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;
213 extern struct ftrace_ops __rcu *ftrace_ops_list;
214 extern struct ftrace_ops ftrace_list_end;
217 * Traverse the ftrace_global_list, invoking all entries. The reason that we
218 * can use rcu_dereference_raw_check() is that elements removed from this list
219 * are simply leaked, so there is no need to interact with a grace-period
220 * mechanism. The rcu_dereference_raw_check() calls are needed to handle
221 * concurrent insertions into the ftrace_global_list.
223 * Silly Alpha and silly pointer-speculation compiler optimizations!
225 #define do_for_each_ftrace_op(op, list) \
226 op = rcu_dereference_raw_check(list); \
230 * Optimized for just a single item in the list (as that is the normal case).
232 #define while_for_each_ftrace_op(op) \
233 while (likely(op = rcu_dereference_raw_check((op)->next)) && \
234 unlikely((op) != &ftrace_list_end))
237 * Type of the current tracing.
239 enum ftrace_tracing_type_t {
240 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
241 FTRACE_TYPE_RETURN, /* Hook the return of the function */
244 /* Current tracing type, default is FTRACE_TYPE_ENTER */
245 extern enum ftrace_tracing_type_t ftrace_tracing_type;
248 * The ftrace_ops must be a static and should also
249 * be read_mostly. These functions do modify read_mostly variables
250 * so use them sparely. Never free an ftrace_op or modify the
251 * next pointer after it has been registered. Even after unregistering
252 * it, the next pointer may still be used internally.
254 int register_ftrace_function(struct ftrace_ops *ops);
255 int unregister_ftrace_function(struct ftrace_ops *ops);
257 extern void ftrace_stub(unsigned long a0, unsigned long a1,
258 struct ftrace_ops *op, struct pt_regs *regs);
260 #else /* !CONFIG_FUNCTION_TRACER */
262 * (un)register_ftrace_function must be a macro since the ops parameter
263 * must not be evaluated.
265 #define register_ftrace_function(ops) ({ 0; })
266 #define unregister_ftrace_function(ops) ({ 0; })
267 static inline void ftrace_kill(void) { }
268 static inline void ftrace_free_init_mem(void) { }
269 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
270 #endif /* CONFIG_FUNCTION_TRACER */
272 struct ftrace_func_entry {
273 struct hlist_node hlist;
275 unsigned long direct; /* for direct lookup only */
280 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
281 extern int ftrace_direct_func_count;
282 int register_ftrace_direct(unsigned long ip, unsigned long addr);
283 int unregister_ftrace_direct(unsigned long ip, unsigned long addr);
284 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr);
285 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr);
286 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);
290 unsigned long ftrace_find_rec_direct(unsigned long ip);
292 # define ftrace_direct_func_count 0
293 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
297 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
301 static inline int modify_ftrace_direct(unsigned long ip,
302 unsigned long old_addr, unsigned long new_addr)
306 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
310 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
311 struct dyn_ftrace *rec,
312 unsigned long old_addr,
313 unsigned long new_addr)
317 static inline unsigned long ftrace_find_rec_direct(unsigned long ip)
321 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
323 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
325 * This must be implemented by the architecture.
326 * It is the way the ftrace direct_ops helper, when called
327 * via ftrace (because there's other callbacks besides the
328 * direct call), can inform the architecture's trampoline that this
329 * routine has a direct caller, and what the caller is.
331 * For example, in x86, it returns the direct caller
332 * callback function via the regs->orig_ax parameter.
333 * Then in the ftrace trampoline, if this is set, it makes
334 * the return from the trampoline jump to the direct caller
335 * instead of going back to the function it just traced.
337 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs,
338 unsigned long addr) { }
339 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
341 #ifdef CONFIG_STACK_TRACER
343 extern int stack_tracer_enabled;
345 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer,
346 size_t *lenp, loff_t *ppos);
348 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
349 DECLARE_PER_CPU(int, disable_stack_tracer);
352 * stack_tracer_disable - temporarily disable the stack tracer
354 * There's a few locations (namely in RCU) where stack tracing
355 * cannot be executed. This function is used to disable stack
356 * tracing during those critical sections.
358 * This function must be called with preemption or interrupts
359 * disabled and stack_tracer_enable() must be called shortly after
360 * while preemption or interrupts are still disabled.
362 static inline void stack_tracer_disable(void)
364 /* Preemption or interupts must be disabled */
365 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
366 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
367 this_cpu_inc(disable_stack_tracer);
371 * stack_tracer_enable - re-enable the stack tracer
373 * After stack_tracer_disable() is called, stack_tracer_enable()
374 * must be called shortly afterward.
376 static inline void stack_tracer_enable(void)
378 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
379 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
380 this_cpu_dec(disable_stack_tracer);
383 static inline void stack_tracer_disable(void) { }
384 static inline void stack_tracer_enable(void) { }
387 #ifdef CONFIG_DYNAMIC_FTRACE
389 int ftrace_arch_code_modify_prepare(void);
390 int ftrace_arch_code_modify_post_process(void);
392 enum ftrace_bug_type {
399 extern enum ftrace_bug_type ftrace_bug_type;
402 * Archs can set this to point to a variable that holds the value that was
403 * expected at the call site before calling ftrace_bug().
405 extern const void *ftrace_expected;
407 void ftrace_bug(int err, struct dyn_ftrace *rec);
411 extern int ftrace_text_reserved(const void *start, const void *end);
413 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
415 bool is_ftrace_trampoline(unsigned long addr);
418 * The dyn_ftrace record's flags field is split into two parts.
419 * the first part which is '0-FTRACE_REF_MAX' is a counter of
420 * the number of callbacks that have registered the function that
421 * the dyn_ftrace descriptor represents.
423 * The second part is a mask:
424 * ENABLED - the function is being traced
425 * REGS - the record wants the function to save regs
426 * REGS_EN - the function is set up to save regs.
427 * IPMODIFY - the record allows for the IP address to be changed.
428 * DISABLED - the record is not ready to be touched yet
429 * DIRECT - there is a direct function to call
431 * When a new ftrace_ops is registered and wants a function to save
432 * pt_regs, the rec->flag REGS is set. When the function has been
433 * set up to save regs, the REG_EN flag is set. Once a function
434 * starts saving regs it will do so until all ftrace_ops are removed
435 * from tracing that function.
438 FTRACE_FL_ENABLED = (1UL << 31),
439 FTRACE_FL_REGS = (1UL << 30),
440 FTRACE_FL_REGS_EN = (1UL << 29),
441 FTRACE_FL_TRAMP = (1UL << 28),
442 FTRACE_FL_TRAMP_EN = (1UL << 27),
443 FTRACE_FL_IPMODIFY = (1UL << 26),
444 FTRACE_FL_DISABLED = (1UL << 25),
445 FTRACE_FL_DIRECT = (1UL << 24),
446 FTRACE_FL_DIRECT_EN = (1UL << 23),
449 #define FTRACE_REF_MAX_SHIFT 23
450 #define FTRACE_FL_BITS 9
451 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1)
452 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
453 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
455 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK)
458 unsigned long ip; /* address of mcount call-site */
460 struct dyn_arch_ftrace arch;
463 int ftrace_force_update(void);
464 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
465 int remove, int reset);
466 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
468 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
470 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
471 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
472 void ftrace_free_filter(struct ftrace_ops *ops);
473 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
476 FTRACE_UPDATE_CALLS = (1 << 0),
477 FTRACE_DISABLE_CALLS = (1 << 1),
478 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
479 FTRACE_START_FUNC_RET = (1 << 3),
480 FTRACE_STOP_FUNC_RET = (1 << 4),
481 FTRACE_MAY_SLEEP = (1 << 5),
485 * The FTRACE_UPDATE_* enum is used to pass information back
486 * from the ftrace_update_record() and ftrace_test_record()
487 * functions. These are called by the code update routines
488 * to find out what is to be done for a given function.
490 * IGNORE - The function is already what we want it to be
491 * MAKE_CALL - Start tracing the function
492 * MODIFY_CALL - Stop saving regs for the function
493 * MAKE_NOP - Stop tracing the function
496 FTRACE_UPDATE_IGNORE,
497 FTRACE_UPDATE_MAKE_CALL,
498 FTRACE_UPDATE_MODIFY_CALL,
499 FTRACE_UPDATE_MAKE_NOP,
503 FTRACE_ITER_FILTER = (1 << 0),
504 FTRACE_ITER_NOTRACE = (1 << 1),
505 FTRACE_ITER_PRINTALL = (1 << 2),
506 FTRACE_ITER_DO_PROBES = (1 << 3),
507 FTRACE_ITER_PROBE = (1 << 4),
508 FTRACE_ITER_MOD = (1 << 5),
509 FTRACE_ITER_ENABLED = (1 << 6),
512 void arch_ftrace_update_code(int command);
513 void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
514 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
515 void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
517 struct ftrace_rec_iter;
519 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
520 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
521 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
523 #define for_ftrace_rec_iter(iter) \
524 for (iter = ftrace_rec_iter_start(); \
526 iter = ftrace_rec_iter_next(iter))
529 int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
530 int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
531 void ftrace_run_stop_machine(int command);
532 unsigned long ftrace_location(unsigned long ip);
533 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
534 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
535 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
537 extern ftrace_func_t ftrace_trace_function;
539 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
540 struct inode *inode, struct file *file);
541 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
542 size_t cnt, loff_t *ppos);
543 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
544 size_t cnt, loff_t *ppos);
545 int ftrace_regex_release(struct inode *inode, struct file *file);
548 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
550 /* defined in arch */
551 extern int ftrace_ip_converted(unsigned long ip);
552 extern int ftrace_dyn_arch_init(void);
553 extern void ftrace_replace_code(int enable);
554 extern int ftrace_update_ftrace_func(ftrace_func_t func);
555 extern void ftrace_caller(void);
556 extern void ftrace_regs_caller(void);
557 extern void ftrace_call(void);
558 extern void ftrace_regs_call(void);
559 extern void mcount_call(void);
561 void ftrace_modify_all_code(int command);
564 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
567 #ifndef FTRACE_GRAPH_ADDR
568 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
571 #ifndef FTRACE_REGS_ADDR
572 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
573 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
575 # define FTRACE_REGS_ADDR FTRACE_ADDR
580 * If an arch would like functions that are only traced
581 * by the function graph tracer to jump directly to its own
582 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
583 * to be that address to jump to.
585 #ifndef FTRACE_GRAPH_TRAMP_ADDR
586 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
589 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
590 extern void ftrace_graph_caller(void);
591 extern int ftrace_enable_ftrace_graph_caller(void);
592 extern int ftrace_disable_ftrace_graph_caller(void);
594 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
595 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
599 * ftrace_make_nop - convert code into nop
600 * @mod: module structure if called by module load initialization
601 * @rec: the call site record (e.g. mcount/fentry)
602 * @addr: the address that the call site should be calling
604 * This is a very sensitive operation and great care needs
605 * to be taken by the arch. The operation should carefully
606 * read the location, check to see if what is read is indeed
607 * what we expect it to be, and then on success of the compare,
608 * it should write to the location.
610 * The code segment at @rec->ip should be a caller to @addr
614 * -EFAULT on error reading the location
615 * -EINVAL on a failed compare of the contents
616 * -EPERM on error writing to the location
617 * Any other value will be considered a failure.
619 extern int ftrace_make_nop(struct module *mod,
620 struct dyn_ftrace *rec, unsigned long addr);
624 * ftrace_init_nop - initialize a nop call site
625 * @mod: module structure if called by module load initialization
626 * @rec: the call site record (e.g. mcount/fentry)
628 * This is a very sensitive operation and great care needs
629 * to be taken by the arch. The operation should carefully
630 * read the location, check to see if what is read is indeed
631 * what we expect it to be, and then on success of the compare,
632 * it should write to the location.
634 * The code segment at @rec->ip should contain the contents created by
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 #ifndef ftrace_init_nop
645 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
647 return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
652 * ftrace_make_call - convert a nop call site into a call to addr
653 * @rec: the call site record (e.g. mcount/fentry)
654 * @addr: the address that the call site should call
656 * This is a very sensitive operation and great care needs
657 * to be taken by the arch. The operation should carefully
658 * read the location, check to see if what is read is indeed
659 * what we expect it to be, and then on success of the compare,
660 * it should write to the location.
662 * The code segment at @rec->ip should be a nop
666 * -EFAULT on error reading the location
667 * -EINVAL on a failed compare of the contents
668 * -EPERM on error writing to the location
669 * Any other value will be considered a failure.
671 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
673 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
675 * ftrace_modify_call - convert from one addr to another (no nop)
676 * @rec: the call site record (e.g. mcount/fentry)
677 * @old_addr: the address expected to be currently called to
678 * @addr: the address to change to
680 * This is a very sensitive operation and great care needs
681 * to be taken by the arch. The operation should carefully
682 * read the location, check to see if what is read is indeed
683 * what we expect it to be, and then on success of the compare,
684 * it should write to the location.
686 * The code segment at @rec->ip should be a caller to @old_addr
690 * -EFAULT on error reading the location
691 * -EINVAL on a failed compare of the contents
692 * -EPERM on error writing to the location
693 * Any other value will be considered a failure.
695 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
698 /* Should never be called */
699 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
706 /* May be defined in arch */
707 extern int ftrace_arch_read_dyn_info(char *buf, int size);
709 extern int skip_trace(unsigned long ip);
710 extern void ftrace_module_init(struct module *mod);
711 extern void ftrace_module_enable(struct module *mod);
712 extern void ftrace_release_mod(struct module *mod);
714 extern void ftrace_disable_daemon(void);
715 extern void ftrace_enable_daemon(void);
716 #else /* CONFIG_DYNAMIC_FTRACE */
717 static inline int skip_trace(unsigned long ip) { return 0; }
718 static inline int ftrace_force_update(void) { return 0; }
719 static inline void ftrace_disable_daemon(void) { }
720 static inline void ftrace_enable_daemon(void) { }
721 static inline void ftrace_module_init(struct module *mod) { }
722 static inline void ftrace_module_enable(struct module *mod) { }
723 static inline void ftrace_release_mod(struct module *mod) { }
724 static inline int ftrace_text_reserved(const void *start, const void *end)
728 static inline unsigned long ftrace_location(unsigned long ip)
734 * Again users of functions that have ftrace_ops may not
735 * have them defined when ftrace is not enabled, but these
736 * functions may still be called. Use a macro instead of inline.
738 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
739 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
740 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
741 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
742 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
743 #define ftrace_free_filter(ops) do { } while (0)
744 #define ftrace_ops_set_global_filter(ops) do { } while (0)
746 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
747 size_t cnt, loff_t *ppos) { return -ENODEV; }
748 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
749 size_t cnt, loff_t *ppos) { return -ENODEV; }
751 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
753 static inline bool is_ftrace_trampoline(unsigned long addr)
757 #endif /* CONFIG_DYNAMIC_FTRACE */
759 /* totally disable ftrace - can not re-enable after this */
760 void ftrace_kill(void);
762 static inline void tracer_disable(void)
764 #ifdef CONFIG_FUNCTION_TRACER
770 * Ftrace disable/restore without lock. Some synchronization mechanism
771 * must be used to prevent ftrace_enabled to be changed between
774 static inline int __ftrace_enabled_save(void)
776 #ifdef CONFIG_FUNCTION_TRACER
777 int saved_ftrace_enabled = ftrace_enabled;
779 return saved_ftrace_enabled;
785 static inline void __ftrace_enabled_restore(int enabled)
787 #ifdef CONFIG_FUNCTION_TRACER
788 ftrace_enabled = enabled;
792 /* All archs should have this, but we define it for consistency */
793 #ifndef ftrace_return_address0
794 # define ftrace_return_address0 __builtin_return_address(0)
797 /* Archs may use other ways for ADDR1 and beyond */
798 #ifndef ftrace_return_address
799 # ifdef CONFIG_FRAME_POINTER
800 # define ftrace_return_address(n) __builtin_return_address(n)
802 # define ftrace_return_address(n) 0UL
806 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
807 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
808 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
809 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
810 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
811 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
812 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
814 static inline unsigned long get_lock_parent_ip(void)
816 unsigned long addr = CALLER_ADDR0;
818 if (!in_lock_functions(addr))
821 if (!in_lock_functions(addr))
826 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
827 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
828 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
831 * Use defines instead of static inlines because some arches will make code out
832 * of the CALLER_ADDR, when we really want these to be a real nop.
834 # define trace_preempt_on(a0, a1) do { } while (0)
835 # define trace_preempt_off(a0, a1) do { } while (0)
838 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
839 extern void ftrace_init(void);
840 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
841 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
843 #define FTRACE_CALLSITE_SECTION "__mcount_loc"
846 static inline void ftrace_init(void) { }
850 * Structure that defines an entry function trace.
851 * It's already packed but the attribute "packed" is needed
852 * to remove extra padding at the end.
854 struct ftrace_graph_ent {
855 unsigned long func; /* Current function */
860 * Structure that defines a return function trace.
861 * It's already packed but the attribute "packed" is needed
862 * to remove extra padding at the end.
864 struct ftrace_graph_ret {
865 unsigned long func; /* Current function */
866 /* Number of functions that overran the depth limit for current task */
867 unsigned long overrun;
868 unsigned long long calltime;
869 unsigned long long rettime;
873 /* Type of the callback handlers for tracing function graph*/
874 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
875 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
877 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
879 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
882 trace_func_graph_ent_t entryfunc;
883 trace_func_graph_ret_t retfunc;
887 * Stack of return addresses for functions
889 * Used in struct thread_info
891 struct ftrace_ret_stack {
894 unsigned long long calltime;
895 #ifdef CONFIG_FUNCTION_PROFILER
896 unsigned long long subtime;
898 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
901 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
907 * Primary handler of a function return.
908 * It relays on ftrace_return_to_handler.
909 * Defined in entry_32/64.S
911 extern void return_to_handler(void);
914 function_graph_enter(unsigned long ret, unsigned long func,
915 unsigned long frame_pointer, unsigned long *retp);
917 struct ftrace_ret_stack *
918 ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
920 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
921 unsigned long ret, unsigned long *retp);
924 * Sometimes we don't want to trace a function with the function
925 * graph tracer but we want them to keep traced by the usual function
926 * tracer if the function graph tracer is not configured.
928 #define __notrace_funcgraph notrace
930 #define FTRACE_RETFUNC_DEPTH 50
931 #define FTRACE_RETSTACK_ALLOC_SIZE 32
933 extern int register_ftrace_graph(struct fgraph_ops *ops);
934 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
936 extern bool ftrace_graph_is_dead(void);
937 extern void ftrace_graph_stop(void);
939 /* The current handlers in use */
940 extern trace_func_graph_ret_t ftrace_graph_return;
941 extern trace_func_graph_ent_t ftrace_graph_entry;
943 extern void ftrace_graph_init_task(struct task_struct *t);
944 extern void ftrace_graph_exit_task(struct task_struct *t);
945 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
947 static inline void pause_graph_tracing(void)
949 atomic_inc(¤t->tracing_graph_pause);
952 static inline void unpause_graph_tracing(void)
954 atomic_dec(¤t->tracing_graph_pause);
956 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
958 #define __notrace_funcgraph
960 static inline void ftrace_graph_init_task(struct task_struct *t) { }
961 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
962 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
964 /* Define as macros as fgraph_ops may not be defined */
965 #define register_ftrace_graph(ops) ({ -1; })
966 #define unregister_ftrace_graph(ops) do { } while (0)
968 static inline unsigned long
969 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
975 static inline void pause_graph_tracing(void) { }
976 static inline void unpause_graph_tracing(void) { }
977 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
979 #ifdef CONFIG_TRACING
981 /* flags for current->trace */
983 TSK_TRACE_FL_TRACE_BIT = 0,
984 TSK_TRACE_FL_GRAPH_BIT = 1,
987 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
988 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
991 static inline void set_tsk_trace_trace(struct task_struct *tsk)
993 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
996 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
998 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
1001 static inline int test_tsk_trace_trace(struct task_struct *tsk)
1003 return tsk->trace & TSK_TRACE_FL_TRACE;
1006 static inline void set_tsk_trace_graph(struct task_struct *tsk)
1008 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
1011 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
1013 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
1016 static inline int test_tsk_trace_graph(struct task_struct *tsk)
1018 return tsk->trace & TSK_TRACE_FL_GRAPH;
1021 enum ftrace_dump_mode;
1023 extern enum ftrace_dump_mode ftrace_dump_on_oops;
1024 extern int tracepoint_printk;
1026 extern void disable_trace_on_warning(void);
1027 extern int __disable_trace_on_warning;
1029 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
1030 void *buffer, size_t *lenp, loff_t *ppos);
1032 #else /* CONFIG_TRACING */
1033 static inline void disable_trace_on_warning(void) { }
1034 #endif /* CONFIG_TRACING */
1036 #ifdef CONFIG_FTRACE_SYSCALLS
1038 unsigned long arch_syscall_addr(int nr);
1040 #endif /* CONFIG_FTRACE_SYSCALLS */
1042 #endif /* _LINUX_FTRACE_H */