2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 Nadia Yvette Chambers
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/kallsyms.h>
19 #include <linux/seq_file.h>
20 #include <linux/suspend.h>
21 #include <linux/debugfs.h>
22 #include <linux/hardirq.h>
23 #include <linux/kthread.h>
24 #include <linux/uaccess.h>
25 #include <linux/bsearch.h>
26 #include <linux/module.h>
27 #include <linux/ftrace.h>
28 #include <linux/sysctl.h>
29 #include <linux/slab.h>
30 #include <linux/ctype.h>
31 #include <linux/sort.h>
32 #include <linux/list.h>
33 #include <linux/hash.h>
34 #include <linux/rcupdate.h>
36 #include <trace/events/sched.h>
38 #include <asm/setup.h>
40 #include "trace_output.h"
41 #include "trace_stat.h"
43 #define FTRACE_WARN_ON(cond) \
51 #define FTRACE_WARN_ON_ONCE(cond) \
54 if (WARN_ON_ONCE(___r)) \
59 /* hash bits for specific function selection */
60 #define FTRACE_HASH_BITS 7
61 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
62 #define FTRACE_HASH_DEFAULT_BITS 10
63 #define FTRACE_HASH_MAX_BITS 12
65 #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL)
67 #ifdef CONFIG_DYNAMIC_FTRACE
68 #define INIT_OPS_HASH(opsname) \
69 .func_hash = &opsname.local_hash, \
70 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
71 #define ASSIGN_OPS_HASH(opsname, val) \
73 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
75 #define INIT_OPS_HASH(opsname)
76 #define ASSIGN_OPS_HASH(opsname, val)
79 static struct ftrace_ops ftrace_list_end __read_mostly
= {
81 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_STUB
,
82 INIT_OPS_HASH(ftrace_list_end
)
85 /* ftrace_enabled is a method to turn ftrace on or off */
86 int ftrace_enabled __read_mostly
;
87 static int last_ftrace_enabled
;
89 /* Current function tracing op */
90 struct ftrace_ops
*function_trace_op __read_mostly
= &ftrace_list_end
;
91 /* What to set function_trace_op to */
92 static struct ftrace_ops
*set_function_trace_op
;
94 /* List for set_ftrace_pid's pids. */
95 LIST_HEAD(ftrace_pids
);
97 struct list_head list
;
102 * ftrace_disabled is set when an anomaly is discovered.
103 * ftrace_disabled is much stronger than ftrace_enabled.
105 static int ftrace_disabled __read_mostly
;
107 static DEFINE_MUTEX(ftrace_lock
);
109 static struct ftrace_ops
*ftrace_control_list __read_mostly
= &ftrace_list_end
;
110 static struct ftrace_ops
*ftrace_ops_list __read_mostly
= &ftrace_list_end
;
111 ftrace_func_t ftrace_trace_function __read_mostly
= ftrace_stub
;
112 ftrace_func_t ftrace_pid_function __read_mostly
= ftrace_stub
;
113 static struct ftrace_ops global_ops
;
114 static struct ftrace_ops control_ops
;
116 #if ARCH_SUPPORTS_FTRACE_OPS
117 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
118 struct ftrace_ops
*op
, struct pt_regs
*regs
);
120 /* See comment below, where ftrace_ops_list_func is defined */
121 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
);
122 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
126 * Traverse the ftrace_global_list, invoking all entries. The reason that we
127 * can use rcu_dereference_raw_notrace() is that elements removed from this list
128 * are simply leaked, so there is no need to interact with a grace-period
129 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
130 * concurrent insertions into the ftrace_global_list.
132 * Silly Alpha and silly pointer-speculation compiler optimizations!
134 #define do_for_each_ftrace_op(op, list) \
135 op = rcu_dereference_raw_notrace(list); \
139 * Optimized for just a single item in the list (as that is the normal case).
141 #define while_for_each_ftrace_op(op) \
142 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
143 unlikely((op) != &ftrace_list_end))
145 static inline void ftrace_ops_init(struct ftrace_ops
*ops
)
147 #ifdef CONFIG_DYNAMIC_FTRACE
148 if (!(ops
->flags
& FTRACE_OPS_FL_INITIALIZED
)) {
149 mutex_init(&ops
->local_hash
.regex_lock
);
150 ops
->func_hash
= &ops
->local_hash
;
151 ops
->flags
|= FTRACE_OPS_FL_INITIALIZED
;
157 * ftrace_nr_registered_ops - return number of ops registered
159 * Returns the number of ftrace_ops registered and tracing functions
161 int ftrace_nr_registered_ops(void)
163 struct ftrace_ops
*ops
;
166 mutex_lock(&ftrace_lock
);
168 for (ops
= ftrace_ops_list
;
169 ops
!= &ftrace_list_end
; ops
= ops
->next
)
172 mutex_unlock(&ftrace_lock
);
177 static void ftrace_pid_func(unsigned long ip
, unsigned long parent_ip
,
178 struct ftrace_ops
*op
, struct pt_regs
*regs
)
180 if (!test_tsk_trace_trace(current
))
183 ftrace_pid_function(ip
, parent_ip
, op
, regs
);
186 static void set_ftrace_pid_function(ftrace_func_t func
)
188 /* do not set ftrace_pid_function to itself! */
189 if (func
!= ftrace_pid_func
)
190 ftrace_pid_function
= func
;
194 * clear_ftrace_function - reset the ftrace function
196 * This NULLs the ftrace function and in essence stops
197 * tracing. There may be lag
199 void clear_ftrace_function(void)
201 ftrace_trace_function
= ftrace_stub
;
202 ftrace_pid_function
= ftrace_stub
;
205 static void control_ops_disable_all(struct ftrace_ops
*ops
)
209 for_each_possible_cpu(cpu
)
210 *per_cpu_ptr(ops
->disabled
, cpu
) = 1;
213 static int control_ops_alloc(struct ftrace_ops
*ops
)
215 int __percpu
*disabled
;
217 disabled
= alloc_percpu(int);
221 ops
->disabled
= disabled
;
222 control_ops_disable_all(ops
);
226 static void ftrace_sync(struct work_struct
*work
)
229 * This function is just a stub to implement a hard force
230 * of synchronize_sched(). This requires synchronizing
231 * tasks even in userspace and idle.
233 * Yes, function tracing is rude.
237 static void ftrace_sync_ipi(void *data
)
239 /* Probably not needed, but do it anyway */
243 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
244 static void update_function_graph_func(void);
246 static inline void update_function_graph_func(void) { }
249 static void update_ftrace_function(void)
254 * If we are at the end of the list and this ops is
255 * recursion safe and not dynamic and the arch supports passing ops,
256 * then have the mcount trampoline call the function directly.
258 if (ftrace_ops_list
== &ftrace_list_end
||
259 (ftrace_ops_list
->next
== &ftrace_list_end
&&
260 !(ftrace_ops_list
->flags
& FTRACE_OPS_FL_DYNAMIC
) &&
261 (ftrace_ops_list
->flags
& FTRACE_OPS_FL_RECURSION_SAFE
) &&
262 !FTRACE_FORCE_LIST_FUNC
)) {
263 /* Set the ftrace_ops that the arch callback uses */
264 set_function_trace_op
= ftrace_ops_list
;
265 func
= ftrace_ops_list
->func
;
267 /* Just use the default ftrace_ops */
268 set_function_trace_op
= &ftrace_list_end
;
269 func
= ftrace_ops_list_func
;
272 update_function_graph_func();
274 /* If there's no change, then do nothing more here */
275 if (ftrace_trace_function
== func
)
279 * If we are using the list function, it doesn't care
280 * about the function_trace_ops.
282 if (func
== ftrace_ops_list_func
) {
283 ftrace_trace_function
= func
;
285 * Don't even bother setting function_trace_ops,
286 * it would be racy to do so anyway.
291 #ifndef CONFIG_DYNAMIC_FTRACE
293 * For static tracing, we need to be a bit more careful.
294 * The function change takes affect immediately. Thus,
295 * we need to coorditate the setting of the function_trace_ops
296 * with the setting of the ftrace_trace_function.
298 * Set the function to the list ops, which will call the
299 * function we want, albeit indirectly, but it handles the
300 * ftrace_ops and doesn't depend on function_trace_op.
302 ftrace_trace_function
= ftrace_ops_list_func
;
304 * Make sure all CPUs see this. Yes this is slow, but static
305 * tracing is slow and nasty to have enabled.
307 schedule_on_each_cpu(ftrace_sync
);
308 /* Now all cpus are using the list ops. */
309 function_trace_op
= set_function_trace_op
;
310 /* Make sure the function_trace_op is visible on all CPUs */
312 /* Nasty way to force a rmb on all cpus */
313 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
314 /* OK, we are all set to update the ftrace_trace_function now! */
315 #endif /* !CONFIG_DYNAMIC_FTRACE */
317 ftrace_trace_function
= func
;
320 int using_ftrace_ops_list_func(void)
322 return ftrace_trace_function
== ftrace_ops_list_func
;
325 static void add_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
329 * We are entering ops into the list but another
330 * CPU might be walking that list. We need to make sure
331 * the ops->next pointer is valid before another CPU sees
332 * the ops pointer included into the list.
334 rcu_assign_pointer(*list
, ops
);
337 static int remove_ftrace_ops(struct ftrace_ops
**list
, struct ftrace_ops
*ops
)
339 struct ftrace_ops
**p
;
342 * If we are removing the last function, then simply point
343 * to the ftrace_stub.
345 if (*list
== ops
&& ops
->next
== &ftrace_list_end
) {
346 *list
= &ftrace_list_end
;
350 for (p
= list
; *p
!= &ftrace_list_end
; p
= &(*p
)->next
)
361 static void add_ftrace_list_ops(struct ftrace_ops
**list
,
362 struct ftrace_ops
*main_ops
,
363 struct ftrace_ops
*ops
)
365 int first
= *list
== &ftrace_list_end
;
366 add_ftrace_ops(list
, ops
);
368 add_ftrace_ops(&ftrace_ops_list
, main_ops
);
371 static int remove_ftrace_list_ops(struct ftrace_ops
**list
,
372 struct ftrace_ops
*main_ops
,
373 struct ftrace_ops
*ops
)
375 int ret
= remove_ftrace_ops(list
, ops
);
376 if (!ret
&& *list
== &ftrace_list_end
)
377 ret
= remove_ftrace_ops(&ftrace_ops_list
, main_ops
);
381 static int __register_ftrace_function(struct ftrace_ops
*ops
)
383 if (ops
->flags
& FTRACE_OPS_FL_DELETED
)
386 if (WARN_ON(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
389 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
391 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
392 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
393 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
395 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
&&
396 !(ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
))
399 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
)
400 ops
->flags
|= FTRACE_OPS_FL_SAVE_REGS
;
403 if (!core_kernel_data((unsigned long)ops
))
404 ops
->flags
|= FTRACE_OPS_FL_DYNAMIC
;
406 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
407 if (control_ops_alloc(ops
))
409 add_ftrace_list_ops(&ftrace_control_list
, &control_ops
, ops
);
411 add_ftrace_ops(&ftrace_ops_list
, ops
);
414 update_ftrace_function();
419 static int __unregister_ftrace_function(struct ftrace_ops
*ops
)
423 if (WARN_ON(!(ops
->flags
& FTRACE_OPS_FL_ENABLED
)))
426 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
) {
427 ret
= remove_ftrace_list_ops(&ftrace_control_list
,
430 ret
= remove_ftrace_ops(&ftrace_ops_list
, ops
);
436 update_ftrace_function();
441 static void ftrace_update_pid_func(void)
443 /* Only do something if we are tracing something */
444 if (ftrace_trace_function
== ftrace_stub
)
447 update_ftrace_function();
450 #ifdef CONFIG_FUNCTION_PROFILER
451 struct ftrace_profile
{
452 struct hlist_node node
;
454 unsigned long counter
;
455 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
456 unsigned long long time
;
457 unsigned long long time_squared
;
461 struct ftrace_profile_page
{
462 struct ftrace_profile_page
*next
;
464 struct ftrace_profile records
[];
467 struct ftrace_profile_stat
{
469 struct hlist_head
*hash
;
470 struct ftrace_profile_page
*pages
;
471 struct ftrace_profile_page
*start
;
472 struct tracer_stat stat
;
475 #define PROFILE_RECORDS_SIZE \
476 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
478 #define PROFILES_PER_PAGE \
479 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
481 static int ftrace_profile_enabled __read_mostly
;
483 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
484 static DEFINE_MUTEX(ftrace_profile_lock
);
486 static DEFINE_PER_CPU(struct ftrace_profile_stat
, ftrace_profile_stats
);
488 #define FTRACE_PROFILE_HASH_BITS 10
489 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
492 function_stat_next(void *v
, int idx
)
494 struct ftrace_profile
*rec
= v
;
495 struct ftrace_profile_page
*pg
;
497 pg
= (struct ftrace_profile_page
*)((unsigned long)rec
& PAGE_MASK
);
503 if ((void *)rec
>= (void *)&pg
->records
[pg
->index
]) {
507 rec
= &pg
->records
[0];
515 static void *function_stat_start(struct tracer_stat
*trace
)
517 struct ftrace_profile_stat
*stat
=
518 container_of(trace
, struct ftrace_profile_stat
, stat
);
520 if (!stat
|| !stat
->start
)
523 return function_stat_next(&stat
->start
->records
[0], 0);
526 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
527 /* function graph compares on total time */
528 static int function_stat_cmp(void *p1
, void *p2
)
530 struct ftrace_profile
*a
= p1
;
531 struct ftrace_profile
*b
= p2
;
533 if (a
->time
< b
->time
)
535 if (a
->time
> b
->time
)
541 /* not function graph compares against hits */
542 static int function_stat_cmp(void *p1
, void *p2
)
544 struct ftrace_profile
*a
= p1
;
545 struct ftrace_profile
*b
= p2
;
547 if (a
->counter
< b
->counter
)
549 if (a
->counter
> b
->counter
)
556 static int function_stat_headers(struct seq_file
*m
)
558 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
559 seq_printf(m
, " Function "
562 "--- ---- --- ---\n");
564 seq_printf(m
, " Function Hit\n"
570 static int function_stat_show(struct seq_file
*m
, void *v
)
572 struct ftrace_profile
*rec
= v
;
573 char str
[KSYM_SYMBOL_LEN
];
575 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
576 static struct trace_seq s
;
577 unsigned long long avg
;
578 unsigned long long stddev
;
580 mutex_lock(&ftrace_profile_lock
);
582 /* we raced with function_profile_reset() */
583 if (unlikely(rec
->counter
== 0)) {
588 kallsyms_lookup(rec
->ip
, NULL
, NULL
, NULL
, str
);
589 seq_printf(m
, " %-30.30s %10lu", str
, rec
->counter
);
591 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
594 do_div(avg
, rec
->counter
);
596 /* Sample standard deviation (s^2) */
597 if (rec
->counter
<= 1)
601 * Apply Welford's method:
602 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
604 stddev
= rec
->counter
* rec
->time_squared
-
605 rec
->time
* rec
->time
;
608 * Divide only 1000 for ns^2 -> us^2 conversion.
609 * trace_print_graph_duration will divide 1000 again.
611 do_div(stddev
, rec
->counter
* (rec
->counter
- 1) * 1000);
615 trace_print_graph_duration(rec
->time
, &s
);
616 trace_seq_puts(&s
, " ");
617 trace_print_graph_duration(avg
, &s
);
618 trace_seq_puts(&s
, " ");
619 trace_print_graph_duration(stddev
, &s
);
620 trace_print_seq(m
, &s
);
624 mutex_unlock(&ftrace_profile_lock
);
629 static void ftrace_profile_reset(struct ftrace_profile_stat
*stat
)
631 struct ftrace_profile_page
*pg
;
633 pg
= stat
->pages
= stat
->start
;
636 memset(pg
->records
, 0, PROFILE_RECORDS_SIZE
);
641 memset(stat
->hash
, 0,
642 FTRACE_PROFILE_HASH_SIZE
* sizeof(struct hlist_head
));
645 int ftrace_profile_pages_init(struct ftrace_profile_stat
*stat
)
647 struct ftrace_profile_page
*pg
;
652 /* If we already allocated, do nothing */
656 stat
->pages
= (void *)get_zeroed_page(GFP_KERNEL
);
660 #ifdef CONFIG_DYNAMIC_FTRACE
661 functions
= ftrace_update_tot_cnt
;
664 * We do not know the number of functions that exist because
665 * dynamic tracing is what counts them. With past experience
666 * we have around 20K functions. That should be more than enough.
667 * It is highly unlikely we will execute every function in
673 pg
= stat
->start
= stat
->pages
;
675 pages
= DIV_ROUND_UP(functions
, PROFILES_PER_PAGE
);
677 for (i
= 1; i
< pages
; i
++) {
678 pg
->next
= (void *)get_zeroed_page(GFP_KERNEL
);
689 unsigned long tmp
= (unsigned long)pg
;
701 static int ftrace_profile_init_cpu(int cpu
)
703 struct ftrace_profile_stat
*stat
;
706 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
709 /* If the profile is already created, simply reset it */
710 ftrace_profile_reset(stat
);
715 * We are profiling all functions, but usually only a few thousand
716 * functions are hit. We'll make a hash of 1024 items.
718 size
= FTRACE_PROFILE_HASH_SIZE
;
720 stat
->hash
= kzalloc(sizeof(struct hlist_head
) * size
, GFP_KERNEL
);
725 /* Preallocate the function profiling pages */
726 if (ftrace_profile_pages_init(stat
) < 0) {
735 static int ftrace_profile_init(void)
740 for_each_possible_cpu(cpu
) {
741 ret
= ftrace_profile_init_cpu(cpu
);
749 /* interrupts must be disabled */
750 static struct ftrace_profile
*
751 ftrace_find_profiled_func(struct ftrace_profile_stat
*stat
, unsigned long ip
)
753 struct ftrace_profile
*rec
;
754 struct hlist_head
*hhd
;
757 key
= hash_long(ip
, FTRACE_PROFILE_HASH_BITS
);
758 hhd
= &stat
->hash
[key
];
760 if (hlist_empty(hhd
))
763 hlist_for_each_entry_rcu_notrace(rec
, hhd
, node
) {
771 static void ftrace_add_profile(struct ftrace_profile_stat
*stat
,
772 struct ftrace_profile
*rec
)
776 key
= hash_long(rec
->ip
, FTRACE_PROFILE_HASH_BITS
);
777 hlist_add_head_rcu(&rec
->node
, &stat
->hash
[key
]);
781 * The memory is already allocated, this simply finds a new record to use.
783 static struct ftrace_profile
*
784 ftrace_profile_alloc(struct ftrace_profile_stat
*stat
, unsigned long ip
)
786 struct ftrace_profile
*rec
= NULL
;
788 /* prevent recursion (from NMIs) */
789 if (atomic_inc_return(&stat
->disabled
) != 1)
793 * Try to find the function again since an NMI
794 * could have added it
796 rec
= ftrace_find_profiled_func(stat
, ip
);
800 if (stat
->pages
->index
== PROFILES_PER_PAGE
) {
801 if (!stat
->pages
->next
)
803 stat
->pages
= stat
->pages
->next
;
806 rec
= &stat
->pages
->records
[stat
->pages
->index
++];
808 ftrace_add_profile(stat
, rec
);
811 atomic_dec(&stat
->disabled
);
817 function_profile_call(unsigned long ip
, unsigned long parent_ip
,
818 struct ftrace_ops
*ops
, struct pt_regs
*regs
)
820 struct ftrace_profile_stat
*stat
;
821 struct ftrace_profile
*rec
;
824 if (!ftrace_profile_enabled
)
827 local_irq_save(flags
);
829 stat
= this_cpu_ptr(&ftrace_profile_stats
);
830 if (!stat
->hash
|| !ftrace_profile_enabled
)
833 rec
= ftrace_find_profiled_func(stat
, ip
);
835 rec
= ftrace_profile_alloc(stat
, ip
);
842 local_irq_restore(flags
);
845 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
846 static int profile_graph_entry(struct ftrace_graph_ent
*trace
)
848 function_profile_call(trace
->func
, 0, NULL
, NULL
);
852 static void profile_graph_return(struct ftrace_graph_ret
*trace
)
854 struct ftrace_profile_stat
*stat
;
855 unsigned long long calltime
;
856 struct ftrace_profile
*rec
;
859 local_irq_save(flags
);
860 stat
= this_cpu_ptr(&ftrace_profile_stats
);
861 if (!stat
->hash
|| !ftrace_profile_enabled
)
864 /* If the calltime was zero'd ignore it */
865 if (!trace
->calltime
)
868 calltime
= trace
->rettime
- trace
->calltime
;
870 if (!(trace_flags
& TRACE_ITER_GRAPH_TIME
)) {
873 index
= trace
->depth
;
875 /* Append this call time to the parent time to subtract */
877 current
->ret_stack
[index
- 1].subtime
+= calltime
;
879 if (current
->ret_stack
[index
].subtime
< calltime
)
880 calltime
-= current
->ret_stack
[index
].subtime
;
885 rec
= ftrace_find_profiled_func(stat
, trace
->func
);
887 rec
->time
+= calltime
;
888 rec
->time_squared
+= calltime
* calltime
;
892 local_irq_restore(flags
);
895 static int register_ftrace_profiler(void)
897 return register_ftrace_graph(&profile_graph_return
,
898 &profile_graph_entry
);
901 static void unregister_ftrace_profiler(void)
903 unregister_ftrace_graph();
906 static struct ftrace_ops ftrace_profile_ops __read_mostly
= {
907 .func
= function_profile_call
,
908 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
909 INIT_OPS_HASH(ftrace_profile_ops
)
912 static int register_ftrace_profiler(void)
914 return register_ftrace_function(&ftrace_profile_ops
);
917 static void unregister_ftrace_profiler(void)
919 unregister_ftrace_function(&ftrace_profile_ops
);
921 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
924 ftrace_profile_write(struct file
*filp
, const char __user
*ubuf
,
925 size_t cnt
, loff_t
*ppos
)
930 ret
= kstrtoul_from_user(ubuf
, cnt
, 10, &val
);
936 mutex_lock(&ftrace_profile_lock
);
937 if (ftrace_profile_enabled
^ val
) {
939 ret
= ftrace_profile_init();
945 ret
= register_ftrace_profiler();
950 ftrace_profile_enabled
= 1;
952 ftrace_profile_enabled
= 0;
954 * unregister_ftrace_profiler calls stop_machine
955 * so this acts like an synchronize_sched.
957 unregister_ftrace_profiler();
961 mutex_unlock(&ftrace_profile_lock
);
969 ftrace_profile_read(struct file
*filp
, char __user
*ubuf
,
970 size_t cnt
, loff_t
*ppos
)
972 char buf
[64]; /* big enough to hold a number */
975 r
= sprintf(buf
, "%u\n", ftrace_profile_enabled
);
976 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
979 static const struct file_operations ftrace_profile_fops
= {
980 .open
= tracing_open_generic
,
981 .read
= ftrace_profile_read
,
982 .write
= ftrace_profile_write
,
983 .llseek
= default_llseek
,
986 /* used to initialize the real stat files */
987 static struct tracer_stat function_stats __initdata
= {
989 .stat_start
= function_stat_start
,
990 .stat_next
= function_stat_next
,
991 .stat_cmp
= function_stat_cmp
,
992 .stat_headers
= function_stat_headers
,
993 .stat_show
= function_stat_show
996 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
998 struct ftrace_profile_stat
*stat
;
999 struct dentry
*entry
;
1004 for_each_possible_cpu(cpu
) {
1005 stat
= &per_cpu(ftrace_profile_stats
, cpu
);
1007 /* allocate enough for function name + cpu number */
1008 name
= kmalloc(32, GFP_KERNEL
);
1011 * The files created are permanent, if something happens
1012 * we still do not free memory.
1015 "Could not allocate stat file for cpu %d\n",
1019 stat
->stat
= function_stats
;
1020 snprintf(name
, 32, "function%d", cpu
);
1021 stat
->stat
.name
= name
;
1022 ret
= register_stat_tracer(&stat
->stat
);
1025 "Could not register function stat for cpu %d\n",
1032 entry
= debugfs_create_file("function_profile_enabled", 0644,
1033 d_tracer
, NULL
, &ftrace_profile_fops
);
1035 pr_warning("Could not create debugfs "
1036 "'function_profile_enabled' entry\n");
1039 #else /* CONFIG_FUNCTION_PROFILER */
1040 static __init
void ftrace_profile_debugfs(struct dentry
*d_tracer
)
1043 #endif /* CONFIG_FUNCTION_PROFILER */
1045 static struct pid
* const ftrace_swapper_pid
= &init_struct_pid
;
1047 #ifdef CONFIG_DYNAMIC_FTRACE
1049 static struct ftrace_ops
*removed_ops
;
1051 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1052 # error Dynamic ftrace depends on MCOUNT_RECORD
1055 static struct hlist_head ftrace_func_hash
[FTRACE_FUNC_HASHSIZE
] __read_mostly
;
1057 struct ftrace_func_probe
{
1058 struct hlist_node node
;
1059 struct ftrace_probe_ops
*ops
;
1060 unsigned long flags
;
1063 struct list_head free_list
;
1066 struct ftrace_func_entry
{
1067 struct hlist_node hlist
;
1071 struct ftrace_hash
{
1072 unsigned long size_bits
;
1073 struct hlist_head
*buckets
;
1074 unsigned long count
;
1075 struct rcu_head rcu
;
1079 * We make these constant because no one should touch them,
1080 * but they are used as the default "empty hash", to avoid allocating
1081 * it all the time. These are in a read only section such that if
1082 * anyone does try to modify it, it will cause an exception.
1084 static const struct hlist_head empty_buckets
[1];
1085 static const struct ftrace_hash empty_hash
= {
1086 .buckets
= (struct hlist_head
*)empty_buckets
,
1088 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1090 static struct ftrace_ops global_ops
= {
1091 .func
= ftrace_stub
,
1092 .local_hash
.notrace_hash
= EMPTY_HASH
,
1093 .local_hash
.filter_hash
= EMPTY_HASH
,
1094 INIT_OPS_HASH(global_ops
)
1095 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
1096 FTRACE_OPS_FL_INITIALIZED
,
1099 struct ftrace_page
{
1100 struct ftrace_page
*next
;
1101 struct dyn_ftrace
*records
;
1106 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1107 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1109 /* estimate from running different kernels */
1110 #define NR_TO_INIT 10000
1112 static struct ftrace_page
*ftrace_pages_start
;
1113 static struct ftrace_page
*ftrace_pages
;
1115 static bool __always_inline
ftrace_hash_empty(struct ftrace_hash
*hash
)
1117 return !hash
|| !hash
->count
;
1120 static struct ftrace_func_entry
*
1121 ftrace_lookup_ip(struct ftrace_hash
*hash
, unsigned long ip
)
1124 struct ftrace_func_entry
*entry
;
1125 struct hlist_head
*hhd
;
1127 if (ftrace_hash_empty(hash
))
1130 if (hash
->size_bits
> 0)
1131 key
= hash_long(ip
, hash
->size_bits
);
1135 hhd
= &hash
->buckets
[key
];
1137 hlist_for_each_entry_rcu_notrace(entry
, hhd
, hlist
) {
1138 if (entry
->ip
== ip
)
1144 static void __add_hash_entry(struct ftrace_hash
*hash
,
1145 struct ftrace_func_entry
*entry
)
1147 struct hlist_head
*hhd
;
1150 if (hash
->size_bits
)
1151 key
= hash_long(entry
->ip
, hash
->size_bits
);
1155 hhd
= &hash
->buckets
[key
];
1156 hlist_add_head(&entry
->hlist
, hhd
);
1160 static int add_hash_entry(struct ftrace_hash
*hash
, unsigned long ip
)
1162 struct ftrace_func_entry
*entry
;
1164 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
1169 __add_hash_entry(hash
, entry
);
1175 free_hash_entry(struct ftrace_hash
*hash
,
1176 struct ftrace_func_entry
*entry
)
1178 hlist_del(&entry
->hlist
);
1184 remove_hash_entry(struct ftrace_hash
*hash
,
1185 struct ftrace_func_entry
*entry
)
1187 hlist_del(&entry
->hlist
);
1191 static void ftrace_hash_clear(struct ftrace_hash
*hash
)
1193 struct hlist_head
*hhd
;
1194 struct hlist_node
*tn
;
1195 struct ftrace_func_entry
*entry
;
1196 int size
= 1 << hash
->size_bits
;
1202 for (i
= 0; i
< size
; i
++) {
1203 hhd
= &hash
->buckets
[i
];
1204 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
)
1205 free_hash_entry(hash
, entry
);
1207 FTRACE_WARN_ON(hash
->count
);
1210 static void free_ftrace_hash(struct ftrace_hash
*hash
)
1212 if (!hash
|| hash
== EMPTY_HASH
)
1214 ftrace_hash_clear(hash
);
1215 kfree(hash
->buckets
);
1219 static void __free_ftrace_hash_rcu(struct rcu_head
*rcu
)
1221 struct ftrace_hash
*hash
;
1223 hash
= container_of(rcu
, struct ftrace_hash
, rcu
);
1224 free_ftrace_hash(hash
);
1227 static void free_ftrace_hash_rcu(struct ftrace_hash
*hash
)
1229 if (!hash
|| hash
== EMPTY_HASH
)
1231 call_rcu_sched(&hash
->rcu
, __free_ftrace_hash_rcu
);
1234 void ftrace_free_filter(struct ftrace_ops
*ops
)
1236 ftrace_ops_init(ops
);
1237 free_ftrace_hash(ops
->func_hash
->filter_hash
);
1238 free_ftrace_hash(ops
->func_hash
->notrace_hash
);
1241 static struct ftrace_hash
*alloc_ftrace_hash(int size_bits
)
1243 struct ftrace_hash
*hash
;
1246 hash
= kzalloc(sizeof(*hash
), GFP_KERNEL
);
1250 size
= 1 << size_bits
;
1251 hash
->buckets
= kcalloc(size
, sizeof(*hash
->buckets
), GFP_KERNEL
);
1253 if (!hash
->buckets
) {
1258 hash
->size_bits
= size_bits
;
1263 static struct ftrace_hash
*
1264 alloc_and_copy_ftrace_hash(int size_bits
, struct ftrace_hash
*hash
)
1266 struct ftrace_func_entry
*entry
;
1267 struct ftrace_hash
*new_hash
;
1272 new_hash
= alloc_ftrace_hash(size_bits
);
1277 if (ftrace_hash_empty(hash
))
1280 size
= 1 << hash
->size_bits
;
1281 for (i
= 0; i
< size
; i
++) {
1282 hlist_for_each_entry(entry
, &hash
->buckets
[i
], hlist
) {
1283 ret
= add_hash_entry(new_hash
, entry
->ip
);
1289 FTRACE_WARN_ON(new_hash
->count
!= hash
->count
);
1294 free_ftrace_hash(new_hash
);
1299 ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1301 ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
, int filter_hash
);
1304 ftrace_hash_move(struct ftrace_ops
*ops
, int enable
,
1305 struct ftrace_hash
**dst
, struct ftrace_hash
*src
)
1307 struct ftrace_func_entry
*entry
;
1308 struct hlist_node
*tn
;
1309 struct hlist_head
*hhd
;
1310 struct ftrace_hash
*old_hash
;
1311 struct ftrace_hash
*new_hash
;
1312 int size
= src
->count
;
1317 * If the new source is empty, just free dst and assign it
1321 new_hash
= EMPTY_HASH
;
1326 * Make the hash size about 1/2 the # found
1328 for (size
/= 2; size
; size
>>= 1)
1331 /* Don't allocate too much */
1332 if (bits
> FTRACE_HASH_MAX_BITS
)
1333 bits
= FTRACE_HASH_MAX_BITS
;
1335 new_hash
= alloc_ftrace_hash(bits
);
1339 size
= 1 << src
->size_bits
;
1340 for (i
= 0; i
< size
; i
++) {
1341 hhd
= &src
->buckets
[i
];
1342 hlist_for_each_entry_safe(entry
, tn
, hhd
, hlist
) {
1343 remove_hash_entry(src
, entry
);
1344 __add_hash_entry(new_hash
, entry
);
1350 * Remove the current set, update the hash and add
1353 ftrace_hash_rec_disable_modify(ops
, enable
);
1356 rcu_assign_pointer(*dst
, new_hash
);
1357 free_ftrace_hash_rcu(old_hash
);
1359 ftrace_hash_rec_enable_modify(ops
, enable
);
1365 * Test the hashes for this ops to see if we want to call
1366 * the ops->func or not.
1368 * It's a match if the ip is in the ops->filter_hash or
1369 * the filter_hash does not exist or is empty,
1371 * the ip is not in the ops->notrace_hash.
1373 * This needs to be called with preemption disabled as
1374 * the hashes are freed with call_rcu_sched().
1377 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
1379 struct ftrace_hash
*filter_hash
;
1380 struct ftrace_hash
*notrace_hash
;
1383 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1385 * There's a small race when adding ops that the ftrace handler
1386 * that wants regs, may be called without them. We can not
1387 * allow that handler to be called if regs is NULL.
1389 if (regs
== NULL
&& (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
))
1393 filter_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->filter_hash
);
1394 notrace_hash
= rcu_dereference_raw_notrace(ops
->func_hash
->notrace_hash
);
1396 if ((ftrace_hash_empty(filter_hash
) ||
1397 ftrace_lookup_ip(filter_hash
, ip
)) &&
1398 (ftrace_hash_empty(notrace_hash
) ||
1399 !ftrace_lookup_ip(notrace_hash
, ip
)))
1408 * This is a double for. Do not use 'break' to break out of the loop,
1409 * you must use a goto.
1411 #define do_for_each_ftrace_rec(pg, rec) \
1412 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1414 for (_____i = 0; _____i < pg->index; _____i++) { \
1415 rec = &pg->records[_____i];
1417 #define while_for_each_ftrace_rec() \
1422 static int ftrace_cmp_recs(const void *a
, const void *b
)
1424 const struct dyn_ftrace
*key
= a
;
1425 const struct dyn_ftrace
*rec
= b
;
1427 if (key
->flags
< rec
->ip
)
1429 if (key
->ip
>= rec
->ip
+ MCOUNT_INSN_SIZE
)
1434 static unsigned long ftrace_location_range(unsigned long start
, unsigned long end
)
1436 struct ftrace_page
*pg
;
1437 struct dyn_ftrace
*rec
;
1438 struct dyn_ftrace key
;
1441 key
.flags
= end
; /* overload flags, as it is unsigned long */
1443 for (pg
= ftrace_pages_start
; pg
; pg
= pg
->next
) {
1444 if (end
< pg
->records
[0].ip
||
1445 start
>= (pg
->records
[pg
->index
- 1].ip
+ MCOUNT_INSN_SIZE
))
1447 rec
= bsearch(&key
, pg
->records
, pg
->index
,
1448 sizeof(struct dyn_ftrace
),
1458 * ftrace_location - return true if the ip giving is a traced location
1459 * @ip: the instruction pointer to check
1461 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1462 * That is, the instruction that is either a NOP or call to
1463 * the function tracer. It checks the ftrace internal tables to
1464 * determine if the address belongs or not.
1466 unsigned long ftrace_location(unsigned long ip
)
1468 return ftrace_location_range(ip
, ip
);
1472 * ftrace_text_reserved - return true if range contains an ftrace location
1473 * @start: start of range to search
1474 * @end: end of range to search (inclusive). @end points to the last byte to check.
1476 * Returns 1 if @start and @end contains a ftrace location.
1477 * That is, the instruction that is either a NOP or call to
1478 * the function tracer. It checks the ftrace internal tables to
1479 * determine if the address belongs or not.
1481 int ftrace_text_reserved(const void *start
, const void *end
)
1485 ret
= ftrace_location_range((unsigned long)start
,
1486 (unsigned long)end
);
1491 /* Test if ops registered to this rec needs regs */
1492 static bool test_rec_ops_needs_regs(struct dyn_ftrace
*rec
)
1494 struct ftrace_ops
*ops
;
1495 bool keep_regs
= false;
1497 for (ops
= ftrace_ops_list
;
1498 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
1499 /* pass rec in as regs to have non-NULL val */
1500 if (ftrace_ops_test(ops
, rec
->ip
, rec
)) {
1501 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1511 static void ftrace_remove_tramp(struct ftrace_ops
*ops
,
1512 struct dyn_ftrace
*rec
)
1514 /* If TRAMP is not set, no ops should have a trampoline for this */
1515 if (!(rec
->flags
& FTRACE_FL_TRAMP
))
1518 rec
->flags
&= ~FTRACE_FL_TRAMP
;
1520 if ((!ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
1521 !ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
)) ||
1522 ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
))
1525 * The tramp_hash entry will be removed at time
1528 ops
->nr_trampolines
--;
1531 static void ftrace_clear_tramps(struct dyn_ftrace
*rec
, struct ftrace_ops
*ops
)
1533 struct ftrace_ops
*op
;
1535 /* If TRAMP is not set, no ops should have a trampoline for this */
1536 if (!(rec
->flags
& FTRACE_FL_TRAMP
))
1539 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1541 * This function is called to clear other tramps
1542 * not the one that is being updated.
1546 if (op
->nr_trampolines
)
1547 ftrace_remove_tramp(op
, rec
);
1548 } while_for_each_ftrace_op(op
);
1551 static void __ftrace_hash_rec_update(struct ftrace_ops
*ops
,
1555 struct ftrace_hash
*hash
;
1556 struct ftrace_hash
*other_hash
;
1557 struct ftrace_page
*pg
;
1558 struct dyn_ftrace
*rec
;
1562 /* Only update if the ops has been registered */
1563 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
1567 * In the filter_hash case:
1568 * If the count is zero, we update all records.
1569 * Otherwise we just update the items in the hash.
1571 * In the notrace_hash case:
1572 * We enable the update in the hash.
1573 * As disabling notrace means enabling the tracing,
1574 * and enabling notrace means disabling, the inc variable
1578 hash
= ops
->func_hash
->filter_hash
;
1579 other_hash
= ops
->func_hash
->notrace_hash
;
1580 if (ftrace_hash_empty(hash
))
1584 hash
= ops
->func_hash
->notrace_hash
;
1585 other_hash
= ops
->func_hash
->filter_hash
;
1587 * If the notrace hash has no items,
1588 * then there's nothing to do.
1590 if (ftrace_hash_empty(hash
))
1594 do_for_each_ftrace_rec(pg
, rec
) {
1595 int in_other_hash
= 0;
1601 * Only the filter_hash affects all records.
1602 * Update if the record is not in the notrace hash.
1604 if (!other_hash
|| !ftrace_lookup_ip(other_hash
, rec
->ip
))
1607 in_hash
= !!ftrace_lookup_ip(hash
, rec
->ip
);
1608 in_other_hash
= !!ftrace_lookup_ip(other_hash
, rec
->ip
);
1611 * If filter_hash is set, we want to match all functions
1612 * that are in the hash but not in the other hash.
1614 * If filter_hash is not set, then we are decrementing.
1615 * That means we match anything that is in the hash
1616 * and also in the other_hash. That is, we need to turn
1617 * off functions in the other hash because they are disabled
1620 if (filter_hash
&& in_hash
&& !in_other_hash
)
1622 else if (!filter_hash
&& in_hash
&&
1623 (in_other_hash
|| ftrace_hash_empty(other_hash
)))
1631 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == FTRACE_REF_MAX
))
1635 * If there's only a single callback registered to a
1636 * function, and the ops has a trampoline registered
1637 * for it, then we can call it directly.
1639 if (ftrace_rec_count(rec
) == 1 && ops
->trampoline
) {
1640 rec
->flags
|= FTRACE_FL_TRAMP
;
1641 ops
->nr_trampolines
++;
1644 * If we are adding another function callback
1645 * to this function, and the previous had a
1646 * custom trampoline in use, then we need to go
1647 * back to the default trampoline.
1649 ftrace_clear_tramps(rec
, ops
);
1653 * If any ops wants regs saved for this function
1654 * then all ops will get saved regs.
1656 if (ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
)
1657 rec
->flags
|= FTRACE_FL_REGS
;
1659 if (FTRACE_WARN_ON(ftrace_rec_count(rec
) == 0))
1663 if (ops
->trampoline
&& !ftrace_rec_count(rec
))
1664 ftrace_remove_tramp(ops
, rec
);
1667 * If the rec had REGS enabled and the ops that is
1668 * being removed had REGS set, then see if there is
1669 * still any ops for this record that wants regs.
1670 * If not, we can stop recording them.
1672 if (ftrace_rec_count(rec
) > 0 &&
1673 rec
->flags
& FTRACE_FL_REGS
&&
1674 ops
->flags
& FTRACE_OPS_FL_SAVE_REGS
) {
1675 if (!test_rec_ops_needs_regs(rec
))
1676 rec
->flags
&= ~FTRACE_FL_REGS
;
1680 * flags will be cleared in ftrace_check_record()
1681 * if rec count is zero.
1685 /* Shortcut, if we handled all records, we are done. */
1686 if (!all
&& count
== hash
->count
)
1688 } while_for_each_ftrace_rec();
1691 static void ftrace_hash_rec_disable(struct ftrace_ops
*ops
,
1694 __ftrace_hash_rec_update(ops
, filter_hash
, 0);
1697 static void ftrace_hash_rec_enable(struct ftrace_ops
*ops
,
1700 __ftrace_hash_rec_update(ops
, filter_hash
, 1);
1703 static void ftrace_hash_rec_update_modify(struct ftrace_ops
*ops
,
1704 int filter_hash
, int inc
)
1706 struct ftrace_ops
*op
;
1708 __ftrace_hash_rec_update(ops
, filter_hash
, inc
);
1710 if (ops
->func_hash
!= &global_ops
.local_hash
)
1714 * If the ops shares the global_ops hash, then we need to update
1715 * all ops that are enabled and use this hash.
1717 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1721 if (op
->func_hash
== &global_ops
.local_hash
)
1722 __ftrace_hash_rec_update(op
, filter_hash
, inc
);
1723 } while_for_each_ftrace_op(op
);
1726 static void ftrace_hash_rec_disable_modify(struct ftrace_ops
*ops
,
1729 ftrace_hash_rec_update_modify(ops
, filter_hash
, 0);
1732 static void ftrace_hash_rec_enable_modify(struct ftrace_ops
*ops
,
1735 ftrace_hash_rec_update_modify(ops
, filter_hash
, 1);
1738 static void print_ip_ins(const char *fmt
, unsigned char *p
)
1742 printk(KERN_CONT
"%s", fmt
);
1744 for (i
= 0; i
< MCOUNT_INSN_SIZE
; i
++)
1745 printk(KERN_CONT
"%s%02x", i
? ":" : "", p
[i
]);
1749 * ftrace_bug - report and shutdown function tracer
1750 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1751 * @ip: The address that failed
1753 * The arch code that enables or disables the function tracing
1754 * can call ftrace_bug() when it has detected a problem in
1755 * modifying the code. @failed should be one of either:
1756 * EFAULT - if the problem happens on reading the @ip address
1757 * EINVAL - if what is read at @ip is not what was expected
1758 * EPERM - if the problem happens on writting to the @ip address
1760 void ftrace_bug(int failed
, unsigned long ip
)
1764 FTRACE_WARN_ON_ONCE(1);
1765 pr_info("ftrace faulted on modifying ");
1769 FTRACE_WARN_ON_ONCE(1);
1770 pr_info("ftrace failed to modify ");
1772 print_ip_ins(" actual: ", (unsigned char *)ip
);
1773 printk(KERN_CONT
"\n");
1776 FTRACE_WARN_ON_ONCE(1);
1777 pr_info("ftrace faulted on writing ");
1781 FTRACE_WARN_ON_ONCE(1);
1782 pr_info("ftrace faulted on unknown error ");
1787 static int ftrace_check_record(struct dyn_ftrace
*rec
, int enable
, int update
)
1789 unsigned long flag
= 0UL;
1792 * If we are updating calls:
1794 * If the record has a ref count, then we need to enable it
1795 * because someone is using it.
1797 * Otherwise we make sure its disabled.
1799 * If we are disabling calls, then disable all records that
1802 if (enable
&& ftrace_rec_count(rec
))
1803 flag
= FTRACE_FL_ENABLED
;
1806 * If enabling and the REGS flag does not match the REGS_EN, or
1807 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
1808 * this record. Set flags to fail the compare against ENABLED.
1811 if (!(rec
->flags
& FTRACE_FL_REGS
) !=
1812 !(rec
->flags
& FTRACE_FL_REGS_EN
))
1813 flag
|= FTRACE_FL_REGS
;
1815 if (!(rec
->flags
& FTRACE_FL_TRAMP
) !=
1816 !(rec
->flags
& FTRACE_FL_TRAMP_EN
))
1817 flag
|= FTRACE_FL_TRAMP
;
1820 /* If the state of this record hasn't changed, then do nothing */
1821 if ((rec
->flags
& FTRACE_FL_ENABLED
) == flag
)
1822 return FTRACE_UPDATE_IGNORE
;
1825 /* Save off if rec is being enabled (for return value) */
1826 flag
^= rec
->flags
& FTRACE_FL_ENABLED
;
1829 rec
->flags
|= FTRACE_FL_ENABLED
;
1830 if (flag
& FTRACE_FL_REGS
) {
1831 if (rec
->flags
& FTRACE_FL_REGS
)
1832 rec
->flags
|= FTRACE_FL_REGS_EN
;
1834 rec
->flags
&= ~FTRACE_FL_REGS_EN
;
1836 if (flag
& FTRACE_FL_TRAMP
) {
1837 if (rec
->flags
& FTRACE_FL_TRAMP
)
1838 rec
->flags
|= FTRACE_FL_TRAMP_EN
;
1840 rec
->flags
&= ~FTRACE_FL_TRAMP_EN
;
1845 * If this record is being updated from a nop, then
1846 * return UPDATE_MAKE_CALL.
1848 * return UPDATE_MODIFY_CALL to tell the caller to convert
1849 * from the save regs, to a non-save regs function or
1850 * vice versa, or from a trampoline call.
1852 if (flag
& FTRACE_FL_ENABLED
)
1853 return FTRACE_UPDATE_MAKE_CALL
;
1855 return FTRACE_UPDATE_MODIFY_CALL
;
1859 /* If there's no more users, clear all flags */
1860 if (!ftrace_rec_count(rec
))
1863 /* Just disable the record (keep REGS state) */
1864 rec
->flags
&= ~FTRACE_FL_ENABLED
;
1867 return FTRACE_UPDATE_MAKE_NOP
;
1871 * ftrace_update_record, set a record that now is tracing or not
1872 * @rec: the record to update
1873 * @enable: set to 1 if the record is tracing, zero to force disable
1875 * The records that represent all functions that can be traced need
1876 * to be updated when tracing has been enabled.
1878 int ftrace_update_record(struct dyn_ftrace
*rec
, int enable
)
1880 return ftrace_check_record(rec
, enable
, 1);
1884 * ftrace_test_record, check if the record has been enabled or not
1885 * @rec: the record to test
1886 * @enable: set to 1 to check if enabled, 0 if it is disabled
1888 * The arch code may need to test if a record is already set to
1889 * tracing to determine how to modify the function code that it
1892 int ftrace_test_record(struct dyn_ftrace
*rec
, int enable
)
1894 return ftrace_check_record(rec
, enable
, 0);
1897 static struct ftrace_ops
*
1898 ftrace_find_tramp_ops_curr(struct dyn_ftrace
*rec
)
1900 struct ftrace_ops
*op
;
1902 /* Removed ops need to be tested first */
1903 if (removed_ops
&& removed_ops
->tramp_hash
) {
1904 if (ftrace_lookup_ip(removed_ops
->tramp_hash
, rec
->ip
))
1908 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1909 if (!op
->tramp_hash
)
1912 if (ftrace_lookup_ip(op
->tramp_hash
, rec
->ip
))
1915 } while_for_each_ftrace_op(op
);
1920 static struct ftrace_ops
*
1921 ftrace_find_tramp_ops_new(struct dyn_ftrace
*rec
)
1923 struct ftrace_ops
*op
;
1925 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
1926 /* pass rec in as regs to have non-NULL val */
1927 if (ftrace_ops_test(op
, rec
->ip
, rec
))
1929 } while_for_each_ftrace_op(op
);
1935 * ftrace_get_addr_new - Get the call address to set to
1936 * @rec: The ftrace record descriptor
1938 * If the record has the FTRACE_FL_REGS set, that means that it
1939 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
1940 * is not not set, then it wants to convert to the normal callback.
1942 * Returns the address of the trampoline to set to
1944 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
)
1946 struct ftrace_ops
*ops
;
1948 /* Trampolines take precedence over regs */
1949 if (rec
->flags
& FTRACE_FL_TRAMP
) {
1950 ops
= ftrace_find_tramp_ops_new(rec
);
1951 if (FTRACE_WARN_ON(!ops
|| !ops
->trampoline
)) {
1952 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
1953 (void *)rec
->ip
, (void *)rec
->ip
, rec
->flags
);
1954 /* Ftrace is shutting down, return anything */
1955 return (unsigned long)FTRACE_ADDR
;
1957 return ops
->trampoline
;
1960 if (rec
->flags
& FTRACE_FL_REGS
)
1961 return (unsigned long)FTRACE_REGS_ADDR
;
1963 return (unsigned long)FTRACE_ADDR
;
1967 * ftrace_get_addr_curr - Get the call address that is already there
1968 * @rec: The ftrace record descriptor
1970 * The FTRACE_FL_REGS_EN is set when the record already points to
1971 * a function that saves all the regs. Basically the '_EN' version
1972 * represents the current state of the function.
1974 * Returns the address of the trampoline that is currently being called
1976 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
)
1978 struct ftrace_ops
*ops
;
1980 /* Trampolines take precedence over regs */
1981 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
1982 ops
= ftrace_find_tramp_ops_curr(rec
);
1983 if (FTRACE_WARN_ON(!ops
)) {
1984 pr_warning("Bad trampoline accounting at: %p (%pS)\n",
1985 (void *)rec
->ip
, (void *)rec
->ip
);
1986 /* Ftrace is shutting down, return anything */
1987 return (unsigned long)FTRACE_ADDR
;
1989 return ops
->trampoline
;
1992 if (rec
->flags
& FTRACE_FL_REGS_EN
)
1993 return (unsigned long)FTRACE_REGS_ADDR
;
1995 return (unsigned long)FTRACE_ADDR
;
1999 __ftrace_replace_code(struct dyn_ftrace
*rec
, int enable
)
2001 unsigned long ftrace_old_addr
;
2002 unsigned long ftrace_addr
;
2005 ftrace_addr
= ftrace_get_addr_new(rec
);
2007 /* This needs to be done before we call ftrace_update_record */
2008 ftrace_old_addr
= ftrace_get_addr_curr(rec
);
2010 ret
= ftrace_update_record(rec
, enable
);
2013 case FTRACE_UPDATE_IGNORE
:
2016 case FTRACE_UPDATE_MAKE_CALL
:
2017 return ftrace_make_call(rec
, ftrace_addr
);
2019 case FTRACE_UPDATE_MAKE_NOP
:
2020 return ftrace_make_nop(NULL
, rec
, ftrace_old_addr
);
2022 case FTRACE_UPDATE_MODIFY_CALL
:
2023 return ftrace_modify_call(rec
, ftrace_old_addr
, ftrace_addr
);
2026 return -1; /* unknow ftrace bug */
2029 void __weak
ftrace_replace_code(int enable
)
2031 struct dyn_ftrace
*rec
;
2032 struct ftrace_page
*pg
;
2035 if (unlikely(ftrace_disabled
))
2038 do_for_each_ftrace_rec(pg
, rec
) {
2039 failed
= __ftrace_replace_code(rec
, enable
);
2041 ftrace_bug(failed
, rec
->ip
);
2042 /* Stop processing */
2045 } while_for_each_ftrace_rec();
2048 struct ftrace_rec_iter
{
2049 struct ftrace_page
*pg
;
2054 * ftrace_rec_iter_start, start up iterating over traced functions
2056 * Returns an iterator handle that is used to iterate over all
2057 * the records that represent address locations where functions
2060 * May return NULL if no records are available.
2062 struct ftrace_rec_iter
*ftrace_rec_iter_start(void)
2065 * We only use a single iterator.
2066 * Protected by the ftrace_lock mutex.
2068 static struct ftrace_rec_iter ftrace_rec_iter
;
2069 struct ftrace_rec_iter
*iter
= &ftrace_rec_iter
;
2071 iter
->pg
= ftrace_pages_start
;
2074 /* Could have empty pages */
2075 while (iter
->pg
&& !iter
->pg
->index
)
2076 iter
->pg
= iter
->pg
->next
;
2085 * ftrace_rec_iter_next, get the next record to process.
2086 * @iter: The handle to the iterator.
2088 * Returns the next iterator after the given iterator @iter.
2090 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
)
2094 if (iter
->index
>= iter
->pg
->index
) {
2095 iter
->pg
= iter
->pg
->next
;
2098 /* Could have empty pages */
2099 while (iter
->pg
&& !iter
->pg
->index
)
2100 iter
->pg
= iter
->pg
->next
;
2110 * ftrace_rec_iter_record, get the record at the iterator location
2111 * @iter: The current iterator location
2113 * Returns the record that the current @iter is at.
2115 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
)
2117 return &iter
->pg
->records
[iter
->index
];
2121 ftrace_code_disable(struct module
*mod
, struct dyn_ftrace
*rec
)
2128 if (unlikely(ftrace_disabled
))
2131 ret
= ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
2133 ftrace_bug(ret
, ip
);
2140 * archs can override this function if they must do something
2141 * before the modifying code is performed.
2143 int __weak
ftrace_arch_code_modify_prepare(void)
2149 * archs can override this function if they must do something
2150 * after the modifying code is performed.
2152 int __weak
ftrace_arch_code_modify_post_process(void)
2157 void ftrace_modify_all_code(int command
)
2159 int update
= command
& FTRACE_UPDATE_TRACE_FUNC
;
2163 * If the ftrace_caller calls a ftrace_ops func directly,
2164 * we need to make sure that it only traces functions it
2165 * expects to trace. When doing the switch of functions,
2166 * we need to update to the ftrace_ops_list_func first
2167 * before the transition between old and new calls are set,
2168 * as the ftrace_ops_list_func will check the ops hashes
2169 * to make sure the ops are having the right functions
2173 err
= ftrace_update_ftrace_func(ftrace_ops_list_func
);
2174 if (FTRACE_WARN_ON(err
))
2178 if (command
& FTRACE_UPDATE_CALLS
)
2179 ftrace_replace_code(1);
2180 else if (command
& FTRACE_DISABLE_CALLS
)
2181 ftrace_replace_code(0);
2183 if (update
&& ftrace_trace_function
!= ftrace_ops_list_func
) {
2184 function_trace_op
= set_function_trace_op
;
2186 /* If irqs are disabled, we are in stop machine */
2187 if (!irqs_disabled())
2188 smp_call_function(ftrace_sync_ipi
, NULL
, 1);
2189 err
= ftrace_update_ftrace_func(ftrace_trace_function
);
2190 if (FTRACE_WARN_ON(err
))
2194 if (command
& FTRACE_START_FUNC_RET
)
2195 err
= ftrace_enable_ftrace_graph_caller();
2196 else if (command
& FTRACE_STOP_FUNC_RET
)
2197 err
= ftrace_disable_ftrace_graph_caller();
2198 FTRACE_WARN_ON(err
);
2201 static int __ftrace_modify_code(void *data
)
2203 int *command
= data
;
2205 ftrace_modify_all_code(*command
);
2211 * ftrace_run_stop_machine, go back to the stop machine method
2212 * @command: The command to tell ftrace what to do
2214 * If an arch needs to fall back to the stop machine method, the
2215 * it can call this function.
2217 void ftrace_run_stop_machine(int command
)
2219 stop_machine(__ftrace_modify_code
, &command
, NULL
);
2223 * arch_ftrace_update_code, modify the code to trace or not trace
2224 * @command: The command that needs to be done
2226 * Archs can override this function if it does not need to
2227 * run stop_machine() to modify code.
2229 void __weak
arch_ftrace_update_code(int command
)
2231 ftrace_run_stop_machine(command
);
2234 static int ftrace_save_ops_tramp_hash(struct ftrace_ops
*ops
)
2236 struct ftrace_page
*pg
;
2237 struct dyn_ftrace
*rec
;
2241 size
= ops
->nr_trampolines
;
2244 * Make the hash size about 1/2 the # found
2246 for (size
/= 2; size
; size
>>= 1)
2249 ops
->tramp_hash
= alloc_ftrace_hash(bits
);
2251 * TODO: a failed allocation is going to screw up
2252 * the accounting of what needs to be modified
2253 * and not. For now, we kill ftrace if we fail
2254 * to allocate here. But there are ways around this,
2255 * but that will take a little more work.
2257 if (!ops
->tramp_hash
)
2260 do_for_each_ftrace_rec(pg
, rec
) {
2261 if (ftrace_rec_count(rec
) == 1 &&
2262 ftrace_ops_test(ops
, rec
->ip
, rec
)) {
2265 * If another ops adds to a rec, the rec will
2266 * lose its trampoline and never get it back
2267 * until all ops are off of it.
2269 if (!(rec
->flags
& FTRACE_FL_TRAMP
))
2272 /* This record had better have a trampoline */
2273 if (FTRACE_WARN_ON(!(rec
->flags
& FTRACE_FL_TRAMP_EN
)))
2276 ret
= add_hash_entry(ops
->tramp_hash
, rec
->ip
);
2280 } while_for_each_ftrace_rec();
2282 /* The number of recs in the hash must match nr_trampolines */
2283 if (FTRACE_WARN_ON(ops
->tramp_hash
->count
!= ops
->nr_trampolines
))
2284 pr_warn("count=%ld trampolines=%d\n",
2285 ops
->tramp_hash
->count
,
2286 ops
->nr_trampolines
);
2291 static int ftrace_save_tramp_hashes(void)
2293 struct ftrace_ops
*op
;
2297 * Now that any trampoline is being used, we need to save the
2298 * hashes for the ops that have them. This allows the mapping
2299 * back from the record to the ops that has the trampoline to
2300 * know what code is being replaced. Modifying code must always
2301 * verify what it is changing.
2303 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
2305 /* The tramp_hash is recreated each time. */
2306 free_ftrace_hash(op
->tramp_hash
);
2307 op
->tramp_hash
= NULL
;
2309 if (op
->nr_trampolines
) {
2310 ret
= ftrace_save_ops_tramp_hash(op
);
2315 } while_for_each_ftrace_op(op
);
2320 static void ftrace_run_update_code(int command
)
2324 ret
= ftrace_arch_code_modify_prepare();
2325 FTRACE_WARN_ON(ret
);
2330 * By default we use stop_machine() to modify the code.
2331 * But archs can do what ever they want as long as it
2332 * is safe. The stop_machine() is the safest, but also
2333 * produces the most overhead.
2335 arch_ftrace_update_code(command
);
2337 ret
= ftrace_arch_code_modify_post_process();
2338 FTRACE_WARN_ON(ret
);
2340 ret
= ftrace_save_tramp_hashes();
2341 FTRACE_WARN_ON(ret
);
2344 static ftrace_func_t saved_ftrace_func
;
2345 static int ftrace_start_up
;
2347 static void control_ops_free(struct ftrace_ops
*ops
)
2349 free_percpu(ops
->disabled
);
2352 static void ftrace_startup_enable(int command
)
2354 if (saved_ftrace_func
!= ftrace_trace_function
) {
2355 saved_ftrace_func
= ftrace_trace_function
;
2356 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2359 if (!command
|| !ftrace_enabled
)
2362 ftrace_run_update_code(command
);
2365 static int ftrace_startup(struct ftrace_ops
*ops
, int command
)
2369 if (unlikely(ftrace_disabled
))
2372 ret
= __register_ftrace_function(ops
);
2377 command
|= FTRACE_UPDATE_CALLS
;
2379 ops
->flags
|= FTRACE_OPS_FL_ENABLED
;
2381 ftrace_hash_rec_enable(ops
, 1);
2383 ftrace_startup_enable(command
);
2388 static int ftrace_shutdown(struct ftrace_ops
*ops
, int command
)
2392 if (unlikely(ftrace_disabled
))
2395 ret
= __unregister_ftrace_function(ops
);
2401 * Just warn in case of unbalance, no need to kill ftrace, it's not
2402 * critical but the ftrace_call callers may be never nopped again after
2403 * further ftrace uses.
2405 WARN_ON_ONCE(ftrace_start_up
< 0);
2407 ftrace_hash_rec_disable(ops
, 1);
2409 ops
->flags
&= ~FTRACE_OPS_FL_ENABLED
;
2411 command
|= FTRACE_UPDATE_CALLS
;
2413 if (saved_ftrace_func
!= ftrace_trace_function
) {
2414 saved_ftrace_func
= ftrace_trace_function
;
2415 command
|= FTRACE_UPDATE_TRACE_FUNC
;
2418 if (!command
|| !ftrace_enabled
) {
2420 * If these are control ops, they still need their
2421 * per_cpu field freed. Since, function tracing is
2422 * not currently active, we can just free them
2423 * without synchronizing all CPUs.
2425 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
)
2426 control_ops_free(ops
);
2431 * If the ops uses a trampoline, then it needs to be
2432 * tested first on update.
2436 ftrace_run_update_code(command
);
2441 * Dynamic ops may be freed, we must make sure that all
2442 * callers are done before leaving this function.
2443 * The same goes for freeing the per_cpu data of the control
2446 * Again, normal synchronize_sched() is not good enough.
2447 * We need to do a hard force of sched synchronization.
2448 * This is because we use preempt_disable() to do RCU, but
2449 * the function tracers can be called where RCU is not watching
2450 * (like before user_exit()). We can not rely on the RCU
2451 * infrastructure to do the synchronization, thus we must do it
2454 if (ops
->flags
& (FTRACE_OPS_FL_DYNAMIC
| FTRACE_OPS_FL_CONTROL
)) {
2455 schedule_on_each_cpu(ftrace_sync
);
2457 if (ops
->flags
& FTRACE_OPS_FL_CONTROL
)
2458 control_ops_free(ops
);
2464 static void ftrace_startup_sysctl(void)
2466 if (unlikely(ftrace_disabled
))
2469 /* Force update next time */
2470 saved_ftrace_func
= NULL
;
2471 /* ftrace_start_up is true if we want ftrace running */
2472 if (ftrace_start_up
)
2473 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
2476 static void ftrace_shutdown_sysctl(void)
2478 if (unlikely(ftrace_disabled
))
2481 /* ftrace_start_up is true if ftrace is running */
2482 if (ftrace_start_up
)
2483 ftrace_run_update_code(FTRACE_DISABLE_CALLS
);
2486 static cycle_t ftrace_update_time
;
2487 unsigned long ftrace_update_tot_cnt
;
2489 static inline int ops_traces_mod(struct ftrace_ops
*ops
)
2492 * Filter_hash being empty will default to trace module.
2493 * But notrace hash requires a test of individual module functions.
2495 return ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2496 ftrace_hash_empty(ops
->func_hash
->notrace_hash
);
2500 * Check if the current ops references the record.
2502 * If the ops traces all functions, then it was already accounted for.
2503 * If the ops does not trace the current record function, skip it.
2504 * If the ops ignores the function via notrace filter, skip it.
2507 ops_references_rec(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
)
2509 /* If ops isn't enabled, ignore it */
2510 if (!(ops
->flags
& FTRACE_OPS_FL_ENABLED
))
2513 /* If ops traces all mods, we already accounted for it */
2514 if (ops_traces_mod(ops
))
2517 /* The function must be in the filter */
2518 if (!ftrace_hash_empty(ops
->func_hash
->filter_hash
) &&
2519 !ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))
2522 /* If in notrace hash, we ignore it too */
2523 if (ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
))
2529 static int referenced_filters(struct dyn_ftrace
*rec
)
2531 struct ftrace_ops
*ops
;
2534 for (ops
= ftrace_ops_list
; ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2535 if (ops_references_rec(ops
, rec
))
2542 static int ftrace_update_code(struct module
*mod
, struct ftrace_page
*new_pgs
)
2544 struct ftrace_page
*pg
;
2545 struct dyn_ftrace
*p
;
2546 cycle_t start
, stop
;
2547 unsigned long update_cnt
= 0;
2548 unsigned long ref
= 0;
2553 * When adding a module, we need to check if tracers are
2554 * currently enabled and if they are set to trace all functions.
2555 * If they are, we need to enable the module functions as well
2556 * as update the reference counts for those function records.
2559 struct ftrace_ops
*ops
;
2561 for (ops
= ftrace_ops_list
;
2562 ops
!= &ftrace_list_end
; ops
= ops
->next
) {
2563 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
) {
2564 if (ops_traces_mod(ops
))
2572 start
= ftrace_now(raw_smp_processor_id());
2574 for (pg
= new_pgs
; pg
; pg
= pg
->next
) {
2576 for (i
= 0; i
< pg
->index
; i
++) {
2579 /* If something went wrong, bail without enabling anything */
2580 if (unlikely(ftrace_disabled
))
2583 p
= &pg
->records
[i
];
2585 cnt
+= referenced_filters(p
);
2589 * Do the initial record conversion from mcount jump
2590 * to the NOP instructions.
2592 if (!ftrace_code_disable(mod
, p
))
2598 * If the tracing is enabled, go ahead and enable the record.
2600 * The reason not to enable the record immediatelly is the
2601 * inherent check of ftrace_make_nop/ftrace_make_call for
2602 * correct previous instructions. Making first the NOP
2603 * conversion puts the module to the correct state, thus
2604 * passing the ftrace_make_call check.
2606 if (ftrace_start_up
&& cnt
) {
2607 int failed
= __ftrace_replace_code(p
, 1);
2609 ftrace_bug(failed
, p
->ip
);
2614 stop
= ftrace_now(raw_smp_processor_id());
2615 ftrace_update_time
= stop
- start
;
2616 ftrace_update_tot_cnt
+= update_cnt
;
2621 static int ftrace_allocate_records(struct ftrace_page
*pg
, int count
)
2626 if (WARN_ON(!count
))
2629 order
= get_count_order(DIV_ROUND_UP(count
, ENTRIES_PER_PAGE
));
2632 * We want to fill as much as possible. No more than a page
2635 while ((PAGE_SIZE
<< order
) / ENTRY_SIZE
>= count
+ ENTRIES_PER_PAGE
)
2639 pg
->records
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, order
);
2642 /* if we can't allocate this size, try something smaller */
2649 cnt
= (PAGE_SIZE
<< order
) / ENTRY_SIZE
;
2658 static struct ftrace_page
*
2659 ftrace_allocate_pages(unsigned long num_to_init
)
2661 struct ftrace_page
*start_pg
;
2662 struct ftrace_page
*pg
;
2669 start_pg
= pg
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2674 * Try to allocate as much as possible in one continues
2675 * location that fills in all of the space. We want to
2676 * waste as little space as possible.
2679 cnt
= ftrace_allocate_records(pg
, num_to_init
);
2687 pg
->next
= kzalloc(sizeof(*pg
), GFP_KERNEL
);
2699 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
2700 free_pages((unsigned long)pg
->records
, order
);
2701 start_pg
= pg
->next
;
2705 pr_info("ftrace: FAILED to allocate memory for functions\n");
2709 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2711 struct ftrace_iterator
{
2714 struct ftrace_page
*pg
;
2715 struct dyn_ftrace
*func
;
2716 struct ftrace_func_probe
*probe
;
2717 struct trace_parser parser
;
2718 struct ftrace_hash
*hash
;
2719 struct ftrace_ops
*ops
;
2726 t_hash_next(struct seq_file
*m
, loff_t
*pos
)
2728 struct ftrace_iterator
*iter
= m
->private;
2729 struct hlist_node
*hnd
= NULL
;
2730 struct hlist_head
*hhd
;
2736 hnd
= &iter
->probe
->node
;
2738 if (iter
->hidx
>= FTRACE_FUNC_HASHSIZE
)
2741 hhd
= &ftrace_func_hash
[iter
->hidx
];
2743 if (hlist_empty(hhd
)) {
2759 if (WARN_ON_ONCE(!hnd
))
2762 iter
->probe
= hlist_entry(hnd
, struct ftrace_func_probe
, node
);
2767 static void *t_hash_start(struct seq_file
*m
, loff_t
*pos
)
2769 struct ftrace_iterator
*iter
= m
->private;
2773 if (!(iter
->flags
& FTRACE_ITER_DO_HASH
))
2776 if (iter
->func_pos
> *pos
)
2780 for (l
= 0; l
<= (*pos
- iter
->func_pos
); ) {
2781 p
= t_hash_next(m
, &l
);
2788 /* Only set this if we have an item */
2789 iter
->flags
|= FTRACE_ITER_HASH
;
2795 t_hash_show(struct seq_file
*m
, struct ftrace_iterator
*iter
)
2797 struct ftrace_func_probe
*rec
;
2800 if (WARN_ON_ONCE(!rec
))
2803 if (rec
->ops
->print
)
2804 return rec
->ops
->print(m
, rec
->ip
, rec
->ops
, rec
->data
);
2806 seq_printf(m
, "%ps:%ps", (void *)rec
->ip
, (void *)rec
->ops
->func
);
2809 seq_printf(m
, ":%p", rec
->data
);
2816 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2818 struct ftrace_iterator
*iter
= m
->private;
2819 struct ftrace_ops
*ops
= iter
->ops
;
2820 struct dyn_ftrace
*rec
= NULL
;
2822 if (unlikely(ftrace_disabled
))
2825 if (iter
->flags
& FTRACE_ITER_HASH
)
2826 return t_hash_next(m
, pos
);
2829 iter
->pos
= iter
->func_pos
= *pos
;
2831 if (iter
->flags
& FTRACE_ITER_PRINTALL
)
2832 return t_hash_start(m
, pos
);
2835 if (iter
->idx
>= iter
->pg
->index
) {
2836 if (iter
->pg
->next
) {
2837 iter
->pg
= iter
->pg
->next
;
2842 rec
= &iter
->pg
->records
[iter
->idx
++];
2843 if (((iter
->flags
& FTRACE_ITER_FILTER
) &&
2844 !(ftrace_lookup_ip(ops
->func_hash
->filter_hash
, rec
->ip
))) ||
2846 ((iter
->flags
& FTRACE_ITER_NOTRACE
) &&
2847 !ftrace_lookup_ip(ops
->func_hash
->notrace_hash
, rec
->ip
)) ||
2849 ((iter
->flags
& FTRACE_ITER_ENABLED
) &&
2850 !(rec
->flags
& FTRACE_FL_ENABLED
))) {
2858 return t_hash_start(m
, pos
);
2865 static void reset_iter_read(struct ftrace_iterator
*iter
)
2869 iter
->flags
&= ~(FTRACE_ITER_PRINTALL
| FTRACE_ITER_HASH
);
2872 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2874 struct ftrace_iterator
*iter
= m
->private;
2875 struct ftrace_ops
*ops
= iter
->ops
;
2879 mutex_lock(&ftrace_lock
);
2881 if (unlikely(ftrace_disabled
))
2885 * If an lseek was done, then reset and start from beginning.
2887 if (*pos
< iter
->pos
)
2888 reset_iter_read(iter
);
2891 * For set_ftrace_filter reading, if we have the filter
2892 * off, we can short cut and just print out that all
2893 * functions are enabled.
2895 if ((iter
->flags
& FTRACE_ITER_FILTER
&&
2896 ftrace_hash_empty(ops
->func_hash
->filter_hash
)) ||
2897 (iter
->flags
& FTRACE_ITER_NOTRACE
&&
2898 ftrace_hash_empty(ops
->func_hash
->notrace_hash
))) {
2900 return t_hash_start(m
, pos
);
2901 iter
->flags
|= FTRACE_ITER_PRINTALL
;
2902 /* reset in case of seek/pread */
2903 iter
->flags
&= ~FTRACE_ITER_HASH
;
2907 if (iter
->flags
& FTRACE_ITER_HASH
)
2908 return t_hash_start(m
, pos
);
2911 * Unfortunately, we need to restart at ftrace_pages_start
2912 * every time we let go of the ftrace_mutex. This is because
2913 * those pointers can change without the lock.
2915 iter
->pg
= ftrace_pages_start
;
2917 for (l
= 0; l
<= *pos
; ) {
2918 p
= t_next(m
, p
, &l
);
2924 return t_hash_start(m
, pos
);
2929 static void t_stop(struct seq_file
*m
, void *p
)
2931 mutex_unlock(&ftrace_lock
);
2934 static int t_show(struct seq_file
*m
, void *v
)
2936 struct ftrace_iterator
*iter
= m
->private;
2937 struct dyn_ftrace
*rec
;
2939 if (iter
->flags
& FTRACE_ITER_HASH
)
2940 return t_hash_show(m
, iter
);
2942 if (iter
->flags
& FTRACE_ITER_PRINTALL
) {
2943 if (iter
->flags
& FTRACE_ITER_NOTRACE
)
2944 seq_printf(m
, "#### no functions disabled ####\n");
2946 seq_printf(m
, "#### all functions enabled ####\n");
2955 seq_printf(m
, "%ps", (void *)rec
->ip
);
2956 if (iter
->flags
& FTRACE_ITER_ENABLED
) {
2957 seq_printf(m
, " (%ld)%s",
2958 ftrace_rec_count(rec
),
2959 rec
->flags
& FTRACE_FL_REGS
? " R" : " ");
2960 if (rec
->flags
& FTRACE_FL_TRAMP_EN
) {
2961 struct ftrace_ops
*ops
;
2963 ops
= ftrace_find_tramp_ops_curr(rec
);
2964 if (ops
&& ops
->trampoline
)
2965 seq_printf(m
, "\ttramp: %pS",
2966 (void *)ops
->trampoline
);
2968 seq_printf(m
, "\ttramp: ERROR!");
2972 seq_printf(m
, "\n");
2977 static const struct seq_operations show_ftrace_seq_ops
= {
2985 ftrace_avail_open(struct inode
*inode
, struct file
*file
)
2987 struct ftrace_iterator
*iter
;
2989 if (unlikely(ftrace_disabled
))
2992 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
2994 iter
->pg
= ftrace_pages_start
;
2995 iter
->ops
= &global_ops
;
2998 return iter
? 0 : -ENOMEM
;
3002 ftrace_enabled_open(struct inode
*inode
, struct file
*file
)
3004 struct ftrace_iterator
*iter
;
3006 if (unlikely(ftrace_disabled
))
3009 iter
= __seq_open_private(file
, &show_ftrace_seq_ops
, sizeof(*iter
));
3011 iter
->pg
= ftrace_pages_start
;
3012 iter
->flags
= FTRACE_ITER_ENABLED
;
3013 iter
->ops
= &global_ops
;
3016 return iter
? 0 : -ENOMEM
;
3020 * ftrace_regex_open - initialize function tracer filter files
3021 * @ops: The ftrace_ops that hold the hash filters
3022 * @flag: The type of filter to process
3023 * @inode: The inode, usually passed in to your open routine
3024 * @file: The file, usually passed in to your open routine
3026 * ftrace_regex_open() initializes the filter files for the
3027 * @ops. Depending on @flag it may process the filter hash or
3028 * the notrace hash of @ops. With this called from the open
3029 * routine, you can use ftrace_filter_write() for the write
3030 * routine if @flag has FTRACE_ITER_FILTER set, or
3031 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3032 * tracing_lseek() should be used as the lseek routine, and
3033 * release must call ftrace_regex_release().
3036 ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
3037 struct inode
*inode
, struct file
*file
)
3039 struct ftrace_iterator
*iter
;
3040 struct ftrace_hash
*hash
;
3043 ftrace_ops_init(ops
);
3045 if (unlikely(ftrace_disabled
))
3048 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
3052 if (trace_parser_get_init(&iter
->parser
, FTRACE_BUFF_MAX
)) {
3060 mutex_lock(&ops
->func_hash
->regex_lock
);
3062 if (flag
& FTRACE_ITER_NOTRACE
)
3063 hash
= ops
->func_hash
->notrace_hash
;
3065 hash
= ops
->func_hash
->filter_hash
;
3067 if (file
->f_mode
& FMODE_WRITE
) {
3068 const int size_bits
= FTRACE_HASH_DEFAULT_BITS
;
3070 if (file
->f_flags
& O_TRUNC
)
3071 iter
->hash
= alloc_ftrace_hash(size_bits
);
3073 iter
->hash
= alloc_and_copy_ftrace_hash(size_bits
, hash
);
3076 trace_parser_put(&iter
->parser
);
3083 if (file
->f_mode
& FMODE_READ
) {
3084 iter
->pg
= ftrace_pages_start
;
3086 ret
= seq_open(file
, &show_ftrace_seq_ops
);
3088 struct seq_file
*m
= file
->private_data
;
3092 free_ftrace_hash(iter
->hash
);
3093 trace_parser_put(&iter
->parser
);
3097 file
->private_data
= iter
;
3100 mutex_unlock(&ops
->func_hash
->regex_lock
);
3106 ftrace_filter_open(struct inode
*inode
, struct file
*file
)
3108 struct ftrace_ops
*ops
= inode
->i_private
;
3110 return ftrace_regex_open(ops
,
3111 FTRACE_ITER_FILTER
| FTRACE_ITER_DO_HASH
,
3116 ftrace_notrace_open(struct inode
*inode
, struct file
*file
)
3118 struct ftrace_ops
*ops
= inode
->i_private
;
3120 return ftrace_regex_open(ops
, FTRACE_ITER_NOTRACE
,
3124 static int ftrace_match(char *str
, char *regex
, int len
, int type
)
3131 if (strcmp(str
, regex
) == 0)
3134 case MATCH_FRONT_ONLY
:
3135 if (strncmp(str
, regex
, len
) == 0)
3138 case MATCH_MIDDLE_ONLY
:
3139 if (strstr(str
, regex
))
3142 case MATCH_END_ONLY
:
3144 if (slen
>= len
&& memcmp(str
+ slen
- len
, regex
, len
) == 0)
3153 enter_record(struct ftrace_hash
*hash
, struct dyn_ftrace
*rec
, int not)
3155 struct ftrace_func_entry
*entry
;
3158 entry
= ftrace_lookup_ip(hash
, rec
->ip
);
3160 /* Do nothing if it doesn't exist */
3164 free_hash_entry(hash
, entry
);
3166 /* Do nothing if it exists */
3170 ret
= add_hash_entry(hash
, rec
->ip
);
3176 ftrace_match_record(struct dyn_ftrace
*rec
, char *mod
,
3177 char *regex
, int len
, int type
)
3179 char str
[KSYM_SYMBOL_LEN
];
3182 kallsyms_lookup(rec
->ip
, NULL
, NULL
, &modname
, str
);
3185 /* module lookup requires matching the module */
3186 if (!modname
|| strcmp(modname
, mod
))
3189 /* blank search means to match all funcs in the mod */
3194 return ftrace_match(str
, regex
, len
, type
);
3198 match_records(struct ftrace_hash
*hash
, char *buff
,
3199 int len
, char *mod
, int not)
3201 unsigned search_len
= 0;
3202 struct ftrace_page
*pg
;
3203 struct dyn_ftrace
*rec
;
3204 int type
= MATCH_FULL
;
3205 char *search
= buff
;
3210 type
= filter_parse_regex(buff
, len
, &search
, ¬);
3211 search_len
= strlen(search
);
3214 mutex_lock(&ftrace_lock
);
3216 if (unlikely(ftrace_disabled
))
3219 do_for_each_ftrace_rec(pg
, rec
) {
3220 if (ftrace_match_record(rec
, mod
, search
, search_len
, type
)) {
3221 ret
= enter_record(hash
, rec
, not);
3228 } while_for_each_ftrace_rec();
3230 mutex_unlock(&ftrace_lock
);
3236 ftrace_match_records(struct ftrace_hash
*hash
, char *buff
, int len
)
3238 return match_records(hash
, buff
, len
, NULL
, 0);
3242 ftrace_match_module_records(struct ftrace_hash
*hash
, char *buff
, char *mod
)
3246 /* blank or '*' mean the same */
3247 if (strcmp(buff
, "*") == 0)
3250 /* handle the case of 'dont filter this module' */
3251 if (strcmp(buff
, "!") == 0 || strcmp(buff
, "!*") == 0) {
3256 return match_records(hash
, buff
, strlen(buff
), mod
, not);
3260 * We register the module command as a template to show others how
3261 * to register the a command as well.
3265 ftrace_mod_callback(struct ftrace_hash
*hash
,
3266 char *func
, char *cmd
, char *param
, int enable
)
3272 * cmd == 'mod' because we only registered this func
3273 * for the 'mod' ftrace_func_command.
3274 * But if you register one func with multiple commands,
3275 * you can tell which command was used by the cmd
3279 /* we must have a module name */
3283 mod
= strsep(¶m
, ":");
3287 ret
= ftrace_match_module_records(hash
, func
, mod
);
3296 static struct ftrace_func_command ftrace_mod_cmd
= {
3298 .func
= ftrace_mod_callback
,
3301 static int __init
ftrace_mod_cmd_init(void)
3303 return register_ftrace_command(&ftrace_mod_cmd
);
3305 core_initcall(ftrace_mod_cmd_init
);
3307 static void function_trace_probe_call(unsigned long ip
, unsigned long parent_ip
,
3308 struct ftrace_ops
*op
, struct pt_regs
*pt_regs
)
3310 struct ftrace_func_probe
*entry
;
3311 struct hlist_head
*hhd
;
3314 key
= hash_long(ip
, FTRACE_HASH_BITS
);
3316 hhd
= &ftrace_func_hash
[key
];
3318 if (hlist_empty(hhd
))
3322 * Disable preemption for these calls to prevent a RCU grace
3323 * period. This syncs the hash iteration and freeing of items
3324 * on the hash. rcu_read_lock is too dangerous here.
3326 preempt_disable_notrace();
3327 hlist_for_each_entry_rcu_notrace(entry
, hhd
, node
) {
3328 if (entry
->ip
== ip
)
3329 entry
->ops
->func(ip
, parent_ip
, &entry
->data
);
3331 preempt_enable_notrace();
3334 static struct ftrace_ops trace_probe_ops __read_mostly
=
3336 .func
= function_trace_probe_call
,
3337 .flags
= FTRACE_OPS_FL_INITIALIZED
,
3338 INIT_OPS_HASH(trace_probe_ops
)
3341 static int ftrace_probe_registered
;
3343 static void __enable_ftrace_function_probe(void)
3348 if (ftrace_probe_registered
) {
3349 /* still need to update the function call sites */
3351 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3355 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3356 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3360 /* Nothing registered? */
3361 if (i
== FTRACE_FUNC_HASHSIZE
)
3364 ret
= ftrace_startup(&trace_probe_ops
, 0);
3366 ftrace_probe_registered
= 1;
3369 static void __disable_ftrace_function_probe(void)
3373 if (!ftrace_probe_registered
)
3376 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3377 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3382 /* no more funcs left */
3383 ftrace_shutdown(&trace_probe_ops
, 0);
3385 ftrace_probe_registered
= 0;
3389 static void ftrace_free_entry(struct ftrace_func_probe
*entry
)
3391 if (entry
->ops
->free
)
3392 entry
->ops
->free(entry
->ops
, entry
->ip
, &entry
->data
);
3397 register_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3400 struct ftrace_func_probe
*entry
;
3401 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3402 struct ftrace_hash
*hash
;
3403 struct ftrace_page
*pg
;
3404 struct dyn_ftrace
*rec
;
3411 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3412 len
= strlen(search
);
3414 /* we do not support '!' for function probes */
3418 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3420 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3426 if (unlikely(ftrace_disabled
)) {
3431 mutex_lock(&ftrace_lock
);
3433 do_for_each_ftrace_rec(pg
, rec
) {
3435 if (!ftrace_match_record(rec
, NULL
, search
, len
, type
))
3438 entry
= kmalloc(sizeof(*entry
), GFP_KERNEL
);
3440 /* If we did not process any, then return error */
3451 * The caller might want to do something special
3452 * for each function we find. We call the callback
3453 * to give the caller an opportunity to do so.
3456 if (ops
->init(ops
, rec
->ip
, &entry
->data
) < 0) {
3457 /* caller does not like this func */
3463 ret
= enter_record(hash
, rec
, 0);
3471 entry
->ip
= rec
->ip
;
3473 key
= hash_long(entry
->ip
, FTRACE_HASH_BITS
);
3474 hlist_add_head_rcu(&entry
->node
, &ftrace_func_hash
[key
]);
3476 } while_for_each_ftrace_rec();
3478 ret
= ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3482 __enable_ftrace_function_probe();
3485 mutex_unlock(&ftrace_lock
);
3487 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3488 free_ftrace_hash(hash
);
3494 PROBE_TEST_FUNC
= 1,
3499 __unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3500 void *data
, int flags
)
3502 struct ftrace_func_entry
*rec_entry
;
3503 struct ftrace_func_probe
*entry
;
3504 struct ftrace_func_probe
*p
;
3505 struct ftrace_hash
**orig_hash
= &trace_probe_ops
.func_hash
->filter_hash
;
3506 struct list_head free_list
;
3507 struct ftrace_hash
*hash
;
3508 struct hlist_node
*tmp
;
3509 char str
[KSYM_SYMBOL_LEN
];
3510 int type
= MATCH_FULL
;
3514 if (glob
&& (strcmp(glob
, "*") == 0 || !strlen(glob
)))
3519 type
= filter_parse_regex(glob
, strlen(glob
), &search
, ¬);
3520 len
= strlen(search
);
3522 /* we do not support '!' for function probes */
3527 mutex_lock(&trace_probe_ops
.func_hash
->regex_lock
);
3529 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3531 /* Hmm, should report this somehow */
3534 INIT_LIST_HEAD(&free_list
);
3536 for (i
= 0; i
< FTRACE_FUNC_HASHSIZE
; i
++) {
3537 struct hlist_head
*hhd
= &ftrace_func_hash
[i
];
3539 hlist_for_each_entry_safe(entry
, tmp
, hhd
, node
) {
3541 /* break up if statements for readability */
3542 if ((flags
& PROBE_TEST_FUNC
) && entry
->ops
!= ops
)
3545 if ((flags
& PROBE_TEST_DATA
) && entry
->data
!= data
)
3548 /* do this last, since it is the most expensive */
3550 kallsyms_lookup(entry
->ip
, NULL
, NULL
,
3552 if (!ftrace_match(str
, glob
, len
, type
))
3556 rec_entry
= ftrace_lookup_ip(hash
, entry
->ip
);
3557 /* It is possible more than one entry had this ip */
3559 free_hash_entry(hash
, rec_entry
);
3561 hlist_del_rcu(&entry
->node
);
3562 list_add(&entry
->free_list
, &free_list
);
3565 mutex_lock(&ftrace_lock
);
3566 __disable_ftrace_function_probe();
3568 * Remove after the disable is called. Otherwise, if the last
3569 * probe is removed, a null hash means *all enabled*.
3571 ftrace_hash_move(&trace_probe_ops
, 1, orig_hash
, hash
);
3572 synchronize_sched();
3573 list_for_each_entry_safe(entry
, p
, &free_list
, free_list
) {
3574 list_del(&entry
->free_list
);
3575 ftrace_free_entry(entry
);
3577 mutex_unlock(&ftrace_lock
);
3580 mutex_unlock(&trace_probe_ops
.func_hash
->regex_lock
);
3581 free_ftrace_hash(hash
);
3585 unregister_ftrace_function_probe(char *glob
, struct ftrace_probe_ops
*ops
,
3588 __unregister_ftrace_function_probe(glob
, ops
, data
,
3589 PROBE_TEST_FUNC
| PROBE_TEST_DATA
);
3593 unregister_ftrace_function_probe_func(char *glob
, struct ftrace_probe_ops
*ops
)
3595 __unregister_ftrace_function_probe(glob
, ops
, NULL
, PROBE_TEST_FUNC
);
3598 void unregister_ftrace_function_probe_all(char *glob
)
3600 __unregister_ftrace_function_probe(glob
, NULL
, NULL
, 0);
3603 static LIST_HEAD(ftrace_commands
);
3604 static DEFINE_MUTEX(ftrace_cmd_mutex
);
3607 * Currently we only register ftrace commands from __init, so mark this
3610 __init
int register_ftrace_command(struct ftrace_func_command
*cmd
)
3612 struct ftrace_func_command
*p
;
3615 mutex_lock(&ftrace_cmd_mutex
);
3616 list_for_each_entry(p
, &ftrace_commands
, list
) {
3617 if (strcmp(cmd
->name
, p
->name
) == 0) {
3622 list_add(&cmd
->list
, &ftrace_commands
);
3624 mutex_unlock(&ftrace_cmd_mutex
);
3630 * Currently we only unregister ftrace commands from __init, so mark
3633 __init
int unregister_ftrace_command(struct ftrace_func_command
*cmd
)
3635 struct ftrace_func_command
*p
, *n
;
3638 mutex_lock(&ftrace_cmd_mutex
);
3639 list_for_each_entry_safe(p
, n
, &ftrace_commands
, list
) {
3640 if (strcmp(cmd
->name
, p
->name
) == 0) {
3642 list_del_init(&p
->list
);
3647 mutex_unlock(&ftrace_cmd_mutex
);
3652 static int ftrace_process_regex(struct ftrace_hash
*hash
,
3653 char *buff
, int len
, int enable
)
3655 char *func
, *command
, *next
= buff
;
3656 struct ftrace_func_command
*p
;
3659 func
= strsep(&next
, ":");
3662 ret
= ftrace_match_records(hash
, func
, len
);
3672 command
= strsep(&next
, ":");
3674 mutex_lock(&ftrace_cmd_mutex
);
3675 list_for_each_entry(p
, &ftrace_commands
, list
) {
3676 if (strcmp(p
->name
, command
) == 0) {
3677 ret
= p
->func(hash
, func
, command
, next
, enable
);
3682 mutex_unlock(&ftrace_cmd_mutex
);
3688 ftrace_regex_write(struct file
*file
, const char __user
*ubuf
,
3689 size_t cnt
, loff_t
*ppos
, int enable
)
3691 struct ftrace_iterator
*iter
;
3692 struct trace_parser
*parser
;
3698 if (file
->f_mode
& FMODE_READ
) {
3699 struct seq_file
*m
= file
->private_data
;
3702 iter
= file
->private_data
;
3704 if (unlikely(ftrace_disabled
))
3707 /* iter->hash is a local copy, so we don't need regex_lock */
3709 parser
= &iter
->parser
;
3710 read
= trace_get_user(parser
, ubuf
, cnt
, ppos
);
3712 if (read
>= 0 && trace_parser_loaded(parser
) &&
3713 !trace_parser_cont(parser
)) {
3714 ret
= ftrace_process_regex(iter
->hash
, parser
->buffer
,
3715 parser
->idx
, enable
);
3716 trace_parser_clear(parser
);
3727 ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
3728 size_t cnt
, loff_t
*ppos
)
3730 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 1);
3734 ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
3735 size_t cnt
, loff_t
*ppos
)
3737 return ftrace_regex_write(file
, ubuf
, cnt
, ppos
, 0);
3741 ftrace_match_addr(struct ftrace_hash
*hash
, unsigned long ip
, int remove
)
3743 struct ftrace_func_entry
*entry
;
3745 if (!ftrace_location(ip
))
3749 entry
= ftrace_lookup_ip(hash
, ip
);
3752 free_hash_entry(hash
, entry
);
3756 return add_hash_entry(hash
, ip
);
3759 static void ftrace_ops_update_code(struct ftrace_ops
*ops
)
3761 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
&& ftrace_enabled
)
3762 ftrace_run_update_code(FTRACE_UPDATE_CALLS
);
3766 ftrace_set_hash(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3767 unsigned long ip
, int remove
, int reset
, int enable
)
3769 struct ftrace_hash
**orig_hash
;
3770 struct ftrace_hash
*hash
;
3773 if (unlikely(ftrace_disabled
))
3776 mutex_lock(&ops
->func_hash
->regex_lock
);
3779 orig_hash
= &ops
->func_hash
->filter_hash
;
3781 orig_hash
= &ops
->func_hash
->notrace_hash
;
3784 hash
= alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
);
3786 hash
= alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS
, *orig_hash
);
3790 goto out_regex_unlock
;
3793 if (buf
&& !ftrace_match_records(hash
, buf
, len
)) {
3795 goto out_regex_unlock
;
3798 ret
= ftrace_match_addr(hash
, ip
, remove
);
3800 goto out_regex_unlock
;
3803 mutex_lock(&ftrace_lock
);
3804 ret
= ftrace_hash_move(ops
, enable
, orig_hash
, hash
);
3806 ftrace_ops_update_code(ops
);
3808 mutex_unlock(&ftrace_lock
);
3811 mutex_unlock(&ops
->func_hash
->regex_lock
);
3813 free_ftrace_hash(hash
);
3818 ftrace_set_addr(struct ftrace_ops
*ops
, unsigned long ip
, int remove
,
3819 int reset
, int enable
)
3821 return ftrace_set_hash(ops
, 0, 0, ip
, remove
, reset
, enable
);
3825 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3826 * @ops - the ops to set the filter with
3827 * @ip - the address to add to or remove from the filter.
3828 * @remove - non zero to remove the ip from the filter
3829 * @reset - non zero to reset all filters before applying this filter.
3831 * Filters denote which functions should be enabled when tracing is enabled
3832 * If @ip is NULL, it failes to update filter.
3834 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
3835 int remove
, int reset
)
3837 ftrace_ops_init(ops
);
3838 return ftrace_set_addr(ops
, ip
, remove
, reset
, 1);
3840 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip
);
3843 ftrace_set_regex(struct ftrace_ops
*ops
, unsigned char *buf
, int len
,
3844 int reset
, int enable
)
3846 return ftrace_set_hash(ops
, buf
, len
, 0, 0, reset
, enable
);
3850 * ftrace_set_filter - set a function to filter on in ftrace
3851 * @ops - the ops to set the filter with
3852 * @buf - the string that holds the function filter text.
3853 * @len - the length of the string.
3854 * @reset - non zero to reset all filters before applying this filter.
3856 * Filters denote which functions should be enabled when tracing is enabled.
3857 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3859 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
3862 ftrace_ops_init(ops
);
3863 return ftrace_set_regex(ops
, buf
, len
, reset
, 1);
3865 EXPORT_SYMBOL_GPL(ftrace_set_filter
);
3868 * ftrace_set_notrace - set a function to not trace in ftrace
3869 * @ops - the ops to set the notrace filter with
3870 * @buf - the string that holds the function notrace text.
3871 * @len - the length of the string.
3872 * @reset - non zero to reset all filters before applying this filter.
3874 * Notrace Filters denote which functions should not be enabled when tracing
3875 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3878 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
3881 ftrace_ops_init(ops
);
3882 return ftrace_set_regex(ops
, buf
, len
, reset
, 0);
3884 EXPORT_SYMBOL_GPL(ftrace_set_notrace
);
3886 * ftrace_set_global_filter - set a function to filter on with global tracers
3887 * @buf - the string that holds the function filter text.
3888 * @len - the length of the string.
3889 * @reset - non zero to reset all filters before applying this filter.
3891 * Filters denote which functions should be enabled when tracing is enabled.
3892 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3894 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
)
3896 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 1);
3898 EXPORT_SYMBOL_GPL(ftrace_set_global_filter
);
3901 * ftrace_set_global_notrace - set a function to not trace with global tracers
3902 * @buf - the string that holds the function notrace text.
3903 * @len - the length of the string.
3904 * @reset - non zero to reset all filters before applying this filter.
3906 * Notrace Filters denote which functions should not be enabled when tracing
3907 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3910 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
)
3912 ftrace_set_regex(&global_ops
, buf
, len
, reset
, 0);
3914 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace
);
3917 * command line interface to allow users to set filters on boot up.
3919 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3920 static char ftrace_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3921 static char ftrace_filter_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3923 /* Used by function selftest to not test if filter is set */
3924 bool ftrace_filter_param __initdata
;
3926 static int __init
set_ftrace_notrace(char *str
)
3928 ftrace_filter_param
= true;
3929 strlcpy(ftrace_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
3932 __setup("ftrace_notrace=", set_ftrace_notrace
);
3934 static int __init
set_ftrace_filter(char *str
)
3936 ftrace_filter_param
= true;
3937 strlcpy(ftrace_filter_buf
, str
, FTRACE_FILTER_SIZE
);
3940 __setup("ftrace_filter=", set_ftrace_filter
);
3942 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
3943 static char ftrace_graph_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3944 static char ftrace_graph_notrace_buf
[FTRACE_FILTER_SIZE
] __initdata
;
3945 static int ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
);
3947 static int __init
set_graph_function(char *str
)
3949 strlcpy(ftrace_graph_buf
, str
, FTRACE_FILTER_SIZE
);
3952 __setup("ftrace_graph_filter=", set_graph_function
);
3954 static int __init
set_graph_notrace_function(char *str
)
3956 strlcpy(ftrace_graph_notrace_buf
, str
, FTRACE_FILTER_SIZE
);
3959 __setup("ftrace_graph_notrace=", set_graph_notrace_function
);
3961 static void __init
set_ftrace_early_graph(char *buf
, int enable
)
3965 unsigned long *table
= ftrace_graph_funcs
;
3966 int *count
= &ftrace_graph_count
;
3969 table
= ftrace_graph_notrace_funcs
;
3970 count
= &ftrace_graph_notrace_count
;
3974 func
= strsep(&buf
, ",");
3975 /* we allow only one expression at a time */
3976 ret
= ftrace_set_func(table
, count
, FTRACE_GRAPH_MAX_FUNCS
, func
);
3978 printk(KERN_DEBUG
"ftrace: function %s not "
3979 "traceable\n", func
);
3982 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3985 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
)
3989 ftrace_ops_init(ops
);
3992 func
= strsep(&buf
, ",");
3993 ftrace_set_regex(ops
, func
, strlen(func
), 0, enable
);
3997 static void __init
set_ftrace_early_filters(void)
3999 if (ftrace_filter_buf
[0])
4000 ftrace_set_early_filter(&global_ops
, ftrace_filter_buf
, 1);
4001 if (ftrace_notrace_buf
[0])
4002 ftrace_set_early_filter(&global_ops
, ftrace_notrace_buf
, 0);
4003 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4004 if (ftrace_graph_buf
[0])
4005 set_ftrace_early_graph(ftrace_graph_buf
, 1);
4006 if (ftrace_graph_notrace_buf
[0])
4007 set_ftrace_early_graph(ftrace_graph_notrace_buf
, 0);
4008 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4011 int ftrace_regex_release(struct inode
*inode
, struct file
*file
)
4013 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
4014 struct ftrace_iterator
*iter
;
4015 struct ftrace_hash
**orig_hash
;
4016 struct trace_parser
*parser
;
4020 if (file
->f_mode
& FMODE_READ
) {
4022 seq_release(inode
, file
);
4024 iter
= file
->private_data
;
4026 parser
= &iter
->parser
;
4027 if (trace_parser_loaded(parser
)) {
4028 parser
->buffer
[parser
->idx
] = 0;
4029 ftrace_match_records(iter
->hash
, parser
->buffer
, parser
->idx
);
4032 trace_parser_put(parser
);
4034 mutex_lock(&iter
->ops
->func_hash
->regex_lock
);
4036 if (file
->f_mode
& FMODE_WRITE
) {
4037 filter_hash
= !!(iter
->flags
& FTRACE_ITER_FILTER
);
4040 orig_hash
= &iter
->ops
->func_hash
->filter_hash
;
4042 orig_hash
= &iter
->ops
->func_hash
->notrace_hash
;
4044 mutex_lock(&ftrace_lock
);
4045 ret
= ftrace_hash_move(iter
->ops
, filter_hash
,
4046 orig_hash
, iter
->hash
);
4048 ftrace_ops_update_code(iter
->ops
);
4050 mutex_unlock(&ftrace_lock
);
4053 mutex_unlock(&iter
->ops
->func_hash
->regex_lock
);
4054 free_ftrace_hash(iter
->hash
);
4060 static const struct file_operations ftrace_avail_fops
= {
4061 .open
= ftrace_avail_open
,
4063 .llseek
= seq_lseek
,
4064 .release
= seq_release_private
,
4067 static const struct file_operations ftrace_enabled_fops
= {
4068 .open
= ftrace_enabled_open
,
4070 .llseek
= seq_lseek
,
4071 .release
= seq_release_private
,
4074 static const struct file_operations ftrace_filter_fops
= {
4075 .open
= ftrace_filter_open
,
4077 .write
= ftrace_filter_write
,
4078 .llseek
= tracing_lseek
,
4079 .release
= ftrace_regex_release
,
4082 static const struct file_operations ftrace_notrace_fops
= {
4083 .open
= ftrace_notrace_open
,
4085 .write
= ftrace_notrace_write
,
4086 .llseek
= tracing_lseek
,
4087 .release
= ftrace_regex_release
,
4090 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4092 static DEFINE_MUTEX(graph_lock
);
4094 int ftrace_graph_count
;
4095 int ftrace_graph_notrace_count
;
4096 unsigned long ftrace_graph_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4097 unsigned long ftrace_graph_notrace_funcs
[FTRACE_GRAPH_MAX_FUNCS
] __read_mostly
;
4099 struct ftrace_graph_data
{
4100 unsigned long *table
;
4103 const struct seq_operations
*seq_ops
;
4107 __g_next(struct seq_file
*m
, loff_t
*pos
)
4109 struct ftrace_graph_data
*fgd
= m
->private;
4111 if (*pos
>= *fgd
->count
)
4113 return &fgd
->table
[*pos
];
4117 g_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4120 return __g_next(m
, pos
);
4123 static void *g_start(struct seq_file
*m
, loff_t
*pos
)
4125 struct ftrace_graph_data
*fgd
= m
->private;
4127 mutex_lock(&graph_lock
);
4129 /* Nothing, tell g_show to print all functions are enabled */
4130 if (!*fgd
->count
&& !*pos
)
4133 return __g_next(m
, pos
);
4136 static void g_stop(struct seq_file
*m
, void *p
)
4138 mutex_unlock(&graph_lock
);
4141 static int g_show(struct seq_file
*m
, void *v
)
4143 unsigned long *ptr
= v
;
4148 if (ptr
== (unsigned long *)1) {
4149 struct ftrace_graph_data
*fgd
= m
->private;
4151 if (fgd
->table
== ftrace_graph_funcs
)
4152 seq_printf(m
, "#### all functions enabled ####\n");
4154 seq_printf(m
, "#### no functions disabled ####\n");
4158 seq_printf(m
, "%ps\n", (void *)*ptr
);
4163 static const struct seq_operations ftrace_graph_seq_ops
= {
4171 __ftrace_graph_open(struct inode
*inode
, struct file
*file
,
4172 struct ftrace_graph_data
*fgd
)
4176 mutex_lock(&graph_lock
);
4177 if ((file
->f_mode
& FMODE_WRITE
) &&
4178 (file
->f_flags
& O_TRUNC
)) {
4180 memset(fgd
->table
, 0, fgd
->size
* sizeof(*fgd
->table
));
4182 mutex_unlock(&graph_lock
);
4184 if (file
->f_mode
& FMODE_READ
) {
4185 ret
= seq_open(file
, fgd
->seq_ops
);
4187 struct seq_file
*m
= file
->private_data
;
4191 file
->private_data
= fgd
;
4197 ftrace_graph_open(struct inode
*inode
, struct file
*file
)
4199 struct ftrace_graph_data
*fgd
;
4201 if (unlikely(ftrace_disabled
))
4204 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4208 fgd
->table
= ftrace_graph_funcs
;
4209 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4210 fgd
->count
= &ftrace_graph_count
;
4211 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4213 return __ftrace_graph_open(inode
, file
, fgd
);
4217 ftrace_graph_notrace_open(struct inode
*inode
, struct file
*file
)
4219 struct ftrace_graph_data
*fgd
;
4221 if (unlikely(ftrace_disabled
))
4224 fgd
= kmalloc(sizeof(*fgd
), GFP_KERNEL
);
4228 fgd
->table
= ftrace_graph_notrace_funcs
;
4229 fgd
->size
= FTRACE_GRAPH_MAX_FUNCS
;
4230 fgd
->count
= &ftrace_graph_notrace_count
;
4231 fgd
->seq_ops
= &ftrace_graph_seq_ops
;
4233 return __ftrace_graph_open(inode
, file
, fgd
);
4237 ftrace_graph_release(struct inode
*inode
, struct file
*file
)
4239 if (file
->f_mode
& FMODE_READ
) {
4240 struct seq_file
*m
= file
->private_data
;
4243 seq_release(inode
, file
);
4245 kfree(file
->private_data
);
4252 ftrace_set_func(unsigned long *array
, int *idx
, int size
, char *buffer
)
4254 struct dyn_ftrace
*rec
;
4255 struct ftrace_page
*pg
;
4264 type
= filter_parse_regex(buffer
, strlen(buffer
), &search
, ¬);
4265 if (!not && *idx
>= size
)
4268 search_len
= strlen(search
);
4270 mutex_lock(&ftrace_lock
);
4272 if (unlikely(ftrace_disabled
)) {
4273 mutex_unlock(&ftrace_lock
);
4277 do_for_each_ftrace_rec(pg
, rec
) {
4279 if (ftrace_match_record(rec
, NULL
, search
, search_len
, type
)) {
4280 /* if it is in the array */
4282 for (i
= 0; i
< *idx
; i
++) {
4283 if (array
[i
] == rec
->ip
) {
4292 array
[(*idx
)++] = rec
->ip
;
4298 array
[i
] = array
[--(*idx
)];
4304 } while_for_each_ftrace_rec();
4306 mutex_unlock(&ftrace_lock
);
4315 ftrace_graph_write(struct file
*file
, const char __user
*ubuf
,
4316 size_t cnt
, loff_t
*ppos
)
4318 struct trace_parser parser
;
4319 ssize_t read
, ret
= 0;
4320 struct ftrace_graph_data
*fgd
= file
->private_data
;
4325 if (trace_parser_get_init(&parser
, FTRACE_BUFF_MAX
))
4328 read
= trace_get_user(&parser
, ubuf
, cnt
, ppos
);
4330 if (read
>= 0 && trace_parser_loaded((&parser
))) {
4331 parser
.buffer
[parser
.idx
] = 0;
4333 mutex_lock(&graph_lock
);
4335 /* we allow only one expression at a time */
4336 ret
= ftrace_set_func(fgd
->table
, fgd
->count
, fgd
->size
,
4339 mutex_unlock(&graph_lock
);
4345 trace_parser_put(&parser
);
4350 static const struct file_operations ftrace_graph_fops
= {
4351 .open
= ftrace_graph_open
,
4353 .write
= ftrace_graph_write
,
4354 .llseek
= tracing_lseek
,
4355 .release
= ftrace_graph_release
,
4358 static const struct file_operations ftrace_graph_notrace_fops
= {
4359 .open
= ftrace_graph_notrace_open
,
4361 .write
= ftrace_graph_write
,
4362 .llseek
= tracing_lseek
,
4363 .release
= ftrace_graph_release
,
4365 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4367 void ftrace_create_filter_files(struct ftrace_ops
*ops
,
4368 struct dentry
*parent
)
4371 trace_create_file("set_ftrace_filter", 0644, parent
,
4372 ops
, &ftrace_filter_fops
);
4374 trace_create_file("set_ftrace_notrace", 0644, parent
,
4375 ops
, &ftrace_notrace_fops
);
4379 * The name "destroy_filter_files" is really a misnomer. Although
4380 * in the future, it may actualy delete the files, but this is
4381 * really intended to make sure the ops passed in are disabled
4382 * and that when this function returns, the caller is free to
4385 * The "destroy" name is only to match the "create" name that this
4386 * should be paired with.
4388 void ftrace_destroy_filter_files(struct ftrace_ops
*ops
)
4390 mutex_lock(&ftrace_lock
);
4391 if (ops
->flags
& FTRACE_OPS_FL_ENABLED
)
4392 ftrace_shutdown(ops
, 0);
4393 ops
->flags
|= FTRACE_OPS_FL_DELETED
;
4394 mutex_unlock(&ftrace_lock
);
4397 static __init
int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
)
4400 trace_create_file("available_filter_functions", 0444,
4401 d_tracer
, NULL
, &ftrace_avail_fops
);
4403 trace_create_file("enabled_functions", 0444,
4404 d_tracer
, NULL
, &ftrace_enabled_fops
);
4406 ftrace_create_filter_files(&global_ops
, d_tracer
);
4408 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4409 trace_create_file("set_graph_function", 0444, d_tracer
,
4411 &ftrace_graph_fops
);
4412 trace_create_file("set_graph_notrace", 0444, d_tracer
,
4414 &ftrace_graph_notrace_fops
);
4415 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4420 static int ftrace_cmp_ips(const void *a
, const void *b
)
4422 const unsigned long *ipa
= a
;
4423 const unsigned long *ipb
= b
;
4432 static void ftrace_swap_ips(void *a
, void *b
, int size
)
4434 unsigned long *ipa
= a
;
4435 unsigned long *ipb
= b
;
4443 static int ftrace_process_locs(struct module
*mod
,
4444 unsigned long *start
,
4447 struct ftrace_page
*start_pg
;
4448 struct ftrace_page
*pg
;
4449 struct dyn_ftrace
*rec
;
4450 unsigned long count
;
4453 unsigned long flags
= 0; /* Shut up gcc */
4456 count
= end
- start
;
4461 sort(start
, count
, sizeof(*start
),
4462 ftrace_cmp_ips
, ftrace_swap_ips
);
4464 start_pg
= ftrace_allocate_pages(count
);
4468 mutex_lock(&ftrace_lock
);
4471 * Core and each module needs their own pages, as
4472 * modules will free them when they are removed.
4473 * Force a new page to be allocated for modules.
4476 WARN_ON(ftrace_pages
|| ftrace_pages_start
);
4477 /* First initialization */
4478 ftrace_pages
= ftrace_pages_start
= start_pg
;
4483 if (WARN_ON(ftrace_pages
->next
)) {
4484 /* Hmm, we have free pages? */
4485 while (ftrace_pages
->next
)
4486 ftrace_pages
= ftrace_pages
->next
;
4489 ftrace_pages
->next
= start_pg
;
4495 addr
= ftrace_call_adjust(*p
++);
4497 * Some architecture linkers will pad between
4498 * the different mcount_loc sections of different
4499 * object files to satisfy alignments.
4500 * Skip any NULL pointers.
4505 if (pg
->index
== pg
->size
) {
4506 /* We should have allocated enough */
4507 if (WARN_ON(!pg
->next
))
4512 rec
= &pg
->records
[pg
->index
++];
4516 /* We should have used all pages */
4519 /* Assign the last page to ftrace_pages */
4523 * We only need to disable interrupts on start up
4524 * because we are modifying code that an interrupt
4525 * may execute, and the modification is not atomic.
4526 * But for modules, nothing runs the code we modify
4527 * until we are finished with it, and there's no
4528 * reason to cause large interrupt latencies while we do it.
4531 local_irq_save(flags
);
4532 ftrace_update_code(mod
, start_pg
);
4534 local_irq_restore(flags
);
4537 mutex_unlock(&ftrace_lock
);
4542 #ifdef CONFIG_MODULES
4544 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4546 void ftrace_release_mod(struct module
*mod
)
4548 struct dyn_ftrace
*rec
;
4549 struct ftrace_page
**last_pg
;
4550 struct ftrace_page
*pg
;
4553 mutex_lock(&ftrace_lock
);
4555 if (ftrace_disabled
)
4559 * Each module has its own ftrace_pages, remove
4560 * them from the list.
4562 last_pg
= &ftrace_pages_start
;
4563 for (pg
= ftrace_pages_start
; pg
; pg
= *last_pg
) {
4564 rec
= &pg
->records
[0];
4565 if (within_module_core(rec
->ip
, mod
)) {
4567 * As core pages are first, the first
4568 * page should never be a module page.
4570 if (WARN_ON(pg
== ftrace_pages_start
))
4573 /* Check if we are deleting the last page */
4574 if (pg
== ftrace_pages
)
4575 ftrace_pages
= next_to_ftrace_page(last_pg
);
4577 *last_pg
= pg
->next
;
4578 order
= get_count_order(pg
->size
/ ENTRIES_PER_PAGE
);
4579 free_pages((unsigned long)pg
->records
, order
);
4582 last_pg
= &pg
->next
;
4585 mutex_unlock(&ftrace_lock
);
4588 static void ftrace_init_module(struct module
*mod
,
4589 unsigned long *start
, unsigned long *end
)
4591 if (ftrace_disabled
|| start
== end
)
4593 ftrace_process_locs(mod
, start
, end
);
4596 void ftrace_module_init(struct module
*mod
)
4598 ftrace_init_module(mod
, mod
->ftrace_callsites
,
4599 mod
->ftrace_callsites
+
4600 mod
->num_ftrace_callsites
);
4603 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4604 unsigned long val
, void *data
)
4606 struct module
*mod
= data
;
4608 if (val
== MODULE_STATE_GOING
)
4609 ftrace_release_mod(mod
);
4614 static int ftrace_module_notify_exit(struct notifier_block
*self
,
4615 unsigned long val
, void *data
)
4619 #endif /* CONFIG_MODULES */
4621 struct notifier_block ftrace_module_exit_nb
= {
4622 .notifier_call
= ftrace_module_notify_exit
,
4623 .priority
= INT_MIN
, /* Run after anything that can remove kprobes */
4626 void __init
ftrace_init(void)
4628 extern unsigned long __start_mcount_loc
[];
4629 extern unsigned long __stop_mcount_loc
[];
4630 unsigned long count
, flags
;
4633 local_irq_save(flags
);
4634 ret
= ftrace_dyn_arch_init();
4635 local_irq_restore(flags
);
4639 count
= __stop_mcount_loc
- __start_mcount_loc
;
4641 pr_info("ftrace: No functions to be traced?\n");
4645 pr_info("ftrace: allocating %ld entries in %ld pages\n",
4646 count
, count
/ ENTRIES_PER_PAGE
+ 1);
4648 last_ftrace_enabled
= ftrace_enabled
= 1;
4650 ret
= ftrace_process_locs(NULL
,
4654 ret
= register_module_notifier(&ftrace_module_exit_nb
);
4656 pr_warning("Failed to register trace ftrace module exit notifier\n");
4658 set_ftrace_early_filters();
4662 ftrace_disabled
= 1;
4667 static struct ftrace_ops global_ops
= {
4668 .func
= ftrace_stub
,
4669 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4672 static int __init
ftrace_nodyn_init(void)
4677 core_initcall(ftrace_nodyn_init
);
4679 static inline int ftrace_init_dyn_debugfs(struct dentry
*d_tracer
) { return 0; }
4680 static inline void ftrace_startup_enable(int command
) { }
4681 /* Keep as macros so we do not need to define the commands */
4682 # define ftrace_startup(ops, command) \
4684 int ___ret = __register_ftrace_function(ops); \
4686 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4689 # define ftrace_shutdown(ops, command) \
4691 int ___ret = __unregister_ftrace_function(ops); \
4693 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
4697 # define ftrace_startup_sysctl() do { } while (0)
4698 # define ftrace_shutdown_sysctl() do { } while (0)
4701 ftrace_ops_test(struct ftrace_ops
*ops
, unsigned long ip
, void *regs
)
4706 #endif /* CONFIG_DYNAMIC_FTRACE */
4708 __init
void ftrace_init_global_array_ops(struct trace_array
*tr
)
4710 tr
->ops
= &global_ops
;
4711 tr
->ops
->private = tr
;
4714 void ftrace_init_array_ops(struct trace_array
*tr
, ftrace_func_t func
)
4716 /* If we filter on pids, update to use the pid function */
4717 if (tr
->flags
& TRACE_ARRAY_FL_GLOBAL
) {
4718 if (WARN_ON(tr
->ops
->func
!= ftrace_stub
))
4719 printk("ftrace ops had %pS for function\n",
4721 /* Only the top level instance does pid tracing */
4722 if (!list_empty(&ftrace_pids
)) {
4723 set_ftrace_pid_function(func
);
4724 func
= ftrace_pid_func
;
4727 tr
->ops
->func
= func
;
4728 tr
->ops
->private = tr
;
4731 void ftrace_reset_array_ops(struct trace_array
*tr
)
4733 tr
->ops
->func
= ftrace_stub
;
4737 ftrace_ops_control_func(unsigned long ip
, unsigned long parent_ip
,
4738 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4740 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT
)))
4744 * Some of the ops may be dynamically allocated,
4745 * they must be freed after a synchronize_sched().
4747 preempt_disable_notrace();
4748 trace_recursion_set(TRACE_CONTROL_BIT
);
4751 * Control funcs (perf) uses RCU. Only trace if
4752 * RCU is currently active.
4754 if (!rcu_is_watching())
4757 do_for_each_ftrace_op(op
, ftrace_control_list
) {
4758 if (!(op
->flags
& FTRACE_OPS_FL_STUB
) &&
4759 !ftrace_function_local_disabled(op
) &&
4760 ftrace_ops_test(op
, ip
, regs
))
4761 op
->func(ip
, parent_ip
, op
, regs
);
4762 } while_for_each_ftrace_op(op
);
4764 trace_recursion_clear(TRACE_CONTROL_BIT
);
4765 preempt_enable_notrace();
4768 static struct ftrace_ops control_ops
= {
4769 .func
= ftrace_ops_control_func
,
4770 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
| FTRACE_OPS_FL_INITIALIZED
,
4771 INIT_OPS_HASH(control_ops
)
4775 __ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4776 struct ftrace_ops
*ignored
, struct pt_regs
*regs
)
4778 struct ftrace_ops
*op
;
4781 bit
= trace_test_and_set_recursion(TRACE_LIST_START
, TRACE_LIST_MAX
);
4786 * Some of the ops may be dynamically allocated,
4787 * they must be freed after a synchronize_sched().
4789 preempt_disable_notrace();
4790 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
4791 if (ftrace_ops_test(op
, ip
, regs
)) {
4792 if (FTRACE_WARN_ON(!op
->func
)) {
4793 pr_warn("op=%p %pS\n", op
, op
);
4796 op
->func(ip
, parent_ip
, op
, regs
);
4798 } while_for_each_ftrace_op(op
);
4800 preempt_enable_notrace();
4801 trace_clear_recursion(bit
);
4805 * Some archs only support passing ip and parent_ip. Even though
4806 * the list function ignores the op parameter, we do not want any
4807 * C side effects, where a function is called without the caller
4808 * sending a third parameter.
4809 * Archs are to support both the regs and ftrace_ops at the same time.
4810 * If they support ftrace_ops, it is assumed they support regs.
4811 * If call backs want to use regs, they must either check for regs
4812 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4813 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
4814 * An architecture can pass partial regs with ftrace_ops and still
4815 * set the ARCH_SUPPORT_FTARCE_OPS.
4817 #if ARCH_SUPPORTS_FTRACE_OPS
4818 static void ftrace_ops_list_func(unsigned long ip
, unsigned long parent_ip
,
4819 struct ftrace_ops
*op
, struct pt_regs
*regs
)
4821 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, regs
);
4824 static void ftrace_ops_no_ops(unsigned long ip
, unsigned long parent_ip
)
4826 __ftrace_ops_list_func(ip
, parent_ip
, NULL
, NULL
);
4830 static void clear_ftrace_swapper(void)
4832 struct task_struct
*p
;
4836 for_each_online_cpu(cpu
) {
4838 clear_tsk_trace_trace(p
);
4843 static void set_ftrace_swapper(void)
4845 struct task_struct
*p
;
4849 for_each_online_cpu(cpu
) {
4851 set_tsk_trace_trace(p
);
4856 static void clear_ftrace_pid(struct pid
*pid
)
4858 struct task_struct
*p
;
4861 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4862 clear_tsk_trace_trace(p
);
4863 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4869 static void set_ftrace_pid(struct pid
*pid
)
4871 struct task_struct
*p
;
4874 do_each_pid_task(pid
, PIDTYPE_PID
, p
) {
4875 set_tsk_trace_trace(p
);
4876 } while_each_pid_task(pid
, PIDTYPE_PID
, p
);
4880 static void clear_ftrace_pid_task(struct pid
*pid
)
4882 if (pid
== ftrace_swapper_pid
)
4883 clear_ftrace_swapper();
4885 clear_ftrace_pid(pid
);
4888 static void set_ftrace_pid_task(struct pid
*pid
)
4890 if (pid
== ftrace_swapper_pid
)
4891 set_ftrace_swapper();
4893 set_ftrace_pid(pid
);
4896 static int ftrace_pid_add(int p
)
4899 struct ftrace_pid
*fpid
;
4902 mutex_lock(&ftrace_lock
);
4905 pid
= ftrace_swapper_pid
;
4907 pid
= find_get_pid(p
);
4914 list_for_each_entry(fpid
, &ftrace_pids
, list
)
4915 if (fpid
->pid
== pid
)
4920 fpid
= kmalloc(sizeof(*fpid
), GFP_KERNEL
);
4924 list_add(&fpid
->list
, &ftrace_pids
);
4927 set_ftrace_pid_task(pid
);
4929 ftrace_update_pid_func();
4930 ftrace_startup_enable(0);
4932 mutex_unlock(&ftrace_lock
);
4936 if (pid
!= ftrace_swapper_pid
)
4940 mutex_unlock(&ftrace_lock
);
4944 static void ftrace_pid_reset(void)
4946 struct ftrace_pid
*fpid
, *safe
;
4948 mutex_lock(&ftrace_lock
);
4949 list_for_each_entry_safe(fpid
, safe
, &ftrace_pids
, list
) {
4950 struct pid
*pid
= fpid
->pid
;
4952 clear_ftrace_pid_task(pid
);
4954 list_del(&fpid
->list
);
4958 ftrace_update_pid_func();
4959 ftrace_startup_enable(0);
4961 mutex_unlock(&ftrace_lock
);
4964 static void *fpid_start(struct seq_file
*m
, loff_t
*pos
)
4966 mutex_lock(&ftrace_lock
);
4968 if (list_empty(&ftrace_pids
) && (!*pos
))
4971 return seq_list_start(&ftrace_pids
, *pos
);
4974 static void *fpid_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
4979 return seq_list_next(v
, &ftrace_pids
, pos
);
4982 static void fpid_stop(struct seq_file
*m
, void *p
)
4984 mutex_unlock(&ftrace_lock
);
4987 static int fpid_show(struct seq_file
*m
, void *v
)
4989 const struct ftrace_pid
*fpid
= list_entry(v
, struct ftrace_pid
, list
);
4991 if (v
== (void *)1) {
4992 seq_printf(m
, "no pid\n");
4996 if (fpid
->pid
== ftrace_swapper_pid
)
4997 seq_printf(m
, "swapper tasks\n");
4999 seq_printf(m
, "%u\n", pid_vnr(fpid
->pid
));
5004 static const struct seq_operations ftrace_pid_sops
= {
5005 .start
= fpid_start
,
5012 ftrace_pid_open(struct inode
*inode
, struct file
*file
)
5016 if ((file
->f_mode
& FMODE_WRITE
) &&
5017 (file
->f_flags
& O_TRUNC
))
5020 if (file
->f_mode
& FMODE_READ
)
5021 ret
= seq_open(file
, &ftrace_pid_sops
);
5027 ftrace_pid_write(struct file
*filp
, const char __user
*ubuf
,
5028 size_t cnt
, loff_t
*ppos
)
5034 if (cnt
>= sizeof(buf
))
5037 if (copy_from_user(&buf
, ubuf
, cnt
))
5043 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
5044 * to clean the filter quietly.
5046 tmp
= strstrip(buf
);
5047 if (strlen(tmp
) == 0)
5050 ret
= kstrtol(tmp
, 10, &val
);
5054 ret
= ftrace_pid_add(val
);
5056 return ret
? ret
: cnt
;
5060 ftrace_pid_release(struct inode
*inode
, struct file
*file
)
5062 if (file
->f_mode
& FMODE_READ
)
5063 seq_release(inode
, file
);
5068 static const struct file_operations ftrace_pid_fops
= {
5069 .open
= ftrace_pid_open
,
5070 .write
= ftrace_pid_write
,
5072 .llseek
= tracing_lseek
,
5073 .release
= ftrace_pid_release
,
5076 static __init
int ftrace_init_debugfs(void)
5078 struct dentry
*d_tracer
;
5080 d_tracer
= tracing_init_dentry();
5084 ftrace_init_dyn_debugfs(d_tracer
);
5086 trace_create_file("set_ftrace_pid", 0644, d_tracer
,
5087 NULL
, &ftrace_pid_fops
);
5089 ftrace_profile_debugfs(d_tracer
);
5093 fs_initcall(ftrace_init_debugfs
);
5096 * ftrace_kill - kill ftrace
5098 * This function should be used by panic code. It stops ftrace
5099 * but in a not so nice way. If you need to simply kill ftrace
5100 * from a non-atomic section, use ftrace_kill.
5102 void ftrace_kill(void)
5104 ftrace_disabled
= 1;
5106 clear_ftrace_function();
5110 * Test if ftrace is dead or not.
5112 int ftrace_is_dead(void)
5114 return ftrace_disabled
;
5118 * register_ftrace_function - register a function for profiling
5119 * @ops - ops structure that holds the function for profiling.
5121 * Register a function to be called by all functions in the
5124 * Note: @ops->func and all the functions it calls must be labeled
5125 * with "notrace", otherwise it will go into a
5128 int register_ftrace_function(struct ftrace_ops
*ops
)
5132 ftrace_ops_init(ops
);
5134 mutex_lock(&ftrace_lock
);
5136 ret
= ftrace_startup(ops
, 0);
5138 mutex_unlock(&ftrace_lock
);
5142 EXPORT_SYMBOL_GPL(register_ftrace_function
);
5145 * unregister_ftrace_function - unregister a function for profiling.
5146 * @ops - ops structure that holds the function to unregister
5148 * Unregister a function that was added to be called by ftrace profiling.
5150 int unregister_ftrace_function(struct ftrace_ops
*ops
)
5154 mutex_lock(&ftrace_lock
);
5155 ret
= ftrace_shutdown(ops
, 0);
5156 mutex_unlock(&ftrace_lock
);
5160 EXPORT_SYMBOL_GPL(unregister_ftrace_function
);
5163 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
5164 void __user
*buffer
, size_t *lenp
,
5169 mutex_lock(&ftrace_lock
);
5171 if (unlikely(ftrace_disabled
))
5174 ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
5176 if (ret
|| !write
|| (last_ftrace_enabled
== !!ftrace_enabled
))
5179 last_ftrace_enabled
= !!ftrace_enabled
;
5181 if (ftrace_enabled
) {
5183 ftrace_startup_sysctl();
5185 /* we are starting ftrace again */
5186 if (ftrace_ops_list
!= &ftrace_list_end
)
5187 update_ftrace_function();
5190 /* stopping ftrace calls (just send to ftrace_stub) */
5191 ftrace_trace_function
= ftrace_stub
;
5193 ftrace_shutdown_sysctl();
5197 mutex_unlock(&ftrace_lock
);
5201 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5203 static struct ftrace_ops graph_ops
= {
5204 .func
= ftrace_stub
,
5205 .flags
= FTRACE_OPS_FL_RECURSION_SAFE
|
5206 FTRACE_OPS_FL_INITIALIZED
|
5208 #ifdef FTRACE_GRAPH_TRAMP_ADDR
5209 .trampoline
= FTRACE_GRAPH_TRAMP_ADDR
,
5211 ASSIGN_OPS_HASH(graph_ops
, &global_ops
.local_hash
)
5214 static int ftrace_graph_active
;
5216 int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
)
5221 /* The callbacks that hook a function */
5222 trace_func_graph_ret_t ftrace_graph_return
=
5223 (trace_func_graph_ret_t
)ftrace_stub
;
5224 trace_func_graph_ent_t ftrace_graph_entry
= ftrace_graph_entry_stub
;
5225 static trace_func_graph_ent_t __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5227 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5228 static int alloc_retstack_tasklist(struct ftrace_ret_stack
**ret_stack_list
)
5232 unsigned long flags
;
5233 int start
= 0, end
= FTRACE_RETSTACK_ALLOC_SIZE
;
5234 struct task_struct
*g
, *t
;
5236 for (i
= 0; i
< FTRACE_RETSTACK_ALLOC_SIZE
; i
++) {
5237 ret_stack_list
[i
] = kmalloc(FTRACE_RETFUNC_DEPTH
5238 * sizeof(struct ftrace_ret_stack
),
5240 if (!ret_stack_list
[i
]) {
5248 read_lock_irqsave(&tasklist_lock
, flags
);
5249 do_each_thread(g
, t
) {
5255 if (t
->ret_stack
== NULL
) {
5256 atomic_set(&t
->tracing_graph_pause
, 0);
5257 atomic_set(&t
->trace_overrun
, 0);
5258 t
->curr_ret_stack
= -1;
5259 /* Make sure the tasks see the -1 first: */
5261 t
->ret_stack
= ret_stack_list
[start
++];
5263 } while_each_thread(g
, t
);
5266 read_unlock_irqrestore(&tasklist_lock
, flags
);
5268 for (i
= start
; i
< end
; i
++)
5269 kfree(ret_stack_list
[i
]);
5274 ftrace_graph_probe_sched_switch(void *ignore
,
5275 struct task_struct
*prev
, struct task_struct
*next
)
5277 unsigned long long timestamp
;
5281 * Does the user want to count the time a function was asleep.
5282 * If so, do not update the time stamps.
5284 if (trace_flags
& TRACE_ITER_SLEEP_TIME
)
5287 timestamp
= trace_clock_local();
5289 prev
->ftrace_timestamp
= timestamp
;
5291 /* only process tasks that we timestamped */
5292 if (!next
->ftrace_timestamp
)
5296 * Update all the counters in next to make up for the
5297 * time next was sleeping.
5299 timestamp
-= next
->ftrace_timestamp
;
5301 for (index
= next
->curr_ret_stack
; index
>= 0; index
--)
5302 next
->ret_stack
[index
].calltime
+= timestamp
;
5305 /* Allocate a return stack for each task */
5306 static int start_graph_tracing(void)
5308 struct ftrace_ret_stack
**ret_stack_list
;
5311 ret_stack_list
= kmalloc(FTRACE_RETSTACK_ALLOC_SIZE
*
5312 sizeof(struct ftrace_ret_stack
*),
5315 if (!ret_stack_list
)
5318 /* The cpu_boot init_task->ret_stack will never be freed */
5319 for_each_online_cpu(cpu
) {
5320 if (!idle_task(cpu
)->ret_stack
)
5321 ftrace_graph_init_idle_task(idle_task(cpu
), cpu
);
5325 ret
= alloc_retstack_tasklist(ret_stack_list
);
5326 } while (ret
== -EAGAIN
);
5329 ret
= register_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5331 pr_info("ftrace_graph: Couldn't activate tracepoint"
5332 " probe to kernel_sched_switch\n");
5335 kfree(ret_stack_list
);
5340 * Hibernation protection.
5341 * The state of the current task is too much unstable during
5342 * suspend/restore to disk. We want to protect against that.
5345 ftrace_suspend_notifier_call(struct notifier_block
*bl
, unsigned long state
,
5349 case PM_HIBERNATION_PREPARE
:
5350 pause_graph_tracing();
5353 case PM_POST_HIBERNATION
:
5354 unpause_graph_tracing();
5360 static int ftrace_graph_entry_test(struct ftrace_graph_ent
*trace
)
5362 if (!ftrace_ops_test(&global_ops
, trace
->func
, NULL
))
5364 return __ftrace_graph_entry(trace
);
5368 * The function graph tracer should only trace the functions defined
5369 * by set_ftrace_filter and set_ftrace_notrace. If another function
5370 * tracer ops is registered, the graph tracer requires testing the
5371 * function against the global ops, and not just trace any function
5372 * that any ftrace_ops registered.
5374 static void update_function_graph_func(void)
5376 struct ftrace_ops
*op
;
5377 bool do_test
= false;
5380 * The graph and global ops share the same set of functions
5381 * to test. If any other ops is on the list, then
5382 * the graph tracing needs to test if its the function
5385 do_for_each_ftrace_op(op
, ftrace_ops_list
) {
5386 if (op
!= &global_ops
&& op
!= &graph_ops
&&
5387 op
!= &ftrace_list_end
) {
5389 /* in double loop, break out with goto */
5392 } while_for_each_ftrace_op(op
);
5395 ftrace_graph_entry
= ftrace_graph_entry_test
;
5397 ftrace_graph_entry
= __ftrace_graph_entry
;
5400 static struct notifier_block ftrace_suspend_notifier
= {
5401 .notifier_call
= ftrace_suspend_notifier_call
,
5404 int register_ftrace_graph(trace_func_graph_ret_t retfunc
,
5405 trace_func_graph_ent_t entryfunc
)
5409 mutex_lock(&ftrace_lock
);
5411 /* we currently allow only one tracer registered at a time */
5412 if (ftrace_graph_active
) {
5417 register_pm_notifier(&ftrace_suspend_notifier
);
5419 ftrace_graph_active
++;
5420 ret
= start_graph_tracing();
5422 ftrace_graph_active
--;
5426 ftrace_graph_return
= retfunc
;
5429 * Update the indirect function to the entryfunc, and the
5430 * function that gets called to the entry_test first. Then
5431 * call the update fgraph entry function to determine if
5432 * the entryfunc should be called directly or not.
5434 __ftrace_graph_entry
= entryfunc
;
5435 ftrace_graph_entry
= ftrace_graph_entry_test
;
5436 update_function_graph_func();
5438 ret
= ftrace_startup(&graph_ops
, FTRACE_START_FUNC_RET
);
5441 mutex_unlock(&ftrace_lock
);
5445 void unregister_ftrace_graph(void)
5447 mutex_lock(&ftrace_lock
);
5449 if (unlikely(!ftrace_graph_active
))
5452 ftrace_graph_active
--;
5453 ftrace_graph_return
= (trace_func_graph_ret_t
)ftrace_stub
;
5454 ftrace_graph_entry
= ftrace_graph_entry_stub
;
5455 __ftrace_graph_entry
= ftrace_graph_entry_stub
;
5456 ftrace_shutdown(&graph_ops
, FTRACE_STOP_FUNC_RET
);
5457 unregister_pm_notifier(&ftrace_suspend_notifier
);
5458 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch
, NULL
);
5461 mutex_unlock(&ftrace_lock
);
5464 static DEFINE_PER_CPU(struct ftrace_ret_stack
*, idle_ret_stack
);
5467 graph_init_task(struct task_struct
*t
, struct ftrace_ret_stack
*ret_stack
)
5469 atomic_set(&t
->tracing_graph_pause
, 0);
5470 atomic_set(&t
->trace_overrun
, 0);
5471 t
->ftrace_timestamp
= 0;
5472 /* make curr_ret_stack visible before we add the ret_stack */
5474 t
->ret_stack
= ret_stack
;
5478 * Allocate a return stack for the idle task. May be the first
5479 * time through, or it may be done by CPU hotplug online.
5481 void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
)
5483 t
->curr_ret_stack
= -1;
5485 * The idle task has no parent, it either has its own
5486 * stack or no stack at all.
5489 WARN_ON(t
->ret_stack
!= per_cpu(idle_ret_stack
, cpu
));
5491 if (ftrace_graph_active
) {
5492 struct ftrace_ret_stack
*ret_stack
;
5494 ret_stack
= per_cpu(idle_ret_stack
, cpu
);
5496 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5497 * sizeof(struct ftrace_ret_stack
),
5501 per_cpu(idle_ret_stack
, cpu
) = ret_stack
;
5503 graph_init_task(t
, ret_stack
);
5507 /* Allocate a return stack for newly created task */
5508 void ftrace_graph_init_task(struct task_struct
*t
)
5510 /* Make sure we do not use the parent ret_stack */
5511 t
->ret_stack
= NULL
;
5512 t
->curr_ret_stack
= -1;
5514 if (ftrace_graph_active
) {
5515 struct ftrace_ret_stack
*ret_stack
;
5517 ret_stack
= kmalloc(FTRACE_RETFUNC_DEPTH
5518 * sizeof(struct ftrace_ret_stack
),
5522 graph_init_task(t
, ret_stack
);
5526 void ftrace_graph_exit_task(struct task_struct
*t
)
5528 struct ftrace_ret_stack
*ret_stack
= t
->ret_stack
;
5530 t
->ret_stack
= NULL
;
5531 /* NULL must become visible to IRQs before we free it: */