrace_lookup_ip(hash
, entry
->ip
);
3502 /* It is possible more than one entry had this ip */
3504 free_hash_entry(hash
, rec_entry
);
3506 hlist_del_rcu(&entry
->node
);
3507 list_add(&entry
->free_list
, &free_list
);
3510 mutex_lock(&ftrace_lock
);
3511 __disable_ftrace_function_probe();
3513 * Remove after the disable is called. Otherwise, if the last
3514 * probe is removed, a null hash means *all enabled*.
3516 ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3517 synchronize_sched();
3518 list_for_each_entry_safe(entry
, p
, &free_list
, free_list
) {
3519 list_del(&entry
->free_list
);
3520 ftrace_free_entry(entry
);
3522 mutex_unlock(&ftrace_lock
);
3525 mutex_unlock(&trace_probe_ops
.regex_lock
);
3526 free_ftrace_hash(hash
);
3530 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3533 __unregister_ftrace_function_probe(glob
, ops
, data
,
3534 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3538 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3540 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3543 void unregister_ftrace_function_probe_all(char *glob
)
3545 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3548 static LIST_HEAD(ftrace_commands
);
3549 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3552 * Currently we only register ftrace commands from __init, so mark this
3555 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
3557 struct ftrace_func_command
*p
;
3560 mutex_lock(&ftrace_cmd_mutex
);
3561 list_for_each_entry(p
, &ftrace_commands
, list
) {
3562 if (strcmp(cmd
->name
, p
->name
) == 0) {
3567 list_add(&cmd
->list
, &ftrace_commands
);
3569 mutex_unlock(&ftrace_cmd_mutex
);
3575 * Currently we only unregister ftrace commands from __init, so mark
3578 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
3580 struct ftrace_func_command
*p
, *n
;
3583 mutex_lock(&ftrace_cmd_mutex
);
3584 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
3585 if (strcmp(cmd
->name
, p
->name
) == 0) {
3587 list_del_init(&p
->list
);
3592 mutex_unlock(&ftrace_cmd_mutex
);
3597 static int ftrace_process_regex(struct ftrace_hash
*hash
,
3598 char *buff
, int len
, int enable
)
3600 char *func
, *command
, *next
= buff
;
3601 struct ftrace_func_command
*p
;
3604 func
= strsep(&next
, ":");
3607 ret
= ftrace_match_records(hash
, func
, len
);
3617 command
= strsep(&next
, ":");
3619 mutex_lock(&ftrace_cmd_mutex
);
3620 list_for_each_entry(p
, &ftrace_commands
, list
) {
3621 if (strcmp(p
->name
, command
) == 0) {
3622 ret
= p
->func(hash
, func
, command
, next
, enable
);
3627 mutex_unlock(&ftrace_cmd_mutex
);
3633 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
3634 size_t cnt
, loff_t
*ppos
, int enable
)
3636 struct ftrace_iterator
*iter
;
3637 struct trace_parser
*parser
;
3643 if (file
->f_mode
& FMODE_READ
) {
3644 struct seq_file
*m
= file
->private_data
;
3647 iter
= file
->private_data
;
3649 if (unlikely(ftrace_disabled
))
3652 /* iter->hash is a local copy, so we don't need regex_lock */
3654 parser
= &iter
->parser
;
3655 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
3657 if (read
>= 0 && trace_parser_loaded(parser
) &&
3658 !trace_parser_cont(parser
)) {
3659 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
3660 parser
->idx
, enable
);
3661 trace_parser_clear(parser
);
3672 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
3673 size_t cnt
, loff_t
*ppos
)
3675 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
3679 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
3680 size_t cnt
, loff_t
*ppos
)
3682 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
3686 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
3688 struct ftrace_func_entry
*entry
;
3690 if (!ftrace_location(ip
))
3694 entry
= ftrace_lookup_ip(hash
, ip
);
3697 free_hash_entry(hash
, entry
);
3701 return add_hash_entry(hash
, ip
);
3704 static void ftrace_ops_update_code(struct ftrace_ops
*ops
)
3706 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
&& ftrace_enabled
)
3707 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3711 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3712 unsigned long ip
, int remove
, int reset
, int enable
)
3714 struct ftrace_hash
**orig_hash
;
3715 struct ftrace_hash
*hash
;
3718 if (unlikely(ftrace_disabled
))
3721 mutex_lock(&ops
->regex_lock
);
3724 orig_hash
= &ops
->filter_hash
;
3726 orig_hash
= &ops
->notrace_hash
;
3728 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3731 goto out_regex_unlock
;
3735 ftrace_filter_reset(hash
);
3736 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
3738 goto out_regex_unlock
;
3741 ret
= ftrace_match_addr(hash
, ip
, remove
);
3743 goto out_regex_unlock
;
3746 mutex_lock(&ftrace_lock
);
3747 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3749 ftrace_ops_update_code(ops
);
3751 mutex_unlock(&ftrace_lock
);
3754 mutex_unlock(&ops
->regex_lock
);
3756 free_ftrace_hash(hash
);
3761 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
3762 int reset
, int enable
)
3764 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
3768 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3769 * @ops - the ops to set the filter with
3770 * @ip - the address to add to or remove from the filter.
3771 * @remove - non zero to remove the ip from the filter
3772 * @reset - non zero to reset all filters before applying this filter.
3774 * Filters denote which functions should be enabled when tracing is enabled
3775 * If @ip is NULL, it failes to update filter.
3777 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
3778 int remove
, int reset
)
3780 ftrace_ops_init(ops
);
3781 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
3783 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
3786 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3787 int reset
, int enable
)
3789 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
3793 * ftrace_set_filter - set a function to filter on in ftrace
3794 * @ops - the ops to set the filter with
3795 * @buf - the string that holds the function filter text.
3796 * @len - the length of the string.
3797 * @reset - non zero to reset all filters before applying this filter.
3799 * Filters denote which functions should be enabled when tracing is enabled.
3800 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3802 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
3805 ftrace_ops_init(ops
);
3806 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
3808 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
3811 * ftrace_set_notrace - set a function to not trace in ftrace
3812 * @ops - the ops to set the notrace filter with
3813 * @buf - the string that holds the function notrace text.
3814 * @len - the length of the string.
3815 * @reset - non zero to reset all filters before applying this filter.
3817 * Notrace Filters denote which functions should not be enabled when tracing
3818 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3821 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
3824 ftrace_ops_init(ops
);
3825 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
3827 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
3829 * ftrace_set_global_filter - set a function to filter on with global tracers
3830 * @buf - the string that holds the function filter text.
3831 * @len - the length of the string.
3832 * @reset - non zero to reset all filters before applying this filter.
3834 * Filters denote which functions should be enabled when tracing is enabled.
3835 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3837 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
3839 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
3841 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
3844 * ftrace_set_global_notrace - set a function to not trace with global tracers
3845 * @buf - the string that holds the function notrace text.
3846 * @len - the length of the string.
3847 * @reset - non zero to reset all filters before applying this filter.
3849 * Notrace Filters denote which functions should not be enabled when tracing
3850 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3853 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
3855 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
3857 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
3860 * command line interface to allow users to set filters on boot up.
3862 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3863 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3864 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3866 /* Used by function selftest to not test if filter is set */
3867 bool ftrace_filter_param __initdata
;
3869 static int __init
set_ftrace_notrace(char *str
)
3871 ftrace_filter_param
= true;
3872 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
3875 __setup("ftrace_notrace=", set_ftrace_notrace
);
3877 static int __init
set_ftrace_filter(char *str
)
3879 ftrace_filter_param
= true;
3880 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
3883 __setup("ftrace_filter=", set_ftrace_filter
);
3885 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3886 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3887 static char ftrace_graph_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3888 static int ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
);
3890 static int __init
set_graph_function(char *str
)
3892 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
3895 __setup("ftrace_graph_filter=", set_graph_function
);
3897 static int __init
set_graph_notrace_function(char *str
)
3899 strlcpy(ftrace_graph_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
3902 __setup("ftrace_graph_notrace=", set_graph_notrace_function
);
3904 static void __init
set_ftrace_early_graph(char *buf
, int enable
)
3908 unsigned long *table
= ftrace_graph_funcs
;
3909 int *count
= &ftrace_graph_count
;
3912 table
= ftrace_graph_notrace_funcs
;
3913 count
= &ftrace_graph_notrace_count
;
3917 func
= strsep(&buf
, ",");
3918 /* we allow only one expression at a time */
3919 ret
= ftrace_set_func(table
, count
, FTRACE_GRAPH_MAX_FUNCS
, func
);
3921 printk(KERN_DEBUG
"ftrace: function %s not "
3922 "traceable\n", func
);
3925 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3928 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
3932 ftrace_ops_init(ops
);
3935 func
= strsep(&buf
, ",");
3936 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
3940 static void __init
set_ftrace_early_filters(void)
3942 if (ftrace_filter_buf
[0])
3943 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
3944 if (ftrace_notrace_buf
[0])
3945 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
3946 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3947 if (ftrace_graph_buf
[0])
3948 set_ftrace_early_graph(ftrace_graph_buf
, 1);
3949 if (ftrace_graph_notrace_buf
[0])
3950 set_ftrace_early_graph(ftrace_graph_notrace_buf
, 0);
3951 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3954 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
3956 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
3957 struct ftrace_iterator
*iter
;
3958 struct ftrace_hash
**orig_hash
;
3959 struct trace_parser
*parser
;
3963 if (file
->f_mode
& FMODE_READ
) {
3965 seq_release(inode
, file
);
3967 iter
= file
->private_data
;
3969 parser
= &iter
->parser
;
3970 if (trace_parser_loaded(parser
)) {
3971 parser
->buffer
[parser
->idx
] = 0;
3972 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
3975 trace_parser_put(parser
);
3977 mutex_lock(&iter
->ops
->regex_lock
);
3979 if (file
->f_mode
& FMODE_WRITE
) {
3980 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
3983 orig_hash
= &iter
->ops
->filter_hash
;
3985 orig_hash
= &iter
->ops
->notrace_hash
;
3987 mutex_lock(&ftrace_lock
);
3988 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
3989 orig_hash
, iter
->hash
);
3991 ftrace_ops_update_code(iter
->ops
);
3993 mutex_unlock(&ftrace_lock
);
3996 mutex_unlock(&iter
->ops
->regex_lock
);
3997 free_ftrace_hash(iter
->hash
);
4003 static const struct file_operations ftrace_avail_fops
= {
4004 .open
= ftrace_avail_open
,
4006 .llseek
= seq_lseek
,
4007 .release
= seq_release_private
,
4010 static const struct file_operations ftrace_enabled_fops
= {
4011 .open
= ftrace_enabled_open
,
4013 .llseek
= seq_lseek
,
4014 .release
= seq_release_private
,
4017 static const struct file_operations ftrace_filter_fops
= {
4018 .open
= ftrace_filter_open
,
4020 .write
= ftrace_filter_write
,
4021 .llseek
= tracing_lseek
,
4022 .release
= ftrace_regex_release
,
4025 static const struct file_operations ftrace_notrace_fops
= {
4026 .open
= ftrace_notrace_open
,
4028 .write
= ftrace_notrace_write
,
4029 .llseek
= tracing_lseek
,
4030 .release
= ftrace_regex_release
,
4033 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4035 static DEFINE_MUTEX(graph_lock
);
4037 int ftrace_graph_count
;
4038 int ftrace_graph_notrace_count
;
4039 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4040 unsigned long ftrace_graph_notrace_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4042 struct ftrace_graph_data
{
4043 unsigned long *table
;
4046 const struct seq_operations
*seq_ops
;
4050 __g_next(struct seq_file
*m
, loff_t
*pos
)
4052 struct ftrace_graph_data
*fgd
= m
->private;
4054 if (*pos
>= *fgd
->count
)
4056 return &fgd
->table
[*pos
];
4060 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4063 return __g_next(m
, pos
);
4066 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
4068 struct ftrace_graph_data
*fgd
= m
->private;
4070 mutex_lock(&graph_lock
);
4072 /* Nothing, tell g_show to print all functions are enabled */
4073 if (!*fgd
->count
&& !*pos
)
4076 return __g_next(m
, pos
);
4079 static void g_stop(struct seq_file
*m
, void *p
)
4081 mutex_unlock(&graph_lock
);
4084 static int g_show(struct seq_file
*m
, void *v
)
4086 unsigned long *ptr
= v
;
4091 if (ptr
== (unsigned long *)1) {
4092 seq_printf(m
, "#### all functions enabled ####\n");
4096 seq_printf(m
, "%ps\n", (void *)*ptr
);
4101 static const struct seq_operations ftrace_graph_seq_ops
= {
4109 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
4110 struct ftrace_graph_data
*fgd
)
4114 mutex_lock(&graph_lock
);
4115 if ((file
->f_mode
& FMODE_WRITE
) &&
4116 (file
->f_flags
& O_TRUNC
)) {
4118 memset(fgd
->table
, 0, fgd
->size
* sizeof(*fgd
->table
));
4120 mutex_unlock(&graph_lock
);
4122 if (file
->f_mode
& FMODE_READ
) {
4123 ret
= seq_open(file
, fgd
->seq_ops
);
4125 struct seq_file
*m
= file
->private_data
;
4129 file
->private_data
= fgd
;
4135 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
4137 struct ftrace_graph_data
*fgd
;
4139 if (unlikely(ftrace_disabled
))
4142 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4146 fgd
->table
= ftrace_graph_funcs
;
4147 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4148 fgd
->count
= &ftrace_graph_count
;
4149 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4151 return __ftrace_graph_open(inode
, file
, fgd
);
4155 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
4157 struct ftrace_graph_data
*fgd
;
4159 if (unlikely(ftrace_disabled
))
4162 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4166 fgd
->table
= ftrace_graph_notrace_funcs
;
4167 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4168 fgd
->count
= &ftrace_graph_notrace_count
;
4169 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4171 return __ftrace_graph_open(inode
, file
, fgd
);
4175 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
4177 if (file
->f_mode
& FMODE_READ
) {
4178 struct seq_file
*m
= file
->private_data
;
4181 seq_release(inode
, file
);
4183 kfree(file
->private_data
);
4190 ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
)
4192 struct dyn_ftrace
*rec
;
4193 struct ftrace_page
*pg
;
4202 type
= filter_parse_regex(buffer
, strlen(buffer
), &search
, ¬);
4203 if (!not && *idx
>= size
)
4206 search_len
= strlen(search
);
4208 mutex_lock(&ftrace_lock
);
4210 if (unlikely(ftrace_disabled
)) {
4211 mutex_unlock(&ftrace_lock
);
4215 do_for_each_ftrace_rec(pg
, rec
) {
4217 if (ftrace_match_record(rec
, NULL
, search
, search_len
, type
)) {
4218 /* if it is in the array */
4220 for (i
= 0; i
< *idx
; i
++) {
4221 if (array
[i
] == rec
->ip
) {
4230 array
[(*idx
)++] = rec
->ip
;
4236 array
[i
] = array
[--(*idx
)];
4242 } while_for_each_ftrace_rec();
4244 mutex_unlock(&ftrace_lock
);
4253 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
4254 size_t cnt
, loff_t
*ppos
)
4256 struct trace_parser parser
;
4257 ssize_t read
, ret
= 0;
4258 struct ftrace_graph_data
*fgd
= file
->private_data
;
4263 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
))
4266 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
4268 if (read
>= 0 && trace_parser_loaded((&parser
))) {
4269 parser
.buffer
[parser
.idx
] = 0;
4271 mutex_lock(&graph_lock
);
4273 /* we allow only one expression at a time */
4274 ret
= ftrace_set_func(fgd
->table
, fgd
->count
, fgd
->size
,
4277 mutex_unlock(&graph_lock
);
4283 trace_parser_put(&parser
);
4288 static const struct file_operations ftrace_graph_fops
= {
4289 .open
= ftrace_graph_open
,
4291 .write
= ftrace_graph_write
,
4292 .llseek
= tracing_lseek
,
4293 .release
= ftrace_graph_release
,
4296 static const struct file_operations ftrace_graph_notrace_fops
= {
4297 .open
= ftrace_graph_notrace_open
,
4299 .write
= ftrace_graph_write
,
4300 .llseek
= tracing_lseek
,
4301 .release
= ftrace_graph_release
,
4303 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4305 void ftrace_create_filter_files(struct ftrace_ops
*ops
,
4306 struct dentry
*parent
)
4309 trace_create_file("set_ftrace_filter", 0644, parent
,
4310 ops
, &ftrace_filter_fops
);
4312 trace_create_file("set_ftrace_notrace", 0644, parent
,
4313 ops
, &ftrace_notrace_fops
);
4317 * The name "destroy_filter_files" is really a misnomer. Although
4318 * in the future, it may actualy delete the files, but this is
4319 * really intended to make sure the ops passed in are disabled
4320 * and that when this function returns, the caller is free to
4323 * The "destroy" name is only to match the "create" name that this
4324 * should be paired with.
4326 void ftrace_destroy_filter_files(struct ftrace_ops
*ops
)
4328 mutex_lock(&ftrace_lock
);
4329 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
)
4330 ftrace_shutdown(ops
, 0);
4331 ops
->flags
|= FTRACE_OPS_FL_DELETED
;
4332 mutex_unlock(&ftrace_lock
);
4335 static __init
int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
)
4338 trace_create_file("available_filter_functions", 0444,
4339 d_tracer
, NULL
, &ftrace_avail_fops
);
4341 trace_create_file("enabled_functions", 0444,
4342 d_tracer
, NULL
, &ftrace_enabled_fops
);
4344 ftrace_create_filter_files(&global_ops
, d_tracer
);
4346 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4347 trace_create_file("set_graph_function", 0444, d_tracer
,
4349 &ftrace_graph_fops
);
4350 trace_create_file("set_graph_notrace", 0444, d_tracer
,
4352 &ftrace_graph_notrace_fops
);
4353 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4358 static int ftrace_cmp_ips(const void *a
, const void *b
)
4360 const unsigned long *ipa
= a
;
4361 const unsigned long *ipb
= b
;
4370 static void ftrace_swap_ips(void *a
, void *b
, int size
)
4372 unsigned long *ipa
= a
;
4373 unsigned long *ipb
= b
;
4381 static int ftrace_process_locs(struct module
*mod
,
4382 unsigned long *start
,
4385 struct ftrace_page
*start_pg
;
4386 struct ftrace_page
*pg
;
4387 struct dyn_ftrace
*rec
;
4388 unsigned long count
;
4391 unsigned long flags
= 0; /* Shut up gcc */
4394 count
= end
- start
;
4399 sort(start
, count
, sizeof(*start
),
4400 ftrace_cmp_ips
, ftrace_swap_ips
);
4402 start_pg
= ftrace_allocate_pages(count
);
4406 mutex_lock(&ftrace_lock
);
4409 * Core and each module needs their own pages, as
4410 * modules will free them when they are removed.
4411 * Force a new page to be allocated for modules.
4414 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
4415 /* First initialization */
4416 ftrace_pages
= ftrace_pages_start
= start_pg
;
4421 if (WARN_ON(ftrace_pages
->next
)) {
4422 /* Hmm, we have free pages? */
4423 while (ftrace_pages
->next
)
4424 ftrace_pages
= ftrace_pages
->next
;
4427 ftrace_pages
->next
= start_pg
;
4433 addr
= ftrace_call_adjust(*p
++);
4435 * Some architecture linkers will pad between
4436 * the different mcount_loc sections of different
4437 * object files to satisfy alignments.
4438 * Skip any NULL pointers.
4443 if (pg
->index
== pg
->size
) {
4444 /* We should have allocated enough */
4445 if (WARN_ON(!pg
->next
))
4450 rec
= &pg
->records
[pg
->index
++];
4454 /* We should have used all pages */
4457 /* Assign the last page to ftrace_pages */
4461 * We only need to disable interrupts on start up
4462 * because we are modifying code that an interrupt
4463 * may execute, and the modification is not atomic.
4464 * But for modules, nothing runs the code we modify
4465 * until we are finished with it, and there's no
4466 * reason to cause large interrupt latencies while we do it.
4469 local_irq_save(flags
);
4470 ftrace_update_code(mod
, start_pg
);
4472 local_irq_restore(flags
);
4475 mutex_unlock(&ftrace_lock
);
4480 #ifdef CONFIG_MODULES
4482 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4484 void ftrace_release_mod(struct module
*mod
)
4486 struct dyn_ftrace
*rec
;
4487 struct ftrace_page
**last_pg
;
4488 struct ftrace_page
*pg
;
4491 mutex_lock(&ftrace_lock
);
4493 if (ftrace_disabled
)
4497 * Each module has its own ftrace_pages, remove
4498 * them from the list.
4500 last_pg
= &ftrace_pages_start
;
4501 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
4502 rec
= &pg
->records
[0];
4503 if (within_module_core(rec
->ip
, mod
)) {
4505 * As core pages are first, the first
4506 * page should never be a module page.
4508 if (WARN_ON(pg
== ftrace_pages_start
))
4511 /* Check if we are deleting the last page */
4512 if (pg
== ftrace_pages
)
4513 ftrace_pages
= next_to_ftrace_page(last_pg
);
4515 *last_pg
= pg
->next
;
4516 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
4517 free_pages((unsigned long)pg
->records
, order
);
4520 last_pg
= &pg
->next
;
4523 mutex_unlock(&ftrace_lock
);
4526 static void ftrace_init_module(struct module
*mod
,
4527 unsigned long *start
, unsigned long *end
)
4529 if (ftrace_disabled
|| start
== end
)
4531 ftrace_process_locs(mod
, start
, end
);
4534 void ftrace_module_init(struct module
*mod
)
4536 ftrace_init_module(mod
, mod
->ftrace_callsites
,
4537 mod
->ftrace_callsites
+
4538 mod
->num_ftrace_callsites
);
4541 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4542 unsigned long val
, void *data
)
4544 struct module
*mod
= data
;
4546 if (val
== MODULE_STATE_GOING
)
4547 ftrace_release_mod(mod
);
4552 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4553 unsigned long val
, void *data
)
4557 #endif /* CONFIG_MODULES */
4559 struct notifier_block ftrace_module_exit_nb
= {
4560 .notifier_call
= ftrace_module_notify_exit
,
4561 .priority
= INT_MIN
, /* Run after anything that can remove kprobes */
4564 void __init
ftrace_init(void)
4566 extern unsigned long __start_mcount_loc
[];
4567 extern unsigned long __stop_mcount_loc
[];
4568 unsigned long count
, flags
;
4571 local_irq_save(flags
);
4572 ret
= ftrace_dyn_arch_init();
4573 local_irq_restore(flags
);
4577 count
= __stop_mcount_loc
- __start_mcount_loc
;
4579 pr_info("ftrace: No functions to be traced?\n");
4583 pr_info("ftrace: allocating %ld entries in %ld pages\n",
4584 count
, count
/ ENTRIES_PER_PAGE
+ 1);
4586 last_ftrace_enabled
= ftrace_enabled
= 1;
4588 ret
= ftrace_process_locs(NULL
,
4592 ret
= register_module_notifier(&ftrace_module_exit_nb
);
4594 pr_warning("Failed to register trace ftrace module exit notifier\n");
4596 set_ftrace_early_filters();
4600 ftrace_disabled
= 1;
4605 static struct ftrace_ops global_ops
= {
4606 .func
= ftrace_stub
,
4607 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4608 INIT_REGEX_LOCK(global_ops
)
4611 static int __init
ftrace_nodyn_init(void)
4616 core_initcall(ftrace_nodyn_init
);
4618 static inline int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
) { return 0; }
4619 static inline void ftrace_startup_enable(int command
) { }
4620 /* Keep as macros so we do not need to define the commands */
4621 # define ftrace_startup(ops, command) \
4623 int ___ret = __register_ftrace_function(ops); \
4625 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4628 # define ftrace_shutdown(ops, command) \
4630 int ___ret = __unregister_ftrace_function(ops); \
4632 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
4636 # define ftrace_startup_sysctl() do { } while (0)
4637 # define ftrace_shutdown_sysctl() do { } while (0)
4640 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
4645 #endif /* CONFIG_DYNAMIC_FTRACE */
4647 __init
void ftrace_init_global_array_ops(struct trace_array
*tr
)
4649 tr
->ops
= &global_ops
;
4650 tr
->ops
->private = tr
;
4653 void ftrace_init_array_ops(struct trace_array
*tr
, ftrace_func_t func
)
4655 /* If we filter on pids, update to use the pid function */
4656 if (tr
->flags
& TRACE_ARRAY_FL_GLOBAL
) {
4657 if (WARN_ON(tr
->ops
->func
!= ftrace_stub
))
4658 printk("ftrace ops had %pS for function\n",
4660 /* Only the top level instance does pid tracing */
4661 if (!list_empty(&ftrace_pids
)) {
4662 set_ftrace_pid_function(func
);
4663 func
= ftrace_pid_func
;
4666 tr
->ops
->func
= func
;
4667 tr
->ops
->private = tr
;
4670 void ftrace_reset_array_ops(struct trace_array
*tr
)
4672 tr
->ops
->func
= ftrace_stub
;
4676 ftrace_ops_control_func(unsigned long ip
, unsigned long parent_ip
,
4677 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4679 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT
)))
4683 * Some of the ops may be dynamically allocated,
4684 * they must be freed after a synchronize_sched().
4686 preempt_disable_notrace();
4687 trace_recursion_set(TRACE_CONTROL_BIT
);
4690 * Control funcs (perf) uses RCU. Only trace if
4691 * RCU is currently active.
4693 if (!rcu_is_watching())
4696 do_for_each_ftrace_op(op
, ftrace_control_list
) {
4697 if (!(op
->flags
& FTRACE_OPS_FL_STUB
) &&
4698 !ftrace_function_local_disabled(op
) &&
4699 ftrace_ops_test(op
, ip
, regs
))
4700 op
->func(ip
, parent_ip
, op
, regs
);
4701 } while_for_each_ftrace_op(op
);
4703 trace_recursion_clear(TRACE_CONTROL_BIT
);
4704 preempt_enable_notrace();
4707 static struct ftrace_ops control_ops
= {
4708 .func
= ftrace_ops_control_func
,
4709 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4710 INIT_REGEX_LOCK(control_ops
)
4714 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4715 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
4717 struct ftrace_ops
*op
;
4720 if (function_trace_stop
)
4723 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
4728 * Some of the ops may be dynamically allocated,
4729 * they must be freed after a synchronize_sched().
4731 preempt_disable_notrace();
4732 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4733 if (ftrace_ops_test(op
, ip
, regs
)) {
4734 if (WARN_ON(!op
->func
)) {
4735 function_trace_stop
= 1;
4736 printk("op=%p %pS\n", op
, op
);
4739 op
->func(ip
, parent_ip
, op
, regs
);
4741 } while_for_each_ftrace_op(op
);
4743 preempt_enable_notrace();
4744 trace_clear_recursion(bit
);
4748 * Some archs only support passing ip and parent_ip. Even though
4749 * the list function ignores the op parameter, we do not want any
4750 * C side effects, where a function is called without the caller
4751 * sending a third parameter.
4752 * Archs are to support both the regs and ftrace_ops at the same time.
4753 * If they support ftrace_ops, it is assumed they support regs.
4754 * If call backs want to use regs, they must either check for regs
4755 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4756 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4757 * An architecture can pass partial regs with ftrace_ops and still
4758 * set the ARCH_SUPPORT_FTARCE_OPS.
4760 #if ARCH_SUPPORTS_FTRACE_OPS
4761 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4762 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4764 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
4767 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
4769 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
4773 static void clear_ftrace_swapper(void)
4775 struct task_struct
*p
;
4779 for_each_online_cpu(cpu
) {
4781 clear_tsk_trace_trace(p
);
4786 static void set_ftrace_swapper(void)
4788 struct task_struct
*p
;
4792 for_each_online_cpu(cpu
) {
4794 set_tsk_trace_trace(p
);
4799 static void clear_ftrace_pid(struct pid
*pid
)
4801 struct task_struct
*p
;
4804 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4805 clear_tsk_trace_trace(p
);
4806 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4812 static void set_ftrace_pid(struct pid
*pid
)
4814 struct task_struct
*p
;
4817 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4818 set_tsk_trace_trace(p
);
4819 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4823 static void clear_ftrace_pid_task(struct pid
*pid
)
4825 if (pid
== ftrace_swapper_pid
)
4826 clear_ftrace_swapper();
4828 clear_ftrace_pid(pid
);
4831 static void set_ftrace_pid_task(struct pid
*pid
)
4833 if (pid
== ftrace_swapper_pid
)
4834 set_ftrace_swapper();
4836 set_ftrace_pid(pid
);
4839 static int ftrace_pid_add(int p
)
4842 struct ftrace_pid
*fpid
;
4845 mutex_lock(&ftrace_lock
);
4848 pid
= ftrace_swapper_pid
;
4850 pid
= find_get_pid(p
);
4857 list_for_each_entry(fpid
, &ftrace_pids
, list
)
4858 if (fpid
->pid
== pid
)
4863 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
4867 list_add(&fpid
->list
, &ftrace_pids
);
4870 set_ftrace_pid_task(pid
);
4872 ftrace_update_pid_func();
4873 ftrace_startup_enable(0);
4875 mutex_unlock(&ftrace_lock
);
4879 if (pid
!= ftrace_swapper_pid
)
4883 mutex_unlock(&ftrace_lock
);
4887 static void ftrace_pid_reset(void)
4889 struct ftrace_pid
*fpid
, *safe
;
4891 mutex_lock(&ftrace_lock
);
4892 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
4893 struct pid
*pid
= fpid
->pid
;
4895 clear_ftrace_pid_task(pid
);
4897 list_del(&fpid
->list
);
4901 ftrace_update_pid_func();
4902 ftrace_startup_enable(0);
4904 mutex_unlock(&ftrace_lock
);
4907 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
4909 mutex_lock(&ftrace_lock
);
4911 if (list_empty(&ftrace_pids
) && (!*pos
))
4914 return seq_list_start(&ftrace_pids
, *pos
);
4917 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4922 return seq_list_next(v
, &ftrace_pids
, pos
);
4925 static void fpid_stop(struct seq_file
*m
, void *p
)
4927 mutex_unlock(&ftrace_lock
);
4930 static int fpid_show(struct seq_file
*m
, void *v
)
4932 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
4934 if (v
== (void *)1) {
4935 seq_printf(m
, "no pid\n");
4939 if (fpid
->pid
== ftrace_swapper_pid
)
4940 seq_printf(m
, "swapper tasks\n");
4942 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
4947 static const struct seq_operations ftrace_pid_sops
= {
4948 .start
= fpid_start
,
4955 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
4959 if ((file
->f_mode
& FMODE_WRITE
) &&
4960 (file
->f_flags
& O_TRUNC
))
4963 if (file
->f_mode
& FMODE_READ
)
4964 ret
= seq_open(file
, &ftrace_pid_sops
);
4970 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
4971 size_t cnt
, loff_t
*ppos
)
4977 if (cnt
>= sizeof(buf
))
4980 if (copy_from_user(&buf
, ubuf
, cnt
))
4986 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4987 * to clean the filter quietly.
4989 tmp
= strstrip(buf
);
4990 if (strlen(tmp
) == 0)
4993 ret
= kstrtol(tmp
, 10, &val
);
4997 ret
= ftrace_pid_add(val
);
4999 return ret
? ret
: cnt
;
5003 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
5005 if (file
->f_mode
& FMODE_READ
)
5006 seq_release(inode
, file
);
5011 static const struct file_operations ftrace_pid_fops
= {
5012 .open
= ftrace_pid_open
,
5013 .write
= ftrace_pid_write
,
5015 .llseek
= tracing_lseek
,
5016 .release
= ftrace_pid_release
,
5019 static __init
int ftrace_init_debugfs(void)
5021 struct dentry
*d_tracer
;
5023 d_tracer
= tracing_init_dentry();
5027 ftrace_init_dyn_debugfs(d_tracer
);
5029 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
5030 NULL
, &ftrace_pid_fops
);
5032 ftrace_profile_debugfs(d_tracer
);
5036 fs_initcall(ftrace_init_debugfs
);
5039 * ftrace_kill - kill ftrace
5041 * This function should be used by panic code. It stops ftrace
5042 * but in a not so nice way. If you need to simply kill ftrace
5043 * from a non-atomic section, use ftrace_kill.
5045 void ftrace_kill(void)
5047 ftrace_disabled
= 1;
5049 clear_ftrace_function();
5053 * Test if ftrace is dead or not.
5055 int ftrace_is_dead(void)
5057 return ftrace_disabled
;
5061 * register_ftrace_function - register a function for profiling
5062 * @ops - ops structure that holds the function for profiling.
5064 * Register a function to be called by all functions in the
5067 * Note: @ops->func and all the functions it calls must be labeled
5068 * with "notrace", otherwise it will go into a
5071 int register_ftrace_function(struct ftrace_ops
*ops
)
5075 ftrace_ops_init(ops
);
5077 mutex_lock(&ftrace_lock
);
5079 ret
= ftrace_startup(ops
, 0);
5081 mutex_unlock(&ftrace_lock
);
5085 EXPORT_SYMBOL_GPL(register_ftrace_function
);
5088 * unregister_ftrace_function - unregister a function for profiling.
5089 * @ops - ops structure that holds the function to unregister
5091 * Unregister a function that was added to be called by ftrace profiling.
5093 int unregister_ftrace_function(struct ftrace_ops
*ops
)
5097 mutex_lock(&ftrace_lock
);
5098 ret
= ftrace_shutdown(ops
, 0);
5099 mutex_unlock(&ftrace_lock
);
5103 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
5106 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
5107 void __user
*buffer
, size_t *lenp
,
5112 mutex_lock(&ftrace_lock
);
5114 if (unlikely(ftrace_disabled
))
5117 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
5119 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
5122 last_ftrace_enabled
= !!ftrace_enabled
;
5124 if (ftrace_enabled
) {
5126 ftrace_startup_sysctl();
5128 /* we are starting ftrace again */
5129 if (ftrace_ops_list
!= &ftrace_list_end
)
5130 update_ftrace_function();
5133 /* stopping ftrace calls (just send to ftrace_stub) */
5134 ftrace_trace_function
= ftrace_stub
;
5136 ftrace_shutdown_sysctl();
5140 mutex_unlock(&ftrace_lock
);
5144 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5146 static int ftrace_graph_active
;
5148 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
5153 /* The callbacks that hook a function */
5154 trace_func_graph_ret_t ftrace_graph_return
=
5155 (trace_func_graph_ret_t
)ftrace_stub
;
5156 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
5157 static trace_func_graph_ent_t __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5159 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5160 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
5164 unsigned long flags
;
5165 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
5166 struct task_struct
*g
, *t
;
5168 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
5169 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
5170 * sizeof(struct ftrace_ret_stack
),
5172 if (!ret_stack_list
[i
]) {
5180 read_lock_irqsave(&tasklist_lock
, flags
);
5181 do_each_thread(g
, t
) {
5187 if (t
->ret_stack
== NULL
) {
5188 atomic_set(&t
->tracing_graph_pause
, 0);
5189 atomic_set(&t
->trace_overrun
, 0);
5190 t
->curr_ret_stack
= -1;
5191 /* Make sure the tasks see the -1 first: */
5193 t
->ret_stack
= ret_stack_list
[start
++];
5195 } while_each_thread(g
, t
);
5198 read_unlock_irqrestore(&tasklist_lock
, flags
);
5200 for (i
= start
; i
< end
; i
++)
5201 kfree(ret_stack_list
[i
]);
5206 ftrace_graph_probe_sched_switch(void *ignore
,
5207 struct task_struct
*prev
, struct task_struct
*next
)
5209 unsigned long long timestamp
;
5213 * Does the user want to count the time a function was asleep.
5214 * If so, do not update the time stamps.
5216 if (trace_flags
& TRACE_ITER_SLEEP_TIME
)
5219 timestamp
= trace_clock_local();
5221 prev
->ftrace_timestamp
= timestamp
;
5223 /* only process tasks that we timestamped */
5224 if (!next
->ftrace_timestamp
)
5228 * Update all the counters in next to make up for the
5229 * time next was sleeping.
5231 timestamp
-= next
->ftrace_timestamp
;
5233 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
5234 next
->ret_stack
[index
].calltime
+= timestamp
;
5237 /* Allocate a return stack for each task */
5238 static int start_graph_tracing(void)
5240 struct ftrace_ret_stack
**ret_stack_list
;
5243 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
5244 sizeof(struct ftrace_ret_stack
*),
5247 if (!ret_stack_list
)
5250 /* The cpu_boot init_task->ret_stack will never be freed */
5251 for_each_online_cpu(cpu
) {
5252 if (!idle_task(cpu
)->ret_stack
)
5253 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
5257 ret
= alloc_retstack_tasklist(ret_stack_list
);
5258 } while (ret
== -EAGAIN
);
5261 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5263 pr_info("ftrace_graph: Couldn't activate tracepoint"
5264 " probe to kernel_sched_switch\n");
5267 kfree(ret_stack_list
);
5272 * Hibernation protection.
5273 * The state of the current task is too much unstable during
5274 * suspend/restore to disk. We want to protect against that.
5277 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
5281 case PM_HIBERNATION_PREPARE
:
5282 pause_graph_tracing();
5285 case PM_POST_HIBERNATION
:
5286 unpause_graph_tracing();
5292 static int ftrace_graph_entry_test(struct ftrace_graph_ent
*trace
)
5294 if (!ftrace_ops_test(&global_ops
, trace
->func
, NULL
))
5296 return __ftrace_graph_entry(trace
);
5300 * The function graph tracer should only trace the functions defined
5301 * by set_ftrace_filter and set_ftrace_notrace. If another function
5302 * tracer ops is registered, the graph tracer requires testing the
5303 * function against the global ops, and not just trace any function
5304 * that any ftrace_ops registered.
5306 static void update_function_graph_func(void)
5308 if (ftrace_ops_list
== &ftrace_list_end
||
5309 (ftrace_ops_list
== &global_ops
&&
5310 global_ops
.next
== &ftrace_list_end
))
5311 ftrace_graph_entry
= __ftrace_graph_entry
;
5313 ftrace_graph_entry
= ftrace_graph_entry_test
;
5316 static struct notifier_block ftrace_suspend_notifier
= {
5317 .notifier_call
= ftrace_suspend_notifier_call
,
5320 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
5321 trace_func_graph_ent_t entryfunc
)
5325 mutex_lock(&ftrace_lock
);
5327 /* we currently allow only one tracer registered at a time */
5328 if (ftrace_graph_active
) {
5333 register_pm_notifier(&ftrace_suspend_notifier
);
5335 ftrace_graph_active
++;
5336 ret
= start_graph_tracing();
5338 ftrace_graph_active
--;
5342 ftrace_graph_return
= retfunc
;
5345 * Update the indirect function to the entryfunc, and the
5346 * function that gets called to the entry_test first. Then
5347 * call the update fgraph entry function to determine if
5348 * the entryfunc should be called directly or not.
5350 __ftrace_graph_entry
= entryfunc
;
5351 ftrace_graph_entry
= ftrace_graph_entry_test
;
5352 update_function_graph_func();
5354 /* Function graph doesn't use the .func field of global_ops */
5355 global_ops
.flags
|= FTRACE_OPS_FL_STUB
;
5357 #ifdef CONFIG_DYNAMIC_FTRACE
5358 /* Optimize function graph calling (if implemented by arch) */
5359 global_ops
.trampoline
= FTRACE_GRAPH_ADDR
;
5362 ret
= ftrace_startup(&global_ops
, FTRACE_START_FUNC_RET
);
5365 mutex_unlock(&ftrace_lock
);
5369 void unregister_ftrace_graph(void)
5371 mutex_lock(&ftrace_lock
);
5373 if (unlikely(!ftrace_graph_active
))
5376 ftrace_graph_active
--;
5377 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
5378 ftrace_graph_entry
= ftrace_graph_entry_stub
;
5379 __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5380 ftrace_shutdown(&global_ops
, FTRACE_STOP_FUNC_RET
);
5381 global_ops
.flags
&= ~FTRACE_OPS_FL_STUB
;
5382 #ifdef CONFIG_DYNAMIC_FTRACE
5383 global_ops
.trampoline
= 0;
5385 unregister_pm_notifier(&ftrace_suspend_notifier
);
5386 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5389 mutex_unlock(&ftrace_lock
);
5392 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
5395 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
5397 atomic_set(&t
->tracing_graph_pause
, 0);
5398 atomic_set(&t
->trace_overrun
, 0);
5399 t
->ftrace_timestamp
= 0;
5400 /* make curr_ret_stack visible before we add the ret_stack */
5402 t
->ret_stack
= ret_stack
;
5406 * Allocate a return stack for the idle task. May be the first
5407 * time through, or it may be done by CPU hotplug online.
5409 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
5411 t
->curr_ret_stack
= -1;
5413 * The idle task has no parent, it either has its own
5414 * stack or no stack at all.
5417 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
5419 if (ftrace_graph_active
) {
5420 struct ftrace_ret_stack
*ret_stack
;
5422 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
5424 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5425 * sizeof(struct ftrace_ret_stack
),
5429 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
5431 graph_init_task(t
, ret_stack
);
5435 /* Allocate a return stack for newly created task */
5436 void ftrace_graph_init_task(struct task_struct
*t
)
5438 /* Make sure we do not use the parent ret_stack */
5439 t
->ret_stack
= NULL
;
5440 t
->curr_ret_stack
= -1;
5442 if (ftrace_graph_active
) {
5443 struct ftrace_ret_stack
*ret_stack
;
5445 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5446 * sizeof(struct ftrace_ret_stack
),
5450 graph_init_task(t
, ret_stack
);
5454 void ftrace_graph_exit_task(struct task_struct
*t
)
5456 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
5458 t
->ret_stack
= NULL
;
5459 /* NULL must become visible to IRQs before we free it: */
5465 void ftrace_graph_stop(void)