1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Ftrace header. For implementation details beyond the random comments
4 * scattered below, see: Documentation/trace/ftrace-design.rst
5 */
6
7 #ifndef _LINUX_FTRACE_H
8 #define _LINUX_FTRACE_H
9
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>
21 #include <linux/fs.h>
22
23 #include <asm/ftrace.h>
24
25 /*
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.
29 */
30 #ifndef ARCH_SUPPORTS_FTRACE_OPS
31 #define ARCH_SUPPORTS_FTRACE_OPS 0
32 #endif
33
34 #ifdef CONFIG_TRACING
35 extern void ftrace_boot_snapshot(void);
36 #else
ftrace_boot_snapshot(void)37 static inline void ftrace_boot_snapshot(void) { }
38 #endif
39
40 struct ftrace_ops;
41 struct ftrace_regs;
42 struct dyn_ftrace;
43
44 #ifdef CONFIG_FUNCTION_TRACER
45 /*
46 * If the arch's mcount caller does not support all of ftrace's
47 * features, then it must call an indirect function that
48 * does. Or at least does enough to prevent any unwelcome side effects.
49 *
50 * Also define the function prototype that these architectures use
51 * to call the ftrace_ops_list_func().
52 */
53 #if !ARCH_SUPPORTS_FTRACE_OPS
54 # define FTRACE_FORCE_LIST_FUNC 1
55 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
56 #else
57 # define FTRACE_FORCE_LIST_FUNC 0
58 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
59 struct ftrace_ops *op, struct ftrace_regs *fregs);
60 #endif
61 extern const struct ftrace_ops ftrace_nop_ops;
62 extern const struct ftrace_ops ftrace_list_ops;
63 struct ftrace_ops *ftrace_find_unique_ops(struct dyn_ftrace *rec);
64 #endif /* CONFIG_FUNCTION_TRACER */
65
66 /* Main tracing buffer and events set up */
67 #ifdef CONFIG_TRACING
68 void trace_init(void);
69 void early_trace_init(void);
70 #else
trace_init(void)71 static inline void trace_init(void) { }
early_trace_init(void)72 static inline void early_trace_init(void) { }
73 #endif
74
75 struct module;
76 struct ftrace_hash;
77 struct ftrace_direct_func;
78
79 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
80 defined(CONFIG_DYNAMIC_FTRACE)
81 const char *
82 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
83 unsigned long *off, char **modname, char *sym);
84 #else
85 static inline const char *
ftrace_mod_address_lookup(unsigned long addr,unsigned long * size,unsigned long * off,char ** modname,char * sym)86 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
87 unsigned long *off, char **modname, char *sym)
88 {
89 return NULL;
90 }
91 #endif
92
93 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
94 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
95 char *type, char *name,
96 char *module_name, int *exported);
97 #else
ftrace_mod_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)98 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
99 char *type, char *name,
100 char *module_name, int *exported)
101 {
102 return -1;
103 }
104 #endif
105
106 #ifdef CONFIG_FUNCTION_TRACER
107
108 extern int ftrace_enabled;
109
110 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
111
112 struct ftrace_regs {
113 struct pt_regs regs;
114 };
115 #define arch_ftrace_get_regs(fregs) (&(fregs)->regs)
116
117 /*
118 * ftrace_regs_set_instruction_pointer() is to be defined by the architecture
119 * if to allow setting of the instruction pointer from the ftrace_regs when
120 * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching.
121 */
122 #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0)
123 #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
124
ftrace_get_regs(struct ftrace_regs * fregs)125 static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
126 {
127 if (!fregs)
128 return NULL;
129
130 return arch_ftrace_get_regs(fregs);
131 }
132
133 /*
134 * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs.
135 * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs.
136 */
ftrace_regs_has_args(struct ftrace_regs * fregs)137 static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs)
138 {
139 if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS))
140 return true;
141
142 return ftrace_get_regs(fregs) != NULL;
143 }
144
145 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
146 #define ftrace_regs_get_instruction_pointer(fregs) \
147 instruction_pointer(ftrace_get_regs(fregs))
148 #define ftrace_regs_get_argument(fregs, n) \
149 regs_get_kernel_argument(ftrace_get_regs(fregs), n)
150 #define ftrace_regs_get_stack_pointer(fregs) \
151 kernel_stack_pointer(ftrace_get_regs(fregs))
152 #define ftrace_regs_return_value(fregs) \
153 regs_return_value(ftrace_get_regs(fregs))
154 #define ftrace_regs_set_return_value(fregs, ret) \
155 regs_set_return_value(ftrace_get_regs(fregs), ret)
156 #define ftrace_override_function_with_return(fregs) \
157 override_function_with_return(ftrace_get_regs(fregs))
158 #define ftrace_regs_query_register_offset(name) \
159 regs_query_register_offset(name)
160 #endif
161
162 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
163 struct ftrace_ops *op, struct ftrace_regs *fregs);
164
165 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
166
167 /*
168 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
169 * set in the flags member.
170 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and
171 * IPMODIFY are a kind of attribute flags which can be set only before
172 * registering the ftrace_ops, and can not be modified while registered.
173 * Changing those attribute flags after registering ftrace_ops will
174 * cause unexpected results.
175 *
176 * ENABLED - set/unset when ftrace_ops is registered/unregistered
177 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
178 * allocated ftrace_ops which need special care
179 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
180 * and passed to the callback. If this flag is set, but the
181 * architecture does not support passing regs
182 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
183 * ftrace_ops will fail to register, unless the next flag
184 * is set.
185 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
186 * handler can handle an arch that does not save regs
187 * (the handler tests if regs == NULL), then it can set
188 * this flag instead. It will not fail registering the ftrace_ops
189 * but, the regs field will be NULL if the arch does not support
190 * passing regs to the handler.
191 * Note, if this flag is set, the SAVE_REGS flag will automatically
192 * get set upon registering the ftrace_ops, if the arch supports it.
193 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure
194 * that the call back needs recursion protection. If it does
195 * not set this, then the ftrace infrastructure will assume
196 * that the callback can handle recursion on its own.
197 * STUB - The ftrace_ops is just a place holder.
198 * INITIALIZED - The ftrace_ops has already been initialized (first use time
199 * register_ftrace_function() is called, it will initialized the ops)
200 * DELETED - The ops are being deleted, do not let them be registered again.
201 * ADDING - The ops is in the process of being added.
202 * REMOVING - The ops is in the process of being removed.
203 * MODIFYING - The ops is in the process of changing its filter functions.
204 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
205 * The arch specific code sets this flag when it allocated a
206 * trampoline. This lets the arch know that it can update the
207 * trampoline in case the callback function changes.
208 * The ftrace_ops trampoline can be set by the ftrace users, and
209 * in such cases the arch must not modify it. Only the arch ftrace
210 * core code should set this flag.
211 * IPMODIFY - The ops can modify the IP register. This can only be set with
212 * SAVE_REGS. If another ops with this flag set is already registered
213 * for any of the functions that this ops will be registered for, then
214 * this ops will fail to register or set_filter_ip.
215 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
216 * RCU - Set when the ops can only be called when RCU is watching.
217 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
218 * PERMANENT - Set when the ops is permanent and should not be affected by
219 * ftrace_enabled.
220 * DIRECT - Used by the direct ftrace_ops helper for direct functions
221 * (internal ftrace only, should not be used by others)
222 */
223 enum {
224 FTRACE_OPS_FL_ENABLED = BIT(0),
225 FTRACE_OPS_FL_DYNAMIC = BIT(1),
226 FTRACE_OPS_FL_SAVE_REGS = BIT(2),
227 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3),
228 FTRACE_OPS_FL_RECURSION = BIT(4),
229 FTRACE_OPS_FL_STUB = BIT(5),
230 FTRACE_OPS_FL_INITIALIZED = BIT(6),
231 FTRACE_OPS_FL_DELETED = BIT(7),
232 FTRACE_OPS_FL_ADDING = BIT(8),
233 FTRACE_OPS_FL_REMOVING = BIT(9),
234 FTRACE_OPS_FL_MODIFYING = BIT(10),
235 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11),
236 FTRACE_OPS_FL_IPMODIFY = BIT(12),
237 FTRACE_OPS_FL_PID = BIT(13),
238 FTRACE_OPS_FL_RCU = BIT(14),
239 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15),
240 FTRACE_OPS_FL_PERMANENT = BIT(16),
241 FTRACE_OPS_FL_DIRECT = BIT(17),
242 };
243
244 /*
245 * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes
246 * to a ftrace_ops. Note, the requests may fail.
247 *
248 * ENABLE_SHARE_IPMODIFY_SELF - enable a DIRECT ops to work on the same
249 * function as an ops with IPMODIFY. Called
250 * when the DIRECT ops is being registered.
251 * This is called with both direct_mutex and
252 * ftrace_lock are locked.
253 *
254 * ENABLE_SHARE_IPMODIFY_PEER - enable a DIRECT ops to work on the same
255 * function as an ops with IPMODIFY. Called
256 * when the other ops (the one with IPMODIFY)
257 * is being registered.
258 * This is called with direct_mutex locked.
259 *
260 * DISABLE_SHARE_IPMODIFY_PEER - disable a DIRECT ops to work on the same
261 * function as an ops with IPMODIFY. Called
262 * when the other ops (the one with IPMODIFY)
263 * is being unregistered.
264 * This is called with direct_mutex locked.
265 */
266 enum ftrace_ops_cmd {
267 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF,
268 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER,
269 FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER,
270 };
271
272 /*
273 * For most ftrace_ops_cmd,
274 * Returns:
275 * 0 - Success.
276 * Negative on failure. The return value is dependent on the
277 * callback.
278 */
279 typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd cmd);
280
281 #ifdef CONFIG_DYNAMIC_FTRACE
282 /* The hash used to know what functions callbacks trace */
283 struct ftrace_ops_hash {
284 struct ftrace_hash __rcu *notrace_hash;
285 struct ftrace_hash __rcu *filter_hash;
286 struct mutex regex_lock;
287 };
288
289 void ftrace_free_init_mem(void);
290 void ftrace_free_mem(struct module *mod, void *start, void *end);
291 #else
ftrace_free_init_mem(void)292 static inline void ftrace_free_init_mem(void)
293 {
294 ftrace_boot_snapshot();
295 }
ftrace_free_mem(struct module * mod,void * start,void * end)296 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
297 #endif
298
299 /*
300 * Note, ftrace_ops can be referenced outside of RCU protection, unless
301 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
302 * core data, the unregistering of it will perform a scheduling on all CPUs
303 * to make sure that there are no more users. Depending on the load of the
304 * system that may take a bit of time.
305 *
306 * Any private data added must also take care not to be freed and if private
307 * data is added to a ftrace_ops that is in core code, the user of the
308 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
309 */
310 struct ftrace_ops {
311 ftrace_func_t func;
312 struct ftrace_ops __rcu *next;
313 unsigned long flags;
314 void *private;
315 ftrace_func_t saved_func;
316 #ifdef CONFIG_DYNAMIC_FTRACE
317 struct ftrace_ops_hash local_hash;
318 struct ftrace_ops_hash *func_hash;
319 struct ftrace_ops_hash old_hash;
320 unsigned long trampoline;
321 unsigned long trampoline_size;
322 struct list_head list;
323 ftrace_ops_func_t ops_func;
324 #endif
325 };
326
327 extern struct ftrace_ops __rcu *ftrace_ops_list;
328 extern struct ftrace_ops ftrace_list_end;
329
330 /*
331 * Traverse the ftrace_ops_list, invoking all entries. The reason that we
332 * can use rcu_dereference_raw_check() is that elements removed from this list
333 * are simply leaked, so there is no need to interact with a grace-period
334 * mechanism. The rcu_dereference_raw_check() calls are needed to handle
335 * concurrent insertions into the ftrace_ops_list.
336 *
337 * Silly Alpha and silly pointer-speculation compiler optimizations!
338 */
339 #define do_for_each_ftrace_op(op, list) \
340 op = rcu_dereference_raw_check(list); \
341 do
342
343 /*
344 * Optimized for just a single item in the list (as that is the normal case).
345 */
346 #define while_for_each_ftrace_op(op) \
347 while (likely(op = rcu_dereference_raw_check((op)->next)) && \
348 unlikely((op) != &ftrace_list_end))
349
350 /*
351 * Type of the current tracing.
352 */
353 enum ftrace_tracing_type_t {
354 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
355 FTRACE_TYPE_RETURN, /* Hook the return of the function */
356 };
357
358 /* Current tracing type, default is FTRACE_TYPE_ENTER */
359 extern enum ftrace_tracing_type_t ftrace_tracing_type;
360
361 /*
362 * The ftrace_ops must be a static and should also
363 * be read_mostly. These functions do modify read_mostly variables
364 * so use them sparely. Never free an ftrace_op or modify the
365 * next pointer after it has been registered. Even after unregistering
366 * it, the next pointer may still be used internally.
367 */
368 int register_ftrace_function(struct ftrace_ops *ops);
369 int unregister_ftrace_function(struct ftrace_ops *ops);
370
371 extern void ftrace_stub(unsigned long a0, unsigned long a1,
372 struct ftrace_ops *op, struct ftrace_regs *fregs);
373
374
375 int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs);
376 #else /* !CONFIG_FUNCTION_TRACER */
377 /*
378 * (un)register_ftrace_function must be a macro since the ops parameter
379 * must not be evaluated.
380 */
381 #define register_ftrace_function(ops) ({ 0; })
382 #define unregister_ftrace_function(ops) ({ 0; })
ftrace_kill(void)383 static inline void ftrace_kill(void) { }
ftrace_free_init_mem(void)384 static inline void ftrace_free_init_mem(void) { }
ftrace_free_mem(struct module * mod,void * start,void * end)385 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
ftrace_lookup_symbols(const char ** sorted_syms,size_t cnt,unsigned long * addrs)386 static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
387 {
388 return -EOPNOTSUPP;
389 }
390 #endif /* CONFIG_FUNCTION_TRACER */
391
392 struct ftrace_func_entry {
393 struct hlist_node hlist;
394 unsigned long ip;
395 unsigned long direct; /* for direct lookup only */
396 };
397
398 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
399 extern int ftrace_direct_func_count;
400 int register_ftrace_direct(unsigned long ip, unsigned long addr);
401 int unregister_ftrace_direct(unsigned long ip, unsigned long addr);
402 int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr);
403 struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr);
404 int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
405 struct dyn_ftrace *rec,
406 unsigned long old_addr,
407 unsigned long new_addr);
408 unsigned long ftrace_find_rec_direct(unsigned long ip);
409 int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
410 int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
411 int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
412 int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr);
413
414 #else
415 struct ftrace_ops;
416 # define ftrace_direct_func_count 0
register_ftrace_direct(unsigned long ip,unsigned long addr)417 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
418 {
419 return -ENOTSUPP;
420 }
unregister_ftrace_direct(unsigned long ip,unsigned long addr)421 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
422 {
423 return -ENOTSUPP;
424 }
modify_ftrace_direct(unsigned long ip,unsigned long old_addr,unsigned long new_addr)425 static inline int modify_ftrace_direct(unsigned long ip,
426 unsigned long old_addr, unsigned long new_addr)
427 {
428 return -ENOTSUPP;
429 }
ftrace_find_direct_func(unsigned long addr)430 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
431 {
432 return NULL;
433 }
ftrace_modify_direct_caller(struct ftrace_func_entry * entry,struct dyn_ftrace * rec,unsigned long old_addr,unsigned long new_addr)434 static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
435 struct dyn_ftrace *rec,
436 unsigned long old_addr,
437 unsigned long new_addr)
438 {
439 return -ENODEV;
440 }
ftrace_find_rec_direct(unsigned long ip)441 static inline unsigned long ftrace_find_rec_direct(unsigned long ip)
442 {
443 return 0;
444 }
register_ftrace_direct_multi(struct ftrace_ops * ops,unsigned long addr)445 static inline int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
446 {
447 return -ENODEV;
448 }
unregister_ftrace_direct_multi(struct ftrace_ops * ops,unsigned long addr)449 static inline int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
450 {
451 return -ENODEV;
452 }
modify_ftrace_direct_multi(struct ftrace_ops * ops,unsigned long addr)453 static inline int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
454 {
455 return -ENODEV;
456 }
modify_ftrace_direct_multi_nolock(struct ftrace_ops * ops,unsigned long addr)457 static inline int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr)
458 {
459 return -ENODEV;
460 }
461
462 /*
463 * This must be implemented by the architecture.
464 * It is the way the ftrace direct_ops helper, when called
465 * via ftrace (because there's other callbacks besides the
466 * direct call), can inform the architecture's trampoline that this
467 * routine has a direct caller, and what the caller is.
468 *
469 * For example, in x86, it returns the direct caller
470 * callback function via the regs->orig_ax parameter.
471 * Then in the ftrace trampoline, if this is set, it makes
472 * the return from the trampoline jump to the direct caller
473 * instead of going back to the function it just traced.
474 */
arch_ftrace_set_direct_caller(struct ftrace_regs * fregs,unsigned long addr)475 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs,
476 unsigned long addr) { }
477 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
478
479 #ifdef CONFIG_STACK_TRACER
480
481 extern int stack_tracer_enabled;
482
483 int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer,
484 size_t *lenp, loff_t *ppos);
485
486 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
487 DECLARE_PER_CPU(int, disable_stack_tracer);
488
489 /**
490 * stack_tracer_disable - temporarily disable the stack tracer
491 *
492 * There's a few locations (namely in RCU) where stack tracing
493 * cannot be executed. This function is used to disable stack
494 * tracing during those critical sections.
495 *
496 * This function must be called with preemption or interrupts
497 * disabled and stack_tracer_enable() must be called shortly after
498 * while preemption or interrupts are still disabled.
499 */
stack_tracer_disable(void)500 static inline void stack_tracer_disable(void)
501 {
502 /* Preemption or interrupts must be disabled */
503 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
504 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
505 this_cpu_inc(disable_stack_tracer);
506 }
507
508 /**
509 * stack_tracer_enable - re-enable the stack tracer
510 *
511 * After stack_tracer_disable() is called, stack_tracer_enable()
512 * must be called shortly afterward.
513 */
stack_tracer_enable(void)514 static inline void stack_tracer_enable(void)
515 {
516 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
517 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
518 this_cpu_dec(disable_stack_tracer);
519 }
520 #else
stack_tracer_disable(void)521 static inline void stack_tracer_disable(void) { }
stack_tracer_enable(void)522 static inline void stack_tracer_enable(void) { }
523 #endif
524
525 #ifdef CONFIG_DYNAMIC_FTRACE
526
527 void ftrace_arch_code_modify_prepare(void);
528 void ftrace_arch_code_modify_post_process(void);
529
530 enum ftrace_bug_type {
531 FTRACE_BUG_UNKNOWN,
532 FTRACE_BUG_INIT,
533 FTRACE_BUG_NOP,
534 FTRACE_BUG_CALL,
535 FTRACE_BUG_UPDATE,
536 };
537 extern enum ftrace_bug_type ftrace_bug_type;
538
539 /*
540 * Archs can set this to point to a variable that holds the value that was
541 * expected at the call site before calling ftrace_bug().
542 */
543 extern const void *ftrace_expected;
544
545 void ftrace_bug(int err, struct dyn_ftrace *rec);
546
547 struct seq_file;
548
549 extern int ftrace_text_reserved(const void *start, const void *end);
550
551 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
552
553 bool is_ftrace_trampoline(unsigned long addr);
554
555 /*
556 * The dyn_ftrace record's flags field is split into two parts.
557 * the first part which is '0-FTRACE_REF_MAX' is a counter of
558 * the number of callbacks that have registered the function that
559 * the dyn_ftrace descriptor represents.
560 *
561 * The second part is a mask:
562 * ENABLED - the function is being traced
563 * REGS - the record wants the function to save regs
564 * REGS_EN - the function is set up to save regs.
565 * IPMODIFY - the record allows for the IP address to be changed.
566 * DISABLED - the record is not ready to be touched yet
567 * DIRECT - there is a direct function to call
568 * CALL_OPS - the record can use callsite-specific ops
569 * CALL_OPS_EN - the function is set up to use callsite-specific ops
570 *
571 * When a new ftrace_ops is registered and wants a function to save
572 * pt_regs, the rec->flags REGS is set. When the function has been
573 * set up to save regs, the REG_EN flag is set. Once a function
574 * starts saving regs it will do so until all ftrace_ops are removed
575 * from tracing that function.
576 */
577 enum {
578 FTRACE_FL_ENABLED = (1UL << 31),
579 FTRACE_FL_REGS = (1UL << 30),
580 FTRACE_FL_REGS_EN = (1UL << 29),
581 FTRACE_FL_TRAMP = (1UL << 28),
582 FTRACE_FL_TRAMP_EN = (1UL << 27),
583 FTRACE_FL_IPMODIFY = (1UL << 26),
584 FTRACE_FL_DISABLED = (1UL << 25),
585 FTRACE_FL_DIRECT = (1UL << 24),
586 FTRACE_FL_DIRECT_EN = (1UL << 23),
587 FTRACE_FL_CALL_OPS = (1UL << 22),
588 FTRACE_FL_CALL_OPS_EN = (1UL << 21),
589 };
590
591 #define FTRACE_REF_MAX_SHIFT 21
592 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
593
594 #define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX)
595
596 struct dyn_ftrace {
597 unsigned long ip; /* address of mcount call-site */
598 unsigned long flags;
599 struct dyn_arch_ftrace arch;
600 };
601
602 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
603 int remove, int reset);
604 int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
605 unsigned int cnt, int remove, int reset);
606 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
607 int len, int reset);
608 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
609 int len, int reset);
610 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
611 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
612 void ftrace_free_filter(struct ftrace_ops *ops);
613 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
614
615 enum {
616 FTRACE_UPDATE_CALLS = (1 << 0),
617 FTRACE_DISABLE_CALLS = (1 << 1),
618 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
619 FTRACE_START_FUNC_RET = (1 << 3),
620 FTRACE_STOP_FUNC_RET = (1 << 4),
621 FTRACE_MAY_SLEEP = (1 << 5),
622 };
623
624 /*
625 * The FTRACE_UPDATE_* enum is used to pass information back
626 * from the ftrace_update_record() and ftrace_test_record()
627 * functions. These are called by the code update routines
628 * to find out what is to be done for a given function.
629 *
630 * IGNORE - The function is already what we want it to be
631 * MAKE_CALL - Start tracing the function
632 * MODIFY_CALL - Stop saving regs for the function
633 * MAKE_NOP - Stop tracing the function
634 */
635 enum {
636 FTRACE_UPDATE_IGNORE,
637 FTRACE_UPDATE_MAKE_CALL,
638 FTRACE_UPDATE_MODIFY_CALL,
639 FTRACE_UPDATE_MAKE_NOP,
640 };
641
642 enum {
643 FTRACE_ITER_FILTER = (1 << 0),
644 FTRACE_ITER_NOTRACE = (1 << 1),
645 FTRACE_ITER_PRINTALL = (1 << 2),
646 FTRACE_ITER_DO_PROBES = (1 << 3),
647 FTRACE_ITER_PROBE = (1 << 4),
648 FTRACE_ITER_MOD = (1 << 5),
649 FTRACE_ITER_ENABLED = (1 << 6),
650 };
651
652 void arch_ftrace_update_code(int command);
653 void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
654 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
655 void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
656
657 struct ftrace_rec_iter;
658
659 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
660 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
661 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
662
663 #define for_ftrace_rec_iter(iter) \
664 for (iter = ftrace_rec_iter_start(); \
665 iter; \
666 iter = ftrace_rec_iter_next(iter))
667
668
669 int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
670 int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
671 void ftrace_run_stop_machine(int command);
672 unsigned long ftrace_location(unsigned long ip);
673 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
674 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
675 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
676
677 extern ftrace_func_t ftrace_trace_function;
678
679 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
680 struct inode *inode, struct file *file);
681 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
682 size_t cnt, loff_t *ppos);
683 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
684 size_t cnt, loff_t *ppos);
685 int ftrace_regex_release(struct inode *inode, struct file *file);
686
687 void __init
688 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
689
690 /* defined in arch */
691 extern int ftrace_ip_converted(unsigned long ip);
692 extern int ftrace_dyn_arch_init(void);
693 extern void ftrace_replace_code(int enable);
694 extern int ftrace_update_ftrace_func(ftrace_func_t func);
695 extern void ftrace_caller(void);
696 extern void ftrace_regs_caller(void);
697 extern void ftrace_call(void);
698 extern void ftrace_regs_call(void);
699 extern void mcount_call(void);
700
701 void ftrace_modify_all_code(int command);
702
703 #ifndef FTRACE_ADDR
704 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
705 #endif
706
707 #ifndef FTRACE_GRAPH_ADDR
708 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
709 #endif
710
711 #ifndef FTRACE_REGS_ADDR
712 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
713 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
714 #else
715 # define FTRACE_REGS_ADDR FTRACE_ADDR
716 #endif
717 #endif
718
719 /*
720 * If an arch would like functions that are only traced
721 * by the function graph tracer to jump directly to its own
722 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
723 * to be that address to jump to.
724 */
725 #ifndef FTRACE_GRAPH_TRAMP_ADDR
726 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
727 #endif
728
729 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
730 extern void ftrace_graph_caller(void);
731 extern int ftrace_enable_ftrace_graph_caller(void);
732 extern int ftrace_disable_ftrace_graph_caller(void);
733 #else
ftrace_enable_ftrace_graph_caller(void)734 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
ftrace_disable_ftrace_graph_caller(void)735 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
736 #endif
737
738 /**
739 * ftrace_make_nop - convert code into nop
740 * @mod: module structure if called by module load initialization
741 * @rec: the call site record (e.g. mcount/fentry)
742 * @addr: the address that the call site should be calling
743 *
744 * This is a very sensitive operation and great care needs
745 * to be taken by the arch. The operation should carefully
746 * read the location, check to see if what is read is indeed
747 * what we expect it to be, and then on success of the compare,
748 * it should write to the location.
749 *
750 * The code segment at @rec->ip should be a caller to @addr
751 *
752 * Return must be:
753 * 0 on success
754 * -EFAULT on error reading the location
755 * -EINVAL on a failed compare of the contents
756 * -EPERM on error writing to the location
757 * Any other value will be considered a failure.
758 */
759 extern int ftrace_make_nop(struct module *mod,
760 struct dyn_ftrace *rec, unsigned long addr);
761
762 /**
763 * ftrace_need_init_nop - return whether nop call sites should be initialized
764 *
765 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't
766 * need to call ftrace_init_nop() if the code is built with that flag.
767 * Architectures where this is not always the case may define their own
768 * condition.
769 *
770 * Return must be:
771 * 0 if ftrace_init_nop() should be called
772 * Nonzero if ftrace_init_nop() should not be called
773 */
774
775 #ifndef ftrace_need_init_nop
776 #define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT))
777 #endif
778
779 /**
780 * ftrace_init_nop - initialize a nop call site
781 * @mod: module structure if called by module load initialization
782 * @rec: the call site record (e.g. mcount/fentry)
783 *
784 * This is a very sensitive operation and great care needs
785 * to be taken by the arch. The operation should carefully
786 * read the location, check to see if what is read is indeed
787 * what we expect it to be, and then on success of the compare,
788 * it should write to the location.
789 *
790 * The code segment at @rec->ip should contain the contents created by
791 * the compiler
792 *
793 * Return must be:
794 * 0 on success
795 * -EFAULT on error reading the location
796 * -EINVAL on a failed compare of the contents
797 * -EPERM on error writing to the location
798 * Any other value will be considered a failure.
799 */
800 #ifndef ftrace_init_nop
ftrace_init_nop(struct module * mod,struct dyn_ftrace * rec)801 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
802 {
803 return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
804 }
805 #endif
806
807 /**
808 * ftrace_make_call - convert a nop call site into a call to addr
809 * @rec: the call site record (e.g. mcount/fentry)
810 * @addr: the address that the call site should call
811 *
812 * This is a very sensitive operation and great care needs
813 * to be taken by the arch. The operation should carefully
814 * read the location, check to see if what is read is indeed
815 * what we expect it to be, and then on success of the compare,
816 * it should write to the location.
817 *
818 * The code segment at @rec->ip should be a nop
819 *
820 * Return must be:
821 * 0 on success
822 * -EFAULT on error reading the location
823 * -EINVAL on a failed compare of the contents
824 * -EPERM on error writing to the location
825 * Any other value will be considered a failure.
826 */
827 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
828
829 #if defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) || \
830 defined(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS)
831 /**
832 * ftrace_modify_call - convert from one addr to another (no nop)
833 * @rec: the call site record (e.g. mcount/fentry)
834 * @old_addr: the address expected to be currently called to
835 * @addr: the address to change to
836 *
837 * This is a very sensitive operation and great care needs
838 * to be taken by the arch. The operation should carefully
839 * read the location, check to see if what is read is indeed
840 * what we expect it to be, and then on success of the compare,
841 * it should write to the location.
842 *
843 * When using call ops, this is called when the associated ops change, even
844 * when (addr == old_addr).
845 *
846 * The code segment at @rec->ip should be a caller to @old_addr
847 *
848 * Return must be:
849 * 0 on success
850 * -EFAULT on error reading the location
851 * -EINVAL on a failed compare of the contents
852 * -EPERM on error writing to the location
853 * Any other value will be considered a failure.
854 */
855 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
856 unsigned long addr);
857 #else
858 /* Should never be called */
ftrace_modify_call(struct dyn_ftrace * rec,unsigned long old_addr,unsigned long addr)859 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
860 unsigned long addr)
861 {
862 return -EINVAL;
863 }
864 #endif
865
866 /* May be defined in arch */
867 extern int ftrace_arch_read_dyn_info(char *buf, int size);
868
869 extern int skip_trace(unsigned long ip);
870 extern void ftrace_module_init(struct module *mod);
871 extern void ftrace_module_enable(struct module *mod);
872 extern void ftrace_release_mod(struct module *mod);
873
874 extern void ftrace_disable_daemon(void);
875 extern void ftrace_enable_daemon(void);
876 #else /* CONFIG_DYNAMIC_FTRACE */
skip_trace(unsigned long ip)877 static inline int skip_trace(unsigned long ip) { return 0; }
ftrace_disable_daemon(void)878 static inline void ftrace_disable_daemon(void) { }
ftrace_enable_daemon(void)879 static inline void ftrace_enable_daemon(void) { }
ftrace_module_init(struct module * mod)880 static inline void ftrace_module_init(struct module *mod) { }
ftrace_module_enable(struct module * mod)881 static inline void ftrace_module_enable(struct module *mod) { }
ftrace_release_mod(struct module * mod)882 static inline void ftrace_release_mod(struct module *mod) { }
ftrace_text_reserved(const void * start,const void * end)883 static inline int ftrace_text_reserved(const void *start, const void *end)
884 {
885 return 0;
886 }
ftrace_location(unsigned long ip)887 static inline unsigned long ftrace_location(unsigned long ip)
888 {
889 return 0;
890 }
891
892 /*
893 * Again users of functions that have ftrace_ops may not
894 * have them defined when ftrace is not enabled, but these
895 * functions may still be called. Use a macro instead of inline.
896 */
897 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
898 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
899 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
900 #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; })
901 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
902 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
903 #define ftrace_free_filter(ops) do { } while (0)
904 #define ftrace_ops_set_global_filter(ops) do { } while (0)
905
ftrace_filter_write(struct file * file,const char __user * ubuf,size_t cnt,loff_t * ppos)906 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
907 size_t cnt, loff_t *ppos) { return -ENODEV; }
ftrace_notrace_write(struct file * file,const char __user * ubuf,size_t cnt,loff_t * ppos)908 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
909 size_t cnt, loff_t *ppos) { return -ENODEV; }
910 static inline int
ftrace_regex_release(struct inode * inode,struct file * file)911 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
912
is_ftrace_trampoline(unsigned long addr)913 static inline bool is_ftrace_trampoline(unsigned long addr)
914 {
915 return false;
916 }
917 #endif /* CONFIG_DYNAMIC_FTRACE */
918
919 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
920 #ifndef ftrace_graph_func
921 #define ftrace_graph_func ftrace_stub
922 #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB
923 #else
924 #define FTRACE_OPS_GRAPH_STUB 0
925 #endif
926 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
927
928 /* totally disable ftrace - can not re-enable after this */
929 void ftrace_kill(void);
930
tracer_disable(void)931 static inline void tracer_disable(void)
932 {
933 #ifdef CONFIG_FUNCTION_TRACER
934 ftrace_enabled = 0;
935 #endif
936 }
937
938 /*
939 * Ftrace disable/restore without lock. Some synchronization mechanism
940 * must be used to prevent ftrace_enabled to be changed between
941 * disable/restore.
942 */
__ftrace_enabled_save(void)943 static inline int __ftrace_enabled_save(void)
944 {
945 #ifdef CONFIG_FUNCTION_TRACER
946 int saved_ftrace_enabled = ftrace_enabled;
947 ftrace_enabled = 0;
948 return saved_ftrace_enabled;
949 #else
950 return 0;
951 #endif
952 }
953
__ftrace_enabled_restore(int enabled)954 static inline void __ftrace_enabled_restore(int enabled)
955 {
956 #ifdef CONFIG_FUNCTION_TRACER
957 ftrace_enabled = enabled;
958 #endif
959 }
960
961 /* All archs should have this, but we define it for consistency */
962 #ifndef ftrace_return_address0
963 # define ftrace_return_address0 __builtin_return_address(0)
964 #endif
965
966 /* Archs may use other ways for ADDR1 and beyond */
967 #ifndef ftrace_return_address
968 # ifdef CONFIG_FRAME_POINTER
969 # define ftrace_return_address(n) __builtin_return_address(n)
970 # else
971 # define ftrace_return_address(n) 0UL
972 # endif
973 #endif
974
975 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
976 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
977 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
978 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
979 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
980 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
981 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
982
get_lock_parent_ip(void)983 static inline unsigned long get_lock_parent_ip(void)
984 {
985 unsigned long addr = CALLER_ADDR0;
986
987 if (!in_lock_functions(addr))
988 return addr;
989 addr = CALLER_ADDR1;
990 if (!in_lock_functions(addr))
991 return addr;
992 return CALLER_ADDR2;
993 }
994
995 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
996 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
997 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
998 #else
999 /*
1000 * Use defines instead of static inlines because some arches will make code out
1001 * of the CALLER_ADDR, when we really want these to be a real nop.
1002 */
1003 # define trace_preempt_on(a0, a1) do { } while (0)
1004 # define trace_preempt_off(a0, a1) do { } while (0)
1005 #endif
1006
1007 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
1008 extern void ftrace_init(void);
1009 #ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
1010 #define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
1011 #else
1012 #define FTRACE_CALLSITE_SECTION "__mcount_loc"
1013 #endif
1014 #else
ftrace_init(void)1015 static inline void ftrace_init(void) { }
1016 #endif
1017
1018 /*
1019 * Structure that defines an entry function trace.
1020 * It's already packed but the attribute "packed" is needed
1021 * to remove extra padding at the end.
1022 */
1023 struct ftrace_graph_ent {
1024 unsigned long func; /* Current function */
1025 int depth;
1026 } __packed;
1027
1028 /*
1029 * Structure that defines a return function trace.
1030 * It's already packed but the attribute "packed" is needed
1031 * to remove extra padding at the end.
1032 */
1033 struct ftrace_graph_ret {
1034 unsigned long func; /* Current function */
1035 int depth;
1036 /* Number of functions that overran the depth limit for current task */
1037 unsigned int overrun;
1038 unsigned long long calltime;
1039 unsigned long long rettime;
1040 } __packed;
1041
1042 /* Type of the callback handlers for tracing function graph*/
1043 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
1044 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
1045
1046 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
1047
1048 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1049
1050 struct fgraph_ops {
1051 trace_func_graph_ent_t entryfunc;
1052 trace_func_graph_ret_t retfunc;
1053 };
1054
1055 /*
1056 * Stack of return addresses for functions
1057 * of a thread.
1058 * Used in struct thread_info
1059 */
1060 struct ftrace_ret_stack {
1061 unsigned long ret;
1062 unsigned long func;
1063 unsigned long long calltime;
1064 #ifdef CONFIG_FUNCTION_PROFILER
1065 unsigned long long subtime;
1066 #endif
1067 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
1068 unsigned long fp;
1069 #endif
1070 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
1071 unsigned long *retp;
1072 #endif
1073 };
1074
1075 /*
1076 * Primary handler of a function return.
1077 * It relays on ftrace_return_to_handler.
1078 * Defined in entry_32/64.S
1079 */
1080 extern void return_to_handler(void);
1081
1082 extern int
1083 function_graph_enter(unsigned long ret, unsigned long func,
1084 unsigned long frame_pointer, unsigned long *retp);
1085
1086 struct ftrace_ret_stack *
1087 ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
1088
1089 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
1090 unsigned long ret, unsigned long *retp);
1091
1092 /*
1093 * Sometimes we don't want to trace a function with the function
1094 * graph tracer but we want them to keep traced by the usual function
1095 * tracer if the function graph tracer is not configured.
1096 */
1097 #define __notrace_funcgraph notrace
1098
1099 #define FTRACE_RETFUNC_DEPTH 50
1100 #define FTRACE_RETSTACK_ALLOC_SIZE 32
1101
1102 extern int register_ftrace_graph(struct fgraph_ops *ops);
1103 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
1104
1105 /**
1106 * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
1107 *
1108 * ftrace_graph_stop() is called when a severe error is detected in
1109 * the function graph tracing. This function is called by the critical
1110 * paths of function graph to keep those paths from doing any more harm.
1111 */
1112 DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph);
1113
ftrace_graph_is_dead(void)1114 static inline bool ftrace_graph_is_dead(void)
1115 {
1116 return static_branch_unlikely(&kill_ftrace_graph);
1117 }
1118
1119 extern void ftrace_graph_stop(void);
1120
1121 /* The current handlers in use */
1122 extern trace_func_graph_ret_t ftrace_graph_return;
1123 extern trace_func_graph_ent_t ftrace_graph_entry;
1124
1125 extern void ftrace_graph_init_task(struct task_struct *t);
1126 extern void ftrace_graph_exit_task(struct task_struct *t);
1127 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
1128
pause_graph_tracing(void)1129 static inline void pause_graph_tracing(void)
1130 {
1131 atomic_inc(¤t->tracing_graph_pause);
1132 }
1133
unpause_graph_tracing(void)1134 static inline void unpause_graph_tracing(void)
1135 {
1136 atomic_dec(¤t->tracing_graph_pause);
1137 }
1138 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
1139
1140 #define __notrace_funcgraph
1141
ftrace_graph_init_task(struct task_struct * t)1142 static inline void ftrace_graph_init_task(struct task_struct *t) { }
ftrace_graph_exit_task(struct task_struct * t)1143 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
ftrace_graph_init_idle_task(struct task_struct * t,int cpu)1144 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
1145
1146 /* Define as macros as fgraph_ops may not be defined */
1147 #define register_ftrace_graph(ops) ({ -1; })
1148 #define unregister_ftrace_graph(ops) do { } while (0)
1149
1150 static inline unsigned long
ftrace_graph_ret_addr(struct task_struct * task,int * idx,unsigned long ret,unsigned long * retp)1151 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
1152 unsigned long *retp)
1153 {
1154 return ret;
1155 }
1156
pause_graph_tracing(void)1157 static inline void pause_graph_tracing(void) { }
unpause_graph_tracing(void)1158 static inline void unpause_graph_tracing(void) { }
1159 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1160
1161 #ifdef CONFIG_TRACING
1162 enum ftrace_dump_mode;
1163
1164 extern enum ftrace_dump_mode ftrace_dump_on_oops;
1165 extern int tracepoint_printk;
1166
1167 extern void disable_trace_on_warning(void);
1168 extern int __disable_trace_on_warning;
1169
1170 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
1171 void *buffer, size_t *lenp, loff_t *ppos);
1172
1173 #else /* CONFIG_TRACING */
disable_trace_on_warning(void)1174 static inline void disable_trace_on_warning(void) { }
1175 #endif /* CONFIG_TRACING */
1176
1177 #ifdef CONFIG_FTRACE_SYSCALLS
1178
1179 unsigned long arch_syscall_addr(int nr);
1180
1181 #endif /* CONFIG_FTRACE_SYSCALLS */
1182
1183 #endif /* _LINUX_FTRACE_H */
1184