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) { }
43 #ifdef CONFIG_FUNCTION_TRACER
45 * If the arch's mcount caller does not support all of ftrace's
46 * features, then it must call an indirect function that
47 * does. Or at least does enough to prevent any unwelcome side effects.
49 * Also define the function prototype that these architectures use
50 * to call the ftrace_ops_list_func().
52 #if !ARCH_SUPPORTS_FTRACE_OPS
53 # define FTRACE_FORCE_LIST_FUNC 1
54 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
56 # define FTRACE_FORCE_LIST_FUNC 0
57 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
58 struct ftrace_ops *op, struct ftrace_regs *fregs);
60 #endif /* CONFIG_FUNCTION_TRACER */
62 /* Main tracing buffer and events set up */
64 void trace_init(void);
65 void early_trace_init(void);
67 static inline void trace_init(void) { }
68 static inline void early_trace_init(void) { }
73 struct ftrace_direct_func;
75 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
76 defined(CONFIG_DYNAMIC_FTRACE)
78 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
79 unsigned long *off, char **modname, char *sym);
81 static inline const char *
82 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
83 unsigned long *off, char **modname, char *sym)
89 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
90 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
91 char *type, char *name,
92 char *module_name, int *exported);
94 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
95 char *type, char *name,
96 char *module_name, int *exported)
102 #ifdef CONFIG_FUNCTION_TRACER
104 extern int ftrace_enabled;
106 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
111 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs)
114 * ftrace_regs_set_instruction_pointer() is to be defined by the architecture
115 * if to allow setting of the instruction pointer from the ftrace_regs when
116 * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching.
118 #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0)
119 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
121 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
126 return arch_ftrace_get_regs(fregs);
130 * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs.
131 * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs.
133 static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs)
135 if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS))
138 return ftrace_get_regs(fregs) != NULL;
141 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
142 #define ftrace_regs_get_instruction_pointer(fregs) \
143 instruction_pointer(ftrace_get_regs(fregs))
144 #define ftrace_regs_get_argument(fregs, n) \
145 regs_get_kernel_argument(ftrace_get_regs(fregs), n)
146 #define ftrace_regs_get_stack_pointer(fregs) \
147 kernel_stack_pointer(ftrace_get_regs(fregs))
148 #define ftrace_regs_return_value(fregs) \
149 regs_return_value(ftrace_get_regs(fregs))
150 #define ftrace_regs_set_return_value(fregs, ret) \
151 regs_set_return_value(ftrace_get_regs(fregs), ret)
152 #define ftrace_override_function_with_return(fregs) \
153 override_function_with_return(ftrace_get_regs(fregs))
154 #define ftrace_regs_query_register_offset(name) \
155 regs_query_register_offset(name)
158 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
159 struct ftrace_ops *op, struct ftrace_regs *fregs);
161 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
164 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
165 * set in the flags member.
166 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and
167 * IPMODIFY are a kind of attribute flags which can be set only before
168 * registering the ftrace_ops, and can not be modified while registered.
169 * Changing those attribute flags after registering ftrace_ops will
170 * cause unexpected results.
172 * ENABLED - set/unset when ftrace_ops is registered/unregistered
173 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
174 * allocated ftrace_ops which need special care
175 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
176 * and passed to the callback. If this flag is set, but the
177 * architecture does not support passing regs
178 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
179 * ftrace_ops will fail to register, unless the next flag
181 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
182 * handler can handle an arch that does not save regs
183 * (the handler tests if regs == NULL), then it can set
184 * this flag instead. It will not fail registering the ftrace_ops
185 * but, the regs field will be NULL if the arch does not support
186 * passing regs to the handler.
187 * Note, if this flag is set, the SAVE_REGS flag will automatically
188 * get set upon registering the ftrace_ops, if the arch supports it.
189 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure
190 * that the call back needs recursion protection. If it does
191 * not set this, then the ftrace infrastructure will assume
192 * that the callback can handle recursion on its own.
193 * STUB - The ftrace_ops is just a place holder.
194 * INITIALIZED - The ftrace_ops has already been initialized (first use time
195 * register_ftrace_function() is called, it will initialized the ops)
196 * DELETED - The ops are being deleted, do not let them be registered again.
197 * ADDING - The ops is in the process of being added.
198 * REMOVING - The ops is in the process of being removed.
199 * MODIFYING - The ops is in the process of changing its filter functions.
200 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
201 * The arch specific code sets this flag when it allocated a
202 * trampoline. This lets the arch know that it can update the
203 * trampoline in case the callback function changes.
204 * The ftrace_ops trampoline can be set by the ftrace users, and
205 * in such cases the arch must not modify it. Only the arch ftrace
206 * core code should set this flag.
207 * IPMODIFY - The ops can modify the IP register. This can only be set with
208 * SAVE_REGS. If another ops with this flag set is already registered
209 * for any of the functions that this ops will be registered for, then
210 * this ops will fail to register or set_filter_ip.
211 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
212 * RCU - Set when the ops can only be called when RCU is watching.
213 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
214 * PERMANENT - Set when the ops is permanent and should not be affected by
216 * DIRECT - Used by the direct ftrace_ops helper for direct functions
217 * (internal ftrace only, should not be used by others)
220 FTRACE_OPS_FL_ENABLED = BIT(0),
221 FTRACE_OPS_FL_DYNAMIC = BIT(1),
222 FTRACE_OPS_FL_SAVE_REGS = BIT(2),
223 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3),
224 FTRACE_OPS_FL_RECURSION = BIT(4),
225 FTRACE_OPS_FL_STUB = BIT(5),
226 FTRACE_OPS_FL_INITIALIZED = BIT(6),
227 FTRACE_OPS_FL_DELETED = BIT(7),
228 FTRACE_OPS_FL_ADDING = BIT(8),
229 FTRACE_OPS_FL_REMOVING = BIT(9),
230 FTRACE_OPS_FL_MODIFYING = BIT(10),
231 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11),
232 FTRACE_OPS_FL_IPMODIFY = BIT(12),
233 FTRACE_OPS_FL_PID = BIT(13),
234 FTRACE_OPS_FL_RCU = BIT(14),
235 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15),
236 FTRACE_OPS_FL_PERMANENT = BIT(16),
237 FTRACE_OPS_FL_DIRECT = BIT(17),
241 * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes
242 * to a ftrace_ops. Note, the requests may fail.
244 * ENABLE_SHARE_IPMODIFY_SELF - enable a DIRECT ops to work on the same
245 * function as an ops with IPMODIFY. Called
246 * when the DIRECT ops is being registered.
247 * This is called with both direct_mutex and
248 * ftrace_lock are locked.
250 * ENABLE_SHARE_IPMODIFY_PEER - enable a DIRECT ops to work on the same
251 * function as an ops with IPMODIFY. Called
252 * when the other ops (the one with IPMODIFY)
253 * is being registered.
254 * This is called with direct_mutex locked.
256 * DISABLE_SHARE_IPMODIFY_PEER - disable a DIRECT ops to work on the same
257 * function as an ops with IPMODIFY. Called
258 * when the other ops (the one with IPMODIFY)
259 * is being unregistered.
260 * This is called with direct_mutex locked.
262 enum ftrace_ops_cmd {
263 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF,
264 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER,
265 FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER,
269 * For most ftrace_ops_cmd,
272 * Negative on failure. The return value is dependent on the
275 typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd cmd);
277 #ifdef CONFIG_DYNAMIC_FTRACE
278 /* The hash used to know what functions callbacks trace */
279 struct ftrace_ops_hash {
280 struct ftrace_hash __rcu *notrace_hash;
281 struct ftrace_hash __rcu *filter_hash;
282 struct mutex regex_lock;
285 void ftrace_free_init_mem(void);
286 void ftrace_free_mem(struct module *mod, void *start, void *end);
288 static inline void ftrace_free_init_mem(void)
290 ftrace_boot_snapshot();
292 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
296 * Note, ftrace_ops can be referenced outside of RCU protection, unless
297 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
298 * core data, the unregistering of it will perform a scheduling on all CPUs
299 * to make sure that there are no more users. Depending on the load of the
300 * system that may take a bit of time.
302 * Any private data added must also take care not to be freed and if private
303 * data is added to a ftrace_ops that is in core code, the user of the
304 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
308 struct ftrace_ops __rcu *next;
311 ftrace_func_t saved_func;
312 #ifdef CONFIG_DYNAMIC_FTRACE
313 struct ftrace_ops_hash local_hash;
314 struct ftrace_ops_hash *func_hash;
315 struct ftrace_ops_hash old_hash;
316 unsigned long trampoline;
317 unsigned long trampoline_size;
318 struct list_head list;
319 ftrace_ops_func_t ops_func;
323 extern struct ftrace_ops __rcu *ftrace_ops_list;
324 extern struct ftrace_ops ftrace_list_end;
327 * Traverse the ftrace_ops_list, invoking all entries. The reason that we
328 * can use rcu_dereference_raw_check() is that elements removed from this list
329 * are simply leaked, so there is no need to interact with a grace-period
330 * mechanism. The rcu_dereference_raw_check() calls are needed to handle
331 * concurrent insertions into the ftrace_ops_list.
333 * Silly Alpha and silly pointer-speculation compiler optimizations!
335 #define do_for_each_ftrace_op(op, list) \
336 op = rcu_dereference_raw_check(list); \
340 * Optimized for just a single item in the list (as that is the normal case).
342 #define while_for_each_ftrace_op(op) \
343 while (likely(op = rcu_dereference_raw_check((op)->next)) && \
344 unlikely((op) != &ftrace_list_end))
347 * Type of the current tracing.
349 enum ftrace_tracing_type_t {
350 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
351 FTRACE_TYPE_RETURN, /* Hook the return of the function */
354 /* Current tracing type, default is FTRACE_TYPE_ENTER */
355 extern enum ftrace_tracing_type_t ftrace_tracing_type;
358 * The ftrace_ops must be a static and should also
359 * be read_mostly. These functions do modify read_mostly variables
360 * so use them sparely. Never free an ftrace_op or modify the
361 * next pointer after it has been registered. Even after unregistering
362 * it, the next pointer may still be used internally.
364 int register_ftrace_function(struct ftrace_ops *ops);
365 int unregister_ftrace_function(struct ftrace_ops *ops);
367 extern void ftrace_stub(unsigned long a0, unsigned long a1,
368 struct ftrace_ops *op, struct ftrace_regs *fregs);
371 int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs);
372 #else /* !CONFIG_FUNCTION_TRACER */
374 * (un)register_ftrace_function must be a macro since the ops parameter
375 * must not be evaluated.
377 #define register_ftrace_function(ops) ({ 0; })
378 #define unregister_ftrace_function(ops) ({ 0; })
379 static inline void ftrace_kill(void) { }
380 static inline void ftrace_free_init_mem(void) { }
381 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
382 static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
386 #endif /* CONFIG_FUNCTION_TRACER */
388 struct ftrace_func_entry {
389 struct hlist_node hlist;
391 unsigned long direct; /* for direct lookup only */
396 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
397 extern int ftrace_direct_func_count;
398 int register_ftrace_direct(unsigned long ip, unsigned long addr);
399 int unregister_ftrace_direct(unsigned long ip, unsigned long addr);
400 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr);
401 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr);
402 int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
403 struct dyn_ftrace *rec,
404 unsigned long old_addr,
405 unsigned long new_addr);
406 unsigned long ftrace_find_rec_direct(unsigned long ip);
407 int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
408 int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
409 int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
410 int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr);
414 # define ftrace_direct_func_count 0
415 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
419 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
423 static inline int modify_ftrace_direct(unsigned long ip,
424 unsigned long old_addr, unsigned long new_addr)
428 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
432 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
433 struct dyn_ftrace *rec,
434 unsigned long old_addr,
435 unsigned long new_addr)
439 static inline unsigned long ftrace_find_rec_direct(unsigned long ip)
443 static inline int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
447 static inline int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
451 static inline int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
455 static inline int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr)
461 * This must be implemented by the architecture.
462 * It is the way the ftrace direct_ops helper, when called
463 * via ftrace (because there's other callbacks besides the
464 * direct call), can inform the architecture's trampoline that this
465 * routine has a direct caller, and what the caller is.
467 * For example, in x86, it returns the direct caller
468 * callback function via the regs->orig_ax parameter.
469 * Then in the ftrace trampoline, if this is set, it makes
470 * the return from the trampoline jump to the direct caller
471 * instead of going back to the function it just traced.
473 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs,
474 unsigned long addr) { }
475 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
477 #ifdef CONFIG_STACK_TRACER
479 extern int stack_tracer_enabled;
481 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer,
482 size_t *lenp, loff_t *ppos);
484 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
485 DECLARE_PER_CPU(int, disable_stack_tracer);
488 * stack_tracer_disable - temporarily disable the stack tracer
490 * There's a few locations (namely in RCU) where stack tracing
491 * cannot be executed. This function is used to disable stack
492 * tracing during those critical sections.
494 * This function must be called with preemption or interrupts
495 * disabled and stack_tracer_enable() must be called shortly after
496 * while preemption or interrupts are still disabled.
498 static inline void stack_tracer_disable(void)
500 /* Preemption or interrupts must be disabled */
501 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
502 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
503 this_cpu_inc(disable_stack_tracer);
507 * stack_tracer_enable - re-enable the stack tracer
509 * After stack_tracer_disable() is called, stack_tracer_enable()
510 * must be called shortly afterward.
512 static inline void stack_tracer_enable(void)
514 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
515 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
516 this_cpu_dec(disable_stack_tracer);
519 static inline void stack_tracer_disable(void) { }
520 static inline void stack_tracer_enable(void) { }
523 #ifdef CONFIG_DYNAMIC_FTRACE
525 void ftrace_arch_code_modify_prepare(void);
526 void ftrace_arch_code_modify_post_process(void);
528 enum ftrace_bug_type {
535 extern enum ftrace_bug_type ftrace_bug_type;
538 * Archs can set this to point to a variable that holds the value that was
539 * expected at the call site before calling ftrace_bug().
541 extern const void *ftrace_expected;
543 void ftrace_bug(int err, struct dyn_ftrace *rec);
547 extern int ftrace_text_reserved(const void *start, const void *end);
549 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
551 bool is_ftrace_trampoline(unsigned long addr);
554 * The dyn_ftrace record's flags field is split into two parts.
555 * the first part which is '0-FTRACE_REF_MAX' is a counter of
556 * the number of callbacks that have registered the function that
557 * the dyn_ftrace descriptor represents.
559 * The second part is a mask:
560 * ENABLED - the function is being traced
561 * REGS - the record wants the function to save regs
562 * REGS_EN - the function is set up to save regs.
563 * IPMODIFY - the record allows for the IP address to be changed.
564 * DISABLED - the record is not ready to be touched yet
565 * DIRECT - there is a direct function to call
567 * When a new ftrace_ops is registered and wants a function to save
568 * pt_regs, the rec->flags REGS is set. When the function has been
569 * set up to save regs, the REG_EN flag is set. Once a function
570 * starts saving regs it will do so until all ftrace_ops are removed
571 * from tracing that function.
574 FTRACE_FL_ENABLED = (1UL << 31),
575 FTRACE_FL_REGS = (1UL << 30),
576 FTRACE_FL_REGS_EN = (1UL << 29),
577 FTRACE_FL_TRAMP = (1UL << 28),
578 FTRACE_FL_TRAMP_EN = (1UL << 27),
579 FTRACE_FL_IPMODIFY = (1UL << 26),
580 FTRACE_FL_DISABLED = (1UL << 25),
581 FTRACE_FL_DIRECT = (1UL << 24),
582 FTRACE_FL_DIRECT_EN = (1UL << 23),
585 #define FTRACE_REF_MAX_SHIFT 23
586 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
588 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX)
591 unsigned long ip; /* address of mcount call-site */
593 struct dyn_arch_ftrace arch;
596 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
597 int remove, int reset);
598 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
599 unsigned int cnt, int remove, int reset);
600 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
602 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
604 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
605 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
606 void ftrace_free_filter(struct ftrace_ops *ops);
607 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
610 FTRACE_UPDATE_CALLS = (1 << 0),
611 FTRACE_DISABLE_CALLS = (1 << 1),
612 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
613 FTRACE_START_FUNC_RET = (1 << 3),
614 FTRACE_STOP_FUNC_RET = (1 << 4),
615 FTRACE_MAY_SLEEP = (1 << 5),
619 * The FTRACE_UPDATE_* enum is used to pass information back
620 * from the ftrace_update_record() and ftrace_test_record()
621 * functions. These are called by the code update routines
622 * to find out what is to be done for a given function.
624 * IGNORE - The function is already what we want it to be
625 * MAKE_CALL - Start tracing the function
626 * MODIFY_CALL - Stop saving regs for the function
627 * MAKE_NOP - Stop tracing the function
630 FTRACE_UPDATE_IGNORE,
631 FTRACE_UPDATE_MAKE_CALL,
632 FTRACE_UPDATE_MODIFY_CALL,
633 FTRACE_UPDATE_MAKE_NOP,
637 FTRACE_ITER_FILTER = (1 << 0),
638 FTRACE_ITER_NOTRACE = (1 << 1),
639 FTRACE_ITER_PRINTALL = (1 << 2),
640 FTRACE_ITER_DO_PROBES = (1 << 3),
641 FTRACE_ITER_PROBE = (1 << 4),
642 FTRACE_ITER_MOD = (1 << 5),
643 FTRACE_ITER_ENABLED = (1 << 6),
646 void arch_ftrace_update_code(int command);
647 void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
648 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
649 void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
651 struct ftrace_rec_iter;
653 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
654 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
655 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
657 #define for_ftrace_rec_iter(iter) \
658 for (iter = ftrace_rec_iter_start(); \
660 iter = ftrace_rec_iter_next(iter))
663 int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
664 int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
665 void ftrace_run_stop_machine(int command);
666 unsigned long ftrace_location(unsigned long ip);
667 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
668 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
669 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
671 extern ftrace_func_t ftrace_trace_function;
673 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
674 struct inode *inode, struct file *file);
675 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
676 size_t cnt, loff_t *ppos);
677 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
678 size_t cnt, loff_t *ppos);
679 int ftrace_regex_release(struct inode *inode, struct file *file);
682 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
684 /* defined in arch */
685 extern int ftrace_ip_converted(unsigned long ip);
686 extern int ftrace_dyn_arch_init(void);
687 extern void ftrace_replace_code(int enable);
688 extern int ftrace_update_ftrace_func(ftrace_func_t func);
689 extern void ftrace_caller(void);
690 extern void ftrace_regs_caller(void);
691 extern void ftrace_call(void);
692 extern void ftrace_regs_call(void);
693 extern void mcount_call(void);
695 void ftrace_modify_all_code(int command);
698 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
701 #ifndef FTRACE_GRAPH_ADDR
702 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
705 #ifndef FTRACE_REGS_ADDR
706 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
707 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
709 # define FTRACE_REGS_ADDR FTRACE_ADDR
714 * If an arch would like functions that are only traced
715 * by the function graph tracer to jump directly to its own
716 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
717 * to be that address to jump to.
719 #ifndef FTRACE_GRAPH_TRAMP_ADDR
720 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
723 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
724 extern void ftrace_graph_caller(void);
725 extern int ftrace_enable_ftrace_graph_caller(void);
726 extern int ftrace_disable_ftrace_graph_caller(void);
728 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
729 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
733 * ftrace_make_nop - convert code into nop
734 * @mod: module structure if called by module load initialization
735 * @rec: the call site record (e.g. mcount/fentry)
736 * @addr: the address that the call site should be calling
738 * This is a very sensitive operation and great care needs
739 * to be taken by the arch. The operation should carefully
740 * read the location, check to see if what is read is indeed
741 * what we expect it to be, and then on success of the compare,
742 * it should write to the location.
744 * The code segment at @rec->ip should be a caller to @addr
748 * -EFAULT on error reading the location
749 * -EINVAL on a failed compare of the contents
750 * -EPERM on error writing to the location
751 * Any other value will be considered a failure.
753 extern int ftrace_make_nop(struct module *mod,
754 struct dyn_ftrace *rec, unsigned long addr);
757 * ftrace_need_init_nop - return whether nop call sites should be initialized
759 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't
760 * need to call ftrace_init_nop() if the code is built with that flag.
761 * Architectures where this is not always the case may define their own
765 * 0 if ftrace_init_nop() should be called
766 * Nonzero if ftrace_init_nop() should not be called
769 #ifndef ftrace_need_init_nop
770 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT))
774 * ftrace_init_nop - initialize a nop call site
775 * @mod: module structure if called by module load initialization
776 * @rec: the call site record (e.g. mcount/fentry)
778 * This is a very sensitive operation and great care needs
779 * to be taken by the arch. The operation should carefully
780 * read the location, check to see if what is read is indeed
781 * what we expect it to be, and then on success of the compare,
782 * it should write to the location.
784 * The code segment at @rec->ip should contain the contents created by
789 * -EFAULT on error reading the location
790 * -EINVAL on a failed compare of the contents
791 * -EPERM on error writing to the location
792 * Any other value will be considered a failure.
794 #ifndef ftrace_init_nop
795 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
797 return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
802 * ftrace_make_call - convert a nop call site into a call to addr
803 * @rec: the call site record (e.g. mcount/fentry)
804 * @addr: the address that the call site should call
806 * This is a very sensitive operation and great care needs
807 * to be taken by the arch. The operation should carefully
808 * read the location, check to see if what is read is indeed
809 * what we expect it to be, and then on success of the compare,
810 * it should write to the location.
812 * The code segment at @rec->ip should be a nop
816 * -EFAULT on error reading the location
817 * -EINVAL on a failed compare of the contents
818 * -EPERM on error writing to the location
819 * Any other value will be considered a failure.
821 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
823 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
825 * ftrace_modify_call - convert from one addr to another (no nop)
826 * @rec: the call site record (e.g. mcount/fentry)
827 * @old_addr: the address expected to be currently called to
828 * @addr: the address to change to
830 * This is a very sensitive operation and great care needs
831 * to be taken by the arch. The operation should carefully
832 * read the location, check to see if what is read is indeed
833 * what we expect it to be, and then on success of the compare,
834 * it should write to the location.
836 * The code segment at @rec->ip should be a caller to @old_addr
840 * -EFAULT on error reading the location
841 * -EINVAL on a failed compare of the contents
842 * -EPERM on error writing to the location
843 * Any other value will be considered a failure.
845 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
848 /* Should never be called */
849 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
856 /* May be defined in arch */
857 extern int ftrace_arch_read_dyn_info(char *buf, int size);
859 extern int skip_trace(unsigned long ip);
860 extern void ftrace_module_init(struct module *mod);
861 extern void ftrace_module_enable(struct module *mod);
862 extern void ftrace_release_mod(struct module *mod);
864 extern void ftrace_disable_daemon(void);
865 extern void ftrace_enable_daemon(void);
866 #else /* CONFIG_DYNAMIC_FTRACE */
867 static inline int skip_trace(unsigned long ip) { return 0; }
868 static inline void ftrace_disable_daemon(void) { }
869 static inline void ftrace_enable_daemon(void) { }
870 static inline void ftrace_module_init(struct module *mod) { }
871 static inline void ftrace_module_enable(struct module *mod) { }
872 static inline void ftrace_release_mod(struct module *mod) { }
873 static inline int ftrace_text_reserved(const void *start, const void *end)
877 static inline unsigned long ftrace_location(unsigned long ip)
883 * Again users of functions that have ftrace_ops may not
884 * have them defined when ftrace is not enabled, but these
885 * functions may still be called. Use a macro instead of inline.
887 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
888 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
889 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
890 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; })
891 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
892 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
893 #define ftrace_free_filter(ops) do { } while (0)
894 #define ftrace_ops_set_global_filter(ops) do { } while (0)
896 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
897 size_t cnt, loff_t *ppos) { return -ENODEV; }
898 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
899 size_t cnt, loff_t *ppos) { return -ENODEV; }
901 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
903 static inline bool is_ftrace_trampoline(unsigned long addr)
907 #endif /* CONFIG_DYNAMIC_FTRACE */
909 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
910 #ifndef ftrace_graph_func
911 #define ftrace_graph_func ftrace_stub
912 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB
914 #define FTRACE_OPS_GRAPH_STUB 0
916 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
918 /* totally disable ftrace - can not re-enable after this */
919 void ftrace_kill(void);
921 static inline void tracer_disable(void)
923 #ifdef CONFIG_FUNCTION_TRACER
929 * Ftrace disable/restore without lock. Some synchronization mechanism
930 * must be used to prevent ftrace_enabled to be changed between
933 static inline int __ftrace_enabled_save(void)
935 #ifdef CONFIG_FUNCTION_TRACER
936 int saved_ftrace_enabled = ftrace_enabled;
938 return saved_ftrace_enabled;
944 static inline void __ftrace_enabled_restore(int enabled)
946 #ifdef CONFIG_FUNCTION_TRACER
947 ftrace_enabled = enabled;
951 /* All archs should have this, but we define it for consistency */
952 #ifndef ftrace_return_address0
953 # define ftrace_return_address0 __builtin_return_address(0)
956 /* Archs may use other ways for ADDR1 and beyond */
957 #ifndef ftrace_return_address
958 # ifdef CONFIG_FRAME_POINTER
959 # define ftrace_return_address(n) __builtin_return_address(n)
961 # define ftrace_return_address(n) 0UL
965 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
966 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
967 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
968 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
969 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
970 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
971 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
973 static inline unsigned long get_lock_parent_ip(void)
975 unsigned long addr = CALLER_ADDR0;
977 if (!in_lock_functions(addr))
980 if (!in_lock_functions(addr))
985 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
986 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
987 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
990 * Use defines instead of static inlines because some arches will make code out
991 * of the CALLER_ADDR, when we really want these to be a real nop.
993 # define trace_preempt_on(a0, a1) do { } while (0)
994 # define trace_preempt_off(a0, a1) do { } while (0)
997 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
998 extern void ftrace_init(void);
999 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
1000 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
1002 #define FTRACE_CALLSITE_SECTION "__mcount_loc"
1005 static inline void ftrace_init(void) { }
1009 * Structure that defines an entry function trace.
1010 * It's already packed but the attribute "packed" is needed
1011 * to remove extra padding at the end.
1013 struct ftrace_graph_ent {
1014 unsigned long func; /* Current function */
1019 * Structure that defines a return function trace.
1020 * It's already packed but the attribute "packed" is needed
1021 * to remove extra padding at the end.
1023 struct ftrace_graph_ret {
1024 unsigned long func; /* Current function */
1026 /* Number of functions that overran the depth limit for current task */
1027 unsigned int overrun;
1028 unsigned long long calltime;
1029 unsigned long long rettime;
1032 /* Type of the callback handlers for tracing function graph*/
1033 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
1034 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
1036 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
1038 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1041 trace_func_graph_ent_t entryfunc;
1042 trace_func_graph_ret_t retfunc;
1046 * Stack of return addresses for functions
1048 * Used in struct thread_info
1050 struct ftrace_ret_stack {
1053 unsigned long long calltime;
1054 #ifdef CONFIG_FUNCTION_PROFILER
1055 unsigned long long subtime;
1057 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
1060 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
1061 unsigned long *retp;
1066 * Primary handler of a function return.
1067 * It relays on ftrace_return_to_handler.
1068 * Defined in entry_32/64.S
1070 extern void return_to_handler(void);
1073 function_graph_enter(unsigned long ret, unsigned long func,
1074 unsigned long frame_pointer, unsigned long *retp);
1076 struct ftrace_ret_stack *
1077 ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
1079 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
1080 unsigned long ret, unsigned long *retp);
1083 * Sometimes we don't want to trace a function with the function
1084 * graph tracer but we want them to keep traced by the usual function
1085 * tracer if the function graph tracer is not configured.
1087 #define __notrace_funcgraph notrace
1089 #define FTRACE_RETFUNC_DEPTH 50
1090 #define FTRACE_RETSTACK_ALLOC_SIZE 32
1092 extern int register_ftrace_graph(struct fgraph_ops *ops);
1093 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
1096 * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
1098 * ftrace_graph_stop() is called when a severe error is detected in
1099 * the function graph tracing. This function is called by the critical
1100 * paths of function graph to keep those paths from doing any more harm.
1102 DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph);
1104 static inline bool ftrace_graph_is_dead(void)
1106 return static_branch_unlikely(&kill_ftrace_graph);
1109 extern void ftrace_graph_stop(void);
1111 /* The current handlers in use */
1112 extern trace_func_graph_ret_t ftrace_graph_return;
1113 extern trace_func_graph_ent_t ftrace_graph_entry;
1115 extern void ftrace_graph_init_task(struct task_struct *t);
1116 extern void ftrace_graph_exit_task(struct task_struct *t);
1117 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
1119 static inline void pause_graph_tracing(void)
1121 atomic_inc(¤t->tracing_graph_pause);
1124 static inline void unpause_graph_tracing(void)
1126 atomic_dec(¤t->tracing_graph_pause);
1128 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
1130 #define __notrace_funcgraph
1132 static inline void ftrace_graph_init_task(struct task_struct *t) { }
1133 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
1134 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
1136 /* Define as macros as fgraph_ops may not be defined */
1137 #define register_ftrace_graph(ops) ({ -1; })
1138 #define unregister_ftrace_graph(ops) do { } while (0)
1140 static inline unsigned long
1141 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
1142 unsigned long *retp)
1147 static inline void pause_graph_tracing(void) { }
1148 static inline void unpause_graph_tracing(void) { }
1149 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1151 #ifdef CONFIG_TRACING
1152 enum ftrace_dump_mode;
1154 extern enum ftrace_dump_mode ftrace_dump_on_oops;
1155 extern int tracepoint_printk;
1157 extern void disable_trace_on_warning(void);
1158 extern int __disable_trace_on_warning;
1160 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
1161 void *buffer, size_t *lenp, loff_t *ppos);
1163 #else /* CONFIG_TRACING */
1164 static inline void disable_trace_on_warning(void) { }
1165 #endif /* CONFIG_TRACING */
1167 #ifdef CONFIG_FTRACE_SYSCALLS
1169 unsigned long arch_syscall_addr(int nr);
1171 #endif /* CONFIG_FTRACE_SYSCALLS */
1173 #endif /* _LINUX_FTRACE_H */