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 extern int stack_tracer_enabled;
245
246 int stack_trace_sysctl(struct ctl_table *table, int write,
247 void __user *buffer, size_t *lenp,
248 loff_t *ppos);
249
250 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
251 DECLARE_PER_CPU(int, disable_stack_tracer);
252
253 /**
254 * stack_tracer_disable - temporarily disable the stack tracer
255 *
256 * There's a few locations (namely in RCU) where stack tracing
257 * cannot be executed. This function is used to disable stack
258 * tracing during those critical sections.
259 *
260 * This function must be called with preemption or interrupts
261 * disabled and stack_tracer_enable() must be called shortly after
262 * while preemption or interrupts are still disabled.
263 */
stack_tracer_disable(void)264 static inline void stack_tracer_disable(void)
265 {
266 /* Preemption or interupts must be disabled */
267 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
268 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
269 this_cpu_inc(disable_stack_tracer);
270 }
271
272 /**
273 * stack_tracer_enable - re-enable the stack tracer
274 *
275 * After stack_tracer_disable() is called, stack_tracer_enable()
276 * must be called shortly afterward.
277 */
stack_tracer_enable(void)278 static inline void stack_tracer_enable(void)
279 {
280 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
281 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
282 this_cpu_dec(disable_stack_tracer);
283 }
284 #else
stack_tracer_disable(void)285 static inline void stack_tracer_disable(void) { }
stack_tracer_enable(void)286 static inline void stack_tracer_enable(void) { }
287 #endif
288
289 #ifdef CONFIG_DYNAMIC_FTRACE
290
291 int ftrace_arch_code_modify_prepare(void);
292 int ftrace_arch_code_modify_post_process(void);
293
294 struct dyn_ftrace;
295
296 enum ftrace_bug_type {
297 FTRACE_BUG_UNKNOWN,
298 FTRACE_BUG_INIT,
299 FTRACE_BUG_NOP,
300 FTRACE_BUG_CALL,
301 FTRACE_BUG_UPDATE,
302 };
303 extern enum ftrace_bug_type ftrace_bug_type;
304
305 /*
306 * Archs can set this to point to a variable that holds the value that was
307 * expected at the call site before calling ftrace_bug().
308 */
309 extern const void *ftrace_expected;
310
311 void ftrace_bug(int err, struct dyn_ftrace *rec);
312
313 struct seq_file;
314
315 extern int ftrace_text_reserved(const void *start, const void *end);
316
317 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
318
319 bool is_ftrace_trampoline(unsigned long addr);
320
321 /*
322 * The dyn_ftrace record's flags field is split into two parts.
323 * the first part which is '0-FTRACE_REF_MAX' is a counter of
324 * the number of callbacks that have registered the function that
325 * the dyn_ftrace descriptor represents.
326 *
327 * The second part is a mask:
328 * ENABLED - the function is being traced
329 * REGS - the record wants the function to save regs
330 * REGS_EN - the function is set up to save regs.
331 * IPMODIFY - the record allows for the IP address to be changed.
332 * DISABLED - the record is not ready to be touched yet
333 *
334 * When a new ftrace_ops is registered and wants a function to save
335 * pt_regs, the rec->flag REGS is set. When the function has been
336 * set up to save regs, the REG_EN flag is set. Once a function
337 * starts saving regs it will do so until all ftrace_ops are removed
338 * from tracing that function.
339 */
340 enum {
341 FTRACE_FL_ENABLED = (1UL << 31),
342 FTRACE_FL_REGS = (1UL << 30),
343 FTRACE_FL_REGS_EN = (1UL << 29),
344 FTRACE_FL_TRAMP = (1UL << 28),
345 FTRACE_FL_TRAMP_EN = (1UL << 27),
346 FTRACE_FL_IPMODIFY = (1UL << 26),
347 FTRACE_FL_DISABLED = (1UL << 25),
348 };
349
350 #define FTRACE_REF_MAX_SHIFT 25
351 #define FTRACE_FL_BITS 7
352 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1)
353 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
354 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
355
356 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK)
357
358 struct dyn_ftrace {
359 unsigned long ip; /* address of mcount call-site */
360 unsigned long flags;
361 struct dyn_arch_ftrace arch;
362 };
363
364 int ftrace_force_update(void);
365 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
366 int remove, int reset);
367 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
368 int len, int reset);
369 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
370 int len, int reset);
371 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
372 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
373 void ftrace_free_filter(struct ftrace_ops *ops);
374 void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
375
376 enum {
377 FTRACE_UPDATE_CALLS = (1 << 0),
378 FTRACE_DISABLE_CALLS = (1 << 1),
379 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
380 FTRACE_START_FUNC_RET = (1 << 3),
381 FTRACE_STOP_FUNC_RET = (1 << 4),
382 FTRACE_MAY_SLEEP = (1 << 5),
383 };
384
385 /*
386 * The FTRACE_UPDATE_* enum is used to pass information back
387 * from the ftrace_update_record() and ftrace_test_record()
388 * functions. These are called by the code update routines
389 * to find out what is to be done for a given function.
390 *
391 * IGNORE - The function is already what we want it to be
392 * MAKE_CALL - Start tracing the function
393 * MODIFY_CALL - Stop saving regs for the function
394 * MAKE_NOP - Stop tracing the function
395 */
396 enum {
397 FTRACE_UPDATE_IGNORE,
398 FTRACE_UPDATE_MAKE_CALL,
399 FTRACE_UPDATE_MODIFY_CALL,
400 FTRACE_UPDATE_MAKE_NOP,
401 };
402
403 enum {
404 FTRACE_ITER_FILTER = (1 << 0),
405 FTRACE_ITER_NOTRACE = (1 << 1),
406 FTRACE_ITER_PRINTALL = (1 << 2),
407 FTRACE_ITER_DO_PROBES = (1 << 3),
408 FTRACE_ITER_PROBE = (1 << 4),
409 FTRACE_ITER_MOD = (1 << 5),
410 FTRACE_ITER_ENABLED = (1 << 6),
411 };
412
413 void arch_ftrace_update_code(int command);
414 void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
415 void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
416 void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
417
418 struct ftrace_rec_iter;
419
420 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
421 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
422 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
423
424 #define for_ftrace_rec_iter(iter) \
425 for (iter = ftrace_rec_iter_start(); \
426 iter; \
427 iter = ftrace_rec_iter_next(iter))
428
429
430 int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
431 int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
432 void ftrace_run_stop_machine(int command);
433 unsigned long ftrace_location(unsigned long ip);
434 unsigned long ftrace_location_range(unsigned long start, unsigned long end);
435 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
436 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
437
438 extern ftrace_func_t ftrace_trace_function;
439
440 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
441 struct inode *inode, struct file *file);
442 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
443 size_t cnt, loff_t *ppos);
444 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
445 size_t cnt, loff_t *ppos);
446 int ftrace_regex_release(struct inode *inode, struct file *file);
447
448 void __init
449 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
450
451 /* defined in arch */
452 extern int ftrace_ip_converted(unsigned long ip);
453 extern int ftrace_dyn_arch_init(void);
454 extern void ftrace_replace_code(int enable);
455 extern int ftrace_update_ftrace_func(ftrace_func_t func);
456 extern void ftrace_caller(void);
457 extern void ftrace_regs_caller(void);
458 extern void ftrace_call(void);
459 extern void ftrace_regs_call(void);
460 extern void mcount_call(void);
461
462 void ftrace_modify_all_code(int command);
463
464 #ifndef FTRACE_ADDR
465 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
466 #endif
467
468 #ifndef FTRACE_GRAPH_ADDR
469 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
470 #endif
471
472 #ifndef FTRACE_REGS_ADDR
473 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
474 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
475 #else
476 # define FTRACE_REGS_ADDR FTRACE_ADDR
477 #endif
478 #endif
479
480 /*
481 * If an arch would like functions that are only traced
482 * by the function graph tracer to jump directly to its own
483 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
484 * to be that address to jump to.
485 */
486 #ifndef FTRACE_GRAPH_TRAMP_ADDR
487 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
488 #endif
489
490 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
491 extern void ftrace_graph_caller(void);
492 extern int ftrace_enable_ftrace_graph_caller(void);
493 extern int ftrace_disable_ftrace_graph_caller(void);
494 #else
ftrace_enable_ftrace_graph_caller(void)495 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
ftrace_disable_ftrace_graph_caller(void)496 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
497 #endif
498
499 /**
500 * ftrace_make_nop - convert code into nop
501 * @mod: module structure if called by module load initialization
502 * @rec: the mcount call site record
503 * @addr: the address that the call site should be calling
504 *
505 * This is a very sensitive operation and great care needs
506 * to be taken by the arch. The operation should carefully
507 * read the location, check to see if what is read is indeed
508 * what we expect it to be, and then on success of the compare,
509 * it should write to the location.
510 *
511 * The code segment at @rec->ip should be a caller to @addr
512 *
513 * Return must be:
514 * 0 on success
515 * -EFAULT on error reading the location
516 * -EINVAL on a failed compare of the contents
517 * -EPERM on error writing to the location
518 * Any other value will be considered a failure.
519 */
520 extern int ftrace_make_nop(struct module *mod,
521 struct dyn_ftrace *rec, unsigned long addr);
522
523 /**
524 * ftrace_make_call - convert a nop call site into a call to addr
525 * @rec: the mcount call site record
526 * @addr: the address that the call site should call
527 *
528 * This is a very sensitive operation and great care needs
529 * to be taken by the arch. The operation should carefully
530 * read the location, check to see if what is read is indeed
531 * what we expect it to be, and then on success of the compare,
532 * it should write to the location.
533 *
534 * The code segment at @rec->ip should be a nop
535 *
536 * Return must be:
537 * 0 on success
538 * -EFAULT on error reading the location
539 * -EINVAL on a failed compare of the contents
540 * -EPERM on error writing to the location
541 * Any other value will be considered a failure.
542 */
543 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
544
545 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
546 /**
547 * ftrace_modify_call - convert from one addr to another (no nop)
548 * @rec: the mcount call site record
549 * @old_addr: the address expected to be currently called to
550 * @addr: the address to change to
551 *
552 * This is a very sensitive operation and great care needs
553 * to be taken by the arch. The operation should carefully
554 * read the location, check to see if what is read is indeed
555 * what we expect it to be, and then on success of the compare,
556 * it should write to the location.
557 *
558 * The code segment at @rec->ip should be a caller to @old_addr
559 *
560 * Return must be:
561 * 0 on success
562 * -EFAULT on error reading the location
563 * -EINVAL on a failed compare of the contents
564 * -EPERM on error writing to the location
565 * Any other value will be considered a failure.
566 */
567 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
568 unsigned long addr);
569 #else
570 /* Should never be called */
ftrace_modify_call(struct dyn_ftrace * rec,unsigned long old_addr,unsigned long addr)571 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
572 unsigned long addr)
573 {
574 return -EINVAL;
575 }
576 #endif
577
578 /* May be defined in arch */
579 extern int ftrace_arch_read_dyn_info(char *buf, int size);
580
581 extern int skip_trace(unsigned long ip);
582 extern void ftrace_module_init(struct module *mod);
583 extern void ftrace_module_enable(struct module *mod);
584 extern void ftrace_release_mod(struct module *mod);
585
586 extern void ftrace_disable_daemon(void);
587 extern void ftrace_enable_daemon(void);
588 #else /* CONFIG_DYNAMIC_FTRACE */
skip_trace(unsigned long ip)589 static inline int skip_trace(unsigned long ip) { return 0; }
ftrace_force_update(void)590 static inline int ftrace_force_update(void) { return 0; }
ftrace_disable_daemon(void)591 static inline void ftrace_disable_daemon(void) { }
ftrace_enable_daemon(void)592 static inline void ftrace_enable_daemon(void) { }
ftrace_module_init(struct module * mod)593 static inline void ftrace_module_init(struct module *mod) { }
ftrace_module_enable(struct module * mod)594 static inline void ftrace_module_enable(struct module *mod) { }
ftrace_release_mod(struct module * mod)595 static inline void ftrace_release_mod(struct module *mod) { }
ftrace_text_reserved(const void * start,const void * end)596 static inline int ftrace_text_reserved(const void *start, const void *end)
597 {
598 return 0;
599 }
ftrace_location(unsigned long ip)600 static inline unsigned long ftrace_location(unsigned long ip)
601 {
602 return 0;
603 }
604
605 /*
606 * Again users of functions that have ftrace_ops may not
607 * have them defined when ftrace is not enabled, but these
608 * functions may still be called. Use a macro instead of inline.
609 */
610 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
611 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
612 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
613 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
614 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
615 #define ftrace_free_filter(ops) do { } while (0)
616 #define ftrace_ops_set_global_filter(ops) do { } while (0)
617
ftrace_filter_write(struct file * file,const char __user * ubuf,size_t cnt,loff_t * ppos)618 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
619 size_t cnt, loff_t *ppos) { return -ENODEV; }
ftrace_notrace_write(struct file * file,const char __user * ubuf,size_t cnt,loff_t * ppos)620 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
621 size_t cnt, loff_t *ppos) { return -ENODEV; }
622 static inline int
ftrace_regex_release(struct inode * inode,struct file * file)623 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
624
is_ftrace_trampoline(unsigned long addr)625 static inline bool is_ftrace_trampoline(unsigned long addr)
626 {
627 return false;
628 }
629 #endif /* CONFIG_DYNAMIC_FTRACE */
630
631 /* totally disable ftrace - can not re-enable after this */
632 void ftrace_kill(void);
633
tracer_disable(void)634 static inline void tracer_disable(void)
635 {
636 #ifdef CONFIG_FUNCTION_TRACER
637 ftrace_enabled = 0;
638 #endif
639 }
640
641 /*
642 * Ftrace disable/restore without lock. Some synchronization mechanism
643 * must be used to prevent ftrace_enabled to be changed between
644 * disable/restore.
645 */
__ftrace_enabled_save(void)646 static inline int __ftrace_enabled_save(void)
647 {
648 #ifdef CONFIG_FUNCTION_TRACER
649 int saved_ftrace_enabled = ftrace_enabled;
650 ftrace_enabled = 0;
651 return saved_ftrace_enabled;
652 #else
653 return 0;
654 #endif
655 }
656
__ftrace_enabled_restore(int enabled)657 static inline void __ftrace_enabled_restore(int enabled)
658 {
659 #ifdef CONFIG_FUNCTION_TRACER
660 ftrace_enabled = enabled;
661 #endif
662 }
663
664 /* All archs should have this, but we define it for consistency */
665 #ifndef ftrace_return_address0
666 # define ftrace_return_address0 __builtin_return_address(0)
667 #endif
668
669 /* Archs may use other ways for ADDR1 and beyond */
670 #ifndef ftrace_return_address
671 # ifdef CONFIG_FRAME_POINTER
672 # define ftrace_return_address(n) __builtin_return_address(n)
673 # else
674 # define ftrace_return_address(n) 0UL
675 # endif
676 #endif
677
678 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
679 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
680 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
681 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
682 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
683 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
684 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
685
get_lock_parent_ip(void)686 static inline unsigned long get_lock_parent_ip(void)
687 {
688 unsigned long addr = CALLER_ADDR0;
689
690 if (!in_lock_functions(addr))
691 return addr;
692 addr = CALLER_ADDR1;
693 if (!in_lock_functions(addr))
694 return addr;
695 return CALLER_ADDR2;
696 }
697
698 #ifdef CONFIG_TRACE_PREEMPT_TOGGLE
699 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
700 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
701 #else
702 /*
703 * Use defines instead of static inlines because some arches will make code out
704 * of the CALLER_ADDR, when we really want these to be a real nop.
705 */
706 # define trace_preempt_on(a0, a1) do { } while (0)
707 # define trace_preempt_off(a0, a1) do { } while (0)
708 #endif
709
710 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
711 extern void ftrace_init(void);
712 #else
ftrace_init(void)713 static inline void ftrace_init(void) { }
714 #endif
715
716 /*
717 * Structure that defines an entry function trace.
718 * It's already packed but the attribute "packed" is needed
719 * to remove extra padding at the end.
720 */
721 struct ftrace_graph_ent {
722 unsigned long func; /* Current function */
723 int depth;
724 } __packed;
725
726 /*
727 * Structure that defines a return function trace.
728 * It's already packed but the attribute "packed" is needed
729 * to remove extra padding at the end.
730 */
731 struct ftrace_graph_ret {
732 unsigned long func; /* Current function */
733 /* Number of functions that overran the depth limit for current task */
734 unsigned long overrun;
735 unsigned long long calltime;
736 unsigned long long rettime;
737 int depth;
738 } __packed;
739
740 /* Type of the callback handlers for tracing function graph*/
741 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
742 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
743
744 extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
745
746 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
747
748 struct fgraph_ops {
749 trace_func_graph_ent_t entryfunc;
750 trace_func_graph_ret_t retfunc;
751 };
752
753 /*
754 * Stack of return addresses for functions
755 * of a thread.
756 * Used in struct thread_info
757 */
758 struct ftrace_ret_stack {
759 unsigned long ret;
760 unsigned long func;
761 unsigned long long calltime;
762 #ifdef CONFIG_FUNCTION_PROFILER
763 unsigned long long subtime;
764 #endif
765 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
766 unsigned long fp;
767 #endif
768 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
769 unsigned long *retp;
770 #endif
771 };
772
773 /*
774 * Primary handler of a function return.
775 * It relays on ftrace_return_to_handler.
776 * Defined in entry_32/64.S
777 */
778 extern void return_to_handler(void);
779
780 extern int
781 function_graph_enter(unsigned long ret, unsigned long func,
782 unsigned long frame_pointer, unsigned long *retp);
783
784 struct ftrace_ret_stack *
785 ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
786
787 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
788 unsigned long ret, unsigned long *retp);
789
790 /*
791 * Sometimes we don't want to trace a function with the function
792 * graph tracer but we want them to keep traced by the usual function
793 * tracer if the function graph tracer is not configured.
794 */
795 #define __notrace_funcgraph notrace
796
797 #define FTRACE_RETFUNC_DEPTH 50
798 #define FTRACE_RETSTACK_ALLOC_SIZE 32
799
800 extern int register_ftrace_graph(struct fgraph_ops *ops);
801 extern void unregister_ftrace_graph(struct fgraph_ops *ops);
802
803 extern bool ftrace_graph_is_dead(void);
804 extern void ftrace_graph_stop(void);
805
806 /* The current handlers in use */
807 extern trace_func_graph_ret_t ftrace_graph_return;
808 extern trace_func_graph_ent_t ftrace_graph_entry;
809
810 extern void ftrace_graph_init_task(struct task_struct *t);
811 extern void ftrace_graph_exit_task(struct task_struct *t);
812 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
813
pause_graph_tracing(void)814 static inline void pause_graph_tracing(void)
815 {
816 atomic_inc(¤t->tracing_graph_pause);
817 }
818
unpause_graph_tracing(void)819 static inline void unpause_graph_tracing(void)
820 {
821 atomic_dec(¤t->tracing_graph_pause);
822 }
823 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
824
825 #define __notrace_funcgraph
826
ftrace_graph_init_task(struct task_struct * t)827 static inline void ftrace_graph_init_task(struct task_struct *t) { }
ftrace_graph_exit_task(struct task_struct * t)828 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
ftrace_graph_init_idle_task(struct task_struct * t,int cpu)829 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
830
831 /* Define as macros as fgraph_ops may not be defined */
832 #define register_ftrace_graph(ops) ({ -1; })
833 #define unregister_ftrace_graph(ops) do { } while (0)
834
835 static inline unsigned long
ftrace_graph_ret_addr(struct task_struct * task,int * idx,unsigned long ret,unsigned long * retp)836 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
837 unsigned long *retp)
838 {
839 return ret;
840 }
841
pause_graph_tracing(void)842 static inline void pause_graph_tracing(void) { }
unpause_graph_tracing(void)843 static inline void unpause_graph_tracing(void) { }
844 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
845
846 #ifdef CONFIG_TRACING
847
848 /* flags for current->trace */
849 enum {
850 TSK_TRACE_FL_TRACE_BIT = 0,
851 TSK_TRACE_FL_GRAPH_BIT = 1,
852 };
853 enum {
854 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
855 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
856 };
857
set_tsk_trace_trace(struct task_struct * tsk)858 static inline void set_tsk_trace_trace(struct task_struct *tsk)
859 {
860 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
861 }
862
clear_tsk_trace_trace(struct task_struct * tsk)863 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
864 {
865 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
866 }
867
test_tsk_trace_trace(struct task_struct * tsk)868 static inline int test_tsk_trace_trace(struct task_struct *tsk)
869 {
870 return tsk->trace & TSK_TRACE_FL_TRACE;
871 }
872
set_tsk_trace_graph(struct task_struct * tsk)873 static inline void set_tsk_trace_graph(struct task_struct *tsk)
874 {
875 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
876 }
877
clear_tsk_trace_graph(struct task_struct * tsk)878 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
879 {
880 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
881 }
882
test_tsk_trace_graph(struct task_struct * tsk)883 static inline int test_tsk_trace_graph(struct task_struct *tsk)
884 {
885 return tsk->trace & TSK_TRACE_FL_GRAPH;
886 }
887
888 enum ftrace_dump_mode;
889
890 extern enum ftrace_dump_mode ftrace_dump_on_oops;
891 extern int tracepoint_printk;
892
893 extern void disable_trace_on_warning(void);
894 extern int __disable_trace_on_warning;
895
896 int tracepoint_printk_sysctl(struct ctl_table *table, int write,
897 void __user *buffer, size_t *lenp,
898 loff_t *ppos);
899
900 #else /* CONFIG_TRACING */
disable_trace_on_warning(void)901 static inline void disable_trace_on_warning(void) { }
902 #endif /* CONFIG_TRACING */
903
904 #ifdef CONFIG_FTRACE_SYSCALLS
905
906 unsigned long arch_syscall_addr(int nr);
907
908 #endif /* CONFIG_FTRACE_SYSCALLS */
909
910 #endif /* _LINUX_FTRACE_H */
911
