1 // SPDX-License-Identifier: GPL-2.0
3 * Infrastructure for profiling code inserted by 'gcc -pg'.
5 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
6 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
8 * Originally ported from the -rt patch by:
9 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
11 * Based on code in the latency_tracer, that is:
13 * Copyright (C) 2004-2006 Ingo Molnar
14 * Copyright (C) 2004 Nadia Yvette Chambers
17 #include <linux/stop_machine.h>
18 #include <linux/clocksource.h>
19 #include <linux/sched/task.h>
20 #include <linux/kallsyms.h>
21 #include <linux/seq_file.h>
22 #include <linux/tracefs.h>
23 #include <linux/hardirq.h>
24 #include <linux/kthread.h>
25 #include <linux/uaccess.h>
26 #include <linux/bsearch.h>
27 #include <linux/module.h>
28 #include <linux/ftrace.h>
29 #include <linux/sysctl.h>
30 #include <linux/slab.h>
31 #include <linux/ctype.h>
32 #include <linux/sort.h>
33 #include <linux/list.h>
34 #include <linux/hash.h>
35 #include <linux/rcupdate.h>
36 #include <linux/kprobes.h>
38 #include <trace/events/sched.h>
40 #include <asm/sections.h>
41 #include <asm/setup.h>
43 #include "ftrace_internal.h"
44 #include "trace_output.h"
45 #include "trace_stat.h"
47 #define FTRACE_WARN_ON(cond) \
55 #define FTRACE_WARN_ON_ONCE(cond) \
58 if (WARN_ON_ONCE(___r)) \
63 /* hash bits for specific function selection */
64 #define FTRACE_HASH_BITS 7
65 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
66 #define FTRACE_HASH_DEFAULT_BITS 10
67 #define FTRACE_HASH_MAX_BITS 12
69 #ifdef CONFIG_DYNAMIC_FTRACE
70 #define INIT_OPS_HASH(opsname) \
71 .func_hash = &opsname.local_hash, \
72 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
74 #define INIT_OPS_HASH(opsname)
78 FTRACE_MODIFY_ENABLE_FL
= (1 << 0),
79 FTRACE_MODIFY_MAY_SLEEP_FL
= (1 << 1),
82 struct ftrace_ops ftrace_list_end __read_mostly
= {
84 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_STUB
,
85 INIT_OPS_HASH(ftrace_list_end
)
88 /* ftrace_enabled is a method to turn ftrace on or off */
89 int ftrace_enabled __read_mostly
;
90 static int last_ftrace_enabled
;
92 /* Current function tracing op */
93 struct ftrace_ops
*function_trace_op __read_mostly
= &ftrace_list_end
;
94 /* What to set function_trace_op to */
95 static struct ftrace_ops
*set_function_trace_op
;
97 static bool ftrace_pids_enabled(struct ftrace_ops
*ops
)
99 struct trace_array
*tr
;
101 if (!(ops
->flags
& FTRACE_OPS_FL_PID
) || !ops
->private)
106 return tr
->function_pids
!= NULL
;
109 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
112 * ftrace_disabled is set when an anomaly is discovered.
113 * ftrace_disabled is much stronger than ftrace_enabled.
115 static int ftrace_disabled __read_mostly
;
117 DEFINE_MUTEX(ftrace_lock
);
119 struct ftrace_ops __rcu
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
120 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
121 struct ftrace_ops global_ops
;
123 #if ARCH_SUPPORTS_FTRACE_OPS
124 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
125 struct ftrace_ops
*op
, struct pt_regs
*regs
);
127 /* See comment below, where ftrace_ops_list_func is defined */
128 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
129 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
132 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
134 #ifdef CONFIG_DYNAMIC_FTRACE
135 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
136 mutex_init(&ops
->local_hash
.regex_lock
);
137 ops
->func_hash
= &ops
->local_hash
;
138 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
143 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
144 struct ftrace_ops
*op
, struct pt_regs
*regs
)
146 struct trace_array
*tr
= op
->private;
148 if (tr
&& this_cpu_read(tr
->trace_buffer
.data
->ftrace_ignore_pid
))
151 op
->saved_func(ip
, parent_ip
, op
, regs
);
154 static void ftrace_sync(struct work_struct
*work
)
157 * This function is just a stub to implement a hard force
158 * of synchronize_rcu(). This requires synchronizing
159 * tasks even in userspace and idle.
161 * Yes, function tracing is rude.
165 static void ftrace_sync_ipi(void *data
)
167 /* Probably not needed, but do it anyway */
171 static ftrace_func_t
ftrace_ops_get_list_func(struct ftrace_ops
*ops
)
174 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
175 * then it needs to call the list anyway.
177 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_RCU
) ||
178 FTRACE_FORCE_LIST_FUNC
)
179 return ftrace_ops_list_func
;
181 return ftrace_ops_get_func(ops
);
184 static void update_ftrace_function(void)
189 * Prepare the ftrace_ops that the arch callback will use.
190 * If there's only one ftrace_ops registered, the ftrace_ops_list
191 * will point to the ops we want.
193 set_function_trace_op
= rcu_dereference_protected(ftrace_ops_list
,
194 lockdep_is_held(&ftrace_lock
));
196 /* If there's no ftrace_ops registered, just call the stub function */
197 if (set_function_trace_op
== &ftrace_list_end
) {
201 * If we are at the end of the list and this ops is
202 * recursion safe and not dynamic and the arch supports passing ops,
203 * then have the mcount trampoline call the function directly.
205 } else if (rcu_dereference_protected(ftrace_ops_list
->next
,
206 lockdep_is_held(&ftrace_lock
)) == &ftrace_list_end
) {
207 func
= ftrace_ops_get_list_func(ftrace_ops_list
);
210 /* Just use the default ftrace_ops */
211 set_function_trace_op
= &ftrace_list_end
;
212 func
= ftrace_ops_list_func
;
215 update_function_graph_func();
217 /* If there's no change, then do nothing more here */
218 if (ftrace_trace_function
== func
)
222 * If we are using the list function, it doesn't care
223 * about the function_trace_ops.
225 if (func
== ftrace_ops_list_func
) {
226 ftrace_trace_function
= func
;
228 * Don't even bother setting function_trace_ops,
229 * it would be racy to do so anyway.
234 #ifndef CONFIG_DYNAMIC_FTRACE
236 * For static tracing, we need to be a bit more careful.
237 * The function change takes affect immediately. Thus,
238 * we need to coorditate the setting of the function_trace_ops
239 * with the setting of the ftrace_trace_function.
241 * Set the function to the list ops, which will call the
242 * function we want, albeit indirectly, but it handles the
243 * ftrace_ops and doesn't depend on function_trace_op.
245 ftrace_trace_function
= ftrace_ops_list_func
;
247 * Make sure all CPUs see this. Yes this is slow, but static
248 * tracing is slow and nasty to have enabled.
250 schedule_on_each_cpu(ftrace_sync
);
251 /* Now all cpus are using the list ops. */
252 function_trace_op
= set_function_trace_op
;
253 /* Make sure the function_trace_op is visible on all CPUs */
255 /* Nasty way to force a rmb on all cpus */
256 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
257 /* OK, we are all set to update the ftrace_trace_function now! */
258 #endif /* !CONFIG_DYNAMIC_FTRACE */
260 ftrace_trace_function
= func
;
263 static void add_ftrace_ops(struct ftrace_ops __rcu
**list
,
264 struct ftrace_ops
*ops
)
266 rcu_assign_pointer(ops
->next
, *list
);
269 * We are entering ops into the list but another
270 * CPU might be walking that list. We need to make sure
271 * the ops->next pointer is valid before another CPU sees
272 * the ops pointer included into the list.
274 rcu_assign_pointer(*list
, ops
);
277 static int remove_ftrace_ops(struct ftrace_ops __rcu
**list
,
278 struct ftrace_ops
*ops
)
280 struct ftrace_ops
**p
;
283 * If we are removing the last function, then simply point
284 * to the ftrace_stub.
286 if (rcu_dereference_protected(*list
,
287 lockdep_is_held(&ftrace_lock
)) == ops
&&
288 rcu_dereference_protected(ops
->next
,
289 lockdep_is_held(&ftrace_lock
)) == &ftrace_list_end
) {
290 *list
= &ftrace_list_end
;
294 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
305 static void ftrace_update_trampoline(struct ftrace_ops
*ops
);
307 int __register_ftrace_function(struct ftrace_ops
*ops
)
309 if (ops
->flags
& FTRACE_OPS_FL_DELETED
)
312 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
315 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
317 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
318 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
319 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
321 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
322 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
325 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
326 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
329 if (!core_kernel_data((unsigned long)ops
))
330 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
332 add_ftrace_ops(&ftrace_ops_list
, ops
);
334 /* Always save the function, and reset at unregistering */
335 ops
->saved_func
= ops
->func
;
337 if (ftrace_pids_enabled(ops
))
338 ops
->func
= ftrace_pid_func
;
340 ftrace_update_trampoline(ops
);
343 update_ftrace_function();
348 int __unregister_ftrace_function(struct ftrace_ops
*ops
)
352 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
355 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
361 update_ftrace_function();
363 ops
->func
= ops
->saved_func
;
368 static void ftrace_update_pid_func(void)
370 struct ftrace_ops
*op
;
372 /* Only do something if we are tracing something */
373 if (ftrace_trace_function
== ftrace_stub
)
376 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
377 if (op
->flags
& FTRACE_OPS_FL_PID
) {
378 op
->func
= ftrace_pids_enabled(op
) ?
379 ftrace_pid_func
: op
->saved_func
;
380 ftrace_update_trampoline(op
);
382 } while_for_each_ftrace_op(op
);
384 update_ftrace_function();
387 #ifdef CONFIG_FUNCTION_PROFILER
388 struct ftrace_profile
{
389 struct hlist_node node
;
391 unsigned long counter
;
392 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
393 unsigned long long time
;
394 unsigned long long time_squared
;
398 struct ftrace_profile_page
{
399 struct ftrace_profile_page
*next
;
401 struct ftrace_profile records
[];
404 struct ftrace_profile_stat
{
406 struct hlist_head
*hash
;
407 struct ftrace_profile_page
*pages
;
408 struct ftrace_profile_page
*start
;
409 struct tracer_stat stat
;
412 #define PROFILE_RECORDS_SIZE \
413 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
415 #define PROFILES_PER_PAGE \
416 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
418 static int ftrace_profile_enabled __read_mostly
;
420 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
421 static DEFINE_MUTEX(ftrace_profile_lock
);
423 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
425 #define FTRACE_PROFILE_HASH_BITS 10
426 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
429 function_stat_next(void *v
, int idx
)
431 struct ftrace_profile
*rec
= v
;
432 struct ftrace_profile_page
*pg
;
434 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
440 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
444 rec
= &pg
->records
[0];
452 static void *function_stat_start(struct tracer_stat
*trace
)
454 struct ftrace_profile_stat
*stat
=
455 container_of(trace
, struct ftrace_profile_stat
, stat
);
457 if (!stat
|| !stat
->start
)
460 return function_stat_next(&stat
->start
->records
[0], 0);
463 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
464 /* function graph compares on total time */
465 static int function_stat_cmp(void *p1
, void *p2
)
467 struct ftrace_profile
*a
= p1
;
468 struct ftrace_profile
*b
= p2
;
470 if (a
->time
< b
->time
)
472 if (a
->time
> b
->time
)
478 /* not function graph compares against hits */
479 static int function_stat_cmp(void *p1
, void *p2
)
481 struct ftrace_profile
*a
= p1
;
482 struct ftrace_profile
*b
= p2
;
484 if (a
->counter
< b
->counter
)
486 if (a
->counter
> b
->counter
)
493 static int function_stat_headers(struct seq_file
*m
)
495 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
496 seq_puts(m
, " Function "
499 "--- ---- --- ---\n");
501 seq_puts(m
, " Function Hit\n"
507 static int function_stat_show(struct seq_file
*m
, void *v
)
509 struct ftrace_profile
*rec
= v
;
510 char str
[KSYM_SYMBOL_LEN
];
512 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
513 static struct trace_seq s
;
514 unsigned long long avg
;
515 unsigned long long stddev
;
517 mutex_lock(&ftrace_profile_lock
);
519 /* we raced with function_profile_reset() */
520 if (unlikely(rec
->counter
== 0)) {
525 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
527 do_div(avg
, rec
->counter
);
528 if (tracing_thresh
&& (avg
< tracing_thresh
))
532 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
533 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
535 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
538 /* Sample standard deviation (s^2) */
539 if (rec
->counter
<= 1)
543 * Apply Welford's method:
544 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
546 stddev
= rec
->counter
* rec
->time_squared
-
547 rec
->time
* rec
->time
;
550 * Divide only 1000 for ns^2 -> us^2 conversion.
551 * trace_print_graph_duration will divide 1000 again.
553 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
557 trace_print_graph_duration(rec
->time
, &s
);
558 trace_seq_puts(&s
, " ");
559 trace_print_graph_duration(avg
, &s
);
560 trace_seq_puts(&s
, " ");
561 trace_print_graph_duration(stddev
, &s
);
562 trace_print_seq(m
, &s
);
566 mutex_unlock(&ftrace_profile_lock
);
571 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
573 struct ftrace_profile_page
*pg
;
575 pg
= stat
->pages
= stat
->start
;
578 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
583 memset(stat
->hash
, 0,
584 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
587 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
589 struct ftrace_profile_page
*pg
;
594 /* If we already allocated, do nothing */
598 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
602 #ifdef CONFIG_DYNAMIC_FTRACE
603 functions
= ftrace_update_tot_cnt
;
606 * We do not know the number of functions that exist because
607 * dynamic tracing is what counts them. With past experience
608 * we have around 20K functions. That should be more than enough.
609 * It is highly unlikely we will execute every function in
615 pg
= stat
->start
= stat
->pages
;
617 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
619 for (i
= 1; i
< pages
; i
++) {
620 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
631 unsigned long tmp
= (unsigned long)pg
;
643 static int ftrace_profile_init_cpu(int cpu
)
645 struct ftrace_profile_stat
*stat
;
648 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
651 /* If the profile is already created, simply reset it */
652 ftrace_profile_reset(stat
);
657 * We are profiling all functions, but usually only a few thousand
658 * functions are hit. We'll make a hash of 1024 items.
660 size
= FTRACE_PROFILE_HASH_SIZE
;
662 stat
->hash
= kcalloc(size
, sizeof(struct hlist_head
), GFP_KERNEL
);
667 /* Preallocate the function profiling pages */
668 if (ftrace_profile_pages_init(stat
) < 0) {
677 static int ftrace_profile_init(void)
682 for_each_possible_cpu(cpu
) {
683 ret
= ftrace_profile_init_cpu(cpu
);
691 /* interrupts must be disabled */
692 static struct ftrace_profile
*
693 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
695 struct ftrace_profile
*rec
;
696 struct hlist_head
*hhd
;
699 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
700 hhd
= &stat
->hash
[key
];
702 if (hlist_empty(hhd
))
705 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
713 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
714 struct ftrace_profile
*rec
)
718 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
719 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
723 * The memory is already allocated, this simply finds a new record to use.
725 static struct ftrace_profile
*
726 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
728 struct ftrace_profile
*rec
= NULL
;
730 /* prevent recursion (from NMIs) */
731 if (atomic_inc_return(&stat
->disabled
) != 1)
735 * Try to find the function again since an NMI
736 * could have added it
738 rec
= ftrace_find_profiled_func(stat
, ip
);
742 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
743 if (!stat
->pages
->next
)
745 stat
->pages
= stat
->pages
->next
;
748 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
750 ftrace_add_profile(stat
, rec
);
753 atomic_dec(&stat
->disabled
);
759 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
760 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
762 struct ftrace_profile_stat
*stat
;
763 struct ftrace_profile
*rec
;
766 if (!ftrace_profile_enabled
)
769 local_irq_save(flags
);
771 stat
= this_cpu_ptr(&ftrace_profile_stats
);
772 if (!stat
->hash
|| !ftrace_profile_enabled
)
775 rec
= ftrace_find_profiled_func(stat
, ip
);
777 rec
= ftrace_profile_alloc(stat
, ip
);
784 local_irq_restore(flags
);
787 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
788 static bool fgraph_graph_time
= true;
790 void ftrace_graph_graph_time_control(bool enable
)
792 fgraph_graph_time
= enable
;
795 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
797 struct ftrace_ret_stack
*ret_stack
;
799 function_profile_call(trace
->func
, 0, NULL
, NULL
);
801 /* If function graph is shutting down, ret_stack can be NULL */
802 if (!current
->ret_stack
)
805 ret_stack
= ftrace_graph_get_ret_stack(current
, 0);
807 ret_stack
->subtime
= 0;
812 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
814 struct ftrace_ret_stack
*ret_stack
;
815 struct ftrace_profile_stat
*stat
;
816 unsigned long long calltime
;
817 struct ftrace_profile
*rec
;
820 local_irq_save(flags
);
821 stat
= this_cpu_ptr(&ftrace_profile_stats
);
822 if (!stat
->hash
|| !ftrace_profile_enabled
)
825 /* If the calltime was zero'd ignore it */
826 if (!trace
->calltime
)
829 calltime
= trace
->rettime
- trace
->calltime
;
831 if (!fgraph_graph_time
) {
833 /* Append this call time to the parent time to subtract */
834 ret_stack
= ftrace_graph_get_ret_stack(current
, 1);
836 ret_stack
->subtime
+= calltime
;
838 ret_stack
= ftrace_graph_get_ret_stack(current
, 0);
839 if (ret_stack
&& ret_stack
->subtime
< calltime
)
840 calltime
-= ret_stack
->subtime
;
845 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
847 rec
->time
+= calltime
;
848 rec
->time_squared
+= calltime
* calltime
;
852 local_irq_restore(flags
);
855 static struct fgraph_ops fprofiler_ops
= {
856 .entryfunc
= &profile_graph_entry
,
857 .retfunc
= &profile_graph_return
,
860 static int register_ftrace_profiler(void)
862 return register_ftrace_graph(&fprofiler_ops
);
865 static void unregister_ftrace_profiler(void)
867 unregister_ftrace_graph(&fprofiler_ops
);
870 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
871 .func
= function_profile_call
,
872 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
873 INIT_OPS_HASH(ftrace_profile_ops
)
876 static int register_ftrace_profiler(void)
878 return register_ftrace_function(&ftrace_profile_ops
);
881 static void unregister_ftrace_profiler(void)
883 unregister_ftrace_function(&ftrace_profile_ops
);
885 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
888 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
889 size_t cnt
, loff_t
*ppos
)
894 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
900 mutex_lock(&ftrace_profile_lock
);
901 if (ftrace_profile_enabled
^ val
) {
903 ret
= ftrace_profile_init();
909 ret
= register_ftrace_profiler();
914 ftrace_profile_enabled
= 1;
916 ftrace_profile_enabled
= 0;
918 * unregister_ftrace_profiler calls stop_machine
919 * so this acts like an synchronize_rcu.
921 unregister_ftrace_profiler();
925 mutex_unlock(&ftrace_profile_lock
);
933 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
934 size_t cnt
, loff_t
*ppos
)
936 char buf
[64]; /* big enough to hold a number */
939 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
940 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
943 static const struct file_operations ftrace_profile_fops
= {
944 .open
= tracing_open_generic
,
945 .read
= ftrace_profile_read
,
946 .write
= ftrace_profile_write
,
947 .llseek
= default_llseek
,
950 /* used to initialize the real stat files */
951 static struct tracer_stat function_stats __initdata
= {
953 .stat_start
= function_stat_start
,
954 .stat_next
= function_stat_next
,
955 .stat_cmp
= function_stat_cmp
,
956 .stat_headers
= function_stat_headers
,
957 .stat_show
= function_stat_show
960 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
962 struct ftrace_profile_stat
*stat
;
963 struct dentry
*entry
;
968 for_each_possible_cpu(cpu
) {
969 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
971 name
= kasprintf(GFP_KERNEL
, "function%d", cpu
);
974 * The files created are permanent, if something happens
975 * we still do not free memory.
978 "Could not allocate stat file for cpu %d\n",
982 stat
->stat
= function_stats
;
983 stat
->stat
.name
= name
;
984 ret
= register_stat_tracer(&stat
->stat
);
987 "Could not register function stat for cpu %d\n",
994 entry
= tracefs_create_file("function_profile_enabled", 0644,
995 d_tracer
, NULL
, &ftrace_profile_fops
);
997 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1000 #else /* CONFIG_FUNCTION_PROFILER */
1001 static __init
void ftrace_profile_tracefs(struct dentry
*d_tracer
)
1004 #endif /* CONFIG_FUNCTION_PROFILER */
1006 #ifdef CONFIG_DYNAMIC_FTRACE
1008 static struct ftrace_ops
*removed_ops
;
1011 * Set when doing a global update, like enabling all recs or disabling them.
1012 * It is not set when just updating a single ftrace_ops.
1014 static bool update_all_ops
;
1016 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1017 # error Dynamic ftrace depends on MCOUNT_RECORD
1020 struct ftrace_func_entry
{
1021 struct hlist_node hlist
;
1025 struct ftrace_func_probe
{
1026 struct ftrace_probe_ops
*probe_ops
;
1027 struct ftrace_ops ops
;
1028 struct trace_array
*tr
;
1029 struct list_head list
;
1035 * We make these constant because no one should touch them,
1036 * but they are used as the default "empty hash", to avoid allocating
1037 * it all the time. These are in a read only section such that if
1038 * anyone does try to modify it, it will cause an exception.
1040 static const struct hlist_head empty_buckets
[1];
1041 static const struct ftrace_hash empty_hash
= {
1042 .buckets
= (struct hlist_head
*)empty_buckets
,
1044 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1046 struct ftrace_ops global_ops
= {
1047 .func
= ftrace_stub
,
1048 .local_hash
.notrace_hash
= EMPTY_HASH
,
1049 .local_hash
.filter_hash
= EMPTY_HASH
,
1050 INIT_OPS_HASH(global_ops
)
1051 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
1052 FTRACE_OPS_FL_INITIALIZED
|
1057 * Used by the stack undwinder to know about dynamic ftrace trampolines.
1059 struct ftrace_ops
*ftrace_ops_trampoline(unsigned long addr
)
1061 struct ftrace_ops
*op
= NULL
;
1064 * Some of the ops may be dynamically allocated,
1065 * they are freed after a synchronize_rcu().
1067 preempt_disable_notrace();
1069 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1071 * This is to check for dynamically allocated trampolines.
1072 * Trampolines that are in kernel text will have
1073 * core_kernel_text() return true.
1075 if (op
->trampoline
&& op
->trampoline_size
)
1076 if (addr
>= op
->trampoline
&&
1077 addr
< op
->trampoline
+ op
->trampoline_size
) {
1078 preempt_enable_notrace();
1081 } while_for_each_ftrace_op(op
);
1082 preempt_enable_notrace();
1088 * This is used by __kernel_text_address() to return true if the
1089 * address is on a dynamically allocated trampoline that would
1090 * not return true for either core_kernel_text() or
1091 * is_module_text_address().
1093 bool is_ftrace_trampoline(unsigned long addr
)
1095 return ftrace_ops_trampoline(addr
) != NULL
;
1098 struct ftrace_page
{
1099 struct ftrace_page
*next
;
1100 struct dyn_ftrace
*records
;
1105 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1106 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1108 /* estimate from running different kernels */
1109 #define NR_TO_INIT 10000
1111 static struct ftrace_page
*ftrace_pages_start
;
1112 static struct ftrace_page
*ftrace_pages
;
1114 static __always_inline
unsigned long
1115 ftrace_hash_key(struct ftrace_hash
*hash
, unsigned long ip
)
1117 if (hash
->size_bits
> 0)
1118 return hash_long(ip
, hash
->size_bits
);
1123 /* Only use this function if ftrace_hash_empty() has already been tested */
1124 static __always_inline
struct ftrace_func_entry
*
1125 __ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1128 struct ftrace_func_entry
*entry
;
1129 struct hlist_head
*hhd
;
1131 key
= ftrace_hash_key(hash
, ip
);
1132 hhd
= &hash
->buckets
[key
];
1134 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1135 if (entry
->ip
== ip
)
1142 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1143 * @hash: The hash to look at
1144 * @ip: The instruction pointer to test
1146 * Search a given @hash to see if a given instruction pointer (@ip)
1149 * Returns the entry that holds the @ip if found. NULL otherwise.
1151 struct ftrace_func_entry
*
1152 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1154 if (ftrace_hash_empty(hash
))
1157 return __ftrace_lookup_ip(hash
, ip
);
1160 static void __add_hash_entry(struct ftrace_hash
*hash
,
1161 struct ftrace_func_entry
*entry
)
1163 struct hlist_head
*hhd
;
1166 key
= ftrace_hash_key(hash
, entry
->ip
);
1167 hhd
= &hash
->buckets
[key
];
1168 hlist_add_head(&entry
->hlist
, hhd
);
1172 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1174 struct ftrace_func_entry
*entry
;
1176 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1181 __add_hash_entry(hash
, entry
);
1187 free_hash_entry(struct ftrace_hash
*hash
,
1188 struct ftrace_func_entry
*entry
)
1190 hlist_del(&entry
->hlist
);
1196 remove_hash_entry(struct ftrace_hash
*hash
,
1197 struct ftrace_func_entry
*entry
)
1199 hlist_del_rcu(&entry
->hlist
);
1203 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1205 struct hlist_head
*hhd
;
1206 struct hlist_node
*tn
;
1207 struct ftrace_func_entry
*entry
;
1208 int size
= 1 << hash
->size_bits
;
1214 for (i
= 0; i
< size
; i
++) {
1215 hhd
= &hash
->buckets
[i
];
1216 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1217 free_hash_entry(hash
, entry
);
1219 FTRACE_WARN_ON(hash
->count
);
1222 static void free_ftrace_mod(struct ftrace_mod_load
*ftrace_mod
)
1224 list_del(&ftrace_mod
->list
);
1225 kfree(ftrace_mod
->module
);
1226 kfree(ftrace_mod
->func
);
1230 static void clear_ftrace_mod_list(struct list_head
*head
)
1232 struct ftrace_mod_load
*p
, *n
;
1234 /* stack tracer isn't supported yet */
1238 mutex_lock(&ftrace_lock
);
1239 list_for_each_entry_safe(p
, n
, head
, list
)
1241 mutex_unlock(&ftrace_lock
);
1244 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1246 if (!hash
|| hash
== EMPTY_HASH
)
1248 ftrace_hash_clear(hash
);
1249 kfree(hash
->buckets
);
1253 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1255 struct ftrace_hash
*hash
;
1257 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1258 free_ftrace_hash(hash
);
1261 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1263 if (!hash
|| hash
== EMPTY_HASH
)
1265 call_rcu(&hash
->rcu
, __free_ftrace_hash_rcu
);
1268 void ftrace_free_filter(struct ftrace_ops
*ops
)
1270 ftrace_ops_init(ops
);
1271 free_ftrace_hash(ops
->func_hash
->filter_hash
);
1272 free_ftrace_hash(ops
->func_hash
->notrace_hash
);
1275 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1277 struct ftrace_hash
*hash
;
1280 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1284 size
= 1 << size_bits
;
1285 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1287 if (!hash
->buckets
) {
1292 hash
->size_bits
= size_bits
;
1298 static int ftrace_add_mod(struct trace_array
*tr
,
1299 const char *func
, const char *module
,
1302 struct ftrace_mod_load
*ftrace_mod
;
1303 struct list_head
*mod_head
= enable
? &tr
->mod_trace
: &tr
->mod_notrace
;
1305 ftrace_mod
= kzalloc(sizeof(*ftrace_mod
), GFP_KERNEL
);
1309 ftrace_mod
->func
= kstrdup(func
, GFP_KERNEL
);
1310 ftrace_mod
->module
= kstrdup(module
, GFP_KERNEL
);
1311 ftrace_mod
->enable
= enable
;
1313 if (!ftrace_mod
->func
|| !ftrace_mod
->module
)
1316 list_add(&ftrace_mod
->list
, mod_head
);
1321 free_ftrace_mod(ftrace_mod
);
1326 static struct ftrace_hash
*
1327 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1329 struct ftrace_func_entry
*entry
;
1330 struct ftrace_hash
*new_hash
;
1335 new_hash
= alloc_ftrace_hash(size_bits
);
1340 new_hash
->flags
= hash
->flags
;
1343 if (ftrace_hash_empty(hash
))
1346 size
= 1 << hash
->size_bits
;
1347 for (i
= 0; i
< size
; i
++) {
1348 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1349 ret
= add_hash_entry(new_hash
, entry
->ip
);
1355 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1360 free_ftrace_hash(new_hash
);
1365 ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1367 ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1369 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1370 struct ftrace_hash
*new_hash
);
1372 static struct ftrace_hash
*
1373 __ftrace_hash_move(struct ftrace_hash
*src
)
1375 struct ftrace_func_entry
*entry
;
1376 struct hlist_node
*tn
;
1377 struct hlist_head
*hhd
;
1378 struct ftrace_hash
*new_hash
;
1379 int size
= src
->count
;
1384 * If the new source is empty, just return the empty_hash.
1386 if (ftrace_hash_empty(src
))
1390 * Make the hash size about 1/2 the # found
1392 for (size
/= 2; size
; size
>>= 1)
1395 /* Don't allocate too much */
1396 if (bits
> FTRACE_HASH_MAX_BITS
)
1397 bits
= FTRACE_HASH_MAX_BITS
;
1399 new_hash
= alloc_ftrace_hash(bits
);
1403 new_hash
->flags
= src
->flags
;
1405 size
= 1 << src
->size_bits
;
1406 for (i
= 0; i
< size
; i
++) {
1407 hhd
= &src
->buckets
[i
];
1408 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1409 remove_hash_entry(src
, entry
);
1410 __add_hash_entry(new_hash
, entry
);
1418 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1419 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1421 struct ftrace_hash
*new_hash
;
1424 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1425 if (ops
->flags
& FTRACE_OPS_FL_IPMODIFY
&& !enable
)
1428 new_hash
= __ftrace_hash_move(src
);
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().
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 rcu_assign_pointer(hash
.filter_hash
, ops
->func_hash
->filter_hash
);
1499 rcu_assign_pointer(hash
.notrace_hash
, 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 bool __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
;
1633 bool update
= false;
1637 /* Only update if the ops has been registered */
1638 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1642 * In the filter_hash case:
1643 * If the count is zero, we update all records.
1644 * Otherwise we just update the items in the hash.
1646 * In the notrace_hash case:
1647 * We enable the update in the hash.
1648 * As disabling notrace means enabling the tracing,
1649 * and enabling notrace means disabling, the inc variable
1653 hash
= ops
->func_hash
->filter_hash
;
1654 other_hash
= ops
->func_hash
->notrace_hash
;
1655 if (ftrace_hash_empty(hash
))
1659 hash
= ops
->func_hash
->notrace_hash
;
1660 other_hash
= ops
->func_hash
->filter_hash
;
1662 * If the notrace hash has no items,
1663 * then there's nothing to do.
1665 if (ftrace_hash_empty(hash
))
1669 do_for_each_ftrace_rec(pg
, rec
) {
1670 int in_other_hash
= 0;
1674 if (rec
->flags
& FTRACE_FL_DISABLED
)
1679 * Only the filter_hash affects all records.
1680 * Update if the record is not in the notrace hash.
1682 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1685 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1686 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1689 * If filter_hash is set, we want to match all functions
1690 * that are in the hash but not in the other hash.
1692 * If filter_hash is not set, then we are decrementing.
1693 * That means we match anything that is in the hash
1694 * and also in the other_hash. That is, we need to turn
1695 * off functions in the other hash because they are disabled
1698 if (filter_hash
&& in_hash
&& !in_other_hash
)
1700 else if (!filter_hash
&& in_hash
&&
1701 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1709 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == FTRACE_REF_MAX
))
1713 * If there's only a single callback registered to a
1714 * function, and the ops has a trampoline registered
1715 * for it, then we can call it directly.
1717 if (ftrace_rec_count(rec
) == 1 && ops
->trampoline
)
1718 rec
->flags
|= FTRACE_FL_TRAMP
;
1721 * If we are adding another function callback
1722 * to this function, and the previous had a
1723 * custom trampoline in use, then we need to go
1724 * back to the default trampoline.
1726 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1729 * If any ops wants regs saved for this function
1730 * then all ops will get saved regs.
1732 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1733 rec
->flags
|= FTRACE_FL_REGS
;
1735 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == 0))
1740 * If the rec had REGS enabled and the ops that is
1741 * being removed had REGS set, then see if there is
1742 * still any ops for this record that wants regs.
1743 * If not, we can stop recording them.
1745 if (ftrace_rec_count(rec
) > 0 &&
1746 rec
->flags
& FTRACE_FL_REGS
&&
1747 ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1748 if (!test_rec_ops_needs_regs(rec
))
1749 rec
->flags
&= ~FTRACE_FL_REGS
;
1753 * If the rec had TRAMP enabled, then it needs to
1754 * be cleared. As TRAMP can only be enabled iff
1755 * there is only a single ops attached to it.
1756 * In otherwords, always disable it on decrementing.
1757 * In the future, we may set it if rec count is
1758 * decremented to one, and the ops that is left
1761 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1764 * flags will be cleared in ftrace_check_record()
1765 * if rec count is zero.
1770 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1771 update
|= ftrace_test_record(rec
, 1) != FTRACE_UPDATE_IGNORE
;
1773 /* Shortcut, if we handled all records, we are done. */
1774 if (!all
&& count
== hash
->count
)
1776 } while_for_each_ftrace_rec();
1781 static bool ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1784 return __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1787 static bool ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1790 return __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1793 static void ftrace_hash_rec_update_modify(struct ftrace_ops
*ops
,
1794 int filter_hash
, int inc
)
1796 struct ftrace_ops
*op
;
1798 __ftrace_hash_rec_update(ops
, filter_hash
, inc
);
1800 if (ops
->func_hash
!= &global_ops
.local_hash
)
1804 * If the ops shares the global_ops hash, then we need to update
1805 * all ops that are enabled and use this hash.
1807 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1811 if (op
->func_hash
== &global_ops
.local_hash
)
1812 __ftrace_hash_rec_update(op
, filter_hash
, inc
);
1813 } while_for_each_ftrace_op(op
);
1816 static void ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
,
1819 ftrace_hash_rec_update_modify(ops
, filter_hash
, 0);
1822 static void ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
,
1825 ftrace_hash_rec_update_modify(ops
, filter_hash
, 1);
1829 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1830 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1831 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1832 * Note that old_hash and new_hash has below meanings
1833 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1834 * - If the hash is EMPTY_HASH, it hits nothing
1835 * - Anything else hits the recs which match the hash entries.
1837 static int __ftrace_hash_update_ipmodify(struct ftrace_ops
*ops
,
1838 struct ftrace_hash
*old_hash
,
1839 struct ftrace_hash
*new_hash
)
1841 struct ftrace_page
*pg
;
1842 struct dyn_ftrace
*rec
, *end
= NULL
;
1845 /* Only update if the ops has been registered */
1846 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1849 if (!(ops
->flags
& FTRACE_OPS_FL_IPMODIFY
))
1853 * Since the IPMODIFY is a very address sensitive action, we do not
1854 * allow ftrace_ops to set all functions to new hash.
1856 if (!new_hash
|| !old_hash
)
1859 /* Update rec->flags */
1860 do_for_each_ftrace_rec(pg
, rec
) {
1862 if (rec
->flags
& FTRACE_FL_DISABLED
)
1865 /* We need to update only differences of filter_hash */
1866 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1867 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1868 if (in_old
== in_new
)
1872 /* New entries must ensure no others are using it */
1873 if (rec
->flags
& FTRACE_FL_IPMODIFY
)
1875 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1876 } else /* Removed entry */
1877 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1878 } while_for_each_ftrace_rec();
1885 /* Roll back what we did above */
1886 do_for_each_ftrace_rec(pg
, rec
) {
1888 if (rec
->flags
& FTRACE_FL_DISABLED
)
1894 in_old
= !!ftrace_lookup_ip(old_hash
, rec
->ip
);
1895 in_new
= !!ftrace_lookup_ip(new_hash
, rec
->ip
);
1896 if (in_old
== in_new
)
1900 rec
->flags
&= ~FTRACE_FL_IPMODIFY
;
1902 rec
->flags
|= FTRACE_FL_IPMODIFY
;
1903 } while_for_each_ftrace_rec();
1909 static int ftrace_hash_ipmodify_enable(struct ftrace_ops
*ops
)
1911 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1913 if (ftrace_hash_empty(hash
))
1916 return __ftrace_hash_update_ipmodify(ops
, EMPTY_HASH
, hash
);
1919 /* Disabling always succeeds */
1920 static void ftrace_hash_ipmodify_disable(struct ftrace_ops
*ops
)
1922 struct ftrace_hash
*hash
= ops
->func_hash
->filter_hash
;
1924 if (ftrace_hash_empty(hash
))
1927 __ftrace_hash_update_ipmodify(ops
, hash
, EMPTY_HASH
);
1930 static int ftrace_hash_ipmodify_update(struct ftrace_ops
*ops
,
1931 struct ftrace_hash
*new_hash
)
1933 struct ftrace_hash
*old_hash
= ops
->func_hash
->filter_hash
;
1935 if (ftrace_hash_empty(old_hash
))
1938 if (ftrace_hash_empty(new_hash
))
1941 return __ftrace_hash_update_ipmodify(ops
, old_hash
, new_hash
);
1944 static void print_ip_ins(const char *fmt
, const unsigned char *p
)
1948 printk(KERN_CONT
"%s", fmt
);
1950 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1951 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1954 static struct ftrace_ops
*
1955 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
);
1956 static struct ftrace_ops
*
1957 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
, struct ftrace_ops
*ops
);
1959 enum ftrace_bug_type ftrace_bug_type
;
1960 const void *ftrace_expected
;
1962 static void print_bug_type(void)
1964 switch (ftrace_bug_type
) {
1965 case FTRACE_BUG_UNKNOWN
:
1967 case FTRACE_BUG_INIT
:
1968 pr_info("Initializing ftrace call sites\n");
1970 case FTRACE_BUG_NOP
:
1971 pr_info("Setting ftrace call site to NOP\n");
1973 case FTRACE_BUG_CALL
:
1974 pr_info("Setting ftrace call site to call ftrace function\n");
1976 case FTRACE_BUG_UPDATE
:
1977 pr_info("Updating ftrace call site to call a different ftrace function\n");
1983 * ftrace_bug - report and shutdown function tracer
1984 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1985 * @rec: The record that failed
1987 * The arch code that enables or disables the function tracing
1988 * can call ftrace_bug() when it has detected a problem in
1989 * modifying the code. @failed should be one of either:
1990 * EFAULT - if the problem happens on reading the @ip address
1991 * EINVAL - if what is read at @ip is not what was expected
1992 * EPERM - if the problem happens on writing to the @ip address
1994 void ftrace_bug(int failed
, struct dyn_ftrace
*rec
)
1996 unsigned long ip
= rec
? rec
->ip
: 0;
2000 FTRACE_WARN_ON_ONCE(1);
2001 pr_info("ftrace faulted on modifying ");
2005 FTRACE_WARN_ON_ONCE(1);
2006 pr_info("ftrace failed to modify ");
2008 print_ip_ins(" actual: ", (unsigned char *)ip
);
2010 if (ftrace_expected
) {
2011 print_ip_ins(" expected: ", ftrace_expected
);
2016 FTRACE_WARN_ON_ONCE(1);
2017 pr_info("ftrace faulted on writing ");
2021 FTRACE_WARN_ON_ONCE(1);
2022 pr_info("ftrace faulted on unknown error ");
2027 struct ftrace_ops
*ops
= NULL
;
2029 pr_info("ftrace record flags: %lx\n", rec
->flags
);
2030 pr_cont(" (%ld)%s", ftrace_rec_count(rec
),
2031 rec
->flags
& FTRACE_FL_REGS
? " R" : " ");
2032 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2033 ops
= ftrace_find_tramp_ops_any(rec
);
2036 pr_cont("\ttramp: %pS (%pS)",
2037 (void *)ops
->trampoline
,
2039 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
2042 pr_cont("\ttramp: ERROR!");
2045 ip
= ftrace_get_addr_curr(rec
);
2046 pr_cont("\n expected tramp: %lx\n", ip
);
2050 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
2052 unsigned long flag
= 0UL;
2054 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2056 if (rec
->flags
& FTRACE_FL_DISABLED
)
2057 return FTRACE_UPDATE_IGNORE
;
2060 * If we are updating calls:
2062 * If the record has a ref count, then we need to enable it
2063 * because someone is using it.
2065 * Otherwise we make sure its disabled.
2067 * If we are disabling calls, then disable all records that
2070 if (enable
&& ftrace_rec_count(rec
))
2071 flag
= FTRACE_FL_ENABLED
;
2074 * If enabling and the REGS flag does not match the REGS_EN, or
2075 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2076 * this record. Set flags to fail the compare against ENABLED.
2079 if (!(rec
->flags
& FTRACE_FL_REGS
) !=
2080 !(rec
->flags
& FTRACE_FL_REGS_EN
))
2081 flag
|= FTRACE_FL_REGS
;
2083 if (!(rec
->flags
& FTRACE_FL_TRAMP
) !=
2084 !(rec
->flags
& FTRACE_FL_TRAMP_EN
))
2085 flag
|= FTRACE_FL_TRAMP
;
2088 /* If the state of this record hasn't changed, then do nothing */
2089 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
2090 return FTRACE_UPDATE_IGNORE
;
2093 /* Save off if rec is being enabled (for return value) */
2094 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
2097 rec
->flags
|= FTRACE_FL_ENABLED
;
2098 if (flag
& FTRACE_FL_REGS
) {
2099 if (rec
->flags
& FTRACE_FL_REGS
)
2100 rec
->flags
|= FTRACE_FL_REGS_EN
;
2102 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
2104 if (flag
& FTRACE_FL_TRAMP
) {
2105 if (rec
->flags
& FTRACE_FL_TRAMP
)
2106 rec
->flags
|= FTRACE_FL_TRAMP_EN
;
2108 rec
->flags
&= ~FTRACE_FL_TRAMP_EN
;
2113 * If this record is being updated from a nop, then
2114 * return UPDATE_MAKE_CALL.
2116 * return UPDATE_MODIFY_CALL to tell the caller to convert
2117 * from the save regs, to a non-save regs function or
2118 * vice versa, or from a trampoline call.
2120 if (flag
& FTRACE_FL_ENABLED
) {
2121 ftrace_bug_type
= FTRACE_BUG_CALL
;
2122 return FTRACE_UPDATE_MAKE_CALL
;
2125 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2126 return FTRACE_UPDATE_MODIFY_CALL
;
2130 /* If there's no more users, clear all flags */
2131 if (!ftrace_rec_count(rec
))
2135 * Just disable the record, but keep the ops TRAMP
2136 * and REGS states. The _EN flags must be disabled though.
2138 rec
->flags
&= ~(FTRACE_FL_ENABLED
| FTRACE_FL_TRAMP_EN
|
2142 ftrace_bug_type
= FTRACE_BUG_NOP
;
2143 return FTRACE_UPDATE_MAKE_NOP
;
2147 * ftrace_update_record, set a record that now is tracing or not
2148 * @rec: the record to update
2149 * @enable: set to 1 if the record is tracing, zero to force disable
2151 * The records that represent all functions that can be traced need
2152 * to be updated when tracing has been enabled.
2154 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
2156 return ftrace_check_record(rec
, enable
, 1);
2160 * ftrace_test_record, check if the record has been enabled or not
2161 * @rec: the record to test
2162 * @enable: set to 1 to check if enabled, 0 if it is disabled
2164 * The arch code may need to test if a record is already set to
2165 * tracing to determine how to modify the function code that it
2168 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
2170 return ftrace_check_record(rec
, enable
, 0);
2173 static struct ftrace_ops
*
2174 ftrace_find_tramp_ops_any(struct dyn_ftrace
*rec
)
2176 struct ftrace_ops
*op
;
2177 unsigned long ip
= rec
->ip
;
2179 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2181 if (!op
->trampoline
)
2184 if (hash_contains_ip(ip
, op
->func_hash
))
2186 } while_for_each_ftrace_op(op
);
2191 static struct ftrace_ops
*
2192 ftrace_find_tramp_ops_next(struct dyn_ftrace
*rec
,
2193 struct ftrace_ops
*op
)
2195 unsigned long ip
= rec
->ip
;
2197 while_for_each_ftrace_op(op
) {
2199 if (!op
->trampoline
)
2202 if (hash_contains_ip(ip
, op
->func_hash
))
2209 static struct ftrace_ops
*
2210 ftrace_find_tramp_ops_curr(struct dyn_ftrace
*rec
)
2212 struct ftrace_ops
*op
;
2213 unsigned long ip
= rec
->ip
;
2216 * Need to check removed ops first.
2217 * If they are being removed, and this rec has a tramp,
2218 * and this rec is in the ops list, then it would be the
2219 * one with the tramp.
2222 if (hash_contains_ip(ip
, &removed_ops
->old_hash
))
2227 * Need to find the current trampoline for a rec.
2228 * Now, a trampoline is only attached to a rec if there
2229 * was a single 'ops' attached to it. But this can be called
2230 * when we are adding another op to the rec or removing the
2231 * current one. Thus, if the op is being added, we can
2232 * ignore it because it hasn't attached itself to the rec
2235 * If an ops is being modified (hooking to different functions)
2236 * then we don't care about the new functions that are being
2237 * added, just the old ones (that are probably being removed).
2239 * If we are adding an ops to a function that already is using
2240 * a trampoline, it needs to be removed (trampolines are only
2241 * for single ops connected), then an ops that is not being
2242 * modified also needs to be checked.
2244 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2246 if (!op
->trampoline
)
2250 * If the ops is being added, it hasn't gotten to
2251 * the point to be removed from this tree yet.
2253 if (op
->flags
& FTRACE_OPS_FL_ADDING
)
2258 * If the ops is being modified and is in the old
2259 * hash, then it is probably being removed from this
2262 if ((op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2263 hash_contains_ip(ip
, &op
->old_hash
))
2266 * If the ops is not being added or modified, and it's
2267 * in its normal filter hash, then this must be the one
2270 if (!(op
->flags
& FTRACE_OPS_FL_MODIFYING
) &&
2271 hash_contains_ip(ip
, op
->func_hash
))
2274 } while_for_each_ftrace_op(op
);
2279 static struct ftrace_ops
*
2280 ftrace_find_tramp_ops_new(struct dyn_ftrace
*rec
)
2282 struct ftrace_ops
*op
;
2283 unsigned long ip
= rec
->ip
;
2285 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2286 /* pass rec in as regs to have non-NULL val */
2287 if (hash_contains_ip(ip
, op
->func_hash
))
2289 } while_for_each_ftrace_op(op
);
2295 * ftrace_get_addr_new - Get the call address to set to
2296 * @rec: The ftrace record descriptor
2298 * If the record has the FTRACE_FL_REGS set, that means that it
2299 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2300 * is not not set, then it wants to convert to the normal callback.
2302 * Returns the address of the trampoline to set to
2304 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
)
2306 struct ftrace_ops
*ops
;
2308 /* Trampolines take precedence over regs */
2309 if (rec
->flags
& FTRACE_FL_TRAMP
) {
2310 ops
= ftrace_find_tramp_ops_new(rec
);
2311 if (FTRACE_WARN_ON(!ops
|| !ops
->trampoline
)) {
2312 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2313 (void *)rec
->ip
, (void *)rec
->ip
, rec
->flags
);
2314 /* Ftrace is shutting down, return anything */
2315 return (unsigned long)FTRACE_ADDR
;
2317 return ops
->trampoline
;
2320 if (rec
->flags
& FTRACE_FL_REGS
)
2321 return (unsigned long)FTRACE_REGS_ADDR
;
2323 return (unsigned long)FTRACE_ADDR
;
2327 * ftrace_get_addr_curr - Get the call address that is already there
2328 * @rec: The ftrace record descriptor
2330 * The FTRACE_FL_REGS_EN is set when the record already points to
2331 * a function that saves all the regs. Basically the '_EN' version
2332 * represents the current state of the function.
2334 * Returns the address of the trampoline that is currently being called
2336 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
)
2338 struct ftrace_ops
*ops
;
2340 /* Trampolines take precedence over regs */
2341 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2342 ops
= ftrace_find_tramp_ops_curr(rec
);
2343 if (FTRACE_WARN_ON(!ops
)) {
2344 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2345 (void *)rec
->ip
, (void *)rec
->ip
);
2346 /* Ftrace is shutting down, return anything */
2347 return (unsigned long)FTRACE_ADDR
;
2349 return ops
->trampoline
;
2352 if (rec
->flags
& FTRACE_FL_REGS_EN
)
2353 return (unsigned long)FTRACE_REGS_ADDR
;
2355 return (unsigned long)FTRACE_ADDR
;
2359 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
2361 unsigned long ftrace_old_addr
;
2362 unsigned long ftrace_addr
;
2365 ftrace_addr
= ftrace_get_addr_new(rec
);
2367 /* This needs to be done before we call ftrace_update_record */
2368 ftrace_old_addr
= ftrace_get_addr_curr(rec
);
2370 ret
= ftrace_update_record(rec
, enable
);
2372 ftrace_bug_type
= FTRACE_BUG_UNKNOWN
;
2375 case FTRACE_UPDATE_IGNORE
:
2378 case FTRACE_UPDATE_MAKE_CALL
:
2379 ftrace_bug_type
= FTRACE_BUG_CALL
;
2380 return ftrace_make_call(rec
, ftrace_addr
);
2382 case FTRACE_UPDATE_MAKE_NOP
:
2383 ftrace_bug_type
= FTRACE_BUG_NOP
;
2384 return ftrace_make_nop(NULL
, rec
, ftrace_old_addr
);
2386 case FTRACE_UPDATE_MODIFY_CALL
:
2387 ftrace_bug_type
= FTRACE_BUG_UPDATE
;
2388 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
2391 return -1; /* unknown ftrace bug */
2394 void __weak
ftrace_replace_code(int mod_flags
)
2396 struct dyn_ftrace
*rec
;
2397 struct ftrace_page
*pg
;
2398 int enable
= mod_flags
& FTRACE_MODIFY_ENABLE_FL
;
2399 int schedulable
= mod_flags
& FTRACE_MODIFY_MAY_SLEEP_FL
;
2402 if (unlikely(ftrace_disabled
))
2405 do_for_each_ftrace_rec(pg
, rec
) {
2407 if (rec
->flags
& FTRACE_FL_DISABLED
)
2410 failed
= __ftrace_replace_code(rec
, enable
);
2412 ftrace_bug(failed
, rec
);
2413 /* Stop processing */
2418 } while_for_each_ftrace_rec();
2421 struct ftrace_rec_iter
{
2422 struct ftrace_page
*pg
;
2427 * ftrace_rec_iter_start, start up iterating over traced functions
2429 * Returns an iterator handle that is used to iterate over all
2430 * the records that represent address locations where functions
2433 * May return NULL if no records are available.
2435 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
2438 * We only use a single iterator.
2439 * Protected by the ftrace_lock mutex.
2441 static struct ftrace_rec_iter ftrace_rec_iter
;
2442 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
2444 iter
->pg
= ftrace_pages_start
;
2447 /* Could have empty pages */
2448 while (iter
->pg
&& !iter
->pg
->index
)
2449 iter
->pg
= iter
->pg
->next
;
2458 * ftrace_rec_iter_next, get the next record to process.
2459 * @iter: The handle to the iterator.
2461 * Returns the next iterator after the given iterator @iter.
2463 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
2467 if (iter
->index
>= iter
->pg
->index
) {
2468 iter
->pg
= iter
->pg
->next
;
2471 /* Could have empty pages */
2472 while (iter
->pg
&& !iter
->pg
->index
)
2473 iter
->pg
= iter
->pg
->next
;
2483 * ftrace_rec_iter_record, get the record at the iterator location
2484 * @iter: The current iterator location
2486 * Returns the record that the current @iter is at.
2488 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
2490 return &iter
->pg
->records
[iter
->index
];
2494 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
2498 if (unlikely(ftrace_disabled
))
2501 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
2503 ftrace_bug_type
= FTRACE_BUG_INIT
;
2504 ftrace_bug(ret
, rec
);
2511 * archs can override this function if they must do something
2512 * before the modifying code is performed.
2514 int __weak
ftrace_arch_code_modify_prepare(void)
2520 * archs can override this function if they must do something
2521 * after the modifying code is performed.
2523 int __weak
ftrace_arch_code_modify_post_process(void)
2528 void ftrace_modify_all_code(int command
)
2530 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
2534 if (command
& FTRACE_MAY_SLEEP
)
2535 mod_flags
= FTRACE_MODIFY_MAY_SLEEP_FL
;
2538 * If the ftrace_caller calls a ftrace_ops func directly,
2539 * we need to make sure that it only traces functions it
2540 * expects to trace. When doing the switch of functions,
2541 * we need to update to the ftrace_ops_list_func first
2542 * before the transition between old and new calls are set,
2543 * as the ftrace_ops_list_func will check the ops hashes
2544 * to make sure the ops are having the right functions
2548 err
= ftrace_update_ftrace_func(ftrace_ops_list_func
);
2549 if (FTRACE_WARN_ON(err
))
2553 if (command
& FTRACE_UPDATE_CALLS
)
2554 ftrace_replace_code(mod_flags
| FTRACE_MODIFY_ENABLE_FL
);
2555 else if (command
& FTRACE_DISABLE_CALLS
)
2556 ftrace_replace_code(mod_flags
);
2558 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
) {
2559 function_trace_op
= set_function_trace_op
;
2561 /* If irqs are disabled, we are in stop machine */
2562 if (!irqs_disabled())
2563 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2564 err
= ftrace_update_ftrace_func(ftrace_trace_function
);
2565 if (FTRACE_WARN_ON(err
))
2569 if (command
& FTRACE_START_FUNC_RET
)
2570 err
= ftrace_enable_ftrace_graph_caller();
2571 else if (command
& FTRACE_STOP_FUNC_RET
)
2572 err
= ftrace_disable_ftrace_graph_caller();
2573 FTRACE_WARN_ON(err
);
2576 static int __ftrace_modify_code(void *data
)
2578 int *command
= data
;
2580 ftrace_modify_all_code(*command
);
2586 * ftrace_run_stop_machine, go back to the stop machine method
2587 * @command: The command to tell ftrace what to do
2589 * If an arch needs to fall back to the stop machine method, the
2590 * it can call this function.
2592 void ftrace_run_stop_machine(int command
)
2594 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2598 * arch_ftrace_update_code, modify the code to trace or not trace
2599 * @command: The command that needs to be done
2601 * Archs can override this function if it does not need to
2602 * run stop_machine() to modify code.
2604 void __weak
arch_ftrace_update_code(int command
)
2606 ftrace_run_stop_machine(command
);
2609 static void ftrace_run_update_code(int command
)
2613 ret
= ftrace_arch_code_modify_prepare();
2614 FTRACE_WARN_ON(ret
);
2619 * By default we use stop_machine() to modify the code.
2620 * But archs can do what ever they want as long as it
2621 * is safe. The stop_machine() is the safest, but also
2622 * produces the most overhead.
2624 arch_ftrace_update_code(command
);
2626 ret
= ftrace_arch_code_modify_post_process();
2627 FTRACE_WARN_ON(ret
);
2630 static void ftrace_run_modify_code(struct ftrace_ops
*ops
, int command
,
2631 struct ftrace_ops_hash
*old_hash
)
2633 ops
->flags
|= FTRACE_OPS_FL_MODIFYING
;
2634 ops
->old_hash
.filter_hash
= old_hash
->filter_hash
;
2635 ops
->old_hash
.notrace_hash
= old_hash
->notrace_hash
;
2636 ftrace_run_update_code(command
);
2637 ops
->old_hash
.filter_hash
= NULL
;
2638 ops
->old_hash
.notrace_hash
= NULL
;
2639 ops
->flags
&= ~FTRACE_OPS_FL_MODIFYING
;
2642 static ftrace_func_t saved_ftrace_func
;
2643 static int ftrace_start_up
;
2645 void __weak
arch_ftrace_trampoline_free(struct ftrace_ops
*ops
)
2649 static void ftrace_startup_enable(int command
)
2651 if (saved_ftrace_func
!= ftrace_trace_function
) {
2652 saved_ftrace_func
= ftrace_trace_function
;
2653 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2656 if (!command
|| !ftrace_enabled
)
2659 ftrace_run_update_code(command
);
2662 static void ftrace_startup_all(int command
)
2664 update_all_ops
= true;
2665 ftrace_startup_enable(command
);
2666 update_all_ops
= false;
2669 int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2673 if (unlikely(ftrace_disabled
))
2676 ret
= __register_ftrace_function(ops
);
2683 * Note that ftrace probes uses this to start up
2684 * and modify functions it will probe. But we still
2685 * set the ADDING flag for modification, as probes
2686 * do not have trampolines. If they add them in the
2687 * future, then the probes will need to distinguish
2688 * between adding and updating probes.
2690 ops
->flags
|= FTRACE_OPS_FL_ENABLED
| FTRACE_OPS_FL_ADDING
;
2692 ret
= ftrace_hash_ipmodify_enable(ops
);
2694 /* Rollback registration process */
2695 __unregister_ftrace_function(ops
);
2697 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2701 if (ftrace_hash_rec_enable(ops
, 1))
2702 command
|= FTRACE_UPDATE_CALLS
;
2704 ftrace_startup_enable(command
);
2706 ops
->flags
&= ~FTRACE_OPS_FL_ADDING
;
2711 int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2715 if (unlikely(ftrace_disabled
))
2718 ret
= __unregister_ftrace_function(ops
);
2724 * Just warn in case of unbalance, no need to kill ftrace, it's not
2725 * critical but the ftrace_call callers may be never nopped again after
2726 * further ftrace uses.
2728 WARN_ON_ONCE(ftrace_start_up
< 0);
2730 /* Disabling ipmodify never fails */
2731 ftrace_hash_ipmodify_disable(ops
);
2733 if (ftrace_hash_rec_disable(ops
, 1))
2734 command
|= FTRACE_UPDATE_CALLS
;
2736 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2738 if (saved_ftrace_func
!= ftrace_trace_function
) {
2739 saved_ftrace_func
= ftrace_trace_function
;
2740 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2743 if (!command
|| !ftrace_enabled
) {
2745 * If these are dynamic or per_cpu ops, they still
2746 * need their data freed. Since, function tracing is
2747 * not currently active, we can just free them
2748 * without synchronizing all CPUs.
2750 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
)
2757 * If the ops uses a trampoline, then it needs to be
2758 * tested first on update.
2760 ops
->flags
|= FTRACE_OPS_FL_REMOVING
;
2763 /* The trampoline logic checks the old hashes */
2764 ops
->old_hash
.filter_hash
= ops
->func_hash
->filter_hash
;
2765 ops
->old_hash
.notrace_hash
= ops
->func_hash
->notrace_hash
;
2767 ftrace_run_update_code(command
);
2770 * If there's no more ops registered with ftrace, run a
2771 * sanity check to make sure all rec flags are cleared.
2773 if (rcu_dereference_protected(ftrace_ops_list
,
2774 lockdep_is_held(&ftrace_lock
)) == &ftrace_list_end
) {
2775 struct ftrace_page
*pg
;
2776 struct dyn_ftrace
*rec
;
2778 do_for_each_ftrace_rec(pg
, rec
) {
2779 if (FTRACE_WARN_ON_ONCE(rec
->flags
& ~FTRACE_FL_DISABLED
))
2780 pr_warn(" %pS flags:%lx\n",
2781 (void *)rec
->ip
, rec
->flags
);
2782 } while_for_each_ftrace_rec();
2785 ops
->old_hash
.filter_hash
= NULL
;
2786 ops
->old_hash
.notrace_hash
= NULL
;
2789 ops
->flags
&= ~FTRACE_OPS_FL_REMOVING
;
2792 * Dynamic ops may be freed, we must make sure that all
2793 * callers are done before leaving this function.
2794 * The same goes for freeing the per_cpu data of the per_cpu
2797 if (ops
->flags
& FTRACE_OPS_FL_DYNAMIC
) {
2799 * We need to do a hard force of sched synchronization.
2800 * This is because we use preempt_disable() to do RCU, but
2801 * the function tracers can be called where RCU is not watching
2802 * (like before user_exit()). We can not rely on the RCU
2803 * infrastructure to do the synchronization, thus we must do it
2806 schedule_on_each_cpu(ftrace_sync
);
2809 * When the kernel is preeptive, tasks can be preempted
2810 * while on a ftrace trampoline. Just scheduling a task on
2811 * a CPU is not good enough to flush them. Calling
2812 * synchornize_rcu_tasks() will wait for those tasks to
2813 * execute and either schedule voluntarily or enter user space.
2815 if (IS_ENABLED(CONFIG_PREEMPT
))
2816 synchronize_rcu_tasks();
2819 arch_ftrace_trampoline_free(ops
);
2825 static void ftrace_startup_sysctl(void)
2829 if (unlikely(ftrace_disabled
))
2832 /* Force update next time */
2833 saved_ftrace_func
= NULL
;
2834 /* ftrace_start_up is true if we want ftrace running */
2835 if (ftrace_start_up
) {
2836 command
= FTRACE_UPDATE_CALLS
;
2837 if (ftrace_graph_active
)
2838 command
|= FTRACE_START_FUNC_RET
;
2839 ftrace_startup_enable(command
);
2843 static void ftrace_shutdown_sysctl(void)
2847 if (unlikely(ftrace_disabled
))
2850 /* ftrace_start_up is true if ftrace is running */
2851 if (ftrace_start_up
) {
2852 command
= FTRACE_DISABLE_CALLS
;
2853 if (ftrace_graph_active
)
2854 command
|= FTRACE_STOP_FUNC_RET
;
2855 ftrace_run_update_code(command
);
2859 static u64 ftrace_update_time
;
2860 unsigned long ftrace_update_tot_cnt
;
2862 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2865 * Filter_hash being empty will default to trace module.
2866 * But notrace hash requires a test of individual module functions.
2868 return ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2869 ftrace_hash_empty(ops
->func_hash
->notrace_hash
);
2873 * Check if the current ops references the record.
2875 * If the ops traces all functions, then it was already accounted for.
2876 * If the ops does not trace the current record function, skip it.
2877 * If the ops ignores the function via notrace filter, skip it.
2880 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2882 /* If ops isn't enabled, ignore it */
2883 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2886 /* If ops traces all then it includes this function */
2887 if (ops_traces_mod(ops
))
2890 /* The function must be in the filter */
2891 if (!ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2892 !__ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))
2895 /* If in notrace hash, we ignore it too */
2896 if (ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
))
2902 static int ftrace_update_code(struct module
*mod
, struct ftrace_page
*new_pgs
)
2904 struct ftrace_page
*pg
;
2905 struct dyn_ftrace
*p
;
2907 unsigned long update_cnt
= 0;
2908 unsigned long rec_flags
= 0;
2911 start
= ftrace_now(raw_smp_processor_id());
2914 * When a module is loaded, this function is called to convert
2915 * the calls to mcount in its text to nops, and also to create
2916 * an entry in the ftrace data. Now, if ftrace is activated
2917 * after this call, but before the module sets its text to
2918 * read-only, the modification of enabling ftrace can fail if
2919 * the read-only is done while ftrace is converting the calls.
2920 * To prevent this, the module's records are set as disabled
2921 * and will be enabled after the call to set the module's text
2925 rec_flags
|= FTRACE_FL_DISABLED
;
2927 for (pg
= new_pgs
; pg
; pg
= pg
->next
) {
2929 for (i
= 0; i
< pg
->index
; i
++) {
2931 /* If something went wrong, bail without enabling anything */
2932 if (unlikely(ftrace_disabled
))
2935 p
= &pg
->records
[i
];
2936 p
->flags
= rec_flags
;
2938 #ifndef CC_USING_NOP_MCOUNT
2940 * Do the initial record conversion from mcount jump
2941 * to the NOP instructions.
2943 if (!ftrace_code_disable(mod
, p
))
2951 stop
= ftrace_now(raw_smp_processor_id());
2952 ftrace_update_time
= stop
- start
;
2953 ftrace_update_tot_cnt
+= update_cnt
;
2958 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2963 if (WARN_ON(!count
))
2966 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2969 * We want to fill as much as possible. No more than a page
2972 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2976 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2979 /* if we can't allocate this size, try something smaller */
2986 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2995 static struct ftrace_page
*
2996 ftrace_allocate_pages(unsigned long num_to_init
)
2998 struct ftrace_page
*start_pg
;
2999 struct ftrace_page
*pg
;
3006 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3011 * Try to allocate as much as possible in one continues
3012 * location that fills in all of the space. We want to
3013 * waste as little space as possible.
3016 cnt
= ftrace_allocate_records(pg
, num_to_init
);
3024 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
3036 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
3037 free_pages((unsigned long)pg
->records
, order
);
3038 start_pg
= pg
->next
;
3042 pr_info("ftrace: FAILED to allocate memory for functions\n");
3046 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3048 struct ftrace_iterator
{
3052 struct ftrace_page
*pg
;
3053 struct dyn_ftrace
*func
;
3054 struct ftrace_func_probe
*probe
;
3055 struct ftrace_func_entry
*probe_entry
;
3056 struct trace_parser parser
;
3057 struct ftrace_hash
*hash
;
3058 struct ftrace_ops
*ops
;
3059 struct trace_array
*tr
;
3060 struct list_head
*mod_list
;
3067 t_probe_next(struct seq_file
*m
, loff_t
*pos
)
3069 struct ftrace_iterator
*iter
= m
->private;
3070 struct trace_array
*tr
= iter
->ops
->private;
3071 struct list_head
*func_probes
;
3072 struct ftrace_hash
*hash
;
3073 struct list_head
*next
;
3074 struct hlist_node
*hnd
= NULL
;
3075 struct hlist_head
*hhd
;
3084 func_probes
= &tr
->func_probes
;
3085 if (list_empty(func_probes
))
3089 next
= func_probes
->next
;
3090 iter
->probe
= list_entry(next
, struct ftrace_func_probe
, list
);
3093 if (iter
->probe_entry
)
3094 hnd
= &iter
->probe_entry
->hlist
;
3096 hash
= iter
->probe
->ops
.func_hash
->filter_hash
;
3097 size
= 1 << hash
->size_bits
;
3100 if (iter
->pidx
>= size
) {
3101 if (iter
->probe
->list
.next
== func_probes
)
3103 next
= iter
->probe
->list
.next
;
3104 iter
->probe
= list_entry(next
, struct ftrace_func_probe
, list
);
3105 hash
= iter
->probe
->ops
.func_hash
->filter_hash
;
3106 size
= 1 << hash
->size_bits
;
3110 hhd
= &hash
->buckets
[iter
->pidx
];
3112 if (hlist_empty(hhd
)) {
3128 if (WARN_ON_ONCE(!hnd
))
3131 iter
->probe_entry
= hlist_entry(hnd
, struct ftrace_func_entry
, hlist
);
3136 static void *t_probe_start(struct seq_file
*m
, loff_t
*pos
)
3138 struct ftrace_iterator
*iter
= m
->private;
3142 if (!(iter
->flags
& FTRACE_ITER_DO_PROBES
))
3145 if (iter
->mod_pos
> *pos
)
3149 iter
->probe_entry
= NULL
;
3151 for (l
= 0; l
<= (*pos
- iter
->mod_pos
); ) {
3152 p
= t_probe_next(m
, &l
);
3159 /* Only set this if we have an item */
3160 iter
->flags
|= FTRACE_ITER_PROBE
;
3166 t_probe_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
3168 struct ftrace_func_entry
*probe_entry
;
3169 struct ftrace_probe_ops
*probe_ops
;
3170 struct ftrace_func_probe
*probe
;
3172 probe
= iter
->probe
;
3173 probe_entry
= iter
->probe_entry
;
3175 if (WARN_ON_ONCE(!probe
|| !probe_entry
))
3178 probe_ops
= probe
->probe_ops
;
3180 if (probe_ops
->print
)
3181 return probe_ops
->print(m
, probe_entry
->ip
, probe_ops
, probe
->data
);
3183 seq_printf(m
, "%ps:%ps\n", (void *)probe_entry
->ip
,
3184 (void *)probe_ops
->func
);
3190 t_mod_next(struct seq_file
*m
, loff_t
*pos
)
3192 struct ftrace_iterator
*iter
= m
->private;
3193 struct trace_array
*tr
= iter
->tr
;
3198 iter
->mod_list
= iter
->mod_list
->next
;
3200 if (iter
->mod_list
== &tr
->mod_trace
||
3201 iter
->mod_list
== &tr
->mod_notrace
) {
3202 iter
->flags
&= ~FTRACE_ITER_MOD
;
3206 iter
->mod_pos
= *pos
;
3211 static void *t_mod_start(struct seq_file
*m
, loff_t
*pos
)
3213 struct ftrace_iterator
*iter
= m
->private;
3217 if (iter
->func_pos
> *pos
)
3220 iter
->mod_pos
= iter
->func_pos
;
3222 /* probes are only available if tr is set */
3226 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
3227 p
= t_mod_next(m
, &l
);
3232 iter
->flags
&= ~FTRACE_ITER_MOD
;
3233 return t_probe_start(m
, pos
);
3236 /* Only set this if we have an item */
3237 iter
->flags
|= FTRACE_ITER_MOD
;
3243 t_mod_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
3245 struct ftrace_mod_load
*ftrace_mod
;
3246 struct trace_array
*tr
= iter
->tr
;
3248 if (WARN_ON_ONCE(!iter
->mod_list
) ||
3249 iter
->mod_list
== &tr
->mod_trace
||
3250 iter
->mod_list
== &tr
->mod_notrace
)
3253 ftrace_mod
= list_entry(iter
->mod_list
, struct ftrace_mod_load
, list
);
3255 if (ftrace_mod
->func
)
3256 seq_printf(m
, "%s", ftrace_mod
->func
);
3260 seq_printf(m
, ":mod:%s\n", ftrace_mod
->module
);
3266 t_func_next(struct seq_file
*m
, loff_t
*pos
)
3268 struct ftrace_iterator
*iter
= m
->private;
3269 struct dyn_ftrace
*rec
= NULL
;
3274 if (iter
->idx
>= iter
->pg
->index
) {
3275 if (iter
->pg
->next
) {
3276 iter
->pg
= iter
->pg
->next
;
3281 rec
= &iter
->pg
->records
[iter
->idx
++];
3282 if (((iter
->flags
& (FTRACE_ITER_FILTER
| FTRACE_ITER_NOTRACE
)) &&
3283 !ftrace_lookup_ip(iter
->hash
, rec
->ip
)) ||
3285 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
3286 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
3296 iter
->pos
= iter
->func_pos
= *pos
;
3303 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
3305 struct ftrace_iterator
*iter
= m
->private;
3306 loff_t l
= *pos
; /* t_probe_start() must use original pos */
3309 if (unlikely(ftrace_disabled
))
3312 if (iter
->flags
& FTRACE_ITER_PROBE
)
3313 return t_probe_next(m
, pos
);
3315 if (iter
->flags
& FTRACE_ITER_MOD
)
3316 return t_mod_next(m
, pos
);
3318 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3319 /* next must increment pos, and t_probe_start does not */
3321 return t_mod_start(m
, &l
);
3324 ret
= t_func_next(m
, pos
);
3327 return t_mod_start(m
, &l
);
3332 static void reset_iter_read(struct ftrace_iterator
*iter
)
3336 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_PROBE
| FTRACE_ITER_MOD
);
3339 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
3341 struct ftrace_iterator
*iter
= m
->private;
3345 mutex_lock(&ftrace_lock
);
3347 if (unlikely(ftrace_disabled
))
3351 * If an lseek was done, then reset and start from beginning.
3353 if (*pos
< iter
->pos
)
3354 reset_iter_read(iter
);
3357 * For set_ftrace_filter reading, if we have the filter
3358 * off, we can short cut and just print out that all
3359 * functions are enabled.
3361 if ((iter
->flags
& (FTRACE_ITER_FILTER
| FTRACE_ITER_NOTRACE
)) &&
3362 ftrace_hash_empty(iter
->hash
)) {
3363 iter
->func_pos
= 1; /* Account for the message */
3365 return t_mod_start(m
, pos
);
3366 iter
->flags
|= FTRACE_ITER_PRINTALL
;
3367 /* reset in case of seek/pread */
3368 iter
->flags
&= ~FTRACE_ITER_PROBE
;
3372 if (iter
->flags
& FTRACE_ITER_MOD
)
3373 return t_mod_start(m
, pos
);
3376 * Unfortunately, we need to restart at ftrace_pages_start
3377 * every time we let go of the ftrace_mutex. This is because
3378 * those pointers can change without the lock.
3380 iter
->pg
= ftrace_pages_start
;
3382 for (l
= 0; l
<= *pos
; ) {
3383 p
= t_func_next(m
, &l
);
3389 return t_mod_start(m
, pos
);
3394 static void t_stop(struct seq_file
*m
, void *p
)
3396 mutex_unlock(&ftrace_lock
);
3400 arch_ftrace_trampoline_func(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
3405 static void add_trampoline_func(struct seq_file
*m
, struct ftrace_ops
*ops
,
3406 struct dyn_ftrace
*rec
)
3410 ptr
= arch_ftrace_trampoline_func(ops
, rec
);
3412 seq_printf(m
, " ->%pS", ptr
);
3415 static int t_show(struct seq_file
*m
, void *v
)
3417 struct ftrace_iterator
*iter
= m
->private;
3418 struct dyn_ftrace
*rec
;
3420 if (iter
->flags
& FTRACE_ITER_PROBE
)
3421 return t_probe_show(m
, iter
);
3423 if (iter
->flags
& FTRACE_ITER_MOD
)
3424 return t_mod_show(m
, iter
);
3426 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
3427 if (iter
->flags
& FTRACE_ITER_NOTRACE
)
3428 seq_puts(m
, "#### no functions disabled ####\n");
3430 seq_puts(m
, "#### all functions enabled ####\n");
3439 seq_printf(m
, "%ps", (void *)rec
->ip
);
3440 if (iter
->flags
& FTRACE_ITER_ENABLED
) {
3441 struct ftrace_ops
*ops
;
3443 seq_printf(m
, " (%ld)%s%s",
3444 ftrace_rec_count(rec
),
3445 rec
->flags
& FTRACE_FL_REGS
? " R" : " ",
3446 rec
->flags
& FTRACE_FL_IPMODIFY
? " I" : " ");
3447 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
3448 ops
= ftrace_find_tramp_ops_any(rec
);
3451 seq_printf(m
, "\ttramp: %pS (%pS)",
3452 (void *)ops
->trampoline
,
3454 add_trampoline_func(m
, ops
, rec
);
3455 ops
= ftrace_find_tramp_ops_next(rec
, ops
);
3458 seq_puts(m
, "\ttramp: ERROR!");
3460 add_trampoline_func(m
, NULL
, rec
);
3469 static const struct seq_operations show_ftrace_seq_ops
= {
3477 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
3479 struct ftrace_iterator
*iter
;
3481 if (unlikely(ftrace_disabled
))
3484 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3488 iter
->pg
= ftrace_pages_start
;
3489 iter
->ops
= &global_ops
;
3495 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
3497 struct ftrace_iterator
*iter
;
3499 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3503 iter
->pg
= ftrace_pages_start
;
3504 iter
->flags
= FTRACE_ITER_ENABLED
;
3505 iter
->ops
= &global_ops
;
3511 * ftrace_regex_open - initialize function tracer filter files
3512 * @ops: The ftrace_ops that hold the hash filters
3513 * @flag: The type of filter to process
3514 * @inode: The inode, usually passed in to your open routine
3515 * @file: The file, usually passed in to your open routine
3517 * ftrace_regex_open() initializes the filter files for the
3518 * @ops. Depending on @flag it may process the filter hash or
3519 * the notrace hash of @ops. With this called from the open
3520 * routine, you can use ftrace_filter_write() for the write
3521 * routine if @flag has FTRACE_ITER_FILTER set, or
3522 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3523 * tracing_lseek() should be used as the lseek routine, and
3524 * release must call ftrace_regex_release().
3527 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
3528 struct inode
*inode
, struct file
*file
)
3530 struct ftrace_iterator
*iter
;
3531 struct ftrace_hash
*hash
;
3532 struct list_head
*mod_head
;
3533 struct trace_array
*tr
= ops
->private;
3536 ftrace_ops_init(ops
);
3538 if (unlikely(ftrace_disabled
))
3541 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
3545 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
3554 mutex_lock(&ops
->func_hash
->regex_lock
);
3556 if (flag
& FTRACE_ITER_NOTRACE
) {
3557 hash
= ops
->func_hash
->notrace_hash
;
3558 mod_head
= tr
? &tr
->mod_notrace
: NULL
;
3560 hash
= ops
->func_hash
->filter_hash
;
3561 mod_head
= tr
? &tr
->mod_trace
: NULL
;
3564 iter
->mod_list
= mod_head
;
3566 if (file
->f_mode
& FMODE_WRITE
) {
3567 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
3569 if (file
->f_flags
& O_TRUNC
) {
3570 iter
->hash
= alloc_ftrace_hash(size_bits
);
3571 clear_ftrace_mod_list(mod_head
);
3573 iter
->hash
= alloc_and_copy_ftrace_hash(size_bits
, hash
);
3577 trace_parser_put(&iter
->parser
);
3585 if (file
->f_mode
& FMODE_READ
) {
3586 iter
->pg
= ftrace_pages_start
;
3588 ret
= seq_open(file
, &show_ftrace_seq_ops
);
3590 struct seq_file
*m
= file
->private_data
;
3594 free_ftrace_hash(iter
->hash
);
3595 trace_parser_put(&iter
->parser
);
3599 file
->private_data
= iter
;
3602 mutex_unlock(&ops
->func_hash
->regex_lock
);
3608 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
3610 struct ftrace_ops
*ops
= inode
->i_private
;
3612 return ftrace_regex_open(ops
,
3613 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_PROBES
,
3618 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
3620 struct ftrace_ops
*ops
= inode
->i_private
;
3622 return ftrace_regex_open(ops
, FTRACE_ITER_NOTRACE
,
3626 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3627 struct ftrace_glob
{
3634 * If symbols in an architecture don't correspond exactly to the user-visible
3635 * name of what they represent, it is possible to define this function to
3636 * perform the necessary adjustments.
3638 char * __weak
arch_ftrace_match_adjust(char *str
, const char *search
)
3643 static int ftrace_match(char *str
, struct ftrace_glob
*g
)
3648 str
= arch_ftrace_match_adjust(str
, g
->search
);
3652 if (strcmp(str
, g
->search
) == 0)
3655 case MATCH_FRONT_ONLY
:
3656 if (strncmp(str
, g
->search
, g
->len
) == 0)
3659 case MATCH_MIDDLE_ONLY
:
3660 if (strstr(str
, g
->search
))
3663 case MATCH_END_ONLY
:
3665 if (slen
>= g
->len
&&
3666 memcmp(str
+ slen
- g
->len
, g
->search
, g
->len
) == 0)
3670 if (glob_match(g
->search
, str
))
3679 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int clear_filter
)
3681 struct ftrace_func_entry
*entry
;
3684 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
3686 /* Do nothing if it doesn't exist */
3690 free_hash_entry(hash
, entry
);
3692 /* Do nothing if it exists */
3696 ret
= add_hash_entry(hash
, rec
->ip
);
3702 add_rec_by_index(struct ftrace_hash
*hash
, struct ftrace_glob
*func_g
,
3705 long index
= simple_strtoul(func_g
->search
, NULL
, 0);
3706 struct ftrace_page
*pg
;
3707 struct dyn_ftrace
*rec
;
3709 /* The index starts at 1 */
3713 do_for_each_ftrace_rec(pg
, rec
) {
3714 if (pg
->index
<= index
) {
3716 /* this is a double loop, break goes to the next page */
3719 rec
= &pg
->records
[index
];
3720 enter_record(hash
, rec
, clear_filter
);
3722 } while_for_each_ftrace_rec();
3727 ftrace_match_record(struct dyn_ftrace
*rec
, struct ftrace_glob
*func_g
,
3728 struct ftrace_glob
*mod_g
, int exclude_mod
)
3730 char str
[KSYM_SYMBOL_LEN
];
3733 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
3736 int mod_matches
= (modname
) ? ftrace_match(modname
, mod_g
) : 0;
3738 /* blank module name to match all modules */
3740 /* blank module globbing: modname xor exclude_mod */
3741 if (!exclude_mod
!= !modname
)
3747 * exclude_mod is set to trace everything but the given
3748 * module. If it is set and the module matches, then
3749 * return 0. If it is not set, and the module doesn't match
3750 * also return 0. Otherwise, check the function to see if
3753 if (!mod_matches
== !exclude_mod
)
3756 /* blank search means to match all funcs in the mod */
3761 return ftrace_match(str
, func_g
);
3765 match_records(struct ftrace_hash
*hash
, char *func
, int len
, char *mod
)
3767 struct ftrace_page
*pg
;
3768 struct dyn_ftrace
*rec
;
3769 struct ftrace_glob func_g
= { .type
= MATCH_FULL
};
3770 struct ftrace_glob mod_g
= { .type
= MATCH_FULL
};
3771 struct ftrace_glob
*mod_match
= (mod
) ? &mod_g
: NULL
;
3772 int exclude_mod
= 0;
3775 int clear_filter
= 0;
3778 func_g
.type
= filter_parse_regex(func
, len
, &func_g
.search
,
3780 func_g
.len
= strlen(func_g
.search
);
3784 mod_g
.type
= filter_parse_regex(mod
, strlen(mod
),
3785 &mod_g
.search
, &exclude_mod
);
3786 mod_g
.len
= strlen(mod_g
.search
);
3789 mutex_lock(&ftrace_lock
);
3791 if (unlikely(ftrace_disabled
))
3794 if (func_g
.type
== MATCH_INDEX
) {
3795 found
= add_rec_by_index(hash
, &func_g
, clear_filter
);
3799 do_for_each_ftrace_rec(pg
, rec
) {
3801 if (rec
->flags
& FTRACE_FL_DISABLED
)
3804 if (ftrace_match_record(rec
, &func_g
, mod_match
, exclude_mod
)) {
3805 ret
= enter_record(hash
, rec
, clear_filter
);
3812 } while_for_each_ftrace_rec();
3814 mutex_unlock(&ftrace_lock
);
3820 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
3822 return match_records(hash
, buff
, len
, NULL
);
3825 static void ftrace_ops_update_code(struct ftrace_ops
*ops
,
3826 struct ftrace_ops_hash
*old_hash
)
3828 struct ftrace_ops
*op
;
3830 if (!ftrace_enabled
)
3833 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
3834 ftrace_run_modify_code(ops
, FTRACE_UPDATE_CALLS
, old_hash
);
3839 * If this is the shared global_ops filter, then we need to
3840 * check if there is another ops that shares it, is enabled.
3841 * If so, we still need to run the modify code.
3843 if (ops
->func_hash
!= &global_ops
.local_hash
)
3846 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
3847 if (op
->func_hash
== &global_ops
.local_hash
&&
3848 op
->flags
& FTRACE_OPS_FL_ENABLED
) {
3849 ftrace_run_modify_code(op
, FTRACE_UPDATE_CALLS
, old_hash
);
3850 /* Only need to do this once */
3853 } while_for_each_ftrace_op(op
);
3856 static int ftrace_hash_move_and_update_ops(struct ftrace_ops
*ops
,
3857 struct ftrace_hash
**orig_hash
,
3858 struct ftrace_hash
*hash
,
3861 struct ftrace_ops_hash old_hash_ops
;
3862 struct ftrace_hash
*old_hash
;
3865 old_hash
= *orig_hash
;
3866 old_hash_ops
.filter_hash
= ops
->func_hash
->filter_hash
;
3867 old_hash_ops
.notrace_hash
= ops
->func_hash
->notrace_hash
;
3868 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3870 ftrace_ops_update_code(ops
, &old_hash_ops
);
3871 free_ftrace_hash_rcu(old_hash
);
3876 static bool module_exists(const char *module
)
3878 /* All modules have the symbol __this_module */
3879 static const char this_mod
[] = "__this_module";
3880 char modname
[MAX_PARAM_PREFIX_LEN
+ sizeof(this_mod
) + 2];
3884 n
= snprintf(modname
, sizeof(modname
), "%s:%s", module
, this_mod
);
3886 if (n
> sizeof(modname
) - 1)
3889 val
= module_kallsyms_lookup_name(modname
);
3893 static int cache_mod(struct trace_array
*tr
,
3894 const char *func
, char *module
, int enable
)
3896 struct ftrace_mod_load
*ftrace_mod
, *n
;
3897 struct list_head
*head
= enable
? &tr
->mod_trace
: &tr
->mod_notrace
;
3900 mutex_lock(&ftrace_lock
);
3902 /* We do not cache inverse filters */
3903 if (func
[0] == '!') {
3907 /* Look to remove this hash */
3908 list_for_each_entry_safe(ftrace_mod
, n
, head
, list
) {
3909 if (strcmp(ftrace_mod
->module
, module
) != 0)
3912 /* no func matches all */
3913 if (strcmp(func
, "*") == 0 ||
3914 (ftrace_mod
->func
&&
3915 strcmp(ftrace_mod
->func
, func
) == 0)) {
3917 free_ftrace_mod(ftrace_mod
);
3925 /* We only care about modules that have not been loaded yet */
3926 if (module_exists(module
))
3929 /* Save this string off, and execute it when the module is loaded */
3930 ret
= ftrace_add_mod(tr
, func
, module
, enable
);
3932 mutex_unlock(&ftrace_lock
);
3938 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3939 int reset
, int enable
);
3941 #ifdef CONFIG_MODULES
3942 static void process_mod_list(struct list_head
*head
, struct ftrace_ops
*ops
,
3943 char *mod
, bool enable
)
3945 struct ftrace_mod_load
*ftrace_mod
, *n
;
3946 struct ftrace_hash
**orig_hash
, *new_hash
;
3947 LIST_HEAD(process_mods
);
3951 mutex_lock(&ops
->func_hash
->regex_lock
);
3954 orig_hash
= &ops
->func_hash
->filter_hash
;
3956 orig_hash
= &ops
->func_hash
->notrace_hash
;
3958 new_hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
,
3961 goto out
; /* warn? */
3963 mutex_lock(&ftrace_lock
);
3965 list_for_each_entry_safe(ftrace_mod
, n
, head
, list
) {
3967 if (strcmp(ftrace_mod
->module
, mod
) != 0)
3970 if (ftrace_mod
->func
)
3971 func
= kstrdup(ftrace_mod
->func
, GFP_KERNEL
);
3973 func
= kstrdup("*", GFP_KERNEL
);
3975 if (!func
) /* warn? */
3978 list_del(&ftrace_mod
->list
);
3979 list_add(&ftrace_mod
->list
, &process_mods
);
3981 /* Use the newly allocated func, as it may be "*" */
3982 kfree(ftrace_mod
->func
);
3983 ftrace_mod
->func
= func
;
3986 mutex_unlock(&ftrace_lock
);
3988 list_for_each_entry_safe(ftrace_mod
, n
, &process_mods
, list
) {
3990 func
= ftrace_mod
->func
;
3992 /* Grabs ftrace_lock, which is why we have this extra step */
3993 match_records(new_hash
, func
, strlen(func
), mod
);
3994 free_ftrace_mod(ftrace_mod
);
3997 if (enable
&& list_empty(head
))
3998 new_hash
->flags
&= ~FTRACE_HASH_FL_MOD
;
4000 mutex_lock(&ftrace_lock
);
4002 ret
= ftrace_hash_move_and_update_ops(ops
, orig_hash
,
4004 mutex_unlock(&ftrace_lock
);
4007 mutex_unlock(&ops
->func_hash
->regex_lock
);
4009 free_ftrace_hash(new_hash
);
4012 static void process_cached_mods(const char *mod_name
)
4014 struct trace_array
*tr
;
4017 mod
= kstrdup(mod_name
, GFP_KERNEL
);
4021 mutex_lock(&trace_types_lock
);
4022 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
) {
4023 if (!list_empty(&tr
->mod_trace
))
4024 process_mod_list(&tr
->mod_trace
, tr
->ops
, mod
, true);
4025 if (!list_empty(&tr
->mod_notrace
))
4026 process_mod_list(&tr
->mod_notrace
, tr
->ops
, mod
, false);
4028 mutex_unlock(&trace_types_lock
);
4035 * We register the module command as a template to show others how
4036 * to register the a command as well.
4040 ftrace_mod_callback(struct trace_array
*tr
, struct ftrace_hash
*hash
,
4041 char *func_orig
, char *cmd
, char *module
, int enable
)
4046 /* match_records() modifies func, and we need the original */
4047 func
= kstrdup(func_orig
, GFP_KERNEL
);
4052 * cmd == 'mod' because we only registered this func
4053 * for the 'mod' ftrace_func_command.
4054 * But if you register one func with multiple commands,
4055 * you can tell which command was used by the cmd
4058 ret
= match_records(hash
, func
, strlen(func
), module
);
4062 return cache_mod(tr
, func_orig
, module
, enable
);
4068 static struct ftrace_func_command ftrace_mod_cmd
= {
4070 .func
= ftrace_mod_callback
,
4073 static int __init
ftrace_mod_cmd_init(void)
4075 return register_ftrace_command(&ftrace_mod_cmd
);
4077 core_initcall(ftrace_mod_cmd_init
);
4079 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
4080 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
4082 struct ftrace_probe_ops
*probe_ops
;
4083 struct ftrace_func_probe
*probe
;
4085 probe
= container_of(op
, struct ftrace_func_probe
, ops
);
4086 probe_ops
= probe
->probe_ops
;
4089 * Disable preemption for these calls to prevent a RCU grace
4090 * period. This syncs the hash iteration and freeing of items
4091 * on the hash. rcu_read_lock is too dangerous here.
4093 preempt_disable_notrace();
4094 probe_ops
->func(ip
, parent_ip
, probe
->tr
, probe_ops
, probe
->data
);
4095 preempt_enable_notrace();
4098 struct ftrace_func_map
{
4099 struct ftrace_func_entry entry
;
4103 struct ftrace_func_mapper
{
4104 struct ftrace_hash hash
;
4108 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4110 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4112 struct ftrace_func_mapper
*allocate_ftrace_func_mapper(void)
4114 struct ftrace_hash
*hash
;
4117 * The mapper is simply a ftrace_hash, but since the entries
4118 * in the hash are not ftrace_func_entry type, we define it
4119 * as a separate structure.
4121 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4122 return (struct ftrace_func_mapper
*)hash
;
4126 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4127 * @mapper: The mapper that has the ip maps
4128 * @ip: the instruction pointer to find the data for
4130 * Returns the data mapped to @ip if found otherwise NULL. The return
4131 * is actually the address of the mapper data pointer. The address is
4132 * returned for use cases where the data is no bigger than a long, and
4133 * the user can use the data pointer as its data instead of having to
4134 * allocate more memory for the reference.
4136 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper
*mapper
,
4139 struct ftrace_func_entry
*entry
;
4140 struct ftrace_func_map
*map
;
4142 entry
= ftrace_lookup_ip(&mapper
->hash
, ip
);
4146 map
= (struct ftrace_func_map
*)entry
;
4151 * ftrace_func_mapper_add_ip - Map some data to an ip
4152 * @mapper: The mapper that has the ip maps
4153 * @ip: The instruction pointer address to map @data to
4154 * @data: The data to map to @ip
4156 * Returns 0 on succes otherwise an error.
4158 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper
*mapper
,
4159 unsigned long ip
, void *data
)
4161 struct ftrace_func_entry
*entry
;
4162 struct ftrace_func_map
*map
;
4164 entry
= ftrace_lookup_ip(&mapper
->hash
, ip
);
4168 map
= kmalloc(sizeof(*map
), GFP_KERNEL
);
4175 __add_hash_entry(&mapper
->hash
, &map
->entry
);
4181 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4182 * @mapper: The mapper that has the ip maps
4183 * @ip: The instruction pointer address to remove the data from
4185 * Returns the data if it is found, otherwise NULL.
4186 * Note, if the data pointer is used as the data itself, (see
4187 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4188 * if the data pointer was set to zero.
4190 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper
*mapper
,
4193 struct ftrace_func_entry
*entry
;
4194 struct ftrace_func_map
*map
;
4197 entry
= ftrace_lookup_ip(&mapper
->hash
, ip
);
4201 map
= (struct ftrace_func_map
*)entry
;
4204 remove_hash_entry(&mapper
->hash
, entry
);
4211 * free_ftrace_func_mapper - free a mapping of ips and data
4212 * @mapper: The mapper that has the ip maps
4213 * @free_func: A function to be called on each data item.
4215 * This is used to free the function mapper. The @free_func is optional
4216 * and can be used if the data needs to be freed as well.
4218 void free_ftrace_func_mapper(struct ftrace_func_mapper
*mapper
,
4219 ftrace_mapper_func free_func
)
4221 struct ftrace_func_entry
*entry
;
4222 struct ftrace_func_map
*map
;
4223 struct hlist_head
*hhd
;
4224 int size
= 1 << mapper
->hash
.size_bits
;
4227 if (free_func
&& mapper
->hash
.count
) {
4228 for (i
= 0; i
< size
; i
++) {
4229 hhd
= &mapper
->hash
.buckets
[i
];
4230 hlist_for_each_entry(entry
, hhd
, hlist
) {
4231 map
= (struct ftrace_func_map
*)entry
;
4236 free_ftrace_hash(&mapper
->hash
);
4239 static void release_probe(struct ftrace_func_probe
*probe
)
4241 struct ftrace_probe_ops
*probe_ops
;
4243 mutex_lock(&ftrace_lock
);
4245 WARN_ON(probe
->ref
<= 0);
4247 /* Subtract the ref that was used to protect this instance */
4251 probe_ops
= probe
->probe_ops
;
4253 * Sending zero as ip tells probe_ops to free
4254 * the probe->data itself
4256 if (probe_ops
->free
)
4257 probe_ops
->free(probe_ops
, probe
->tr
, 0, probe
->data
);
4258 list_del(&probe
->list
);
4261 mutex_unlock(&ftrace_lock
);
4264 static void acquire_probe_locked(struct ftrace_func_probe
*probe
)
4267 * Add one ref to keep it from being freed when releasing the
4268 * ftrace_lock mutex.
4274 register_ftrace_function_probe(char *glob
, struct trace_array
*tr
,
4275 struct ftrace_probe_ops
*probe_ops
,
4278 struct ftrace_func_entry
*entry
;
4279 struct ftrace_func_probe
*probe
;
4280 struct ftrace_hash
**orig_hash
;
4281 struct ftrace_hash
*old_hash
;
4282 struct ftrace_hash
*hash
;
4291 /* We do not support '!' for function probes */
4292 if (WARN_ON(glob
[0] == '!'))
4296 mutex_lock(&ftrace_lock
);
4297 /* Check if the probe_ops is already registered */
4298 list_for_each_entry(probe
, &tr
->func_probes
, list
) {
4299 if (probe
->probe_ops
== probe_ops
)
4302 if (&probe
->list
== &tr
->func_probes
) {
4303 probe
= kzalloc(sizeof(*probe
), GFP_KERNEL
);
4305 mutex_unlock(&ftrace_lock
);
4308 probe
->probe_ops
= probe_ops
;
4309 probe
->ops
.func
= function_trace_probe_call
;
4311 ftrace_ops_init(&probe
->ops
);
4312 list_add(&probe
->list
, &tr
->func_probes
);
4315 acquire_probe_locked(probe
);
4317 mutex_unlock(&ftrace_lock
);
4319 mutex_lock(&probe
->ops
.func_hash
->regex_lock
);
4321 orig_hash
= &probe
->ops
.func_hash
->filter_hash
;
4322 old_hash
= *orig_hash
;
4323 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
4325 ret
= ftrace_match_records(hash
, glob
, strlen(glob
));
4327 /* Nothing found? */
4334 size
= 1 << hash
->size_bits
;
4335 for (i
= 0; i
< size
; i
++) {
4336 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
4337 if (ftrace_lookup_ip(old_hash
, entry
->ip
))
4340 * The caller might want to do something special
4341 * for each function we find. We call the callback
4342 * to give the caller an opportunity to do so.
4344 if (probe_ops
->init
) {
4345 ret
= probe_ops
->init(probe_ops
, tr
,
4349 if (probe_ops
->free
&& count
)
4350 probe_ops
->free(probe_ops
, tr
,
4360 mutex_lock(&ftrace_lock
);
4363 /* Nothing was added? */
4368 ret
= ftrace_hash_move_and_update_ops(&probe
->ops
, orig_hash
,
4373 /* One ref for each new function traced */
4374 probe
->ref
+= count
;
4376 if (!(probe
->ops
.flags
& FTRACE_OPS_FL_ENABLED
))
4377 ret
= ftrace_startup(&probe
->ops
, 0);
4380 mutex_unlock(&ftrace_lock
);
4385 mutex_unlock(&probe
->ops
.func_hash
->regex_lock
);
4386 free_ftrace_hash(hash
);
4388 release_probe(probe
);
4393 if (!probe_ops
->free
|| !count
)
4396 /* Failed to do the move, need to call the free functions */
4397 for (i
= 0; i
< size
; i
++) {
4398 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
4399 if (ftrace_lookup_ip(old_hash
, entry
->ip
))
4401 probe_ops
->free(probe_ops
, tr
, entry
->ip
, probe
->data
);
4408 unregister_ftrace_function_probe_func(char *glob
, struct trace_array
*tr
,
4409 struct ftrace_probe_ops
*probe_ops
)
4411 struct ftrace_ops_hash old_hash_ops
;
4412 struct ftrace_func_entry
*entry
;
4413 struct ftrace_func_probe
*probe
;
4414 struct ftrace_glob func_g
;
4415 struct ftrace_hash
**orig_hash
;
4416 struct ftrace_hash
*old_hash
;
4417 struct ftrace_hash
*hash
= NULL
;
4418 struct hlist_node
*tmp
;
4419 struct hlist_head hhd
;
4420 char str
[KSYM_SYMBOL_LEN
];
4422 int i
, ret
= -ENODEV
;
4425 if (!glob
|| !strlen(glob
) || !strcmp(glob
, "*"))
4426 func_g
.search
= NULL
;
4430 func_g
.type
= filter_parse_regex(glob
, strlen(glob
),
4431 &func_g
.search
, ¬);
4432 func_g
.len
= strlen(func_g
.search
);
4434 /* we do not support '!' for function probes */
4439 mutex_lock(&ftrace_lock
);
4440 /* Check if the probe_ops is already registered */
4441 list_for_each_entry(probe
, &tr
->func_probes
, list
) {
4442 if (probe
->probe_ops
== probe_ops
)
4445 if (&probe
->list
== &tr
->func_probes
)
4446 goto err_unlock_ftrace
;
4449 if (!(probe
->ops
.flags
& FTRACE_OPS_FL_INITIALIZED
))
4450 goto err_unlock_ftrace
;
4452 acquire_probe_locked(probe
);
4454 mutex_unlock(&ftrace_lock
);
4456 mutex_lock(&probe
->ops
.func_hash
->regex_lock
);
4458 orig_hash
= &probe
->ops
.func_hash
->filter_hash
;
4459 old_hash
= *orig_hash
;
4461 if (ftrace_hash_empty(old_hash
))
4464 old_hash_ops
.filter_hash
= old_hash
;
4465 /* Probes only have filters */
4466 old_hash_ops
.notrace_hash
= NULL
;
4469 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, old_hash
);
4473 INIT_HLIST_HEAD(&hhd
);
4475 size
= 1 << hash
->size_bits
;
4476 for (i
= 0; i
< size
; i
++) {
4477 hlist_for_each_entry_safe(entry
, tmp
, &hash
->buckets
[i
], hlist
) {
4479 if (func_g
.search
) {
4480 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
4482 if (!ftrace_match(str
, &func_g
))
4486 remove_hash_entry(hash
, entry
);
4487 hlist_add_head(&entry
->hlist
, &hhd
);
4491 /* Nothing found? */
4497 mutex_lock(&ftrace_lock
);
4499 WARN_ON(probe
->ref
< count
);
4501 probe
->ref
-= count
;
4503 if (ftrace_hash_empty(hash
))
4504 ftrace_shutdown(&probe
->ops
, 0);
4506 ret
= ftrace_hash_move_and_update_ops(&probe
->ops
, orig_hash
,
4509 /* still need to update the function call sites */
4510 if (ftrace_enabled
&& !ftrace_hash_empty(hash
))
4511 ftrace_run_modify_code(&probe
->ops
, FTRACE_UPDATE_CALLS
,
4515 hlist_for_each_entry_safe(entry
, tmp
, &hhd
, hlist
) {
4516 hlist_del(&entry
->hlist
);
4517 if (probe_ops
->free
)
4518 probe_ops
->free(probe_ops
, tr
, entry
->ip
, probe
->data
);
4521 mutex_unlock(&ftrace_lock
);
4524 mutex_unlock(&probe
->ops
.func_hash
->regex_lock
);
4525 free_ftrace_hash(hash
);
4527 release_probe(probe
);
4532 mutex_unlock(&ftrace_lock
);
4536 void clear_ftrace_function_probes(struct trace_array
*tr
)
4538 struct ftrace_func_probe
*probe
, *n
;
4540 list_for_each_entry_safe(probe
, n
, &tr
->func_probes
, list
)
4541 unregister_ftrace_function_probe_func(NULL
, tr
, probe
->probe_ops
);
4544 static LIST_HEAD(ftrace_commands
);
4545 static DEFINE_MUTEX(ftrace_cmd_mutex
);
4548 * Currently we only register ftrace commands from __init, so mark this
4551 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
4553 struct ftrace_func_command
*p
;
4556 mutex_lock(&ftrace_cmd_mutex
);
4557 list_for_each_entry(p
, &ftrace_commands
, list
) {
4558 if (strcmp(cmd
->name
, p
->name
) == 0) {
4563 list_add(&cmd
->list
, &ftrace_commands
);
4565 mutex_unlock(&ftrace_cmd_mutex
);
4571 * Currently we only unregister ftrace commands from __init, so mark
4574 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
4576 struct ftrace_func_command
*p
, *n
;
4579 mutex_lock(&ftrace_cmd_mutex
);
4580 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
4581 if (strcmp(cmd
->name
, p
->name
) == 0) {
4583 list_del_init(&p
->list
);
4588 mutex_unlock(&ftrace_cmd_mutex
);
4593 static int ftrace_process_regex(struct ftrace_iterator
*iter
,
4594 char *buff
, int len
, int enable
)
4596 struct ftrace_hash
*hash
= iter
->hash
;
4597 struct trace_array
*tr
= iter
->ops
->private;
4598 char *func
, *command
, *next
= buff
;
4599 struct ftrace_func_command
*p
;
4602 func
= strsep(&next
, ":");
4605 ret
= ftrace_match_records(hash
, func
, len
);
4615 command
= strsep(&next
, ":");
4617 mutex_lock(&ftrace_cmd_mutex
);
4618 list_for_each_entry(p
, &ftrace_commands
, list
) {
4619 if (strcmp(p
->name
, command
) == 0) {
4620 ret
= p
->func(tr
, hash
, func
, command
, next
, enable
);
4625 mutex_unlock(&ftrace_cmd_mutex
);
4631 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
4632 size_t cnt
, loff_t
*ppos
, int enable
)
4634 struct ftrace_iterator
*iter
;
4635 struct trace_parser
*parser
;
4641 if (file
->f_mode
& FMODE_READ
) {
4642 struct seq_file
*m
= file
->private_data
;
4645 iter
= file
->private_data
;
4647 if (unlikely(ftrace_disabled
))
4650 /* iter->hash is a local copy, so we don't need regex_lock */
4652 parser
= &iter
->parser
;
4653 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
4655 if (read
>= 0 && trace_parser_loaded(parser
) &&
4656 !trace_parser_cont(parser
)) {
4657 ret
= ftrace_process_regex(iter
, parser
->buffer
,
4658 parser
->idx
, enable
);
4659 trace_parser_clear(parser
);
4670 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
4671 size_t cnt
, loff_t
*ppos
)
4673 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
4677 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
4678 size_t cnt
, loff_t
*ppos
)
4680 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
4684 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
4686 struct ftrace_func_entry
*entry
;
4688 if (!ftrace_location(ip
))
4692 entry
= ftrace_lookup_ip(hash
, ip
);
4695 free_hash_entry(hash
, entry
);
4699 return add_hash_entry(hash
, ip
);
4703 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4704 unsigned long ip
, int remove
, int reset
, int enable
)
4706 struct ftrace_hash
**orig_hash
;
4707 struct ftrace_hash
*hash
;
4710 if (unlikely(ftrace_disabled
))
4713 mutex_lock(&ops
->func_hash
->regex_lock
);
4716 orig_hash
= &ops
->func_hash
->filter_hash
;
4718 orig_hash
= &ops
->func_hash
->notrace_hash
;
4721 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4723 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
4727 goto out_regex_unlock
;
4730 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
4732 goto out_regex_unlock
;
4735 ret
= ftrace_match_addr(hash
, ip
, remove
);
4737 goto out_regex_unlock
;
4740 mutex_lock(&ftrace_lock
);
4741 ret
= ftrace_hash_move_and_update_ops(ops
, orig_hash
, hash
, enable
);
4742 mutex_unlock(&ftrace_lock
);
4745 mutex_unlock(&ops
->func_hash
->regex_lock
);
4747 free_ftrace_hash(hash
);
4752 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
4753 int reset
, int enable
)
4755 return ftrace_set_hash(ops
, NULL
, 0, ip
, remove
, reset
, enable
);
4759 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4760 * @ops - the ops to set the filter with
4761 * @ip - the address to add to or remove from the filter.
4762 * @remove - non zero to remove the ip from the filter
4763 * @reset - non zero to reset all filters before applying this filter.
4765 * Filters denote which functions should be enabled when tracing is enabled
4766 * If @ip is NULL, it failes to update filter.
4768 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
4769 int remove
, int reset
)
4771 ftrace_ops_init(ops
);
4772 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
4774 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
4777 * ftrace_ops_set_global_filter - setup ops to use global filters
4778 * @ops - the ops which will use the global filters
4780 * ftrace users who need global function trace filtering should call this.
4781 * It can set the global filter only if ops were not initialized before.
4783 void ftrace_ops_set_global_filter(struct ftrace_ops
*ops
)
4785 if (ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)
4788 ftrace_ops_init(ops
);
4789 ops
->func_hash
= &global_ops
.local_hash
;
4791 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter
);
4794 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
4795 int reset
, int enable
)
4797 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
4801 * ftrace_set_filter - set a function to filter on in ftrace
4802 * @ops - the ops to set the filter with
4803 * @buf - the string that holds the function filter text.
4804 * @len - the length of the string.
4805 * @reset - non zero to reset all filters before applying this filter.
4807 * Filters denote which functions should be enabled when tracing is enabled.
4808 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4810 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
4813 ftrace_ops_init(ops
);
4814 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
4816 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
4819 * ftrace_set_notrace - set a function to not trace in ftrace
4820 * @ops - the ops to set the notrace filter with
4821 * @buf - the string that holds the function notrace text.
4822 * @len - the length of the string.
4823 * @reset - non zero to reset all filters before applying this filter.
4825 * Notrace Filters denote which functions should not be enabled when tracing
4826 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4829 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
4832 ftrace_ops_init(ops
);
4833 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
4835 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
4837 * ftrace_set_global_filter - set a function to filter on with global tracers
4838 * @buf - the string that holds the function filter text.
4839 * @len - the length of the string.
4840 * @reset - non zero to reset all filters before applying this filter.
4842 * Filters denote which functions should be enabled when tracing is enabled.
4843 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4845 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
4847 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
4849 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
4852 * ftrace_set_global_notrace - set a function to not trace with global tracers
4853 * @buf - the string that holds the function notrace text.
4854 * @len - the length of the string.
4855 * @reset - non zero to reset all filters before applying this filter.
4857 * Notrace Filters denote which functions should not be enabled when tracing
4858 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4861 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
4863 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
4865 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
4868 * command line interface to allow users to set filters on boot up.
4870 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4871 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4872 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4874 /* Used by function selftest to not test if filter is set */
4875 bool ftrace_filter_param __initdata
;
4877 static int __init
set_ftrace_notrace(char *str
)
4879 ftrace_filter_param
= true;
4880 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4883 __setup("ftrace_notrace=", set_ftrace_notrace
);
4885 static int __init
set_ftrace_filter(char *str
)
4887 ftrace_filter_param
= true;
4888 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
4891 __setup("ftrace_filter=", set_ftrace_filter
);
4893 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4894 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4895 static char ftrace_graph_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
4896 static int ftrace_graph_set_hash(struct ftrace_hash
*hash
, char *buffer
);
4898 static int __init
set_graph_function(char *str
)
4900 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
4903 __setup("ftrace_graph_filter=", set_graph_function
);
4905 static int __init
set_graph_notrace_function(char *str
)
4907 strlcpy(ftrace_graph_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
4910 __setup("ftrace_graph_notrace=", set_graph_notrace_function
);
4912 static int __init
set_graph_max_depth_function(char *str
)
4916 fgraph_max_depth
= simple_strtoul(str
, NULL
, 0);
4919 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function
);
4921 static void __init
set_ftrace_early_graph(char *buf
, int enable
)
4925 struct ftrace_hash
*hash
;
4927 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
4932 func
= strsep(&buf
, ",");
4933 /* we allow only one expression at a time */
4934 ret
= ftrace_graph_set_hash(hash
, func
);
4936 printk(KERN_DEBUG
"ftrace: function %s not "
4937 "traceable\n", func
);
4941 ftrace_graph_hash
= hash
;
4943 ftrace_graph_notrace_hash
= hash
;
4945 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4948 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
4952 ftrace_ops_init(ops
);
4955 func
= strsep(&buf
, ",");
4956 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
4960 static void __init
set_ftrace_early_filters(void)
4962 if (ftrace_filter_buf
[0])
4963 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
4964 if (ftrace_notrace_buf
[0])
4965 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
4966 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4967 if (ftrace_graph_buf
[0])
4968 set_ftrace_early_graph(ftrace_graph_buf
, 1);
4969 if (ftrace_graph_notrace_buf
[0])
4970 set_ftrace_early_graph(ftrace_graph_notrace_buf
, 0);
4971 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4974 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
4976 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
4977 struct ftrace_iterator
*iter
;
4978 struct ftrace_hash
**orig_hash
;
4979 struct trace_parser
*parser
;
4983 if (file
->f_mode
& FMODE_READ
) {
4985 seq_release(inode
, file
);
4987 iter
= file
->private_data
;
4989 parser
= &iter
->parser
;
4990 if (trace_parser_loaded(parser
)) {
4991 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
4994 trace_parser_put(parser
);
4996 mutex_lock(&iter
->ops
->func_hash
->regex_lock
);
4998 if (file
->f_mode
& FMODE_WRITE
) {
4999 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
5002 orig_hash
= &iter
->ops
->func_hash
->filter_hash
;
5003 if (iter
->tr
&& !list_empty(&iter
->tr
->mod_trace
))
5004 iter
->hash
->flags
|= FTRACE_HASH_FL_MOD
;
5006 orig_hash
= &iter
->ops
->func_hash
->notrace_hash
;
5008 mutex_lock(&ftrace_lock
);
5009 ret
= ftrace_hash_move_and_update_ops(iter
->ops
, orig_hash
,
5010 iter
->hash
, filter_hash
);
5011 mutex_unlock(&ftrace_lock
);
5013 /* For read only, the hash is the ops hash */
5017 mutex_unlock(&iter
->ops
->func_hash
->regex_lock
);
5018 free_ftrace_hash(iter
->hash
);
5024 static const struct file_operations ftrace_avail_fops
= {
5025 .open
= ftrace_avail_open
,
5027 .llseek
= seq_lseek
,
5028 .release
= seq_release_private
,
5031 static const struct file_operations ftrace_enabled_fops
= {
5032 .open
= ftrace_enabled_open
,
5034 .llseek
= seq_lseek
,
5035 .release
= seq_release_private
,
5038 static const struct file_operations ftrace_filter_fops
= {
5039 .open
= ftrace_filter_open
,
5041 .write
= ftrace_filter_write
,
5042 .llseek
= tracing_lseek
,
5043 .release
= ftrace_regex_release
,
5046 static const struct file_operations ftrace_notrace_fops
= {
5047 .open
= ftrace_notrace_open
,
5049 .write
= ftrace_notrace_write
,
5050 .llseek
= tracing_lseek
,
5051 .release
= ftrace_regex_release
,
5054 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5056 static DEFINE_MUTEX(graph_lock
);
5058 struct ftrace_hash
*ftrace_graph_hash
= EMPTY_HASH
;
5059 struct ftrace_hash
*ftrace_graph_notrace_hash
= EMPTY_HASH
;
5061 enum graph_filter_type
{
5062 GRAPH_FILTER_NOTRACE
= 0,
5063 GRAPH_FILTER_FUNCTION
,
5066 #define FTRACE_GRAPH_EMPTY ((void *)1)
5068 struct ftrace_graph_data
{
5069 struct ftrace_hash
*hash
;
5070 struct ftrace_func_entry
*entry
;
5071 int idx
; /* for hash table iteration */
5072 enum graph_filter_type type
;
5073 struct ftrace_hash
*new_hash
;
5074 const struct seq_operations
*seq_ops
;
5075 struct trace_parser parser
;
5079 __g_next(struct seq_file
*m
, loff_t
*pos
)
5081 struct ftrace_graph_data
*fgd
= m
->private;
5082 struct ftrace_func_entry
*entry
= fgd
->entry
;
5083 struct hlist_head
*head
;
5084 int i
, idx
= fgd
->idx
;
5086 if (*pos
>= fgd
->hash
->count
)
5090 hlist_for_each_entry_continue(entry
, hlist
) {
5098 for (i
= idx
; i
< 1 << fgd
->hash
->size_bits
; i
++) {
5099 head
= &fgd
->hash
->buckets
[i
];
5100 hlist_for_each_entry(entry
, head
, hlist
) {
5110 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
5113 return __g_next(m
, pos
);
5116 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
5118 struct ftrace_graph_data
*fgd
= m
->private;
5120 mutex_lock(&graph_lock
);
5122 if (fgd
->type
== GRAPH_FILTER_FUNCTION
)
5123 fgd
->hash
= rcu_dereference_protected(ftrace_graph_hash
,
5124 lockdep_is_held(&graph_lock
));
5126 fgd
->hash
= rcu_dereference_protected(ftrace_graph_notrace_hash
,
5127 lockdep_is_held(&graph_lock
));
5129 /* Nothing, tell g_show to print all functions are enabled */
5130 if (ftrace_hash_empty(fgd
->hash
) && !*pos
)
5131 return FTRACE_GRAPH_EMPTY
;
5135 return __g_next(m
, pos
);
5138 static void g_stop(struct seq_file
*m
, void *p
)
5140 mutex_unlock(&graph_lock
);
5143 static int g_show(struct seq_file
*m
, void *v
)
5145 struct ftrace_func_entry
*entry
= v
;
5150 if (entry
== FTRACE_GRAPH_EMPTY
) {
5151 struct ftrace_graph_data
*fgd
= m
->private;
5153 if (fgd
->type
== GRAPH_FILTER_FUNCTION
)
5154 seq_puts(m
, "#### all functions enabled ####\n");
5156 seq_puts(m
, "#### no functions disabled ####\n");
5160 seq_printf(m
, "%ps\n", (void *)entry
->ip
);
5165 static const struct seq_operations ftrace_graph_seq_ops
= {
5173 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
5174 struct ftrace_graph_data
*fgd
)
5177 struct ftrace_hash
*new_hash
= NULL
;
5179 if (file
->f_mode
& FMODE_WRITE
) {
5180 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
5182 if (trace_parser_get_init(&fgd
->parser
, FTRACE_BUFF_MAX
))
5185 if (file
->f_flags
& O_TRUNC
)
5186 new_hash
= alloc_ftrace_hash(size_bits
);
5188 new_hash
= alloc_and_copy_ftrace_hash(size_bits
,
5196 if (file
->f_mode
& FMODE_READ
) {
5197 ret
= seq_open(file
, &ftrace_graph_seq_ops
);
5199 struct seq_file
*m
= file
->private_data
;
5203 free_ftrace_hash(new_hash
);
5207 file
->private_data
= fgd
;
5210 if (ret
< 0 && file
->f_mode
& FMODE_WRITE
)
5211 trace_parser_put(&fgd
->parser
);
5213 fgd
->new_hash
= new_hash
;
5216 * All uses of fgd->hash must be taken with the graph_lock
5217 * held. The graph_lock is going to be released, so force
5218 * fgd->hash to be reinitialized when it is taken again.
5226 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
5228 struct ftrace_graph_data
*fgd
;
5231 if (unlikely(ftrace_disabled
))
5234 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
5238 mutex_lock(&graph_lock
);
5240 fgd
->hash
= rcu_dereference_protected(ftrace_graph_hash
,
5241 lockdep_is_held(&graph_lock
));
5242 fgd
->type
= GRAPH_FILTER_FUNCTION
;
5243 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
5245 ret
= __ftrace_graph_open(inode
, file
, fgd
);
5249 mutex_unlock(&graph_lock
);
5254 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
5256 struct ftrace_graph_data
*fgd
;
5259 if (unlikely(ftrace_disabled
))
5262 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
5266 mutex_lock(&graph_lock
);
5268 fgd
->hash
= rcu_dereference_protected(ftrace_graph_notrace_hash
,
5269 lockdep_is_held(&graph_lock
));
5270 fgd
->type
= GRAPH_FILTER_NOTRACE
;
5271 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
5273 ret
= __ftrace_graph_open(inode
, file
, fgd
);
5277 mutex_unlock(&graph_lock
);
5282 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
5284 struct ftrace_graph_data
*fgd
;
5285 struct ftrace_hash
*old_hash
, *new_hash
;
5286 struct trace_parser
*parser
;
5289 if (file
->f_mode
& FMODE_READ
) {
5290 struct seq_file
*m
= file
->private_data
;
5293 seq_release(inode
, file
);
5295 fgd
= file
->private_data
;
5299 if (file
->f_mode
& FMODE_WRITE
) {
5301 parser
= &fgd
->parser
;
5303 if (trace_parser_loaded((parser
))) {
5304 ret
= ftrace_graph_set_hash(fgd
->new_hash
,
5308 trace_parser_put(parser
);
5310 new_hash
= __ftrace_hash_move(fgd
->new_hash
);
5316 mutex_lock(&graph_lock
);
5318 if (fgd
->type
== GRAPH_FILTER_FUNCTION
) {
5319 old_hash
= rcu_dereference_protected(ftrace_graph_hash
,
5320 lockdep_is_held(&graph_lock
));
5321 rcu_assign_pointer(ftrace_graph_hash
, new_hash
);
5323 old_hash
= rcu_dereference_protected(ftrace_graph_notrace_hash
,
5324 lockdep_is_held(&graph_lock
));
5325 rcu_assign_pointer(ftrace_graph_notrace_hash
, new_hash
);
5328 mutex_unlock(&graph_lock
);
5330 /* Wait till all users are no longer using the old hash */
5333 free_ftrace_hash(old_hash
);
5337 free_ftrace_hash(fgd
->new_hash
);
5344 ftrace_graph_set_hash(struct ftrace_hash
*hash
, char *buffer
)
5346 struct ftrace_glob func_g
;
5347 struct dyn_ftrace
*rec
;
5348 struct ftrace_page
*pg
;
5349 struct ftrace_func_entry
*entry
;
5354 func_g
.type
= filter_parse_regex(buffer
, strlen(buffer
),
5355 &func_g
.search
, ¬);
5357 func_g
.len
= strlen(func_g
.search
);
5359 mutex_lock(&ftrace_lock
);
5361 if (unlikely(ftrace_disabled
)) {
5362 mutex_unlock(&ftrace_lock
);
5366 do_for_each_ftrace_rec(pg
, rec
) {
5368 if (rec
->flags
& FTRACE_FL_DISABLED
)
5371 if (ftrace_match_record(rec
, &func_g
, NULL
, 0)) {
5372 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
5379 if (add_hash_entry(hash
, rec
->ip
) < 0)
5383 free_hash_entry(hash
, entry
);
5388 } while_for_each_ftrace_rec();
5390 mutex_unlock(&ftrace_lock
);
5399 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
5400 size_t cnt
, loff_t
*ppos
)
5402 ssize_t read
, ret
= 0;
5403 struct ftrace_graph_data
*fgd
= file
->private_data
;
5404 struct trace_parser
*parser
;
5409 /* Read mode uses seq functions */
5410 if (file
->f_mode
& FMODE_READ
) {
5411 struct seq_file
*m
= file
->private_data
;
5415 parser
= &fgd
->parser
;
5417 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
5419 if (read
>= 0 && trace_parser_loaded(parser
) &&
5420 !trace_parser_cont(parser
)) {
5422 ret
= ftrace_graph_set_hash(fgd
->new_hash
,
5424 trace_parser_clear(parser
);
5433 static const struct file_operations ftrace_graph_fops
= {
5434 .open
= ftrace_graph_open
,
5436 .write
= ftrace_graph_write
,
5437 .llseek
= tracing_lseek
,
5438 .release
= ftrace_graph_release
,
5441 static const struct file_operations ftrace_graph_notrace_fops
= {
5442 .open
= ftrace_graph_notrace_open
,
5444 .write
= ftrace_graph_write
,
5445 .llseek
= tracing_lseek
,
5446 .release
= ftrace_graph_release
,
5448 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5450 void ftrace_create_filter_files(struct ftrace_ops
*ops
,
5451 struct dentry
*parent
)
5454 trace_create_file("set_ftrace_filter", 0644, parent
,
5455 ops
, &ftrace_filter_fops
);
5457 trace_create_file("set_ftrace_notrace", 0644, parent
,
5458 ops
, &ftrace_notrace_fops
);
5462 * The name "destroy_filter_files" is really a misnomer. Although
5463 * in the future, it may actually delete the files, but this is
5464 * really intended to make sure the ops passed in are disabled
5465 * and that when this function returns, the caller is free to
5468 * The "destroy" name is only to match the "create" name that this
5469 * should be paired with.
5471 void ftrace_destroy_filter_files(struct ftrace_ops
*ops
)
5473 mutex_lock(&ftrace_lock
);
5474 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
)
5475 ftrace_shutdown(ops
, 0);
5476 ops
->flags
|= FTRACE_OPS_FL_DELETED
;
5477 ftrace_free_filter(ops
);
5478 mutex_unlock(&ftrace_lock
);
5481 static __init
int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
)
5484 trace_create_file("available_filter_functions", 0444,
5485 d_tracer
, NULL
, &ftrace_avail_fops
);
5487 trace_create_file("enabled_functions", 0444,
5488 d_tracer
, NULL
, &ftrace_enabled_fops
);
5490 ftrace_create_filter_files(&global_ops
, d_tracer
);
5492 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5493 trace_create_file("set_graph_function", 0644, d_tracer
,
5495 &ftrace_graph_fops
);
5496 trace_create_file("set_graph_notrace", 0644, d_tracer
,
5498 &ftrace_graph_notrace_fops
);
5499 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5504 static int ftrace_cmp_ips(const void *a
, const void *b
)
5506 const unsigned long *ipa
= a
;
5507 const unsigned long *ipb
= b
;
5516 static int ftrace_process_locs(struct module
*mod
,
5517 unsigned long *start
,
5520 struct ftrace_page
*start_pg
;
5521 struct ftrace_page
*pg
;
5522 struct dyn_ftrace
*rec
;
5523 unsigned long count
;
5526 unsigned long flags
= 0; /* Shut up gcc */
5529 count
= end
- start
;
5534 sort(start
, count
, sizeof(*start
),
5535 ftrace_cmp_ips
, NULL
);
5537 start_pg
= ftrace_allocate_pages(count
);
5541 mutex_lock(&ftrace_lock
);
5544 * Core and each module needs their own pages, as
5545 * modules will free them when they are removed.
5546 * Force a new page to be allocated for modules.
5549 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
5550 /* First initialization */
5551 ftrace_pages
= ftrace_pages_start
= start_pg
;
5556 if (WARN_ON(ftrace_pages
->next
)) {
5557 /* Hmm, we have free pages? */
5558 while (ftrace_pages
->next
)
5559 ftrace_pages
= ftrace_pages
->next
;
5562 ftrace_pages
->next
= start_pg
;
5568 addr
= ftrace_call_adjust(*p
++);
5570 * Some architecture linkers will pad between
5571 * the different mcount_loc sections of different
5572 * object files to satisfy alignments.
5573 * Skip any NULL pointers.
5578 if (pg
->index
== pg
->size
) {
5579 /* We should have allocated enough */
5580 if (WARN_ON(!pg
->next
))
5585 rec
= &pg
->records
[pg
->index
++];
5589 /* We should have used all pages */
5592 /* Assign the last page to ftrace_pages */
5596 * We only need to disable interrupts on start up
5597 * because we are modifying code that an interrupt
5598 * may execute, and the modification is not atomic.
5599 * But for modules, nothing runs the code we modify
5600 * until we are finished with it, and there's no
5601 * reason to cause large interrupt latencies while we do it.
5604 local_irq_save(flags
);
5605 ftrace_update_code(mod
, start_pg
);
5607 local_irq_restore(flags
);
5610 mutex_unlock(&ftrace_lock
);
5615 struct ftrace_mod_func
{
5616 struct list_head list
;
5622 struct ftrace_mod_map
{
5623 struct rcu_head rcu
;
5624 struct list_head list
;
5626 unsigned long start_addr
;
5627 unsigned long end_addr
;
5628 struct list_head funcs
;
5629 unsigned int num_funcs
;
5632 #ifdef CONFIG_MODULES
5634 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5636 static LIST_HEAD(ftrace_mod_maps
);
5638 static int referenced_filters(struct dyn_ftrace
*rec
)
5640 struct ftrace_ops
*ops
;
5643 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
5644 if (ops_references_rec(ops
, rec
))
5652 clear_mod_from_hash(struct ftrace_page
*pg
, struct ftrace_hash
*hash
)
5654 struct ftrace_func_entry
*entry
;
5655 struct dyn_ftrace
*rec
;
5658 if (ftrace_hash_empty(hash
))
5661 for (i
= 0; i
< pg
->index
; i
++) {
5662 rec
= &pg
->records
[i
];
5663 entry
= __ftrace_lookup_ip(hash
, rec
->ip
);
5665 * Do not allow this rec to match again.
5666 * Yeah, it may waste some memory, but will be removed
5667 * if/when the hash is modified again.
5674 /* Clear any records from hashs */
5675 static void clear_mod_from_hashes(struct ftrace_page
*pg
)
5677 struct trace_array
*tr
;
5679 mutex_lock(&trace_types_lock
);
5680 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
) {
5681 if (!tr
->ops
|| !tr
->ops
->func_hash
)
5683 mutex_lock(&tr
->ops
->func_hash
->regex_lock
);
5684 clear_mod_from_hash(pg
, tr
->ops
->func_hash
->filter_hash
);
5685 clear_mod_from_hash(pg
, tr
->ops
->func_hash
->notrace_hash
);
5686 mutex_unlock(&tr
->ops
->func_hash
->regex_lock
);
5688 mutex_unlock(&trace_types_lock
);
5691 static void ftrace_free_mod_map(struct rcu_head
*rcu
)
5693 struct ftrace_mod_map
*mod_map
= container_of(rcu
, struct ftrace_mod_map
, rcu
);
5694 struct ftrace_mod_func
*mod_func
;
5695 struct ftrace_mod_func
*n
;
5697 /* All the contents of mod_map are now not visible to readers */
5698 list_for_each_entry_safe(mod_func
, n
, &mod_map
->funcs
, list
) {
5699 kfree(mod_func
->name
);
5700 list_del(&mod_func
->list
);
5707 void ftrace_release_mod(struct module
*mod
)
5709 struct ftrace_mod_map
*mod_map
;
5710 struct ftrace_mod_map
*n
;
5711 struct dyn_ftrace
*rec
;
5712 struct ftrace_page
**last_pg
;
5713 struct ftrace_page
*tmp_page
= NULL
;
5714 struct ftrace_page
*pg
;
5717 mutex_lock(&ftrace_lock
);
5719 if (ftrace_disabled
)
5722 list_for_each_entry_safe(mod_map
, n
, &ftrace_mod_maps
, list
) {
5723 if (mod_map
->mod
== mod
) {
5724 list_del_rcu(&mod_map
->list
);
5725 call_rcu(&mod_map
->rcu
, ftrace_free_mod_map
);
5731 * Each module has its own ftrace_pages, remove
5732 * them from the list.
5734 last_pg
= &ftrace_pages_start
;
5735 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
5736 rec
= &pg
->records
[0];
5737 if (within_module_core(rec
->ip
, mod
) ||
5738 within_module_init(rec
->ip
, mod
)) {
5740 * As core pages are first, the first
5741 * page should never be a module page.
5743 if (WARN_ON(pg
== ftrace_pages_start
))
5746 /* Check if we are deleting the last page */
5747 if (pg
== ftrace_pages
)
5748 ftrace_pages
= next_to_ftrace_page(last_pg
);
5750 ftrace_update_tot_cnt
-= pg
->index
;
5751 *last_pg
= pg
->next
;
5753 pg
->next
= tmp_page
;
5756 last_pg
= &pg
->next
;
5759 mutex_unlock(&ftrace_lock
);
5761 for (pg
= tmp_page
; pg
; pg
= tmp_page
) {
5763 /* Needs to be called outside of ftrace_lock */
5764 clear_mod_from_hashes(pg
);
5766 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
5767 free_pages((unsigned long)pg
->records
, order
);
5768 tmp_page
= pg
->next
;
5773 void ftrace_module_enable(struct module
*mod
)
5775 struct dyn_ftrace
*rec
;
5776 struct ftrace_page
*pg
;
5778 mutex_lock(&ftrace_lock
);
5780 if (ftrace_disabled
)
5784 * If the tracing is enabled, go ahead and enable the record.
5786 * The reason not to enable the record immediately is the
5787 * inherent check of ftrace_make_nop/ftrace_make_call for
5788 * correct previous instructions. Making first the NOP
5789 * conversion puts the module to the correct state, thus
5790 * passing the ftrace_make_call check.
5792 * We also delay this to after the module code already set the
5793 * text to read-only, as we now need to set it back to read-write
5794 * so that we can modify the text.
5796 if (ftrace_start_up
)
5797 ftrace_arch_code_modify_prepare();
5799 do_for_each_ftrace_rec(pg
, rec
) {
5802 * do_for_each_ftrace_rec() is a double loop.
5803 * module text shares the pg. If a record is
5804 * not part of this module, then skip this pg,
5805 * which the "break" will do.
5807 if (!within_module_core(rec
->ip
, mod
) &&
5808 !within_module_init(rec
->ip
, mod
))
5814 * When adding a module, we need to check if tracers are
5815 * currently enabled and if they are, and can trace this record,
5816 * we need to enable the module functions as well as update the
5817 * reference counts for those function records.
5819 if (ftrace_start_up
)
5820 cnt
+= referenced_filters(rec
);
5822 /* This clears FTRACE_FL_DISABLED */
5825 if (ftrace_start_up
&& cnt
) {
5826 int failed
= __ftrace_replace_code(rec
, 1);
5828 ftrace_bug(failed
, rec
);
5833 } while_for_each_ftrace_rec();
5836 if (ftrace_start_up
)
5837 ftrace_arch_code_modify_post_process();
5840 mutex_unlock(&ftrace_lock
);
5842 process_cached_mods(mod
->name
);
5845 void ftrace_module_init(struct module
*mod
)
5847 if (ftrace_disabled
|| !mod
->num_ftrace_callsites
)
5850 ftrace_process_locs(mod
, mod
->ftrace_callsites
,
5851 mod
->ftrace_callsites
+ mod
->num_ftrace_callsites
);
5854 static void save_ftrace_mod_rec(struct ftrace_mod_map
*mod_map
,
5855 struct dyn_ftrace
*rec
)
5857 struct ftrace_mod_func
*mod_func
;
5858 unsigned long symsize
;
5859 unsigned long offset
;
5860 char str
[KSYM_SYMBOL_LEN
];
5864 ret
= kallsyms_lookup(rec
->ip
, &symsize
, &offset
, &modname
, str
);
5868 mod_func
= kmalloc(sizeof(*mod_func
), GFP_KERNEL
);
5872 mod_func
->name
= kstrdup(str
, GFP_KERNEL
);
5873 if (!mod_func
->name
) {
5878 mod_func
->ip
= rec
->ip
- offset
;
5879 mod_func
->size
= symsize
;
5881 mod_map
->num_funcs
++;
5883 list_add_rcu(&mod_func
->list
, &mod_map
->funcs
);
5886 static struct ftrace_mod_map
*
5887 allocate_ftrace_mod_map(struct module
*mod
,
5888 unsigned long start
, unsigned long end
)
5890 struct ftrace_mod_map
*mod_map
;
5892 mod_map
= kmalloc(sizeof(*mod_map
), GFP_KERNEL
);
5897 mod_map
->start_addr
= start
;
5898 mod_map
->end_addr
= end
;
5899 mod_map
->num_funcs
= 0;
5901 INIT_LIST_HEAD_RCU(&mod_map
->funcs
);
5903 list_add_rcu(&mod_map
->list
, &ftrace_mod_maps
);
5909 ftrace_func_address_lookup(struct ftrace_mod_map
*mod_map
,
5910 unsigned long addr
, unsigned long *size
,
5911 unsigned long *off
, char *sym
)
5913 struct ftrace_mod_func
*found_func
= NULL
;
5914 struct ftrace_mod_func
*mod_func
;
5916 list_for_each_entry_rcu(mod_func
, &mod_map
->funcs
, list
) {
5917 if (addr
>= mod_func
->ip
&&
5918 addr
< mod_func
->ip
+ mod_func
->size
) {
5919 found_func
= mod_func
;
5926 *size
= found_func
->size
;
5928 *off
= addr
- found_func
->ip
;
5930 strlcpy(sym
, found_func
->name
, KSYM_NAME_LEN
);
5932 return found_func
->name
;
5939 ftrace_mod_address_lookup(unsigned long addr
, unsigned long *size
,
5940 unsigned long *off
, char **modname
, char *sym
)
5942 struct ftrace_mod_map
*mod_map
;
5943 const char *ret
= NULL
;
5945 /* mod_map is freed via call_rcu() */
5947 list_for_each_entry_rcu(mod_map
, &ftrace_mod_maps
, list
) {
5948 ret
= ftrace_func_address_lookup(mod_map
, addr
, size
, off
, sym
);
5951 *modname
= mod_map
->mod
->name
;
5960 int ftrace_mod_get_kallsym(unsigned int symnum
, unsigned long *value
,
5961 char *type
, char *name
,
5962 char *module_name
, int *exported
)
5964 struct ftrace_mod_map
*mod_map
;
5965 struct ftrace_mod_func
*mod_func
;
5968 list_for_each_entry_rcu(mod_map
, &ftrace_mod_maps
, list
) {
5970 if (symnum
>= mod_map
->num_funcs
) {
5971 symnum
-= mod_map
->num_funcs
;
5975 list_for_each_entry_rcu(mod_func
, &mod_map
->funcs
, list
) {
5981 *value
= mod_func
->ip
;
5983 strlcpy(name
, mod_func
->name
, KSYM_NAME_LEN
);
5984 strlcpy(module_name
, mod_map
->mod
->name
, MODULE_NAME_LEN
);
5997 static void save_ftrace_mod_rec(struct ftrace_mod_map
*mod_map
,
5998 struct dyn_ftrace
*rec
) { }
5999 static inline struct ftrace_mod_map
*
6000 allocate_ftrace_mod_map(struct module
*mod
,
6001 unsigned long start
, unsigned long end
)
6005 #endif /* CONFIG_MODULES */
6007 struct ftrace_init_func
{
6008 struct list_head list
;
6012 /* Clear any init ips from hashes */
6014 clear_func_from_hash(struct ftrace_init_func
*func
, struct ftrace_hash
*hash
)
6016 struct ftrace_func_entry
*entry
;
6018 if (ftrace_hash_empty(hash
))
6021 entry
= __ftrace_lookup_ip(hash
, func
->ip
);
6024 * Do not allow this rec to match again.
6025 * Yeah, it may waste some memory, but will be removed
6026 * if/when the hash is modified again.
6033 clear_func_from_hashes(struct ftrace_init_func
*func
)
6035 struct trace_array
*tr
;
6037 mutex_lock(&trace_types_lock
);
6038 list_for_each_entry(tr
, &ftrace_trace_arrays
, list
) {
6039 if (!tr
->ops
|| !tr
->ops
->func_hash
)
6041 mutex_lock(&tr
->ops
->func_hash
->regex_lock
);
6042 clear_func_from_hash(func
, tr
->ops
->func_hash
->filter_hash
);
6043 clear_func_from_hash(func
, tr
->ops
->func_hash
->notrace_hash
);
6044 mutex_unlock(&tr
->ops
->func_hash
->regex_lock
);
6046 mutex_unlock(&trace_types_lock
);
6049 static void add_to_clear_hash_list(struct list_head
*clear_list
,
6050 struct dyn_ftrace
*rec
)
6052 struct ftrace_init_func
*func
;
6054 func
= kmalloc(sizeof(*func
), GFP_KERNEL
);
6056 WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
6061 list_add(&func
->list
, clear_list
);
6064 void ftrace_free_mem(struct module
*mod
, void *start_ptr
, void *end_ptr
)
6066 unsigned long start
= (unsigned long)(start_ptr
);
6067 unsigned long end
= (unsigned long)(end_ptr
);
6068 struct ftrace_page
**last_pg
= &ftrace_pages_start
;
6069 struct ftrace_page
*pg
;
6070 struct dyn_ftrace
*rec
;
6071 struct dyn_ftrace key
;
6072 struct ftrace_mod_map
*mod_map
= NULL
;
6073 struct ftrace_init_func
*func
, *func_next
;
6074 struct list_head clear_hash
;
6077 INIT_LIST_HEAD(&clear_hash
);
6080 key
.flags
= end
; /* overload flags, as it is unsigned long */
6082 mutex_lock(&ftrace_lock
);
6085 * If we are freeing module init memory, then check if
6086 * any tracer is active. If so, we need to save a mapping of
6087 * the module functions being freed with the address.
6089 if (mod
&& ftrace_ops_list
!= &ftrace_list_end
)
6090 mod_map
= allocate_ftrace_mod_map(mod
, start
, end
);
6092 for (pg
= ftrace_pages_start
; pg
; last_pg
= &pg
->next
, pg
= *last_pg
) {
6093 if (end
< pg
->records
[0].ip
||
6094 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
6097 rec
= bsearch(&key
, pg
->records
, pg
->index
,
6098 sizeof(struct dyn_ftrace
),
6103 /* rec will be cleared from hashes after ftrace_lock unlock */
6104 add_to_clear_hash_list(&clear_hash
, rec
);
6107 save_ftrace_mod_rec(mod_map
, rec
);
6110 ftrace_update_tot_cnt
--;
6112 *last_pg
= pg
->next
;
6113 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
6114 free_pages((unsigned long)pg
->records
, order
);
6116 pg
= container_of(last_pg
, struct ftrace_page
, next
);
6121 memmove(rec
, rec
+ 1,
6122 (pg
->index
- (rec
- pg
->records
)) * sizeof(*rec
));
6123 /* More than one function may be in this block */
6126 mutex_unlock(&ftrace_lock
);
6128 list_for_each_entry_safe(func
, func_next
, &clear_hash
, list
) {
6129 clear_func_from_hashes(func
);
6134 void __init
ftrace_free_init_mem(void)
6136 void *start
= (void *)(&__init_begin
);
6137 void *end
= (void *)(&__init_end
);
6139 ftrace_free_mem(NULL
, start
, end
);
6142 void __init
ftrace_init(void)
6144 extern unsigned long __start_mcount_loc
[];
6145 extern unsigned long __stop_mcount_loc
[];
6146 unsigned long count
, flags
;
6149 local_irq_save(flags
);
6150 ret
= ftrace_dyn_arch_init();
6151 local_irq_restore(flags
);
6155 count
= __stop_mcount_loc
- __start_mcount_loc
;
6157 pr_info("ftrace: No functions to be traced?\n");
6161 pr_info("ftrace: allocating %ld entries in %ld pages\n",
6162 count
, count
/ ENTRIES_PER_PAGE
+ 1);
6164 last_ftrace_enabled
= ftrace_enabled
= 1;
6166 ret
= ftrace_process_locs(NULL
,
6170 set_ftrace_early_filters();
6174 ftrace_disabled
= 1;
6177 /* Do nothing if arch does not support this */
6178 void __weak
arch_ftrace_update_trampoline(struct ftrace_ops
*ops
)
6182 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
6184 arch_ftrace_update_trampoline(ops
);
6187 void ftrace_init_trace_array(struct trace_array
*tr
)
6189 INIT_LIST_HEAD(&tr
->func_probes
);
6190 INIT_LIST_HEAD(&tr
->mod_trace
);
6191 INIT_LIST_HEAD(&tr
->mod_notrace
);
6195 struct ftrace_ops global_ops
= {
6196 .func
= ftrace_stub
,
6197 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
6198 FTRACE_OPS_FL_INITIALIZED
|
6202 static int __init
ftrace_nodyn_init(void)
6207 core_initcall(ftrace_nodyn_init
);
6209 static inline int ftrace_init_dyn_tracefs(struct dentry
*d_tracer
) { return 0; }
6210 static inline void ftrace_startup_enable(int command
) { }
6211 static inline void ftrace_startup_all(int command
) { }
6213 # define ftrace_startup_sysctl() do { } while (0)
6214 # define ftrace_shutdown_sysctl() do { } while (0)
6216 static void ftrace_update_trampoline(struct ftrace_ops
*ops
)
6220 #endif /* CONFIG_DYNAMIC_FTRACE */
6222 __init
void ftrace_init_global_array_ops(struct trace_array
*tr
)
6224 tr
->ops
= &global_ops
;
6225 tr
->ops
->private = tr
;
6226 ftrace_init_trace_array(tr
);
6229 void ftrace_init_array_ops(struct trace_array
*tr
, ftrace_func_t func
)
6231 /* If we filter on pids, update to use the pid function */
6232 if (tr
->flags
& TRACE_ARRAY_FL_GLOBAL
) {
6233 if (WARN_ON(tr
->ops
->func
!= ftrace_stub
))
6234 printk("ftrace ops had %pS for function\n",
6237 tr
->ops
->func
= func
;
6238 tr
->ops
->private = tr
;
6241 void ftrace_reset_array_ops(struct trace_array
*tr
)
6243 tr
->ops
->func
= ftrace_stub
;
6246 static nokprobe_inline
void
6247 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
6248 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
6250 struct ftrace_ops
*op
;
6253 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
6258 * Some of the ops may be dynamically allocated,
6259 * they must be freed after a synchronize_rcu().
6261 preempt_disable_notrace();
6263 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
6264 /* Stub functions don't need to be called nor tested */
6265 if (op
->flags
& FTRACE_OPS_FL_STUB
)
6268 * Check the following for each ops before calling their func:
6269 * if RCU flag is set, then rcu_is_watching() must be true
6270 * if PER_CPU is set, then ftrace_function_local_disable()
6272 * Otherwise test if the ip matches the ops filter
6274 * If any of the above fails then the op->func() is not executed.
6276 if ((!(op
->flags
& FTRACE_OPS_FL_RCU
) || rcu_is_watching()) &&
6277 ftrace_ops_test(op
, ip
, regs
)) {
6278 if (FTRACE_WARN_ON(!op
->func
)) {
6279 pr_warn("op=%p %pS\n", op
, op
);
6282 op
->func(ip
, parent_ip
, op
, regs
);
6284 } while_for_each_ftrace_op(op
);
6286 preempt_enable_notrace();
6287 trace_clear_recursion(bit
);
6291 * Some archs only support passing ip and parent_ip. Even though
6292 * the list function ignores the op parameter, we do not want any
6293 * C side effects, where a function is called without the caller
6294 * sending a third parameter.
6295 * Archs are to support both the regs and ftrace_ops at the same time.
6296 * If they support ftrace_ops, it is assumed they support regs.
6297 * If call backs want to use regs, they must either check for regs
6298 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6299 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6300 * An architecture can pass partial regs with ftrace_ops and still
6301 * set the ARCH_SUPPORTS_FTRACE_OPS.
6303 #if ARCH_SUPPORTS_FTRACE_OPS
6304 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
6305 struct ftrace_ops
*op
, struct pt_regs
*regs
)
6307 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
6309 NOKPROBE_SYMBOL(ftrace_ops_list_func
);
6311 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
6313 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
6315 NOKPROBE_SYMBOL(ftrace_ops_no_ops
);
6319 * If there's only one function registered but it does not support
6320 * recursion, needs RCU protection and/or requires per cpu handling, then
6321 * this function will be called by the mcount trampoline.
6323 static void ftrace_ops_assist_func(unsigned long ip
, unsigned long parent_ip
,
6324 struct ftrace_ops
*op
, struct pt_regs
*regs
)
6328 if ((op
->flags
& FTRACE_OPS_FL_RCU
) && !rcu_is_watching())
6331 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
6335 preempt_disable_notrace();
6337 op
->func(ip
, parent_ip
, op
, regs
);
6339 preempt_enable_notrace();
6340 trace_clear_recursion(bit
);
6342 NOKPROBE_SYMBOL(ftrace_ops_assist_func
);
6345 * ftrace_ops_get_func - get the function a trampoline should call
6346 * @ops: the ops to get the function for
6348 * Normally the mcount trampoline will call the ops->func, but there
6349 * are times that it should not. For example, if the ops does not
6350 * have its own recursion protection, then it should call the
6351 * ftrace_ops_assist_func() instead.
6353 * Returns the function that the trampoline should call for @ops.
6355 ftrace_func_t
ftrace_ops_get_func(struct ftrace_ops
*ops
)
6358 * If the function does not handle recursion, needs to be RCU safe,
6359 * or does per cpu logic, then we need to call the assist handler.
6361 if (!(ops
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) ||
6362 ops
->flags
& FTRACE_OPS_FL_RCU
)
6363 return ftrace_ops_assist_func
;
6369 ftrace_filter_pid_sched_switch_probe(void *data
, bool preempt
,
6370 struct task_struct
*prev
, struct task_struct
*next
)
6372 struct trace_array
*tr
= data
;
6373 struct trace_pid_list
*pid_list
;
6375 pid_list
= rcu_dereference_sched(tr
->function_pids
);
6377 this_cpu_write(tr
->trace_buffer
.data
->ftrace_ignore_pid
,
6378 trace_ignore_this_task(pid_list
, next
));
6382 ftrace_pid_follow_sched_process_fork(void *data
,
6383 struct task_struct
*self
,
6384 struct task_struct
*task
)
6386 struct trace_pid_list
*pid_list
;
6387 struct trace_array
*tr
= data
;
6389 pid_list
= rcu_dereference_sched(tr
->function_pids
);
6390 trace_filter_add_remove_task(pid_list
, self
, task
);
6394 ftrace_pid_follow_sched_process_exit(void *data
, struct task_struct
*task
)
6396 struct trace_pid_list
*pid_list
;
6397 struct trace_array
*tr
= data
;
6399 pid_list
= rcu_dereference_sched(tr
->function_pids
);
6400 trace_filter_add_remove_task(pid_list
, NULL
, task
);
6403 void ftrace_pid_follow_fork(struct trace_array
*tr
, bool enable
)
6406 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork
,
6408 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit
,
6411 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork
,
6413 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit
,
6418 static void clear_ftrace_pids(struct trace_array
*tr
)
6420 struct trace_pid_list
*pid_list
;
6423 pid_list
= rcu_dereference_protected(tr
->function_pids
,
6424 lockdep_is_held(&ftrace_lock
));
6428 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe
, tr
);
6430 for_each_possible_cpu(cpu
)
6431 per_cpu_ptr(tr
->trace_buffer
.data
, cpu
)->ftrace_ignore_pid
= false;
6433 rcu_assign_pointer(tr
->function_pids
, NULL
);
6435 /* Wait till all users are no longer using pid filtering */
6438 trace_free_pid_list(pid_list
);
6441 void ftrace_clear_pids(struct trace_array
*tr
)
6443 mutex_lock(&ftrace_lock
);
6445 clear_ftrace_pids(tr
);
6447 mutex_unlock(&ftrace_lock
);
6450 static void ftrace_pid_reset(struct trace_array
*tr
)
6452 mutex_lock(&ftrace_lock
);
6453 clear_ftrace_pids(tr
);
6455 ftrace_update_pid_func();
6456 ftrace_startup_all(0);
6458 mutex_unlock(&ftrace_lock
);
6461 /* Greater than any max PID */
6462 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
6464 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
6467 struct trace_pid_list
*pid_list
;
6468 struct trace_array
*tr
= m
->private;
6470 mutex_lock(&ftrace_lock
);
6471 rcu_read_lock_sched();
6473 pid_list
= rcu_dereference_sched(tr
->function_pids
);
6476 return !(*pos
) ? FTRACE_NO_PIDS
: NULL
;
6478 return trace_pid_start(pid_list
, pos
);
6481 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
6483 struct trace_array
*tr
= m
->private;
6484 struct trace_pid_list
*pid_list
= rcu_dereference_sched(tr
->function_pids
);
6486 if (v
== FTRACE_NO_PIDS
)
6489 return trace_pid_next(pid_list
, v
, pos
);
6492 static void fpid_stop(struct seq_file
*m
, void *p
)
6495 rcu_read_unlock_sched();
6496 mutex_unlock(&ftrace_lock
);
6499 static int fpid_show(struct seq_file
*m
, void *v
)
6501 if (v
== FTRACE_NO_PIDS
) {
6502 seq_puts(m
, "no pid\n");
6506 return trace_pid_show(m
, v
);
6509 static const struct seq_operations ftrace_pid_sops
= {
6510 .start
= fpid_start
,
6517 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
6519 struct trace_array
*tr
= inode
->i_private
;
6523 if (trace_array_get(tr
) < 0)
6526 if ((file
->f_mode
& FMODE_WRITE
) &&
6527 (file
->f_flags
& O_TRUNC
))
6528 ftrace_pid_reset(tr
);
6530 ret
= seq_open(file
, &ftrace_pid_sops
);
6532 trace_array_put(tr
);
6534 m
= file
->private_data
;
6535 /* copy tr over to seq ops */
6542 static void ignore_task_cpu(void *data
)
6544 struct trace_array
*tr
= data
;
6545 struct trace_pid_list
*pid_list
;
6548 * This function is called by on_each_cpu() while the
6549 * event_mutex is held.
6551 pid_list
= rcu_dereference_protected(tr
->function_pids
,
6552 mutex_is_locked(&ftrace_lock
));
6554 this_cpu_write(tr
->trace_buffer
.data
->ftrace_ignore_pid
,
6555 trace_ignore_this_task(pid_list
, current
));
6559 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
6560 size_t cnt
, loff_t
*ppos
)
6562 struct seq_file
*m
= filp
->private_data
;
6563 struct trace_array
*tr
= m
->private;
6564 struct trace_pid_list
*filtered_pids
= NULL
;
6565 struct trace_pid_list
*pid_list
;
6571 mutex_lock(&ftrace_lock
);
6573 filtered_pids
= rcu_dereference_protected(tr
->function_pids
,
6574 lockdep_is_held(&ftrace_lock
));
6576 ret
= trace_pid_write(filtered_pids
, &pid_list
, ubuf
, cnt
);
6580 rcu_assign_pointer(tr
->function_pids
, pid_list
);
6582 if (filtered_pids
) {
6584 trace_free_pid_list(filtered_pids
);
6585 } else if (pid_list
) {
6586 /* Register a probe to set whether to ignore the tracing of a task */
6587 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe
, tr
);
6591 * Ignoring of pids is done at task switch. But we have to
6592 * check for those tasks that are currently running.
6593 * Always do this in case a pid was appended or removed.
6595 on_each_cpu(ignore_task_cpu
, tr
, 1);
6597 ftrace_update_pid_func();
6598 ftrace_startup_all(0);
6600 mutex_unlock(&ftrace_lock
);
6609 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
6611 struct trace_array
*tr
= inode
->i_private
;
6613 trace_array_put(tr
);
6615 return seq_release(inode
, file
);
6618 static const struct file_operations ftrace_pid_fops
= {
6619 .open
= ftrace_pid_open
,
6620 .write
= ftrace_pid_write
,
6622 .llseek
= tracing_lseek
,
6623 .release
= ftrace_pid_release
,
6626 void ftrace_init_tracefs(struct trace_array
*tr
, struct dentry
*d_tracer
)
6628 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
6629 tr
, &ftrace_pid_fops
);
6632 void __init
ftrace_init_tracefs_toplevel(struct trace_array
*tr
,
6633 struct dentry
*d_tracer
)
6635 /* Only the top level directory has the dyn_tracefs and profile */
6636 WARN_ON(!(tr
->flags
& TRACE_ARRAY_FL_GLOBAL
));
6638 ftrace_init_dyn_tracefs(d_tracer
);
6639 ftrace_profile_tracefs(d_tracer
);
6643 * ftrace_kill - kill ftrace
6645 * This function should be used by panic code. It stops ftrace
6646 * but in a not so nice way. If you need to simply kill ftrace
6647 * from a non-atomic section, use ftrace_kill.
6649 void ftrace_kill(void)
6651 ftrace_disabled
= 1;
6653 ftrace_trace_function
= ftrace_stub
;
6657 * Test if ftrace is dead or not.
6659 int ftrace_is_dead(void)
6661 return ftrace_disabled
;
6665 * register_ftrace_function - register a function for profiling
6666 * @ops - ops structure that holds the function for profiling.
6668 * Register a function to be called by all functions in the
6671 * Note: @ops->func and all the functions it calls must be labeled
6672 * with "notrace", otherwise it will go into a
6675 int register_ftrace_function(struct ftrace_ops
*ops
)
6679 ftrace_ops_init(ops
);
6681 mutex_lock(&ftrace_lock
);
6683 ret
= ftrace_startup(ops
, 0);
6685 mutex_unlock(&ftrace_lock
);
6689 EXPORT_SYMBOL_GPL(register_ftrace_function
);
6692 * unregister_ftrace_function - unregister a function for profiling.
6693 * @ops - ops structure that holds the function to unregister
6695 * Unregister a function that was added to be called by ftrace profiling.
6697 int unregister_ftrace_function(struct ftrace_ops
*ops
)
6701 mutex_lock(&ftrace_lock
);
6702 ret
= ftrace_shutdown(ops
, 0);
6703 mutex_unlock(&ftrace_lock
);
6707 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
6710 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
6711 void __user
*buffer
, size_t *lenp
,
6716 mutex_lock(&ftrace_lock
);
6718 if (unlikely(ftrace_disabled
))
6721 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
6723 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
6726 last_ftrace_enabled
= !!ftrace_enabled
;
6728 if (ftrace_enabled
) {
6730 /* we are starting ftrace again */
6731 if (rcu_dereference_protected(ftrace_ops_list
,
6732 lockdep_is_held(&ftrace_lock
)) != &ftrace_list_end
)
6733 update_ftrace_function();
6735 ftrace_startup_sysctl();
6738 /* stopping ftrace calls (just send to ftrace_stub) */
6739 ftrace_trace_function
= ftrace_stub
;
6741 ftrace_shutdown_sysctl();
6745 mutex_unlock(&ftrace_lock
);