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_recursion.h>
11 #include <linux/trace_clock.h>
12 #include <linux/jump_label.h>
13 #include <linux/kallsyms.h>
14 #include <linux/linkage.h>
15 #include <linux/bitops.h>
16 #include <linux/ptrace.h>
17 #include <linux/ktime.h>
18 #include <linux/sched.h>
19 #include <linux/types.h>
20 #include <linux/init.h>
23 #include <asm/ftrace.h>
26 * If the arch supports passing the variable contents of
27 * function_trace_op as the third parameter back from the
28 * mcount call, then the arch should define this as 1.
30 #ifndef ARCH_SUPPORTS_FTRACE_OPS
31 #define ARCH_SUPPORTS_FTRACE_OPS 0
35 extern void ftrace_boot_snapshot(void);
37 static inline void ftrace_boot_snapshot(void) { }
44 #ifdef CONFIG_FUNCTION_TRACER
46 * If the arch's mcount caller does not support all of ftrace's
47 * features, then it must call an indirect function that
48 * does. Or at least does enough to prevent any unwelcome side effects.
50 * Also define the function prototype that these architectures use
51 * to call the ftrace_ops_list_func().
53 #if !ARCH_SUPPORTS_FTRACE_OPS
54 # define FTRACE_FORCE_LIST_FUNC 1
55 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
57 # define FTRACE_FORCE_LIST_FUNC 0
58 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
59 struct ftrace_ops *op, struct ftrace_regs *fregs);
61 extern const struct ftrace_ops ftrace_nop_ops;
62 extern const struct ftrace_ops ftrace_list_ops;
63 struct ftrace_ops *ftrace_find_unique_ops(struct dyn_ftrace *rec);
64 #endif /* CONFIG_FUNCTION_TRACER */
66 /* Main tracing buffer and events set up */
68 void trace_init(void);
69 void early_trace_init(void);
71 static inline void trace_init(void) { }
72 static inline void early_trace_init(void) { }
77 struct ftrace_direct_func;
79 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
80 defined(CONFIG_DYNAMIC_FTRACE)
82 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
83 unsigned long *off, char **modname, char *sym);
85 static inline const char *
86 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
87 unsigned long *off, char **modname, char *sym)
93 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
94 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
95 char *type, char *name,
96 char *module_name, int *exported);
98 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
99 char *type, char *name,
100 char *module_name, int *exported)
106 #ifdef CONFIG_FUNCTION_TRACER
108 extern int ftrace_enabled;
110 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
115 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs)
118 * ftrace_regs_set_instruction_pointer() is to be defined by the architecture
119 * if to allow setting of the instruction pointer from the ftrace_regs when
120 * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching.
122 #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0)
123 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
125 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
130 return arch_ftrace_get_regs(fregs);
134 * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs.
135 * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs.
137 static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs)
139 if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS))
142 return ftrace_get_regs(fregs) != NULL;
145 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
146 #define ftrace_regs_get_instruction_pointer(fregs) \
147 instruction_pointer(ftrace_get_regs(fregs))
148 #define ftrace_regs_get_argument(fregs, n) \
149 regs_get_kernel_argument(ftrace_get_regs(fregs), n)
150 #define ftrace_regs_get_stack_pointer(fregs) \
151 kernel_stack_pointer(ftrace_get_regs(fregs))
152 #define ftrace_regs_return_value(fregs) \
153 regs_return_value(ftrace_get_regs(fregs))
154 #define ftrace_regs_set_return_value(fregs, ret) \
155 regs_set_return_value(ftrace_get_regs(fregs), ret)
156 #define ftrace_override_function_with_return(fregs) \
157 override_function_with_return(ftrace_get_regs(fregs))
158 #define ftrace_regs_query_register_offset(name) \
159 regs_query_register_offset(name)
162 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
163 struct ftrace_ops *op, struct ftrace_regs *fregs);
165 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
168 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
169 * set in the flags member.
170 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and
171 * IPMODIFY are a kind of attribute flags which can be set only before
172 * registering the ftrace_ops, and can not be modified while registered.
173 * Changing those attribute flags after registering ftrace_ops will
174 * cause unexpected results.
176 * ENABLED - set/unset when ftrace_ops is registered/unregistered
177 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
178 * allocated ftrace_ops which need special care
179 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
180 * and passed to the callback. If this flag is set, but the
181 * architecture does not support passing regs
182 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
183 * ftrace_ops will fail to register, unless the next flag
185 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
186 * handler can handle an arch that does not save regs
187 * (the handler tests if regs == NULL), then it can set
188 * this flag instead. It will not fail registering the ftrace_ops
189 * but, the regs field will be NULL if the arch does not support
190 * passing regs to the handler.
191 * Note, if this flag is set, the SAVE_REGS flag will automatically
192 * get set upon registering the ftrace_ops, if the arch supports it.
193 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure
194 * that the call back needs recursion protection. If it does
195 * not set this, then the ftrace infrastructure will assume
196 * that the callback can handle recursion on its own.
197 * STUB - The ftrace_ops is just a place holder.
198 * INITIALIZED - The ftrace_ops has already been initialized (first use time
199 * register_ftrace_function() is called, it will initialized the ops)
200 * DELETED - The ops are being deleted, do not let them be registered again.
201 * ADDING - The ops is in the process of being added.
202 * REMOVING - The ops is in the process of being removed.
203 * MODIFYING - The ops is in the process of changing its filter functions.
204 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
205 * The arch specific code sets this flag when it allocated a
206 * trampoline. This lets the arch know that it can update the
207 * trampoline in case the callback function changes.
208 * The ftrace_ops trampoline can be set by the ftrace users, and
209 * in such cases the arch must not modify it. Only the arch ftrace
210 * core code should set this flag.
211 * IPMODIFY - The ops can modify the IP register. This can only be set with
212 * SAVE_REGS. If another ops with this flag set is already registered
213 * for any of the functions that this ops will be registered for, then
214 * this ops will fail to register or set_filter_ip.
215 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
216 * RCU - Set when the ops can only be called when RCU is watching.
217 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
218 * PERMANENT - Set when the ops is permanent and should not be affected by
220 * DIRECT - Used by the direct ftrace_ops helper for direct functions
221 * (internal ftrace only, should not be used by others)
224 FTRACE_OPS_FL_ENABLED = BIT(0),
225 FTRACE_OPS_FL_DYNAMIC = BIT(1),
226 FTRACE_OPS_FL_SAVE_REGS = BIT(2),
227 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3),
228 FTRACE_OPS_FL_RECURSION = BIT(4),
229 FTRACE_OPS_FL_STUB = BIT(5),
230 FTRACE_OPS_FL_INITIALIZED = BIT(6),
231 FTRACE_OPS_FL_DELETED = BIT(7),
232 FTRACE_OPS_FL_ADDING = BIT(8),
233 FTRACE_OPS_FL_REMOVING = BIT(9),
234 FTRACE_OPS_FL_MODIFYING = BIT(10),
235 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11),
236 FTRACE_OPS_FL_IPMODIFY = BIT(12),
237 FTRACE_OPS_FL_PID = BIT(13),
238 FTRACE_OPS_FL_RCU = BIT(14),
239 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15),
240 FTRACE_OPS_FL_PERMANENT = BIT(16),
241 FTRACE_OPS_FL_DIRECT = BIT(17),
244 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
245 #define FTRACE_OPS_FL_SAVE_ARGS FTRACE_OPS_FL_SAVE_REGS
247 #define FTRACE_OPS_FL_SAVE_ARGS 0
251 * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes
252 * to a ftrace_ops. Note, the requests may fail.
254 * ENABLE_SHARE_IPMODIFY_SELF - enable a DIRECT ops to work on the same
255 * function as an ops with IPMODIFY. Called
256 * when the DIRECT ops is being registered.
257 * This is called with both direct_mutex and
258 * ftrace_lock are locked.
260 * ENABLE_SHARE_IPMODIFY_PEER - enable a DIRECT ops to work on the same
261 * function as an ops with IPMODIFY. Called
262 * when the other ops (the one with IPMODIFY)
263 * is being registered.
264 * This is called with direct_mutex locked.
266 * DISABLE_SHARE_IPMODIFY_PEER - disable a DIRECT ops to work on the same
267 * function as an ops with IPMODIFY. Called
268 * when the other ops (the one with IPMODIFY)
269 * is being unregistered.
270 * This is called with direct_mutex locked.
272 enum ftrace_ops_cmd {
273 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF,
274 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER,
275 FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER,
279 * For most ftrace_ops_cmd,
282 * Negative on failure. The return value is dependent on the
285 typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd cmd);
287 #ifdef CONFIG_DYNAMIC_FTRACE
288 /* The hash used to know what functions callbacks trace */
289 struct ftrace_ops_hash {
290 struct ftrace_hash __rcu *notrace_hash;
291 struct ftrace_hash __rcu *filter_hash;
292 struct mutex regex_lock;
295 void ftrace_free_init_mem(void);
296 void ftrace_free_mem(struct module *mod, void *start, void *end);
298 static inline void ftrace_free_init_mem(void)
300 ftrace_boot_snapshot();
302 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
306 * Note, ftrace_ops can be referenced outside of RCU protection, unless
307 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
308 * core data, the unregistering of it will perform a scheduling on all CPUs
309 * to make sure that there are no more users. Depending on the load of the
310 * system that may take a bit of time.
312 * Any private data added must also take care not to be freed and if private
313 * data is added to a ftrace_ops that is in core code, the user of the
314 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
318 struct ftrace_ops __rcu *next;
321 ftrace_func_t saved_func;
322 #ifdef CONFIG_DYNAMIC_FTRACE
323 struct ftrace_ops_hash local_hash;
324 struct ftrace_ops_hash *func_hash;
325 struct ftrace_ops_hash old_hash;
326 unsigned long trampoline;
327 unsigned long trampoline_size;
328 struct list_head list;
329 ftrace_ops_func_t ops_func;
330 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
331 unsigned long direct_call;
336 extern struct ftrace_ops __rcu *ftrace_ops_list;
337 extern struct ftrace_ops ftrace_list_end;
340 * Traverse the ftrace_ops_list, invoking all entries. The reason that we
341 * can use rcu_dereference_raw_check() is that elements removed from this list
342 * are simply leaked, so there is no need to interact with a grace-period
343 * mechanism. The rcu_dereference_raw_check() calls are needed to handle
344 * concurrent insertions into the ftrace_ops_list.
346 * Silly Alpha and silly pointer-speculation compiler optimizations!
348 #define do_for_each_ftrace_op(op, list) \
349 op = rcu_dereference_raw_check(list); \
353 * Optimized for just a single item in the list (as that is the normal case).
355 #define while_for_each_ftrace_op(op) \
356 while (likely(op = rcu_dereference_raw_check((op)->next)) && \
357 unlikely((op) != &ftrace_list_end))
360 * Type of the current tracing.
362 enum ftrace_tracing_type_t {
363 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
364 FTRACE_TYPE_RETURN, /* Hook the return of the function */
367 /* Current tracing type, default is FTRACE_TYPE_ENTER */
368 extern enum ftrace_tracing_type_t ftrace_tracing_type;
371 * The ftrace_ops must be a static and should also
372 * be read_mostly. These functions do modify read_mostly variables
373 * so use them sparely. Never free an ftrace_op or modify the
374 * next pointer after it has been registered. Even after unregistering
375 * it, the next pointer may still be used internally.
377 int register_ftrace_function(struct ftrace_ops *ops);
378 int unregister_ftrace_function(struct ftrace_ops *ops);
380 extern void ftrace_stub(unsigned long a0, unsigned long a1,
381 struct ftrace_ops *op, struct ftrace_regs *fregs);
384 int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs);
385 #else /* !CONFIG_FUNCTION_TRACER */
387 * (un)register_ftrace_function must be a macro since the ops parameter
388 * must not be evaluated.
390 #define register_ftrace_function(ops) ({ 0; })
391 #define unregister_ftrace_function(ops) ({ 0; })
392 static inline void ftrace_kill(void) { }
393 static inline void ftrace_free_init_mem(void) { }
394 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
395 static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
399 #endif /* CONFIG_FUNCTION_TRACER */
401 struct ftrace_func_entry {
402 struct hlist_node hlist;
404 unsigned long direct; /* for direct lookup only */
407 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
408 extern int ftrace_direct_func_count;
409 unsigned long ftrace_find_rec_direct(unsigned long ip);
410 int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr);
411 int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
413 int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr);
414 int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr);
416 void ftrace_stub_direct_tramp(void);
420 # define ftrace_direct_func_count 0
421 static inline unsigned long ftrace_find_rec_direct(unsigned long ip)
425 static inline int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
429 static inline int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
434 static inline int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
438 static inline int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr)
444 * This must be implemented by the architecture.
445 * It is the way the ftrace direct_ops helper, when called
446 * via ftrace (because there's other callbacks besides the
447 * direct call), can inform the architecture's trampoline that this
448 * routine has a direct caller, and what the caller is.
450 * For example, in x86, it returns the direct caller
451 * callback function via the regs->orig_ax parameter.
452 * Then in the ftrace trampoline, if this is set, it makes
453 * the return from the trampoline jump to the direct caller
454 * instead of going back to the function it just traced.
456 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs,
457 unsigned long addr) { }
458 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
460 #ifdef CONFIG_STACK_TRACER
462 extern int stack_tracer_enabled;
464 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer,
465 size_t *lenp, loff_t *ppos);
467 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
468 DECLARE_PER_CPU(int, disable_stack_tracer);
471 * stack_tracer_disable - temporarily disable the stack tracer
473 * There's a few locations (namely in RCU) where stack tracing
474 * cannot be executed. This function is used to disable stack
475 * tracing during those critical sections.
477 * This function must be called with preemption or interrupts
478 * disabled and stack_tracer_enable() must be called shortly after
479 * while preemption or interrupts are still disabled.
481 static inline void stack_tracer_disable(void)
483 /* Preemption or interrupts must be disabled */
484 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
485 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
486 this_cpu_inc(disable_stack_tracer);
490 * stack_tracer_enable - re-enable the stack tracer
492 * After stack_tracer_disable() is called, stack_tracer_enable()
493 * must be called shortly afterward.
495 static inline void stack_tracer_enable(void)
497 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
498 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
499 this_cpu_dec(disable_stack_tracer);
502 static inline void stack_tracer_disable(void) { }
503 static inline void stack_tracer_enable(void) { }
506 #ifdef CONFIG_DYNAMIC_FTRACE
508 void ftrace_arch_code_modify_prepare(void);
509 void ftrace_arch_code_modify_post_process(void);
511 enum ftrace_bug_type {
518 extern enum ftrace_bug_type ftrace_bug_type;
521 * Archs can set this to point to a variable that holds the value that was
522 * expected at the call site before calling ftrace_bug().
524 extern const void *ftrace_expected;
526 void ftrace_bug(int err, struct dyn_ftrace *rec);
530 extern int ftrace_text_reserved(const void *start, const void *end);
532 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
534 bool is_ftrace_trampoline(unsigned long addr);
537 * The dyn_ftrace record's flags field is split into two parts.
538 * the first part which is '0-FTRACE_REF_MAX' is a counter of
539 * the number of callbacks that have registered the function that
540 * the dyn_ftrace descriptor represents.
542 * The second part is a mask:
543 * ENABLED - the function is being traced
544 * REGS - the record wants the function to save regs
545 * REGS_EN - the function is set up to save regs.
546 * IPMODIFY - the record allows for the IP address to be changed.
547 * DISABLED - the record is not ready to be touched yet
548 * DIRECT - there is a direct function to call
549 * CALL_OPS - the record can use callsite-specific ops
550 * CALL_OPS_EN - the function is set up to use callsite-specific ops
551 * TOUCHED - A callback was added since boot up
553 * When a new ftrace_ops is registered and wants a function to save
554 * pt_regs, the rec->flags REGS is set. When the function has been
555 * set up to save regs, the REG_EN flag is set. Once a function
556 * starts saving regs it will do so until all ftrace_ops are removed
557 * from tracing that function.
560 FTRACE_FL_ENABLED = (1UL << 31),
561 FTRACE_FL_REGS = (1UL << 30),
562 FTRACE_FL_REGS_EN = (1UL << 29),
563 FTRACE_FL_TRAMP = (1UL << 28),
564 FTRACE_FL_TRAMP_EN = (1UL << 27),
565 FTRACE_FL_IPMODIFY = (1UL << 26),
566 FTRACE_FL_DISABLED = (1UL << 25),
567 FTRACE_FL_DIRECT = (1UL << 24),
568 FTRACE_FL_DIRECT_EN = (1UL << 23),
569 FTRACE_FL_CALL_OPS = (1UL << 22),
570 FTRACE_FL_CALL_OPS_EN = (1UL << 21),
571 FTRACE_FL_TOUCHED = (1UL << 20),
574 #define FTRACE_REF_MAX_SHIFT 20
575 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
577 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX)
580 unsigned long ip; /* address of mcount call-site */
582 struct dyn_arch_ftrace arch;
585 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
586 int remove, int reset);
587 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
588 unsigned int cnt, int remove, int reset);
589 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
591 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
593 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
594 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
595 void ftrace_free_filter(struct ftrace_ops *ops);
596 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
599 FTRACE_UPDATE_CALLS = (1 << 0),
600 FTRACE_DISABLE_CALLS = (1 << 1),
601 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
602 FTRACE_START_FUNC_RET = (1 << 3),
603 FTRACE_STOP_FUNC_RET = (1 << 4),
604 FTRACE_MAY_SLEEP = (1 << 5),
608 * The FTRACE_UPDATE_* enum is used to pass information back
609 * from the ftrace_update_record() and ftrace_test_record()
610 * functions. These are called by the code update routines
611 * to find out what is to be done for a given function.
613 * IGNORE - The function is already what we want it to be
614 * MAKE_CALL - Start tracing the function
615 * MODIFY_CALL - Stop saving regs for the function
616 * MAKE_NOP - Stop tracing the function
619 FTRACE_UPDATE_IGNORE,
620 FTRACE_UPDATE_MAKE_CALL,
621 FTRACE_UPDATE_MODIFY_CALL,
622 FTRACE_UPDATE_MAKE_NOP,
626 FTRACE_ITER_FILTER = (1 << 0),
627 FTRACE_ITER_NOTRACE = (1 << 1),
628 FTRACE_ITER_PRINTALL = (1 << 2),
629 FTRACE_ITER_DO_PROBES = (1 << 3),
630 FTRACE_ITER_PROBE = (1 << 4),
631 FTRACE_ITER_MOD = (1 << 5),
632 FTRACE_ITER_ENABLED = (1 << 6),
633 FTRACE_ITER_TOUCHED = (1 << 7),
636 void arch_ftrace_update_code(int command);
637 void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
638 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
639 void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
641 struct ftrace_rec_iter;
643 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
644 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
645 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
647 #define for_ftrace_rec_iter(iter) \
648 for (iter = ftrace_rec_iter_start(); \
650 iter = ftrace_rec_iter_next(iter))
653 int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
654 int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
655 void ftrace_run_stop_machine(int command);
656 unsigned long ftrace_location(unsigned long ip);
657 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
658 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
659 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
661 extern ftrace_func_t ftrace_trace_function;
663 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
664 struct inode *inode, struct file *file);
665 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
666 size_t cnt, loff_t *ppos);
667 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
668 size_t cnt, loff_t *ppos);
669 int ftrace_regex_release(struct inode *inode, struct file *file);
672 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
674 /* defined in arch */
675 extern int ftrace_ip_converted(unsigned long ip);
676 extern int ftrace_dyn_arch_init(void);
677 extern void ftrace_replace_code(int enable);
678 extern int ftrace_update_ftrace_func(ftrace_func_t func);
679 extern void ftrace_caller(void);
680 extern void ftrace_regs_caller(void);
681 extern void ftrace_call(void);
682 extern void ftrace_regs_call(void);
683 extern void mcount_call(void);
685 void ftrace_modify_all_code(int command);
688 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
691 #ifndef FTRACE_GRAPH_ADDR
692 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
695 #ifndef FTRACE_REGS_ADDR
696 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
697 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
699 # define FTRACE_REGS_ADDR FTRACE_ADDR
704 * If an arch would like functions that are only traced
705 * by the function graph tracer to jump directly to its own
706 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
707 * to be that address to jump to.
709 #ifndef FTRACE_GRAPH_TRAMP_ADDR
710 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
713 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
714 extern void ftrace_graph_caller(void);
715 extern int ftrace_enable_ftrace_graph_caller(void);
716 extern int ftrace_disable_ftrace_graph_caller(void);
718 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
719 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
723 * ftrace_make_nop - convert code into nop
724 * @mod: module structure if called by module load initialization
725 * @rec: the call site record (e.g. mcount/fentry)
726 * @addr: the address that the call site should be calling
728 * This is a very sensitive operation and great care needs
729 * to be taken by the arch. The operation should carefully
730 * read the location, check to see if what is read is indeed
731 * what we expect it to be, and then on success of the compare,
732 * it should write to the location.
734 * The code segment at @rec->ip should be a caller to @addr
738 * -EFAULT on error reading the location
739 * -EINVAL on a failed compare of the contents
740 * -EPERM on error writing to the location
741 * Any other value will be considered a failure.
743 extern int ftrace_make_nop(struct module *mod,
744 struct dyn_ftrace *rec, unsigned long addr);
747 * ftrace_need_init_nop - return whether nop call sites should be initialized
749 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't
750 * need to call ftrace_init_nop() if the code is built with that flag.
751 * Architectures where this is not always the case may define their own
755 * 0 if ftrace_init_nop() should be called
756 * Nonzero if ftrace_init_nop() should not be called
759 #ifndef ftrace_need_init_nop
760 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT))
764 * ftrace_init_nop - initialize a nop call site
765 * @mod: module structure if called by module load initialization
766 * @rec: the call site record (e.g. mcount/fentry)
768 * This is a very sensitive operation and great care needs
769 * to be taken by the arch. The operation should carefully
770 * read the location, check to see if what is read is indeed
771 * what we expect it to be, and then on success of the compare,
772 * it should write to the location.
774 * The code segment at @rec->ip should contain the contents created by
779 * -EFAULT on error reading the location
780 * -EINVAL on a failed compare of the contents
781 * -EPERM on error writing to the location
782 * Any other value will be considered a failure.
784 #ifndef ftrace_init_nop
785 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
787 return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
792 * ftrace_make_call - convert a nop call site into a call to addr
793 * @rec: the call site record (e.g. mcount/fentry)
794 * @addr: the address that the call site should call
796 * This is a very sensitive operation and great care needs
797 * to be taken by the arch. The operation should carefully
798 * read the location, check to see if what is read is indeed
799 * what we expect it to be, and then on success of the compare,
800 * it should write to the location.
802 * The code segment at @rec->ip should be a nop
806 * -EFAULT on error reading the location
807 * -EINVAL on a failed compare of the contents
808 * -EPERM on error writing to the location
809 * Any other value will be considered a failure.
811 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
813 #if defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) || \
814 defined(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS)
816 * ftrace_modify_call - convert from one addr to another (no nop)
817 * @rec: the call site record (e.g. mcount/fentry)
818 * @old_addr: the address expected to be currently called to
819 * @addr: the address to change to
821 * This is a very sensitive operation and great care needs
822 * to be taken by the arch. The operation should carefully
823 * read the location, check to see if what is read is indeed
824 * what we expect it to be, and then on success of the compare,
825 * it should write to the location.
827 * When using call ops, this is called when the associated ops change, even
828 * when (addr == old_addr).
830 * The code segment at @rec->ip should be a caller to @old_addr
834 * -EFAULT on error reading the location
835 * -EINVAL on a failed compare of the contents
836 * -EPERM on error writing to the location
837 * Any other value will be considered a failure.
839 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
842 /* Should never be called */
843 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
850 /* May be defined in arch */
851 extern int ftrace_arch_read_dyn_info(char *buf, int size);
853 extern int skip_trace(unsigned long ip);
854 extern void ftrace_module_init(struct module *mod);
855 extern void ftrace_module_enable(struct module *mod);
856 extern void ftrace_release_mod(struct module *mod);
858 extern void ftrace_disable_daemon(void);
859 extern void ftrace_enable_daemon(void);
860 #else /* CONFIG_DYNAMIC_FTRACE */
861 static inline int skip_trace(unsigned long ip) { return 0; }
862 static inline void ftrace_disable_daemon(void) { }
863 static inline void ftrace_enable_daemon(void) { }
864 static inline void ftrace_module_init(struct module *mod) { }
865 static inline void ftrace_module_enable(struct module *mod) { }
866 static inline void ftrace_release_mod(struct module *mod) { }
867 static inline int ftrace_text_reserved(const void *start, const void *end)
871 static inline unsigned long ftrace_location(unsigned long ip)
877 * Again users of functions that have ftrace_ops may not
878 * have them defined when ftrace is not enabled, but these
879 * functions may still be called. Use a macro instead of inline.
881 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
882 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
883 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
884 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; })
885 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
886 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
887 #define ftrace_free_filter(ops) do { } while (0)
888 #define ftrace_ops_set_global_filter(ops) do { } while (0)
890 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
891 size_t cnt, loff_t *ppos) { return -ENODEV; }
892 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
893 size_t cnt, loff_t *ppos) { return -ENODEV; }
895 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
897 static inline bool is_ftrace_trampoline(unsigned long addr)
901 #endif /* CONFIG_DYNAMIC_FTRACE */
903 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
904 #ifndef ftrace_graph_func
905 #define ftrace_graph_func ftrace_stub
906 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB
908 #define FTRACE_OPS_GRAPH_STUB 0
910 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
912 /* totally disable ftrace - can not re-enable after this */
913 void ftrace_kill(void);
915 static inline void tracer_disable(void)
917 #ifdef CONFIG_FUNCTION_TRACER
923 * Ftrace disable/restore without lock. Some synchronization mechanism
924 * must be used to prevent ftrace_enabled to be changed between
927 static inline int __ftrace_enabled_save(void)
929 #ifdef CONFIG_FUNCTION_TRACER
930 int saved_ftrace_enabled = ftrace_enabled;
932 return saved_ftrace_enabled;
938 static inline void __ftrace_enabled_restore(int enabled)
940 #ifdef CONFIG_FUNCTION_TRACER
941 ftrace_enabled = enabled;
945 /* All archs should have this, but we define it for consistency */
946 #ifndef ftrace_return_address0
947 # define ftrace_return_address0 __builtin_return_address(0)
950 /* Archs may use other ways for ADDR1 and beyond */
951 #ifndef ftrace_return_address
952 # ifdef CONFIG_FRAME_POINTER
953 # define ftrace_return_address(n) __builtin_return_address(n)
955 # define ftrace_return_address(n) 0UL
959 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
960 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
961 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
962 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
963 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
964 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
965 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
967 static __always_inline unsigned long get_lock_parent_ip(void)
969 unsigned long addr = CALLER_ADDR0;
971 if (!in_lock_functions(addr))
974 if (!in_lock_functions(addr))
979 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
980 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
981 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
984 * Use defines instead of static inlines because some arches will make code out
985 * of the CALLER_ADDR, when we really want these to be a real nop.
987 # define trace_preempt_on(a0, a1) do { } while (0)
988 # define trace_preempt_off(a0, a1) do { } while (0)
991 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
992 extern void ftrace_init(void);
993 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
994 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
996 #define FTRACE_CALLSITE_SECTION "__mcount_loc"
999 static inline void ftrace_init(void) { }
1003 * Structure that defines an entry function trace.
1004 * It's already packed but the attribute "packed" is needed
1005 * to remove extra padding at the end.
1007 struct ftrace_graph_ent {
1008 unsigned long func; /* Current function */
1013 * Structure that defines a return function trace.
1014 * It's already packed but the attribute "packed" is needed
1015 * to remove extra padding at the end.
1017 struct ftrace_graph_ret {
1018 unsigned long func; /* Current function */
1020 /* Number of functions that overran the depth limit for current task */
1021 unsigned int overrun;
1022 unsigned long long calltime;
1023 unsigned long long rettime;
1026 /* Type of the callback handlers for tracing function graph*/
1027 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
1028 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
1030 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
1032 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1035 trace_func_graph_ent_t entryfunc;
1036 trace_func_graph_ret_t retfunc;
1040 * Stack of return addresses for functions
1042 * Used in struct thread_info
1044 struct ftrace_ret_stack {
1047 unsigned long long calltime;
1048 #ifdef CONFIG_FUNCTION_PROFILER
1049 unsigned long long subtime;
1051 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
1054 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
1055 unsigned long *retp;
1060 * Primary handler of a function return.
1061 * It relays on ftrace_return_to_handler.
1062 * Defined in entry_32/64.S
1064 extern void return_to_handler(void);
1067 function_graph_enter(unsigned long ret, unsigned long func,
1068 unsigned long frame_pointer, unsigned long *retp);
1070 struct ftrace_ret_stack *
1071 ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
1073 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
1074 unsigned long ret, unsigned long *retp);
1077 * Sometimes we don't want to trace a function with the function
1078 * graph tracer but we want them to keep traced by the usual function
1079 * tracer if the function graph tracer is not configured.
1081 #define __notrace_funcgraph notrace
1083 #define FTRACE_RETFUNC_DEPTH 50
1084 #define FTRACE_RETSTACK_ALLOC_SIZE 32
1086 extern int register_ftrace_graph(struct fgraph_ops *ops);
1087 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
1090 * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
1092 * ftrace_graph_stop() is called when a severe error is detected in
1093 * the function graph tracing. This function is called by the critical
1094 * paths of function graph to keep those paths from doing any more harm.
1096 DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph);
1098 static inline bool ftrace_graph_is_dead(void)
1100 return static_branch_unlikely(&kill_ftrace_graph);
1103 extern void ftrace_graph_stop(void);
1105 /* The current handlers in use */
1106 extern trace_func_graph_ret_t ftrace_graph_return;
1107 extern trace_func_graph_ent_t ftrace_graph_entry;
1109 extern void ftrace_graph_init_task(struct task_struct *t);
1110 extern void ftrace_graph_exit_task(struct task_struct *t);
1111 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
1113 static inline void pause_graph_tracing(void)
1115 atomic_inc(¤t->tracing_graph_pause);
1118 static inline void unpause_graph_tracing(void)
1120 atomic_dec(¤t->tracing_graph_pause);
1122 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
1124 #define __notrace_funcgraph
1126 static inline void ftrace_graph_init_task(struct task_struct *t) { }
1127 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
1128 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
1130 /* Define as macros as fgraph_ops may not be defined */
1131 #define register_ftrace_graph(ops) ({ -1; })
1132 #define unregister_ftrace_graph(ops) do { } while (0)
1134 static inline unsigned long
1135 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
1136 unsigned long *retp)
1141 static inline void pause_graph_tracing(void) { }
1142 static inline void unpause_graph_tracing(void) { }
1143 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1145 #ifdef CONFIG_TRACING
1146 enum ftrace_dump_mode;
1148 extern enum ftrace_dump_mode ftrace_dump_on_oops;
1149 extern int tracepoint_printk;
1151 extern void disable_trace_on_warning(void);
1152 extern int __disable_trace_on_warning;
1154 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
1155 void *buffer, size_t *lenp, loff_t *ppos);
1157 #else /* CONFIG_TRACING */
1158 static inline void disable_trace_on_warning(void) { }
1159 #endif /* CONFIG_TRACING */
1161 #ifdef CONFIG_FTRACE_SYSCALLS
1163 unsigned long arch_syscall_addr(int nr);
1165 #endif /* CONFIG_FTRACE_SYSCALLS */
1167 #endif /* _LINUX_FTRACE_H */