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 * If the arch's mcount caller does not support all of ftrace's
35 * features, then it must call an indirect function that
36 * does. Or at least does enough to prevent any unwelcome side effects.
38 #if !ARCH_SUPPORTS_FTRACE_OPS
39 # define FTRACE_FORCE_LIST_FUNC 1
41 # define FTRACE_FORCE_LIST_FUNC 0
44 /* Main tracing buffer and events set up */
46 void trace_init(void);
47 void early_trace_init(void);
49 static inline void trace_init(void) { }
50 static inline void early_trace_init(void) { }
55 struct ftrace_direct_func
;
57 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
58 defined(CONFIG_DYNAMIC_FTRACE)
60 ftrace_mod_address_lookup(unsigned long addr
, unsigned long *size
,
61 unsigned long *off
, char **modname
, char *sym
);
63 static inline const char *
64 ftrace_mod_address_lookup(unsigned long addr
, unsigned long *size
,
65 unsigned long *off
, char **modname
, char *sym
)
71 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
72 int ftrace_mod_get_kallsym(unsigned int symnum
, unsigned long *value
,
73 char *type
, char *name
,
74 char *module_name
, int *exported
);
76 static inline int ftrace_mod_get_kallsym(unsigned int symnum
, unsigned long *value
,
77 char *type
, char *name
,
78 char *module_name
, int *exported
)
84 #ifdef CONFIG_FUNCTION_TRACER
86 extern int ftrace_enabled
;
88 ftrace_enable_sysctl(struct ctl_table
*table
, int write
,
89 void *buffer
, size_t *lenp
, loff_t
*ppos
);
93 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
98 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs)
101 * ftrace_instruction_pointer_set() is to be defined by the architecture
102 * if to allow setting of the instruction pointer from the ftrace_regs
103 * when HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports
104 * live kernel patching.
106 #define ftrace_instruction_pointer_set(fregs, ip) do { } while (0)
107 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
109 static __always_inline
struct pt_regs
*ftrace_get_regs(struct ftrace_regs
*fregs
)
114 return arch_ftrace_get_regs(fregs
);
117 typedef void (*ftrace_func_t
)(unsigned long ip
, unsigned long parent_ip
,
118 struct ftrace_ops
*op
, struct ftrace_regs
*fregs
);
120 ftrace_func_t
ftrace_ops_get_func(struct ftrace_ops
*ops
);
123 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
124 * set in the flags member.
125 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and
126 * IPMODIFY are a kind of attribute flags which can be set only before
127 * registering the ftrace_ops, and can not be modified while registered.
128 * Changing those attribute flags after registering ftrace_ops will
129 * cause unexpected results.
131 * ENABLED - set/unset when ftrace_ops is registered/unregistered
132 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
133 * allocated ftrace_ops which need special care
134 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
135 * and passed to the callback. If this flag is set, but the
136 * architecture does not support passing regs
137 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
138 * ftrace_ops will fail to register, unless the next flag
140 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
141 * handler can handle an arch that does not save regs
142 * (the handler tests if regs == NULL), then it can set
143 * this flag instead. It will not fail registering the ftrace_ops
144 * but, the regs field will be NULL if the arch does not support
145 * passing regs to the handler.
146 * Note, if this flag is set, the SAVE_REGS flag will automatically
147 * get set upon registering the ftrace_ops, if the arch supports it.
148 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure
149 * that the call back needs recursion protection. If it does
150 * not set this, then the ftrace infrastructure will assume
151 * that the callback can handle recursion on its own.
152 * STUB - The ftrace_ops is just a place holder.
153 * INITIALIZED - The ftrace_ops has already been initialized (first use time
154 * register_ftrace_function() is called, it will initialized the ops)
155 * DELETED - The ops are being deleted, do not let them be registered again.
156 * ADDING - The ops is in the process of being added.
157 * REMOVING - The ops is in the process of being removed.
158 * MODIFYING - The ops is in the process of changing its filter functions.
159 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
160 * The arch specific code sets this flag when it allocated a
161 * trampoline. This lets the arch know that it can update the
162 * trampoline in case the callback function changes.
163 * The ftrace_ops trampoline can be set by the ftrace users, and
164 * in such cases the arch must not modify it. Only the arch ftrace
165 * core code should set this flag.
166 * IPMODIFY - The ops can modify the IP register. This can only be set with
167 * SAVE_REGS. If another ops with this flag set is already registered
168 * for any of the functions that this ops will be registered for, then
169 * this ops will fail to register or set_filter_ip.
170 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
171 * RCU - Set when the ops can only be called when RCU is watching.
172 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
173 * PERMANENT - Set when the ops is permanent and should not be affected by
175 * DIRECT - Used by the direct ftrace_ops helper for direct functions
176 * (internal ftrace only, should not be used by others)
179 FTRACE_OPS_FL_ENABLED
= BIT(0),
180 FTRACE_OPS_FL_DYNAMIC
= BIT(1),
181 FTRACE_OPS_FL_SAVE_REGS
= BIT(2),
182 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED
= BIT(3),
183 FTRACE_OPS_FL_RECURSION
= BIT(4),
184 FTRACE_OPS_FL_STUB
= BIT(5),
185 FTRACE_OPS_FL_INITIALIZED
= BIT(6),
186 FTRACE_OPS_FL_DELETED
= BIT(7),
187 FTRACE_OPS_FL_ADDING
= BIT(8),
188 FTRACE_OPS_FL_REMOVING
= BIT(9),
189 FTRACE_OPS_FL_MODIFYING
= BIT(10),
190 FTRACE_OPS_FL_ALLOC_TRAMP
= BIT(11),
191 FTRACE_OPS_FL_IPMODIFY
= BIT(12),
192 FTRACE_OPS_FL_PID
= BIT(13),
193 FTRACE_OPS_FL_RCU
= BIT(14),
194 FTRACE_OPS_FL_TRACE_ARRAY
= BIT(15),
195 FTRACE_OPS_FL_PERMANENT
= BIT(16),
196 FTRACE_OPS_FL_DIRECT
= BIT(17),
199 #ifdef CONFIG_DYNAMIC_FTRACE
200 /* The hash used to know what functions callbacks trace */
201 struct ftrace_ops_hash
{
202 struct ftrace_hash __rcu
*notrace_hash
;
203 struct ftrace_hash __rcu
*filter_hash
;
204 struct mutex regex_lock
;
207 void ftrace_free_init_mem(void);
208 void ftrace_free_mem(struct module
*mod
, void *start
, void *end
);
210 static inline void ftrace_free_init_mem(void) { }
211 static inline void ftrace_free_mem(struct module
*mod
, void *start
, void *end
) { }
215 * Note, ftrace_ops can be referenced outside of RCU protection, unless
216 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
217 * core data, the unregistering of it will perform a scheduling on all CPUs
218 * to make sure that there are no more users. Depending on the load of the
219 * system that may take a bit of time.
221 * Any private data added must also take care not to be freed and if private
222 * data is added to a ftrace_ops that is in core code, the user of the
223 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
227 struct ftrace_ops __rcu
*next
;
230 ftrace_func_t saved_func
;
231 #ifdef CONFIG_DYNAMIC_FTRACE
232 struct ftrace_ops_hash local_hash
;
233 struct ftrace_ops_hash
*func_hash
;
234 struct ftrace_ops_hash old_hash
;
235 unsigned long trampoline
;
236 unsigned long trampoline_size
;
237 struct list_head list
;
241 extern struct ftrace_ops __rcu
*ftrace_ops_list
;
242 extern struct ftrace_ops ftrace_list_end
;
245 * Traverse the ftrace_ops_list, invoking all entries. The reason that we
246 * can use rcu_dereference_raw_check() is that elements removed from this list
247 * are simply leaked, so there is no need to interact with a grace-period
248 * mechanism. The rcu_dereference_raw_check() calls are needed to handle
249 * concurrent insertions into the ftrace_ops_list.
251 * Silly Alpha and silly pointer-speculation compiler optimizations!
253 #define do_for_each_ftrace_op(op, list) \
254 op = rcu_dereference_raw_check(list); \
258 * Optimized for just a single item in the list (as that is the normal case).
260 #define while_for_each_ftrace_op(op) \
261 while (likely(op = rcu_dereference_raw_check((op)->next)) && \
262 unlikely((op) != &ftrace_list_end))
265 * Type of the current tracing.
267 enum ftrace_tracing_type_t
{
268 FTRACE_TYPE_ENTER
= 0, /* Hook the call of the function */
269 FTRACE_TYPE_RETURN
, /* Hook the return of the function */
272 /* Current tracing type, default is FTRACE_TYPE_ENTER */
273 extern enum ftrace_tracing_type_t ftrace_tracing_type
;
276 * The ftrace_ops must be a static and should also
277 * be read_mostly. These functions do modify read_mostly variables
278 * so use them sparely. Never free an ftrace_op or modify the
279 * next pointer after it has been registered. Even after unregistering
280 * it, the next pointer may still be used internally.
282 int register_ftrace_function(struct ftrace_ops
*ops
);
283 int unregister_ftrace_function(struct ftrace_ops
*ops
);
285 extern void ftrace_stub(unsigned long a0
, unsigned long a1
,
286 struct ftrace_ops
*op
, struct ftrace_regs
*fregs
);
288 #else /* !CONFIG_FUNCTION_TRACER */
290 * (un)register_ftrace_function must be a macro since the ops parameter
291 * must not be evaluated.
293 #define register_ftrace_function(ops) ({ 0; })
294 #define unregister_ftrace_function(ops) ({ 0; })
295 static inline void ftrace_kill(void) { }
296 static inline void ftrace_free_init_mem(void) { }
297 static inline void ftrace_free_mem(struct module
*mod
, void *start
, void *end
) { }
298 #endif /* CONFIG_FUNCTION_TRACER */
300 struct ftrace_func_entry
{
301 struct hlist_node hlist
;
303 unsigned long direct
; /* for direct lookup only */
308 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
309 extern int ftrace_direct_func_count
;
310 int register_ftrace_direct(unsigned long ip
, unsigned long addr
);
311 int unregister_ftrace_direct(unsigned long ip
, unsigned long addr
);
312 int modify_ftrace_direct(unsigned long ip
, unsigned long old_addr
, unsigned long new_addr
);
313 struct ftrace_direct_func
*ftrace_find_direct_func(unsigned long addr
);
314 int ftrace_modify_direct_caller(struct ftrace_func_entry
*entry
,
315 struct dyn_ftrace
*rec
,
316 unsigned long old_addr
,
317 unsigned long new_addr
);
318 unsigned long ftrace_find_rec_direct(unsigned long ip
);
320 # define ftrace_direct_func_count 0
321 static inline int register_ftrace_direct(unsigned long ip
, unsigned long addr
)
325 static inline int unregister_ftrace_direct(unsigned long ip
, unsigned long addr
)
329 static inline int modify_ftrace_direct(unsigned long ip
,
330 unsigned long old_addr
, unsigned long new_addr
)
334 static inline struct ftrace_direct_func
*ftrace_find_direct_func(unsigned long addr
)
338 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry
*entry
,
339 struct dyn_ftrace
*rec
,
340 unsigned long old_addr
,
341 unsigned long new_addr
)
345 static inline unsigned long ftrace_find_rec_direct(unsigned long ip
)
349 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
351 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
353 * This must be implemented by the architecture.
354 * It is the way the ftrace direct_ops helper, when called
355 * via ftrace (because there's other callbacks besides the
356 * direct call), can inform the architecture's trampoline that this
357 * routine has a direct caller, and what the caller is.
359 * For example, in x86, it returns the direct caller
360 * callback function via the regs->orig_ax parameter.
361 * Then in the ftrace trampoline, if this is set, it makes
362 * the return from the trampoline jump to the direct caller
363 * instead of going back to the function it just traced.
365 static inline void arch_ftrace_set_direct_caller(struct pt_regs
*regs
,
366 unsigned long addr
) { }
367 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
369 #ifdef CONFIG_STACK_TRACER
371 extern int stack_tracer_enabled
;
373 int stack_trace_sysctl(struct ctl_table
*table
, int write
, void *buffer
,
374 size_t *lenp
, loff_t
*ppos
);
376 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
377 DECLARE_PER_CPU(int, disable_stack_tracer
);
380 * stack_tracer_disable - temporarily disable the stack tracer
382 * There's a few locations (namely in RCU) where stack tracing
383 * cannot be executed. This function is used to disable stack
384 * tracing during those critical sections.
386 * This function must be called with preemption or interrupts
387 * disabled and stack_tracer_enable() must be called shortly after
388 * while preemption or interrupts are still disabled.
390 static inline void stack_tracer_disable(void)
392 /* Preemption or interrupts must be disabled */
393 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT
))
394 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
395 this_cpu_inc(disable_stack_tracer
);
399 * stack_tracer_enable - re-enable the stack tracer
401 * After stack_tracer_disable() is called, stack_tracer_enable()
402 * must be called shortly afterward.
404 static inline void stack_tracer_enable(void)
406 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT
))
407 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
408 this_cpu_dec(disable_stack_tracer
);
411 static inline void stack_tracer_disable(void) { }
412 static inline void stack_tracer_enable(void) { }
415 #ifdef CONFIG_DYNAMIC_FTRACE
417 int ftrace_arch_code_modify_prepare(void);
418 int ftrace_arch_code_modify_post_process(void);
420 enum ftrace_bug_type
{
427 extern enum ftrace_bug_type ftrace_bug_type
;
430 * Archs can set this to point to a variable that holds the value that was
431 * expected at the call site before calling ftrace_bug().
433 extern const void *ftrace_expected
;
435 void ftrace_bug(int err
, struct dyn_ftrace
*rec
);
439 extern int ftrace_text_reserved(const void *start
, const void *end
);
441 struct ftrace_ops
*ftrace_ops_trampoline(unsigned long addr
);
443 bool is_ftrace_trampoline(unsigned long addr
);
446 * The dyn_ftrace record's flags field is split into two parts.
447 * the first part which is '0-FTRACE_REF_MAX' is a counter of
448 * the number of callbacks that have registered the function that
449 * the dyn_ftrace descriptor represents.
451 * The second part is a mask:
452 * ENABLED - the function is being traced
453 * REGS - the record wants the function to save regs
454 * REGS_EN - the function is set up to save regs.
455 * IPMODIFY - the record allows for the IP address to be changed.
456 * DISABLED - the record is not ready to be touched yet
457 * DIRECT - there is a direct function to call
459 * When a new ftrace_ops is registered and wants a function to save
460 * pt_regs, the rec->flags REGS is set. When the function has been
461 * set up to save regs, the REG_EN flag is set. Once a function
462 * starts saving regs it will do so until all ftrace_ops are removed
463 * from tracing that function.
466 FTRACE_FL_ENABLED
= (1UL << 31),
467 FTRACE_FL_REGS
= (1UL << 30),
468 FTRACE_FL_REGS_EN
= (1UL << 29),
469 FTRACE_FL_TRAMP
= (1UL << 28),
470 FTRACE_FL_TRAMP_EN
= (1UL << 27),
471 FTRACE_FL_IPMODIFY
= (1UL << 26),
472 FTRACE_FL_DISABLED
= (1UL << 25),
473 FTRACE_FL_DIRECT
= (1UL << 24),
474 FTRACE_FL_DIRECT_EN
= (1UL << 23),
477 #define FTRACE_REF_MAX_SHIFT 23
478 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
480 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX)
483 unsigned long ip
; /* address of mcount call-site */
485 struct dyn_arch_ftrace arch
;
488 int ftrace_set_filter_ip(struct ftrace_ops
*ops
, unsigned long ip
,
489 int remove
, int reset
);
490 int ftrace_set_filter(struct ftrace_ops
*ops
, unsigned char *buf
,
492 int ftrace_set_notrace(struct ftrace_ops
*ops
, unsigned char *buf
,
494 void ftrace_set_global_filter(unsigned char *buf
, int len
, int reset
);
495 void ftrace_set_global_notrace(unsigned char *buf
, int len
, int reset
);
496 void ftrace_free_filter(struct ftrace_ops
*ops
);
497 void ftrace_ops_set_global_filter(struct ftrace_ops
*ops
);
500 FTRACE_UPDATE_CALLS
= (1 << 0),
501 FTRACE_DISABLE_CALLS
= (1 << 1),
502 FTRACE_UPDATE_TRACE_FUNC
= (1 << 2),
503 FTRACE_START_FUNC_RET
= (1 << 3),
504 FTRACE_STOP_FUNC_RET
= (1 << 4),
505 FTRACE_MAY_SLEEP
= (1 << 5),
509 * The FTRACE_UPDATE_* enum is used to pass information back
510 * from the ftrace_update_record() and ftrace_test_record()
511 * functions. These are called by the code update routines
512 * to find out what is to be done for a given function.
514 * IGNORE - The function is already what we want it to be
515 * MAKE_CALL - Start tracing the function
516 * MODIFY_CALL - Stop saving regs for the function
517 * MAKE_NOP - Stop tracing the function
520 FTRACE_UPDATE_IGNORE
,
521 FTRACE_UPDATE_MAKE_CALL
,
522 FTRACE_UPDATE_MODIFY_CALL
,
523 FTRACE_UPDATE_MAKE_NOP
,
527 FTRACE_ITER_FILTER
= (1 << 0),
528 FTRACE_ITER_NOTRACE
= (1 << 1),
529 FTRACE_ITER_PRINTALL
= (1 << 2),
530 FTRACE_ITER_DO_PROBES
= (1 << 3),
531 FTRACE_ITER_PROBE
= (1 << 4),
532 FTRACE_ITER_MOD
= (1 << 5),
533 FTRACE_ITER_ENABLED
= (1 << 6),
536 void arch_ftrace_update_code(int command
);
537 void arch_ftrace_update_trampoline(struct ftrace_ops
*ops
);
538 void *arch_ftrace_trampoline_func(struct ftrace_ops
*ops
, struct dyn_ftrace
*rec
);
539 void arch_ftrace_trampoline_free(struct ftrace_ops
*ops
);
541 struct ftrace_rec_iter
;
543 struct ftrace_rec_iter
*ftrace_rec_iter_start(void);
544 struct ftrace_rec_iter
*ftrace_rec_iter_next(struct ftrace_rec_iter
*iter
);
545 struct dyn_ftrace
*ftrace_rec_iter_record(struct ftrace_rec_iter
*iter
);
547 #define for_ftrace_rec_iter(iter) \
548 for (iter = ftrace_rec_iter_start(); \
550 iter = ftrace_rec_iter_next(iter))
553 int ftrace_update_record(struct dyn_ftrace
*rec
, bool enable
);
554 int ftrace_test_record(struct dyn_ftrace
*rec
, bool enable
);
555 void ftrace_run_stop_machine(int command
);
556 unsigned long ftrace_location(unsigned long ip
);
557 unsigned long ftrace_location_range(unsigned long start
, unsigned long end
);
558 unsigned long ftrace_get_addr_new(struct dyn_ftrace
*rec
);
559 unsigned long ftrace_get_addr_curr(struct dyn_ftrace
*rec
);
561 extern ftrace_func_t ftrace_trace_function
;
563 int ftrace_regex_open(struct ftrace_ops
*ops
, int flag
,
564 struct inode
*inode
, struct file
*file
);
565 ssize_t
ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
566 size_t cnt
, loff_t
*ppos
);
567 ssize_t
ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
568 size_t cnt
, loff_t
*ppos
);
569 int ftrace_regex_release(struct inode
*inode
, struct file
*file
);
572 ftrace_set_early_filter(struct ftrace_ops
*ops
, char *buf
, int enable
);
574 /* defined in arch */
575 extern int ftrace_ip_converted(unsigned long ip
);
576 extern int ftrace_dyn_arch_init(void);
577 extern void ftrace_replace_code(int enable
);
578 extern int ftrace_update_ftrace_func(ftrace_func_t func
);
579 extern void ftrace_caller(void);
580 extern void ftrace_regs_caller(void);
581 extern void ftrace_call(void);
582 extern void ftrace_regs_call(void);
583 extern void mcount_call(void);
585 void ftrace_modify_all_code(int command
);
588 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
591 #ifndef FTRACE_GRAPH_ADDR
592 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
595 #ifndef FTRACE_REGS_ADDR
596 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
597 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
599 # define FTRACE_REGS_ADDR FTRACE_ADDR
604 * If an arch would like functions that are only traced
605 * by the function graph tracer to jump directly to its own
606 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
607 * to be that address to jump to.
609 #ifndef FTRACE_GRAPH_TRAMP_ADDR
610 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
613 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
614 extern void ftrace_graph_caller(void);
615 extern int ftrace_enable_ftrace_graph_caller(void);
616 extern int ftrace_disable_ftrace_graph_caller(void);
618 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
619 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
623 * ftrace_make_nop - convert code into nop
624 * @mod: module structure if called by module load initialization
625 * @rec: the call site record (e.g. mcount/fentry)
626 * @addr: the address that the call site should be calling
628 * This is a very sensitive operation and great care needs
629 * to be taken by the arch. The operation should carefully
630 * read the location, check to see if what is read is indeed
631 * what we expect it to be, and then on success of the compare,
632 * it should write to the location.
634 * The code segment at @rec->ip should be a caller to @addr
638 * -EFAULT on error reading the location
639 * -EINVAL on a failed compare of the contents
640 * -EPERM on error writing to the location
641 * Any other value will be considered a failure.
643 extern int ftrace_make_nop(struct module
*mod
,
644 struct dyn_ftrace
*rec
, unsigned long addr
);
647 * ftrace_need_init_nop - return whether nop call sites should be initialized
649 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't
650 * need to call ftrace_init_nop() if the code is built with that flag.
651 * Architectures where this is not always the case may define their own
655 * 0 if ftrace_init_nop() should be called
656 * Nonzero if ftrace_init_nop() should not be called
659 #ifndef ftrace_need_init_nop
660 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT))
664 * ftrace_init_nop - initialize a nop call site
665 * @mod: module structure if called by module load initialization
666 * @rec: the call site record (e.g. mcount/fentry)
668 * This is a very sensitive operation and great care needs
669 * to be taken by the arch. The operation should carefully
670 * read the location, check to see if what is read is indeed
671 * what we expect it to be, and then on success of the compare,
672 * it should write to the location.
674 * The code segment at @rec->ip should contain the contents created by
679 * -EFAULT on error reading the location
680 * -EINVAL on a failed compare of the contents
681 * -EPERM on error writing to the location
682 * Any other value will be considered a failure.
684 #ifndef ftrace_init_nop
685 static inline int ftrace_init_nop(struct module
*mod
, struct dyn_ftrace
*rec
)
687 return ftrace_make_nop(mod
, rec
, MCOUNT_ADDR
);
692 * ftrace_make_call - convert a nop call site into a call to addr
693 * @rec: the call site record (e.g. mcount/fentry)
694 * @addr: the address that the call site should call
696 * This is a very sensitive operation and great care needs
697 * to be taken by the arch. The operation should carefully
698 * read the location, check to see if what is read is indeed
699 * what we expect it to be, and then on success of the compare,
700 * it should write to the location.
702 * The code segment at @rec->ip should be a nop
706 * -EFAULT on error reading the location
707 * -EINVAL on a failed compare of the contents
708 * -EPERM on error writing to the location
709 * Any other value will be considered a failure.
711 extern int ftrace_make_call(struct dyn_ftrace
*rec
, unsigned long addr
);
713 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
715 * ftrace_modify_call - convert from one addr to another (no nop)
716 * @rec: the call site record (e.g. mcount/fentry)
717 * @old_addr: the address expected to be currently called to
718 * @addr: the address to change to
720 * This is a very sensitive operation and great care needs
721 * to be taken by the arch. The operation should carefully
722 * read the location, check to see if what is read is indeed
723 * what we expect it to be, and then on success of the compare,
724 * it should write to the location.
726 * The code segment at @rec->ip should be a caller to @old_addr
730 * -EFAULT on error reading the location
731 * -EINVAL on a failed compare of the contents
732 * -EPERM on error writing to the location
733 * Any other value will be considered a failure.
735 extern int ftrace_modify_call(struct dyn_ftrace
*rec
, unsigned long old_addr
,
738 /* Should never be called */
739 static inline int ftrace_modify_call(struct dyn_ftrace
*rec
, unsigned long old_addr
,
746 /* May be defined in arch */
747 extern int ftrace_arch_read_dyn_info(char *buf
, int size
);
749 extern int skip_trace(unsigned long ip
);
750 extern void ftrace_module_init(struct module
*mod
);
751 extern void ftrace_module_enable(struct module
*mod
);
752 extern void ftrace_release_mod(struct module
*mod
);
754 extern void ftrace_disable_daemon(void);
755 extern void ftrace_enable_daemon(void);
756 #else /* CONFIG_DYNAMIC_FTRACE */
757 static inline int skip_trace(unsigned long ip
) { return 0; }
758 static inline void ftrace_disable_daemon(void) { }
759 static inline void ftrace_enable_daemon(void) { }
760 static inline void ftrace_module_init(struct module
*mod
) { }
761 static inline void ftrace_module_enable(struct module
*mod
) { }
762 static inline void ftrace_release_mod(struct module
*mod
) { }
763 static inline int ftrace_text_reserved(const void *start
, const void *end
)
767 static inline unsigned long ftrace_location(unsigned long ip
)
773 * Again users of functions that have ftrace_ops may not
774 * have them defined when ftrace is not enabled, but these
775 * functions may still be called. Use a macro instead of inline.
777 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
778 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
779 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
780 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
781 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
782 #define ftrace_free_filter(ops) do { } while (0)
783 #define ftrace_ops_set_global_filter(ops) do { } while (0)
785 static inline ssize_t
ftrace_filter_write(struct file
*file
, const char __user
*ubuf
,
786 size_t cnt
, loff_t
*ppos
) { return -ENODEV
; }
787 static inline ssize_t
ftrace_notrace_write(struct file
*file
, const char __user
*ubuf
,
788 size_t cnt
, loff_t
*ppos
) { return -ENODEV
; }
790 ftrace_regex_release(struct inode
*inode
, struct file
*file
) { return -ENODEV
; }
792 static inline bool is_ftrace_trampoline(unsigned long addr
)
796 #endif /* CONFIG_DYNAMIC_FTRACE */
798 /* totally disable ftrace - can not re-enable after this */
799 void ftrace_kill(void);
801 static inline void tracer_disable(void)
803 #ifdef CONFIG_FUNCTION_TRACER
809 * Ftrace disable/restore without lock. Some synchronization mechanism
810 * must be used to prevent ftrace_enabled to be changed between
813 static inline int __ftrace_enabled_save(void)
815 #ifdef CONFIG_FUNCTION_TRACER
816 int saved_ftrace_enabled
= ftrace_enabled
;
818 return saved_ftrace_enabled
;
824 static inline void __ftrace_enabled_restore(int enabled
)
826 #ifdef CONFIG_FUNCTION_TRACER
827 ftrace_enabled
= enabled
;
831 /* All archs should have this, but we define it for consistency */
832 #ifndef ftrace_return_address0
833 # define ftrace_return_address0 __builtin_return_address(0)
836 /* Archs may use other ways for ADDR1 and beyond */
837 #ifndef ftrace_return_address
838 # ifdef CONFIG_FRAME_POINTER
839 # define ftrace_return_address(n) __builtin_return_address(n)
841 # define ftrace_return_address(n) 0UL
845 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
846 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
847 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
848 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
849 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
850 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
851 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
853 static inline unsigned long get_lock_parent_ip(void)
855 unsigned long addr
= CALLER_ADDR0
;
857 if (!in_lock_functions(addr
))
860 if (!in_lock_functions(addr
))
865 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
866 extern void trace_preempt_on(unsigned long a0
, unsigned long a1
);
867 extern void trace_preempt_off(unsigned long a0
, unsigned long a1
);
870 * Use defines instead of static inlines because some arches will make code out
871 * of the CALLER_ADDR, when we really want these to be a real nop.
873 # define trace_preempt_on(a0, a1) do { } while (0)
874 # define trace_preempt_off(a0, a1) do { } while (0)
877 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
878 extern void ftrace_init(void);
879 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
880 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
882 #define FTRACE_CALLSITE_SECTION "__mcount_loc"
885 static inline void ftrace_init(void) { }
889 * Structure that defines an entry function trace.
890 * It's already packed but the attribute "packed" is needed
891 * to remove extra padding at the end.
893 struct ftrace_graph_ent
{
894 unsigned long func
; /* Current function */
899 * Structure that defines a return function trace.
900 * It's already packed but the attribute "packed" is needed
901 * to remove extra padding at the end.
903 struct ftrace_graph_ret
{
904 unsigned long func
; /* Current function */
906 /* Number of functions that overran the depth limit for current task */
907 unsigned int overrun
;
908 unsigned long long calltime
;
909 unsigned long long rettime
;
912 /* Type of the callback handlers for tracing function graph*/
913 typedef void (*trace_func_graph_ret_t
)(struct ftrace_graph_ret
*); /* return */
914 typedef int (*trace_func_graph_ent_t
)(struct ftrace_graph_ent
*); /* entry */
916 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent
*trace
);
918 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
921 trace_func_graph_ent_t entryfunc
;
922 trace_func_graph_ret_t retfunc
;
926 * Stack of return addresses for functions
928 * Used in struct thread_info
930 struct ftrace_ret_stack
{
933 unsigned long long calltime
;
934 #ifdef CONFIG_FUNCTION_PROFILER
935 unsigned long long subtime
;
937 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
940 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
946 * Primary handler of a function return.
947 * It relays on ftrace_return_to_handler.
948 * Defined in entry_32/64.S
950 extern void return_to_handler(void);
953 function_graph_enter(unsigned long ret
, unsigned long func
,
954 unsigned long frame_pointer
, unsigned long *retp
);
956 struct ftrace_ret_stack
*
957 ftrace_graph_get_ret_stack(struct task_struct
*task
, int idx
);
959 unsigned long ftrace_graph_ret_addr(struct task_struct
*task
, int *idx
,
960 unsigned long ret
, unsigned long *retp
);
963 * Sometimes we don't want to trace a function with the function
964 * graph tracer but we want them to keep traced by the usual function
965 * tracer if the function graph tracer is not configured.
967 #define __notrace_funcgraph notrace
969 #define FTRACE_RETFUNC_DEPTH 50
970 #define FTRACE_RETSTACK_ALLOC_SIZE 32
972 extern int register_ftrace_graph(struct fgraph_ops
*ops
);
973 extern void unregister_ftrace_graph(struct fgraph_ops
*ops
);
975 extern bool ftrace_graph_is_dead(void);
976 extern void ftrace_graph_stop(void);
978 /* The current handlers in use */
979 extern trace_func_graph_ret_t ftrace_graph_return
;
980 extern trace_func_graph_ent_t ftrace_graph_entry
;
982 extern void ftrace_graph_init_task(struct task_struct
*t
);
983 extern void ftrace_graph_exit_task(struct task_struct
*t
);
984 extern void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
);
986 static inline void pause_graph_tracing(void)
988 atomic_inc(¤t
->tracing_graph_pause
);
991 static inline void unpause_graph_tracing(void)
993 atomic_dec(¤t
->tracing_graph_pause
);
995 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
997 #define __notrace_funcgraph
999 static inline void ftrace_graph_init_task(struct task_struct
*t
) { }
1000 static inline void ftrace_graph_exit_task(struct task_struct
*t
) { }
1001 static inline void ftrace_graph_init_idle_task(struct task_struct
*t
, int cpu
) { }
1003 /* Define as macros as fgraph_ops may not be defined */
1004 #define register_ftrace_graph(ops) ({ -1; })
1005 #define unregister_ftrace_graph(ops) do { } while (0)
1007 static inline unsigned long
1008 ftrace_graph_ret_addr(struct task_struct
*task
, int *idx
, unsigned long ret
,
1009 unsigned long *retp
)
1014 static inline void pause_graph_tracing(void) { }
1015 static inline void unpause_graph_tracing(void) { }
1016 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1018 #ifdef CONFIG_TRACING
1020 /* flags for current->trace */
1022 TSK_TRACE_FL_TRACE_BIT
= 0,
1023 TSK_TRACE_FL_GRAPH_BIT
= 1,
1026 TSK_TRACE_FL_TRACE
= 1 << TSK_TRACE_FL_TRACE_BIT
,
1027 TSK_TRACE_FL_GRAPH
= 1 << TSK_TRACE_FL_GRAPH_BIT
,
1030 static inline void set_tsk_trace_trace(struct task_struct
*tsk
)
1032 set_bit(TSK_TRACE_FL_TRACE_BIT
, &tsk
->trace
);
1035 static inline void clear_tsk_trace_trace(struct task_struct
*tsk
)
1037 clear_bit(TSK_TRACE_FL_TRACE_BIT
, &tsk
->trace
);
1040 static inline int test_tsk_trace_trace(struct task_struct
*tsk
)
1042 return tsk
->trace
& TSK_TRACE_FL_TRACE
;
1045 static inline void set_tsk_trace_graph(struct task_struct
*tsk
)
1047 set_bit(TSK_TRACE_FL_GRAPH_BIT
, &tsk
->trace
);
1050 static inline void clear_tsk_trace_graph(struct task_struct
*tsk
)
1052 clear_bit(TSK_TRACE_FL_GRAPH_BIT
, &tsk
->trace
);
1055 static inline int test_tsk_trace_graph(struct task_struct
*tsk
)
1057 return tsk
->trace
& TSK_TRACE_FL_GRAPH
;
1060 enum ftrace_dump_mode
;
1062 extern enum ftrace_dump_mode ftrace_dump_on_oops
;
1063 extern int tracepoint_printk
;
1065 extern void disable_trace_on_warning(void);
1066 extern int __disable_trace_on_warning
;
1068 int tracepoint_printk_sysctl(struct ctl_table
*table
, int write
,
1069 void *buffer
, size_t *lenp
, loff_t
*ppos
);
1071 #else /* CONFIG_TRACING */
1072 static inline void disable_trace_on_warning(void) { }
1073 #endif /* CONFIG_TRACING */
1075 #ifdef CONFIG_FTRACE_SYSCALLS
1077 unsigned long arch_syscall_addr(int nr
);
1079 #endif /* CONFIG_FTRACE_SYSCALLS */
1081 #endif /* _LINUX_FTRACE_H */