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>
24 #ifdef CONFIG_FUNCTION_TRACER
26 extern int ftrace_enabled;
28 ftrace_enable_sysctl(struct ctl_table *table, int write,
29 void __user *buffer, size_t *lenp,
32 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
35 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
36 * set in the flags member.
38 * ENABLED - set/unset when ftrace_ops is registered/unregistered
39 * GLOBAL - set manualy by ftrace_ops user to denote the ftrace_ops
40 * is part of the global tracers sharing the same filter
41 * via set_ftrace_* debugfs files.
42 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
43 * allocated ftrace_ops which need special care
44 * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
45 * could be controled by following calls:
46 * ftrace_function_local_enable
47 * ftrace_function_local_disable
50 FTRACE_OPS_FL_ENABLED = 1 << 0,
51 FTRACE_OPS_FL_GLOBAL = 1 << 1,
52 FTRACE_OPS_FL_DYNAMIC = 1 << 2,
53 FTRACE_OPS_FL_CONTROL = 1 << 3,
58 struct ftrace_ops *next;
60 int __percpu *disabled;
61 #ifdef CONFIG_DYNAMIC_FTRACE
62 struct ftrace_hash *notrace_hash;
63 struct ftrace_hash *filter_hash;
67 extern int function_trace_stop;
70 * Type of the current tracing.
72 enum ftrace_tracing_type_t {
73 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
74 FTRACE_TYPE_RETURN, /* Hook the return of the function */
77 /* Current tracing type, default is FTRACE_TYPE_ENTER */
78 extern enum ftrace_tracing_type_t ftrace_tracing_type;
81 * ftrace_stop - stop function tracer.
83 * A quick way to stop the function tracer. Note this an on off switch,
84 * it is not something that is recursive like preempt_disable.
85 * This does not disable the calling of mcount, it only stops the
86 * calling of functions from mcount.
88 static inline void ftrace_stop(void)
90 function_trace_stop = 1;
94 * ftrace_start - start the function tracer.
96 * This function is the inverse of ftrace_stop. This does not enable
97 * the function tracing if the function tracer is disabled. This only
98 * sets the function tracer flag to continue calling the functions
101 static inline void ftrace_start(void)
103 function_trace_stop = 0;
107 * The ftrace_ops must be a static and should also
108 * be read_mostly. These functions do modify read_mostly variables
109 * so use them sparely. Never free an ftrace_op or modify the
110 * next pointer after it has been registered. Even after unregistering
111 * it, the next pointer may still be used internally.
113 int register_ftrace_function(struct ftrace_ops *ops);
114 int unregister_ftrace_function(struct ftrace_ops *ops);
115 void clear_ftrace_function(void);
118 * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
120 * This function enables tracing on current cpu by decreasing
121 * the per cpu control variable.
122 * It must be called with preemption disabled and only on ftrace_ops
123 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
124 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
126 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
128 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
131 (*this_cpu_ptr(ops->disabled))--;
135 * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
137 * This function enables tracing on current cpu by decreasing
138 * the per cpu control variable.
139 * It must be called with preemption disabled and only on ftrace_ops
140 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
141 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
143 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
145 if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
148 (*this_cpu_ptr(ops->disabled))++;
152 * ftrace_function_local_disabled - returns ftrace_ops disabled value
155 * This function returns value of ftrace_ops::disabled on current cpu.
156 * It must be called with preemption disabled and only on ftrace_ops
157 * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
158 * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
160 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
162 WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
163 return *this_cpu_ptr(ops->disabled);
166 extern void ftrace_stub(unsigned long a0, unsigned long a1);
168 #else /* !CONFIG_FUNCTION_TRACER */
170 * (un)register_ftrace_function must be a macro since the ops parameter
171 * must not be evaluated.
173 #define register_ftrace_function(ops) ({ 0; })
174 #define unregister_ftrace_function(ops) ({ 0; })
175 static inline void clear_ftrace_function(void) { }
176 static inline void ftrace_kill(void) { }
177 static inline void ftrace_stop(void) { }
178 static inline void ftrace_start(void) { }
179 #endif /* CONFIG_FUNCTION_TRACER */
181 #ifdef CONFIG_STACK_TRACER
182 extern int stack_tracer_enabled;
184 stack_trace_sysctl(struct ctl_table *table, int write,
185 void __user *buffer, size_t *lenp,
189 struct ftrace_func_command {
190 struct list_head list;
192 int (*func)(struct ftrace_hash *hash,
193 char *func, char *cmd,
194 char *params, int enable);
197 #ifdef CONFIG_DYNAMIC_FTRACE
199 int ftrace_arch_code_modify_prepare(void);
200 int ftrace_arch_code_modify_post_process(void);
202 void ftrace_bug(int err, unsigned long ip);
206 struct ftrace_probe_ops {
207 void (*func)(unsigned long ip,
208 unsigned long parent_ip,
210 int (*callback)(unsigned long ip, void **data);
211 void (*free)(void **data);
212 int (*print)(struct seq_file *m,
214 struct ftrace_probe_ops *ops,
219 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
222 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
225 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
226 extern void unregister_ftrace_function_probe_all(char *glob);
228 extern int ftrace_text_reserved(void *start, void *end);
231 FTRACE_FL_ENABLED = (1 << 30),
234 #define FTRACE_FL_MASK (0x3UL << 30)
235 #define FTRACE_REF_MAX ((1 << 30) - 1)
239 unsigned long ip; /* address of mcount call-site */
240 struct dyn_ftrace *freelist;
243 struct dyn_arch_ftrace arch;
246 int ftrace_force_update(void);
247 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
249 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
251 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
252 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
254 int register_ftrace_command(struct ftrace_func_command *cmd);
255 int unregister_ftrace_command(struct ftrace_func_command *cmd);
258 FTRACE_UPDATE_CALLS = (1 << 0),
259 FTRACE_DISABLE_CALLS = (1 << 1),
260 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
261 FTRACE_START_FUNC_RET = (1 << 3),
262 FTRACE_STOP_FUNC_RET = (1 << 4),
266 FTRACE_UPDATE_IGNORE,
267 FTRACE_UPDATE_MAKE_CALL,
268 FTRACE_UPDATE_MAKE_NOP,
272 FTRACE_ITER_FILTER = (1 << 0),
273 FTRACE_ITER_NOTRACE = (1 << 1),
274 FTRACE_ITER_PRINTALL = (1 << 2),
275 FTRACE_ITER_DO_HASH = (1 << 3),
276 FTRACE_ITER_HASH = (1 << 4),
277 FTRACE_ITER_ENABLED = (1 << 5),
280 void arch_ftrace_update_code(int command);
282 struct ftrace_rec_iter;
284 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
285 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
286 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
288 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
289 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
290 void ftrace_run_stop_machine(int command);
291 int ftrace_location(unsigned long ip);
293 extern ftrace_func_t ftrace_trace_function;
295 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
296 struct inode *inode, struct file *file);
297 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
298 size_t cnt, loff_t *ppos);
299 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
300 size_t cnt, loff_t *ppos);
301 loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin);
302 int ftrace_regex_release(struct inode *inode, struct file *file);
305 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
307 /* defined in arch */
308 extern int ftrace_ip_converted(unsigned long ip);
309 extern int ftrace_dyn_arch_init(void *data);
310 extern int ftrace_update_ftrace_func(ftrace_func_t func);
311 extern void ftrace_caller(void);
312 extern void ftrace_call(void);
313 extern void mcount_call(void);
316 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
318 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
319 extern void ftrace_graph_caller(void);
320 extern int ftrace_enable_ftrace_graph_caller(void);
321 extern int ftrace_disable_ftrace_graph_caller(void);
323 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
324 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
328 * ftrace_make_nop - convert code into nop
329 * @mod: module structure if called by module load initialization
330 * @rec: the mcount call site record
331 * @addr: the address that the call site should be calling
333 * This is a very sensitive operation and great care needs
334 * to be taken by the arch. The operation should carefully
335 * read the location, check to see if what is read is indeed
336 * what we expect it to be, and then on success of the compare,
337 * it should write to the location.
339 * The code segment at @rec->ip should be a caller to @addr
343 * -EFAULT on error reading the location
344 * -EINVAL on a failed compare of the contents
345 * -EPERM on error writing to the location
346 * Any other value will be considered a failure.
348 extern int ftrace_make_nop(struct module *mod,
349 struct dyn_ftrace *rec, unsigned long addr);
352 * ftrace_make_call - convert a nop call site into a call to addr
353 * @rec: the mcount call site record
354 * @addr: the address that the call site should call
356 * This is a very sensitive operation and great care needs
357 * to be taken by the arch. The operation should carefully
358 * read the location, check to see if what is read is indeed
359 * what we expect it to be, and then on success of the compare,
360 * it should write to the location.
362 * The code segment at @rec->ip should be a nop
366 * -EFAULT on error reading the location
367 * -EINVAL on a failed compare of the contents
368 * -EPERM on error writing to the location
369 * Any other value will be considered a failure.
371 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
373 /* May be defined in arch */
374 extern int ftrace_arch_read_dyn_info(char *buf, int size);
376 extern int skip_trace(unsigned long ip);
378 extern void ftrace_disable_daemon(void);
379 extern void ftrace_enable_daemon(void);
381 static inline int skip_trace(unsigned long ip) { return 0; }
382 static inline int ftrace_force_update(void) { return 0; }
383 static inline void ftrace_set_filter(unsigned char *buf, int len, int reset)
386 static inline void ftrace_disable_daemon(void) { }
387 static inline void ftrace_enable_daemon(void) { }
388 static inline void ftrace_release_mod(struct module *mod) {}
389 static inline int register_ftrace_command(struct ftrace_func_command *cmd)
393 static inline int unregister_ftrace_command(char *cmd_name)
397 static inline int ftrace_text_reserved(void *start, void *end)
403 * Again users of functions that have ftrace_ops may not
404 * have them defined when ftrace is not enabled, but these
405 * functions may still be called. Use a macro instead of inline.
407 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
408 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
410 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
411 size_t cnt, loff_t *ppos) { return -ENODEV; }
412 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
413 size_t cnt, loff_t *ppos) { return -ENODEV; }
414 static inline loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
419 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
420 #endif /* CONFIG_DYNAMIC_FTRACE */
422 /* totally disable ftrace - can not re-enable after this */
423 void ftrace_kill(void);
425 static inline void tracer_disable(void)
427 #ifdef CONFIG_FUNCTION_TRACER
433 * Ftrace disable/restore without lock. Some synchronization mechanism
434 * must be used to prevent ftrace_enabled to be changed between
437 static inline int __ftrace_enabled_save(void)
439 #ifdef CONFIG_FUNCTION_TRACER
440 int saved_ftrace_enabled = ftrace_enabled;
442 return saved_ftrace_enabled;
448 static inline void __ftrace_enabled_restore(int enabled)
450 #ifdef CONFIG_FUNCTION_TRACER
451 ftrace_enabled = enabled;
455 #ifndef HAVE_ARCH_CALLER_ADDR
456 # ifdef CONFIG_FRAME_POINTER
457 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
458 # define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
459 # define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
460 # define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
461 # define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
462 # define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
463 # define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
465 # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
466 # define CALLER_ADDR1 0UL
467 # define CALLER_ADDR2 0UL
468 # define CALLER_ADDR3 0UL
469 # define CALLER_ADDR4 0UL
470 # define CALLER_ADDR5 0UL
471 # define CALLER_ADDR6 0UL
473 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */
475 #ifdef CONFIG_IRQSOFF_TRACER
476 extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
477 extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
479 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
480 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
483 #ifdef CONFIG_PREEMPT_TRACER
484 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
485 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
487 static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { }
488 static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { }
491 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
492 extern void ftrace_init(void);
494 static inline void ftrace_init(void) { }
498 * Structure that defines an entry function trace.
500 struct ftrace_graph_ent {
501 unsigned long func; /* Current function */
506 * Structure that defines a return function trace.
508 struct ftrace_graph_ret {
509 unsigned long func; /* Current function */
510 unsigned long long calltime;
511 unsigned long long rettime;
512 /* Number of functions that overran the depth limit for current task */
513 unsigned long overrun;
517 /* Type of the callback handlers for tracing function graph*/
518 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
519 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
521 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
524 #define INIT_FTRACE_GRAPH .ret_stack = NULL,
527 * Stack of return addresses for functions
529 * Used in struct thread_info
531 struct ftrace_ret_stack {
534 unsigned long long calltime;
535 unsigned long long subtime;
540 * Primary handler of a function return.
541 * It relays on ftrace_return_to_handler.
542 * Defined in entry_32/64.S
544 extern void return_to_handler(void);
547 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
548 unsigned long frame_pointer);
551 * Sometimes we don't want to trace a function with the function
552 * graph tracer but we want them to keep traced by the usual function
553 * tracer if the function graph tracer is not configured.
555 #define __notrace_funcgraph notrace
558 * We want to which function is an entrypoint of a hardirq.
559 * That will help us to put a signal on output.
561 #define __irq_entry __attribute__((__section__(".irqentry.text")))
563 /* Limits of hardirq entrypoints */
564 extern char __irqentry_text_start[];
565 extern char __irqentry_text_end[];
567 #define FTRACE_RETFUNC_DEPTH 50
568 #define FTRACE_RETSTACK_ALLOC_SIZE 32
569 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
570 trace_func_graph_ent_t entryfunc);
572 extern void ftrace_graph_stop(void);
574 /* The current handlers in use */
575 extern trace_func_graph_ret_t ftrace_graph_return;
576 extern trace_func_graph_ent_t ftrace_graph_entry;
578 extern void unregister_ftrace_graph(void);
580 extern void ftrace_graph_init_task(struct task_struct *t);
581 extern void ftrace_graph_exit_task(struct task_struct *t);
582 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
584 static inline int task_curr_ret_stack(struct task_struct *t)
586 return t->curr_ret_stack;
589 static inline void pause_graph_tracing(void)
591 atomic_inc(¤t->tracing_graph_pause);
594 static inline void unpause_graph_tracing(void)
596 atomic_dec(¤t->tracing_graph_pause);
598 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
600 #define __notrace_funcgraph
602 #define INIT_FTRACE_GRAPH
604 static inline void ftrace_graph_init_task(struct task_struct *t) { }
605 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
606 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
608 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
609 trace_func_graph_ent_t entryfunc)
613 static inline void unregister_ftrace_graph(void) { }
615 static inline int task_curr_ret_stack(struct task_struct *tsk)
620 static inline void pause_graph_tracing(void) { }
621 static inline void unpause_graph_tracing(void) { }
622 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
624 #ifdef CONFIG_TRACING
626 /* flags for current->trace */
628 TSK_TRACE_FL_TRACE_BIT = 0,
629 TSK_TRACE_FL_GRAPH_BIT = 1,
632 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
633 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
636 static inline void set_tsk_trace_trace(struct task_struct *tsk)
638 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
641 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
643 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
646 static inline int test_tsk_trace_trace(struct task_struct *tsk)
648 return tsk->trace & TSK_TRACE_FL_TRACE;
651 static inline void set_tsk_trace_graph(struct task_struct *tsk)
653 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
656 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
658 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
661 static inline int test_tsk_trace_graph(struct task_struct *tsk)
663 return tsk->trace & TSK_TRACE_FL_GRAPH;
666 enum ftrace_dump_mode;
668 extern enum ftrace_dump_mode ftrace_dump_on_oops;
670 #ifdef CONFIG_PREEMPT
671 #define INIT_TRACE_RECURSION .trace_recursion = 0,
674 #endif /* CONFIG_TRACING */
676 #ifndef INIT_TRACE_RECURSION
677 #define INIT_TRACE_RECURSION
680 #ifdef CONFIG_FTRACE_SYSCALLS
682 unsigned long arch_syscall_addr(int nr);
684 #endif /* CONFIG_FTRACE_SYSCALLS */
686 #endif /* _LINUX_FTRACE_H */