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_clock.h>
11 #include <linux/kallsyms.h>
12 #include <linux/linkage.h>
13 #include <linux/bitops.h>
14 #include <linux/ptrace.h>
15 #include <linux/ktime.h>
16 #include <linux/sched.h>
17 #include <linux/types.h>
18 #include <linux/init.h>
19 #include <linux/fs.h>
20
21 #include <asm/ftrace.h>
22
23 /*
24 * If the arch supports passing the variable contents of
25 * function_trace_op as the third parameter back from the
26 * mcount call, then the arch should define this as 1.
27 */
28 #ifndef ARCH_SUPPORTS_FTRACE_OPS
29 #define ARCH_SUPPORTS_FTRACE_OPS 0
30 #endif
31
32 /*
33 * If the arch's mcount caller does not support all of ftrace's
34 * features, then it must call an indirect function that
35 * does. Or at least does enough to prevent any unwelcomed side effects.
36 */
37 #if !ARCH_SUPPORTS_FTRACE_OPS
38 # define FTRACE_FORCE_LIST_FUNC 1
39 #else
40 # define FTRACE_FORCE_LIST_FUNC 0
41 #endif
42
43 /* Main tracing buffer and events set up */
44 #ifdef CONFIG_TRACING
45 void trace_init(void);
46 void early_trace_init(void);
47 #else
trace_init(void)48 static inline void trace_init(void) { }
early_trace_init(void)49 static inline void early_trace_init(void) { }
50 #endif
51
52 struct module;
53 struct ftrace_hash;
54
55 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
56 defined(CONFIG_DYNAMIC_FTRACE)
57 const char *
58 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
59 unsigned long *off, char **modname, char *sym);
60 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
61 char *type, char *name,
62 char *module_name, int *exported);
63 #else
64 static inline const char *
ftrace_mod_address_lookup(unsigned long addr,unsigned long * size,unsigned long * off,char ** modname,char * sym)65 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
66 unsigned long *off, char **modname, char *sym)
67 {
68 return NULL;
69 }
ftrace_mod_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)70 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
71 char *type, char *name,
72 char *module_name, int *exported)
73 {
74 return -1;
75 }
76 #endif
77
78
79 #ifdef CONFIG_FUNCTION_TRACER
80
81 extern int ftrace_enabled;
82 extern int
83 ftrace_enable_sysctl(struct ctl_table *table, int write,
84 void __user *buffer, size_t *lenp,
85 loff_t *ppos);
86
87 struct ftrace_ops;
88
89 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
90 struct ftrace_ops *op, struct pt_regs *regs);
91
92 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
93
94 /*
95 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
96 * set in the flags member.
97 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and
98 * IPMODIFY are a kind of attribute flags which can be set only before
99 * registering the ftrace_ops, and can not be modified while registered.
100 * Changing those attribute flags after registering ftrace_ops will
101 * cause unexpected results.
102 *
103 * ENABLED - set/unset when ftrace_ops is registered/unregistered
104 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
105 * allocated ftrace_ops which need special care
106 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
107 * and passed to the callback. If this flag is set, but the
108 * architecture does not support passing regs
109 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
110 * ftrace_ops will fail to register, unless the next flag
111 * is set.
112 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
113 * handler can handle an arch that does not save regs
114 * (the handler tests if regs == NULL), then it can set
115 * this flag instead. It will not fail registering the ftrace_ops
116 * but, the regs field will be NULL if the arch does not support
117 * passing regs to the handler.
118 * Note, if this flag is set, the SAVE_REGS flag will automatically
119 * get set upon registering the ftrace_ops, if the arch supports it.
120 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
121 * that the call back has its own recursion protection. If it does
122 * not set this, then the ftrace infrastructure will add recursion
123 * protection for the caller.
124 * STUB - The ftrace_ops is just a place holder.
125 * INITIALIZED - The ftrace_ops has already been initialized (first use time
126 * register_ftrace_function() is called, it will initialized the ops)
127 * DELETED - The ops are being deleted, do not let them be registered again.
128 * ADDING - The ops is in the process of being added.
129 * REMOVING - The ops is in the process of being removed.
130 * MODIFYING - The ops is in the process of changing its filter functions.
131 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
132 * The arch specific code sets this flag when it allocated a
133 * trampoline. This lets the arch know that it can update the
134 * trampoline in case the callback function changes.
135 * The ftrace_ops trampoline can be set by the ftrace users, and
136 * in such cases the arch must not modify it. Only the arch ftrace
137 * core code should set this flag.
138 * IPMODIFY - The ops can modify the IP register. This can only be set with
139 * SAVE_REGS. If another ops with this flag set is already registered
140 * for any of the functions that this ops will be registered for, then
141 * this ops will fail to register or set_filter_ip.
142 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
143 * RCU - Set when the ops can only be called when RCU is watching.
144 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
145 */
146 enum {
147 FTRACE_OPS_FL_ENABLED = 1 << 0,
148 FTRACE_OPS_FL_DYNAMIC = 1 << 1,
149 FTRACE_OPS_FL_SAVE_REGS = 1 << 2,
150 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 3,
151 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 4,
152 FTRACE_OPS_FL_STUB = 1 << 5,
153 FTRACE_OPS_FL_INITIALIZED = 1 << 6,
154 FTRACE_OPS_FL_DELETED = 1 << 7,
155 FTRACE_OPS_FL_ADDING = 1 << 8,
156 FTRACE_OPS_FL_REMOVING = 1 << 9,
157 FTRACE_OPS_FL_MODIFYING = 1 << 10,
158 FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 11,
159 FTRACE_OPS_FL_IPMODIFY = 1 << 12,
160 FTRACE_OPS_FL_PID = 1 << 13,
161 FTRACE_OPS_FL_RCU = 1 << 14,
162 FTRACE_OPS_FL_TRACE_ARRAY = 1 << 15,
163 };
164
165 #ifdef CONFIG_DYNAMIC_FTRACE
166 /* The hash used to know what functions callbacks trace */
167 struct ftrace_ops_hash {
168 struct ftrace_hash __rcu *notrace_hash;
169 struct ftrace_hash __rcu *filter_hash;
170 struct mutex regex_lock;
171 };
172
173 void ftrace_free_init_mem(void);
174 void ftrace_free_mem(struct module *mod, void *start, void *end);
175 #else
ftrace_free_init_mem(void)176 static inline void ftrace_free_init_mem(void) { }
ftrace_free_mem(struct module * mod,void * start,void * end)177 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
178 #endif
179
180 /*
181 * Note, ftrace_ops can be referenced outside of RCU protection, unless
182 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
183 * core data, the unregistering of it will perform a scheduling on all CPUs
184 * to make sure that there are no more users. Depending on the load of the
185 * system that may take a bit of time.
186 *
187 * Any private data added must also take care not to be freed and if private
188 * data is added to a ftrace_ops that is in core code, the user of the
189 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
190 */
191 struct ftrace_ops {
192 ftrace_func_t func;
193 struct ftrace_ops __rcu *next;
194 unsigned long flags;
195 void *private;
196 ftrace_func_t saved_func;
197 #ifdef CONFIG_DYNAMIC_FTRACE
198 struct ftrace_ops_hash local_hash;
199 struct ftrace_ops_hash *func_hash;
200 struct ftrace_ops_hash old_hash;
201 unsigned long trampoline;
202 unsigned long trampoline_size;
203 #endif
204 };
205
206 /*
207 * Type of the current tracing.
208 */
209 enum ftrace_tracing_type_t {
210 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
211 FTRACE_TYPE_RETURN, /* Hook the return of the function */
212 };
213
214 /* Current tracing type, default is FTRACE_TYPE_ENTER */
215 extern enum ftrace_tracing_type_t ftrace_tracing_type;
216
217 /*
218 * The ftrace_ops must be a static and should also
219 * be read_mostly. These functions do modify read_mostly variables
220 * so use them sparely. Never free an ftrace_op or modify the
221 * next pointer after it has been registered. Even after unregistering
222 * it, the next pointer may still be used internally.
223 */
224 int register_ftrace_function(struct ftrace_ops *ops);
225 int unregister_ftrace_function(struct ftrace_ops *ops);
226
227 extern void ftrace_stub(unsigned long a0, unsigned long a1,
228 struct ftrace_ops *op, struct pt_regs *regs);
229
230 #else /* !CONFIG_FUNCTION_TRACER */
231 /*
232 * (un)register_ftrace_function must be a macro since the ops parameter
233 * must not be evaluated.
234 */
235 #define register_ftrace_function(ops) ({ 0; })
236 #define unregister_ftrace_function(ops) ({ 0; })
ftrace_kill(void)237 static inline void ftrace_kill(void) { }
ftrace_free_init_mem(void)238 static inline void ftrace_free_init_mem(void) { }
ftrace_free_mem(struct module * mod,void * start,void * end)239 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
240 #endif /* CONFIG_FUNCTION_TRACER */
241
242 #ifdef CONFIG_STACK_TRACER
243
244 #define STACK_TRACE_ENTRIES 500
245
246 struct stack_trace;
247
248 extern unsigned stack_trace_index[];
249 extern struct stack_trace stack_trace_max;
250 extern unsigned long stack_trace_max_size;
251 extern arch_spinlock_t stack_trace_max_lock;
252
253 extern int stack_tracer_enabled;
254 void stack_trace_print(void);
255 int
256 stack_trace_sysctl(struct ctl_table *table, int write,
257 void __user *buffer, size_t *lenp,
258 loff_t *ppos);
259
260 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
261 DECLARE_PER_CPU(int, disable_stack_tracer);
262
263 /**
264 * stack_tracer_disable - temporarily disable the stack tracer
265 *
266 * There's a few locations (namely in RCU) where stack tracing
267 * cannot be executed. This function is used to disable stack
268 * tracing during those critical sections.
269 *
270 * This function must be called with preemption or interrupts
271 * disabled and stack_tracer_enable() must be called shortly after
272 * while preemption or interrupts are still disabled.
273 */
stack_tracer_disable(void)274 static inline void stack_tracer_disable(void)
275 {
276 /* Preemption or interupts must be disabled */
277 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
278 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
279 this_cpu_inc(disable_stack_tracer);
280 }
281
282 /**
283 * stack_tracer_enable - re-enable the stack tracer
284 *
285 * After stack_tracer_disable() is called, stack_tracer_enable()
286 * must be called shortly afterward.
287 */
stack_tracer_enable(void)288 static inline void stack_tracer_enable(void)
289 {
290 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
291 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
292 this_cpu_dec(disable_stack_tracer);
293 }
294 #else
stack_tracer_disable(void)295 static inline void stack_tracer_disable(void) { }
stack_tracer_enable(void)296 static inline void stack_tracer_enable(void) { }
297 #endif
298
299 #ifdef CONFIG_DYNAMIC_FTRACE
300
301 int ftrace_arch_code_modify_prepare(void);
302 int ftrace_arch_code_modify_post_process(void);
303
304 struct dyn_ftrace;
305
306 enum ftrace_bug_type {
307 FTRACE_BUG_UNKNOWN,
308 FTRACE_BUG_INIT,
309 FTRACE_BUG_NOP,
310 FTRACE_BUG_CALL,
311 FTRACE_BUG_UPDATE,
312 };
313 extern enum ftrace_bug_type ftrace_bug_type;
314
315 /*
316 * Archs can set this to point to a variable that holds the value that was
317 * expected at the call site before calling ftrace_bug().
318 */
319 extern const void *ftrace_expected;
320
321 void ftrace_bug(int err, struct dyn_ftrace *rec);
322
323 struct seq_file;
324
325 extern int ftrace_text_reserved(const void *start, const void *end);
326
327 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
328
329 bool is_ftrace_trampoline(unsigned long addr);
330
331 /*
332 * The dyn_ftrace record's flags field is split into two parts.
333 * the first part which is '0-FTRACE_REF_MAX' is a counter of
334 * the number of callbacks that have registered the function that
335 * the dyn_ftrace descriptor represents.
336 *
337 * The second part is a mask:
338 * ENABLED - the function is being traced
339 * REGS - the record wants the function to save regs
340 * REGS_EN - the function is set up to save regs.
341 * IPMODIFY - the record allows for the IP address to be changed.
342 * DISABLED - the record is not ready to be touched yet
343 *
344 * When a new ftrace_ops is registered and wants a function to save
345 * pt_regs, the rec->flag REGS is set. When the function has been
346 * set up to save regs, the REG_EN flag is set. Once a function
347 * starts saving regs it will do so until all ftrace_ops are removed
348 * from tracing that function.
349 */
350 enum {
351 FTRACE_FL_ENABLED = (1UL << 31),
352 FTRACE_FL_REGS = (1UL << 30),
353 FTRACE_FL_REGS_EN = (1UL << 29),
354 FTRACE_FL_TRAMP = (1UL << 28),
355 FTRACE_FL_TRAMP_EN = (1UL << 27),
356 FTRACE_FL_IPMODIFY = (1UL << 26),
357 FTRACE_FL_DISABLED = (1UL << 25),
358 };
359
360 #define FTRACE_REF_MAX_SHIFT 25
361 #define FTRACE_FL_BITS 7
362 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1)
363 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
364 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
365
366 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK)
367
368 struct dyn_ftrace {
369 unsigned long ip; /* address of mcount call-site */
370 unsigned long flags;
371 struct dyn_arch_ftrace arch;
372 };
373
374 int ftrace_force_update(void);
375 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
376 int remove, int reset);
377 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
378 int len, int reset);
379 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
380 int len, int reset);
381 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
382 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
383 void ftrace_free_filter(struct ftrace_ops *ops);
384 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
385
386 enum {
387 FTRACE_UPDATE_CALLS = (1 << 0),
388 FTRACE_DISABLE_CALLS = (1 << 1),
389 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
390 FTRACE_START_FUNC_RET = (1 << 3),
391 FTRACE_STOP_FUNC_RET = (1 << 4),
392 };
393
394 /*
395 * The FTRACE_UPDATE_* enum is used to pass information back
396 * from the ftrace_update_record() and ftrace_test_record()
397 * functions. These are called by the code update routines
398 * to find out what is to be done for a given function.
399 *
400 * IGNORE - The function is already what we want it to be
401 * MAKE_CALL - Start tracing the function
402 * MODIFY_CALL - Stop saving regs for the function
403 * MAKE_NOP - Stop tracing the function
404 */
405 enum {
406 FTRACE_UPDATE_IGNORE,
407 FTRACE_UPDATE_MAKE_CALL,
408 FTRACE_UPDATE_MODIFY_CALL,
409 FTRACE_UPDATE_MAKE_NOP,
410 };
411
412 enum {
413 FTRACE_ITER_FILTER = (1 << 0),
414 FTRACE_ITER_NOTRACE = (1 << 1),
415 FTRACE_ITER_PRINTALL = (1 << 2),
416 FTRACE_ITER_DO_PROBES = (1 << 3),
417 FTRACE_ITER_PROBE = (1 << 4),
418 FTRACE_ITER_MOD = (1 << 5),
419 FTRACE_ITER_ENABLED = (1 << 6),
420 };
421
422 void arch_ftrace_update_code(int command);
423
424 struct ftrace_rec_iter;
425
426 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
427 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
428 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
429
430 #define for_ftrace_rec_iter(iter) \
431 for (iter = ftrace_rec_iter_start(); \
432 iter; \
433 iter = ftrace_rec_iter_next(iter))
434
435
436 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
437 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
438 void ftrace_run_stop_machine(int command);
439 unsigned long ftrace_location(unsigned long ip);
440 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
441 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
442 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
443
444 extern ftrace_func_t ftrace_trace_function;
445
446 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
447 struct inode *inode, struct file *file);
448 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
449 size_t cnt, loff_t *ppos);
450 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
451 size_t cnt, loff_t *ppos);
452 int ftrace_regex_release(struct inode *inode, struct file *file);
453
454 void __init
455 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
456
457 /* defined in arch */
458 extern int ftrace_ip_converted(unsigned long ip);
459 extern int ftrace_dyn_arch_init(void);
460 extern void ftrace_replace_code(int enable);
461 extern int ftrace_update_ftrace_func(ftrace_func_t func);
462 extern void ftrace_caller(void);
463 extern void ftrace_regs_caller(void);
464 extern void ftrace_call(void);
465 extern void ftrace_regs_call(void);
466 extern void mcount_call(void);
467
468 void ftrace_modify_all_code(int command);
469
470 #ifndef FTRACE_ADDR
471 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
472 #endif
473
474 #ifndef FTRACE_GRAPH_ADDR
475 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
476 #endif
477
478 #ifndef FTRACE_REGS_ADDR
479 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
480 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
481 #else
482 # define FTRACE_REGS_ADDR FTRACE_ADDR
483 #endif
484 #endif
485
486 /*
487 * If an arch would like functions that are only traced
488 * by the function graph tracer to jump directly to its own
489 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
490 * to be that address to jump to.
491 */
492 #ifndef FTRACE_GRAPH_TRAMP_ADDR
493 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
494 #endif
495
496 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
497 extern void ftrace_graph_caller(void);
498 extern int ftrace_enable_ftrace_graph_caller(void);
499 extern int ftrace_disable_ftrace_graph_caller(void);
500 #else
ftrace_enable_ftrace_graph_caller(void)501 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
ftrace_disable_ftrace_graph_caller(void)502 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
503 #endif
504
505 /**
506 * ftrace_make_nop - convert code into nop
507 * @mod: module structure if called by module load initialization
508 * @rec: the mcount call site record
509 * @addr: the address that the call site should be calling
510 *
511 * This is a very sensitive operation and great care needs
512 * to be taken by the arch. The operation should carefully
513 * read the location, check to see if what is read is indeed
514 * what we expect it to be, and then on success of the compare,
515 * it should write to the location.
516 *
517 * The code segment at @rec->ip should be a caller to @addr
518 *
519 * Return must be:
520 * 0 on success
521 * -EFAULT on error reading the location
522 * -EINVAL on a failed compare of the contents
523 * -EPERM on error writing to the location
524 * Any other value will be considered a failure.
525 */
526 extern int ftrace_make_nop(struct module *mod,
527 struct dyn_ftrace *rec, unsigned long addr);
528
529 /**
530 * ftrace_make_call - convert a nop call site into a call to addr
531 * @rec: the mcount call site record
532 * @addr: the address that the call site should call
533 *
534 * This is a very sensitive operation and great care needs
535 * to be taken by the arch. The operation should carefully
536 * read the location, check to see if what is read is indeed
537 * what we expect it to be, and then on success of the compare,
538 * it should write to the location.
539 *
540 * The code segment at @rec->ip should be a nop
541 *
542 * Return must be:
543 * 0 on success
544 * -EFAULT on error reading the location
545 * -EINVAL on a failed compare of the contents
546 * -EPERM on error writing to the location
547 * Any other value will be considered a failure.
548 */
549 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
550
551 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
552 /**
553 * ftrace_modify_call - convert from one addr to another (no nop)
554 * @rec: the mcount call site record
555 * @old_addr: the address expected to be currently called to
556 * @addr: the address to change to
557 *
558 * This is a very sensitive operation and great care needs
559 * to be taken by the arch. The operation should carefully
560 * read the location, check to see if what is read is indeed
561 * what we expect it to be, and then on success of the compare,
562 * it should write to the location.
563 *
564 * The code segment at @rec->ip should be a caller to @old_addr
565 *
566 * Return must be:
567 * 0 on success
568 * -EFAULT on error reading the location
569 * -EINVAL on a failed compare of the contents
570 * -EPERM on error writing to the location
571 * Any other value will be considered a failure.
572 */
573 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
574 unsigned long addr);
575 #else
576 /* Should never be called */
ftrace_modify_call(struct dyn_ftrace * rec,unsigned long old_addr,unsigned long addr)577 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
578 unsigned long addr)
579 {
580 return -EINVAL;
581 }
582 #endif
583
584 /* May be defined in arch */
585 extern int ftrace_arch_read_dyn_info(char *buf, int size);
586
587 extern int skip_trace(unsigned long ip);
588 extern void ftrace_module_init(struct module *mod);
589 extern void ftrace_module_enable(struct module *mod);
590 extern void ftrace_release_mod(struct module *mod);
591
592 extern void ftrace_disable_daemon(void);
593 extern void ftrace_enable_daemon(void);
594 #else /* CONFIG_DYNAMIC_FTRACE */
skip_trace(unsigned long ip)595 static inline int skip_trace(unsigned long ip) { return 0; }
ftrace_force_update(void)596 static inline int ftrace_force_update(void) { return 0; }
ftrace_disable_daemon(void)597 static inline void ftrace_disable_daemon(void) { }
ftrace_enable_daemon(void)598 static inline void ftrace_enable_daemon(void) { }
ftrace_module_init(struct module * mod)599 static inline void ftrace_module_init(struct module *mod) { }
ftrace_module_enable(struct module * mod)600 static inline void ftrace_module_enable(struct module *mod) { }
ftrace_release_mod(struct module * mod)601 static inline void ftrace_release_mod(struct module *mod) { }
ftrace_text_reserved(const void * start,const void * end)602 static inline int ftrace_text_reserved(const void *start, const void *end)
603 {
604 return 0;
605 }
ftrace_location(unsigned long ip)606 static inline unsigned long ftrace_location(unsigned long ip)
607 {
608 return 0;
609 }
610
611 /*
612 * Again users of functions that have ftrace_ops may not
613 * have them defined when ftrace is not enabled, but these
614 * functions may still be called. Use a macro instead of inline.
615 */
616 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
617 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
618 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
619 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
620 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
621 #define ftrace_free_filter(ops) do { } while (0)
622 #define ftrace_ops_set_global_filter(ops) do { } while (0)
623
ftrace_filter_write(struct file * file,const char __user * ubuf,size_t cnt,loff_t * ppos)624 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
625 size_t cnt, loff_t *ppos) { return -ENODEV; }
ftrace_notrace_write(struct file * file,const char __user * ubuf,size_t cnt,loff_t * ppos)626 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
627 size_t cnt, loff_t *ppos) { return -ENODEV; }
628 static inline int
ftrace_regex_release(struct inode * inode,struct file * file)629 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
630
is_ftrace_trampoline(unsigned long addr)631 static inline bool is_ftrace_trampoline(unsigned long addr)
632 {
633 return false;
634 }
635 #endif /* CONFIG_DYNAMIC_FTRACE */
636
637 /* totally disable ftrace - can not re-enable after this */
638 void ftrace_kill(void);
639
tracer_disable(void)640 static inline void tracer_disable(void)
641 {
642 #ifdef CONFIG_FUNCTION_TRACER
643 ftrace_enabled = 0;
644 #endif
645 }
646
647 /*
648 * Ftrace disable/restore without lock. Some synchronization mechanism
649 * must be used to prevent ftrace_enabled to be changed between
650 * disable/restore.
651 */
__ftrace_enabled_save(void)652 static inline int __ftrace_enabled_save(void)
653 {
654 #ifdef CONFIG_FUNCTION_TRACER
655 int saved_ftrace_enabled = ftrace_enabled;
656 ftrace_enabled = 0;
657 return saved_ftrace_enabled;
658 #else
659 return 0;
660 #endif
661 }
662
__ftrace_enabled_restore(int enabled)663 static inline void __ftrace_enabled_restore(int enabled)
664 {
665 #ifdef CONFIG_FUNCTION_TRACER
666 ftrace_enabled = enabled;
667 #endif
668 }
669
670 /* All archs should have this, but we define it for consistency */
671 #ifndef ftrace_return_address0
672 # define ftrace_return_address0 __builtin_return_address(0)
673 #endif
674
675 /* Archs may use other ways for ADDR1 and beyond */
676 #ifndef ftrace_return_address
677 # ifdef CONFIG_FRAME_POINTER
678 # define ftrace_return_address(n) __builtin_return_address(n)
679 # else
680 # define ftrace_return_address(n) 0UL
681 # endif
682 #endif
683
684 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
685 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
686 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
687 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
688 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
689 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
690 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
691
get_lock_parent_ip(void)692 static inline unsigned long get_lock_parent_ip(void)
693 {
694 unsigned long addr = CALLER_ADDR0;
695
696 if (!in_lock_functions(addr))
697 return addr;
698 addr = CALLER_ADDR1;
699 if (!in_lock_functions(addr))
700 return addr;
701 return CALLER_ADDR2;
702 }
703
704 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
705 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
706 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
707 #else
708 /*
709 * Use defines instead of static inlines because some arches will make code out
710 * of the CALLER_ADDR, when we really want these to be a real nop.
711 */
712 # define trace_preempt_on(a0, a1) do { } while (0)
713 # define trace_preempt_off(a0, a1) do { } while (0)
714 #endif
715
716 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
717 extern void ftrace_init(void);
718 #else
ftrace_init(void)719 static inline void ftrace_init(void) { }
720 #endif
721
722 /*
723 * Structure that defines an entry function trace.
724 * It's already packed but the attribute "packed" is needed
725 * to remove extra padding at the end.
726 */
727 struct ftrace_graph_ent {
728 unsigned long func; /* Current function */
729 int depth;
730 } __packed;
731
732 /*
733 * Structure that defines a return function trace.
734 * It's already packed but the attribute "packed" is needed
735 * to remove extra padding at the end.
736 */
737 struct ftrace_graph_ret {
738 unsigned long func; /* Current function */
739 /* Number of functions that overran the depth limit for current task */
740 unsigned long overrun;
741 unsigned long long calltime;
742 unsigned long long rettime;
743 int depth;
744 } __packed;
745
746 /* Type of the callback handlers for tracing function graph*/
747 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
748 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
749
750 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
751
752 /*
753 * Stack of return addresses for functions
754 * of a thread.
755 * Used in struct thread_info
756 */
757 struct ftrace_ret_stack {
758 unsigned long ret;
759 unsigned long func;
760 unsigned long long calltime;
761 #ifdef CONFIG_FUNCTION_PROFILER
762 unsigned long long subtime;
763 #endif
764 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
765 unsigned long fp;
766 #endif
767 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
768 unsigned long *retp;
769 #endif
770 };
771
772 /*
773 * Primary handler of a function return.
774 * It relays on ftrace_return_to_handler.
775 * Defined in entry_32/64.S
776 */
777 extern void return_to_handler(void);
778
779 extern int
780 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
781 unsigned long frame_pointer, unsigned long *retp);
782
783 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
784 unsigned long ret, unsigned long *retp);
785
786 /*
787 * Sometimes we don't want to trace a function with the function
788 * graph tracer but we want them to keep traced by the usual function
789 * tracer if the function graph tracer is not configured.
790 */
791 #define __notrace_funcgraph notrace
792
793 #define FTRACE_NOTRACE_DEPTH 65536
794 #define FTRACE_RETFUNC_DEPTH 50
795 #define FTRACE_RETSTACK_ALLOC_SIZE 32
796 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
797 trace_func_graph_ent_t entryfunc);
798
799 extern bool ftrace_graph_is_dead(void);
800 extern void ftrace_graph_stop(void);
801
802 /* The current handlers in use */
803 extern trace_func_graph_ret_t ftrace_graph_return;
804 extern trace_func_graph_ent_t ftrace_graph_entry;
805
806 extern void unregister_ftrace_graph(void);
807
808 extern void ftrace_graph_init_task(struct task_struct *t);
809 extern void ftrace_graph_exit_task(struct task_struct *t);
810 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
811
task_curr_ret_stack(struct task_struct * t)812 static inline int task_curr_ret_stack(struct task_struct *t)
813 {
814 return t->curr_ret_stack;
815 }
816
pause_graph_tracing(void)817 static inline void pause_graph_tracing(void)
818 {
819 atomic_inc(¤t->tracing_graph_pause);
820 }
821
unpause_graph_tracing(void)822 static inline void unpause_graph_tracing(void)
823 {
824 atomic_dec(¤t->tracing_graph_pause);
825 }
826 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
827
828 #define __notrace_funcgraph
829
ftrace_graph_init_task(struct task_struct * t)830 static inline void ftrace_graph_init_task(struct task_struct *t) { }
ftrace_graph_exit_task(struct task_struct * t)831 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
ftrace_graph_init_idle_task(struct task_struct * t,int cpu)832 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
833
register_ftrace_graph(trace_func_graph_ret_t retfunc,trace_func_graph_ent_t entryfunc)834 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
835 trace_func_graph_ent_t entryfunc)
836 {
837 return -1;
838 }
unregister_ftrace_graph(void)839 static inline void unregister_ftrace_graph(void) { }
840
task_curr_ret_stack(struct task_struct * tsk)841 static inline int task_curr_ret_stack(struct task_struct *tsk)
842 {
843 return -1;
844 }
845
846 static inline unsigned long
ftrace_graph_ret_addr(struct task_struct * task,int * idx,unsigned long ret,unsigned long * retp)847 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
848 unsigned long *retp)
849 {
850 return ret;
851 }
852
pause_graph_tracing(void)853 static inline void pause_graph_tracing(void) { }
unpause_graph_tracing(void)854 static inline void unpause_graph_tracing(void) { }
855 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
856
857 #ifdef CONFIG_TRACING
858
859 /* flags for current->trace */
860 enum {
861 TSK_TRACE_FL_TRACE_BIT = 0,
862 TSK_TRACE_FL_GRAPH_BIT = 1,
863 };
864 enum {
865 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
866 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
867 };
868
set_tsk_trace_trace(struct task_struct * tsk)869 static inline void set_tsk_trace_trace(struct task_struct *tsk)
870 {
871 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
872 }
873
clear_tsk_trace_trace(struct task_struct * tsk)874 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
875 {
876 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
877 }
878
test_tsk_trace_trace(struct task_struct * tsk)879 static inline int test_tsk_trace_trace(struct task_struct *tsk)
880 {
881 return tsk->trace & TSK_TRACE_FL_TRACE;
882 }
883
set_tsk_trace_graph(struct task_struct * tsk)884 static inline void set_tsk_trace_graph(struct task_struct *tsk)
885 {
886 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
887 }
888
clear_tsk_trace_graph(struct task_struct * tsk)889 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
890 {
891 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
892 }
893
test_tsk_trace_graph(struct task_struct * tsk)894 static inline int test_tsk_trace_graph(struct task_struct *tsk)
895 {
896 return tsk->trace & TSK_TRACE_FL_GRAPH;
897 }
898
899 enum ftrace_dump_mode;
900
901 extern enum ftrace_dump_mode ftrace_dump_on_oops;
902 extern int tracepoint_printk;
903
904 extern void disable_trace_on_warning(void);
905 extern int __disable_trace_on_warning;
906
907 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
908 void __user *buffer, size_t *lenp,
909 loff_t *ppos);
910
911 #else /* CONFIG_TRACING */
disable_trace_on_warning(void)912 static inline void disable_trace_on_warning(void) { }
913 #endif /* CONFIG_TRACING */
914
915 #ifdef CONFIG_FTRACE_SYSCALLS
916
917 unsigned long arch_syscall_addr(int nr);
918
919 #endif /* CONFIG_FTRACE_SYSCALLS */
920
921 #endif /* _LINUX_FTRACE_H */
922
