1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Ftrace header. For implementation details beyond the random comments
4 * scattered below, see: Documentation/trace/ftrace-design.rst
7 #ifndef _LINUX_FTRACE_H
8 #define _LINUX_FTRACE_H
10 #include <linux/trace_clock.h>
11 #include <linux/kallsyms.h>
12 #include <linux/linkage.h>
13 #include <linux/bitops.h>
14 #include <linux/ptrace.h>
15 #include <linux/ktime.h>
16 #include <linux/sched.h>
17 #include <linux/types.h>
18 #include <linux/init.h>
21 #include <asm/ftrace.h>
24 * If the arch supports passing the variable contents of
25 * function_trace_op as the third parameter back from the
26 * mcount call, then the arch should define this as 1.
28 #ifndef ARCH_SUPPORTS_FTRACE_OPS
29 #define ARCH_SUPPORTS_FTRACE_OPS 0
33 * If the arch's mcount caller does not support all of ftrace's
34 * features, then it must call an indirect function that
35 * does. Or at least does enough to prevent any unwelcomed side effects.
37 #if !ARCH_SUPPORTS_FTRACE_OPS
38 # define FTRACE_FORCE_LIST_FUNC 1
40 # define FTRACE_FORCE_LIST_FUNC 0
43 /* Main tracing buffer and events set up */
45 void trace_init(void);
46 void early_trace_init(void);
48 static inline void trace_init(void) { }
49 static inline void early_trace_init(void) { }
55 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
56 defined(CONFIG_DYNAMIC_FTRACE)
58 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
59 unsigned long *off, char **modname, char *sym);
60 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
61 char *type, char *name,
62 char *module_name, int *exported);
64 static inline const char *
65 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
66 unsigned long *off, char **modname, char *sym)
70 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
71 char *type, char *name,
72 char *module_name, int *exported)
79 #ifdef CONFIG_FUNCTION_TRACER
81 extern int ftrace_enabled;
83 ftrace_enable_sysctl(struct ctl_table *table, int write,
84 void __user *buffer, size_t *lenp,
89 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
90 struct ftrace_ops *op, struct pt_regs *regs);
92 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
95 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
96 * set in the flags member.
97 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and
98 * IPMODIFY are a kind of attribute flags which can be set only before
99 * registering the ftrace_ops, and can not be modified while registered.
100 * Changing those attribute flags after registering ftrace_ops will
101 * cause unexpected results.
103 * ENABLED - set/unset when ftrace_ops is registered/unregistered
104 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
105 * allocated ftrace_ops which need special care
106 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
107 * and passed to the callback. If this flag is set, but the
108 * architecture does not support passing regs
109 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
110 * ftrace_ops will fail to register, unless the next flag
112 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
113 * handler can handle an arch that does not save regs
114 * (the handler tests if regs == NULL), then it can set
115 * this flag instead. It will not fail registering the ftrace_ops
116 * but, the regs field will be NULL if the arch does not support
117 * passing regs to the handler.
118 * Note, if this flag is set, the SAVE_REGS flag will automatically
119 * get set upon registering the ftrace_ops, if the arch supports it.
120 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
121 * that the call back has its own recursion protection. If it does
122 * not set this, then the ftrace infrastructure will add recursion
123 * protection for the caller.
124 * STUB - The ftrace_ops is just a place holder.
125 * INITIALIZED - The ftrace_ops has already been initialized (first use time
126 * register_ftrace_function() is called, it will initialized the ops)
127 * DELETED - The ops are being deleted, do not let them be registered again.
128 * ADDING - The ops is in the process of being added.
129 * REMOVING - The ops is in the process of being removed.
130 * MODIFYING - The ops is in the process of changing its filter functions.
131 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
132 * The arch specific code sets this flag when it allocated a
133 * trampoline. This lets the arch know that it can update the
134 * trampoline in case the callback function changes.
135 * The ftrace_ops trampoline can be set by the ftrace users, and
136 * in such cases the arch must not modify it. Only the arch ftrace
137 * core code should set this flag.
138 * IPMODIFY - The ops can modify the IP register. This can only be set with
139 * SAVE_REGS. If another ops with this flag set is already registered
140 * for any of the functions that this ops will be registered for, then
141 * this ops will fail to register or set_filter_ip.
142 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
143 * RCU - Set when the ops can only be called when RCU is watching.
144 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
147 FTRACE_OPS_FL_ENABLED = 1 << 0,
148 FTRACE_OPS_FL_DYNAMIC = 1 << 1,
149 FTRACE_OPS_FL_SAVE_REGS = 1 << 2,
150 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 3,
151 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 4,
152 FTRACE_OPS_FL_STUB = 1 << 5,
153 FTRACE_OPS_FL_INITIALIZED = 1 << 6,
154 FTRACE_OPS_FL_DELETED = 1 << 7,
155 FTRACE_OPS_FL_ADDING = 1 << 8,
156 FTRACE_OPS_FL_REMOVING = 1 << 9,
157 FTRACE_OPS_FL_MODIFYING = 1 << 10,
158 FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 11,
159 FTRACE_OPS_FL_IPMODIFY = 1 << 12,
160 FTRACE_OPS_FL_PID = 1 << 13,
161 FTRACE_OPS_FL_RCU = 1 << 14,
162 FTRACE_OPS_FL_TRACE_ARRAY = 1 << 15,
165 #ifdef CONFIG_DYNAMIC_FTRACE
166 /* The hash used to know what functions callbacks trace */
167 struct ftrace_ops_hash {
168 struct ftrace_hash __rcu *notrace_hash;
169 struct ftrace_hash __rcu *filter_hash;
170 struct mutex regex_lock;
173 void ftrace_free_init_mem(void);
174 void ftrace_free_mem(struct module *mod, void *start, void *end);
176 static inline void ftrace_free_init_mem(void) { }
177 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
181 * Note, ftrace_ops can be referenced outside of RCU protection, unless
182 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
183 * core data, the unregistering of it will perform a scheduling on all CPUs
184 * to make sure that there are no more users. Depending on the load of the
185 * system that may take a bit of time.
187 * Any private data added must also take care not to be freed and if private
188 * data is added to a ftrace_ops that is in core code, the user of the
189 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
193 struct ftrace_ops __rcu *next;
196 ftrace_func_t saved_func;
197 #ifdef CONFIG_DYNAMIC_FTRACE
198 struct ftrace_ops_hash local_hash;
199 struct ftrace_ops_hash *func_hash;
200 struct ftrace_ops_hash old_hash;
201 unsigned long trampoline;
202 unsigned long trampoline_size;
207 * Type of the current tracing.
209 enum ftrace_tracing_type_t {
210 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
211 FTRACE_TYPE_RETURN, /* Hook the return of the function */
214 /* Current tracing type, default is FTRACE_TYPE_ENTER */
215 extern enum ftrace_tracing_type_t ftrace_tracing_type;
218 * The ftrace_ops must be a static and should also
219 * be read_mostly. These functions do modify read_mostly variables
220 * so use them sparely. Never free an ftrace_op or modify the
221 * next pointer after it has been registered. Even after unregistering
222 * it, the next pointer may still be used internally.
224 int register_ftrace_function(struct ftrace_ops *ops);
225 int unregister_ftrace_function(struct ftrace_ops *ops);
227 extern void ftrace_stub(unsigned long a0, unsigned long a1,
228 struct ftrace_ops *op, struct pt_regs *regs);
230 #else /* !CONFIG_FUNCTION_TRACER */
232 * (un)register_ftrace_function must be a macro since the ops parameter
233 * must not be evaluated.
235 #define register_ftrace_function(ops) ({ 0; })
236 #define unregister_ftrace_function(ops) ({ 0; })
237 static inline void ftrace_kill(void) { }
238 static inline void ftrace_free_init_mem(void) { }
239 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
240 #endif /* CONFIG_FUNCTION_TRACER */
242 #ifdef CONFIG_STACK_TRACER
244 extern int stack_tracer_enabled;
246 int stack_trace_sysctl(struct ctl_table *table, int write,
247 void __user *buffer, size_t *lenp,
250 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
251 DECLARE_PER_CPU(int, disable_stack_tracer);
254 * stack_tracer_disable - temporarily disable the stack tracer
256 * There's a few locations (namely in RCU) where stack tracing
257 * cannot be executed. This function is used to disable stack
258 * tracing during those critical sections.
260 * This function must be called with preemption or interrupts
261 * disabled and stack_tracer_enable() must be called shortly after
262 * while preemption or interrupts are still disabled.
264 static inline void stack_tracer_disable(void)
266 /* Preemption or interupts must be disabled */
267 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
268 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
269 this_cpu_inc(disable_stack_tracer);
273 * stack_tracer_enable - re-enable the stack tracer
275 * After stack_tracer_disable() is called, stack_tracer_enable()
276 * must be called shortly afterward.
278 static inline void stack_tracer_enable(void)
280 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
281 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
282 this_cpu_dec(disable_stack_tracer);
285 static inline void stack_tracer_disable(void) { }
286 static inline void stack_tracer_enable(void) { }
289 #ifdef CONFIG_DYNAMIC_FTRACE
291 int ftrace_arch_code_modify_prepare(void);
292 int ftrace_arch_code_modify_post_process(void);
296 enum ftrace_bug_type {
303 extern enum ftrace_bug_type ftrace_bug_type;
306 * Archs can set this to point to a variable that holds the value that was
307 * expected at the call site before calling ftrace_bug().
309 extern const void *ftrace_expected;
311 void ftrace_bug(int err, struct dyn_ftrace *rec);
315 extern int ftrace_text_reserved(const void *start, const void *end);
317 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
319 bool is_ftrace_trampoline(unsigned long addr);
322 * The dyn_ftrace record's flags field is split into two parts.
323 * the first part which is '0-FTRACE_REF_MAX' is a counter of
324 * the number of callbacks that have registered the function that
325 * the dyn_ftrace descriptor represents.
327 * The second part is a mask:
328 * ENABLED - the function is being traced
329 * REGS - the record wants the function to save regs
330 * REGS_EN - the function is set up to save regs.
331 * IPMODIFY - the record allows for the IP address to be changed.
332 * DISABLED - the record is not ready to be touched yet
334 * When a new ftrace_ops is registered and wants a function to save
335 * pt_regs, the rec->flag REGS is set. When the function has been
336 * set up to save regs, the REG_EN flag is set. Once a function
337 * starts saving regs it will do so until all ftrace_ops are removed
338 * from tracing that function.
341 FTRACE_FL_ENABLED = (1UL << 31),
342 FTRACE_FL_REGS = (1UL << 30),
343 FTRACE_FL_REGS_EN = (1UL << 29),
344 FTRACE_FL_TRAMP = (1UL << 28),
345 FTRACE_FL_TRAMP_EN = (1UL << 27),
346 FTRACE_FL_IPMODIFY = (1UL << 26),
347 FTRACE_FL_DISABLED = (1UL << 25),
350 #define FTRACE_REF_MAX_SHIFT 25
351 #define FTRACE_FL_BITS 7
352 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1)
353 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
354 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
356 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK)
359 unsigned long ip; /* address of mcount call-site */
361 struct dyn_arch_ftrace arch;
364 int ftrace_force_update(void);
365 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
366 int remove, int reset);
367 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
369 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
371 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
372 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
373 void ftrace_free_filter(struct ftrace_ops *ops);
374 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
377 FTRACE_UPDATE_CALLS = (1 << 0),
378 FTRACE_DISABLE_CALLS = (1 << 1),
379 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
380 FTRACE_START_FUNC_RET = (1 << 3),
381 FTRACE_STOP_FUNC_RET = (1 << 4),
382 FTRACE_MAY_SLEEP = (1 << 5),
386 * The FTRACE_UPDATE_* enum is used to pass information back
387 * from the ftrace_update_record() and ftrace_test_record()
388 * functions. These are called by the code update routines
389 * to find out what is to be done for a given function.
391 * IGNORE - The function is already what we want it to be
392 * MAKE_CALL - Start tracing the function
393 * MODIFY_CALL - Stop saving regs for the function
394 * MAKE_NOP - Stop tracing the function
397 FTRACE_UPDATE_IGNORE,
398 FTRACE_UPDATE_MAKE_CALL,
399 FTRACE_UPDATE_MODIFY_CALL,
400 FTRACE_UPDATE_MAKE_NOP,
404 FTRACE_ITER_FILTER = (1 << 0),
405 FTRACE_ITER_NOTRACE = (1 << 1),
406 FTRACE_ITER_PRINTALL = (1 << 2),
407 FTRACE_ITER_DO_PROBES = (1 << 3),
408 FTRACE_ITER_PROBE = (1 << 4),
409 FTRACE_ITER_MOD = (1 << 5),
410 FTRACE_ITER_ENABLED = (1 << 6),
413 void arch_ftrace_update_code(int command);
414 void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
415 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
416 void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
418 struct ftrace_rec_iter;
420 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
421 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
422 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
424 #define for_ftrace_rec_iter(iter) \
425 for (iter = ftrace_rec_iter_start(); \
427 iter = ftrace_rec_iter_next(iter))
430 int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
431 int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
432 void ftrace_run_stop_machine(int command);
433 unsigned long ftrace_location(unsigned long ip);
434 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
435 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
436 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
438 extern ftrace_func_t ftrace_trace_function;
440 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
441 struct inode *inode, struct file *file);
442 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
443 size_t cnt, loff_t *ppos);
444 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
445 size_t cnt, loff_t *ppos);
446 int ftrace_regex_release(struct inode *inode, struct file *file);
449 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
451 /* defined in arch */
452 extern int ftrace_ip_converted(unsigned long ip);
453 extern int ftrace_dyn_arch_init(void);
454 extern void ftrace_replace_code(int enable);
455 extern int ftrace_update_ftrace_func(ftrace_func_t func);
456 extern void ftrace_caller(void);
457 extern void ftrace_regs_caller(void);
458 extern void ftrace_call(void);
459 extern void ftrace_regs_call(void);
460 extern void mcount_call(void);
462 void ftrace_modify_all_code(int command);
465 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
468 #ifndef FTRACE_GRAPH_ADDR
469 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
472 #ifndef FTRACE_REGS_ADDR
473 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
474 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
476 # define FTRACE_REGS_ADDR FTRACE_ADDR
481 * If an arch would like functions that are only traced
482 * by the function graph tracer to jump directly to its own
483 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
484 * to be that address to jump to.
486 #ifndef FTRACE_GRAPH_TRAMP_ADDR
487 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
490 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
491 extern void ftrace_graph_caller(void);
492 extern int ftrace_enable_ftrace_graph_caller(void);
493 extern int ftrace_disable_ftrace_graph_caller(void);
495 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
496 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
500 * ftrace_make_nop - convert code into nop
501 * @mod: module structure if called by module load initialization
502 * @rec: the call site record (e.g. mcount/fentry)
503 * @addr: the address that the call site should be calling
505 * This is a very sensitive operation and great care needs
506 * to be taken by the arch. The operation should carefully
507 * read the location, check to see if what is read is indeed
508 * what we expect it to be, and then on success of the compare,
509 * it should write to the location.
511 * The code segment at @rec->ip should be a caller to @addr
515 * -EFAULT on error reading the location
516 * -EINVAL on a failed compare of the contents
517 * -EPERM on error writing to the location
518 * Any other value will be considered a failure.
520 extern int ftrace_make_nop(struct module *mod,
521 struct dyn_ftrace *rec, unsigned long addr);
525 * ftrace_init_nop - initialize a nop call site
526 * @mod: module structure if called by module load initialization
527 * @rec: the call site record (e.g. mcount/fentry)
529 * This is a very sensitive operation and great care needs
530 * to be taken by the arch. The operation should carefully
531 * read the location, check to see if what is read is indeed
532 * what we expect it to be, and then on success of the compare,
533 * it should write to the location.
535 * The code segment at @rec->ip should contain the contents created by
540 * -EFAULT on error reading the location
541 * -EINVAL on a failed compare of the contents
542 * -EPERM on error writing to the location
543 * Any other value will be considered a failure.
545 #ifndef ftrace_init_nop
546 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
548 return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
553 * ftrace_make_call - convert a nop call site into a call to addr
554 * @rec: the call site record (e.g. mcount/fentry)
555 * @addr: the address that the call site should call
557 * This is a very sensitive operation and great care needs
558 * to be taken by the arch. The operation should carefully
559 * read the location, check to see if what is read is indeed
560 * what we expect it to be, and then on success of the compare,
561 * it should write to the location.
563 * The code segment at @rec->ip should be a nop
567 * -EFAULT on error reading the location
568 * -EINVAL on a failed compare of the contents
569 * -EPERM on error writing to the location
570 * Any other value will be considered a failure.
572 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
574 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
576 * ftrace_modify_call - convert from one addr to another (no nop)
577 * @rec: the call site record (e.g. mcount/fentry)
578 * @old_addr: the address expected to be currently called to
579 * @addr: the address to change to
581 * This is a very sensitive operation and great care needs
582 * to be taken by the arch. The operation should carefully
583 * read the location, check to see if what is read is indeed
584 * what we expect it to be, and then on success of the compare,
585 * it should write to the location.
587 * The code segment at @rec->ip should be a caller to @old_addr
591 * -EFAULT on error reading the location
592 * -EINVAL on a failed compare of the contents
593 * -EPERM on error writing to the location
594 * Any other value will be considered a failure.
596 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
599 /* Should never be called */
600 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
607 /* May be defined in arch */
608 extern int ftrace_arch_read_dyn_info(char *buf, int size);
610 extern int skip_trace(unsigned long ip);
611 extern void ftrace_module_init(struct module *mod);
612 extern void ftrace_module_enable(struct module *mod);
613 extern void ftrace_release_mod(struct module *mod);
615 extern void ftrace_disable_daemon(void);
616 extern void ftrace_enable_daemon(void);
617 #else /* CONFIG_DYNAMIC_FTRACE */
618 static inline int skip_trace(unsigned long ip) { return 0; }
619 static inline int ftrace_force_update(void) { return 0; }
620 static inline void ftrace_disable_daemon(void) { }
621 static inline void ftrace_enable_daemon(void) { }
622 static inline void ftrace_module_init(struct module *mod) { }
623 static inline void ftrace_module_enable(struct module *mod) { }
624 static inline void ftrace_release_mod(struct module *mod) { }
625 static inline int ftrace_text_reserved(const void *start, const void *end)
629 static inline unsigned long ftrace_location(unsigned long ip)
635 * Again users of functions that have ftrace_ops may not
636 * have them defined when ftrace is not enabled, but these
637 * functions may still be called. Use a macro instead of inline.
639 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
640 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
641 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
642 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
643 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
644 #define ftrace_free_filter(ops) do { } while (0)
645 #define ftrace_ops_set_global_filter(ops) do { } while (0)
647 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
648 size_t cnt, loff_t *ppos) { return -ENODEV; }
649 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
650 size_t cnt, loff_t *ppos) { return -ENODEV; }
652 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
654 static inline bool is_ftrace_trampoline(unsigned long addr)
658 #endif /* CONFIG_DYNAMIC_FTRACE */
660 /* totally disable ftrace - can not re-enable after this */
661 void ftrace_kill(void);
663 static inline void tracer_disable(void)
665 #ifdef CONFIG_FUNCTION_TRACER
671 * Ftrace disable/restore without lock. Some synchronization mechanism
672 * must be used to prevent ftrace_enabled to be changed between
675 static inline int __ftrace_enabled_save(void)
677 #ifdef CONFIG_FUNCTION_TRACER
678 int saved_ftrace_enabled = ftrace_enabled;
680 return saved_ftrace_enabled;
686 static inline void __ftrace_enabled_restore(int enabled)
688 #ifdef CONFIG_FUNCTION_TRACER
689 ftrace_enabled = enabled;
693 /* All archs should have this, but we define it for consistency */
694 #ifndef ftrace_return_address0
695 # define ftrace_return_address0 __builtin_return_address(0)
698 /* Archs may use other ways for ADDR1 and beyond */
699 #ifndef ftrace_return_address
700 # ifdef CONFIG_FRAME_POINTER
701 # define ftrace_return_address(n) __builtin_return_address(n)
703 # define ftrace_return_address(n) 0UL
707 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
708 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
709 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
710 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
711 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
712 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
713 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
715 static inline unsigned long get_lock_parent_ip(void)
717 unsigned long addr = CALLER_ADDR0;
719 if (!in_lock_functions(addr))
722 if (!in_lock_functions(addr))
727 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
728 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
729 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
732 * Use defines instead of static inlines because some arches will make code out
733 * of the CALLER_ADDR, when we really want these to be a real nop.
735 # define trace_preempt_on(a0, a1) do { } while (0)
736 # define trace_preempt_off(a0, a1) do { } while (0)
739 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
740 extern void ftrace_init(void);
741 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
742 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
744 #define FTRACE_CALLSITE_SECTION "__mcount_loc"
747 static inline void ftrace_init(void) { }
751 * Structure that defines an entry function trace.
752 * It's already packed but the attribute "packed" is needed
753 * to remove extra padding at the end.
755 struct ftrace_graph_ent {
756 unsigned long func; /* Current function */
761 * Structure that defines a return function trace.
762 * It's already packed but the attribute "packed" is needed
763 * to remove extra padding at the end.
765 struct ftrace_graph_ret {
766 unsigned long func; /* Current function */
767 /* Number of functions that overran the depth limit for current task */
768 unsigned long overrun;
769 unsigned long long calltime;
770 unsigned long long rettime;
774 /* Type of the callback handlers for tracing function graph*/
775 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
776 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
778 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
780 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
783 trace_func_graph_ent_t entryfunc;
784 trace_func_graph_ret_t retfunc;
788 * Stack of return addresses for functions
790 * Used in struct thread_info
792 struct ftrace_ret_stack {
795 unsigned long long calltime;
796 #ifdef CONFIG_FUNCTION_PROFILER
797 unsigned long long subtime;
799 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
802 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
808 * Primary handler of a function return.
809 * It relays on ftrace_return_to_handler.
810 * Defined in entry_32/64.S
812 extern void return_to_handler(void);
815 function_graph_enter(unsigned long ret, unsigned long func,
816 unsigned long frame_pointer, unsigned long *retp);
818 struct ftrace_ret_stack *
819 ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
821 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
822 unsigned long ret, unsigned long *retp);
825 * Sometimes we don't want to trace a function with the function
826 * graph tracer but we want them to keep traced by the usual function
827 * tracer if the function graph tracer is not configured.
829 #define __notrace_funcgraph notrace
831 #define FTRACE_RETFUNC_DEPTH 50
832 #define FTRACE_RETSTACK_ALLOC_SIZE 32
834 extern int register_ftrace_graph(struct fgraph_ops *ops);
835 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
837 extern bool ftrace_graph_is_dead(void);
838 extern void ftrace_graph_stop(void);
840 /* The current handlers in use */
841 extern trace_func_graph_ret_t ftrace_graph_return;
842 extern trace_func_graph_ent_t ftrace_graph_entry;
844 extern void ftrace_graph_init_task(struct task_struct *t);
845 extern void ftrace_graph_exit_task(struct task_struct *t);
846 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
848 static inline void pause_graph_tracing(void)
850 atomic_inc(¤t->tracing_graph_pause);
853 static inline void unpause_graph_tracing(void)
855 atomic_dec(¤t->tracing_graph_pause);
857 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
859 #define __notrace_funcgraph
861 static inline void ftrace_graph_init_task(struct task_struct *t) { }
862 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
863 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
865 /* Define as macros as fgraph_ops may not be defined */
866 #define register_ftrace_graph(ops) ({ -1; })
867 #define unregister_ftrace_graph(ops) do { } while (0)
869 static inline unsigned long
870 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
876 static inline void pause_graph_tracing(void) { }
877 static inline void unpause_graph_tracing(void) { }
878 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
880 #ifdef CONFIG_TRACING
882 /* flags for current->trace */
884 TSK_TRACE_FL_TRACE_BIT = 0,
885 TSK_TRACE_FL_GRAPH_BIT = 1,
888 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
889 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
892 static inline void set_tsk_trace_trace(struct task_struct *tsk)
894 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
897 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
899 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
902 static inline int test_tsk_trace_trace(struct task_struct *tsk)
904 return tsk->trace & TSK_TRACE_FL_TRACE;
907 static inline void set_tsk_trace_graph(struct task_struct *tsk)
909 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
912 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
914 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
917 static inline int test_tsk_trace_graph(struct task_struct *tsk)
919 return tsk->trace & TSK_TRACE_FL_GRAPH;
922 enum ftrace_dump_mode;
924 extern enum ftrace_dump_mode ftrace_dump_on_oops;
925 extern int tracepoint_printk;
927 extern void disable_trace_on_warning(void);
928 extern int __disable_trace_on_warning;
930 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
931 void __user *buffer, size_t *lenp,
934 #else /* CONFIG_TRACING */
935 static inline void disable_trace_on_warning(void) { }
936 #endif /* CONFIG_TRACING */
938 #ifdef CONFIG_FTRACE_SYSCALLS
940 unsigned long arch_syscall_addr(int nr);
942 #endif /* CONFIG_FTRACE_SYSCALLS */
944 #endif /* _LINUX_FTRACE_H */