2 * Ftrace header. For implementation details beyond the random comments
3 * scattered below, see: Documentation/trace/ftrace-design.txt
6 #ifndef _LINUX_FTRACE_H
7 #define _LINUX_FTRACE_H
9 #include <linux/trace_clock.h>
10 #include <linux/kallsyms.h>
11 #include <linux/linkage.h>
12 #include <linux/bitops.h>
13 #include <linux/ktime.h>
14 #include <linux/sched.h>
15 #include <linux/types.h>
16 #include <linux/init.h>
19 #include <asm/ftrace.h>
22 * If the arch supports passing the variable contents of
23 * function_trace_op as the third parameter back from the
24 * mcount call, then the arch should define this as 1.
26 #ifndef ARCH_SUPPORTS_FTRACE_OPS
27 #define ARCH_SUPPORTS_FTRACE_OPS 0
31 * If the arch's mcount caller does not support all of ftrace's
32 * features, then it must call an indirect function that
33 * does. Or at least does enough to prevent any unwelcomed side effects.
35 #if !defined(CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST) || \
36 !ARCH_SUPPORTS_FTRACE_OPS
37 # define FTRACE_FORCE_LIST_FUNC 1
39 # define FTRACE_FORCE_LIST_FUNC 0
46 #ifdef CONFIG_FUNCTION_TRACER
48 extern int ftrace_enabled;
50 ftrace_enable_sysctl(struct ctl_table *table, int write,
51 void __user *buffer, size_t *lenp,
56 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
57 struct ftrace_ops *op);
60 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
61 * set in the flags member.
63 * ENABLED - set/unset when ftrace_ops is registered/unregistered
64 * GLOBAL - set manualy by ftrace_ops user to denote the ftrace_ops
65 * is part of the global tracers sharing the same filter
66 * via set_ftrace_* debugfs files.
67 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
68 * allocated ftrace_ops which need special care
69 * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
70 * could be controled by following calls:
71 * ftrace_function_local_enable
72 * ftrace_function_local_disable
75 FTRACE_OPS_FL_ENABLED = 1 << 0,
76 FTRACE_OPS_FL_GLOBAL = 1 << 1,
77 FTRACE_OPS_FL_DYNAMIC = 1 << 2,
78 FTRACE_OPS_FL_CONTROL = 1 << 3,
83 struct ftrace_ops *next;
85 int __percpu *disabled;
86 #ifdef CONFIG_DYNAMIC_FTRACE
87 struct ftrace_hash *notrace_hash;
88 struct ftrace_hash *filter_hash;
92 extern int function_trace_stop;
95 * Type of the current tracing.
97 enum ftrace_tracing_type_t {
98 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
99 FTRACE_TYPE_RETURN, /* Hook the return of the function */
102 /* Current tracing type, default is FTRACE_TYPE_ENTER */
103 extern enum ftrace_tracing_type_t ftrace_tracing_type;
106 * ftrace_stop - stop function tracer.
108 * A quick way to stop the function tracer. Note this an on off switch,
109 * it is not something that is recursive like preempt_disable.
110 * This does not disable the calling of mcount, it only stops the
111 * calling of functions from mcount.
113 static inline void ftrace_stop(void)
115 function_trace_stop = 1;
119 * ftrace_start - start the function tracer.
121 * This function is the inverse of ftrace_stop. This does not enable
122 * the function tracing if the function tracer is disabled. This only
123 * sets the function tracer flag to continue calling the functions
126 static inline void ftrace_start(void)
128 function_trace_stop = 0;
132 * The ftrace_ops must be a static and should also
133 * be read_mostly. These functions do modify read_mostly variables
134 * so use them sparely. Never free an ftrace_op or modify the
135 * next pointer after it has been registered. Even after unregistering
136 * it, the next pointer may still be used internally.
138 int register_ftrace_function(struct ftrace_ops *ops);
139 int unregister_ftrace_function(struct ftrace_ops *ops);
140 void clear_ftrace_function(void);
143 * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
145 * This function enables tracing on current cpu by decreasing
146 * the per cpu control variable.
147 * It must be called with preemption disabled and only on ftrace_ops
148 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
149 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
151 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
153 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
156 (*this_cpu_ptr(ops->disabled))--;
160 * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
162 * This function enables tracing on current cpu by decreasing
163 * the per cpu control variable.
164 * It must be called with preemption disabled and only on ftrace_ops
165 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
166 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
168 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
170 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
173 (*this_cpu_ptr(ops->disabled))++;
177 * ftrace_function_local_disabled - returns ftrace_ops disabled value
180 * This function returns value of ftrace_ops::disabled on current cpu.
181 * It must be called with preemption disabled and only on ftrace_ops
182 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
183 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
185 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
187 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
188 return *this_cpu_ptr(ops->disabled);
191 extern void ftrace_stub(unsigned long a0, unsigned long a1, struct ftrace_ops *op);
193 #else /* !CONFIG_FUNCTION_TRACER */
195 * (un)register_ftrace_function must be a macro since the ops parameter
196 * must not be evaluated.
198 #define register_ftrace_function(ops) ({ 0; })
199 #define unregister_ftrace_function(ops) ({ 0; })
200 static inline void clear_ftrace_function(void) { }
201 static inline void ftrace_kill(void) { }
202 static inline void ftrace_stop(void) { }
203 static inline void ftrace_start(void) { }
204 #endif /* CONFIG_FUNCTION_TRACER */
206 #ifdef CONFIG_STACK_TRACER
207 extern int stack_tracer_enabled;
209 stack_trace_sysctl(struct ctl_table *table, int write,
210 void __user *buffer, size_t *lenp,
214 struct ftrace_func_command {
215 struct list_head list;
217 int (*func)(struct ftrace_hash *hash,
218 char *func, char *cmd,
219 char *params, int enable);
222 #ifdef CONFIG_DYNAMIC_FTRACE
224 int ftrace_arch_code_modify_prepare(void);
225 int ftrace_arch_code_modify_post_process(void);
227 void ftrace_bug(int err, unsigned long ip);
231 struct ftrace_probe_ops {
232 void (*func)(unsigned long ip,
233 unsigned long parent_ip,
235 int (*callback)(unsigned long ip, void **data);
236 void (*free)(void **data);
237 int (*print)(struct seq_file *m,
239 struct ftrace_probe_ops *ops,
244 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
247 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
250 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
251 extern void unregister_ftrace_function_probe_all(char *glob);
253 extern int ftrace_text_reserved(void *start, void *end);
256 FTRACE_FL_ENABLED = (1 << 30),
259 #define FTRACE_FL_MASK (0x3UL << 30)
260 #define FTRACE_REF_MAX ((1 << 30) - 1)
264 unsigned long ip; /* address of mcount call-site */
265 struct dyn_ftrace *freelist;
268 struct dyn_arch_ftrace arch;
271 int ftrace_force_update(void);
272 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
274 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
276 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
277 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
278 void ftrace_free_filter(struct ftrace_ops *ops);
280 int register_ftrace_command(struct ftrace_func_command *cmd);
281 int unregister_ftrace_command(struct ftrace_func_command *cmd);
284 FTRACE_UPDATE_CALLS = (1 << 0),
285 FTRACE_DISABLE_CALLS = (1 << 1),
286 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
287 FTRACE_START_FUNC_RET = (1 << 3),
288 FTRACE_STOP_FUNC_RET = (1 << 4),
292 FTRACE_UPDATE_IGNORE,
293 FTRACE_UPDATE_MAKE_CALL,
294 FTRACE_UPDATE_MAKE_NOP,
298 FTRACE_ITER_FILTER = (1 << 0),
299 FTRACE_ITER_NOTRACE = (1 << 1),
300 FTRACE_ITER_PRINTALL = (1 << 2),
301 FTRACE_ITER_DO_HASH = (1 << 3),
302 FTRACE_ITER_HASH = (1 << 4),
303 FTRACE_ITER_ENABLED = (1 << 5),
306 void arch_ftrace_update_code(int command);
308 struct ftrace_rec_iter;
310 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
311 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
312 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
314 #define for_ftrace_rec_iter(iter) \
315 for (iter = ftrace_rec_iter_start(); \
317 iter = ftrace_rec_iter_next(iter))
320 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
321 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
322 void ftrace_run_stop_machine(int command);
323 unsigned long ftrace_location(unsigned long ip);
325 extern ftrace_func_t ftrace_trace_function;
327 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
328 struct inode *inode, struct file *file);
329 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
330 size_t cnt, loff_t *ppos);
331 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
332 size_t cnt, loff_t *ppos);
333 loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin);
334 int ftrace_regex_release(struct inode *inode, struct file *file);
337 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
339 /* defined in arch */
340 extern int ftrace_ip_converted(unsigned long ip);
341 extern int ftrace_dyn_arch_init(void *data);
342 extern void ftrace_replace_code(int enable);
343 extern int ftrace_update_ftrace_func(ftrace_func_t func);
344 extern void ftrace_caller(void);
345 extern void ftrace_call(void);
346 extern void mcount_call(void);
348 void ftrace_modify_all_code(int command);
351 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
353 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
354 extern void ftrace_graph_caller(void);
355 extern int ftrace_enable_ftrace_graph_caller(void);
356 extern int ftrace_disable_ftrace_graph_caller(void);
358 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
359 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
363 * ftrace_make_nop - convert code into nop
364 * @mod: module structure if called by module load initialization
365 * @rec: the mcount call site record
366 * @addr: the address that the call site should be calling
368 * This is a very sensitive operation and great care needs
369 * to be taken by the arch. The operation should carefully
370 * read the location, check to see if what is read is indeed
371 * what we expect it to be, and then on success of the compare,
372 * it should write to the location.
374 * The code segment at @rec->ip should be a caller to @addr
378 * -EFAULT on error reading the location
379 * -EINVAL on a failed compare of the contents
380 * -EPERM on error writing to the location
381 * Any other value will be considered a failure.
383 extern int ftrace_make_nop(struct module *mod,
384 struct dyn_ftrace *rec, unsigned long addr);
387 * ftrace_make_call - convert a nop call site into a call to addr
388 * @rec: the mcount call site record
389 * @addr: the address that the call site should call
391 * This is a very sensitive operation and great care needs
392 * to be taken by the arch. The operation should carefully
393 * read the location, check to see if what is read is indeed
394 * what we expect it to be, and then on success of the compare,
395 * it should write to the location.
397 * The code segment at @rec->ip should be a nop
401 * -EFAULT on error reading the location
402 * -EINVAL on a failed compare of the contents
403 * -EPERM on error writing to the location
404 * Any other value will be considered a failure.
406 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
408 /* May be defined in arch */
409 extern int ftrace_arch_read_dyn_info(char *buf, int size);
411 extern int skip_trace(unsigned long ip);
413 extern void ftrace_disable_daemon(void);
414 extern void ftrace_enable_daemon(void);
416 static inline int skip_trace(unsigned long ip) { return 0; }
417 static inline int ftrace_force_update(void) { return 0; }
418 static inline void ftrace_disable_daemon(void) { }
419 static inline void ftrace_enable_daemon(void) { }
420 static inline void ftrace_release_mod(struct module *mod) {}
421 static inline int register_ftrace_command(struct ftrace_func_command *cmd)
425 static inline int unregister_ftrace_command(char *cmd_name)
429 static inline int ftrace_text_reserved(void *start, void *end)
435 * Again users of functions that have ftrace_ops may not
436 * have them defined when ftrace is not enabled, but these
437 * functions may still be called. Use a macro instead of inline.
439 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
440 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
441 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
442 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
443 #define ftrace_free_filter(ops) do { } while (0)
445 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
446 size_t cnt, loff_t *ppos) { return -ENODEV; }
447 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
448 size_t cnt, loff_t *ppos) { return -ENODEV; }
449 static inline loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
454 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
455 #endif /* CONFIG_DYNAMIC_FTRACE */
457 /* totally disable ftrace - can not re-enable after this */
458 void ftrace_kill(void);
460 static inline void tracer_disable(void)
462 #ifdef CONFIG_FUNCTION_TRACER
468 * Ftrace disable/restore without lock. Some synchronization mechanism
469 * must be used to prevent ftrace_enabled to be changed between
472 static inline int __ftrace_enabled_save(void)
474 #ifdef CONFIG_FUNCTION_TRACER
475 int saved_ftrace_enabled = ftrace_enabled;
477 return saved_ftrace_enabled;
483 static inline void __ftrace_enabled_restore(int enabled)
485 #ifdef CONFIG_FUNCTION_TRACER
486 ftrace_enabled = enabled;
490 #ifndef HAVE_ARCH_CALLER_ADDR
491 # ifdef CONFIG_FRAME_POINTER
492 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
493 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
494 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
495 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
496 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
497 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
498 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
500 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
501 # define CALLER_ADDR1 0UL
502 # define CALLER_ADDR2 0UL
503 # define CALLER_ADDR3 0UL
504 # define CALLER_ADDR4 0UL
505 # define CALLER_ADDR5 0UL
506 # define CALLER_ADDR6 0UL
508 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */
510 #ifdef CONFIG_IRQSOFF_TRACER
511 extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
512 extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
514 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
515 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
518 #ifdef CONFIG_PREEMPT_TRACER
519 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
520 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
523 * Use defines instead of static inlines because some arches will make code out
524 * of the CALLER_ADDR, when we really want these to be a real nop.
526 # define trace_preempt_on(a0, a1) do { } while (0)
527 # define trace_preempt_off(a0, a1) do { } while (0)
530 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
531 extern void ftrace_init(void);
533 static inline void ftrace_init(void) { }
537 * Structure that defines an entry function trace.
539 struct ftrace_graph_ent {
540 unsigned long func; /* Current function */
545 * Structure that defines a return function trace.
547 struct ftrace_graph_ret {
548 unsigned long func; /* Current function */
549 unsigned long long calltime;
550 unsigned long long rettime;
551 /* Number of functions that overran the depth limit for current task */
552 unsigned long overrun;
556 /* Type of the callback handlers for tracing function graph*/
557 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
558 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
560 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
563 #define INIT_FTRACE_GRAPH .ret_stack = NULL,
566 * Stack of return addresses for functions
568 * Used in struct thread_info
570 struct ftrace_ret_stack {
573 unsigned long long calltime;
574 unsigned long long subtime;
579 * Primary handler of a function return.
580 * It relays on ftrace_return_to_handler.
581 * Defined in entry_32/64.S
583 extern void return_to_handler(void);
586 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
587 unsigned long frame_pointer);
590 * Sometimes we don't want to trace a function with the function
591 * graph tracer but we want them to keep traced by the usual function
592 * tracer if the function graph tracer is not configured.
594 #define __notrace_funcgraph notrace
597 * We want to which function is an entrypoint of a hardirq.
598 * That will help us to put a signal on output.
600 #define __irq_entry __attribute__((__section__(".irqentry.text")))
602 /* Limits of hardirq entrypoints */
603 extern char __irqentry_text_start[];
604 extern char __irqentry_text_end[];
606 #define FTRACE_RETFUNC_DEPTH 50
607 #define FTRACE_RETSTACK_ALLOC_SIZE 32
608 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
609 trace_func_graph_ent_t entryfunc);
611 extern void ftrace_graph_stop(void);
613 /* The current handlers in use */
614 extern trace_func_graph_ret_t ftrace_graph_return;
615 extern trace_func_graph_ent_t ftrace_graph_entry;
617 extern void unregister_ftrace_graph(void);
619 extern void ftrace_graph_init_task(struct task_struct *t);
620 extern void ftrace_graph_exit_task(struct task_struct *t);
621 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
623 static inline int task_curr_ret_stack(struct task_struct *t)
625 return t->curr_ret_stack;
628 static inline void pause_graph_tracing(void)
630 atomic_inc(¤t->tracing_graph_pause);
633 static inline void unpause_graph_tracing(void)
635 atomic_dec(¤t->tracing_graph_pause);
637 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
639 #define __notrace_funcgraph
641 #define INIT_FTRACE_GRAPH
643 static inline void ftrace_graph_init_task(struct task_struct *t) { }
644 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
645 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
647 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
648 trace_func_graph_ent_t entryfunc)
652 static inline void unregister_ftrace_graph(void) { }
654 static inline int task_curr_ret_stack(struct task_struct *tsk)
659 static inline void pause_graph_tracing(void) { }
660 static inline void unpause_graph_tracing(void) { }
661 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
663 #ifdef CONFIG_TRACING
665 /* flags for current->trace */
667 TSK_TRACE_FL_TRACE_BIT = 0,
668 TSK_TRACE_FL_GRAPH_BIT = 1,
671 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
672 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
675 static inline void set_tsk_trace_trace(struct task_struct *tsk)
677 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
680 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
682 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
685 static inline int test_tsk_trace_trace(struct task_struct *tsk)
687 return tsk->trace & TSK_TRACE_FL_TRACE;
690 static inline void set_tsk_trace_graph(struct task_struct *tsk)
692 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
695 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
697 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
700 static inline int test_tsk_trace_graph(struct task_struct *tsk)
702 return tsk->trace & TSK_TRACE_FL_GRAPH;
705 enum ftrace_dump_mode;
707 extern enum ftrace_dump_mode ftrace_dump_on_oops;
709 #ifdef CONFIG_PREEMPT
710 #define INIT_TRACE_RECURSION .trace_recursion = 0,
713 #endif /* CONFIG_TRACING */
715 #ifndef INIT_TRACE_RECURSION
716 #define INIT_TRACE_RECURSION
719 #ifdef CONFIG_FTRACE_SYSCALLS
721 unsigned long arch_syscall_addr(int nr);
723 #endif /* CONFIG_FTRACE_SYSCALLS */
725 #endif /* _LINUX_FTRACE_H */