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) { }
54 struct ftrace_direct_func;
56 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
57 defined(CONFIG_DYNAMIC_FTRACE)
59 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
60 unsigned long *off, char **modname, char *sym);
61 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
62 char *type, char *name,
63 char *module_name, int *exported);
65 static inline const char *
66 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
67 unsigned long *off, char **modname, char *sym)
71 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
72 char *type, char *name,
73 char *module_name, int *exported)
80 #ifdef CONFIG_FUNCTION_TRACER
82 extern int ftrace_enabled;
84 ftrace_enable_sysctl(struct ctl_table *table, int write,
85 void __user *buffer, size_t *lenp,
90 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
91 struct ftrace_ops *op, struct pt_regs *regs);
93 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
96 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
97 * set in the flags member.
98 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and
99 * IPMODIFY are a kind of attribute flags which can be set only before
100 * registering the ftrace_ops, and can not be modified while registered.
101 * Changing those attribute flags after registering ftrace_ops will
102 * cause unexpected results.
104 * ENABLED - set/unset when ftrace_ops is registered/unregistered
105 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
106 * allocated ftrace_ops which need special care
107 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
108 * and passed to the callback. If this flag is set, but the
109 * architecture does not support passing regs
110 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
111 * ftrace_ops will fail to register, unless the next flag
113 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
114 * handler can handle an arch that does not save regs
115 * (the handler tests if regs == NULL), then it can set
116 * this flag instead. It will not fail registering the ftrace_ops
117 * but, the regs field will be NULL if the arch does not support
118 * passing regs to the handler.
119 * Note, if this flag is set, the SAVE_REGS flag will automatically
120 * get set upon registering the ftrace_ops, if the arch supports it.
121 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
122 * that the call back has its own recursion protection. If it does
123 * not set this, then the ftrace infrastructure will add recursion
124 * protection for the caller.
125 * STUB - The ftrace_ops is just a place holder.
126 * INITIALIZED - The ftrace_ops has already been initialized (first use time
127 * register_ftrace_function() is called, it will initialized the ops)
128 * DELETED - The ops are being deleted, do not let them be registered again.
129 * ADDING - The ops is in the process of being added.
130 * REMOVING - The ops is in the process of being removed.
131 * MODIFYING - The ops is in the process of changing its filter functions.
132 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
133 * The arch specific code sets this flag when it allocated a
134 * trampoline. This lets the arch know that it can update the
135 * trampoline in case the callback function changes.
136 * The ftrace_ops trampoline can be set by the ftrace users, and
137 * in such cases the arch must not modify it. Only the arch ftrace
138 * core code should set this flag.
139 * IPMODIFY - The ops can modify the IP register. This can only be set with
140 * SAVE_REGS. If another ops with this flag set is already registered
141 * for any of the functions that this ops will be registered for, then
142 * this ops will fail to register or set_filter_ip.
143 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
144 * RCU - Set when the ops can only be called when RCU is watching.
145 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
146 * PERMANENT - Set when the ops is permanent and should not be affected by
148 * DIRECT - Used by the direct ftrace_ops helper for direct functions
149 * (internal ftrace only, should not be used by others)
152 FTRACE_OPS_FL_ENABLED = BIT(0),
153 FTRACE_OPS_FL_DYNAMIC = BIT(1),
154 FTRACE_OPS_FL_SAVE_REGS = BIT(2),
155 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3),
156 FTRACE_OPS_FL_RECURSION_SAFE = BIT(4),
157 FTRACE_OPS_FL_STUB = BIT(5),
158 FTRACE_OPS_FL_INITIALIZED = BIT(6),
159 FTRACE_OPS_FL_DELETED = BIT(7),
160 FTRACE_OPS_FL_ADDING = BIT(8),
161 FTRACE_OPS_FL_REMOVING = BIT(9),
162 FTRACE_OPS_FL_MODIFYING = BIT(10),
163 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11),
164 FTRACE_OPS_FL_IPMODIFY = BIT(12),
165 FTRACE_OPS_FL_PID = BIT(13),
166 FTRACE_OPS_FL_RCU = BIT(14),
167 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15),
168 FTRACE_OPS_FL_PERMANENT = BIT(16),
169 FTRACE_OPS_FL_DIRECT = BIT(17),
172 #ifdef CONFIG_DYNAMIC_FTRACE
173 /* The hash used to know what functions callbacks trace */
174 struct ftrace_ops_hash {
175 struct ftrace_hash __rcu *notrace_hash;
176 struct ftrace_hash __rcu *filter_hash;
177 struct mutex regex_lock;
180 void ftrace_free_init_mem(void);
181 void ftrace_free_mem(struct module *mod, void *start, void *end);
183 static inline void ftrace_free_init_mem(void) { }
184 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
188 * Note, ftrace_ops can be referenced outside of RCU protection, unless
189 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
190 * core data, the unregistering of it will perform a scheduling on all CPUs
191 * to make sure that there are no more users. Depending on the load of the
192 * system that may take a bit of time.
194 * Any private data added must also take care not to be freed and if private
195 * data is added to a ftrace_ops that is in core code, the user of the
196 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
200 struct ftrace_ops __rcu *next;
203 ftrace_func_t saved_func;
204 #ifdef CONFIG_DYNAMIC_FTRACE
205 struct ftrace_ops_hash local_hash;
206 struct ftrace_ops_hash *func_hash;
207 struct ftrace_ops_hash old_hash;
208 unsigned long trampoline;
209 unsigned long trampoline_size;
214 * Type of the current tracing.
216 enum ftrace_tracing_type_t {
217 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
218 FTRACE_TYPE_RETURN, /* Hook the return of the function */
221 /* Current tracing type, default is FTRACE_TYPE_ENTER */
222 extern enum ftrace_tracing_type_t ftrace_tracing_type;
225 * The ftrace_ops must be a static and should also
226 * be read_mostly. These functions do modify read_mostly variables
227 * so use them sparely. Never free an ftrace_op or modify the
228 * next pointer after it has been registered. Even after unregistering
229 * it, the next pointer may still be used internally.
231 int register_ftrace_function(struct ftrace_ops *ops);
232 int unregister_ftrace_function(struct ftrace_ops *ops);
234 extern void ftrace_stub(unsigned long a0, unsigned long a1,
235 struct ftrace_ops *op, struct pt_regs *regs);
237 #else /* !CONFIG_FUNCTION_TRACER */
239 * (un)register_ftrace_function must be a macro since the ops parameter
240 * must not be evaluated.
242 #define register_ftrace_function(ops) ({ 0; })
243 #define unregister_ftrace_function(ops) ({ 0; })
244 static inline void ftrace_kill(void) { }
245 static inline void ftrace_free_init_mem(void) { }
246 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
247 #endif /* CONFIG_FUNCTION_TRACER */
249 struct ftrace_func_entry {
250 struct hlist_node hlist;
252 unsigned long direct; /* for direct lookup only */
257 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
258 extern int ftrace_direct_func_count;
259 int register_ftrace_direct(unsigned long ip, unsigned long addr);
260 int unregister_ftrace_direct(unsigned long ip, unsigned long addr);
261 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr);
262 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr);
263 int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
264 struct dyn_ftrace *rec,
265 unsigned long old_addr,
266 unsigned long new_addr);
268 # define ftrace_direct_func_count 0
269 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
273 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
277 static inline int modify_ftrace_direct(unsigned long ip,
278 unsigned long old_addr, unsigned long new_addr)
282 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
286 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
287 struct dyn_ftrace *rec,
288 unsigned long old_addr,
289 unsigned long new_addr)
293 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
295 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
297 * This must be implemented by the architecture.
298 * It is the way the ftrace direct_ops helper, when called
299 * via ftrace (because there's other callbacks besides the
300 * direct call), can inform the architecture's trampoline that this
301 * routine has a direct caller, and what the caller is.
303 * For example, in x86, it returns the direct caller
304 * callback function via the regs->orig_ax parameter.
305 * Then in the ftrace trampoline, if this is set, it makes
306 * the return from the trampoline jump to the direct caller
307 * instead of going back to the function it just traced.
309 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs,
310 unsigned long addr) { }
311 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
313 #ifdef CONFIG_STACK_TRACER
315 extern int stack_tracer_enabled;
317 int stack_trace_sysctl(struct ctl_table *table, int write,
318 void __user *buffer, size_t *lenp,
321 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
322 DECLARE_PER_CPU(int, disable_stack_tracer);
325 * stack_tracer_disable - temporarily disable the stack tracer
327 * There's a few locations (namely in RCU) where stack tracing
328 * cannot be executed. This function is used to disable stack
329 * tracing during those critical sections.
331 * This function must be called with preemption or interrupts
332 * disabled and stack_tracer_enable() must be called shortly after
333 * while preemption or interrupts are still disabled.
335 static inline void stack_tracer_disable(void)
337 /* Preemption or interupts must be disabled */
338 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
339 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
340 this_cpu_inc(disable_stack_tracer);
344 * stack_tracer_enable - re-enable the stack tracer
346 * After stack_tracer_disable() is called, stack_tracer_enable()
347 * must be called shortly afterward.
349 static inline void stack_tracer_enable(void)
351 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
352 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
353 this_cpu_dec(disable_stack_tracer);
356 static inline void stack_tracer_disable(void) { }
357 static inline void stack_tracer_enable(void) { }
360 #ifdef CONFIG_DYNAMIC_FTRACE
362 int ftrace_arch_code_modify_prepare(void);
363 int ftrace_arch_code_modify_post_process(void);
365 enum ftrace_bug_type {
372 extern enum ftrace_bug_type ftrace_bug_type;
375 * Archs can set this to point to a variable that holds the value that was
376 * expected at the call site before calling ftrace_bug().
378 extern const void *ftrace_expected;
380 void ftrace_bug(int err, struct dyn_ftrace *rec);
384 extern int ftrace_text_reserved(const void *start, const void *end);
386 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
388 bool is_ftrace_trampoline(unsigned long addr);
391 * The dyn_ftrace record's flags field is split into two parts.
392 * the first part which is '0-FTRACE_REF_MAX' is a counter of
393 * the number of callbacks that have registered the function that
394 * the dyn_ftrace descriptor represents.
396 * The second part is a mask:
397 * ENABLED - the function is being traced
398 * REGS - the record wants the function to save regs
399 * REGS_EN - the function is set up to save regs.
400 * IPMODIFY - the record allows for the IP address to be changed.
401 * DISABLED - the record is not ready to be touched yet
402 * DIRECT - there is a direct function to call
404 * When a new ftrace_ops is registered and wants a function to save
405 * pt_regs, the rec->flag REGS is set. When the function has been
406 * set up to save regs, the REG_EN flag is set. Once a function
407 * starts saving regs it will do so until all ftrace_ops are removed
408 * from tracing that function.
411 FTRACE_FL_ENABLED = (1UL << 31),
412 FTRACE_FL_REGS = (1UL << 30),
413 FTRACE_FL_REGS_EN = (1UL << 29),
414 FTRACE_FL_TRAMP = (1UL << 28),
415 FTRACE_FL_TRAMP_EN = (1UL << 27),
416 FTRACE_FL_IPMODIFY = (1UL << 26),
417 FTRACE_FL_DISABLED = (1UL << 25),
418 FTRACE_FL_DIRECT = (1UL << 24),
419 FTRACE_FL_DIRECT_EN = (1UL << 23),
422 #define FTRACE_REF_MAX_SHIFT 23
423 #define FTRACE_FL_BITS 9
424 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1)
425 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
426 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
428 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK)
431 unsigned long ip; /* address of mcount call-site */
433 struct dyn_arch_ftrace arch;
436 int ftrace_force_update(void);
437 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
438 int remove, int reset);
439 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
441 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
443 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
444 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
445 void ftrace_free_filter(struct ftrace_ops *ops);
446 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
449 FTRACE_UPDATE_CALLS = (1 << 0),
450 FTRACE_DISABLE_CALLS = (1 << 1),
451 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
452 FTRACE_START_FUNC_RET = (1 << 3),
453 FTRACE_STOP_FUNC_RET = (1 << 4),
454 FTRACE_MAY_SLEEP = (1 << 5),
458 * The FTRACE_UPDATE_* enum is used to pass information back
459 * from the ftrace_update_record() and ftrace_test_record()
460 * functions. These are called by the code update routines
461 * to find out what is to be done for a given function.
463 * IGNORE - The function is already what we want it to be
464 * MAKE_CALL - Start tracing the function
465 * MODIFY_CALL - Stop saving regs for the function
466 * MAKE_NOP - Stop tracing the function
469 FTRACE_UPDATE_IGNORE,
470 FTRACE_UPDATE_MAKE_CALL,
471 FTRACE_UPDATE_MODIFY_CALL,
472 FTRACE_UPDATE_MAKE_NOP,
476 FTRACE_ITER_FILTER = (1 << 0),
477 FTRACE_ITER_NOTRACE = (1 << 1),
478 FTRACE_ITER_PRINTALL = (1 << 2),
479 FTRACE_ITER_DO_PROBES = (1 << 3),
480 FTRACE_ITER_PROBE = (1 << 4),
481 FTRACE_ITER_MOD = (1 << 5),
482 FTRACE_ITER_ENABLED = (1 << 6),
485 void arch_ftrace_update_code(int command);
486 void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
487 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
488 void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
490 struct ftrace_rec_iter;
492 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
493 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
494 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
496 #define for_ftrace_rec_iter(iter) \
497 for (iter = ftrace_rec_iter_start(); \
499 iter = ftrace_rec_iter_next(iter))
502 int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
503 int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
504 void ftrace_run_stop_machine(int command);
505 unsigned long ftrace_location(unsigned long ip);
506 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
507 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
508 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
510 extern ftrace_func_t ftrace_trace_function;
512 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
513 struct inode *inode, struct file *file);
514 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
515 size_t cnt, loff_t *ppos);
516 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
517 size_t cnt, loff_t *ppos);
518 int ftrace_regex_release(struct inode *inode, struct file *file);
521 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
523 /* defined in arch */
524 extern int ftrace_ip_converted(unsigned long ip);
525 extern int ftrace_dyn_arch_init(void);
526 extern void ftrace_replace_code(int enable);
527 extern int ftrace_update_ftrace_func(ftrace_func_t func);
528 extern void ftrace_caller(void);
529 extern void ftrace_regs_caller(void);
530 extern void ftrace_call(void);
531 extern void ftrace_regs_call(void);
532 extern void mcount_call(void);
534 void ftrace_modify_all_code(int command);
537 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
540 #ifndef FTRACE_GRAPH_ADDR
541 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
544 #ifndef FTRACE_REGS_ADDR
545 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
546 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
548 # define FTRACE_REGS_ADDR FTRACE_ADDR
553 * If an arch would like functions that are only traced
554 * by the function graph tracer to jump directly to its own
555 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
556 * to be that address to jump to.
558 #ifndef FTRACE_GRAPH_TRAMP_ADDR
559 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
562 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
563 extern void ftrace_graph_caller(void);
564 extern int ftrace_enable_ftrace_graph_caller(void);
565 extern int ftrace_disable_ftrace_graph_caller(void);
567 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
568 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
572 * ftrace_make_nop - convert code into nop
573 * @mod: module structure if called by module load initialization
574 * @rec: the call site record (e.g. mcount/fentry)
575 * @addr: the address that the call site should be calling
577 * This is a very sensitive operation and great care needs
578 * to be taken by the arch. The operation should carefully
579 * read the location, check to see if what is read is indeed
580 * what we expect it to be, and then on success of the compare,
581 * it should write to the location.
583 * The code segment at @rec->ip should be a caller to @addr
587 * -EFAULT on error reading the location
588 * -EINVAL on a failed compare of the contents
589 * -EPERM on error writing to the location
590 * Any other value will be considered a failure.
592 extern int ftrace_make_nop(struct module *mod,
593 struct dyn_ftrace *rec, unsigned long addr);
597 * ftrace_init_nop - initialize a nop call site
598 * @mod: module structure if called by module load initialization
599 * @rec: the call site record (e.g. mcount/fentry)
601 * This is a very sensitive operation and great care needs
602 * to be taken by the arch. The operation should carefully
603 * read the location, check to see if what is read is indeed
604 * what we expect it to be, and then on success of the compare,
605 * it should write to the location.
607 * The code segment at @rec->ip should contain the contents created by
612 * -EFAULT on error reading the location
613 * -EINVAL on a failed compare of the contents
614 * -EPERM on error writing to the location
615 * Any other value will be considered a failure.
617 #ifndef ftrace_init_nop
618 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
620 return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
625 * ftrace_make_call - convert a nop call site into a call to addr
626 * @rec: the call site record (e.g. mcount/fentry)
627 * @addr: the address that the call site should call
629 * This is a very sensitive operation and great care needs
630 * to be taken by the arch. The operation should carefully
631 * read the location, check to see if what is read is indeed
632 * what we expect it to be, and then on success of the compare,
633 * it should write to the location.
635 * The code segment at @rec->ip should be a nop
639 * -EFAULT on error reading the location
640 * -EINVAL on a failed compare of the contents
641 * -EPERM on error writing to the location
642 * Any other value will be considered a failure.
644 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
646 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
648 * ftrace_modify_call - convert from one addr to another (no nop)
649 * @rec: the call site record (e.g. mcount/fentry)
650 * @old_addr: the address expected to be currently called to
651 * @addr: the address to change to
653 * This is a very sensitive operation and great care needs
654 * to be taken by the arch. The operation should carefully
655 * read the location, check to see if what is read is indeed
656 * what we expect it to be, and then on success of the compare,
657 * it should write to the location.
659 * The code segment at @rec->ip should be a caller to @old_addr
663 * -EFAULT on error reading the location
664 * -EINVAL on a failed compare of the contents
665 * -EPERM on error writing to the location
666 * Any other value will be considered a failure.
668 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
671 /* Should never be called */
672 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
679 /* May be defined in arch */
680 extern int ftrace_arch_read_dyn_info(char *buf, int size);
682 extern int skip_trace(unsigned long ip);
683 extern void ftrace_module_init(struct module *mod);
684 extern void ftrace_module_enable(struct module *mod);
685 extern void ftrace_release_mod(struct module *mod);
687 extern void ftrace_disable_daemon(void);
688 extern void ftrace_enable_daemon(void);
689 #else /* CONFIG_DYNAMIC_FTRACE */
690 static inline int skip_trace(unsigned long ip) { return 0; }
691 static inline int ftrace_force_update(void) { return 0; }
692 static inline void ftrace_disable_daemon(void) { }
693 static inline void ftrace_enable_daemon(void) { }
694 static inline void ftrace_module_init(struct module *mod) { }
695 static inline void ftrace_module_enable(struct module *mod) { }
696 static inline void ftrace_release_mod(struct module *mod) { }
697 static inline int ftrace_text_reserved(const void *start, const void *end)
701 static inline unsigned long ftrace_location(unsigned long ip)
707 * Again users of functions that have ftrace_ops may not
708 * have them defined when ftrace is not enabled, but these
709 * functions may still be called. Use a macro instead of inline.
711 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
712 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
713 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
714 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
715 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
716 #define ftrace_free_filter(ops) do { } while (0)
717 #define ftrace_ops_set_global_filter(ops) do { } while (0)
719 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
720 size_t cnt, loff_t *ppos) { return -ENODEV; }
721 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
722 size_t cnt, loff_t *ppos) { return -ENODEV; }
724 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
726 static inline bool is_ftrace_trampoline(unsigned long addr)
730 #endif /* CONFIG_DYNAMIC_FTRACE */
732 /* totally disable ftrace - can not re-enable after this */
733 void ftrace_kill(void);
735 static inline void tracer_disable(void)
737 #ifdef CONFIG_FUNCTION_TRACER
743 * Ftrace disable/restore without lock. Some synchronization mechanism
744 * must be used to prevent ftrace_enabled to be changed between
747 static inline int __ftrace_enabled_save(void)
749 #ifdef CONFIG_FUNCTION_TRACER
750 int saved_ftrace_enabled = ftrace_enabled;
752 return saved_ftrace_enabled;
758 static inline void __ftrace_enabled_restore(int enabled)
760 #ifdef CONFIG_FUNCTION_TRACER
761 ftrace_enabled = enabled;
765 /* All archs should have this, but we define it for consistency */
766 #ifndef ftrace_return_address0
767 # define ftrace_return_address0 __builtin_return_address(0)
770 /* Archs may use other ways for ADDR1 and beyond */
771 #ifndef ftrace_return_address
772 # ifdef CONFIG_FRAME_POINTER
773 # define ftrace_return_address(n) __builtin_return_address(n)
775 # define ftrace_return_address(n) 0UL
779 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
780 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
781 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
782 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
783 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
784 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
785 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
787 static inline unsigned long get_lock_parent_ip(void)
789 unsigned long addr = CALLER_ADDR0;
791 if (!in_lock_functions(addr))
794 if (!in_lock_functions(addr))
799 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
800 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
801 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
804 * Use defines instead of static inlines because some arches will make code out
805 * of the CALLER_ADDR, when we really want these to be a real nop.
807 # define trace_preempt_on(a0, a1) do { } while (0)
808 # define trace_preempt_off(a0, a1) do { } while (0)
811 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
812 extern void ftrace_init(void);
813 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
814 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
816 #define FTRACE_CALLSITE_SECTION "__mcount_loc"
819 static inline void ftrace_init(void) { }
823 * Structure that defines an entry function trace.
824 * It's already packed but the attribute "packed" is needed
825 * to remove extra padding at the end.
827 struct ftrace_graph_ent {
828 unsigned long func; /* Current function */
833 * Structure that defines a return function trace.
834 * It's already packed but the attribute "packed" is needed
835 * to remove extra padding at the end.
837 struct ftrace_graph_ret {
838 unsigned long func; /* Current function */
839 /* Number of functions that overran the depth limit for current task */
840 unsigned long overrun;
841 unsigned long long calltime;
842 unsigned long long rettime;
846 /* Type of the callback handlers for tracing function graph*/
847 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
848 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
850 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
852 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
855 trace_func_graph_ent_t entryfunc;
856 trace_func_graph_ret_t retfunc;
860 * Stack of return addresses for functions
862 * Used in struct thread_info
864 struct ftrace_ret_stack {
867 unsigned long long calltime;
868 #ifdef CONFIG_FUNCTION_PROFILER
869 unsigned long long subtime;
871 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
874 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
880 * Primary handler of a function return.
881 * It relays on ftrace_return_to_handler.
882 * Defined in entry_32/64.S
884 extern void return_to_handler(void);
887 function_graph_enter(unsigned long ret, unsigned long func,
888 unsigned long frame_pointer, unsigned long *retp);
890 struct ftrace_ret_stack *
891 ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
893 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
894 unsigned long ret, unsigned long *retp);
897 * Sometimes we don't want to trace a function with the function
898 * graph tracer but we want them to keep traced by the usual function
899 * tracer if the function graph tracer is not configured.
901 #define __notrace_funcgraph notrace
903 #define FTRACE_RETFUNC_DEPTH 50
904 #define FTRACE_RETSTACK_ALLOC_SIZE 32
906 extern int register_ftrace_graph(struct fgraph_ops *ops);
907 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
909 extern bool ftrace_graph_is_dead(void);
910 extern void ftrace_graph_stop(void);
912 /* The current handlers in use */
913 extern trace_func_graph_ret_t ftrace_graph_return;
914 extern trace_func_graph_ent_t ftrace_graph_entry;
916 extern void ftrace_graph_init_task(struct task_struct *t);
917 extern void ftrace_graph_exit_task(struct task_struct *t);
918 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
920 static inline void pause_graph_tracing(void)
922 atomic_inc(¤t->tracing_graph_pause);
925 static inline void unpause_graph_tracing(void)
927 atomic_dec(¤t->tracing_graph_pause);
929 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
931 #define __notrace_funcgraph
933 static inline void ftrace_graph_init_task(struct task_struct *t) { }
934 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
935 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
937 /* Define as macros as fgraph_ops may not be defined */
938 #define register_ftrace_graph(ops) ({ -1; })
939 #define unregister_ftrace_graph(ops) do { } while (0)
941 static inline unsigned long
942 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
948 static inline void pause_graph_tracing(void) { }
949 static inline void unpause_graph_tracing(void) { }
950 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
952 #ifdef CONFIG_TRACING
954 /* flags for current->trace */
956 TSK_TRACE_FL_TRACE_BIT = 0,
957 TSK_TRACE_FL_GRAPH_BIT = 1,
960 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
961 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
964 static inline void set_tsk_trace_trace(struct task_struct *tsk)
966 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
969 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
971 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
974 static inline int test_tsk_trace_trace(struct task_struct *tsk)
976 return tsk->trace & TSK_TRACE_FL_TRACE;
979 static inline void set_tsk_trace_graph(struct task_struct *tsk)
981 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
984 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
986 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
989 static inline int test_tsk_trace_graph(struct task_struct *tsk)
991 return tsk->trace & TSK_TRACE_FL_GRAPH;
994 enum ftrace_dump_mode;
996 extern enum ftrace_dump_mode ftrace_dump_on_oops;
997 extern int tracepoint_printk;
999 extern void disable_trace_on_warning(void);
1000 extern int __disable_trace_on_warning;
1002 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
1003 void __user *buffer, size_t *lenp,
1006 #else /* CONFIG_TRACING */
1007 static inline void disable_trace_on_warning(void) { }
1008 #endif /* CONFIG_TRACING */
1010 #ifdef CONFIG_FTRACE_SYSCALLS
1012 unsigned long arch_syscall_addr(int nr);
1014 #endif /* CONFIG_FTRACE_SYSCALLS */
1016 #endif /* _LINUX_FTRACE_H */