2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 Nadia Yvette Chambers
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/kallsyms.h>
19 #include <linux/seq_file.h>
20 #include <linux/suspend.h>
21 #include <linux/debugfs.h>
22 #include <linux/hardirq.h>
23 #include <linux/kthread.h>
24 #include <linux/uaccess.h>
25 #include <linux/bsearch.h>
26 #include <linux/module.h>
27 #include <linux/ftrace.h>
28 #include <linux/sysctl.h>
29 #include <linux/slab.h>
30 #include <linux/ctype.h>
31 #include <linux/sort.h>
32 #include <linux/list.h>
33 #include <linux/hash.h>
34 #include <linux/rcupdate.h>
36 #include <trace/events/sched.h>
38 #include <asm/setup.h>
40 #include "trace_output.h"
41 #include "trace_stat.h"
43 #define FTRACE_WARN_ON(cond) \
51 #define FTRACE_WARN_ON_ONCE(cond) \
54 if (WARN_ON_ONCE(___r)) \
59 /* hash bits for specific function selection */
60 #define FTRACE_HASH_BITS 7
61 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
62 #define FTRACE_HASH_DEFAULT_BITS 10
63 #define FTRACE_HASH_MAX_BITS 12
65 #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
67 static struct ftrace_ops ftrace_list_end __read_mostly
= {
69 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_STUB
,
72 /* ftrace_enabled is a method to turn ftrace on or off */
73 int ftrace_enabled __read_mostly
;
74 static int last_ftrace_enabled
;
76 /* Quick disabling of function tracer. */
77 int function_trace_stop __read_mostly
;
79 /* Current function tracing op */
80 struct ftrace_ops
*function_trace_op __read_mostly
= &ftrace_list_end
;
82 /* List for set_ftrace_pid's pids. */
83 LIST_HEAD(ftrace_pids
);
85 struct list_head list
;
90 * ftrace_disabled is set when an anomaly is discovered.
91 * ftrace_disabled is much stronger than ftrace_enabled.
93 static int ftrace_disabled __read_mostly
;
95 static DEFINE_MUTEX(ftrace_lock
);
97 static struct ftrace_ops
*ftrace_global_list __read_mostly
= &ftrace_list_end
;
98 static struct ftrace_ops
*ftrace_control_list __read_mostly
= &ftrace_list_end
;
99 static struct ftrace_ops
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
100 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
101 ftrace_func_t ftrace_pid_function __read_mostly
= ftrace_stub
;
102 static struct ftrace_ops global_ops
;
103 static struct ftrace_ops control_ops
;
105 #if ARCH_SUPPORTS_FTRACE_OPS
106 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
107 struct ftrace_ops
*op
, struct pt_regs
*regs
);
109 /* See comment below, where ftrace_ops_list_func is defined */
110 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
111 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
115 * Traverse the ftrace_global_list, invoking all entries. The reason that we
116 * can use rcu_dereference_raw() is that elements removed from this list
117 * are simply leaked, so there is no need to interact with a grace-period
118 * mechanism. The rcu_dereference_raw() calls are needed to handle
119 * concurrent insertions into the ftrace_global_list.
121 * Silly Alpha and silly pointer-speculation compiler optimizations!
123 #define do_for_each_ftrace_op(op, list) \
124 op = rcu_dereference_raw(list); \
128 * Optimized for just a single item in the list (as that is the normal case).
130 #define while_for_each_ftrace_op(op) \
131 while (likely(op = rcu_dereference_raw((op)->next)) && \
132 unlikely((op) != &ftrace_list_end))
135 * ftrace_nr_registered_ops - return number of ops registered
137 * Returns the number of ftrace_ops registered and tracing functions
139 int ftrace_nr_registered_ops(void)
141 struct ftrace_ops
*ops
;
144 mutex_lock(&ftrace_lock
);
146 for (ops
= ftrace_ops_list
;
147 ops
!= &ftrace_list_end
; ops
= ops
->next
)
150 mutex_unlock(&ftrace_lock
);
156 ftrace_global_list_func(unsigned long ip
, unsigned long parent_ip
,
157 struct ftrace_ops
*op
, struct pt_regs
*regs
)
161 bit
= trace_test_and_set_recursion(TRACE_GLOBAL_START
, TRACE_GLOBAL_MAX
);
165 do_for_each_ftrace_op(op
, ftrace_global_list
) {
166 op
->func(ip
, parent_ip
, op
, regs
);
167 } while_for_each_ftrace_op(op
);
169 trace_clear_recursion(bit
);
172 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
173 struct ftrace_ops
*op
, struct pt_regs
*regs
)
175 if (!test_tsk_trace_trace(current
))
178 ftrace_pid_function(ip
, parent_ip
, op
, regs
);
181 static void set_ftrace_pid_function(ftrace_func_t func
)
183 /* do not set ftrace_pid_function to itself! */
184 if (func
!= ftrace_pid_func
)
185 ftrace_pid_function
= func
;
189 * clear_ftrace_function - reset the ftrace function
191 * This NULLs the ftrace function and in essence stops
192 * tracing. There may be lag
194 void clear_ftrace_function(void)
196 ftrace_trace_function
= ftrace_stub
;
197 ftrace_pid_function
= ftrace_stub
;
200 static void control_ops_disable_all(struct ftrace_ops
*ops
)
204 for_each_possible_cpu(cpu
)
205 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
208 static int control_ops_alloc(struct ftrace_ops
*ops
)
210 int __percpu
*disabled
;
212 disabled
= alloc_percpu(int);
216 ops
->disabled
= disabled
;
217 control_ops_disable_all(ops
);
221 static void control_ops_free(struct ftrace_ops
*ops
)
223 free_percpu(ops
->disabled
);
226 static void update_global_ops(void)
231 * If there's only one function registered, then call that
232 * function directly. Otherwise, we need to iterate over the
233 * registered callers.
235 if (ftrace_global_list
== &ftrace_list_end
||
236 ftrace_global_list
->next
== &ftrace_list_end
) {
237 func
= ftrace_global_list
->func
;
239 * As we are calling the function directly.
240 * If it does not have recursion protection,
241 * the function_trace_op needs to be updated
244 if (ftrace_global_list
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
)
245 global_ops
.flags
|= FTRACE_OPS_FL_RECURSION_SAFE
;
247 global_ops
.flags
&= ~FTRACE_OPS_FL_RECURSION_SAFE
;
249 func
= ftrace_global_list_func
;
250 /* The list has its own recursion protection. */
251 global_ops
.flags
|= FTRACE_OPS_FL_RECURSION_SAFE
;
255 /* If we filter on pids, update to use the pid function */
256 if (!list_empty(&ftrace_pids
)) {
257 set_ftrace_pid_function(func
);
258 func
= ftrace_pid_func
;
261 global_ops
.func
= func
;
264 static void update_ftrace_function(void)
271 * If we are at the end of the list and this ops is
272 * recursion safe and not dynamic and the arch supports passing ops,
273 * then have the mcount trampoline call the function directly.
275 if (ftrace_ops_list
== &ftrace_list_end
||
276 (ftrace_ops_list
->next
== &ftrace_list_end
&&
277 !(ftrace_ops_list
->flags
& FTRACE_OPS_FL_DYNAMIC
) &&
278 (ftrace_ops_list
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) &&
279 !FTRACE_FORCE_LIST_FUNC
)) {
280 /* Set the ftrace_ops that the arch callback uses */
281 if (ftrace_ops_list
== &global_ops
)
282 function_trace_op
= ftrace_global_list
;
284 function_trace_op
= ftrace_ops_list
;
285 func
= ftrace_ops_list
->func
;
287 /* Just use the default ftrace_ops */
288 function_trace_op
= &ftrace_list_end
;
289 func
= ftrace_ops_list_func
;
292 ftrace_trace_function
= func
;
295 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
299 * We are entering ops into the list but another
300 * CPU might be walking that list. We need to make sure
301 * the ops->next pointer is valid before another CPU sees
302 * the ops pointer included into the list.
304 rcu_assign_pointer(*list
, ops
);
307 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
309 struct ftrace_ops
**p
;
312 * If we are removing the last function, then simply point
313 * to the ftrace_stub.
315 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
316 *list
= &ftrace_list_end
;
320 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
331 static void add_ftrace_list_ops(struct ftrace_ops
**list
,
332 struct ftrace_ops
*main_ops
,
333 struct ftrace_ops
*ops
)
335 int first
= *list
== &ftrace_list_end
;
336 add_ftrace_ops(list
, ops
);
338 add_ftrace_ops(&ftrace_ops_list
, main_ops
);
341 static int remove_ftrace_list_ops(struct ftrace_ops
**list
,
342 struct ftrace_ops
*main_ops
,
343 struct ftrace_ops
*ops
)
345 int ret
= remove_ftrace_ops(list
, ops
);
346 if (!ret
&& *list
== &ftrace_list_end
)
347 ret
= remove_ftrace_ops(&ftrace_ops_list
, main_ops
);
351 static int __register_ftrace_function(struct ftrace_ops
*ops
)
353 if (unlikely(ftrace_disabled
))
356 if (FTRACE_WARN_ON(ops
== &global_ops
))
359 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
362 /* We don't support both control and global flags set. */
363 if ((ops
->flags
& FL_GLOBAL_CONTROL_MASK
) == FL_GLOBAL_CONTROL_MASK
)
366 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
368 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
369 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
370 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
372 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
373 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
376 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
377 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
380 if (!core_kernel_data((unsigned long)ops
))
381 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
383 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
384 add_ftrace_list_ops(&ftrace_global_list
, &global_ops
, ops
);
385 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
386 } else if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
387 if (control_ops_alloc(ops
))
389 add_ftrace_list_ops(&ftrace_control_list
, &control_ops
, ops
);
391 add_ftrace_ops(&ftrace_ops_list
, ops
);
394 update_ftrace_function();
399 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
406 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
409 if (FTRACE_WARN_ON(ops
== &global_ops
))
412 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
413 ret
= remove_ftrace_list_ops(&ftrace_global_list
,
416 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
417 } else if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
418 ret
= remove_ftrace_list_ops(&ftrace_control_list
,
422 * The ftrace_ops is now removed from the list,
423 * so there'll be no new users. We must ensure
424 * all current users are done before we free
428 control_ops_free(ops
);
431 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
437 update_ftrace_function();
440 * Dynamic ops may be freed, we must make sure that all
441 * callers are done before leaving this function.
443 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
)
449 static void ftrace_update_pid_func(void)
451 /* Only do something if we are tracing something */
452 if (ftrace_trace_function
== ftrace_stub
)
455 update_ftrace_function();
458 #ifdef CONFIG_FUNCTION_PROFILER
459 struct ftrace_profile
{
460 struct hlist_node node
;
462 unsigned long counter
;
463 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
464 unsigned long long time
;
465 unsigned long long time_squared
;
469 struct ftrace_profile_page
{
470 struct ftrace_profile_page
*next
;
472 struct ftrace_profile records
[];
475 struct ftrace_profile_stat
{
477 struct hlist_head
*hash
;
478 struct ftrace_profile_page
*pages
;
479 struct ftrace_profile_page
*start
;
480 struct tracer_stat stat
;
483 #define PROFILE_RECORDS_SIZE \
484 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
486 #define PROFILES_PER_PAGE \
487 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
489 static int ftrace_profile_bits __read_mostly
;
490 static int ftrace_profile_enabled __read_mostly
;
492 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
493 static DEFINE_MUTEX(ftrace_profile_lock
);
495 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
497 #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
500 function_stat_next(void *v
, int idx
)
502 struct ftrace_profile
*rec
= v
;
503 struct ftrace_profile_page
*pg
;
505 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
511 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
515 rec
= &pg
->records
[0];
523 static void *function_stat_start(struct tracer_stat
*trace
)
525 struct ftrace_profile_stat
*stat
=
526 container_of(trace
, struct ftrace_profile_stat
, stat
);
528 if (!stat
|| !stat
->start
)
531 return function_stat_next(&stat
->start
->records
[0], 0);
534 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
535 /* function graph compares on total time */
536 static int function_stat_cmp(void *p1
, void *p2
)
538 struct ftrace_profile
*a
= p1
;
539 struct ftrace_profile
*b
= p2
;
541 if (a
->time
< b
->time
)
543 if (a
->time
> b
->time
)
549 /* not function graph compares against hits */
550 static int function_stat_cmp(void *p1
, void *p2
)
552 struct ftrace_profile
*a
= p1
;
553 struct ftrace_profile
*b
= p2
;
555 if (a
->counter
< b
->counter
)
557 if (a
->counter
> b
->counter
)
564 static int function_stat_headers(struct seq_file
*m
)
566 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
567 seq_printf(m
, " Function "
570 "--- ---- --- ---\n");
572 seq_printf(m
, " Function Hit\n"
578 static int function_stat_show(struct seq_file
*m
, void *v
)
580 struct ftrace_profile
*rec
= v
;
581 char str
[KSYM_SYMBOL_LEN
];
583 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
584 static struct trace_seq s
;
585 unsigned long long avg
;
586 unsigned long long stddev
;
588 mutex_lock(&ftrace_profile_lock
);
590 /* we raced with function_profile_reset() */
591 if (unlikely(rec
->counter
== 0)) {
596 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
597 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
599 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
602 do_div(avg
, rec
->counter
);
604 /* Sample standard deviation (s^2) */
605 if (rec
->counter
<= 1)
608 stddev
= rec
->time_squared
- rec
->counter
* avg
* avg
;
610 * Divide only 1000 for ns^2 -> us^2 conversion.
611 * trace_print_graph_duration will divide 1000 again.
613 do_div(stddev
, (rec
->counter
- 1) * 1000);
617 trace_print_graph_duration(rec
->time
, &s
);
618 trace_seq_puts(&s
, " ");
619 trace_print_graph_duration(avg
, &s
);
620 trace_seq_puts(&s
, " ");
621 trace_print_graph_duration(stddev
, &s
);
622 trace_print_seq(m
, &s
);
626 mutex_unlock(&ftrace_profile_lock
);
631 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
633 struct ftrace_profile_page
*pg
;
635 pg
= stat
->pages
= stat
->start
;
638 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
643 memset(stat
->hash
, 0,
644 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
647 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
649 struct ftrace_profile_page
*pg
;
654 /* If we already allocated, do nothing */
658 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
662 #ifdef CONFIG_DYNAMIC_FTRACE
663 functions
= ftrace_update_tot_cnt
;
666 * We do not know the number of functions that exist because
667 * dynamic tracing is what counts them. With past experience
668 * we have around 20K functions. That should be more than enough.
669 * It is highly unlikely we will execute every function in
675 pg
= stat
->start
= stat
->pages
;
677 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
679 for (i
= 0; i
< pages
; i
++) {
680 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
691 unsigned long tmp
= (unsigned long)pg
;
703 static int ftrace_profile_init_cpu(int cpu
)
705 struct ftrace_profile_stat
*stat
;
708 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
711 /* If the profile is already created, simply reset it */
712 ftrace_profile_reset(stat
);
717 * We are profiling all functions, but usually only a few thousand
718 * functions are hit. We'll make a hash of 1024 items.
720 size
= FTRACE_PROFILE_HASH_SIZE
;
722 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
727 if (!ftrace_profile_bits
) {
730 for (; size
; size
>>= 1)
731 ftrace_profile_bits
++;
734 /* Preallocate the function profiling pages */
735 if (ftrace_profile_pages_init(stat
) < 0) {
744 static int ftrace_profile_init(void)
749 for_each_online_cpu(cpu
) {
750 ret
= ftrace_profile_init_cpu(cpu
);
758 /* interrupts must be disabled */
759 static struct ftrace_profile
*
760 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
762 struct ftrace_profile
*rec
;
763 struct hlist_head
*hhd
;
766 key
= hash_long(ip
, ftrace_profile_bits
);
767 hhd
= &stat
->hash
[key
];
769 if (hlist_empty(hhd
))
772 hlist_for_each_entry_rcu(rec
, hhd
, node
) {
780 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
781 struct ftrace_profile
*rec
)
785 key
= hash_long(rec
->ip
, ftrace_profile_bits
);
786 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
790 * The memory is already allocated, this simply finds a new record to use.
792 static struct ftrace_profile
*
793 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
795 struct ftrace_profile
*rec
= NULL
;
797 /* prevent recursion (from NMIs) */
798 if (atomic_inc_return(&stat
->disabled
) != 1)
802 * Try to find the function again since an NMI
803 * could have added it
805 rec
= ftrace_find_profiled_func(stat
, ip
);
809 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
810 if (!stat
->pages
->next
)
812 stat
->pages
= stat
->pages
->next
;
815 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
817 ftrace_add_profile(stat
, rec
);
820 atomic_dec(&stat
->disabled
);
826 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
827 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
829 struct ftrace_profile_stat
*stat
;
830 struct ftrace_profile
*rec
;
833 if (!ftrace_profile_enabled
)
836 local_irq_save(flags
);
838 stat
= &__get_cpu_var(ftrace_profile_stats
);
839 if (!stat
->hash
|| !ftrace_profile_enabled
)
842 rec
= ftrace_find_profiled_func(stat
, ip
);
844 rec
= ftrace_profile_alloc(stat
, ip
);
851 local_irq_restore(flags
);
854 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
855 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
857 function_profile_call(trace
->func
, 0, NULL
, NULL
);
861 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
863 struct ftrace_profile_stat
*stat
;
864 unsigned long long calltime
;
865 struct ftrace_profile
*rec
;
868 local_irq_save(flags
);
869 stat
= &__get_cpu_var(ftrace_profile_stats
);
870 if (!stat
->hash
|| !ftrace_profile_enabled
)
873 /* If the calltime was zero'd ignore it */
874 if (!trace
->calltime
)
877 calltime
= trace
->rettime
- trace
->calltime
;
879 if (!(trace_flags
& TRACE_ITER_GRAPH_TIME
)) {
882 index
= trace
->depth
;
884 /* Append this call time to the parent time to subtract */
886 current
->ret_stack
[index
- 1].subtime
+= calltime
;
888 if (current
->ret_stack
[index
].subtime
< calltime
)
889 calltime
-= current
->ret_stack
[index
].subtime
;
894 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
896 rec
->time
+= calltime
;
897 rec
->time_squared
+= calltime
* calltime
;
901 local_irq_restore(flags
);
904 static int register_ftrace_profiler(void)
906 return register_ftrace_graph(&profile_graph_return
,
907 &profile_graph_entry
);
910 static void unregister_ftrace_profiler(void)
912 unregister_ftrace_graph();
915 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
916 .func
= function_profile_call
,
917 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
,
920 static int register_ftrace_profiler(void)
922 return register_ftrace_function(&ftrace_profile_ops
);
925 static void unregister_ftrace_profiler(void)
927 unregister_ftrace_function(&ftrace_profile_ops
);
929 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
932 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
933 size_t cnt
, loff_t
*ppos
)
938 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
944 mutex_lock(&ftrace_profile_lock
);
945 if (ftrace_profile_enabled
^ val
) {
947 ret
= ftrace_profile_init();
953 ret
= register_ftrace_profiler();
958 ftrace_profile_enabled
= 1;
960 ftrace_profile_enabled
= 0;
962 * unregister_ftrace_profiler calls stop_machine
963 * so this acts like an synchronize_sched.
965 unregister_ftrace_profiler();
969 mutex_unlock(&ftrace_profile_lock
);
977 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
978 size_t cnt
, loff_t
*ppos
)
980 char buf
[64]; /* big enough to hold a number */
983 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
984 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
987 static const struct file_operations ftrace_profile_fops
= {
988 .open
= tracing_open_generic
,
989 .read
= ftrace_profile_read
,
990 .write
= ftrace_profile_write
,
991 .llseek
= default_llseek
,
994 /* used to initialize the real stat files */
995 static struct tracer_stat function_stats __initdata
= {
997 .stat_start
= function_stat_start
,
998 .stat_next
= function_stat_next
,
999 .stat_cmp
= function_stat_cmp
,
1000 .stat_headers
= function_stat_headers
,
1001 .stat_show
= function_stat_show
1004 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1006 struct ftrace_profile_stat
*stat
;
1007 struct dentry
*entry
;
1012 for_each_possible_cpu(cpu
) {
1013 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1015 /* allocate enough for function name + cpu number */
1016 name
= kmalloc(32, GFP_KERNEL
);
1019 * The files created are permanent, if something happens
1020 * we still do not free memory.
1023 "Could not allocate stat file for cpu %d\n",
1027 stat
->stat
= function_stats
;
1028 snprintf(name
, 32, "function%d", cpu
);
1029 stat
->stat
.name
= name
;
1030 ret
= register_stat_tracer(&stat
->stat
);
1033 "Could not register function stat for cpu %d\n",
1040 entry
= debugfs_create_file("function_profile_enabled", 0644,
1041 d_tracer
, NULL
, &ftrace_profile_fops
);
1043 pr_warning("Could not create debugfs "
1044 "'function_profile_enabled' entry\n");
1047 #else /* CONFIG_FUNCTION_PROFILER */
1048 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1051 #endif /* CONFIG_FUNCTION_PROFILER */
1053 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1056 ftrace_filter_lseek(struct file
*file
, loff_t offset
, int whence
)
1060 if (file
->f_mode
& FMODE_READ
)
1061 ret
= seq_lseek(file
, offset
, whence
);
1063 file
->f_pos
= ret
= 1;
1068 #ifdef CONFIG_DYNAMIC_FTRACE
1070 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1071 # error Dynamic ftrace depends on MCOUNT_RECORD
1074 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1076 struct ftrace_func_probe
{
1077 struct hlist_node node
;
1078 struct ftrace_probe_ops
*ops
;
1079 unsigned long flags
;
1082 struct rcu_head rcu
;
1085 struct ftrace_func_entry
{
1086 struct hlist_node hlist
;
1090 struct ftrace_hash
{
1091 unsigned long size_bits
;
1092 struct hlist_head
*buckets
;
1093 unsigned long count
;
1094 struct rcu_head rcu
;
1098 * We make these constant because no one should touch them,
1099 * but they are used as the default "empty hash", to avoid allocating
1100 * it all the time. These are in a read only section such that if
1101 * anyone does try to modify it, it will cause an exception.
1103 static const struct hlist_head empty_buckets
[1];
1104 static const struct ftrace_hash empty_hash
= {
1105 .buckets
= (struct hlist_head
*)empty_buckets
,
1107 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1109 static struct ftrace_ops global_ops
= {
1110 .func
= ftrace_stub
,
1111 .notrace_hash
= EMPTY_HASH
,
1112 .filter_hash
= EMPTY_HASH
,
1113 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
,
1116 static DEFINE_MUTEX(ftrace_regex_lock
);
1118 struct ftrace_page
{
1119 struct ftrace_page
*next
;
1120 struct dyn_ftrace
*records
;
1125 static struct ftrace_page
*ftrace_new_pgs
;
1127 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1128 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1130 /* estimate from running different kernels */
1131 #define NR_TO_INIT 10000
1133 static struct ftrace_page
*ftrace_pages_start
;
1134 static struct ftrace_page
*ftrace_pages
;
1136 static bool ftrace_hash_empty(struct ftrace_hash
*hash
)
1138 return !hash
|| !hash
->count
;
1141 static struct ftrace_func_entry
*
1142 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1145 struct ftrace_func_entry
*entry
;
1146 struct hlist_head
*hhd
;
1148 if (ftrace_hash_empty(hash
))
1151 if (hash
->size_bits
> 0)
1152 key
= hash_long(ip
, hash
->size_bits
);
1156 hhd
= &hash
->buckets
[key
];
1158 hlist_for_each_entry_rcu(entry
, hhd
, hlist
) {
1159 if (entry
->ip
== ip
)
1165 static void __add_hash_entry(struct ftrace_hash
*hash
,
1166 struct ftrace_func_entry
*entry
)
1168 struct hlist_head
*hhd
;
1171 if (hash
->size_bits
)
1172 key
= hash_long(entry
->ip
, hash
->size_bits
);
1176 hhd
= &hash
->buckets
[key
];
1177 hlist_add_head(&entry
->hlist
, hhd
);
1181 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1183 struct ftrace_func_entry
*entry
;
1185 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1190 __add_hash_entry(hash
, entry
);
1196 free_hash_entry(struct ftrace_hash
*hash
,
1197 struct ftrace_func_entry
*entry
)
1199 hlist_del(&entry
->hlist
);
1205 remove_hash_entry(struct ftrace_hash
*hash
,
1206 struct ftrace_func_entry
*entry
)
1208 hlist_del(&entry
->hlist
);
1212 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1214 struct hlist_head
*hhd
;
1215 struct hlist_node
*tn
;
1216 struct ftrace_func_entry
*entry
;
1217 int size
= 1 << hash
->size_bits
;
1223 for (i
= 0; i
< size
; i
++) {
1224 hhd
= &hash
->buckets
[i
];
1225 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1226 free_hash_entry(hash
, entry
);
1228 FTRACE_WARN_ON(hash
->count
);
1231 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1233 if (!hash
|| hash
== EMPTY_HASH
)
1235 ftrace_hash_clear(hash
);
1236 kfree(hash
->buckets
);
1240 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1242 struct ftrace_hash
*hash
;
1244 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1245 free_ftrace_hash(hash
);
1248 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1250 if (!hash
|| hash
== EMPTY_HASH
)
1252 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1255 void ftrace_free_filter(struct ftrace_ops
*ops
)
1257 free_ftrace_hash(ops
->filter_hash
);
1258 free_ftrace_hash(ops
->notrace_hash
);
1261 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1263 struct ftrace_hash
*hash
;
1266 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1270 size
= 1 << size_bits
;
1271 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1273 if (!hash
->buckets
) {
1278 hash
->size_bits
= size_bits
;
1283 static struct ftrace_hash
*
1284 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1286 struct ftrace_func_entry
*entry
;
1287 struct ftrace_hash
*new_hash
;
1292 new_hash
= alloc_ftrace_hash(size_bits
);
1297 if (ftrace_hash_empty(hash
))
1300 size
= 1 << hash
->size_bits
;
1301 for (i
= 0; i
< size
; i
++) {
1302 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1303 ret
= add_hash_entry(new_hash
, entry
->ip
);
1309 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1314 free_ftrace_hash(new_hash
);
1319 ftrace_hash_rec_disable(struct ftrace_ops
*ops
, int filter_hash
);
1321 ftrace_hash_rec_enable(struct ftrace_ops
*ops
, int filter_hash
);
1324 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1325 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1327 struct ftrace_func_entry
*entry
;
1328 struct hlist_node
*tn
;
1329 struct hlist_head
*hhd
;
1330 struct ftrace_hash
*old_hash
;
1331 struct ftrace_hash
*new_hash
;
1333 int size
= src
->count
;
1339 * Remove the current set, update the hash and add
1342 ftrace_hash_rec_disable(ops
, enable
);
1345 * If the new source is empty, just free dst and assign it
1349 free_ftrace_hash_rcu(*dst
);
1350 rcu_assign_pointer(*dst
, EMPTY_HASH
);
1351 /* still need to update the function records */
1357 * Make the hash size about 1/2 the # found
1359 for (size
/= 2; size
; size
>>= 1)
1362 /* Don't allocate too much */
1363 if (bits
> FTRACE_HASH_MAX_BITS
)
1364 bits
= FTRACE_HASH_MAX_BITS
;
1367 new_hash
= alloc_ftrace_hash(bits
);
1371 size
= 1 << src
->size_bits
;
1372 for (i
= 0; i
< size
; i
++) {
1373 hhd
= &src
->buckets
[i
];
1374 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1376 key
= hash_long(entry
->ip
, bits
);
1379 remove_hash_entry(src
, entry
);
1380 __add_hash_entry(new_hash
, entry
);
1385 rcu_assign_pointer(*dst
, new_hash
);
1386 free_ftrace_hash_rcu(old_hash
);
1391 * Enable regardless of ret:
1392 * On success, we enable the new hash.
1393 * On failure, we re-enable the original hash.
1395 ftrace_hash_rec_enable(ops
, enable
);
1401 * Test the hashes for this ops to see if we want to call
1402 * the ops->func or not.
1404 * It's a match if the ip is in the ops->filter_hash or
1405 * the filter_hash does not exist or is empty,
1407 * the ip is not in the ops->notrace_hash.
1409 * This needs to be called with preemption disabled as
1410 * the hashes are freed with call_rcu_sched().
1413 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
)
1415 struct ftrace_hash
*filter_hash
;
1416 struct ftrace_hash
*notrace_hash
;
1419 filter_hash
= rcu_dereference_raw(ops
->filter_hash
);
1420 notrace_hash
= rcu_dereference_raw(ops
->notrace_hash
);
1422 if ((ftrace_hash_empty(filter_hash
) ||
1423 ftrace_lookup_ip(filter_hash
, ip
)) &&
1424 (ftrace_hash_empty(notrace_hash
) ||
1425 !ftrace_lookup_ip(notrace_hash
, ip
)))
1434 * This is a double for. Do not use 'break' to break out of the loop,
1435 * you must use a goto.
1437 #define do_for_each_ftrace_rec(pg, rec) \
1438 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1440 for (_____i = 0; _____i < pg->index; _____i++) { \
1441 rec = &pg->records[_____i];
1443 #define while_for_each_ftrace_rec() \
1448 static int ftrace_cmp_recs(const void *a
, const void *b
)
1450 const struct dyn_ftrace
*key
= a
;
1451 const struct dyn_ftrace
*rec
= b
;
1453 if (key
->flags
< rec
->ip
)
1455 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1460 static unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1462 struct ftrace_page
*pg
;
1463 struct dyn_ftrace
*rec
;
1464 struct dyn_ftrace key
;
1467 key
.flags
= end
; /* overload flags, as it is unsigned long */
1469 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1470 if (end
< pg
->records
[0].ip
||
1471 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1473 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1474 sizeof(struct dyn_ftrace
),
1484 * ftrace_location - return true if the ip giving is a traced location
1485 * @ip: the instruction pointer to check
1487 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1488 * That is, the instruction that is either a NOP or call to
1489 * the function tracer. It checks the ftrace internal tables to
1490 * determine if the address belongs or not.
1492 unsigned long ftrace_location(unsigned long ip
)
1494 return ftrace_location_range(ip
, ip
);
1498 * ftrace_text_reserved - return true if range contains an ftrace location
1499 * @start: start of range to search
1500 * @end: end of range to search (inclusive). @end points to the last byte to check.
1502 * Returns 1 if @start and @end contains a ftrace location.
1503 * That is, the instruction that is either a NOP or call to
1504 * the function tracer. It checks the ftrace internal tables to
1505 * determine if the address belongs or not.
1507 int ftrace_text_reserved(void *start
, void *end
)
1511 ret
= ftrace_location_range((unsigned long)start
,
1512 (unsigned long)end
);
1517 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1521 struct ftrace_hash
*hash
;
1522 struct ftrace_hash
*other_hash
;
1523 struct ftrace_page
*pg
;
1524 struct dyn_ftrace
*rec
;
1528 /* Only update if the ops has been registered */
1529 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1533 * In the filter_hash case:
1534 * If the count is zero, we update all records.
1535 * Otherwise we just update the items in the hash.
1537 * In the notrace_hash case:
1538 * We enable the update in the hash.
1539 * As disabling notrace means enabling the tracing,
1540 * and enabling notrace means disabling, the inc variable
1544 hash
= ops
->filter_hash
;
1545 other_hash
= ops
->notrace_hash
;
1546 if (ftrace_hash_empty(hash
))
1550 hash
= ops
->notrace_hash
;
1551 other_hash
= ops
->filter_hash
;
1553 * If the notrace hash has no items,
1554 * then there's nothing to do.
1556 if (ftrace_hash_empty(hash
))
1560 do_for_each_ftrace_rec(pg
, rec
) {
1561 int in_other_hash
= 0;
1567 * Only the filter_hash affects all records.
1568 * Update if the record is not in the notrace hash.
1570 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1573 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1574 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1579 if (filter_hash
&& in_hash
&& !in_other_hash
)
1581 else if (!filter_hash
&& in_hash
&&
1582 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1590 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == FTRACE_REF_MAX
))
1593 * If any ops wants regs saved for this function
1594 * then all ops will get saved regs.
1596 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1597 rec
->flags
|= FTRACE_FL_REGS
;
1599 if (FTRACE_WARN_ON((rec
->flags
& ~FTRACE_FL_MASK
) == 0))
1604 /* Shortcut, if we handled all records, we are done. */
1605 if (!all
&& count
== hash
->count
)
1607 } while_for_each_ftrace_rec();
1610 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1613 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1616 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1619 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1622 static void print_ip_ins(const char *fmt
, unsigned char *p
)
1626 printk(KERN_CONT
"%s", fmt
);
1628 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1629 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1633 * ftrace_bug - report and shutdown function tracer
1634 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1635 * @ip: The address that failed
1637 * The arch code that enables or disables the function tracing
1638 * can call ftrace_bug() when it has detected a problem in
1639 * modifying the code. @failed should be one of either:
1640 * EFAULT - if the problem happens on reading the @ip address
1641 * EINVAL - if what is read at @ip is not what was expected
1642 * EPERM - if the problem happens on writting to the @ip address
1644 void ftrace_bug(int failed
, unsigned long ip
)
1648 FTRACE_WARN_ON_ONCE(1);
1649 pr_info("ftrace faulted on modifying ");
1653 FTRACE_WARN_ON_ONCE(1);
1654 pr_info("ftrace failed to modify ");
1656 print_ip_ins(" actual: ", (unsigned char *)ip
);
1657 printk(KERN_CONT
"\n");
1660 FTRACE_WARN_ON_ONCE(1);
1661 pr_info("ftrace faulted on writing ");
1665 FTRACE_WARN_ON_ONCE(1);
1666 pr_info("ftrace faulted on unknown error ");
1671 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
1673 unsigned long flag
= 0UL;
1676 * If we are updating calls:
1678 * If the record has a ref count, then we need to enable it
1679 * because someone is using it.
1681 * Otherwise we make sure its disabled.
1683 * If we are disabling calls, then disable all records that
1686 if (enable
&& (rec
->flags
& ~FTRACE_FL_MASK
))
1687 flag
= FTRACE_FL_ENABLED
;
1690 * If enabling and the REGS flag does not match the REGS_EN, then
1691 * do not ignore this record. Set flags to fail the compare against
1695 (!(rec
->flags
& FTRACE_FL_REGS
) != !(rec
->flags
& FTRACE_FL_REGS_EN
)))
1696 flag
|= FTRACE_FL_REGS
;
1698 /* If the state of this record hasn't changed, then do nothing */
1699 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
1700 return FTRACE_UPDATE_IGNORE
;
1703 /* Save off if rec is being enabled (for return value) */
1704 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
1707 rec
->flags
|= FTRACE_FL_ENABLED
;
1708 if (flag
& FTRACE_FL_REGS
) {
1709 if (rec
->flags
& FTRACE_FL_REGS
)
1710 rec
->flags
|= FTRACE_FL_REGS_EN
;
1712 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
1717 * If this record is being updated from a nop, then
1718 * return UPDATE_MAKE_CALL.
1719 * Otherwise, if the EN flag is set, then return
1720 * UPDATE_MODIFY_CALL_REGS to tell the caller to convert
1721 * from the non-save regs, to a save regs function.
1723 * return UPDATE_MODIFY_CALL to tell the caller to convert
1724 * from the save regs, to a non-save regs function.
1726 if (flag
& FTRACE_FL_ENABLED
)
1727 return FTRACE_UPDATE_MAKE_CALL
;
1728 else if (rec
->flags
& FTRACE_FL_REGS_EN
)
1729 return FTRACE_UPDATE_MODIFY_CALL_REGS
;
1731 return FTRACE_UPDATE_MODIFY_CALL
;
1735 /* If there's no more users, clear all flags */
1736 if (!(rec
->flags
& ~FTRACE_FL_MASK
))
1739 /* Just disable the record (keep REGS state) */
1740 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1743 return FTRACE_UPDATE_MAKE_NOP
;
1747 * ftrace_update_record, set a record that now is tracing or not
1748 * @rec: the record to update
1749 * @enable: set to 1 if the record is tracing, zero to force disable
1751 * The records that represent all functions that can be traced need
1752 * to be updated when tracing has been enabled.
1754 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
1756 return ftrace_check_record(rec
, enable
, 1);
1760 * ftrace_test_record, check if the record has been enabled or not
1761 * @rec: the record to test
1762 * @enable: set to 1 to check if enabled, 0 if it is disabled
1764 * The arch code may need to test if a record is already set to
1765 * tracing to determine how to modify the function code that it
1768 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
1770 return ftrace_check_record(rec
, enable
, 0);
1774 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
1776 unsigned long ftrace_old_addr
;
1777 unsigned long ftrace_addr
;
1780 ret
= ftrace_update_record(rec
, enable
);
1782 if (rec
->flags
& FTRACE_FL_REGS
)
1783 ftrace_addr
= (unsigned long)FTRACE_REGS_ADDR
;
1785 ftrace_addr
= (unsigned long)FTRACE_ADDR
;
1788 case FTRACE_UPDATE_IGNORE
:
1791 case FTRACE_UPDATE_MAKE_CALL
:
1792 return ftrace_make_call(rec
, ftrace_addr
);
1794 case FTRACE_UPDATE_MAKE_NOP
:
1795 return ftrace_make_nop(NULL
, rec
, ftrace_addr
);
1797 case FTRACE_UPDATE_MODIFY_CALL_REGS
:
1798 case FTRACE_UPDATE_MODIFY_CALL
:
1799 if (rec
->flags
& FTRACE_FL_REGS
)
1800 ftrace_old_addr
= (unsigned long)FTRACE_ADDR
;
1802 ftrace_old_addr
= (unsigned long)FTRACE_REGS_ADDR
;
1804 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
1807 return -1; /* unknow ftrace bug */
1810 void __weak
ftrace_replace_code(int enable
)
1812 struct dyn_ftrace
*rec
;
1813 struct ftrace_page
*pg
;
1816 if (unlikely(ftrace_disabled
))
1819 do_for_each_ftrace_rec(pg
, rec
) {
1820 failed
= __ftrace_replace_code(rec
, enable
);
1822 ftrace_bug(failed
, rec
->ip
);
1823 /* Stop processing */
1826 } while_for_each_ftrace_rec();
1829 struct ftrace_rec_iter
{
1830 struct ftrace_page
*pg
;
1835 * ftrace_rec_iter_start, start up iterating over traced functions
1837 * Returns an iterator handle that is used to iterate over all
1838 * the records that represent address locations where functions
1841 * May return NULL if no records are available.
1843 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
1846 * We only use a single iterator.
1847 * Protected by the ftrace_lock mutex.
1849 static struct ftrace_rec_iter ftrace_rec_iter
;
1850 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
1852 iter
->pg
= ftrace_pages_start
;
1855 /* Could have empty pages */
1856 while (iter
->pg
&& !iter
->pg
->index
)
1857 iter
->pg
= iter
->pg
->next
;
1866 * ftrace_rec_iter_next, get the next record to process.
1867 * @iter: The handle to the iterator.
1869 * Returns the next iterator after the given iterator @iter.
1871 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
1875 if (iter
->index
>= iter
->pg
->index
) {
1876 iter
->pg
= iter
->pg
->next
;
1879 /* Could have empty pages */
1880 while (iter
->pg
&& !iter
->pg
->index
)
1881 iter
->pg
= iter
->pg
->next
;
1891 * ftrace_rec_iter_record, get the record at the iterator location
1892 * @iter: The current iterator location
1894 * Returns the record that the current @iter is at.
1896 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
1898 return &iter
->pg
->records
[iter
->index
];
1902 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
1909 if (unlikely(ftrace_disabled
))
1912 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
1914 ftrace_bug(ret
, ip
);
1921 * archs can override this function if they must do something
1922 * before the modifying code is performed.
1924 int __weak
ftrace_arch_code_modify_prepare(void)
1930 * archs can override this function if they must do something
1931 * after the modifying code is performed.
1933 int __weak
ftrace_arch_code_modify_post_process(void)
1938 void ftrace_modify_all_code(int command
)
1940 if (command
& FTRACE_UPDATE_CALLS
)
1941 ftrace_replace_code(1);
1942 else if (command
& FTRACE_DISABLE_CALLS
)
1943 ftrace_replace_code(0);
1945 if (command
& FTRACE_UPDATE_TRACE_FUNC
)
1946 ftrace_update_ftrace_func(ftrace_trace_function
);
1948 if (command
& FTRACE_START_FUNC_RET
)
1949 ftrace_enable_ftrace_graph_caller();
1950 else if (command
& FTRACE_STOP_FUNC_RET
)
1951 ftrace_disable_ftrace_graph_caller();
1954 static int __ftrace_modify_code(void *data
)
1956 int *command
= data
;
1958 ftrace_modify_all_code(*command
);
1964 * ftrace_run_stop_machine, go back to the stop machine method
1965 * @command: The command to tell ftrace what to do
1967 * If an arch needs to fall back to the stop machine method, the
1968 * it can call this function.
1970 void ftrace_run_stop_machine(int command
)
1972 stop_machine(__ftrace_modify_code
, &command
, NULL
);
1976 * arch_ftrace_update_code, modify the code to trace or not trace
1977 * @command: The command that needs to be done
1979 * Archs can override this function if it does not need to
1980 * run stop_machine() to modify code.
1982 void __weak
arch_ftrace_update_code(int command
)
1984 ftrace_run_stop_machine(command
);
1987 static void ftrace_run_update_code(int command
)
1991 ret
= ftrace_arch_code_modify_prepare();
1992 FTRACE_WARN_ON(ret
);
1996 * Do not call function tracer while we update the code.
1997 * We are in stop machine.
1999 function_trace_stop
++;
2002 * By default we use stop_machine() to modify the code.
2003 * But archs can do what ever they want as long as it
2004 * is safe. The stop_machine() is the safest, but also
2005 * produces the most overhead.
2007 arch_ftrace_update_code(command
);
2009 function_trace_stop
--;
2011 ret
= ftrace_arch_code_modify_post_process();
2012 FTRACE_WARN_ON(ret
);
2015 static ftrace_func_t saved_ftrace_func
;
2016 static int ftrace_start_up
;
2017 static int global_start_up
;
2019 static void ftrace_startup_enable(int command
)
2021 if (saved_ftrace_func
!= ftrace_trace_function
) {
2022 saved_ftrace_func
= ftrace_trace_function
;
2023 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2026 if (!command
|| !ftrace_enabled
)
2029 ftrace_run_update_code(command
);
2032 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2034 bool hash_enable
= true;
2036 if (unlikely(ftrace_disabled
))
2040 command
|= FTRACE_UPDATE_CALLS
;
2042 /* ops marked global share the filter hashes */
2043 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
2045 /* Don't update hash if global is already set */
2046 if (global_start_up
)
2047 hash_enable
= false;
2051 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
2053 ftrace_hash_rec_enable(ops
, 1);
2055 ftrace_startup_enable(command
);
2060 static void ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2062 bool hash_disable
= true;
2064 if (unlikely(ftrace_disabled
))
2069 * Just warn in case of unbalance, no need to kill ftrace, it's not
2070 * critical but the ftrace_call callers may be never nopped again after
2071 * further ftrace uses.
2073 WARN_ON_ONCE(ftrace_start_up
< 0);
2075 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
) {
2078 WARN_ON_ONCE(global_start_up
< 0);
2079 /* Don't update hash if global still has users */
2080 if (global_start_up
) {
2081 WARN_ON_ONCE(!ftrace_start_up
);
2082 hash_disable
= false;
2087 ftrace_hash_rec_disable(ops
, 1);
2089 if (ops
!= &global_ops
|| !global_start_up
)
2090 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2092 command
|= FTRACE_UPDATE_CALLS
;
2094 if (saved_ftrace_func
!= ftrace_trace_function
) {
2095 saved_ftrace_func
= ftrace_trace_function
;
2096 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2099 if (!command
|| !ftrace_enabled
)
2102 ftrace_run_update_code(command
);
2105 static void ftrace_startup_sysctl(void)
2107 if (unlikely(ftrace_disabled
))
2110 /* Force update next time */
2111 saved_ftrace_func
= NULL
;
2112 /* ftrace_start_up is true if we want ftrace running */
2113 if (ftrace_start_up
)
2114 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
2117 static void ftrace_shutdown_sysctl(void)
2119 if (unlikely(ftrace_disabled
))
2122 /* ftrace_start_up is true if ftrace is running */
2123 if (ftrace_start_up
)
2124 ftrace_run_update_code(FTRACE_DISABLE_CALLS
);
2127 static cycle_t ftrace_update_time
;
2128 static unsigned long ftrace_update_cnt
;
2129 unsigned long ftrace_update_tot_cnt
;
2131 static int ops_traces_mod(struct ftrace_ops
*ops
)
2133 struct ftrace_hash
*hash
;
2135 hash
= ops
->filter_hash
;
2136 return ftrace_hash_empty(hash
);
2139 static int ftrace_update_code(struct module
*mod
)
2141 struct ftrace_page
*pg
;
2142 struct dyn_ftrace
*p
;
2143 cycle_t start
, stop
;
2144 unsigned long ref
= 0;
2148 * When adding a module, we need to check if tracers are
2149 * currently enabled and if they are set to trace all functions.
2150 * If they are, we need to enable the module functions as well
2151 * as update the reference counts for those function records.
2154 struct ftrace_ops
*ops
;
2156 for (ops
= ftrace_ops_list
;
2157 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2158 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
&&
2159 ops_traces_mod(ops
))
2164 start
= ftrace_now(raw_smp_processor_id());
2165 ftrace_update_cnt
= 0;
2167 for (pg
= ftrace_new_pgs
; pg
; pg
= pg
->next
) {
2169 for (i
= 0; i
< pg
->index
; i
++) {
2170 /* If something went wrong, bail without enabling anything */
2171 if (unlikely(ftrace_disabled
))
2174 p
= &pg
->records
[i
];
2178 * Do the initial record conversion from mcount jump
2179 * to the NOP instructions.
2181 if (!ftrace_code_disable(mod
, p
))
2184 ftrace_update_cnt
++;
2187 * If the tracing is enabled, go ahead and enable the record.
2189 * The reason not to enable the record immediatelly is the
2190 * inherent check of ftrace_make_nop/ftrace_make_call for
2191 * correct previous instructions. Making first the NOP
2192 * conversion puts the module to the correct state, thus
2193 * passing the ftrace_make_call check.
2195 if (ftrace_start_up
&& ref
) {
2196 int failed
= __ftrace_replace_code(p
, 1);
2198 ftrace_bug(failed
, p
->ip
);
2203 ftrace_new_pgs
= NULL
;
2205 stop
= ftrace_now(raw_smp_processor_id());
2206 ftrace_update_time
= stop
- start
;
2207 ftrace_update_tot_cnt
+= ftrace_update_cnt
;
2212 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2217 if (WARN_ON(!count
))
2220 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2223 * We want to fill as much as possible. No more than a page
2226 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2230 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2233 /* if we can't allocate this size, try something smaller */
2240 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2249 static struct ftrace_page
*
2250 ftrace_allocate_pages(unsigned long num_to_init
)
2252 struct ftrace_page
*start_pg
;
2253 struct ftrace_page
*pg
;
2260 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2265 * Try to allocate as much as possible in one continues
2266 * location that fills in all of the space. We want to
2267 * waste as little space as possible.
2270 cnt
= ftrace_allocate_records(pg
, num_to_init
);
2278 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2289 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
2290 free_pages((unsigned long)pg
->records
, order
);
2291 start_pg
= pg
->next
;
2295 pr_info("ftrace: FAILED to allocate memory for functions\n");
2299 static int __init
ftrace_dyn_table_alloc(unsigned long num_to_init
)
2304 pr_info("ftrace: No functions to be traced?\n");
2308 cnt
= num_to_init
/ ENTRIES_PER_PAGE
;
2309 pr_info("ftrace: allocating %ld entries in %d pages\n",
2310 num_to_init
, cnt
+ 1);
2315 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2317 struct ftrace_iterator
{
2320 struct ftrace_page
*pg
;
2321 struct dyn_ftrace
*func
;
2322 struct ftrace_func_probe
*probe
;
2323 struct trace_parser parser
;
2324 struct ftrace_hash
*hash
;
2325 struct ftrace_ops
*ops
;
2332 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
2334 struct ftrace_iterator
*iter
= m
->private;
2335 struct hlist_node
*hnd
= NULL
;
2336 struct hlist_head
*hhd
;
2342 hnd
= &iter
->probe
->node
;
2344 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
2347 hhd
= &ftrace_func_hash
[iter
->hidx
];
2349 if (hlist_empty(hhd
)) {
2365 if (WARN_ON_ONCE(!hnd
))
2368 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
2373 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
2375 struct ftrace_iterator
*iter
= m
->private;
2379 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
2382 if (iter
->func_pos
> *pos
)
2386 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
2387 p
= t_hash_next(m
, &l
);
2394 /* Only set this if we have an item */
2395 iter
->flags
|= FTRACE_ITER_HASH
;
2401 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
2403 struct ftrace_func_probe
*rec
;
2406 if (WARN_ON_ONCE(!rec
))
2409 if (rec
->ops
->print
)
2410 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
2412 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
2415 seq_printf(m
, ":%p", rec
->data
);
2422 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2424 struct ftrace_iterator
*iter
= m
->private;
2425 struct ftrace_ops
*ops
= iter
->ops
;
2426 struct dyn_ftrace
*rec
= NULL
;
2428 if (unlikely(ftrace_disabled
))
2431 if (iter
->flags
& FTRACE_ITER_HASH
)
2432 return t_hash_next(m
, pos
);
2435 iter
->pos
= iter
->func_pos
= *pos
;
2437 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
2438 return t_hash_start(m
, pos
);
2441 if (iter
->idx
>= iter
->pg
->index
) {
2442 if (iter
->pg
->next
) {
2443 iter
->pg
= iter
->pg
->next
;
2448 rec
= &iter
->pg
->records
[iter
->idx
++];
2449 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
2450 !(ftrace_lookup_ip(ops
->filter_hash
, rec
->ip
))) ||
2452 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
2453 !ftrace_lookup_ip(ops
->notrace_hash
, rec
->ip
)) ||
2455 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
2456 !(rec
->flags
& ~FTRACE_FL_MASK
))) {
2464 return t_hash_start(m
, pos
);
2471 static void reset_iter_read(struct ftrace_iterator
*iter
)
2475 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
2478 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2480 struct ftrace_iterator
*iter
= m
->private;
2481 struct ftrace_ops
*ops
= iter
->ops
;
2485 mutex_lock(&ftrace_lock
);
2487 if (unlikely(ftrace_disabled
))
2491 * If an lseek was done, then reset and start from beginning.
2493 if (*pos
< iter
->pos
)
2494 reset_iter_read(iter
);
2497 * For set_ftrace_filter reading, if we have the filter
2498 * off, we can short cut and just print out that all
2499 * functions are enabled.
2501 if (iter
->flags
& FTRACE_ITER_FILTER
&&
2502 ftrace_hash_empty(ops
->filter_hash
)) {
2504 return t_hash_start(m
, pos
);
2505 iter
->flags
|= FTRACE_ITER_PRINTALL
;
2506 /* reset in case of seek/pread */
2507 iter
->flags
&= ~FTRACE_ITER_HASH
;
2511 if (iter
->flags
& FTRACE_ITER_HASH
)
2512 return t_hash_start(m
, pos
);
2515 * Unfortunately, we need to restart at ftrace_pages_start
2516 * every time we let go of the ftrace_mutex. This is because
2517 * those pointers can change without the lock.
2519 iter
->pg
= ftrace_pages_start
;
2521 for (l
= 0; l
<= *pos
; ) {
2522 p
= t_next(m
, p
, &l
);
2528 return t_hash_start(m
, pos
);
2533 static void t_stop(struct seq_file
*m
, void *p
)
2535 mutex_unlock(&ftrace_lock
);
2538 static int t_show(struct seq_file
*m
, void *v
)
2540 struct ftrace_iterator
*iter
= m
->private;
2541 struct dyn_ftrace
*rec
;
2543 if (iter
->flags
& FTRACE_ITER_HASH
)
2544 return t_hash_show(m
, iter
);
2546 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
2547 seq_printf(m
, "#### all functions enabled ####\n");
2556 seq_printf(m
, "%ps", (void *)rec
->ip
);
2557 if (iter
->flags
& FTRACE_ITER_ENABLED
)
2558 seq_printf(m
, " (%ld)%s",
2559 rec
->flags
& ~FTRACE_FL_MASK
,
2560 rec
->flags
& FTRACE_FL_REGS
? " R" : "");
2561 seq_printf(m
, "\n");
2566 static const struct seq_operations show_ftrace_seq_ops
= {
2574 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
2576 struct ftrace_iterator
*iter
;
2578 if (unlikely(ftrace_disabled
))
2581 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2583 iter
->pg
= ftrace_pages_start
;
2584 iter
->ops
= &global_ops
;
2587 return iter
? 0 : -ENOMEM
;
2591 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
2593 struct ftrace_iterator
*iter
;
2595 if (unlikely(ftrace_disabled
))
2598 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2600 iter
->pg
= ftrace_pages_start
;
2601 iter
->flags
= FTRACE_ITER_ENABLED
;
2602 iter
->ops
= &global_ops
;
2605 return iter
? 0 : -ENOMEM
;
2608 static void ftrace_filter_reset(struct ftrace_hash
*hash
)
2610 mutex_lock(&ftrace_lock
);
2611 ftrace_hash_clear(hash
);
2612 mutex_unlock(&ftrace_lock
);
2616 * ftrace_regex_open - initialize function tracer filter files
2617 * @ops: The ftrace_ops that hold the hash filters
2618 * @flag: The type of filter to process
2619 * @inode: The inode, usually passed in to your open routine
2620 * @file: The file, usually passed in to your open routine
2622 * ftrace_regex_open() initializes the filter files for the
2623 * @ops. Depending on @flag it may process the filter hash or
2624 * the notrace hash of @ops. With this called from the open
2625 * routine, you can use ftrace_filter_write() for the write
2626 * routine if @flag has FTRACE_ITER_FILTER set, or
2627 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2628 * ftrace_filter_lseek() should be used as the lseek routine, and
2629 * release must call ftrace_regex_release().
2632 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
2633 struct inode
*inode
, struct file
*file
)
2635 struct ftrace_iterator
*iter
;
2636 struct ftrace_hash
*hash
;
2639 if (unlikely(ftrace_disabled
))
2642 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2646 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
2651 if (flag
& FTRACE_ITER_NOTRACE
)
2652 hash
= ops
->notrace_hash
;
2654 hash
= ops
->filter_hash
;
2659 if (file
->f_mode
& FMODE_WRITE
) {
2660 mutex_lock(&ftrace_lock
);
2661 iter
->hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, hash
);
2662 mutex_unlock(&ftrace_lock
);
2665 trace_parser_put(&iter
->parser
);
2671 mutex_lock(&ftrace_regex_lock
);
2673 if ((file
->f_mode
& FMODE_WRITE
) &&
2674 (file
->f_flags
& O_TRUNC
))
2675 ftrace_filter_reset(iter
->hash
);
2677 if (file
->f_mode
& FMODE_READ
) {
2678 iter
->pg
= ftrace_pages_start
;
2680 ret
= seq_open(file
, &show_ftrace_seq_ops
);
2682 struct seq_file
*m
= file
->private_data
;
2686 free_ftrace_hash(iter
->hash
);
2687 trace_parser_put(&iter
->parser
);
2691 file
->private_data
= iter
;
2692 mutex_unlock(&ftrace_regex_lock
);
2698 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
2700 return ftrace_regex_open(&global_ops
,
2701 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
2706 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
2708 return ftrace_regex_open(&global_ops
, FTRACE_ITER_NOTRACE
,
2712 static int ftrace_match(char *str
, char *regex
, int len
, int type
)
2719 if (strcmp(str
, regex
) == 0)
2722 case MATCH_FRONT_ONLY
:
2723 if (strncmp(str
, regex
, len
) == 0)
2726 case MATCH_MIDDLE_ONLY
:
2727 if (strstr(str
, regex
))
2730 case MATCH_END_ONLY
:
2732 if (slen
>= len
&& memcmp(str
+ slen
- len
, regex
, len
) == 0)
2741 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int not)
2743 struct ftrace_func_entry
*entry
;
2746 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
2748 /* Do nothing if it doesn't exist */
2752 free_hash_entry(hash
, entry
);
2754 /* Do nothing if it exists */
2758 ret
= add_hash_entry(hash
, rec
->ip
);
2764 ftrace_match_record(struct dyn_ftrace
*rec
, char *mod
,
2765 char *regex
, int len
, int type
)
2767 char str
[KSYM_SYMBOL_LEN
];
2770 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
2773 /* module lookup requires matching the module */
2774 if (!modname
|| strcmp(modname
, mod
))
2777 /* blank search means to match all funcs in the mod */
2782 return ftrace_match(str
, regex
, len
, type
);
2786 match_records(struct ftrace_hash
*hash
, char *buff
,
2787 int len
, char *mod
, int not)
2789 unsigned search_len
= 0;
2790 struct ftrace_page
*pg
;
2791 struct dyn_ftrace
*rec
;
2792 int type
= MATCH_FULL
;
2793 char *search
= buff
;
2798 type
= filter_parse_regex(buff
, len
, &search
, ¬);
2799 search_len
= strlen(search
);
2802 mutex_lock(&ftrace_lock
);
2804 if (unlikely(ftrace_disabled
))
2807 do_for_each_ftrace_rec(pg
, rec
) {
2808 if (ftrace_match_record(rec
, mod
, search
, search_len
, type
)) {
2809 ret
= enter_record(hash
, rec
, not);
2816 } while_for_each_ftrace_rec();
2818 mutex_unlock(&ftrace_lock
);
2824 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
2826 return match_records(hash
, buff
, len
, NULL
, 0);
2830 ftrace_match_module_records(struct ftrace_hash
*hash
, char *buff
, char *mod
)
2834 /* blank or '*' mean the same */
2835 if (strcmp(buff
, "*") == 0)
2838 /* handle the case of 'dont filter this module' */
2839 if (strcmp(buff
, "!") == 0 || strcmp(buff
, "!*") == 0) {
2844 return match_records(hash
, buff
, strlen(buff
), mod
, not);
2848 * We register the module command as a template to show others how
2849 * to register the a command as well.
2853 ftrace_mod_callback(struct ftrace_hash
*hash
,
2854 char *func
, char *cmd
, char *param
, int enable
)
2860 * cmd == 'mod' because we only registered this func
2861 * for the 'mod' ftrace_func_command.
2862 * But if you register one func with multiple commands,
2863 * you can tell which command was used by the cmd
2867 /* we must have a module name */
2871 mod
= strsep(¶m
, ":");
2875 ret
= ftrace_match_module_records(hash
, func
, mod
);
2884 static struct ftrace_func_command ftrace_mod_cmd
= {
2886 .func
= ftrace_mod_callback
,
2889 static int __init
ftrace_mod_cmd_init(void)
2891 return register_ftrace_command(&ftrace_mod_cmd
);
2893 core_initcall(ftrace_mod_cmd_init
);
2895 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
2896 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
2898 struct ftrace_func_probe
*entry
;
2899 struct hlist_head
*hhd
;
2902 key
= hash_long(ip
, FTRACE_HASH_BITS
);
2904 hhd
= &ftrace_func_hash
[key
];
2906 if (hlist_empty(hhd
))
2910 * Disable preemption for these calls to prevent a RCU grace
2911 * period. This syncs the hash iteration and freeing of items
2912 * on the hash. rcu_read_lock is too dangerous here.
2914 preempt_disable_notrace();
2915 hlist_for_each_entry_rcu(entry
, hhd
, node
) {
2916 if (entry
->ip
== ip
)
2917 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
2919 preempt_enable_notrace();
2922 static struct ftrace_ops trace_probe_ops __read_mostly
=
2924 .func
= function_trace_probe_call
,
2927 static int ftrace_probe_registered
;
2929 static void __enable_ftrace_function_probe(void)
2934 if (ftrace_probe_registered
)
2937 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
2938 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
2942 /* Nothing registered? */
2943 if (i
== FTRACE_FUNC_HASHSIZE
)
2946 ret
= __register_ftrace_function(&trace_probe_ops
);
2948 ret
= ftrace_startup(&trace_probe_ops
, 0);
2950 ftrace_probe_registered
= 1;
2953 static void __disable_ftrace_function_probe(void)
2958 if (!ftrace_probe_registered
)
2961 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
2962 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
2967 /* no more funcs left */
2968 ret
= __unregister_ftrace_function(&trace_probe_ops
);
2970 ftrace_shutdown(&trace_probe_ops
, 0);
2972 ftrace_probe_registered
= 0;
2976 static void ftrace_free_entry_rcu(struct rcu_head
*rhp
)
2978 struct ftrace_func_probe
*entry
=
2979 container_of(rhp
, struct ftrace_func_probe
, rcu
);
2981 if (entry
->ops
->free
)
2982 entry
->ops
->free(&entry
->data
);
2988 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
2991 struct ftrace_func_probe
*entry
;
2992 struct ftrace_page
*pg
;
2993 struct dyn_ftrace
*rec
;
2999 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3000 len
= strlen(search
);
3002 /* we do not support '!' for function probes */
3006 mutex_lock(&ftrace_lock
);
3008 if (unlikely(ftrace_disabled
))
3011 do_for_each_ftrace_rec(pg
, rec
) {
3013 if (!ftrace_match_record(rec
, NULL
, search
, len
, type
))
3016 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3018 /* If we did not process any, then return error */
3029 * The caller might want to do something special
3030 * for each function we find. We call the callback
3031 * to give the caller an opportunity to do so.
3033 if (ops
->callback
) {
3034 if (ops
->callback(rec
->ip
, &entry
->data
) < 0) {
3035 /* caller does not like this func */
3042 entry
->ip
= rec
->ip
;
3044 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3045 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3047 } while_for_each_ftrace_rec();
3048 __enable_ftrace_function_probe();
3051 mutex_unlock(&ftrace_lock
);
3057 PROBE_TEST_FUNC
= 1,
3062 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3063 void *data
, int flags
)
3065 struct ftrace_func_probe
*entry
;
3066 struct hlist_node
*tmp
;
3067 char str
[KSYM_SYMBOL_LEN
];
3068 int type
= MATCH_FULL
;
3072 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3077 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3078 len
= strlen(search
);
3080 /* we do not support '!' for function probes */
3085 mutex_lock(&ftrace_lock
);
3086 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3087 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3089 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3091 /* break up if statements for readability */
3092 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3095 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3098 /* do this last, since it is the most expensive */
3100 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3102 if (!ftrace_match(str
, glob
, len
, type
))
3106 hlist_del_rcu(&entry
->node
);
3107 call_rcu_sched(&entry
->rcu
, ftrace_free_entry_rcu
);
3110 __disable_ftrace_function_probe();
3111 mutex_unlock(&ftrace_lock
);
3115 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3118 __unregister_ftrace_function_probe(glob
, ops
, data
,
3119 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3123 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3125 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3128 void unregister_ftrace_function_probe_all(char *glob
)
3130 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3133 static LIST_HEAD(ftrace_commands
);
3134 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3136 int register_ftrace_command(struct ftrace_func_command
*cmd
)
3138 struct ftrace_func_command
*p
;
3141 mutex_lock(&ftrace_cmd_mutex
);
3142 list_for_each_entry(p
, &ftrace_commands
, list
) {
3143 if (strcmp(cmd
->name
, p
->name
) == 0) {
3148 list_add(&cmd
->list
, &ftrace_commands
);
3150 mutex_unlock(&ftrace_cmd_mutex
);
3155 int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
3157 struct ftrace_func_command
*p
, *n
;
3160 mutex_lock(&ftrace_cmd_mutex
);
3161 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
3162 if (strcmp(cmd
->name
, p
->name
) == 0) {
3164 list_del_init(&p
->list
);
3169 mutex_unlock(&ftrace_cmd_mutex
);
3174 static int ftrace_process_regex(struct ftrace_hash
*hash
,
3175 char *buff
, int len
, int enable
)
3177 char *func
, *command
, *next
= buff
;
3178 struct ftrace_func_command
*p
;
3181 func
= strsep(&next
, ":");
3184 ret
= ftrace_match_records(hash
, func
, len
);
3194 command
= strsep(&next
, ":");
3196 mutex_lock(&ftrace_cmd_mutex
);
3197 list_for_each_entry(p
, &ftrace_commands
, list
) {
3198 if (strcmp(p
->name
, command
) == 0) {
3199 ret
= p
->func(hash
, func
, command
, next
, enable
);
3204 mutex_unlock(&ftrace_cmd_mutex
);
3210 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
3211 size_t cnt
, loff_t
*ppos
, int enable
)
3213 struct ftrace_iterator
*iter
;
3214 struct trace_parser
*parser
;
3220 mutex_lock(&ftrace_regex_lock
);
3223 if (unlikely(ftrace_disabled
))
3226 if (file
->f_mode
& FMODE_READ
) {
3227 struct seq_file
*m
= file
->private_data
;
3230 iter
= file
->private_data
;
3232 parser
= &iter
->parser
;
3233 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
3235 if (read
>= 0 && trace_parser_loaded(parser
) &&
3236 !trace_parser_cont(parser
)) {
3237 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
3238 parser
->idx
, enable
);
3239 trace_parser_clear(parser
);
3246 mutex_unlock(&ftrace_regex_lock
);
3252 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
3253 size_t cnt
, loff_t
*ppos
)
3255 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
3259 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
3260 size_t cnt
, loff_t
*ppos
)
3262 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
3266 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
3268 struct ftrace_func_entry
*entry
;
3270 if (!ftrace_location(ip
))
3274 entry
= ftrace_lookup_ip(hash
, ip
);
3277 free_hash_entry(hash
, entry
);
3281 return add_hash_entry(hash
, ip
);
3285 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3286 unsigned long ip
, int remove
, int reset
, int enable
)
3288 struct ftrace_hash
**orig_hash
;
3289 struct ftrace_hash
*hash
;
3292 /* All global ops uses the global ops filters */
3293 if (ops
->flags
& FTRACE_OPS_FL_GLOBAL
)
3296 if (unlikely(ftrace_disabled
))
3300 orig_hash
= &ops
->filter_hash
;
3302 orig_hash
= &ops
->notrace_hash
;
3304 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3308 mutex_lock(&ftrace_regex_lock
);
3310 ftrace_filter_reset(hash
);
3311 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
3313 goto out_regex_unlock
;
3316 ret
= ftrace_match_addr(hash
, ip
, remove
);
3318 goto out_regex_unlock
;
3321 mutex_lock(&ftrace_lock
);
3322 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3323 if (!ret
&& ops
->flags
& FTRACE_OPS_FL_ENABLED
3325 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3327 mutex_unlock(&ftrace_lock
);
3330 mutex_unlock(&ftrace_regex_lock
);
3332 free_ftrace_hash(hash
);
3337 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
3338 int reset
, int enable
)
3340 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
3344 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3345 * @ops - the ops to set the filter with
3346 * @ip - the address to add to or remove from the filter.
3347 * @remove - non zero to remove the ip from the filter
3348 * @reset - non zero to reset all filters before applying this filter.
3350 * Filters denote which functions should be enabled when tracing is enabled
3351 * If @ip is NULL, it failes to update filter.
3353 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
3354 int remove
, int reset
)
3356 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
3358 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
3361 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3362 int reset
, int enable
)
3364 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
3368 * ftrace_set_filter - set a function to filter on in ftrace
3369 * @ops - the ops to set the filter with
3370 * @buf - the string that holds the function filter text.
3371 * @len - the length of the string.
3372 * @reset - non zero to reset all filters before applying this filter.
3374 * Filters denote which functions should be enabled when tracing is enabled.
3375 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3377 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
3380 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
3382 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
3385 * ftrace_set_notrace - set a function to not trace in ftrace
3386 * @ops - the ops to set the notrace filter with
3387 * @buf - the string that holds the function notrace text.
3388 * @len - the length of the string.
3389 * @reset - non zero to reset all filters before applying this filter.
3391 * Notrace Filters denote which functions should not be enabled when tracing
3392 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3395 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
3398 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
3400 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
3402 * ftrace_set_filter - set a function to filter on in ftrace
3403 * @ops - the ops to set the filter with
3404 * @buf - the string that holds the function filter text.
3405 * @len - the length of the string.
3406 * @reset - non zero to reset all filters before applying this filter.
3408 * Filters denote which functions should be enabled when tracing is enabled.
3409 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3411 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
3413 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
3415 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
3418 * ftrace_set_notrace - set a function to not trace in ftrace
3419 * @ops - the ops to set the notrace filter with
3420 * @buf - the string that holds the function notrace text.
3421 * @len - the length of the string.
3422 * @reset - non zero to reset all filters before applying this filter.
3424 * Notrace Filters denote which functions should not be enabled when tracing
3425 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3428 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
3430 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
3432 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
3435 * command line interface to allow users to set filters on boot up.
3437 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3438 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3439 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3441 static int __init
set_ftrace_notrace(char *str
)
3443 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
3446 __setup("ftrace_notrace=", set_ftrace_notrace
);
3448 static int __init
set_ftrace_filter(char *str
)
3450 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
3453 __setup("ftrace_filter=", set_ftrace_filter
);
3455 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3456 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3457 static int ftrace_set_func(unsigned long *array
, int *idx
, char *buffer
);
3459 static int __init
set_graph_function(char *str
)
3461 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
3464 __setup("ftrace_graph_filter=", set_graph_function
);
3466 static void __init
set_ftrace_early_graph(char *buf
)
3472 func
= strsep(&buf
, ",");
3473 /* we allow only one expression at a time */
3474 ret
= ftrace_set_func(ftrace_graph_funcs
, &ftrace_graph_count
,
3477 printk(KERN_DEBUG
"ftrace: function %s not "
3478 "traceable\n", func
);
3481 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3484 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
3489 func
= strsep(&buf
, ",");
3490 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
3494 static void __init
set_ftrace_early_filters(void)
3496 if (ftrace_filter_buf
[0])
3497 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
3498 if (ftrace_notrace_buf
[0])
3499 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
3500 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3501 if (ftrace_graph_buf
[0])
3502 set_ftrace_early_graph(ftrace_graph_buf
);
3503 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3506 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
3508 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
3509 struct ftrace_iterator
*iter
;
3510 struct ftrace_hash
**orig_hash
;
3511 struct trace_parser
*parser
;
3515 mutex_lock(&ftrace_regex_lock
);
3516 if (file
->f_mode
& FMODE_READ
) {
3519 seq_release(inode
, file
);
3521 iter
= file
->private_data
;
3523 parser
= &iter
->parser
;
3524 if (trace_parser_loaded(parser
)) {
3525 parser
->buffer
[parser
->idx
] = 0;
3526 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
3529 trace_parser_put(parser
);
3531 if (file
->f_mode
& FMODE_WRITE
) {
3532 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
3535 orig_hash
= &iter
->ops
->filter_hash
;
3537 orig_hash
= &iter
->ops
->notrace_hash
;
3539 mutex_lock(&ftrace_lock
);
3540 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
3541 orig_hash
, iter
->hash
);
3542 if (!ret
&& (iter
->ops
->flags
& FTRACE_OPS_FL_ENABLED
)
3544 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3546 mutex_unlock(&ftrace_lock
);
3548 free_ftrace_hash(iter
->hash
);
3551 mutex_unlock(&ftrace_regex_lock
);
3555 static const struct file_operations ftrace_avail_fops
= {
3556 .open
= ftrace_avail_open
,
3558 .llseek
= seq_lseek
,
3559 .release
= seq_release_private
,
3562 static const struct file_operations ftrace_enabled_fops
= {
3563 .open
= ftrace_enabled_open
,
3565 .llseek
= seq_lseek
,
3566 .release
= seq_release_private
,
3569 static const struct file_operations ftrace_filter_fops
= {
3570 .open
= ftrace_filter_open
,
3572 .write
= ftrace_filter_write
,
3573 .llseek
= ftrace_filter_lseek
,
3574 .release
= ftrace_regex_release
,
3577 static const struct file_operations ftrace_notrace_fops
= {
3578 .open
= ftrace_notrace_open
,
3580 .write
= ftrace_notrace_write
,
3581 .llseek
= ftrace_filter_lseek
,
3582 .release
= ftrace_regex_release
,
3585 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3587 static DEFINE_MUTEX(graph_lock
);
3589 int ftrace_graph_count
;
3590 int ftrace_graph_filter_enabled
;
3591 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
3594 __g_next(struct seq_file
*m
, loff_t
*pos
)
3596 if (*pos
>= ftrace_graph_count
)
3598 return &ftrace_graph_funcs
[*pos
];
3602 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3605 return __g_next(m
, pos
);
3608 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
3610 mutex_lock(&graph_lock
);
3612 /* Nothing, tell g_show to print all functions are enabled */
3613 if (!ftrace_graph_filter_enabled
&& !*pos
)
3616 return __g_next(m
, pos
);
3619 static void g_stop(struct seq_file
*m
, void *p
)
3621 mutex_unlock(&graph_lock
);
3624 static int g_show(struct seq_file
*m
, void *v
)
3626 unsigned long *ptr
= v
;
3631 if (ptr
== (unsigned long *)1) {
3632 seq_printf(m
, "#### all functions enabled ####\n");
3636 seq_printf(m
, "%ps\n", (void *)*ptr
);
3641 static const struct seq_operations ftrace_graph_seq_ops
= {
3649 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
3653 if (unlikely(ftrace_disabled
))
3656 mutex_lock(&graph_lock
);
3657 if ((file
->f_mode
& FMODE_WRITE
) &&
3658 (file
->f_flags
& O_TRUNC
)) {
3659 ftrace_graph_filter_enabled
= 0;
3660 ftrace_graph_count
= 0;
3661 memset(ftrace_graph_funcs
, 0, sizeof(ftrace_graph_funcs
));
3663 mutex_unlock(&graph_lock
);
3665 if (file
->f_mode
& FMODE_READ
)
3666 ret
= seq_open(file
, &ftrace_graph_seq_ops
);
3672 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
3674 if (file
->f_mode
& FMODE_READ
)
3675 seq_release(inode
, file
);
3680 ftrace_set_func(unsigned long *array
, int *idx
, char *buffer
)
3682 struct dyn_ftrace
*rec
;
3683 struct ftrace_page
*pg
;
3692 type
= filter_parse_regex(buffer
, strlen(buffer
), &search
, ¬);
3693 if (!not && *idx
>= FTRACE_GRAPH_MAX_FUNCS
)
3696 search_len
= strlen(search
);
3698 mutex_lock(&ftrace_lock
);
3700 if (unlikely(ftrace_disabled
)) {
3701 mutex_unlock(&ftrace_lock
);
3705 do_for_each_ftrace_rec(pg
, rec
) {
3707 if (ftrace_match_record(rec
, NULL
, search
, search_len
, type
)) {
3708 /* if it is in the array */
3710 for (i
= 0; i
< *idx
; i
++) {
3711 if (array
[i
] == rec
->ip
) {
3720 array
[(*idx
)++] = rec
->ip
;
3721 if (*idx
>= FTRACE_GRAPH_MAX_FUNCS
)
3726 array
[i
] = array
[--(*idx
)];
3732 } while_for_each_ftrace_rec();
3734 mutex_unlock(&ftrace_lock
);
3739 ftrace_graph_filter_enabled
= 1;
3744 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
3745 size_t cnt
, loff_t
*ppos
)
3747 struct trace_parser parser
;
3753 mutex_lock(&graph_lock
);
3755 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
)) {
3760 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
3762 if (read
>= 0 && trace_parser_loaded((&parser
))) {
3763 parser
.buffer
[parser
.idx
] = 0;
3765 /* we allow only one expression at a time */
3766 ret
= ftrace_set_func(ftrace_graph_funcs
, &ftrace_graph_count
,
3775 trace_parser_put(&parser
);
3777 mutex_unlock(&graph_lock
);
3782 static const struct file_operations ftrace_graph_fops
= {
3783 .open
= ftrace_graph_open
,
3785 .write
= ftrace_graph_write
,
3786 .llseek
= ftrace_filter_lseek
,
3787 .release
= ftrace_graph_release
,
3789 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3791 static __init
int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
)
3794 trace_create_file("available_filter_functions", 0444,
3795 d_tracer
, NULL
, &ftrace_avail_fops
);
3797 trace_create_file("enabled_functions", 0444,
3798 d_tracer
, NULL
, &ftrace_enabled_fops
);
3800 trace_create_file("set_ftrace_filter", 0644, d_tracer
,
3801 NULL
, &ftrace_filter_fops
);
3803 trace_create_file("set_ftrace_notrace", 0644, d_tracer
,
3804 NULL
, &ftrace_notrace_fops
);
3806 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3807 trace_create_file("set_graph_function", 0444, d_tracer
,
3809 &ftrace_graph_fops
);
3810 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3815 static int ftrace_cmp_ips(const void *a
, const void *b
)
3817 const unsigned long *ipa
= a
;
3818 const unsigned long *ipb
= b
;
3827 static void ftrace_swap_ips(void *a
, void *b
, int size
)
3829 unsigned long *ipa
= a
;
3830 unsigned long *ipb
= b
;
3838 static int ftrace_process_locs(struct module
*mod
,
3839 unsigned long *start
,
3842 struct ftrace_page
*start_pg
;
3843 struct ftrace_page
*pg
;
3844 struct dyn_ftrace
*rec
;
3845 unsigned long count
;
3848 unsigned long flags
= 0; /* Shut up gcc */
3851 count
= end
- start
;
3856 sort(start
, count
, sizeof(*start
),
3857 ftrace_cmp_ips
, ftrace_swap_ips
);
3859 start_pg
= ftrace_allocate_pages(count
);
3863 mutex_lock(&ftrace_lock
);
3866 * Core and each module needs their own pages, as
3867 * modules will free them when they are removed.
3868 * Force a new page to be allocated for modules.
3871 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
3872 /* First initialization */
3873 ftrace_pages
= ftrace_pages_start
= start_pg
;
3878 if (WARN_ON(ftrace_pages
->next
)) {
3879 /* Hmm, we have free pages? */
3880 while (ftrace_pages
->next
)
3881 ftrace_pages
= ftrace_pages
->next
;
3884 ftrace_pages
->next
= start_pg
;
3890 addr
= ftrace_call_adjust(*p
++);
3892 * Some architecture linkers will pad between
3893 * the different mcount_loc sections of different
3894 * object files to satisfy alignments.
3895 * Skip any NULL pointers.
3900 if (pg
->index
== pg
->size
) {
3901 /* We should have allocated enough */
3902 if (WARN_ON(!pg
->next
))
3907 rec
= &pg
->records
[pg
->index
++];
3911 /* We should have used all pages */
3914 /* Assign the last page to ftrace_pages */
3917 /* These new locations need to be initialized */
3918 ftrace_new_pgs
= start_pg
;
3921 * We only need to disable interrupts on start up
3922 * because we are modifying code that an interrupt
3923 * may execute, and the modification is not atomic.
3924 * But for modules, nothing runs the code we modify
3925 * until we are finished with it, and there's no
3926 * reason to cause large interrupt latencies while we do it.
3929 local_irq_save(flags
);
3930 ftrace_update_code(mod
);
3932 local_irq_restore(flags
);
3935 mutex_unlock(&ftrace_lock
);
3940 #ifdef CONFIG_MODULES
3942 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
3944 void ftrace_release_mod(struct module
*mod
)
3946 struct dyn_ftrace
*rec
;
3947 struct ftrace_page
**last_pg
;
3948 struct ftrace_page
*pg
;
3951 mutex_lock(&ftrace_lock
);
3953 if (ftrace_disabled
)
3957 * Each module has its own ftrace_pages, remove
3958 * them from the list.
3960 last_pg
= &ftrace_pages_start
;
3961 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
3962 rec
= &pg
->records
[0];
3963 if (within_module_core(rec
->ip
, mod
)) {
3965 * As core pages are first, the first
3966 * page should never be a module page.
3968 if (WARN_ON(pg
== ftrace_pages_start
))
3971 /* Check if we are deleting the last page */
3972 if (pg
== ftrace_pages
)
3973 ftrace_pages
= next_to_ftrace_page(last_pg
);
3975 *last_pg
= pg
->next
;
3976 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
3977 free_pages((unsigned long)pg
->records
, order
);
3980 last_pg
= &pg
->next
;
3983 mutex_unlock(&ftrace_lock
);
3986 static void ftrace_init_module(struct module
*mod
,
3987 unsigned long *start
, unsigned long *end
)
3989 if (ftrace_disabled
|| start
== end
)
3991 ftrace_process_locs(mod
, start
, end
);
3994 static int ftrace_module_notify_enter(struct notifier_block
*self
,
3995 unsigned long val
, void *data
)
3997 struct module
*mod
= data
;
3999 if (val
== MODULE_STATE_COMING
)
4000 ftrace_init_module(mod
, mod
->ftrace_callsites
,
4001 mod
->ftrace_callsites
+
4002 mod
->num_ftrace_callsites
);
4006 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4007 unsigned long val
, void *data
)
4009 struct module
*mod
= data
;
4011 if (val
== MODULE_STATE_GOING
)
4012 ftrace_release_mod(mod
);
4017 static int ftrace_module_notify_enter(struct notifier_block
*self
,
4018 unsigned long val
, void *data
)
4022 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4023 unsigned long val
, void *data
)
4027 #endif /* CONFIG_MODULES */
4029 struct notifier_block ftrace_module_enter_nb
= {
4030 .notifier_call
= ftrace_module_notify_enter
,
4031 .priority
= INT_MAX
, /* Run before anything that can use kprobes */
4034 struct notifier_block ftrace_module_exit_nb
= {
4035 .notifier_call
= ftrace_module_notify_exit
,
4036 .priority
= INT_MIN
, /* Run after anything that can remove kprobes */
4039 extern unsigned long __start_mcount_loc
[];
4040 extern unsigned long __stop_mcount_loc
[];
4042 void __init
ftrace_init(void)
4044 unsigned long count
, addr
, flags
;
4047 /* Keep the ftrace pointer to the stub */
4048 addr
= (unsigned long)ftrace_stub
;
4050 local_irq_save(flags
);
4051 ftrace_dyn_arch_init(&addr
);
4052 local_irq_restore(flags
);
4054 /* ftrace_dyn_arch_init places the return code in addr */
4058 count
= __stop_mcount_loc
- __start_mcount_loc
;
4060 ret
= ftrace_dyn_table_alloc(count
);
4064 last_ftrace_enabled
= ftrace_enabled
= 1;
4066 ret
= ftrace_process_locs(NULL
,
4070 ret
= register_module_notifier(&ftrace_module_enter_nb
);
4072 pr_warning("Failed to register trace ftrace module enter notifier\n");
4074 ret
= register_module_notifier(&ftrace_module_exit_nb
);
4076 pr_warning("Failed to register trace ftrace module exit notifier\n");
4078 set_ftrace_early_filters();
4082 ftrace_disabled
= 1;
4087 static struct ftrace_ops global_ops
= {
4088 .func
= ftrace_stub
,
4089 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
,
4092 static int __init
ftrace_nodyn_init(void)
4097 core_initcall(ftrace_nodyn_init
);
4099 static inline int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
) { return 0; }
4100 static inline void ftrace_startup_enable(int command
) { }
4101 /* Keep as macros so we do not need to define the commands */
4102 # define ftrace_startup(ops, command) \
4104 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4107 # define ftrace_shutdown(ops, command) do { } while (0)
4108 # define ftrace_startup_sysctl() do { } while (0)
4109 # define ftrace_shutdown_sysctl() do { } while (0)
4112 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
)
4117 #endif /* CONFIG_DYNAMIC_FTRACE */
4120 ftrace_ops_control_func(unsigned long ip
, unsigned long parent_ip
,
4121 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4123 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT
)))
4127 * Some of the ops may be dynamically allocated,
4128 * they must be freed after a synchronize_sched().
4130 preempt_disable_notrace();
4131 trace_recursion_set(TRACE_CONTROL_BIT
);
4132 do_for_each_ftrace_op(op
, ftrace_control_list
) {
4133 if (!(op
->flags
& FTRACE_OPS_FL_STUB
) &&
4134 !ftrace_function_local_disabled(op
) &&
4135 ftrace_ops_test(op
, ip
))
4136 op
->func(ip
, parent_ip
, op
, regs
);
4137 } while_for_each_ftrace_op(op
);
4138 trace_recursion_clear(TRACE_CONTROL_BIT
);
4139 preempt_enable_notrace();
4142 static struct ftrace_ops control_ops
= {
4143 .func
= ftrace_ops_control_func
,
4144 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
,
4148 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4149 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
4151 struct ftrace_ops
*op
;
4154 if (function_trace_stop
)
4157 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
4162 * Some of the ops may be dynamically allocated,
4163 * they must be freed after a synchronize_sched().
4165 preempt_disable_notrace();
4166 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4167 if (ftrace_ops_test(op
, ip
))
4168 op
->func(ip
, parent_ip
, op
, regs
);
4169 } while_for_each_ftrace_op(op
);
4170 preempt_enable_notrace();
4171 trace_clear_recursion(bit
);
4175 * Some archs only support passing ip and parent_ip. Even though
4176 * the list function ignores the op parameter, we do not want any
4177 * C side effects, where a function is called without the caller
4178 * sending a third parameter.
4179 * Archs are to support both the regs and ftrace_ops at the same time.
4180 * If they support ftrace_ops, it is assumed they support regs.
4181 * If call backs want to use regs, they must either check for regs
4182 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4183 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4184 * An architecture can pass partial regs with ftrace_ops and still
4185 * set the ARCH_SUPPORT_FTARCE_OPS.
4187 #if ARCH_SUPPORTS_FTRACE_OPS
4188 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4189 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4191 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
4194 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
4196 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
4200 static void clear_ftrace_swapper(void)
4202 struct task_struct
*p
;
4206 for_each_online_cpu(cpu
) {
4208 clear_tsk_trace_trace(p
);
4213 static void set_ftrace_swapper(void)
4215 struct task_struct
*p
;
4219 for_each_online_cpu(cpu
) {
4221 set_tsk_trace_trace(p
);
4226 static void clear_ftrace_pid(struct pid
*pid
)
4228 struct task_struct
*p
;
4231 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4232 clear_tsk_trace_trace(p
);
4233 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4239 static void set_ftrace_pid(struct pid
*pid
)
4241 struct task_struct
*p
;
4244 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4245 set_tsk_trace_trace(p
);
4246 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4250 static void clear_ftrace_pid_task(struct pid
*pid
)
4252 if (pid
== ftrace_swapper_pid
)
4253 clear_ftrace_swapper();
4255 clear_ftrace_pid(pid
);
4258 static void set_ftrace_pid_task(struct pid
*pid
)
4260 if (pid
== ftrace_swapper_pid
)
4261 set_ftrace_swapper();
4263 set_ftrace_pid(pid
);
4266 static int ftrace_pid_add(int p
)
4269 struct ftrace_pid
*fpid
;
4272 mutex_lock(&ftrace_lock
);
4275 pid
= ftrace_swapper_pid
;
4277 pid
= find_get_pid(p
);
4284 list_for_each_entry(fpid
, &ftrace_pids
, list
)
4285 if (fpid
->pid
== pid
)
4290 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
4294 list_add(&fpid
->list
, &ftrace_pids
);
4297 set_ftrace_pid_task(pid
);
4299 ftrace_update_pid_func();
4300 ftrace_startup_enable(0);
4302 mutex_unlock(&ftrace_lock
);
4306 if (pid
!= ftrace_swapper_pid
)
4310 mutex_unlock(&ftrace_lock
);
4314 static void ftrace_pid_reset(void)
4316 struct ftrace_pid
*fpid
, *safe
;
4318 mutex_lock(&ftrace_lock
);
4319 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
4320 struct pid
*pid
= fpid
->pid
;
4322 clear_ftrace_pid_task(pid
);
4324 list_del(&fpid
->list
);
4328 ftrace_update_pid_func();
4329 ftrace_startup_enable(0);
4331 mutex_unlock(&ftrace_lock
);
4334 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
4336 mutex_lock(&ftrace_lock
);
4338 if (list_empty(&ftrace_pids
) && (!*pos
))
4341 return seq_list_start(&ftrace_pids
, *pos
);
4344 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4349 return seq_list_next(v
, &ftrace_pids
, pos
);
4352 static void fpid_stop(struct seq_file
*m
, void *p
)
4354 mutex_unlock(&ftrace_lock
);
4357 static int fpid_show(struct seq_file
*m
, void *v
)
4359 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
4361 if (v
== (void *)1) {
4362 seq_printf(m
, "no pid\n");
4366 if (fpid
->pid
== ftrace_swapper_pid
)
4367 seq_printf(m
, "swapper tasks\n");
4369 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
4374 static const struct seq_operations ftrace_pid_sops
= {
4375 .start
= fpid_start
,
4382 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
4386 if ((file
->f_mode
& FMODE_WRITE
) &&
4387 (file
->f_flags
& O_TRUNC
))
4390 if (file
->f_mode
& FMODE_READ
)
4391 ret
= seq_open(file
, &ftrace_pid_sops
);
4397 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
4398 size_t cnt
, loff_t
*ppos
)
4404 if (cnt
>= sizeof(buf
))
4407 if (copy_from_user(&buf
, ubuf
, cnt
))
4413 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4414 * to clean the filter quietly.
4416 tmp
= strstrip(buf
);
4417 if (strlen(tmp
) == 0)
4420 ret
= kstrtol(tmp
, 10, &val
);
4424 ret
= ftrace_pid_add(val
);
4426 return ret
? ret
: cnt
;
4430 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
4432 if (file
->f_mode
& FMODE_READ
)
4433 seq_release(inode
, file
);
4438 static const struct file_operations ftrace_pid_fops
= {
4439 .open
= ftrace_pid_open
,
4440 .write
= ftrace_pid_write
,
4442 .llseek
= ftrace_filter_lseek
,
4443 .release
= ftrace_pid_release
,
4446 static __init
int ftrace_init_debugfs(void)
4448 struct dentry
*d_tracer
;
4450 d_tracer
= tracing_init_dentry();
4454 ftrace_init_dyn_debugfs(d_tracer
);
4456 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
4457 NULL
, &ftrace_pid_fops
);
4459 ftrace_profile_debugfs(d_tracer
);
4463 fs_initcall(ftrace_init_debugfs
);
4466 * ftrace_kill - kill ftrace
4468 * This function should be used by panic code. It stops ftrace
4469 * but in a not so nice way. If you need to simply kill ftrace
4470 * from a non-atomic section, use ftrace_kill.
4472 void ftrace_kill(void)
4474 ftrace_disabled
= 1;
4476 clear_ftrace_function();
4480 * Test if ftrace is dead or not.
4482 int ftrace_is_dead(void)
4484 return ftrace_disabled
;
4488 * register_ftrace_function - register a function for profiling
4489 * @ops - ops structure that holds the function for profiling.
4491 * Register a function to be called by all functions in the
4494 * Note: @ops->func and all the functions it calls must be labeled
4495 * with "notrace", otherwise it will go into a
4498 int register_ftrace_function(struct ftrace_ops
*ops
)
4502 mutex_lock(&ftrace_lock
);
4504 ret
= __register_ftrace_function(ops
);
4506 ret
= ftrace_startup(ops
, 0);
4508 mutex_unlock(&ftrace_lock
);
4512 EXPORT_SYMBOL_GPL(register_ftrace_function
);
4515 * unregister_ftrace_function - unregister a function for profiling.
4516 * @ops - ops structure that holds the function to unregister
4518 * Unregister a function that was added to be called by ftrace profiling.
4520 int unregister_ftrace_function(struct ftrace_ops
*ops
)
4524 mutex_lock(&ftrace_lock
);
4525 ret
= __unregister_ftrace_function(ops
);
4527 ftrace_shutdown(ops
, 0);
4528 mutex_unlock(&ftrace_lock
);
4532 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
4535 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
4536 void __user
*buffer
, size_t *lenp
,
4541 mutex_lock(&ftrace_lock
);
4543 if (unlikely(ftrace_disabled
))
4546 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
4548 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
4551 last_ftrace_enabled
= !!ftrace_enabled
;
4553 if (ftrace_enabled
) {
4555 ftrace_startup_sysctl();
4557 /* we are starting ftrace again */
4558 if (ftrace_ops_list
!= &ftrace_list_end
)
4559 update_ftrace_function();
4562 /* stopping ftrace calls (just send to ftrace_stub) */
4563 ftrace_trace_function
= ftrace_stub
;
4565 ftrace_shutdown_sysctl();
4569 mutex_unlock(&ftrace_lock
);
4573 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4575 static int ftrace_graph_active
;
4576 static struct notifier_block ftrace_suspend_notifier
;
4578 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
4583 /* The callbacks that hook a function */
4584 trace_func_graph_ret_t ftrace_graph_return
=
4585 (trace_func_graph_ret_t
)ftrace_stub
;
4586 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
4588 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
4589 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
4593 unsigned long flags
;
4594 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
4595 struct task_struct
*g
, *t
;
4597 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
4598 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
4599 * sizeof(struct ftrace_ret_stack
),
4601 if (!ret_stack_list
[i
]) {
4609 read_lock_irqsave(&tasklist_lock
, flags
);
4610 do_each_thread(g
, t
) {
4616 if (t
->ret_stack
== NULL
) {
4617 atomic_set(&t
->tracing_graph_pause
, 0);
4618 atomic_set(&t
->trace_overrun
, 0);
4619 t
->curr_ret_stack
= -1;
4620 /* Make sure the tasks see the -1 first: */
4622 t
->ret_stack
= ret_stack_list
[start
++];
4624 } while_each_thread(g
, t
);
4627 read_unlock_irqrestore(&tasklist_lock
, flags
);
4629 for (i
= start
; i
< end
; i
++)
4630 kfree(ret_stack_list
[i
]);
4635 ftrace_graph_probe_sched_switch(void *ignore
,
4636 struct task_struct
*prev
, struct task_struct
*next
)
4638 unsigned long long timestamp
;
4642 * Does the user want to count the time a function was asleep.
4643 * If so, do not update the time stamps.
4645 if (trace_flags
& TRACE_ITER_SLEEP_TIME
)
4648 timestamp
= trace_clock_local();
4650 prev
->ftrace_timestamp
= timestamp
;
4652 /* only process tasks that we timestamped */
4653 if (!next
->ftrace_timestamp
)
4657 * Update all the counters in next to make up for the
4658 * time next was sleeping.
4660 timestamp
-= next
->ftrace_timestamp
;
4662 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
4663 next
->ret_stack
[index
].calltime
+= timestamp
;
4666 /* Allocate a return stack for each task */
4667 static int start_graph_tracing(void)
4669 struct ftrace_ret_stack
**ret_stack_list
;
4672 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
4673 sizeof(struct ftrace_ret_stack
*),
4676 if (!ret_stack_list
)
4679 /* The cpu_boot init_task->ret_stack will never be freed */
4680 for_each_online_cpu(cpu
) {
4681 if (!idle_task(cpu
)->ret_stack
)
4682 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
4686 ret
= alloc_retstack_tasklist(ret_stack_list
);
4687 } while (ret
== -EAGAIN
);
4690 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
4692 pr_info("ftrace_graph: Couldn't activate tracepoint"
4693 " probe to kernel_sched_switch\n");
4696 kfree(ret_stack_list
);
4701 * Hibernation protection.
4702 * The state of the current task is too much unstable during
4703 * suspend/restore to disk. We want to protect against that.
4706 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
4710 case PM_HIBERNATION_PREPARE
:
4711 pause_graph_tracing();
4714 case PM_POST_HIBERNATION
:
4715 unpause_graph_tracing();
4721 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
4722 trace_func_graph_ent_t entryfunc
)
4726 mutex_lock(&ftrace_lock
);
4728 /* we currently allow only one tracer registered at a time */
4729 if (ftrace_graph_active
) {
4734 ftrace_suspend_notifier
.notifier_call
= ftrace_suspend_notifier_call
;
4735 register_pm_notifier(&ftrace_suspend_notifier
);
4737 ftrace_graph_active
++;
4738 ret
= start_graph_tracing();
4740 ftrace_graph_active
--;
4744 ftrace_graph_return
= retfunc
;
4745 ftrace_graph_entry
= entryfunc
;
4747 ret
= ftrace_startup(&global_ops
, FTRACE_START_FUNC_RET
);
4750 mutex_unlock(&ftrace_lock
);
4754 void unregister_ftrace_graph(void)
4756 mutex_lock(&ftrace_lock
);
4758 if (unlikely(!ftrace_graph_active
))
4761 ftrace_graph_active
--;
4762 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
4763 ftrace_graph_entry
= ftrace_graph_entry_stub
;
4764 ftrace_shutdown(&global_ops
, FTRACE_STOP_FUNC_RET
);
4765 unregister_pm_notifier(&ftrace_suspend_notifier
);
4766 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
4769 mutex_unlock(&ftrace_lock
);
4772 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
4775 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
4777 atomic_set(&t
->tracing_graph_pause
, 0);
4778 atomic_set(&t
->trace_overrun
, 0);
4779 t
->ftrace_timestamp
= 0;
4780 /* make curr_ret_stack visible before we add the ret_stack */
4782 t
->ret_stack
= ret_stack
;
4786 * Allocate a return stack for the idle task. May be the first
4787 * time through, or it may be done by CPU hotplug online.
4789 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
4791 t
->curr_ret_stack
= -1;
4793 * The idle task has no parent, it either has its own
4794 * stack or no stack at all.
4797 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
4799 if (ftrace_graph_active
) {
4800 struct ftrace_ret_stack
*ret_stack
;
4802 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
4804 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
4805 * sizeof(struct ftrace_ret_stack
),
4809 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
4811 graph_init_task(t
, ret_stack
);
4815 /* Allocate a return stack for newly created task */
4816 void ftrace_graph_init_task(struct task_struct
*t
)
4818 /* Make sure we do not use the parent ret_stack */
4819 t
->ret_stack
= NULL
;
4820 t
->curr_ret_stack
= -1;
4822 if (ftrace_graph_active
) {
4823 struct ftrace_ret_stack
*ret_stack
;
4825 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
4826 * sizeof(struct ftrace_ret_stack
),
4830 graph_init_task(t
, ret_stack
);
4834 void ftrace_graph_exit_task(struct task_struct
*t
)
4836 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
4838 t
->ret_stack
= NULL
;
4839 /* NULL must become visible to IRQs before we free it: */
4845 void ftrace_graph_stop(void)