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/tracefs.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 #ifdef CONFIG_DYNAMIC_FTRACE
66 #define INIT_OPS_HASH(opsname) \
67 .func_hash = &opsname.local_hash, \
68 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
69 #define ASSIGN_OPS_HASH(opsname, val) \
71 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
73 #define INIT_OPS_HASH(opsname)
74 #define ASSIGN_OPS_HASH(opsname, val)
77 static struct ftrace_ops ftrace_list_end __read_mostly
= {
79 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_STUB
,
80 INIT_OPS_HASH(ftrace_list_end
)
83 /* ftrace_enabled is a method to turn ftrace on or off */
84 int ftrace_enabled __read_mostly
;
85 static int last_ftrace_enabled
;
87 /* Current function tracing op */
88 struct ftrace_ops
*function_trace_op __read_mostly
= &ftrace_list_end
;
89 /* What to set function_trace_op to */
90 static struct ftrace_ops
*set_function_trace_op
;
92 /* List for set_ftrace_pid's pids. */
93 LIST_HEAD(ftrace_pids
);
95 struct list_head list
;
99 static bool ftrace_pids_enabled(void)
101 return !list_empty(&ftrace_pids
);
104 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
107 * ftrace_disabled is set when an anomaly is discovered.
108 * ftrace_disabled is much stronger than ftrace_enabled.
110 static int ftrace_disabled __read_mostly
;
112 static DEFINE_MUTEX(ftrace_lock
);
114 static struct ftrace_ops
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
115 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
116 static struct ftrace_ops global_ops
;
118 #if ARCH_SUPPORTS_FTRACE_OPS
119 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
120 struct ftrace_ops
*op
, struct pt_regs
*regs
);
122 /* See comment below, where ftrace_ops_list_func is defined */
123 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
124 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
128 * Traverse the ftrace_global_list, invoking all entries. The reason that we
129 * can use rcu_dereference_raw_notrace() is that elements removed from this list
130 * are simply leaked, so there is no need to interact with a grace-period
131 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
132 * concurrent insertions into the ftrace_global_list.
134 * Silly Alpha and silly pointer-speculation compiler optimizations!
136 #define do_for_each_ftrace_op(op, list) \
137 op = rcu_dereference_raw_notrace(list); \
141 * Optimized for just a single item in the list (as that is the normal case).
143 #define while_for_each_ftrace_op(op) \
144 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
145 unlikely((op) != &ftrace_list_end))
147 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
149 #ifdef CONFIG_DYNAMIC_FTRACE
150 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
151 mutex_init(&ops
->local_hash
.regex_lock
);
152 ops
->func_hash
= &ops
->local_hash
;
153 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
159 * ftrace_nr_registered_ops - return number of ops registered
161 * Returns the number of ftrace_ops registered and tracing functions
163 int ftrace_nr_registered_ops(void)
165 struct ftrace_ops
*ops
;
168 mutex_lock(&ftrace_lock
);
170 for (ops
= ftrace_ops_list
;
171 ops
!= &ftrace_list_end
; ops
= ops
->next
)
174 mutex_unlock(&ftrace_lock
);
179 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
180 struct ftrace_ops
*op
, struct pt_regs
*regs
)
182 if (!test_tsk_trace_trace(current
))
185 op
->saved_func(ip
, parent_ip
, op
, regs
);
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
;
199 static void per_cpu_ops_disable_all(struct ftrace_ops
*ops
)
203 for_each_possible_cpu(cpu
)
204 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
207 static int per_cpu_ops_alloc(struct ftrace_ops
*ops
)
209 int __percpu
*disabled
;
211 if (WARN_ON_ONCE(!(ops
->flags
& FTRACE_OPS_FL_PER_CPU
)))
214 disabled
= alloc_percpu(int);
218 ops
->disabled
= disabled
;
219 per_cpu_ops_disable_all(ops
);
223 static void ftrace_sync(struct work_struct
*work
)
226 * This function is just a stub to implement a hard force
227 * of synchronize_sched(). This requires synchronizing
228 * tasks even in userspace and idle.
230 * Yes, function tracing is rude.
234 static void ftrace_sync_ipi(void *data
)
236 /* Probably not needed, but do it anyway */
240 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
241 static void update_function_graph_func(void);
243 /* Both enabled by default (can be cleared by function_graph tracer flags */
244 static bool fgraph_sleep_time
= true;
245 static bool fgraph_graph_time
= true;
248 static inline void update_function_graph_func(void) { }
252 static ftrace_func_t
ftrace_ops_get_list_func(struct ftrace_ops
*ops
)
255 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
256 * then it needs to call the list anyway.
258 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
|
259 FTRACE_OPS_FL_RCU
) || FTRACE_FORCE_LIST_FUNC
)
260 return ftrace_ops_list_func
;
262 return ftrace_ops_get_func(ops
);
265 static void update_ftrace_function(void)
270 * Prepare the ftrace_ops that the arch callback will use.
271 * If there's only one ftrace_ops registered, the ftrace_ops_list
272 * will point to the ops we want.
274 set_function_trace_op
= ftrace_ops_list
;
276 /* If there's no ftrace_ops registered, just call the stub function */
277 if (ftrace_ops_list
== &ftrace_list_end
) {
281 * If we are at the end of the list and this ops is
282 * recursion safe and not dynamic and the arch supports passing ops,
283 * then have the mcount trampoline call the function directly.
285 } else if (ftrace_ops_list
->next
== &ftrace_list_end
) {
286 func
= ftrace_ops_get_list_func(ftrace_ops_list
);
289 /* Just use the default ftrace_ops */
290 set_function_trace_op
= &ftrace_list_end
;
291 func
= ftrace_ops_list_func
;
294 update_function_graph_func();
296 /* If there's no change, then do nothing more here */
297 if (ftrace_trace_function
== func
)
301 * If we are using the list function, it doesn't care
302 * about the function_trace_ops.
304 if (func
== ftrace_ops_list_func
) {
305 ftrace_trace_function
= func
;
307 * Don't even bother setting function_trace_ops,
308 * it would be racy to do so anyway.
313 #ifndef CONFIG_DYNAMIC_FTRACE
315 * For static tracing, we need to be a bit more careful.
316 * The function change takes affect immediately. Thus,
317 * we need to coorditate the setting of the function_trace_ops
318 * with the setting of the ftrace_trace_function.
320 * Set the function to the list ops, which will call the
321 * function we want, albeit indirectly, but it handles the
322 * ftrace_ops and doesn't depend on function_trace_op.
324 ftrace_trace_function
= ftrace_ops_list_func
;
326 * Make sure all CPUs see this. Yes this is slow, but static
327 * tracing is slow and nasty to have enabled.
329 schedule_on_each_cpu(ftrace_sync
);
330 /* Now all cpus are using the list ops. */
331 function_trace_op
= set_function_trace_op
;
332 /* Make sure the function_trace_op is visible on all CPUs */
334 /* Nasty way to force a rmb on all cpus */
335 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
336 /* OK, we are all set to update the ftrace_trace_function now! */
337 #endif /* !CONFIG_DYNAMIC_FTRACE */
339 ftrace_trace_function
= func
;
342 int using_ftrace_ops_list_func(void)
344 return ftrace_trace_function
== ftrace_ops_list_func
;
347 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
351 * We are entering ops into the list but another
352 * CPU might be walking that list. We need to make sure
353 * the ops->next pointer is valid before another CPU sees
354 * the ops pointer included into the list.
356 rcu_assign_pointer(*list
, ops
);
359 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
361 struct ftrace_ops
**p
;
364 * If we are removing the last function, then simply point
365 * to the ftrace_stub.
367 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
368 *list
= &ftrace_list_end
;
372 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
383 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
385 static int __register_ftrace_function(struct ftrace_ops
*ops
)
387 if (ops
->flags
& FTRACE_OPS_FL_DELETED
)
390 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
393 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
395 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
396 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
397 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
399 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
400 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
403 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
404 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
407 if (!core_kernel_data((unsigned long)ops
))
408 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
410 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
) {
411 if (per_cpu_ops_alloc(ops
))
415 add_ftrace_ops(&ftrace_ops_list
, ops
);
417 /* Always save the function, and reset at unregistering */
418 ops
->saved_func
= ops
->func
;
420 if (ops
->flags
& FTRACE_OPS_FL_PID
&& ftrace_pids_enabled())
421 ops
->func
= ftrace_pid_func
;
423 ftrace_update_trampoline(ops
);
426 update_ftrace_function();
431 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
435 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
438 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
444 update_ftrace_function();
446 ops
->func
= ops
->saved_func
;
451 static void ftrace_update_pid_func(void)
453 bool enabled
= ftrace_pids_enabled();
454 struct ftrace_ops
*op
;
456 /* Only do something if we are tracing something */
457 if (ftrace_trace_function
== ftrace_stub
)
460 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
461 if (op
->flags
& FTRACE_OPS_FL_PID
) {
462 op
->func
= enabled
? ftrace_pid_func
:
464 ftrace_update_trampoline(op
);
466 } while_for_each_ftrace_op(op
);
468 update_ftrace_function();
471 #ifdef CONFIG_FUNCTION_PROFILER
472 struct ftrace_profile
{
473 struct hlist_node node
;
475 unsigned long counter
;
476 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
477 unsigned long long time
;
478 unsigned long long time_squared
;
482 struct ftrace_profile_page
{
483 struct ftrace_profile_page
*next
;
485 struct ftrace_profile records
[];
488 struct ftrace_profile_stat
{
490 struct hlist_head
*hash
;
491 struct ftrace_profile_page
*pages
;
492 struct ftrace_profile_page
*start
;
493 struct tracer_stat stat
;
496 #define PROFILE_RECORDS_SIZE \
497 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
499 #define PROFILES_PER_PAGE \
500 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
502 static int ftrace_profile_enabled __read_mostly
;
504 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
505 static DEFINE_MUTEX(ftrace_profile_lock
);
507 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
509 #define FTRACE_PROFILE_HASH_BITS 10
510 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
513 function_stat_next(void *v
, int idx
)
515 struct ftrace_profile
*rec
= v
;
516 struct ftrace_profile_page
*pg
;
518 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
524 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
528 rec
= &pg
->records
[0];
536 static void *function_stat_start(struct tracer_stat
*trace
)
538 struct ftrace_profile_stat
*stat
=
539 container_of(trace
, struct ftrace_profile_stat
, stat
);
541 if (!stat
|| !stat
->start
)
544 return function_stat_next(&stat
->start
->records
[0], 0);
547 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
548 /* function graph compares on total time */
549 static int function_stat_cmp(void *p1
, void *p2
)
551 struct ftrace_profile
*a
= p1
;
552 struct ftrace_profile
*b
= p2
;
554 if (a
->time
< b
->time
)
556 if (a
->time
> b
->time
)
562 /* not function graph compares against hits */
563 static int function_stat_cmp(void *p1
, void *p2
)
565 struct ftrace_profile
*a
= p1
;
566 struct ftrace_profile
*b
= p2
;
568 if (a
->counter
< b
->counter
)
570 if (a
->counter
> b
->counter
)
577 static int function_stat_headers(struct seq_file
*m
)
579 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
580 seq_puts(m
, " Function "
583 "--- ---- --- ---\n");
585 seq_puts(m
, " Function Hit\n"
591 static int function_stat_show(struct seq_file
*m
, void *v
)
593 struct ftrace_profile
*rec
= v
;
594 char str
[KSYM_SYMBOL_LEN
];
596 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
597 static struct trace_seq s
;
598 unsigned long long avg
;
599 unsigned long long stddev
;
601 mutex_lock(&ftrace_profile_lock
);
603 /* we raced with function_profile_reset() */
604 if (unlikely(rec
->counter
== 0)) {
609 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
611 do_div(avg
, rec
->counter
);
612 if (tracing_thresh
&& (avg
< tracing_thresh
))
616 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
617 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
619 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
622 /* Sample standard deviation (s^2) */
623 if (rec
->counter
<= 1)
627 * Apply Welford's method:
628 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
630 stddev
= rec
->counter
* rec
->time_squared
-
631 rec
->time
* rec
->time
;
634 * Divide only 1000 for ns^2 -> us^2 conversion.
635 * trace_print_graph_duration will divide 1000 again.
637 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
641 trace_print_graph_duration(rec
->time
, &s
);
642 trace_seq_puts(&s
, " ");
643 trace_print_graph_duration(avg
, &s
);
644 trace_seq_puts(&s
, " ");
645 trace_print_graph_duration(stddev
, &s
);
646 trace_print_seq(m
, &s
);
650 mutex_unlock(&ftrace_profile_lock
);
655 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
657 struct ftrace_profile_page
*pg
;
659 pg
= stat
->pages
= stat
->start
;
662 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
667 memset(stat
->hash
, 0,
668 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
671 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
673 struct ftrace_profile_page
*pg
;
678 /* If we already allocated, do nothing */
682 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
686 #ifdef CONFIG_DYNAMIC_FTRACE
687 functions
= ftrace_update_tot_cnt
;
690 * We do not know the number of functions that exist because
691 * dynamic tracing is what counts them. With past experience
692 * we have around 20K functions. That should be more than enough.
693 * It is highly unlikely we will execute every function in
699 pg
= stat
->start
= stat
->pages
;
701 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
703 for (i
= 1; i
< pages
; i
++) {
704 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
715 unsigned long tmp
= (unsigned long)pg
;
727 static int ftrace_profile_init_cpu(int cpu
)
729 struct ftrace_profile_stat
*stat
;
732 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
735 /* If the profile is already created, simply reset it */
736 ftrace_profile_reset(stat
);
741 * We are profiling all functions, but usually only a few thousand
742 * functions are hit. We'll make a hash of 1024 items.
744 size
= FTRACE_PROFILE_HASH_SIZE
;
746 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
751 /* Preallocate the function profiling pages */
752 if (ftrace_profile_pages_init(stat
) < 0) {
761 static int ftrace_profile_init(void)
766 for_each_possible_cpu(cpu
) {
767 ret
= ftrace_profile_init_cpu(cpu
);
775 /* interrupts must be disabled */
776 static struct ftrace_profile
*
777 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
779 struct ftrace_profile
*rec
;
780 struct hlist_head
*hhd
;
783 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
784 hhd
= &stat
->hash
[key
];
786 if (hlist_empty(hhd
))
789 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
797 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
798 struct ftrace_profile
*rec
)
802 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
803 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
807 * The memory is already allocated, this simply finds a new record to use.
809 static struct ftrace_profile
*
810 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
812 struct ftrace_profile
*rec
= NULL
;
814 /* prevent recursion (from NMIs) */
815 if (atomic_inc_return(&stat
->disabled
) != 1)
819 * Try to find the function again since an NMI
820 * could have added it
822 rec
= ftrace_find_profiled_func(stat
, ip
);
826 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
827 if (!stat
->pages
->next
)
829 stat
->pages
= stat
->pages
->next
;
832 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
834 ftrace_add_profile(stat
, rec
);
837 atomic_dec(&stat
->disabled
);
843 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
844 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
846 struct ftrace_profile_stat
*stat
;
847 struct ftrace_profile
*rec
;
850 if (!ftrace_profile_enabled
)
853 local_irq_save(flags
);
855 stat
= this_cpu_ptr(&ftrace_profile_stats
);
856 if (!stat
->hash
|| !ftrace_profile_enabled
)
859 rec
= ftrace_find_profiled_func(stat
, ip
);
861 rec
= ftrace_profile_alloc(stat
, ip
);
868 local_irq_restore(flags
);
871 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
872 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
874 function_profile_call(trace
->func
, 0, NULL
, NULL
);
878 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
880 struct ftrace_profile_stat
*stat
;
881 unsigned long long calltime
;
882 struct ftrace_profile
*rec
;
885 local_irq_save(flags
);
886 stat
= this_cpu_ptr(&ftrace_profile_stats
);
887 if (!stat
->hash
|| !ftrace_profile_enabled
)
890 /* If the calltime was zero'd ignore it */
891 if (!trace
->calltime
)
894 calltime
= trace
->rettime
- trace
->calltime
;
896 if (!fgraph_graph_time
) {
899 index
= trace
->depth
;
901 /* Append this call time to the parent time to subtract */
903 current
->ret_stack
[index
- 1].subtime
+= calltime
;
905 if (current
->ret_stack
[index
].subtime
< calltime
)
906 calltime
-= current
->ret_stack
[index
].subtime
;
911 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
913 rec
->time
+= calltime
;
914 rec
->time_squared
+= calltime
* calltime
;
918 local_irq_restore(flags
);
921 static int register_ftrace_profiler(void)
923 return register_ftrace_graph(&profile_graph_return
,
924 &profile_graph_entry
);
927 static void unregister_ftrace_profiler(void)
929 unregister_ftrace_graph();
932 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
933 .func
= function_profile_call
,
934 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
935 INIT_OPS_HASH(ftrace_profile_ops
)
938 static int register_ftrace_profiler(void)
940 return register_ftrace_function(&ftrace_profile_ops
);
943 static void unregister_ftrace_profiler(void)
945 unregister_ftrace_function(&ftrace_profile_ops
);
947 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
950 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
951 size_t cnt
, loff_t
*ppos
)
956 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
962 mutex_lock(&ftrace_profile_lock
);
963 if (ftrace_profile_enabled
^ val
) {
965 ret
= ftrace_profile_init();
971 ret
= register_ftrace_profiler();
976 ftrace_profile_enabled
= 1;
978 ftrace_profile_enabled
= 0;
980 * unregister_ftrace_profiler calls stop_machine
981 * so this acts like an synchronize_sched.
983 unregister_ftrace_profiler();
987 mutex_unlock(&ftrace_profile_lock
);
995 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
996 size_t cnt
, loff_t
*ppos
)
998 char buf
[64]; /* big enough to hold a number */
1001 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
1002 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
1005 static const struct file_operations ftrace_profile_fops
= {
1006 .open
= tracing_open_generic
,
1007 .read
= ftrace_profile_read
,
1008 .write
= ftrace_profile_write
,
1009 .llseek
= default_llseek
,
1012 /* used to initialize the real stat files */
1013 static struct tracer_stat function_stats __initdata
= {
1014 .name
= "functions",
1015 .stat_start
= function_stat_start
,
1016 .stat_next
= function_stat_next
,
1017 .stat_cmp
= function_stat_cmp
,
1018 .stat_headers
= function_stat_headers
,
1019 .stat_show
= function_stat_show
1022 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1024 struct ftrace_profile_stat
*stat
;
1025 struct dentry
*entry
;
1030 for_each_possible_cpu(cpu
) {
1031 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1033 /* allocate enough for function name + cpu number */
1034 name
= kmalloc(32, GFP_KERNEL
);
1037 * The files created are permanent, if something happens
1038 * we still do not free memory.
1041 "Could not allocate stat file for cpu %d\n",
1045 stat
->stat
= function_stats
;
1046 snprintf(name
, 32, "function%d", cpu
);
1047 stat
->stat
.name
= name
;
1048 ret
= register_stat_tracer(&stat
->stat
);
1051 "Could not register function stat for cpu %d\n",
1058 entry
= tracefs_create_file("function_profile_enabled", 0644,
1059 d_tracer
, NULL
, &ftrace_profile_fops
);
1061 pr_warning("Could not create tracefs "
1062 "'function_profile_enabled' entry\n");
1065 #else /* CONFIG_FUNCTION_PROFILER */
1066 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1069 #endif /* CONFIG_FUNCTION_PROFILER */
1071 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1073 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1074 static int ftrace_graph_active
;
1076 # define ftrace_graph_active 0
1079 #ifdef CONFIG_DYNAMIC_FTRACE
1081 static struct ftrace_ops
*removed_ops
;
1084 * Set when doing a global update, like enabling all recs or disabling them.
1085 * It is not set when just updating a single ftrace_ops.
1087 static bool update_all_ops
;
1089 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1090 # error Dynamic ftrace depends on MCOUNT_RECORD
1093 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1095 struct ftrace_func_probe
{
1096 struct hlist_node node
;
1097 struct ftrace_probe_ops
*ops
;
1098 unsigned long flags
;
1101 struct list_head free_list
;
1104 struct ftrace_func_entry
{
1105 struct hlist_node hlist
;
1109 struct ftrace_hash
{
1110 unsigned long size_bits
;
1111 struct hlist_head
*buckets
;
1112 unsigned long count
;
1113 struct rcu_head rcu
;
1117 * We make these constant because no one should touch them,
1118 * but they are used as the default "empty hash", to avoid allocating
1119 * it all the time. These are in a read only section such that if
1120 * anyone does try to modify it, it will cause an exception.
1122 static const struct hlist_head empty_buckets
[1];
1123 static const struct ftrace_hash empty_hash
= {
1124 .buckets
= (struct hlist_head
*)empty_buckets
,
1126 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1128 static struct ftrace_ops global_ops
= {
1129 .func
= ftrace_stub
,
1130 .local_hash
.notrace_hash
= EMPTY_HASH
,
1131 .local_hash
.filter_hash
= EMPTY_HASH
,
1132 INIT_OPS_HASH(global_ops
)
1133 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
1134 FTRACE_OPS_FL_INITIALIZED
|
1139 * This is used by __kernel_text_address() to return true if the
1140 * address is on a dynamically allocated trampoline that would
1141 * not return true for either core_kernel_text() or
1142 * is_module_text_address().
1144 bool is_ftrace_trampoline(unsigned long addr
)
1146 struct ftrace_ops
*op
;
1150 * Some of the ops may be dynamically allocated,
1151 * they are freed after a synchronize_sched().
1153 preempt_disable_notrace();
1155 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1157 * This is to check for dynamically allocated trampolines.
1158 * Trampolines that are in kernel text will have
1159 * core_kernel_text() return true.
1161 if (op
->trampoline
&& op
->trampoline_size
)
1162 if (addr
>= op
->trampoline
&&
1163 addr
< op
->trampoline
+ op
->trampoline_size
) {
1167 } while_for_each_ftrace_op(op
);
1170 preempt_enable_notrace();
1175 struct ftrace_page
{
1176 struct ftrace_page
*next
;
1177 struct dyn_ftrace
*records
;
1182 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1183 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1185 /* estimate from running different kernels */
1186 #define NR_TO_INIT 10000
1188 static struct ftrace_page
*ftrace_pages_start
;
1189 static struct ftrace_page
*ftrace_pages
;
1191 static bool __always_inline
ftrace_hash_empty(struct ftrace_hash
*hash
)
1193 return !hash
|| !hash
->count
;
1196 static struct ftrace_func_entry
*
1197 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1200 struct ftrace_func_entry
*entry
;
1201 struct hlist_head
*hhd
;
1203 if (ftrace_hash_empty(hash
))
1206 if (hash
->size_bits
> 0)
1207 key
= hash_long(ip
, hash
->size_bits
);
1211 hhd
= &hash
->buckets
[key
];
1213 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1214 if (entry
->ip
== ip
)
1220 static void __add_hash_entry(struct ftrace_hash
*hash
,
1221 struct ftrace_func_entry
*entry
)
1223 struct hlist_head
*hhd
;
1226 if (hash
->size_bits
)
1227 key
= hash_long(entry
->ip
, hash
->size_bits
);
1231 hhd
= &hash
->buckets
[key
];
1232 hlist_add_head(&entry
->hlist
, hhd
);
1236 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1238 struct ftrace_func_entry
*entry
;
1240 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1245 __add_hash_entry(hash
, entry
);
1251 free_hash_entry(struct ftrace_hash
*hash
,
1252 struct ftrace_func_entry
*entry
)
1254 hlist_del(&entry
->hlist
);
1260 remove_hash_entry(struct ftrace_hash
*hash
,
1261 struct ftrace_func_entry
*entry
)
1263 hlist_del(&entry
->hlist
);
1267 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1269 struct hlist_head
*hhd
;
1270 struct hlist_node
*tn
;
1271 struct ftrace_func_entry
*entry
;
1272 int size
= 1 << hash
->size_bits
;
1278 for (i
= 0; i
< size
; i
++) {
1279 hhd
= &hash
->buckets
[i
];
1280 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1281 free_hash_entry(hash
, entry
);
1283 FTRACE_WARN_ON(hash
->count
);
1286 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1288 if (!hash
|| hash
== EMPTY_HASH
)
1290 ftrace_hash_clear(hash
);
1291 kfree(hash
->buckets
);
1295 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1297 struct ftrace_hash
*hash
;
1299 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1300 free_ftrace_hash(hash
);
1303 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1305 if (!hash
|| hash
== EMPTY_HASH
)
1307 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1310 void ftrace_free_filter(struct ftrace_ops
*ops
)
1312 ftrace_ops_init(ops
);
1313 free_ftrace_hash(ops
->func_hash
->filter_hash
);
1314 free_ftrace_hash(ops
->func_hash
->notrace_hash
);
1317 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1319 struct ftrace_hash
*hash
;
1322 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1326 size
= 1 << size_bits
;
1327 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1329 if (!hash
->buckets
) {
1334 hash
->size_bits
= size_bits
;
1339 static struct ftrace_hash
*
1340 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1342 struct ftrace_func_entry
*entry
;
1343 struct ftrace_hash
*new_hash
;
1348 new_hash
= alloc_ftrace_hash(size_bits
);
1353 if (ftrace_hash_empty(hash
))
1356 size
= 1 << hash
->size_bits
;
1357 for (i
= 0; i
< size
; i
++) {
1358 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1359 ret
= add_hash_entry(new_hash
, entry
->ip
);
1365 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1370 free_ftrace_hash(new_hash
);
1375 ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1377 ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1379 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1380 struct ftrace_hash
*new_hash
);
1383 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1384 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1386 struct ftrace_func_entry
*entry
;
1387 struct hlist_node
*tn
;
1388 struct hlist_head
*hhd
;
1389 struct ftrace_hash
*new_hash
;
1390 int size
= src
->count
;
1395 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1396 if (ops
->flags
& FTRACE_OPS_FL_IPMODIFY
&& !enable
)
1400 * If the new source is empty, just free dst and assign it
1404 new_hash
= EMPTY_HASH
;
1409 * Make the hash size about 1/2 the # found
1411 for (size
/= 2; size
; size
>>= 1)
1414 /* Don't allocate too much */
1415 if (bits
> FTRACE_HASH_MAX_BITS
)
1416 bits
= FTRACE_HASH_MAX_BITS
;
1418 new_hash
= alloc_ftrace_hash(bits
);
1422 size
= 1 << src
->size_bits
;
1423 for (i
= 0; i
< size
; i
++) {
1424 hhd
= &src
->buckets
[i
];
1425 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1426 remove_hash_entry(src
, entry
);
1427 __add_hash_entry(new_hash
, entry
);
1432 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1434 /* IPMODIFY should be updated only when filter_hash updating */
1435 ret
= ftrace_hash_ipmodify_update(ops
, new_hash
);
1437 free_ftrace_hash(new_hash
);
1443 * Remove the current set, update the hash and add
1446 ftrace_hash_rec_disable_modify(ops
, enable
);
1448 rcu_assign_pointer(*dst
, new_hash
);
1450 ftrace_hash_rec_enable_modify(ops
, enable
);
1455 static bool hash_contains_ip(unsigned long ip
,
1456 struct ftrace_ops_hash
*hash
)
1459 * The function record is a match if it exists in the filter
1460 * hash and not in the notrace hash. Note, an emty hash is
1461 * considered a match for the filter hash, but an empty
1462 * notrace hash is considered not in the notrace hash.
1464 return (ftrace_hash_empty(hash
->filter_hash
) ||
1465 ftrace_lookup_ip(hash
->filter_hash
, ip
)) &&
1466 (ftrace_hash_empty(hash
->notrace_hash
) ||
1467 !ftrace_lookup_ip(hash
->notrace_hash
, ip
));
1471 * Test the hashes for this ops to see if we want to call
1472 * the ops->func or not.
1474 * It's a match if the ip is in the ops->filter_hash or
1475 * the filter_hash does not exist or is empty,
1477 * the ip is not in the ops->notrace_hash.
1479 * This needs to be called with preemption disabled as
1480 * the hashes are freed with call_rcu_sched().
1483 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1485 struct ftrace_ops_hash hash
;
1488 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1490 * There's a small race when adding ops that the ftrace handler
1491 * that wants regs, may be called without them. We can not
1492 * allow that handler to be called if regs is NULL.
1494 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1498 hash
.filter_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->filter_hash
);
1499 hash
.notrace_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->notrace_hash
);
1501 if (hash_contains_ip(ip
, &hash
))
1510 * This is a double for. Do not use 'break' to break out of the loop,
1511 * you must use a goto.
1513 #define do_for_each_ftrace_rec(pg, rec) \
1514 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1516 for (_____i = 0; _____i < pg->index; _____i++) { \
1517 rec = &pg->records[_____i];
1519 #define while_for_each_ftrace_rec() \
1524 static int ftrace_cmp_recs(const void *a
, const void *b
)
1526 const struct dyn_ftrace
*key
= a
;
1527 const struct dyn_ftrace
*rec
= b
;
1529 if (key
->flags
< rec
->ip
)
1531 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1537 * ftrace_location_range - return the first address of a traced location
1538 * if it touches the given ip range
1539 * @start: start of range to search.
1540 * @end: end of range to search (inclusive). @end points to the last byte
1543 * Returns rec->ip if the related ftrace location is a least partly within
1544 * the given address range. That is, the first address of the instruction
1545 * that is either a NOP or call to the function tracer. It checks the ftrace
1546 * internal tables to determine if the address belongs or not.
1548 unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1550 struct ftrace_page
*pg
;
1551 struct dyn_ftrace
*rec
;
1552 struct dyn_ftrace key
;
1555 key
.flags
= end
; /* overload flags, as it is unsigned long */
1557 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1558 if (end
< pg
->records
[0].ip
||
1559 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1561 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1562 sizeof(struct dyn_ftrace
),
1572 * ftrace_location - return true if the ip giving is a traced location
1573 * @ip: the instruction pointer to check
1575 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1576 * That is, the instruction that is either a NOP or call to
1577 * the function tracer. It checks the ftrace internal tables to
1578 * determine if the address belongs or not.
1580 unsigned long ftrace_location(unsigned long ip
)
1582 return ftrace_location_range(ip
, ip
);
1586 * ftrace_text_reserved - return true if range contains an ftrace location
1587 * @start: start of range to search
1588 * @end: end of range to search (inclusive). @end points to the last byte to check.
1590 * Returns 1 if @start and @end contains a ftrace location.
1591 * That is, the instruction that is either a NOP or call to
1592 * the function tracer. It checks the ftrace internal tables to
1593 * determine if the address belongs or not.
1595 int ftrace_text_reserved(const void *start
, const void *end
)
1599 ret
= ftrace_location_range((unsigned long)start
,
1600 (unsigned long)end
);
1605 /* Test if ops registered to this rec needs regs */
1606 static bool test_rec_ops_needs_regs(struct dyn_ftrace
*rec
)
1608 struct ftrace_ops
*ops
;
1609 bool keep_regs
= false;
1611 for (ops
= ftrace_ops_list
;
1612 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
1613 /* pass rec in as regs to have non-NULL val */
1614 if (ftrace_ops_test(ops
, rec
->ip
, rec
)) {
1615 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1625 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1629 struct ftrace_hash
*hash
;
1630 struct ftrace_hash
*other_hash
;
1631 struct ftrace_page
*pg
;
1632 struct dyn_ftrace
*rec
;
1636 /* Only update if the ops has been registered */
1637 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1641 * In the filter_hash case:
1642 * If the count is zero, we update all records.
1643 * Otherwise we just update the items in the hash.
1645 * In the notrace_hash case:
1646 * We enable the update in the hash.
1647 * As disabling notrace means enabling the tracing,
1648 * and enabling notrace means disabling, the inc variable
1652 hash
= ops
->func_hash
->filter_hash
;
1653 other_hash
= ops
->func_hash
->notrace_hash
;
1654 if (ftrace_hash_empty(hash
))
1658 hash
= ops
->func_hash
->notrace_hash
;
1659 other_hash
= ops
->func_hash
->filter_hash
;
1661 * If the notrace hash has no items,
1662 * then there's nothing to do.
1664 if (ftrace_hash_empty(hash
))
1668 do_for_each_ftrace_rec(pg
, rec
) {
1669 int in_other_hash
= 0;
1673 if (rec
->flags
& FTRACE_FL_DISABLED
)
1678 * Only the filter_hash affects all records.
1679 * Update if the record is not in the notrace hash.
1681 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1684 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1685 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1688 * If filter_hash is set, we want to match all functions
1689 * that are in the hash but not in the other hash.
1691 * If filter_hash is not set, then we are decrementing.
1692 * That means we match anything that is in the hash
1693 * and also in the other_hash. That is, we need to turn
1694 * off functions in the other hash because they are disabled
1697 if (filter_hash
&& in_hash
&& !in_other_hash
)
1699 else if (!filter_hash
&& in_hash
&&
1700 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1708 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == FTRACE_REF_MAX
))
1712 * If there's only a single callback registered to a
1713 * function, and the ops has a trampoline registered
1714 * for it, then we can call it directly.
1716 if (ftrace_rec_count(rec
) == 1 && ops
->trampoline
)
1717 rec
->flags
|= FTRACE_FL_TRAMP
;
1720 * If we are adding another function callback
1721 * to this function, and the previous had a
1722 * custom trampoline in use, then we need to go
1723 * back to the default trampoline.
1725 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1728 * If any ops wants regs saved for this function
1729 * then all ops will get saved regs.
1731 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1732 rec
->flags
|= FTRACE_FL_REGS
;
1734 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == 0))
1739 * If the rec had REGS enabled and the ops that is
1740 * being removed had REGS set, then see if there is
1741 * still any ops for this record that wants regs.
1742 * If not, we can stop recording them.
1744 if (ftrace_rec_count(rec
) > 0 &&
1745 rec
->flags
& FTRACE_FL_REGS
&&
1746 ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1747 if (!test_rec_ops_needs_regs(rec
))
1748 rec
->flags
&= ~FTRACE_FL_REGS
;
1752 * If the rec had TRAMP enabled, then it needs to
1753 * be cleared. As TRAMP can only be enabled iff
1754 * there is only a single ops attached to it.
1755 * In otherwords, always disable it on decrementing.
1756 * In the future, we may set it if rec count is
1757 * decremented to one, and the ops that is left
1760 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1763 * flags will be cleared in ftrace_check_record()
1764 * if rec count is zero.
1768 /* Shortcut, if we handled all records, we are done. */
1769 if (!all
&& count
== hash
->count
)
1771 } while_for_each_ftrace_rec();
1774 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1777 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1780 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1783 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1786 static void ftrace_hash_rec_update_modify(struct ftrace_ops
*ops
,
1787 int filter_hash
, int inc
)
1789 struct ftrace_ops
*op
;
1791 __ftrace_hash_rec_update(ops
, filter_hash
, inc
);
1793 if (ops
->func_hash
!= &global_ops
.local_hash
)
1797 * If the ops shares the global_ops hash, then we need to update
1798 * all ops that are enabled and use this hash.
1800 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1804 if (op
->func_hash
== &global_ops
.local_hash
)
1805 __ftrace_hash_rec_update(op
, filter_hash
, inc
);
1806 } while_for_each_ftrace_op(op
);
1809 static void ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
,
1812 ftrace_hash_rec_update_modify(ops
, filter_hash
, 0);
1815 static void ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
,
1818 ftrace_hash_rec_update_modify(ops
, filter_hash
, 1);
1822 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1823 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1824 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1825 * Note that old_hash and new_hash has below meanings
1826 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1827 * - If the hash is EMPTY_HASH, it hits nothing
1828 * - Anything else hits the recs which match the hash entries.
1830 static int __ftrace_hash_update_ipmodify(struct ftrace_ops
*ops
,
1831 struct ftrace_hash
*old_hash
,
1832 struct ftrace_hash
*new_hash
)
1834 struct ftrace_page
*pg
;
1835 struct dyn_ftrace
*rec
, *end
= NULL
;
1838 /* Only update if the ops has been registered */
1839 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1842 if (!(ops
->flags
& FTRACE_OPS_FL_IPMODIFY
))
1846 * Since the IPMODIFY is a very address sensitive action, we do not
1847 * allow ftrace_ops to set all functions to new hash.
1849 if (!new_hash
|| !old_hash
)
1852 /* Update rec->flags */
1853 do_for_each_ftrace_rec(pg
, rec
) {
1854 /* We need to update only differences of filter_hash */
1855 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1856 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1857 if (in_old
== in_new
)
1861 /* New entries must ensure no others are using it */
1862 if (rec
->flags
& FTRACE_FL_IPMODIFY
)
1864 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1865 } else /* Removed entry */
1866 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1867 } while_for_each_ftrace_rec();
1874 /* Roll back what we did above */
1875 do_for_each_ftrace_rec(pg
, rec
) {
1879 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1880 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1881 if (in_old
== in_new
)
1885 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1887 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1888 } while_for_each_ftrace_rec();
1894 static int ftrace_hash_ipmodify_enable(struct ftrace_ops
*ops
)
1896 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1898 if (ftrace_hash_empty(hash
))
1901 return __ftrace_hash_update_ipmodify(ops
, EMPTY_HASH
, hash
);
1904 /* Disabling always succeeds */
1905 static void ftrace_hash_ipmodify_disable(struct ftrace_ops
*ops
)
1907 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1909 if (ftrace_hash_empty(hash
))
1912 __ftrace_hash_update_ipmodify(ops
, hash
, EMPTY_HASH
);
1915 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1916 struct ftrace_hash
*new_hash
)
1918 struct ftrace_hash
*old_hash
= ops
->func_hash
->filter_hash
;
1920 if (ftrace_hash_empty(old_hash
))
1923 if (ftrace_hash_empty(new_hash
))
1926 return __ftrace_hash_update_ipmodify(ops
, old_hash
, new_hash
);
1929 static void print_ip_ins(const char *fmt
, const unsigned char *p
)
1933 printk(KERN_CONT
"%s", fmt
);
1935 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1936 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1939 static struct ftrace_ops
*
1940 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
);
1941 static struct ftrace_ops
*
1942 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
, struct ftrace_ops
*ops
);
1944 enum ftrace_bug_type ftrace_bug_type
;
1945 const void *ftrace_expected
;
1947 static void print_bug_type(void)
1949 switch (ftrace_bug_type
) {
1950 case FTRACE_BUG_UNKNOWN
:
1952 case FTRACE_BUG_INIT
:
1953 pr_info("Initializing ftrace call sites\n");
1955 case FTRACE_BUG_NOP
:
1956 pr_info("Setting ftrace call site to NOP\n");
1958 case FTRACE_BUG_CALL
:
1959 pr_info("Setting ftrace call site to call ftrace function\n");
1961 case FTRACE_BUG_UPDATE
:
1962 pr_info("Updating ftrace call site to call a different ftrace function\n");
1968 * ftrace_bug - report and shutdown function tracer
1969 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1970 * @rec: The record that failed
1972 * The arch code that enables or disables the function tracing
1973 * can call ftrace_bug() when it has detected a problem in
1974 * modifying the code. @failed should be one of either:
1975 * EFAULT - if the problem happens on reading the @ip address
1976 * EINVAL - if what is read at @ip is not what was expected
1977 * EPERM - if the problem happens on writting to the @ip address
1979 void ftrace_bug(int failed
, struct dyn_ftrace
*rec
)
1981 unsigned long ip
= rec
? rec
->ip
: 0;
1985 FTRACE_WARN_ON_ONCE(1);
1986 pr_info("ftrace faulted on modifying ");
1990 FTRACE_WARN_ON_ONCE(1);
1991 pr_info("ftrace failed to modify ");
1993 print_ip_ins(" actual: ", (unsigned char *)ip
);
1995 if (ftrace_expected
) {
1996 print_ip_ins(" expected: ", ftrace_expected
);
2001 FTRACE_WARN_ON_ONCE(1);
2002 pr_info("ftrace faulted on writing ");
2006 FTRACE_WARN_ON_ONCE(1);
2007 pr_info("ftrace faulted on unknown error ");
2012 struct ftrace_ops
*ops
= NULL
;
2014 pr_info("ftrace record flags: %lx\n", rec
->flags
);
2015 pr_cont(" (%ld)%s", ftrace_rec_count(rec
),
2016 rec
->flags
& FTRACE_FL_REGS
? " R" : " ");
2017 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2018 ops
= ftrace_find_tramp_ops_any(rec
);
2021 pr_cont("\ttramp: %pS (%pS)",
2022 (void *)ops
->trampoline
,
2024 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
2027 pr_cont("\ttramp: ERROR!");
2030 ip
= ftrace_get_addr_curr(rec
);
2031 pr_cont("\n expected tramp: %lx\n", ip
);
2035 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
2037 unsigned long flag
= 0UL;
2039 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2041 if (rec
->flags
& FTRACE_FL_DISABLED
)
2042 return FTRACE_UPDATE_IGNORE
;
2045 * If we are updating calls:
2047 * If the record has a ref count, then we need to enable it
2048 * because someone is using it.
2050 * Otherwise we make sure its disabled.
2052 * If we are disabling calls, then disable all records that
2055 if (enable
&& ftrace_rec_count(rec
))
2056 flag
= FTRACE_FL_ENABLED
;
2059 * If enabling and the REGS flag does not match the REGS_EN, or
2060 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2061 * this record. Set flags to fail the compare against ENABLED.
2064 if (!(rec
->flags
& FTRACE_FL_REGS
) !=
2065 !(rec
->flags
& FTRACE_FL_REGS_EN
))
2066 flag
|= FTRACE_FL_REGS
;
2068 if (!(rec
->flags
& FTRACE_FL_TRAMP
) !=
2069 !(rec
->flags
& FTRACE_FL_TRAMP_EN
))
2070 flag
|= FTRACE_FL_TRAMP
;
2073 /* If the state of this record hasn't changed, then do nothing */
2074 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
2075 return FTRACE_UPDATE_IGNORE
;
2078 /* Save off if rec is being enabled (for return value) */
2079 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
2082 rec
->flags
|= FTRACE_FL_ENABLED
;
2083 if (flag
& FTRACE_FL_REGS
) {
2084 if (rec
->flags
& FTRACE_FL_REGS
)
2085 rec
->flags
|= FTRACE_FL_REGS_EN
;
2087 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
2089 if (flag
& FTRACE_FL_TRAMP
) {
2090 if (rec
->flags
& FTRACE_FL_TRAMP
)
2091 rec
->flags
|= FTRACE_FL_TRAMP_EN
;
2093 rec
->flags
&= ~FTRACE_FL_TRAMP_EN
;
2098 * If this record is being updated from a nop, then
2099 * return UPDATE_MAKE_CALL.
2101 * return UPDATE_MODIFY_CALL to tell the caller to convert
2102 * from the save regs, to a non-save regs function or
2103 * vice versa, or from a trampoline call.
2105 if (flag
& FTRACE_FL_ENABLED
) {
2106 ftrace_bug_type
= FTRACE_BUG_CALL
;
2107 return FTRACE_UPDATE_MAKE_CALL
;
2110 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2111 return FTRACE_UPDATE_MODIFY_CALL
;
2115 /* If there's no more users, clear all flags */
2116 if (!ftrace_rec_count(rec
))
2120 * Just disable the record, but keep the ops TRAMP
2121 * and REGS states. The _EN flags must be disabled though.
2123 rec
->flags
&= ~(FTRACE_FL_ENABLED
| FTRACE_FL_TRAMP_EN
|
2127 ftrace_bug_type
= FTRACE_BUG_NOP
;
2128 return FTRACE_UPDATE_MAKE_NOP
;
2132 * ftrace_update_record, set a record that now is tracing or not
2133 * @rec: the record to update
2134 * @enable: set to 1 if the record is tracing, zero to force disable
2136 * The records that represent all functions that can be traced need
2137 * to be updated when tracing has been enabled.
2139 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
2141 return ftrace_check_record(rec
, enable
, 1);
2145 * ftrace_test_record, check if the record has been enabled or not
2146 * @rec: the record to test
2147 * @enable: set to 1 to check if enabled, 0 if it is disabled
2149 * The arch code may need to test if a record is already set to
2150 * tracing to determine how to modify the function code that it
2153 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
2155 return ftrace_check_record(rec
, enable
, 0);
2158 static struct ftrace_ops
*
2159 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
)
2161 struct ftrace_ops
*op
;
2162 unsigned long ip
= rec
->ip
;
2164 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2166 if (!op
->trampoline
)
2169 if (hash_contains_ip(ip
, op
->func_hash
))
2171 } while_for_each_ftrace_op(op
);
2176 static struct ftrace_ops
*
2177 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
,
2178 struct ftrace_ops
*op
)
2180 unsigned long ip
= rec
->ip
;
2182 while_for_each_ftrace_op(op
) {
2184 if (!op
->trampoline
)
2187 if (hash_contains_ip(ip
, op
->func_hash
))
2194 static struct ftrace_ops
*
2195 ftrace_find_tramp_ops_curr(struct dyn_ftrace
*rec
)
2197 struct ftrace_ops
*op
;
2198 unsigned long ip
= rec
->ip
;
2201 * Need to check removed ops first.
2202 * If they are being removed, and this rec has a tramp,
2203 * and this rec is in the ops list, then it would be the
2204 * one with the tramp.
2207 if (hash_contains_ip(ip
, &removed_ops
->old_hash
))
2212 * Need to find the current trampoline for a rec.
2213 * Now, a trampoline is only attached to a rec if there
2214 * was a single 'ops' attached to it. But this can be called
2215 * when we are adding another op to the rec or removing the
2216 * current one. Thus, if the op is being added, we can
2217 * ignore it because it hasn't attached itself to the rec
2220 * If an ops is being modified (hooking to different functions)
2221 * then we don't care about the new functions that are being
2222 * added, just the old ones (that are probably being removed).
2224 * If we are adding an ops to a function that already is using
2225 * a trampoline, it needs to be removed (trampolines are only
2226 * for single ops connected), then an ops that is not being
2227 * modified also needs to be checked.
2229 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2231 if (!op
->trampoline
)
2235 * If the ops is being added, it hasn't gotten to
2236 * the point to be removed from this tree yet.
2238 if (op
->flags
& FTRACE_OPS_FL_ADDING
)
2243 * If the ops is being modified and is in the old
2244 * hash, then it is probably being removed from this
2247 if ((op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2248 hash_contains_ip(ip
, &op
->old_hash
))
2251 * If the ops is not being added or modified, and it's
2252 * in its normal filter hash, then this must be the one
2255 if (!(op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2256 hash_contains_ip(ip
, op
->func_hash
))
2259 } while_for_each_ftrace_op(op
);
2264 static struct ftrace_ops
*
2265 ftrace_find_tramp_ops_new(struct dyn_ftrace
*rec
)
2267 struct ftrace_ops
*op
;
2268 unsigned long ip
= rec
->ip
;
2270 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2271 /* pass rec in as regs to have non-NULL val */
2272 if (hash_contains_ip(ip
, op
->func_hash
))
2274 } while_for_each_ftrace_op(op
);
2280 * ftrace_get_addr_new - Get the call address to set to
2281 * @rec: The ftrace record descriptor
2283 * If the record has the FTRACE_FL_REGS set, that means that it
2284 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2285 * is not not set, then it wants to convert to the normal callback.
2287 * Returns the address of the trampoline to set to
2289 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
)
2291 struct ftrace_ops
*ops
;
2293 /* Trampolines take precedence over regs */
2294 if (rec
->flags
& FTRACE_FL_TRAMP
) {
2295 ops
= ftrace_find_tramp_ops_new(rec
);
2296 if (FTRACE_WARN_ON(!ops
|| !ops
->trampoline
)) {
2297 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2298 (void *)rec
->ip
, (void *)rec
->ip
, rec
->flags
);
2299 /* Ftrace is shutting down, return anything */
2300 return (unsigned long)FTRACE_ADDR
;
2302 return ops
->trampoline
;
2305 if (rec
->flags
& FTRACE_FL_REGS
)
2306 return (unsigned long)FTRACE_REGS_ADDR
;
2308 return (unsigned long)FTRACE_ADDR
;
2312 * ftrace_get_addr_curr - Get the call address that is already there
2313 * @rec: The ftrace record descriptor
2315 * The FTRACE_FL_REGS_EN is set when the record already points to
2316 * a function that saves all the regs. Basically the '_EN' version
2317 * represents the current state of the function.
2319 * Returns the address of the trampoline that is currently being called
2321 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
)
2323 struct ftrace_ops
*ops
;
2325 /* Trampolines take precedence over regs */
2326 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2327 ops
= ftrace_find_tramp_ops_curr(rec
);
2328 if (FTRACE_WARN_ON(!ops
)) {
2329 pr_warning("Bad trampoline accounting at: %p (%pS)\n",
2330 (void *)rec
->ip
, (void *)rec
->ip
);
2331 /* Ftrace is shutting down, return anything */
2332 return (unsigned long)FTRACE_ADDR
;
2334 return ops
->trampoline
;
2337 if (rec
->flags
& FTRACE_FL_REGS_EN
)
2338 return (unsigned long)FTRACE_REGS_ADDR
;
2340 return (unsigned long)FTRACE_ADDR
;
2344 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
2346 unsigned long ftrace_old_addr
;
2347 unsigned long ftrace_addr
;
2350 ftrace_addr
= ftrace_get_addr_new(rec
);
2352 /* This needs to be done before we call ftrace_update_record */
2353 ftrace_old_addr
= ftrace_get_addr_curr(rec
);
2355 ret
= ftrace_update_record(rec
, enable
);
2357 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2360 case FTRACE_UPDATE_IGNORE
:
2363 case FTRACE_UPDATE_MAKE_CALL
:
2364 ftrace_bug_type
= FTRACE_BUG_CALL
;
2365 return ftrace_make_call(rec
, ftrace_addr
);
2367 case FTRACE_UPDATE_MAKE_NOP
:
2368 ftrace_bug_type
= FTRACE_BUG_NOP
;
2369 return ftrace_make_nop(NULL
, rec
, ftrace_old_addr
);
2371 case FTRACE_UPDATE_MODIFY_CALL
:
2372 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2373 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
2376 return -1; /* unknow ftrace bug */
2379 void __weak
ftrace_replace_code(int enable
)
2381 struct dyn_ftrace
*rec
;
2382 struct ftrace_page
*pg
;
2385 if (unlikely(ftrace_disabled
))
2388 do_for_each_ftrace_rec(pg
, rec
) {
2389 failed
= __ftrace_replace_code(rec
, enable
);
2391 ftrace_bug(failed
, rec
);
2392 /* Stop processing */
2395 } while_for_each_ftrace_rec();
2398 struct ftrace_rec_iter
{
2399 struct ftrace_page
*pg
;
2404 * ftrace_rec_iter_start, start up iterating over traced functions
2406 * Returns an iterator handle that is used to iterate over all
2407 * the records that represent address locations where functions
2410 * May return NULL if no records are available.
2412 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
2415 * We only use a single iterator.
2416 * Protected by the ftrace_lock mutex.
2418 static struct ftrace_rec_iter ftrace_rec_iter
;
2419 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
2421 iter
->pg
= ftrace_pages_start
;
2424 /* Could have empty pages */
2425 while (iter
->pg
&& !iter
->pg
->index
)
2426 iter
->pg
= iter
->pg
->next
;
2435 * ftrace_rec_iter_next, get the next record to process.
2436 * @iter: The handle to the iterator.
2438 * Returns the next iterator after the given iterator @iter.
2440 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
2444 if (iter
->index
>= iter
->pg
->index
) {
2445 iter
->pg
= iter
->pg
->next
;
2448 /* Could have empty pages */
2449 while (iter
->pg
&& !iter
->pg
->index
)
2450 iter
->pg
= iter
->pg
->next
;
2460 * ftrace_rec_iter_record, get the record at the iterator location
2461 * @iter: The current iterator location
2463 * Returns the record that the current @iter is at.
2465 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
2467 return &iter
->pg
->records
[iter
->index
];
2471 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
2475 if (unlikely(ftrace_disabled
))
2478 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
2480 ftrace_bug_type
= FTRACE_BUG_INIT
;
2481 ftrace_bug(ret
, rec
);
2488 * archs can override this function if they must do something
2489 * before the modifying code is performed.
2491 int __weak
ftrace_arch_code_modify_prepare(void)
2497 * archs can override this function if they must do something
2498 * after the modifying code is performed.
2500 int __weak
ftrace_arch_code_modify_post_process(void)
2505 void ftrace_modify_all_code(int command
)
2507 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
2511 * If the ftrace_caller calls a ftrace_ops func directly,
2512 * we need to make sure that it only traces functions it
2513 * expects to trace. When doing the switch of functions,
2514 * we need to update to the ftrace_ops_list_func first
2515 * before the transition between old and new calls are set,
2516 * as the ftrace_ops_list_func will check the ops hashes
2517 * to make sure the ops are having the right functions
2521 err
= ftrace_update_ftrace_func(ftrace_ops_list_func
);
2522 if (FTRACE_WARN_ON(err
))
2526 if (command
& FTRACE_UPDATE_CALLS
)
2527 ftrace_replace_code(1);
2528 else if (command
& FTRACE_DISABLE_CALLS
)
2529 ftrace_replace_code(0);
2531 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
) {
2532 function_trace_op
= set_function_trace_op
;
2534 /* If irqs are disabled, we are in stop machine */
2535 if (!irqs_disabled())
2536 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2537 err
= ftrace_update_ftrace_func(ftrace_trace_function
);
2538 if (FTRACE_WARN_ON(err
))
2542 if (command
& FTRACE_START_FUNC_RET
)
2543 err
= ftrace_enable_ftrace_graph_caller();
2544 else if (command
& FTRACE_STOP_FUNC_RET
)
2545 err
= ftrace_disable_ftrace_graph_caller();
2546 FTRACE_WARN_ON(err
);
2549 static int __ftrace_modify_code(void *data
)
2551 int *command
= data
;
2553 ftrace_modify_all_code(*command
);
2559 * ftrace_run_stop_machine, go back to the stop machine method
2560 * @command: The command to tell ftrace what to do
2562 * If an arch needs to fall back to the stop machine method, the
2563 * it can call this function.
2565 void ftrace_run_stop_machine(int command
)
2567 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2571 * arch_ftrace_update_code, modify the code to trace or not trace
2572 * @command: The command that needs to be done
2574 * Archs can override this function if it does not need to
2575 * run stop_machine() to modify code.
2577 void __weak
arch_ftrace_update_code(int command
)
2579 ftrace_run_stop_machine(command
);
2582 static void ftrace_run_update_code(int command
)
2586 ret
= ftrace_arch_code_modify_prepare();
2587 FTRACE_WARN_ON(ret
);
2592 * By default we use stop_machine() to modify the code.
2593 * But archs can do what ever they want as long as it
2594 * is safe. The stop_machine() is the safest, but also
2595 * produces the most overhead.
2597 arch_ftrace_update_code(command
);
2599 ret
= ftrace_arch_code_modify_post_process();
2600 FTRACE_WARN_ON(ret
);
2603 static void ftrace_run_modify_code(struct ftrace_ops
*ops
, int command
,
2604 struct ftrace_ops_hash
*old_hash
)
2606 ops
->flags
|= FTRACE_OPS_FL_MODIFYING
;
2607 ops
->old_hash
.filter_hash
= old_hash
->filter_hash
;
2608 ops
->old_hash
.notrace_hash
= old_hash
->notrace_hash
;
2609 ftrace_run_update_code(command
);
2610 ops
->old_hash
.filter_hash
= NULL
;
2611 ops
->old_hash
.notrace_hash
= NULL
;
2612 ops
->flags
&= ~FTRACE_OPS_FL_MODIFYING
;
2615 static ftrace_func_t saved_ftrace_func
;
2616 static int ftrace_start_up
;
2618 void __weak
arch_ftrace_trampoline_free(struct ftrace_ops
*ops
)
2622 static void per_cpu_ops_free(struct ftrace_ops
*ops
)
2624 free_percpu(ops
->disabled
);
2627 static void ftrace_startup_enable(int command
)
2629 if (saved_ftrace_func
!= ftrace_trace_function
) {
2630 saved_ftrace_func
= ftrace_trace_function
;
2631 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2634 if (!command
|| !ftrace_enabled
)
2637 ftrace_run_update_code(command
);
2640 static void ftrace_startup_all(int command
)
2642 update_all_ops
= true;
2643 ftrace_startup_enable(command
);
2644 update_all_ops
= false;
2647 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2651 if (unlikely(ftrace_disabled
))
2654 ret
= __register_ftrace_function(ops
);
2659 command
|= FTRACE_UPDATE_CALLS
;
2662 * Note that ftrace probes uses this to start up
2663 * and modify functions it will probe. But we still
2664 * set the ADDING flag for modification, as probes
2665 * do not have trampolines. If they add them in the
2666 * future, then the probes will need to distinguish
2667 * between adding and updating probes.
2669 ops
->flags
|= FTRACE_OPS_FL_ENABLED
| FTRACE_OPS_FL_ADDING
;
2671 ret
= ftrace_hash_ipmodify_enable(ops
);
2673 /* Rollback registration process */
2674 __unregister_ftrace_function(ops
);
2676 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2680 ftrace_hash_rec_enable(ops
, 1);
2682 ftrace_startup_enable(command
);
2684 ops
->flags
&= ~FTRACE_OPS_FL_ADDING
;
2689 static int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2693 if (unlikely(ftrace_disabled
))
2696 ret
= __unregister_ftrace_function(ops
);
2702 * Just warn in case of unbalance, no need to kill ftrace, it's not
2703 * critical but the ftrace_call callers may be never nopped again after
2704 * further ftrace uses.
2706 WARN_ON_ONCE(ftrace_start_up
< 0);
2708 /* Disabling ipmodify never fails */
2709 ftrace_hash_ipmodify_disable(ops
);
2710 ftrace_hash_rec_disable(ops
, 1);
2712 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2714 command
|= FTRACE_UPDATE_CALLS
;
2716 if (saved_ftrace_func
!= ftrace_trace_function
) {
2717 saved_ftrace_func
= ftrace_trace_function
;
2718 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2721 if (!command
|| !ftrace_enabled
) {
2723 * If these are per_cpu ops, they still need their
2724 * per_cpu field freed. Since, function tracing is
2725 * not currently active, we can just free them
2726 * without synchronizing all CPUs.
2728 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
)
2729 per_cpu_ops_free(ops
);
2734 * If the ops uses a trampoline, then it needs to be
2735 * tested first on update.
2737 ops
->flags
|= FTRACE_OPS_FL_REMOVING
;
2740 /* The trampoline logic checks the old hashes */
2741 ops
->old_hash
.filter_hash
= ops
->func_hash
->filter_hash
;
2742 ops
->old_hash
.notrace_hash
= ops
->func_hash
->notrace_hash
;
2744 ftrace_run_update_code(command
);
2747 * If there's no more ops registered with ftrace, run a
2748 * sanity check to make sure all rec flags are cleared.
2750 if (ftrace_ops_list
== &ftrace_list_end
) {
2751 struct ftrace_page
*pg
;
2752 struct dyn_ftrace
*rec
;
2754 do_for_each_ftrace_rec(pg
, rec
) {
2755 if (FTRACE_WARN_ON_ONCE(rec
->flags
))
2756 pr_warn(" %pS flags:%lx\n",
2757 (void *)rec
->ip
, rec
->flags
);
2758 } while_for_each_ftrace_rec();
2761 ops
->old_hash
.filter_hash
= NULL
;
2762 ops
->old_hash
.notrace_hash
= NULL
;
2765 ops
->flags
&= ~FTRACE_OPS_FL_REMOVING
;
2768 * Dynamic ops may be freed, we must make sure that all
2769 * callers are done before leaving this function.
2770 * The same goes for freeing the per_cpu data of the per_cpu
2773 * Again, normal synchronize_sched() is not good enough.
2774 * We need to do a hard force of sched synchronization.
2775 * This is because we use preempt_disable() to do RCU, but
2776 * the function tracers can be called where RCU is not watching
2777 * (like before user_exit()). We can not rely on the RCU
2778 * infrastructure to do the synchronization, thus we must do it
2781 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_PER_CPU
)) {
2782 schedule_on_each_cpu(ftrace_sync
);
2784 arch_ftrace_trampoline_free(ops
);
2786 if (ops
->flags
& FTRACE_OPS_FL_PER_CPU
)
2787 per_cpu_ops_free(ops
);
2793 static void ftrace_startup_sysctl(void)
2797 if (unlikely(ftrace_disabled
))
2800 /* Force update next time */
2801 saved_ftrace_func
= NULL
;
2802 /* ftrace_start_up is true if we want ftrace running */
2803 if (ftrace_start_up
) {
2804 command
= FTRACE_UPDATE_CALLS
;
2805 if (ftrace_graph_active
)
2806 command
|= FTRACE_START_FUNC_RET
;
2807 ftrace_startup_enable(command
);
2811 static void ftrace_shutdown_sysctl(void)
2815 if (unlikely(ftrace_disabled
))
2818 /* ftrace_start_up is true if ftrace is running */
2819 if (ftrace_start_up
) {
2820 command
= FTRACE_DISABLE_CALLS
;
2821 if (ftrace_graph_active
)
2822 command
|= FTRACE_STOP_FUNC_RET
;
2823 ftrace_run_update_code(command
);
2827 static cycle_t ftrace_update_time
;
2828 unsigned long ftrace_update_tot_cnt
;
2830 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2833 * Filter_hash being empty will default to trace module.
2834 * But notrace hash requires a test of individual module functions.
2836 return ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2837 ftrace_hash_empty(ops
->func_hash
->notrace_hash
);
2841 * Check if the current ops references the record.
2843 * If the ops traces all functions, then it was already accounted for.
2844 * If the ops does not trace the current record function, skip it.
2845 * If the ops ignores the function via notrace filter, skip it.
2848 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2850 /* If ops isn't enabled, ignore it */
2851 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2854 /* If ops traces all then it includes this function */
2855 if (ops_traces_mod(ops
))
2858 /* The function must be in the filter */
2859 if (!ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2860 !ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))
2863 /* If in notrace hash, we ignore it too */
2864 if (ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
))
2870 static int ftrace_update_code(struct module
*mod
, struct ftrace_page
*new_pgs
)
2872 struct ftrace_page
*pg
;
2873 struct dyn_ftrace
*p
;
2874 cycle_t start
, stop
;
2875 unsigned long update_cnt
= 0;
2876 unsigned long rec_flags
= 0;
2879 start
= ftrace_now(raw_smp_processor_id());
2882 * When a module is loaded, this function is called to convert
2883 * the calls to mcount in its text to nops, and also to create
2884 * an entry in the ftrace data. Now, if ftrace is activated
2885 * after this call, but before the module sets its text to
2886 * read-only, the modification of enabling ftrace can fail if
2887 * the read-only is done while ftrace is converting the calls.
2888 * To prevent this, the module's records are set as disabled
2889 * and will be enabled after the call to set the module's text
2893 rec_flags
|= FTRACE_FL_DISABLED
;
2895 for (pg
= new_pgs
; pg
; pg
= pg
->next
) {
2897 for (i
= 0; i
< pg
->index
; i
++) {
2899 /* If something went wrong, bail without enabling anything */
2900 if (unlikely(ftrace_disabled
))
2903 p
= &pg
->records
[i
];
2904 p
->flags
= rec_flags
;
2907 * Do the initial record conversion from mcount jump
2908 * to the NOP instructions.
2910 if (!ftrace_code_disable(mod
, p
))
2917 stop
= ftrace_now(raw_smp_processor_id());
2918 ftrace_update_time
= stop
- start
;
2919 ftrace_update_tot_cnt
+= update_cnt
;
2924 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2929 if (WARN_ON(!count
))
2932 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2935 * We want to fill as much as possible. No more than a page
2938 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2942 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2945 /* if we can't allocate this size, try something smaller */
2952 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2961 static struct ftrace_page
*
2962 ftrace_allocate_pages(unsigned long num_to_init
)
2964 struct ftrace_page
*start_pg
;
2965 struct ftrace_page
*pg
;
2972 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2977 * Try to allocate as much as possible in one continues
2978 * location that fills in all of the space. We want to
2979 * waste as little space as possible.
2982 cnt
= ftrace_allocate_records(pg
, num_to_init
);
2990 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3002 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
3003 free_pages((unsigned long)pg
->records
, order
);
3004 start_pg
= pg
->next
;
3008 pr_info("ftrace: FAILED to allocate memory for functions\n");
3012 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3014 struct ftrace_iterator
{
3017 struct ftrace_page
*pg
;
3018 struct dyn_ftrace
*func
;
3019 struct ftrace_func_probe
*probe
;
3020 struct trace_parser parser
;
3021 struct ftrace_hash
*hash
;
3022 struct ftrace_ops
*ops
;
3029 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
3031 struct ftrace_iterator
*iter
= m
->private;
3032 struct hlist_node
*hnd
= NULL
;
3033 struct hlist_head
*hhd
;
3039 hnd
= &iter
->probe
->node
;
3041 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
3044 hhd
= &ftrace_func_hash
[iter
->hidx
];
3046 if (hlist_empty(hhd
)) {
3062 if (WARN_ON_ONCE(!hnd
))
3065 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
3070 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
3072 struct ftrace_iterator
*iter
= m
->private;
3076 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
3079 if (iter
->func_pos
> *pos
)
3083 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
3084 p
= t_hash_next(m
, &l
);
3091 /* Only set this if we have an item */
3092 iter
->flags
|= FTRACE_ITER_HASH
;
3098 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
3100 struct ftrace_func_probe
*rec
;
3103 if (WARN_ON_ONCE(!rec
))
3106 if (rec
->ops
->print
)
3107 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
3109 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
3112 seq_printf(m
, ":%p", rec
->data
);
3119 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3121 struct ftrace_iterator
*iter
= m
->private;
3122 struct ftrace_ops
*ops
= iter
->ops
;
3123 struct dyn_ftrace
*rec
= NULL
;
3125 if (unlikely(ftrace_disabled
))
3128 if (iter
->flags
& FTRACE_ITER_HASH
)
3129 return t_hash_next(m
, pos
);
3132 iter
->pos
= iter
->func_pos
= *pos
;
3134 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
3135 return t_hash_start(m
, pos
);
3138 if (iter
->idx
>= iter
->pg
->index
) {
3139 if (iter
->pg
->next
) {
3140 iter
->pg
= iter
->pg
->next
;
3145 rec
= &iter
->pg
->records
[iter
->idx
++];
3146 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
3147 !(ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))) ||
3149 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
3150 !ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
)) ||
3152 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
3153 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
3161 return t_hash_start(m
, pos
);
3168 static void reset_iter_read(struct ftrace_iterator
*iter
)
3172 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
3175 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
3177 struct ftrace_iterator
*iter
= m
->private;
3178 struct ftrace_ops
*ops
= iter
->ops
;
3182 mutex_lock(&ftrace_lock
);
3184 if (unlikely(ftrace_disabled
))
3188 * If an lseek was done, then reset and start from beginning.
3190 if (*pos
< iter
->pos
)
3191 reset_iter_read(iter
);
3194 * For set_ftrace_filter reading, if we have the filter
3195 * off, we can short cut and just print out that all
3196 * functions are enabled.
3198 if ((iter
->flags
& FTRACE_ITER_FILTER
&&
3199 ftrace_hash_empty(ops
->func_hash
->filter_hash
)) ||
3200 (iter
->flags
& FTRACE_ITER_NOTRACE
&&
3201 ftrace_hash_empty(ops
->func_hash
->notrace_hash
))) {
3203 return t_hash_start(m
, pos
);
3204 iter
->flags
|= FTRACE_ITER_PRINTALL
;
3205 /* reset in case of seek/pread */
3206 iter
->flags
&= ~FTRACE_ITER_HASH
;
3210 if (iter
->flags
& FTRACE_ITER_HASH
)
3211 return t_hash_start(m
, pos
);
3214 * Unfortunately, we need to restart at ftrace_pages_start
3215 * every time we let go of the ftrace_mutex. This is because
3216 * those pointers can change without the lock.
3218 iter
->pg
= ftrace_pages_start
;
3220 for (l
= 0; l
<= *pos
; ) {
3221 p
= t_next(m
, p
, &l
);
3227 return t_hash_start(m
, pos
);
3232 static void t_stop(struct seq_file
*m
, void *p
)
3234 mutex_unlock(&ftrace_lock
);
3238 arch_ftrace_trampoline_func(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
3243 static void add_trampoline_func(struct seq_file
*m
, struct ftrace_ops
*ops
,
3244 struct dyn_ftrace
*rec
)
3248 ptr
= arch_ftrace_trampoline_func(ops
, rec
);
3250 seq_printf(m
, " ->%pS", ptr
);
3253 static int t_show(struct seq_file
*m
, void *v
)
3255 struct ftrace_iterator
*iter
= m
->private;
3256 struct dyn_ftrace
*rec
;
3258 if (iter
->flags
& FTRACE_ITER_HASH
)
3259 return t_hash_show(m
, iter
);
3261 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3262 if (iter
->flags
& FTRACE_ITER_NOTRACE
)
3263 seq_puts(m
, "#### no functions disabled ####\n");
3265 seq_puts(m
, "#### all functions enabled ####\n");
3274 seq_printf(m
, "%ps", (void *)rec
->ip
);
3275 if (iter
->flags
& FTRACE_ITER_ENABLED
) {
3276 struct ftrace_ops
*ops
;
3278 seq_printf(m
, " (%ld)%s%s",
3279 ftrace_rec_count(rec
),
3280 rec
->flags
& FTRACE_FL_REGS
? " R" : " ",
3281 rec
->flags
& FTRACE_FL_IPMODIFY
? " I" : " ");
3282 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
3283 ops
= ftrace_find_tramp_ops_any(rec
);
3286 seq_printf(m
, "\ttramp: %pS (%pS)",
3287 (void *)ops
->trampoline
,
3289 add_trampoline_func(m
, ops
, rec
);
3290 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
3293 seq_puts(m
, "\ttramp: ERROR!");
3295 add_trampoline_func(m
, NULL
, rec
);
3304 static const struct seq_operations show_ftrace_seq_ops
= {
3312 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
3314 struct ftrace_iterator
*iter
;
3316 if (unlikely(ftrace_disabled
))
3319 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3321 iter
->pg
= ftrace_pages_start
;
3322 iter
->ops
= &global_ops
;
3325 return iter
? 0 : -ENOMEM
;
3329 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
3331 struct ftrace_iterator
*iter
;
3333 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3335 iter
->pg
= ftrace_pages_start
;
3336 iter
->flags
= FTRACE_ITER_ENABLED
;
3337 iter
->ops
= &global_ops
;
3340 return iter
? 0 : -ENOMEM
;
3344 * ftrace_regex_open - initialize function tracer filter files
3345 * @ops: The ftrace_ops that hold the hash filters
3346 * @flag: The type of filter to process
3347 * @inode: The inode, usually passed in to your open routine
3348 * @file: The file, usually passed in to your open routine
3350 * ftrace_regex_open() initializes the filter files for the
3351 * @ops. Depending on @flag it may process the filter hash or
3352 * the notrace hash of @ops. With this called from the open
3353 * routine, you can use ftrace_filter_write() for the write
3354 * routine if @flag has FTRACE_ITER_FILTER set, or
3355 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3356 * tracing_lseek() should be used as the lseek routine, and
3357 * release must call ftrace_regex_release().
3360 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
3361 struct inode
*inode
, struct file
*file
)
3363 struct ftrace_iterator
*iter
;
3364 struct ftrace_hash
*hash
;
3367 ftrace_ops_init(ops
);
3369 if (unlikely(ftrace_disabled
))
3372 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
3376 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
3384 mutex_lock(&ops
->func_hash
->regex_lock
);
3386 if (flag
& FTRACE_ITER_NOTRACE
)
3387 hash
= ops
->func_hash
->notrace_hash
;
3389 hash
= ops
->func_hash
->filter_hash
;
3391 if (file
->f_mode
& FMODE_WRITE
) {
3392 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
3394 if (file
->f_flags
& O_TRUNC
)
3395 iter
->hash
= alloc_ftrace_hash(size_bits
);
3397 iter
->hash
= alloc_and_copy_ftrace_hash(size_bits
, hash
);
3400 trace_parser_put(&iter
->parser
);
3407 if (file
->f_mode
& FMODE_READ
) {
3408 iter
->pg
= ftrace_pages_start
;
3410 ret
= seq_open(file
, &show_ftrace_seq_ops
);
3412 struct seq_file
*m
= file
->private_data
;
3416 free_ftrace_hash(iter
->hash
);
3417 trace_parser_put(&iter
->parser
);
3421 file
->private_data
= iter
;
3424 mutex_unlock(&ops
->func_hash
->regex_lock
);
3430 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
3432 struct ftrace_ops
*ops
= inode
->i_private
;
3434 return ftrace_regex_open(ops
,
3435 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
3440 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
3442 struct ftrace_ops
*ops
= inode
->i_private
;
3444 return ftrace_regex_open(ops
, FTRACE_ITER_NOTRACE
,
3448 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3449 struct ftrace_glob
{
3455 static int ftrace_match(char *str
, struct ftrace_glob
*g
)
3462 if (strcmp(str
, g
->search
) == 0)
3465 case MATCH_FRONT_ONLY
:
3466 if (strncmp(str
, g
->search
, g
->len
) == 0)
3469 case MATCH_MIDDLE_ONLY
:
3470 if (strstr(str
, g
->search
))
3473 case MATCH_END_ONLY
:
3475 if (slen
>= g
->len
&&
3476 memcmp(str
+ slen
- g
->len
, g
->search
, g
->len
) == 0)
3485 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int clear_filter
)
3487 struct ftrace_func_entry
*entry
;
3490 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
3492 /* Do nothing if it doesn't exist */
3496 free_hash_entry(hash
, entry
);
3498 /* Do nothing if it exists */
3502 ret
= add_hash_entry(hash
, rec
->ip
);
3508 ftrace_match_record(struct dyn_ftrace
*rec
, struct ftrace_glob
*func_g
,
3509 struct ftrace_glob
*mod_g
, int exclude_mod
)
3511 char str
[KSYM_SYMBOL_LEN
];
3514 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
3517 int mod_matches
= (modname
) ? ftrace_match(modname
, mod_g
) : 0;
3519 /* blank module name to match all modules */
3521 /* blank module globbing: modname xor exclude_mod */
3522 if ((!exclude_mod
) != (!modname
))
3527 /* not matching the module */
3528 if (!modname
|| !mod_matches
) {
3535 if (mod_matches
&& exclude_mod
)
3539 /* blank search means to match all funcs in the mod */
3544 return ftrace_match(str
, func_g
);
3548 match_records(struct ftrace_hash
*hash
, char *func
, int len
, char *mod
)
3550 struct ftrace_page
*pg
;
3551 struct dyn_ftrace
*rec
;
3552 struct ftrace_glob func_g
= { .type
= MATCH_FULL
};
3553 struct ftrace_glob mod_g
= { .type
= MATCH_FULL
};
3554 struct ftrace_glob
*mod_match
= (mod
) ? &mod_g
: NULL
;
3555 int exclude_mod
= 0;
3561 func_g
.type
= filter_parse_regex(func
, len
, &func_g
.search
,
3563 func_g
.len
= strlen(func_g
.search
);
3567 mod_g
.type
= filter_parse_regex(mod
, strlen(mod
),
3568 &mod_g
.search
, &exclude_mod
);
3569 mod_g
.len
= strlen(mod_g
.search
);
3572 mutex_lock(&ftrace_lock
);
3574 if (unlikely(ftrace_disabled
))
3577 do_for_each_ftrace_rec(pg
, rec
) {
3578 if (ftrace_match_record(rec
, &func_g
, mod_match
, exclude_mod
)) {
3579 ret
= enter_record(hash
, rec
, clear_filter
);
3586 } while_for_each_ftrace_rec();
3588 mutex_unlock(&ftrace_lock
);
3594 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
3596 return match_records(hash
, buff
, len
, NULL
);
3601 * We register the module command as a template to show others how
3602 * to register the a command as well.
3606 ftrace_mod_callback(struct ftrace_hash
*hash
,
3607 char *func
, char *cmd
, char *module
, int enable
)
3612 * cmd == 'mod' because we only registered this func
3613 * for the 'mod' ftrace_func_command.
3614 * But if you register one func with multiple commands,
3615 * you can tell which command was used by the cmd
3618 ret
= match_records(hash
, func
, strlen(func
), module
);
3626 static struct ftrace_func_command ftrace_mod_cmd
= {
3628 .func
= ftrace_mod_callback
,
3631 static int __init
ftrace_mod_cmd_init(void)
3633 return register_ftrace_command(&ftrace_mod_cmd
);
3635 core_initcall(ftrace_mod_cmd_init
);
3637 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
3638 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3640 struct ftrace_func_probe
*entry
;
3641 struct hlist_head
*hhd
;
3644 key
= hash_long(ip
, FTRACE_HASH_BITS
);
3646 hhd
= &ftrace_func_hash
[key
];
3648 if (hlist_empty(hhd
))
3652 * Disable preemption for these calls to prevent a RCU grace
3653 * period. This syncs the hash iteration and freeing of items
3654 * on the hash. rcu_read_lock is too dangerous here.
3656 preempt_disable_notrace();
3657 hlist_for_each_entry_rcu_notrace(entry
, hhd
, node
) {
3658 if (entry
->ip
== ip
)
3659 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
3661 preempt_enable_notrace();
3664 static struct ftrace_ops trace_probe_ops __read_mostly
=
3666 .func
= function_trace_probe_call
,
3667 .flags
= FTRACE_OPS_FL_INITIALIZED
,
3668 INIT_OPS_HASH(trace_probe_ops
)
3671 static int ftrace_probe_registered
;
3673 static void __enable_ftrace_function_probe(struct ftrace_ops_hash
*old_hash
)
3678 if (ftrace_probe_registered
) {
3679 /* still need to update the function call sites */
3681 ftrace_run_modify_code(&trace_probe_ops
, FTRACE_UPDATE_CALLS
,
3686 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3687 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3691 /* Nothing registered? */
3692 if (i
== FTRACE_FUNC_HASHSIZE
)
3695 ret
= ftrace_startup(&trace_probe_ops
, 0);
3697 ftrace_probe_registered
= 1;
3700 static void __disable_ftrace_function_probe(void)
3704 if (!ftrace_probe_registered
)
3707 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3708 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3713 /* no more funcs left */
3714 ftrace_shutdown(&trace_probe_ops
, 0);
3716 ftrace_probe_registered
= 0;
3720 static void ftrace_free_entry(struct ftrace_func_probe
*entry
)
3722 if (entry
->ops
->free
)
3723 entry
->ops
->free(entry
->ops
, entry
->ip
, &entry
->data
);
3728 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3731 struct ftrace_ops_hash old_hash_ops
;
3732 struct ftrace_func_probe
*entry
;
3733 struct ftrace_glob func_g
;
3734 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3735 struct ftrace_hash
*old_hash
= *orig_hash
;
3736 struct ftrace_hash
*hash
;
3737 struct ftrace_page
*pg
;
3738 struct dyn_ftrace
*rec
;
3744 func_g
.type
= filter_parse_regex(glob
, strlen(glob
),
3745 &func_g
.search
, ¬);
3746 func_g
.len
= strlen(func_g
.search
);
3748 /* we do not support '!' for function probes */
3752 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3754 old_hash_ops
.filter_hash
= old_hash
;
3755 /* Probes only have filters */
3756 old_hash_ops
.notrace_hash
= NULL
;
3758 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
3764 if (unlikely(ftrace_disabled
)) {
3769 mutex_lock(&ftrace_lock
);
3771 do_for_each_ftrace_rec(pg
, rec
) {
3773 if (!ftrace_match_record(rec
, &func_g
, NULL
, 0))
3776 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3778 /* If we did not process any, then return error */
3789 * The caller might want to do something special
3790 * for each function we find. We call the callback
3791 * to give the caller an opportunity to do so.
3794 if (ops
->init(ops
, rec
->ip
, &entry
->data
) < 0) {
3795 /* caller does not like this func */
3801 ret
= enter_record(hash
, rec
, 0);
3809 entry
->ip
= rec
->ip
;
3811 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3812 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3814 } while_for_each_ftrace_rec();
3816 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3818 __enable_ftrace_function_probe(&old_hash_ops
);
3821 free_ftrace_hash_rcu(old_hash
);
3826 mutex_unlock(&ftrace_lock
);
3828 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3829 free_ftrace_hash(hash
);
3835 PROBE_TEST_FUNC
= 1,
3840 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3841 void *data
, int flags
)
3843 struct ftrace_func_entry
*rec_entry
;
3844 struct ftrace_func_probe
*entry
;
3845 struct ftrace_func_probe
*p
;
3846 struct ftrace_glob func_g
;
3847 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3848 struct ftrace_hash
*old_hash
= *orig_hash
;
3849 struct list_head free_list
;
3850 struct ftrace_hash
*hash
;
3851 struct hlist_node
*tmp
;
3852 char str
[KSYM_SYMBOL_LEN
];
3855 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3856 func_g
.search
= NULL
;
3860 func_g
.type
= filter_parse_regex(glob
, strlen(glob
),
3861 &func_g
.search
, ¬);
3862 func_g
.len
= strlen(func_g
.search
);
3863 func_g
.search
= glob
;
3865 /* we do not support '!' for function probes */
3870 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3872 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3874 /* Hmm, should report this somehow */
3877 INIT_LIST_HEAD(&free_list
);
3879 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3880 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3882 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3884 /* break up if statements for readability */
3885 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3888 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3891 /* do this last, since it is the most expensive */
3892 if (func_g
.search
) {
3893 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3895 if (!ftrace_match(str
, &func_g
))
3899 rec_entry
= ftrace_lookup_ip(hash
, entry
->ip
);
3900 /* It is possible more than one entry had this ip */
3902 free_hash_entry(hash
, rec_entry
);
3904 hlist_del_rcu(&entry
->node
);
3905 list_add(&entry
->free_list
, &free_list
);
3908 mutex_lock(&ftrace_lock
);
3909 __disable_ftrace_function_probe();
3911 * Remove after the disable is called. Otherwise, if the last
3912 * probe is removed, a null hash means *all enabled*.
3914 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3915 synchronize_sched();
3917 free_ftrace_hash_rcu(old_hash
);
3919 list_for_each_entry_safe(entry
, p
, &free_list
, free_list
) {
3920 list_del(&entry
->free_list
);
3921 ftrace_free_entry(entry
);
3923 mutex_unlock(&ftrace_lock
);
3926 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3927 free_ftrace_hash(hash
);
3931 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3934 __unregister_ftrace_function_probe(glob
, ops
, data
,
3935 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3939 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3941 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3944 void unregister_ftrace_function_probe_all(char *glob
)
3946 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3949 static LIST_HEAD(ftrace_commands
);
3950 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3953 * Currently we only register ftrace commands from __init, so mark this
3956 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
3958 struct ftrace_func_command
*p
;
3961 mutex_lock(&ftrace_cmd_mutex
);
3962 list_for_each_entry(p
, &ftrace_commands
, list
) {
3963 if (strcmp(cmd
->name
, p
->name
) == 0) {
3968 list_add(&cmd
->list
, &ftrace_commands
);
3970 mutex_unlock(&ftrace_cmd_mutex
);
3976 * Currently we only unregister ftrace commands from __init, so mark
3979 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
3981 struct ftrace_func_command
*p
, *n
;
3984 mutex_lock(&ftrace_cmd_mutex
);
3985 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
3986 if (strcmp(cmd
->name
, p
->name
) == 0) {
3988 list_del_init(&p
->list
);
3993 mutex_unlock(&ftrace_cmd_mutex
);
3998 static int ftrace_process_regex(struct ftrace_hash
*hash
,
3999 char *buff
, int len
, int enable
)
4001 char *func
, *command
, *next
= buff
;
4002 struct ftrace_func_command
*p
;
4005 func
= strsep(&next
, ":");
4008 ret
= ftrace_match_records(hash
, func
, len
);
4018 command
= strsep(&next
, ":");
4020 mutex_lock(&ftrace_cmd_mutex
);
4021 list_for_each_entry(p
, &ftrace_commands
, list
) {
4022 if (strcmp(p
->name
, command
) == 0) {
4023 ret
= p
->func(hash
, func
, command
, next
, enable
);
4028 mutex_unlock(&ftrace_cmd_mutex
);
4034 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
4035 size_t cnt
, loff_t
*ppos
, int enable
)
4037 struct ftrace_iterator
*iter
;
4038 struct trace_parser
*parser
;
4044 if (file
->f_mode
& FMODE_READ
) {
4045 struct seq_file
*m
= file
->private_data
;
4048 iter
= file
->private_data
;
4050 if (unlikely(ftrace_disabled
))
4053 /* iter->hash is a local copy, so we don't need regex_lock */
4055 parser
= &iter
->parser
;
4056 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
4058 if (read
>= 0 && trace_parser_loaded(parser
) &&
4059 !trace_parser_cont(parser
)) {
4060 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
4061 parser
->idx
, enable
);
4062 trace_parser_clear(parser
);
4073 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
4074 size_t cnt
, loff_t
*ppos
)
4076 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
4080 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
4081 size_t cnt
, loff_t
*ppos
)
4083 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
4087 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
4089 struct ftrace_func_entry
*entry
;
4091 if (!ftrace_location(ip
))
4095 entry
= ftrace_lookup_ip(hash
, ip
);
4098 free_hash_entry(hash
, entry
);
4102 return add_hash_entry(hash
, ip
);
4105 static void ftrace_ops_update_code(struct ftrace_ops
*ops
,
4106 struct ftrace_ops_hash
*old_hash
)
4108 struct ftrace_ops
*op
;
4110 if (!ftrace_enabled
)
4113 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
4114 ftrace_run_modify_code(ops
, FTRACE_UPDATE_CALLS
, old_hash
);
4119 * If this is the shared global_ops filter, then we need to
4120 * check if there is another ops that shares it, is enabled.
4121 * If so, we still need to run the modify code.
4123 if (ops
->func_hash
!= &global_ops
.local_hash
)
4126 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4127 if (op
->func_hash
== &global_ops
.local_hash
&&
4128 op
->flags
& FTRACE_OPS_FL_ENABLED
) {
4129 ftrace_run_modify_code(op
, FTRACE_UPDATE_CALLS
, old_hash
);
4130 /* Only need to do this once */
4133 } while_for_each_ftrace_op(op
);
4137 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4138 unsigned long ip
, int remove
, int reset
, int enable
)
4140 struct ftrace_hash
**orig_hash
;
4141 struct ftrace_ops_hash old_hash_ops
;
4142 struct ftrace_hash
*old_hash
;
4143 struct ftrace_hash
*hash
;
4146 if (unlikely(ftrace_disabled
))
4149 mutex_lock(&ops
->func_hash
->regex_lock
);
4152 orig_hash
= &ops
->func_hash
->filter_hash
;
4154 orig_hash
= &ops
->func_hash
->notrace_hash
;
4157 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4159 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
4163 goto out_regex_unlock
;
4166 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
4168 goto out_regex_unlock
;
4171 ret
= ftrace_match_addr(hash
, ip
, remove
);
4173 goto out_regex_unlock
;
4176 mutex_lock(&ftrace_lock
);
4177 old_hash
= *orig_hash
;
4178 old_hash_ops
.filter_hash
= ops
->func_hash
->filter_hash
;
4179 old_hash_ops
.notrace_hash
= ops
->func_hash
->notrace_hash
;
4180 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
4182 ftrace_ops_update_code(ops
, &old_hash_ops
);
4183 free_ftrace_hash_rcu(old_hash
);
4185 mutex_unlock(&ftrace_lock
);
4188 mutex_unlock(&ops
->func_hash
->regex_lock
);
4190 free_ftrace_hash(hash
);
4195 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
4196 int reset
, int enable
)
4198 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
4202 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4203 * @ops - the ops to set the filter with
4204 * @ip - the address to add to or remove from the filter.
4205 * @remove - non zero to remove the ip from the filter
4206 * @reset - non zero to reset all filters before applying this filter.
4208 * Filters denote which functions should be enabled when tracing is enabled
4209 * If @ip is NULL, it failes to update filter.
4211 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
4212 int remove
, int reset
)
4214 ftrace_ops_init(ops
);
4215 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
4217 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
4220 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4221 int reset
, int enable
)
4223 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
4227 * ftrace_set_filter - set a function to filter on in ftrace
4228 * @ops - the ops to set the filter with
4229 * @buf - the string that holds the function filter text.
4230 * @len - the length of the string.
4231 * @reset - non zero to reset all filters before applying this filter.
4233 * Filters denote which functions should be enabled when tracing is enabled.
4234 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4236 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
4239 ftrace_ops_init(ops
);
4240 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
4242 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
4245 * ftrace_set_notrace - set a function to not trace in ftrace
4246 * @ops - the ops to set the notrace filter with
4247 * @buf - the string that holds the function notrace text.
4248 * @len - the length of the string.
4249 * @reset - non zero to reset all filters before applying this filter.
4251 * Notrace Filters denote which functions should not be enabled when tracing
4252 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4255 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
4258 ftrace_ops_init(ops
);
4259 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
4261 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
4263 * ftrace_set_global_filter - set a function to filter on with global tracers
4264 * @buf - the string that holds the function filter text.
4265 * @len - the length of the string.
4266 * @reset - non zero to reset all filters before applying this filter.
4268 * Filters denote which functions should be enabled when tracing is enabled.
4269 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4271 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
4273 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
4275 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
4278 * ftrace_set_global_notrace - set a function to not trace with global tracers
4279 * @buf - the string that holds the function notrace text.
4280 * @len - the length of the string.
4281 * @reset - non zero to reset all filters before applying this filter.
4283 * Notrace Filters denote which functions should not be enabled when tracing
4284 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4287 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
4289 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
4291 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
4294 * command line interface to allow users to set filters on boot up.
4296 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4297 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4298 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4300 /* Used by function selftest to not test if filter is set */
4301 bool ftrace_filter_param __initdata
;
4303 static int __init
set_ftrace_notrace(char *str
)
4305 ftrace_filter_param
= true;
4306 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4309 __setup("ftrace_notrace=", set_ftrace_notrace
);
4311 static int __init
set_ftrace_filter(char *str
)
4313 ftrace_filter_param
= true;
4314 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
4317 __setup("ftrace_filter=", set_ftrace_filter
);
4319 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4320 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4321 static char ftrace_graph_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4322 static int ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
);
4324 static unsigned long save_global_trampoline
;
4325 static unsigned long save_global_flags
;
4327 static int __init
set_graph_function(char *str
)
4329 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
4332 __setup("ftrace_graph_filter=", set_graph_function
);
4334 static int __init
set_graph_notrace_function(char *str
)
4336 strlcpy(ftrace_graph_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4339 __setup("ftrace_graph_notrace=", set_graph_notrace_function
);
4341 static void __init
set_ftrace_early_graph(char *buf
, int enable
)
4345 unsigned long *table
= ftrace_graph_funcs
;
4346 int *count
= &ftrace_graph_count
;
4349 table
= ftrace_graph_notrace_funcs
;
4350 count
= &ftrace_graph_notrace_count
;
4354 func
= strsep(&buf
, ",");
4355 /* we allow only one expression at a time */
4356 ret
= ftrace_set_func(table
, count
, FTRACE_GRAPH_MAX_FUNCS
, func
);
4358 printk(KERN_DEBUG
"ftrace: function %s not "
4359 "traceable\n", func
);
4362 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4365 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
4369 ftrace_ops_init(ops
);
4372 func
= strsep(&buf
, ",");
4373 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
4377 static void __init
set_ftrace_early_filters(void)
4379 if (ftrace_filter_buf
[0])
4380 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
4381 if (ftrace_notrace_buf
[0])
4382 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
4383 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4384 if (ftrace_graph_buf
[0])
4385 set_ftrace_early_graph(ftrace_graph_buf
, 1);
4386 if (ftrace_graph_notrace_buf
[0])
4387 set_ftrace_early_graph(ftrace_graph_notrace_buf
, 0);
4388 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4391 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
4393 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
4394 struct ftrace_ops_hash old_hash_ops
;
4395 struct ftrace_iterator
*iter
;
4396 struct ftrace_hash
**orig_hash
;
4397 struct ftrace_hash
*old_hash
;
4398 struct trace_parser
*parser
;
4402 if (file
->f_mode
& FMODE_READ
) {
4404 seq_release(inode
, file
);
4406 iter
= file
->private_data
;
4408 parser
= &iter
->parser
;
4409 if (trace_parser_loaded(parser
)) {
4410 parser
->buffer
[parser
->idx
] = 0;
4411 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
4414 trace_parser_put(parser
);
4416 mutex_lock(&iter
->ops
->func_hash
->regex_lock
);
4418 if (file
->f_mode
& FMODE_WRITE
) {
4419 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
4422 orig_hash
= &iter
->ops
->func_hash
->filter_hash
;
4424 orig_hash
= &iter
->ops
->func_hash
->notrace_hash
;
4426 mutex_lock(&ftrace_lock
);
4427 old_hash
= *orig_hash
;
4428 old_hash_ops
.filter_hash
= iter
->ops
->func_hash
->filter_hash
;
4429 old_hash_ops
.notrace_hash
= iter
->ops
->func_hash
->notrace_hash
;
4430 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
4431 orig_hash
, iter
->hash
);
4433 ftrace_ops_update_code(iter
->ops
, &old_hash_ops
);
4434 free_ftrace_hash_rcu(old_hash
);
4436 mutex_unlock(&ftrace_lock
);
4439 mutex_unlock(&iter
->ops
->func_hash
->regex_lock
);
4440 free_ftrace_hash(iter
->hash
);
4446 static const struct file_operations ftrace_avail_fops
= {
4447 .open
= ftrace_avail_open
,
4449 .llseek
= seq_lseek
,
4450 .release
= seq_release_private
,
4453 static const struct file_operations ftrace_enabled_fops
= {
4454 .open
= ftrace_enabled_open
,
4456 .llseek
= seq_lseek
,
4457 .release
= seq_release_private
,
4460 static const struct file_operations ftrace_filter_fops
= {
4461 .open
= ftrace_filter_open
,
4463 .write
= ftrace_filter_write
,
4464 .llseek
= tracing_lseek
,
4465 .release
= ftrace_regex_release
,
4468 static const struct file_operations ftrace_notrace_fops
= {
4469 .open
= ftrace_notrace_open
,
4471 .write
= ftrace_notrace_write
,
4472 .llseek
= tracing_lseek
,
4473 .release
= ftrace_regex_release
,
4476 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4478 static DEFINE_MUTEX(graph_lock
);
4480 int ftrace_graph_count
;
4481 int ftrace_graph_notrace_count
;
4482 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4483 unsigned long ftrace_graph_notrace_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4485 struct ftrace_graph_data
{
4486 unsigned long *table
;
4489 const struct seq_operations
*seq_ops
;
4493 __g_next(struct seq_file
*m
, loff_t
*pos
)
4495 struct ftrace_graph_data
*fgd
= m
->private;
4497 if (*pos
>= *fgd
->count
)
4499 return &fgd
->table
[*pos
];
4503 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4506 return __g_next(m
, pos
);
4509 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
4511 struct ftrace_graph_data
*fgd
= m
->private;
4513 mutex_lock(&graph_lock
);
4515 /* Nothing, tell g_show to print all functions are enabled */
4516 if (!*fgd
->count
&& !*pos
)
4519 return __g_next(m
, pos
);
4522 static void g_stop(struct seq_file
*m
, void *p
)
4524 mutex_unlock(&graph_lock
);
4527 static int g_show(struct seq_file
*m
, void *v
)
4529 unsigned long *ptr
= v
;
4534 if (ptr
== (unsigned long *)1) {
4535 struct ftrace_graph_data
*fgd
= m
->private;
4537 if (fgd
->table
== ftrace_graph_funcs
)
4538 seq_puts(m
, "#### all functions enabled ####\n");
4540 seq_puts(m
, "#### no functions disabled ####\n");
4544 seq_printf(m
, "%ps\n", (void *)*ptr
);
4549 static const struct seq_operations ftrace_graph_seq_ops
= {
4557 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
4558 struct ftrace_graph_data
*fgd
)
4562 mutex_lock(&graph_lock
);
4563 if ((file
->f_mode
& FMODE_WRITE
) &&
4564 (file
->f_flags
& O_TRUNC
)) {
4566 memset(fgd
->table
, 0, fgd
->size
* sizeof(*fgd
->table
));
4568 mutex_unlock(&graph_lock
);
4570 if (file
->f_mode
& FMODE_READ
) {
4571 ret
= seq_open(file
, fgd
->seq_ops
);
4573 struct seq_file
*m
= file
->private_data
;
4577 file
->private_data
= fgd
;
4583 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
4585 struct ftrace_graph_data
*fgd
;
4587 if (unlikely(ftrace_disabled
))
4590 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4594 fgd
->table
= ftrace_graph_funcs
;
4595 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4596 fgd
->count
= &ftrace_graph_count
;
4597 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4599 return __ftrace_graph_open(inode
, file
, fgd
);
4603 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
4605 struct ftrace_graph_data
*fgd
;
4607 if (unlikely(ftrace_disabled
))
4610 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4614 fgd
->table
= ftrace_graph_notrace_funcs
;
4615 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4616 fgd
->count
= &ftrace_graph_notrace_count
;
4617 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4619 return __ftrace_graph_open(inode
, file
, fgd
);
4623 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
4625 if (file
->f_mode
& FMODE_READ
) {
4626 struct seq_file
*m
= file
->private_data
;
4629 seq_release(inode
, file
);
4631 kfree(file
->private_data
);
4638 ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
)
4640 struct ftrace_glob func_g
;
4641 struct dyn_ftrace
*rec
;
4642 struct ftrace_page
*pg
;
4649 func_g
.type
= filter_parse_regex(buffer
, strlen(buffer
),
4650 &func_g
.search
, ¬);
4651 if (!not && *idx
>= size
)
4654 func_g
.len
= strlen(func_g
.search
);
4656 mutex_lock(&ftrace_lock
);
4658 if (unlikely(ftrace_disabled
)) {
4659 mutex_unlock(&ftrace_lock
);
4663 do_for_each_ftrace_rec(pg
, rec
) {
4665 if (ftrace_match_record(rec
, &func_g
, NULL
, 0)) {
4666 /* if it is in the array */
4668 for (i
= 0; i
< *idx
; i
++) {
4669 if (array
[i
] == rec
->ip
) {
4678 array
[(*idx
)++] = rec
->ip
;
4684 array
[i
] = array
[--(*idx
)];
4690 } while_for_each_ftrace_rec();
4692 mutex_unlock(&ftrace_lock
);
4701 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
4702 size_t cnt
, loff_t
*ppos
)
4704 struct trace_parser parser
;
4705 ssize_t read
, ret
= 0;
4706 struct ftrace_graph_data
*fgd
= file
->private_data
;
4711 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
))
4714 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
4716 if (read
>= 0 && trace_parser_loaded((&parser
))) {
4717 parser
.buffer
[parser
.idx
] = 0;
4719 mutex_lock(&graph_lock
);
4721 /* we allow only one expression at a time */
4722 ret
= ftrace_set_func(fgd
->table
, fgd
->count
, fgd
->size
,
4725 mutex_unlock(&graph_lock
);
4731 trace_parser_put(&parser
);
4736 static const struct file_operations ftrace_graph_fops
= {
4737 .open
= ftrace_graph_open
,
4739 .write
= ftrace_graph_write
,
4740 .llseek
= tracing_lseek
,
4741 .release
= ftrace_graph_release
,
4744 static const struct file_operations ftrace_graph_notrace_fops
= {
4745 .open
= ftrace_graph_notrace_open
,
4747 .write
= ftrace_graph_write
,
4748 .llseek
= tracing_lseek
,
4749 .release
= ftrace_graph_release
,
4751 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4753 void ftrace_create_filter_files(struct ftrace_ops
*ops
,
4754 struct dentry
*parent
)
4757 trace_create_file("set_ftrace_filter", 0644, parent
,
4758 ops
, &ftrace_filter_fops
);
4760 trace_create_file("set_ftrace_notrace", 0644, parent
,
4761 ops
, &ftrace_notrace_fops
);
4765 * The name "destroy_filter_files" is really a misnomer. Although
4766 * in the future, it may actualy delete the files, but this is
4767 * really intended to make sure the ops passed in are disabled
4768 * and that when this function returns, the caller is free to
4771 * The "destroy" name is only to match the "create" name that this
4772 * should be paired with.
4774 void ftrace_destroy_filter_files(struct ftrace_ops
*ops
)
4776 mutex_lock(&ftrace_lock
);
4777 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
)
4778 ftrace_shutdown(ops
, 0);
4779 ops
->flags
|= FTRACE_OPS_FL_DELETED
;
4780 mutex_unlock(&ftrace_lock
);
4783 static __init
int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
)
4786 trace_create_file("available_filter_functions", 0444,
4787 d_tracer
, NULL
, &ftrace_avail_fops
);
4789 trace_create_file("enabled_functions", 0444,
4790 d_tracer
, NULL
, &ftrace_enabled_fops
);
4792 ftrace_create_filter_files(&global_ops
, d_tracer
);
4794 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4795 trace_create_file("set_graph_function", 0444, d_tracer
,
4797 &ftrace_graph_fops
);
4798 trace_create_file("set_graph_notrace", 0444, d_tracer
,
4800 &ftrace_graph_notrace_fops
);
4801 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4806 static int ftrace_cmp_ips(const void *a
, const void *b
)
4808 const unsigned long *ipa
= a
;
4809 const unsigned long *ipb
= b
;
4818 static int ftrace_process_locs(struct module
*mod
,
4819 unsigned long *start
,
4822 struct ftrace_page
*start_pg
;
4823 struct ftrace_page
*pg
;
4824 struct dyn_ftrace
*rec
;
4825 unsigned long count
;
4828 unsigned long flags
= 0; /* Shut up gcc */
4831 count
= end
- start
;
4836 sort(start
, count
, sizeof(*start
),
4837 ftrace_cmp_ips
, NULL
);
4839 start_pg
= ftrace_allocate_pages(count
);
4843 mutex_lock(&ftrace_lock
);
4846 * Core and each module needs their own pages, as
4847 * modules will free them when they are removed.
4848 * Force a new page to be allocated for modules.
4851 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
4852 /* First initialization */
4853 ftrace_pages
= ftrace_pages_start
= start_pg
;
4858 if (WARN_ON(ftrace_pages
->next
)) {
4859 /* Hmm, we have free pages? */
4860 while (ftrace_pages
->next
)
4861 ftrace_pages
= ftrace_pages
->next
;
4864 ftrace_pages
->next
= start_pg
;
4870 addr
= ftrace_call_adjust(*p
++);
4872 * Some architecture linkers will pad between
4873 * the different mcount_loc sections of different
4874 * object files to satisfy alignments.
4875 * Skip any NULL pointers.
4880 if (pg
->index
== pg
->size
) {
4881 /* We should have allocated enough */
4882 if (WARN_ON(!pg
->next
))
4887 rec
= &pg
->records
[pg
->index
++];
4891 /* We should have used all pages */
4894 /* Assign the last page to ftrace_pages */
4898 * We only need to disable interrupts on start up
4899 * because we are modifying code that an interrupt
4900 * may execute, and the modification is not atomic.
4901 * But for modules, nothing runs the code we modify
4902 * until we are finished with it, and there's no
4903 * reason to cause large interrupt latencies while we do it.
4906 local_irq_save(flags
);
4907 ftrace_update_code(mod
, start_pg
);
4909 local_irq_restore(flags
);
4912 mutex_unlock(&ftrace_lock
);
4917 #ifdef CONFIG_MODULES
4919 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4921 static int referenced_filters(struct dyn_ftrace
*rec
)
4923 struct ftrace_ops
*ops
;
4926 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
4927 if (ops_references_rec(ops
, rec
))
4934 void ftrace_release_mod(struct module
*mod
)
4936 struct dyn_ftrace
*rec
;
4937 struct ftrace_page
**last_pg
;
4938 struct ftrace_page
*pg
;
4941 mutex_lock(&ftrace_lock
);
4943 if (ftrace_disabled
)
4947 * Each module has its own ftrace_pages, remove
4948 * them from the list.
4950 last_pg
= &ftrace_pages_start
;
4951 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
4952 rec
= &pg
->records
[0];
4953 if (within_module_core(rec
->ip
, mod
)) {
4955 * As core pages are first, the first
4956 * page should never be a module page.
4958 if (WARN_ON(pg
== ftrace_pages_start
))
4961 /* Check if we are deleting the last page */
4962 if (pg
== ftrace_pages
)
4963 ftrace_pages
= next_to_ftrace_page(last_pg
);
4965 *last_pg
= pg
->next
;
4966 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
4967 free_pages((unsigned long)pg
->records
, order
);
4970 last_pg
= &pg
->next
;
4973 mutex_unlock(&ftrace_lock
);
4976 void ftrace_module_enable(struct module
*mod
)
4978 struct dyn_ftrace
*rec
;
4979 struct ftrace_page
*pg
;
4981 mutex_lock(&ftrace_lock
);
4983 if (ftrace_disabled
)
4987 * If the tracing is enabled, go ahead and enable the record.
4989 * The reason not to enable the record immediatelly is the
4990 * inherent check of ftrace_make_nop/ftrace_make_call for
4991 * correct previous instructions. Making first the NOP
4992 * conversion puts the module to the correct state, thus
4993 * passing the ftrace_make_call check.
4995 * We also delay this to after the module code already set the
4996 * text to read-only, as we now need to set it back to read-write
4997 * so that we can modify the text.
4999 if (ftrace_start_up
)
5000 ftrace_arch_code_modify_prepare();
5002 do_for_each_ftrace_rec(pg
, rec
) {
5005 * do_for_each_ftrace_rec() is a double loop.
5006 * module text shares the pg. If a record is
5007 * not part of this module, then skip this pg,
5008 * which the "break" will do.
5010 if (!within_module_core(rec
->ip
, mod
))
5016 * When adding a module, we need to check if tracers are
5017 * currently enabled and if they are, and can trace this record,
5018 * we need to enable the module functions as well as update the
5019 * reference counts for those function records.
5021 if (ftrace_start_up
)
5022 cnt
+= referenced_filters(rec
);
5024 /* This clears FTRACE_FL_DISABLED */
5027 if (ftrace_start_up
&& cnt
) {
5028 int failed
= __ftrace_replace_code(rec
, 1);
5030 ftrace_bug(failed
, rec
);
5035 } while_for_each_ftrace_rec();
5038 if (ftrace_start_up
)
5039 ftrace_arch_code_modify_post_process();
5042 mutex_unlock(&ftrace_lock
);
5045 void ftrace_module_init(struct module
*mod
)
5047 if (ftrace_disabled
|| !mod
->num_ftrace_callsites
)
5050 ftrace_process_locs(mod
, mod
->ftrace_callsites
,
5051 mod
->ftrace_callsites
+ mod
->num_ftrace_callsites
);
5053 #endif /* CONFIG_MODULES */
5055 void __init
ftrace_init(void)
5057 extern unsigned long __start_mcount_loc
[];
5058 extern unsigned long __stop_mcount_loc
[];
5059 unsigned long count
, flags
;
5062 local_irq_save(flags
);
5063 ret
= ftrace_dyn_arch_init();
5064 local_irq_restore(flags
);
5068 count
= __stop_mcount_loc
- __start_mcount_loc
;
5070 pr_info("ftrace: No functions to be traced?\n");
5074 pr_info("ftrace: allocating %ld entries in %ld pages\n",
5075 count
, count
/ ENTRIES_PER_PAGE
+ 1);
5077 last_ftrace_enabled
= ftrace_enabled
= 1;
5079 ret
= ftrace_process_locs(NULL
,
5083 set_ftrace_early_filters();
5087 ftrace_disabled
= 1;
5090 /* Do nothing if arch does not support this */
5091 void __weak
arch_ftrace_update_trampoline(struct ftrace_ops
*ops
)
5095 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5099 * Currently there's no safe way to free a trampoline when the kernel
5100 * is configured with PREEMPT. That is because a task could be preempted
5101 * when it jumped to the trampoline, it may be preempted for a long time
5102 * depending on the system load, and currently there's no way to know
5103 * when it will be off the trampoline. If the trampoline is freed
5104 * too early, when the task runs again, it will be executing on freed
5107 #ifdef CONFIG_PREEMPT
5108 /* Currently, only non dynamic ops can have a trampoline */
5109 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
)
5113 arch_ftrace_update_trampoline(ops
);
5118 static struct ftrace_ops global_ops
= {
5119 .func
= ftrace_stub
,
5120 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5121 FTRACE_OPS_FL_INITIALIZED
|
5125 static int __init
ftrace_nodyn_init(void)
5130 core_initcall(ftrace_nodyn_init
);
5132 static inline int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
) { return 0; }
5133 static inline void ftrace_startup_enable(int command
) { }
5134 static inline void ftrace_startup_all(int command
) { }
5135 /* Keep as macros so we do not need to define the commands */
5136 # define ftrace_startup(ops, command) \
5138 int ___ret = __register_ftrace_function(ops); \
5140 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
5143 # define ftrace_shutdown(ops, command) \
5145 int ___ret = __unregister_ftrace_function(ops); \
5147 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
5151 # define ftrace_startup_sysctl() do { } while (0)
5152 # define ftrace_shutdown_sysctl() do { } while (0)
5155 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
5160 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
5164 #endif /* CONFIG_DYNAMIC_FTRACE */
5166 __init
void ftrace_init_global_array_ops(struct trace_array
*tr
)
5168 tr
->ops
= &global_ops
;
5169 tr
->ops
->private = tr
;
5172 void ftrace_init_array_ops(struct trace_array
*tr
, ftrace_func_t func
)
5174 /* If we filter on pids, update to use the pid function */
5175 if (tr
->flags
& TRACE_ARRAY_FL_GLOBAL
) {
5176 if (WARN_ON(tr
->ops
->func
!= ftrace_stub
))
5177 printk("ftrace ops had %pS for function\n",
5180 tr
->ops
->func
= func
;
5181 tr
->ops
->private = tr
;
5184 void ftrace_reset_array_ops(struct trace_array
*tr
)
5186 tr
->ops
->func
= ftrace_stub
;
5190 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5191 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
5193 struct ftrace_ops
*op
;
5196 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5201 * Some of the ops may be dynamically allocated,
5202 * they must be freed after a synchronize_sched().
5204 preempt_disable_notrace();
5206 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5208 * Check the following for each ops before calling their func:
5209 * if RCU flag is set, then rcu_is_watching() must be true
5210 * if PER_CPU is set, then ftrace_function_local_disable()
5212 * Otherwise test if the ip matches the ops filter
5214 * If any of the above fails then the op->func() is not executed.
5216 if ((!(op
->flags
& FTRACE_OPS_FL_RCU
) || rcu_is_watching()) &&
5217 (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
5218 !ftrace_function_local_disabled(op
)) &&
5219 ftrace_ops_test(op
, ip
, regs
)) {
5221 if (FTRACE_WARN_ON(!op
->func
)) {
5222 pr_warn("op=%p %pS\n", op
, op
);
5225 op
->func(ip
, parent_ip
, op
, regs
);
5227 } while_for_each_ftrace_op(op
);
5229 preempt_enable_notrace();
5230 trace_clear_recursion(bit
);
5234 * Some archs only support passing ip and parent_ip. Even though
5235 * the list function ignores the op parameter, we do not want any
5236 * C side effects, where a function is called without the caller
5237 * sending a third parameter.
5238 * Archs are to support both the regs and ftrace_ops at the same time.
5239 * If they support ftrace_ops, it is assumed they support regs.
5240 * If call backs want to use regs, they must either check for regs
5241 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
5242 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
5243 * An architecture can pass partial regs with ftrace_ops and still
5244 * set the ARCH_SUPPORTS_FTRACE_OPS.
5246 #if ARCH_SUPPORTS_FTRACE_OPS
5247 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
5248 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5250 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
5253 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
5255 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
5260 * If there's only one function registered but it does not support
5261 * recursion, needs RCU protection and/or requires per cpu handling, then
5262 * this function will be called by the mcount trampoline.
5264 static void ftrace_ops_assist_func(unsigned long ip
, unsigned long parent_ip
,
5265 struct ftrace_ops
*op
, struct pt_regs
*regs
)
5269 if ((op
->flags
& FTRACE_OPS_FL_RCU
) && !rcu_is_watching())
5272 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
5276 preempt_disable_notrace();
5278 if (!(op
->flags
& FTRACE_OPS_FL_PER_CPU
) ||
5279 !ftrace_function_local_disabled(op
)) {
5280 op
->func(ip
, parent_ip
, op
, regs
);
5283 preempt_enable_notrace();
5284 trace_clear_recursion(bit
);
5288 * ftrace_ops_get_func - get the function a trampoline should call
5289 * @ops: the ops to get the function for
5291 * Normally the mcount trampoline will call the ops->func, but there
5292 * are times that it should not. For example, if the ops does not
5293 * have its own recursion protection, then it should call the
5294 * ftrace_ops_recurs_func() instead.
5296 * Returns the function that the trampoline should call for @ops.
5298 ftrace_func_t
ftrace_ops_get_func(struct ftrace_ops
*ops
)
5301 * If the function does not handle recursion, needs to be RCU safe,
5302 * or does per cpu logic, then we need to call the assist handler.
5304 if (!(ops
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) ||
5305 ops
->flags
& (FTRACE_OPS_FL_RCU
| FTRACE_OPS_FL_PER_CPU
))
5306 return ftrace_ops_assist_func
;
5311 static void clear_ftrace_swapper(void)
5313 struct task_struct
*p
;
5317 for_each_online_cpu(cpu
) {
5319 clear_tsk_trace_trace(p
);
5324 static void set_ftrace_swapper(void)
5326 struct task_struct
*p
;
5330 for_each_online_cpu(cpu
) {
5332 set_tsk_trace_trace(p
);
5337 static void clear_ftrace_pid(struct pid
*pid
)
5339 struct task_struct
*p
;
5342 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
5343 clear_tsk_trace_trace(p
);
5344 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
5350 static void set_ftrace_pid(struct pid
*pid
)
5352 struct task_struct
*p
;
5355 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
5356 set_tsk_trace_trace(p
);
5357 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
5361 static void clear_ftrace_pid_task(struct pid
*pid
)
5363 if (pid
== ftrace_swapper_pid
)
5364 clear_ftrace_swapper();
5366 clear_ftrace_pid(pid
);
5369 static void set_ftrace_pid_task(struct pid
*pid
)
5371 if (pid
== ftrace_swapper_pid
)
5372 set_ftrace_swapper();
5374 set_ftrace_pid(pid
);
5377 static int ftrace_pid_add(int p
)
5380 struct ftrace_pid
*fpid
;
5383 mutex_lock(&ftrace_lock
);
5386 pid
= ftrace_swapper_pid
;
5388 pid
= find_get_pid(p
);
5395 list_for_each_entry(fpid
, &ftrace_pids
, list
)
5396 if (fpid
->pid
== pid
)
5401 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
5405 list_add(&fpid
->list
, &ftrace_pids
);
5408 set_ftrace_pid_task(pid
);
5410 ftrace_update_pid_func();
5412 ftrace_startup_all(0);
5414 mutex_unlock(&ftrace_lock
);
5418 if (pid
!= ftrace_swapper_pid
)
5422 mutex_unlock(&ftrace_lock
);
5426 static void ftrace_pid_reset(void)
5428 struct ftrace_pid
*fpid
, *safe
;
5430 mutex_lock(&ftrace_lock
);
5431 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
5432 struct pid
*pid
= fpid
->pid
;
5434 clear_ftrace_pid_task(pid
);
5436 list_del(&fpid
->list
);
5440 ftrace_update_pid_func();
5441 ftrace_startup_all(0);
5443 mutex_unlock(&ftrace_lock
);
5446 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
5448 mutex_lock(&ftrace_lock
);
5450 if (!ftrace_pids_enabled() && (!*pos
))
5453 return seq_list_start(&ftrace_pids
, *pos
);
5456 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
5461 return seq_list_next(v
, &ftrace_pids
, pos
);
5464 static void fpid_stop(struct seq_file
*m
, void *p
)
5466 mutex_unlock(&ftrace_lock
);
5469 static int fpid_show(struct seq_file
*m
, void *v
)
5471 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
5473 if (v
== (void *)1) {
5474 seq_puts(m
, "no pid\n");
5478 if (fpid
->pid
== ftrace_swapper_pid
)
5479 seq_puts(m
, "swapper tasks\n");
5481 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
5486 static const struct seq_operations ftrace_pid_sops
= {
5487 .start
= fpid_start
,
5494 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
5498 if ((file
->f_mode
& FMODE_WRITE
) &&
5499 (file
->f_flags
& O_TRUNC
))
5502 if (file
->f_mode
& FMODE_READ
)
5503 ret
= seq_open(file
, &ftrace_pid_sops
);
5509 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
5510 size_t cnt
, loff_t
*ppos
)
5516 if (cnt
>= sizeof(buf
))
5519 if (copy_from_user(&buf
, ubuf
, cnt
))
5525 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
5526 * to clean the filter quietly.
5528 tmp
= strstrip(buf
);
5529 if (strlen(tmp
) == 0)
5532 ret
= kstrtol(tmp
, 10, &val
);
5536 ret
= ftrace_pid_add(val
);
5538 return ret
? ret
: cnt
;
5542 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
5544 if (file
->f_mode
& FMODE_READ
)
5545 seq_release(inode
, file
);
5550 static const struct file_operations ftrace_pid_fops
= {
5551 .open
= ftrace_pid_open
,
5552 .write
= ftrace_pid_write
,
5554 .llseek
= tracing_lseek
,
5555 .release
= ftrace_pid_release
,
5558 static __init
int ftrace_init_tracefs(void)
5560 struct dentry
*d_tracer
;
5562 d_tracer
= tracing_init_dentry();
5563 if (IS_ERR(d_tracer
))
5566 ftrace_init_dyn_tracefs(d_tracer
);
5568 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
5569 NULL
, &ftrace_pid_fops
);
5571 ftrace_profile_tracefs(d_tracer
);
5575 fs_initcall(ftrace_init_tracefs
);
5578 * ftrace_kill - kill ftrace
5580 * This function should be used by panic code. It stops ftrace
5581 * but in a not so nice way. If you need to simply kill ftrace
5582 * from a non-atomic section, use ftrace_kill.
5584 void ftrace_kill(void)
5586 ftrace_disabled
= 1;
5588 clear_ftrace_function();
5592 * Test if ftrace is dead or not.
5594 int ftrace_is_dead(void)
5596 return ftrace_disabled
;
5600 * register_ftrace_function - register a function for profiling
5601 * @ops - ops structure that holds the function for profiling.
5603 * Register a function to be called by all functions in the
5606 * Note: @ops->func and all the functions it calls must be labeled
5607 * with "notrace", otherwise it will go into a
5610 int register_ftrace_function(struct ftrace_ops
*ops
)
5614 ftrace_ops_init(ops
);
5616 mutex_lock(&ftrace_lock
);
5618 ret
= ftrace_startup(ops
, 0);
5620 mutex_unlock(&ftrace_lock
);
5624 EXPORT_SYMBOL_GPL(register_ftrace_function
);
5627 * unregister_ftrace_function - unregister a function for profiling.
5628 * @ops - ops structure that holds the function to unregister
5630 * Unregister a function that was added to be called by ftrace profiling.
5632 int unregister_ftrace_function(struct ftrace_ops
*ops
)
5636 mutex_lock(&ftrace_lock
);
5637 ret
= ftrace_shutdown(ops
, 0);
5638 mutex_unlock(&ftrace_lock
);
5642 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
5645 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
5646 void __user
*buffer
, size_t *lenp
,
5651 mutex_lock(&ftrace_lock
);
5653 if (unlikely(ftrace_disabled
))
5656 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
5658 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
5661 last_ftrace_enabled
= !!ftrace_enabled
;
5663 if (ftrace_enabled
) {
5665 /* we are starting ftrace again */
5666 if (ftrace_ops_list
!= &ftrace_list_end
)
5667 update_ftrace_function();
5669 ftrace_startup_sysctl();
5672 /* stopping ftrace calls (just send to ftrace_stub) */
5673 ftrace_trace_function
= ftrace_stub
;
5675 ftrace_shutdown_sysctl();
5679 mutex_unlock(&ftrace_lock
);
5683 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5685 static struct ftrace_ops graph_ops
= {
5686 .func
= ftrace_stub
,
5687 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5688 FTRACE_OPS_FL_INITIALIZED
|
5691 #ifdef FTRACE_GRAPH_TRAMP_ADDR
5692 .trampoline
= FTRACE_GRAPH_TRAMP_ADDR
,
5693 /* trampoline_size is only needed for dynamically allocated tramps */
5695 ASSIGN_OPS_HASH(graph_ops
, &global_ops
.local_hash
)
5698 void ftrace_graph_sleep_time_control(bool enable
)
5700 fgraph_sleep_time
= enable
;
5703 void ftrace_graph_graph_time_control(bool enable
)
5705 fgraph_graph_time
= enable
;
5708 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
5713 /* The callbacks that hook a function */
5714 trace_func_graph_ret_t ftrace_graph_return
=
5715 (trace_func_graph_ret_t
)ftrace_stub
;
5716 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
5717 static trace_func_graph_ent_t __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5719 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5720 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
5724 unsigned long flags
;
5725 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
5726 struct task_struct
*g
, *t
;
5728 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
5729 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
5730 * sizeof(struct ftrace_ret_stack
),
5732 if (!ret_stack_list
[i
]) {
5740 read_lock_irqsave(&tasklist_lock
, flags
);
5741 do_each_thread(g
, t
) {
5747 if (t
->ret_stack
== NULL
) {
5748 atomic_set(&t
->tracing_graph_pause
, 0);
5749 atomic_set(&t
->trace_overrun
, 0);
5750 t
->curr_ret_stack
= -1;
5751 /* Make sure the tasks see the -1 first: */
5753 t
->ret_stack
= ret_stack_list
[start
++];
5755 } while_each_thread(g
, t
);
5758 read_unlock_irqrestore(&tasklist_lock
, flags
);
5760 for (i
= start
; i
< end
; i
++)
5761 kfree(ret_stack_list
[i
]);
5766 ftrace_graph_probe_sched_switch(void *ignore
, bool preempt
,
5767 struct task_struct
*prev
, struct task_struct
*next
)
5769 unsigned long long timestamp
;
5773 * Does the user want to count the time a function was asleep.
5774 * If so, do not update the time stamps.
5776 if (fgraph_sleep_time
)
5779 timestamp
= trace_clock_local();
5781 prev
->ftrace_timestamp
= timestamp
;
5783 /* only process tasks that we timestamped */
5784 if (!next
->ftrace_timestamp
)
5788 * Update all the counters in next to make up for the
5789 * time next was sleeping.
5791 timestamp
-= next
->ftrace_timestamp
;
5793 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
5794 next
->ret_stack
[index
].calltime
+= timestamp
;
5797 /* Allocate a return stack for each task */
5798 static int start_graph_tracing(void)
5800 struct ftrace_ret_stack
**ret_stack_list
;
5803 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
5804 sizeof(struct ftrace_ret_stack
*),
5807 if (!ret_stack_list
)
5810 /* The cpu_boot init_task->ret_stack will never be freed */
5811 for_each_online_cpu(cpu
) {
5812 if (!idle_task(cpu
)->ret_stack
)
5813 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
5817 ret
= alloc_retstack_tasklist(ret_stack_list
);
5818 } while (ret
== -EAGAIN
);
5821 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5823 pr_info("ftrace_graph: Couldn't activate tracepoint"
5824 " probe to kernel_sched_switch\n");
5827 kfree(ret_stack_list
);
5832 * Hibernation protection.
5833 * The state of the current task is too much unstable during
5834 * suspend/restore to disk. We want to protect against that.
5837 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
5841 case PM_HIBERNATION_PREPARE
:
5842 pause_graph_tracing();
5845 case PM_POST_HIBERNATION
:
5846 unpause_graph_tracing();
5852 static int ftrace_graph_entry_test(struct ftrace_graph_ent
*trace
)
5854 if (!ftrace_ops_test(&global_ops
, trace
->func
, NULL
))
5856 return __ftrace_graph_entry(trace
);
5860 * The function graph tracer should only trace the functions defined
5861 * by set_ftrace_filter and set_ftrace_notrace. If another function
5862 * tracer ops is registered, the graph tracer requires testing the
5863 * function against the global ops, and not just trace any function
5864 * that any ftrace_ops registered.
5866 static void update_function_graph_func(void)
5868 struct ftrace_ops
*op
;
5869 bool do_test
= false;
5872 * The graph and global ops share the same set of functions
5873 * to test. If any other ops is on the list, then
5874 * the graph tracing needs to test if its the function
5877 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5878 if (op
!= &global_ops
&& op
!= &graph_ops
&&
5879 op
!= &ftrace_list_end
) {
5881 /* in double loop, break out with goto */
5884 } while_for_each_ftrace_op(op
);
5887 ftrace_graph_entry
= ftrace_graph_entry_test
;
5889 ftrace_graph_entry
= __ftrace_graph_entry
;
5892 static struct notifier_block ftrace_suspend_notifier
= {
5893 .notifier_call
= ftrace_suspend_notifier_call
,
5896 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
5897 trace_func_graph_ent_t entryfunc
)
5901 mutex_lock(&ftrace_lock
);
5903 /* we currently allow only one tracer registered at a time */
5904 if (ftrace_graph_active
) {
5909 register_pm_notifier(&ftrace_suspend_notifier
);
5911 ftrace_graph_active
++;
5912 ret
= start_graph_tracing();
5914 ftrace_graph_active
--;
5918 ftrace_graph_return
= retfunc
;
5921 * Update the indirect function to the entryfunc, and the
5922 * function that gets called to the entry_test first. Then
5923 * call the update fgraph entry function to determine if
5924 * the entryfunc should be called directly or not.
5926 __ftrace_graph_entry
= entryfunc
;
5927 ftrace_graph_entry
= ftrace_graph_entry_test
;
5928 update_function_graph_func();
5930 ret
= ftrace_startup(&graph_ops
, FTRACE_START_FUNC_RET
);
5932 mutex_unlock(&ftrace_lock
);
5936 void unregister_ftrace_graph(void)
5938 mutex_lock(&ftrace_lock
);
5940 if (unlikely(!ftrace_graph_active
))
5943 ftrace_graph_active
--;
5944 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
5945 ftrace_graph_entry
= ftrace_graph_entry_stub
;
5946 __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5947 ftrace_shutdown(&graph_ops
, FTRACE_STOP_FUNC_RET
);
5948 unregister_pm_notifier(&ftrace_suspend_notifier
);
5949 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5951 #ifdef CONFIG_DYNAMIC_FTRACE
5953 * Function graph does not allocate the trampoline, but
5954 * other global_ops do. We need to reset the ALLOC_TRAMP flag
5957 global_ops
.trampoline
= save_global_trampoline
;
5958 if (save_global_flags
& FTRACE_OPS_FL_ALLOC_TRAMP
)
5959 global_ops
.flags
|= FTRACE_OPS_FL_ALLOC_TRAMP
;
5963 mutex_unlock(&ftrace_lock
);
5966 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
5969 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
5971 atomic_set(&t
->tracing_graph_pause
, 0);
5972 atomic_set(&t
->trace_overrun
, 0);
5973 t
->ftrace_timestamp
= 0;
5974 /* make curr_ret_stack visible before we add the ret_stack */
5976 t
->ret_stack
= ret_stack
;
5980 * Allocate a return stack for the idle task. May be the first
5981 * time through, or it may be done by CPU hotplug online.
5983 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
5985 t
->curr_ret_stack
= -1;
5987 * The idle task has no parent, it either has its own
5988 * stack or no stack at all.
5991 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
5993 if (ftrace_graph_active
) {
5994 struct ftrace_ret_stack
*ret_stack
;
5996 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
5998 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5999 * sizeof(struct ftrace_ret_stack
),
6003 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
6005 graph_init_task(t
, ret_stack
);
6009 /* Allocate a return stack for newly created task */
6010 void ftrace_graph_init_task(struct task_struct
*t
)
6012 /* Make sure we do not use the parent ret_stack */
6013 t
->ret_stack
= NULL
;
6014 t
->curr_ret_stack
= -1;
6016 if (ftrace_graph_active
) {
6017 struct ftrace_ret_stack
*ret_stack
;
6019 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
6020 * sizeof(struct ftrace_ret_stack
),
6024 graph_init_task(t
, ret_stack
);
6028 void ftrace_graph_exit_task(struct task_struct
*t
)
6030 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
6032 t
->ret_stack
= NULL
;
6033 /* NULL must become visible to IRQs before we free it: */