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/kallsyms.h>
13 #include <linux/linkage.h>
14 #include <linux/bitops.h>
15 #include <linux/ptrace.h>
16 #include <linux/ktime.h>
17 #include <linux/sched.h>
18 #include <linux/types.h>
19 #include <linux/init.h>
22 #include <asm/ftrace.h>
25 * If the arch supports passing the variable contents of
26 * function_trace_op as the third parameter back from the
27 * mcount call, then the arch should define this as 1.
29 #ifndef ARCH_SUPPORTS_FTRACE_OPS
30 #define ARCH_SUPPORTS_FTRACE_OPS 0
34 extern void ftrace_boot_snapshot(void);
36 static inline void ftrace_boot_snapshot(void) { }
39 #ifdef CONFIG_FUNCTION_TRACER
43 * If the arch's mcount caller does not support all of ftrace's
44 * features, then it must call an indirect function that
45 * does. Or at least does enough to prevent any unwelcome side effects.
47 * Also define the function prototype that these architectures use
48 * to call the ftrace_ops_list_func().
50 #if !ARCH_SUPPORTS_FTRACE_OPS
51 # define FTRACE_FORCE_LIST_FUNC 1
52 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
54 # define FTRACE_FORCE_LIST_FUNC 0
55 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
56 struct ftrace_ops *op, struct ftrace_regs *fregs);
58 #endif /* CONFIG_FUNCTION_TRACER */
60 /* Main tracing buffer and events set up */
62 void trace_init(void);
63 void early_trace_init(void);
65 static inline void trace_init(void) { }
66 static inline void early_trace_init(void) { }
71 struct ftrace_direct_func;
73 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
74 defined(CONFIG_DYNAMIC_FTRACE)
76 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
77 unsigned long *off, char **modname, char *sym);
79 static inline const char *
80 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
81 unsigned long *off, char **modname, char *sym)
87 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
88 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
89 char *type, char *name,
90 char *module_name, int *exported);
92 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
93 char *type, char *name,
94 char *module_name, int *exported)
100 #ifdef CONFIG_FUNCTION_TRACER
102 extern int ftrace_enabled;
104 ftrace_enable_sysctl(struct ctl_table *table, int write,
105 void *buffer, size_t *lenp, loff_t *ppos);
107 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
112 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs)
115 * ftrace_instruction_pointer_set() is to be defined by the architecture
116 * if to allow setting of the instruction pointer from the ftrace_regs
117 * when HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports
118 * live kernel patching.
120 #define ftrace_instruction_pointer_set(fregs, ip) do { } while (0)
121 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
123 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
128 return arch_ftrace_get_regs(fregs);
131 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
132 struct ftrace_ops *op, struct ftrace_regs *fregs);
134 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
137 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
138 * set in the flags member.
139 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and
140 * IPMODIFY are a kind of attribute flags which can be set only before
141 * registering the ftrace_ops, and can not be modified while registered.
142 * Changing those attribute flags after registering ftrace_ops will
143 * cause unexpected results.
145 * ENABLED - set/unset when ftrace_ops is registered/unregistered
146 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
147 * allocated ftrace_ops which need special care
148 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
149 * and passed to the callback. If this flag is set, but the
150 * architecture does not support passing regs
151 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
152 * ftrace_ops will fail to register, unless the next flag
154 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
155 * handler can handle an arch that does not save regs
156 * (the handler tests if regs == NULL), then it can set
157 * this flag instead. It will not fail registering the ftrace_ops
158 * but, the regs field will be NULL if the arch does not support
159 * passing regs to the handler.
160 * Note, if this flag is set, the SAVE_REGS flag will automatically
161 * get set upon registering the ftrace_ops, if the arch supports it.
162 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure
163 * that the call back needs recursion protection. If it does
164 * not set this, then the ftrace infrastructure will assume
165 * that the callback can handle recursion on its own.
166 * STUB - The ftrace_ops is just a place holder.
167 * INITIALIZED - The ftrace_ops has already been initialized (first use time
168 * register_ftrace_function() is called, it will initialized the ops)
169 * DELETED - The ops are being deleted, do not let them be registered again.
170 * ADDING - The ops is in the process of being added.
171 * REMOVING - The ops is in the process of being removed.
172 * MODIFYING - The ops is in the process of changing its filter functions.
173 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
174 * The arch specific code sets this flag when it allocated a
175 * trampoline. This lets the arch know that it can update the
176 * trampoline in case the callback function changes.
177 * The ftrace_ops trampoline can be set by the ftrace users, and
178 * in such cases the arch must not modify it. Only the arch ftrace
179 * core code should set this flag.
180 * IPMODIFY - The ops can modify the IP register. This can only be set with
181 * SAVE_REGS. If another ops with this flag set is already registered
182 * for any of the functions that this ops will be registered for, then
183 * this ops will fail to register or set_filter_ip.
184 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
185 * RCU - Set when the ops can only be called when RCU is watching.
186 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
187 * PERMANENT - Set when the ops is permanent and should not be affected by
189 * DIRECT - Used by the direct ftrace_ops helper for direct functions
190 * (internal ftrace only, should not be used by others)
193 FTRACE_OPS_FL_ENABLED = BIT(0),
194 FTRACE_OPS_FL_DYNAMIC = BIT(1),
195 FTRACE_OPS_FL_SAVE_REGS = BIT(2),
196 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3),
197 FTRACE_OPS_FL_RECURSION = BIT(4),
198 FTRACE_OPS_FL_STUB = BIT(5),
199 FTRACE_OPS_FL_INITIALIZED = BIT(6),
200 FTRACE_OPS_FL_DELETED = BIT(7),
201 FTRACE_OPS_FL_ADDING = BIT(8),
202 FTRACE_OPS_FL_REMOVING = BIT(9),
203 FTRACE_OPS_FL_MODIFYING = BIT(10),
204 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11),
205 FTRACE_OPS_FL_IPMODIFY = BIT(12),
206 FTRACE_OPS_FL_PID = BIT(13),
207 FTRACE_OPS_FL_RCU = BIT(14),
208 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15),
209 FTRACE_OPS_FL_PERMANENT = BIT(16),
210 FTRACE_OPS_FL_DIRECT = BIT(17),
213 #ifdef CONFIG_DYNAMIC_FTRACE
214 /* The hash used to know what functions callbacks trace */
215 struct ftrace_ops_hash {
216 struct ftrace_hash __rcu *notrace_hash;
217 struct ftrace_hash __rcu *filter_hash;
218 struct mutex regex_lock;
221 void ftrace_free_init_mem(void);
222 void ftrace_free_mem(struct module *mod, void *start, void *end);
224 static inline void ftrace_free_init_mem(void)
226 ftrace_boot_snapshot();
228 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
232 * Note, ftrace_ops can be referenced outside of RCU protection, unless
233 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
234 * core data, the unregistering of it will perform a scheduling on all CPUs
235 * to make sure that there are no more users. Depending on the load of the
236 * system that may take a bit of time.
238 * Any private data added must also take care not to be freed and if private
239 * data is added to a ftrace_ops that is in core code, the user of the
240 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
244 struct ftrace_ops __rcu *next;
247 ftrace_func_t saved_func;
248 #ifdef CONFIG_DYNAMIC_FTRACE
249 struct ftrace_ops_hash local_hash;
250 struct ftrace_ops_hash *func_hash;
251 struct ftrace_ops_hash old_hash;
252 unsigned long trampoline;
253 unsigned long trampoline_size;
254 struct list_head list;
258 extern struct ftrace_ops __rcu *ftrace_ops_list;
259 extern struct ftrace_ops ftrace_list_end;
262 * Traverse the ftrace_ops_list, invoking all entries. The reason that we
263 * can use rcu_dereference_raw_check() is that elements removed from this list
264 * are simply leaked, so there is no need to interact with a grace-period
265 * mechanism. The rcu_dereference_raw_check() calls are needed to handle
266 * concurrent insertions into the ftrace_ops_list.
268 * Silly Alpha and silly pointer-speculation compiler optimizations!
270 #define do_for_each_ftrace_op(op, list) \
271 op = rcu_dereference_raw_check(list); \
275 * Optimized for just a single item in the list (as that is the normal case).
277 #define while_for_each_ftrace_op(op) \
278 while (likely(op = rcu_dereference_raw_check((op)->next)) && \
279 unlikely((op) != &ftrace_list_end))
282 * Type of the current tracing.
284 enum ftrace_tracing_type_t {
285 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
286 FTRACE_TYPE_RETURN, /* Hook the return of the function */
289 /* Current tracing type, default is FTRACE_TYPE_ENTER */
290 extern enum ftrace_tracing_type_t ftrace_tracing_type;
293 * The ftrace_ops must be a static and should also
294 * be read_mostly. These functions do modify read_mostly variables
295 * so use them sparely. Never free an ftrace_op or modify the
296 * next pointer after it has been registered. Even after unregistering
297 * it, the next pointer may still be used internally.
299 int register_ftrace_function(struct ftrace_ops *ops);
300 int unregister_ftrace_function(struct ftrace_ops *ops);
302 extern void ftrace_stub(unsigned long a0, unsigned long a1,
303 struct ftrace_ops *op, struct ftrace_regs *fregs);
305 #else /* !CONFIG_FUNCTION_TRACER */
307 * (un)register_ftrace_function must be a macro since the ops parameter
308 * must not be evaluated.
310 #define register_ftrace_function(ops) ({ 0; })
311 #define unregister_ftrace_function(ops) ({ 0; })
312 static inline void ftrace_kill(void) { }
313 static inline void ftrace_free_init_mem(void) { }
314 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
315 #endif /* CONFIG_FUNCTION_TRACER */
317 struct ftrace_func_entry {
318 struct hlist_node hlist;
320 unsigned long direct; /* for direct lookup only */
325 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
326 extern int ftrace_direct_func_count;
327 int register_ftrace_direct(unsigned long ip, unsigned long addr);
328 int unregister_ftrace_direct(unsigned long ip, unsigned long addr);
329 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr);
330 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr);
331 int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
332 struct dyn_ftrace *rec,
333 unsigned long old_addr,
334 unsigned long new_addr);
335 unsigned long ftrace_find_rec_direct(unsigned long ip);
336 int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
337 int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
338 int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
342 # define ftrace_direct_func_count 0
343 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
347 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
351 static inline int modify_ftrace_direct(unsigned long ip,
352 unsigned long old_addr, unsigned long new_addr)
356 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
360 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
361 struct dyn_ftrace *rec,
362 unsigned long old_addr,
363 unsigned long new_addr)
367 static inline unsigned long ftrace_find_rec_direct(unsigned long ip)
371 static inline int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
375 static inline int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
379 static inline int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
383 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
385 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
387 * This must be implemented by the architecture.
388 * It is the way the ftrace direct_ops helper, when called
389 * via ftrace (because there's other callbacks besides the
390 * direct call), can inform the architecture's trampoline that this
391 * routine has a direct caller, and what the caller is.
393 * For example, in x86, it returns the direct caller
394 * callback function via the regs->orig_ax parameter.
395 * Then in the ftrace trampoline, if this is set, it makes
396 * the return from the trampoline jump to the direct caller
397 * instead of going back to the function it just traced.
399 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs,
400 unsigned long addr) { }
401 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
403 #ifdef CONFIG_STACK_TRACER
405 extern int stack_tracer_enabled;
407 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer,
408 size_t *lenp, loff_t *ppos);
410 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
411 DECLARE_PER_CPU(int, disable_stack_tracer);
414 * stack_tracer_disable - temporarily disable the stack tracer
416 * There's a few locations (namely in RCU) where stack tracing
417 * cannot be executed. This function is used to disable stack
418 * tracing during those critical sections.
420 * This function must be called with preemption or interrupts
421 * disabled and stack_tracer_enable() must be called shortly after
422 * while preemption or interrupts are still disabled.
424 static inline void stack_tracer_disable(void)
426 /* Preemption or interrupts must be disabled */
427 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
428 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
429 this_cpu_inc(disable_stack_tracer);
433 * stack_tracer_enable - re-enable the stack tracer
435 * After stack_tracer_disable() is called, stack_tracer_enable()
436 * must be called shortly afterward.
438 static inline void stack_tracer_enable(void)
440 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
441 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
442 this_cpu_dec(disable_stack_tracer);
445 static inline void stack_tracer_disable(void) { }
446 static inline void stack_tracer_enable(void) { }
449 #ifdef CONFIG_DYNAMIC_FTRACE
451 int ftrace_arch_code_modify_prepare(void);
452 int ftrace_arch_code_modify_post_process(void);
454 enum ftrace_bug_type {
461 extern enum ftrace_bug_type ftrace_bug_type;
464 * Archs can set this to point to a variable that holds the value that was
465 * expected at the call site before calling ftrace_bug().
467 extern const void *ftrace_expected;
469 void ftrace_bug(int err, struct dyn_ftrace *rec);
473 extern int ftrace_text_reserved(const void *start, const void *end);
475 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
477 bool is_ftrace_trampoline(unsigned long addr);
480 * The dyn_ftrace record's flags field is split into two parts.
481 * the first part which is '0-FTRACE_REF_MAX' is a counter of
482 * the number of callbacks that have registered the function that
483 * the dyn_ftrace descriptor represents.
485 * The second part is a mask:
486 * ENABLED - the function is being traced
487 * REGS - the record wants the function to save regs
488 * REGS_EN - the function is set up to save regs.
489 * IPMODIFY - the record allows for the IP address to be changed.
490 * DISABLED - the record is not ready to be touched yet
491 * DIRECT - there is a direct function to call
493 * When a new ftrace_ops is registered and wants a function to save
494 * pt_regs, the rec->flags REGS is set. When the function has been
495 * set up to save regs, the REG_EN flag is set. Once a function
496 * starts saving regs it will do so until all ftrace_ops are removed
497 * from tracing that function.
500 FTRACE_FL_ENABLED = (1UL << 31),
501 FTRACE_FL_REGS = (1UL << 30),
502 FTRACE_FL_REGS_EN = (1UL << 29),
503 FTRACE_FL_TRAMP = (1UL << 28),
504 FTRACE_FL_TRAMP_EN = (1UL << 27),
505 FTRACE_FL_IPMODIFY = (1UL << 26),
506 FTRACE_FL_DISABLED = (1UL << 25),
507 FTRACE_FL_DIRECT = (1UL << 24),
508 FTRACE_FL_DIRECT_EN = (1UL << 23),
511 #define FTRACE_REF_MAX_SHIFT 23
512 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
514 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX)
517 unsigned long ip; /* address of mcount call-site */
519 struct dyn_arch_ftrace arch;
522 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
523 int remove, int reset);
524 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
525 unsigned int cnt, int remove, int reset);
526 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
528 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
530 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
531 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
532 void ftrace_free_filter(struct ftrace_ops *ops);
533 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
536 FTRACE_UPDATE_CALLS = (1 << 0),
537 FTRACE_DISABLE_CALLS = (1 << 1),
538 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
539 FTRACE_START_FUNC_RET = (1 << 3),
540 FTRACE_STOP_FUNC_RET = (1 << 4),
541 FTRACE_MAY_SLEEP = (1 << 5),
545 * The FTRACE_UPDATE_* enum is used to pass information back
546 * from the ftrace_update_record() and ftrace_test_record()
547 * functions. These are called by the code update routines
548 * to find out what is to be done for a given function.
550 * IGNORE - The function is already what we want it to be
551 * MAKE_CALL - Start tracing the function
552 * MODIFY_CALL - Stop saving regs for the function
553 * MAKE_NOP - Stop tracing the function
556 FTRACE_UPDATE_IGNORE,
557 FTRACE_UPDATE_MAKE_CALL,
558 FTRACE_UPDATE_MODIFY_CALL,
559 FTRACE_UPDATE_MAKE_NOP,
563 FTRACE_ITER_FILTER = (1 << 0),
564 FTRACE_ITER_NOTRACE = (1 << 1),
565 FTRACE_ITER_PRINTALL = (1 << 2),
566 FTRACE_ITER_DO_PROBES = (1 << 3),
567 FTRACE_ITER_PROBE = (1 << 4),
568 FTRACE_ITER_MOD = (1 << 5),
569 FTRACE_ITER_ENABLED = (1 << 6),
572 void arch_ftrace_update_code(int command);
573 void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
574 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
575 void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
577 struct ftrace_rec_iter;
579 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
580 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
581 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
583 #define for_ftrace_rec_iter(iter) \
584 for (iter = ftrace_rec_iter_start(); \
586 iter = ftrace_rec_iter_next(iter))
589 int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
590 int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
591 void ftrace_run_stop_machine(int command);
592 unsigned long ftrace_location(unsigned long ip);
593 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
594 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
595 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
597 extern ftrace_func_t ftrace_trace_function;
599 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
600 struct inode *inode, struct file *file);
601 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
602 size_t cnt, loff_t *ppos);
603 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
604 size_t cnt, loff_t *ppos);
605 int ftrace_regex_release(struct inode *inode, struct file *file);
608 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
610 /* defined in arch */
611 extern int ftrace_ip_converted(unsigned long ip);
612 extern int ftrace_dyn_arch_init(void);
613 extern void ftrace_replace_code(int enable);
614 extern int ftrace_update_ftrace_func(ftrace_func_t func);
615 extern void ftrace_caller(void);
616 extern void ftrace_regs_caller(void);
617 extern void ftrace_call(void);
618 extern void ftrace_regs_call(void);
619 extern void mcount_call(void);
621 void ftrace_modify_all_code(int command);
624 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
627 #ifndef FTRACE_GRAPH_ADDR
628 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
631 #ifndef FTRACE_REGS_ADDR
632 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
633 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
635 # define FTRACE_REGS_ADDR FTRACE_ADDR
640 * If an arch would like functions that are only traced
641 * by the function graph tracer to jump directly to its own
642 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
643 * to be that address to jump to.
645 #ifndef FTRACE_GRAPH_TRAMP_ADDR
646 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
649 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
650 extern void ftrace_graph_caller(void);
651 extern int ftrace_enable_ftrace_graph_caller(void);
652 extern int ftrace_disable_ftrace_graph_caller(void);
654 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
655 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
659 * ftrace_make_nop - convert code into nop
660 * @mod: module structure if called by module load initialization
661 * @rec: the call site record (e.g. mcount/fentry)
662 * @addr: the address that the call site should be calling
664 * This is a very sensitive operation and great care needs
665 * to be taken by the arch. The operation should carefully
666 * read the location, check to see if what is read is indeed
667 * what we expect it to be, and then on success of the compare,
668 * it should write to the location.
670 * The code segment at @rec->ip should be a caller to @addr
674 * -EFAULT on error reading the location
675 * -EINVAL on a failed compare of the contents
676 * -EPERM on error writing to the location
677 * Any other value will be considered a failure.
679 extern int ftrace_make_nop(struct module *mod,
680 struct dyn_ftrace *rec, unsigned long addr);
683 * ftrace_need_init_nop - return whether nop call sites should be initialized
685 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't
686 * need to call ftrace_init_nop() if the code is built with that flag.
687 * Architectures where this is not always the case may define their own
691 * 0 if ftrace_init_nop() should be called
692 * Nonzero if ftrace_init_nop() should not be called
695 #ifndef ftrace_need_init_nop
696 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT))
700 * ftrace_init_nop - initialize a nop call site
701 * @mod: module structure if called by module load initialization
702 * @rec: the call site record (e.g. mcount/fentry)
704 * This is a very sensitive operation and great care needs
705 * to be taken by the arch. The operation should carefully
706 * read the location, check to see if what is read is indeed
707 * what we expect it to be, and then on success of the compare,
708 * it should write to the location.
710 * The code segment at @rec->ip should contain the contents created by
715 * -EFAULT on error reading the location
716 * -EINVAL on a failed compare of the contents
717 * -EPERM on error writing to the location
718 * Any other value will be considered a failure.
720 #ifndef ftrace_init_nop
721 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
723 return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
728 * ftrace_make_call - convert a nop call site into a call to addr
729 * @rec: the call site record (e.g. mcount/fentry)
730 * @addr: the address that the call site should call
732 * This is a very sensitive operation and great care needs
733 * to be taken by the arch. The operation should carefully
734 * read the location, check to see if what is read is indeed
735 * what we expect it to be, and then on success of the compare,
736 * it should write to the location.
738 * The code segment at @rec->ip should be a nop
742 * -EFAULT on error reading the location
743 * -EINVAL on a failed compare of the contents
744 * -EPERM on error writing to the location
745 * Any other value will be considered a failure.
747 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
749 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
751 * ftrace_modify_call - convert from one addr to another (no nop)
752 * @rec: the call site record (e.g. mcount/fentry)
753 * @old_addr: the address expected to be currently called to
754 * @addr: the address to change to
756 * This is a very sensitive operation and great care needs
757 * to be taken by the arch. The operation should carefully
758 * read the location, check to see if what is read is indeed
759 * what we expect it to be, and then on success of the compare,
760 * it should write to the location.
762 * The code segment at @rec->ip should be a caller to @old_addr
766 * -EFAULT on error reading the location
767 * -EINVAL on a failed compare of the contents
768 * -EPERM on error writing to the location
769 * Any other value will be considered a failure.
771 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
774 /* Should never be called */
775 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
782 /* May be defined in arch */
783 extern int ftrace_arch_read_dyn_info(char *buf, int size);
785 extern int skip_trace(unsigned long ip);
786 extern void ftrace_module_init(struct module *mod);
787 extern void ftrace_module_enable(struct module *mod);
788 extern void ftrace_release_mod(struct module *mod);
790 extern void ftrace_disable_daemon(void);
791 extern void ftrace_enable_daemon(void);
792 #else /* CONFIG_DYNAMIC_FTRACE */
793 static inline int skip_trace(unsigned long ip) { return 0; }
794 static inline void ftrace_disable_daemon(void) { }
795 static inline void ftrace_enable_daemon(void) { }
796 static inline void ftrace_module_init(struct module *mod) { }
797 static inline void ftrace_module_enable(struct module *mod) { }
798 static inline void ftrace_release_mod(struct module *mod) { }
799 static inline int ftrace_text_reserved(const void *start, const void *end)
803 static inline unsigned long ftrace_location(unsigned long ip)
809 * Again users of functions that have ftrace_ops may not
810 * have them defined when ftrace is not enabled, but these
811 * functions may still be called. Use a macro instead of inline.
813 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
814 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
815 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
816 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; })
817 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
818 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
819 #define ftrace_free_filter(ops) do { } while (0)
820 #define ftrace_ops_set_global_filter(ops) do { } while (0)
822 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
823 size_t cnt, loff_t *ppos) { return -ENODEV; }
824 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
825 size_t cnt, loff_t *ppos) { return -ENODEV; }
827 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
829 static inline bool is_ftrace_trampoline(unsigned long addr)
833 #endif /* CONFIG_DYNAMIC_FTRACE */
835 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
836 #ifndef ftrace_graph_func
837 #define ftrace_graph_func ftrace_stub
838 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB
840 #define FTRACE_OPS_GRAPH_STUB 0
842 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
844 /* totally disable ftrace - can not re-enable after this */
845 void ftrace_kill(void);
847 static inline void tracer_disable(void)
849 #ifdef CONFIG_FUNCTION_TRACER
855 * Ftrace disable/restore without lock. Some synchronization mechanism
856 * must be used to prevent ftrace_enabled to be changed between
859 static inline int __ftrace_enabled_save(void)
861 #ifdef CONFIG_FUNCTION_TRACER
862 int saved_ftrace_enabled = ftrace_enabled;
864 return saved_ftrace_enabled;
870 static inline void __ftrace_enabled_restore(int enabled)
872 #ifdef CONFIG_FUNCTION_TRACER
873 ftrace_enabled = enabled;
877 /* All archs should have this, but we define it for consistency */
878 #ifndef ftrace_return_address0
879 # define ftrace_return_address0 __builtin_return_address(0)
882 /* Archs may use other ways for ADDR1 and beyond */
883 #ifndef ftrace_return_address
884 # ifdef CONFIG_FRAME_POINTER
885 # define ftrace_return_address(n) __builtin_return_address(n)
887 # define ftrace_return_address(n) 0UL
891 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
892 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
893 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
894 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
895 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
896 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
897 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
899 static inline unsigned long get_lock_parent_ip(void)
901 unsigned long addr = CALLER_ADDR0;
903 if (!in_lock_functions(addr))
906 if (!in_lock_functions(addr))
911 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
912 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
913 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
916 * Use defines instead of static inlines because some arches will make code out
917 * of the CALLER_ADDR, when we really want these to be a real nop.
919 # define trace_preempt_on(a0, a1) do { } while (0)
920 # define trace_preempt_off(a0, a1) do { } while (0)
923 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
924 extern void ftrace_init(void);
925 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
926 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
928 #define FTRACE_CALLSITE_SECTION "__mcount_loc"
931 static inline void ftrace_init(void) { }
935 * Structure that defines an entry function trace.
936 * It's already packed but the attribute "packed" is needed
937 * to remove extra padding at the end.
939 struct ftrace_graph_ent {
940 unsigned long func; /* Current function */
945 * Structure that defines a return function trace.
946 * It's already packed but the attribute "packed" is needed
947 * to remove extra padding at the end.
949 struct ftrace_graph_ret {
950 unsigned long func; /* Current function */
952 /* Number of functions that overran the depth limit for current task */
953 unsigned int overrun;
954 unsigned long long calltime;
955 unsigned long long rettime;
958 /* Type of the callback handlers for tracing function graph*/
959 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
960 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
962 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
964 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
967 trace_func_graph_ent_t entryfunc;
968 trace_func_graph_ret_t retfunc;
972 * Stack of return addresses for functions
974 * Used in struct thread_info
976 struct ftrace_ret_stack {
979 unsigned long long calltime;
980 #ifdef CONFIG_FUNCTION_PROFILER
981 unsigned long long subtime;
983 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
986 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
992 * Primary handler of a function return.
993 * It relays on ftrace_return_to_handler.
994 * Defined in entry_32/64.S
996 extern void return_to_handler(void);
999 function_graph_enter(unsigned long ret, unsigned long func,
1000 unsigned long frame_pointer, unsigned long *retp);
1002 struct ftrace_ret_stack *
1003 ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
1005 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
1006 unsigned long ret, unsigned long *retp);
1009 * Sometimes we don't want to trace a function with the function
1010 * graph tracer but we want them to keep traced by the usual function
1011 * tracer if the function graph tracer is not configured.
1013 #define __notrace_funcgraph notrace
1015 #define FTRACE_RETFUNC_DEPTH 50
1016 #define FTRACE_RETSTACK_ALLOC_SIZE 32
1018 extern int register_ftrace_graph(struct fgraph_ops *ops);
1019 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
1021 extern bool ftrace_graph_is_dead(void);
1022 extern void ftrace_graph_stop(void);
1024 /* The current handlers in use */
1025 extern trace_func_graph_ret_t ftrace_graph_return;
1026 extern trace_func_graph_ent_t ftrace_graph_entry;
1028 extern void ftrace_graph_init_task(struct task_struct *t);
1029 extern void ftrace_graph_exit_task(struct task_struct *t);
1030 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
1032 static inline void pause_graph_tracing(void)
1034 atomic_inc(¤t->tracing_graph_pause);
1037 static inline void unpause_graph_tracing(void)
1039 atomic_dec(¤t->tracing_graph_pause);
1041 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
1043 #define __notrace_funcgraph
1045 static inline void ftrace_graph_init_task(struct task_struct *t) { }
1046 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
1047 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
1049 /* Define as macros as fgraph_ops may not be defined */
1050 #define register_ftrace_graph(ops) ({ -1; })
1051 #define unregister_ftrace_graph(ops) do { } while (0)
1053 static inline unsigned long
1054 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
1055 unsigned long *retp)
1060 static inline void pause_graph_tracing(void) { }
1061 static inline void unpause_graph_tracing(void) { }
1062 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1064 #ifdef CONFIG_TRACING
1066 /* flags for current->trace */
1068 TSK_TRACE_FL_TRACE_BIT = 0,
1069 TSK_TRACE_FL_GRAPH_BIT = 1,
1072 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
1073 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
1076 static inline void set_tsk_trace_trace(struct task_struct *tsk)
1078 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
1081 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
1083 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
1086 static inline int test_tsk_trace_trace(struct task_struct *tsk)
1088 return tsk->trace & TSK_TRACE_FL_TRACE;
1091 static inline void set_tsk_trace_graph(struct task_struct *tsk)
1093 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
1096 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
1098 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
1101 static inline int test_tsk_trace_graph(struct task_struct *tsk)
1103 return tsk->trace & TSK_TRACE_FL_GRAPH;
1106 enum ftrace_dump_mode;
1108 extern enum ftrace_dump_mode ftrace_dump_on_oops;
1109 extern int tracepoint_printk;
1111 extern void disable_trace_on_warning(void);
1112 extern int __disable_trace_on_warning;
1114 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
1115 void *buffer, size_t *lenp, loff_t *ppos);
1117 #else /* CONFIG_TRACING */
1118 static inline void disable_trace_on_warning(void) { }
1119 #endif /* CONFIG_TRACING */
1121 #ifdef CONFIG_FTRACE_SYSCALLS
1123 unsigned long arch_syscall_addr(int nr);
1125 #endif /* CONFIG_FTRACE_SYSCALLS */
1127 #endif /* _LINUX_FTRACE_H */