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
45void trace_init(void);
46void early_trace_init(void);
47#else
48static inline void trace_init(void) { }
49static inline void early_trace_init(void) { }
50#endif
51
52struct module;
53struct ftrace_hash;
54
55#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
56 defined(CONFIG_DYNAMIC_FTRACE)
57const char *
58ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
59 unsigned long *off, char **modname, char *sym);
60int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
61 char *type, char *name,
62 char *module_name, int *exported);
63#else
64static inline const char *
65ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
66 unsigned long *off, char **modname, char *sym)
67{
68 return NULL;
69}
70static 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
81extern int ftrace_enabled;
82extern int
83ftrace_enable_sysctl(struct ctl_table *table, int write,
84 void __user *buffer, size_t *lenp,
85 loff_t *ppos);
86
87struct ftrace_ops;
88
89typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
90 struct ftrace_ops *op, struct pt_regs *regs);
91
92ftrace_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 */
146enum {
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 */
167struct ftrace_ops_hash {
168 struct ftrace_hash __rcu *notrace_hash;
169 struct ftrace_hash __rcu *filter_hash;
170 struct mutex regex_lock;
171};
172
173void ftrace_free_init_mem(void);
174void ftrace_free_mem(struct module *mod, void *start, void *end);
175#else
176static inline void ftrace_free_init_mem(void) { }
177static 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 */
191struct 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 */
209enum 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 */
215extern 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 */
224int register_ftrace_function(struct ftrace_ops *ops);
225int unregister_ftrace_function(struct ftrace_ops *ops);
226
227extern 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; })
237static inline void ftrace_kill(void) { }
238static inline void ftrace_free_init_mem(void) { }
239static 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
246struct stack_trace;
247
248extern unsigned stack_trace_index[];
249extern struct stack_trace stack_trace_max;
250extern unsigned long stack_trace_max_size;
251extern arch_spinlock_t stack_trace_max_lock;
252
253extern int stack_tracer_enabled;
254void stack_trace_print(void);
255int
256stack_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! */
261DECLARE_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 */
274static 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 */
288static 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
295static inline void stack_tracer_disable(void) { }
296static inline void stack_tracer_enable(void) { }
297#endif
298
299#ifdef CONFIG_DYNAMIC_FTRACE
300
301int ftrace_arch_code_modify_prepare(void);
302int ftrace_arch_code_modify_post_process(void);
303
304struct dyn_ftrace;
305
306enum ftrace_bug_type {
307 FTRACE_BUG_UNKNOWN,
308 FTRACE_BUG_INIT,
309 FTRACE_BUG_NOP,
310 FTRACE_BUG_CALL,
311 FTRACE_BUG_UPDATE,
312};
313extern 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 */
319extern const void *ftrace_expected;
320
321void ftrace_bug(int err, struct dyn_ftrace *rec);
322
323struct seq_file;
324
325extern int ftrace_text_reserved(const void *start, const void *end);
326
327struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
328
329bool 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 */
350enum {
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
368struct dyn_ftrace {
369 unsigned long ip; /* address of mcount call-site */
370 unsigned long flags;
371 struct dyn_arch_ftrace arch;
372};
373
374int ftrace_force_update(void);
375int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
376 int remove, int reset);
377int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
378 int len, int reset);
379int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
380 int len, int reset);
381void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
382void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
383void ftrace_free_filter(struct ftrace_ops *ops);
384void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
385
386enum {
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 */
405enum {
406 FTRACE_UPDATE_IGNORE,
407 FTRACE_UPDATE_MAKE_CALL,
408 FTRACE_UPDATE_MODIFY_CALL,
409 FTRACE_UPDATE_MAKE_NOP,
410};
411
412enum {
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
422void arch_ftrace_update_code(int command);
423
424struct ftrace_rec_iter;
425
426struct ftrace_rec_iter *ftrace_rec_iter_start(void);
427struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
428struct 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
436int ftrace_update_record(struct dyn_ftrace *rec, int enable);
437int ftrace_test_record(struct dyn_ftrace *rec, int enable);
438void ftrace_run_stop_machine(int command);
439unsigned long ftrace_location(unsigned long ip);
440unsigned long ftrace_location_range(unsigned long start, unsigned long end);
441unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
442unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
443
444extern ftrace_func_t ftrace_trace_function;
445
446int ftrace_regex_open(struct ftrace_ops *ops, int flag,
447 struct inode *inode, struct file *file);
448ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
449 size_t cnt, loff_t *ppos);
450ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
451 size_t cnt, loff_t *ppos);
452int ftrace_regex_release(struct inode *inode, struct file *file);
453
454void __init
455ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
456
457/* defined in arch */
458extern int ftrace_ip_converted(unsigned long ip);
459extern int ftrace_dyn_arch_init(void);
460extern void ftrace_replace_code(int enable);
461extern int ftrace_update_ftrace_func(ftrace_func_t func);
462extern void ftrace_caller(void);
463extern void ftrace_regs_caller(void);
464extern void ftrace_call(void);
465extern void ftrace_regs_call(void);
466extern void mcount_call(void);
467
468void 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
497extern void ftrace_graph_caller(void);
498extern int ftrace_enable_ftrace_graph_caller(void);
499extern int ftrace_disable_ftrace_graph_caller(void);
500#else
501static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
502static 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 */
526extern 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 */
549extern 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 */
573extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
574 unsigned long addr);
575#else
576/* Should never be called */
577static 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 */
585extern int ftrace_arch_read_dyn_info(char *buf, int size);
586
587extern int skip_trace(unsigned long ip);
588extern void ftrace_module_init(struct module *mod);
589extern void ftrace_module_enable(struct module *mod);
590extern void ftrace_release_mod(struct module *mod);
591
592extern void ftrace_disable_daemon(void);
593extern void ftrace_enable_daemon(void);
594#else /* CONFIG_DYNAMIC_FTRACE */
595static inline int skip_trace(unsigned long ip) { return 0; }
596static inline int ftrace_force_update(void) { return 0; }
597static inline void ftrace_disable_daemon(void) { }
598static inline void ftrace_enable_daemon(void) { }
599static inline void ftrace_module_init(struct module *mod) { }
600static inline void ftrace_module_enable(struct module *mod) { }
601static inline void ftrace_release_mod(struct module *mod) { }
602static inline int ftrace_text_reserved(const void *start, const void *end)
603{
604 return 0;
605}
606static 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
624static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
625 size_t cnt, loff_t *ppos) { return -ENODEV; }
626static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
627 size_t cnt, loff_t *ppos) { return -ENODEV; }
628static inline int
629ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
630
631static 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 */
638void ftrace_kill(void);
639
640static 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 */
652static 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
663static 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
692static 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
717extern void ftrace_init(void);
718#else
719static 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 */
727struct 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 */
737struct 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*/
747typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
748typedef 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 */
757struct 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 */
777extern void return_to_handler(void);
778
779extern int
780ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
781 unsigned long frame_pointer, unsigned long *retp);
782
783unsigned 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
796extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
797 trace_func_graph_ent_t entryfunc);
798
799extern bool ftrace_graph_is_dead(void);
800extern void ftrace_graph_stop(void);
801
802/* The current handlers in use */
803extern trace_func_graph_ret_t ftrace_graph_return;
804extern trace_func_graph_ent_t ftrace_graph_entry;
805
806extern void unregister_ftrace_graph(void);
807
808extern void ftrace_graph_init_task(struct task_struct *t);
809extern void ftrace_graph_exit_task(struct task_struct *t);
810extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
811
812static inline int task_curr_ret_stack(struct task_struct *t)
813{
814 return t->curr_ret_stack;
815}
816
817static inline void pause_graph_tracing(void)
818{
819 atomic_inc(&current->tracing_graph_pause);
820}
821
822static inline void unpause_graph_tracing(void)
823{
824 atomic_dec(&current->tracing_graph_pause);
825}
826#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
827
828#define __notrace_funcgraph
829
830static inline void ftrace_graph_init_task(struct task_struct *t) { }
831static inline void ftrace_graph_exit_task(struct task_struct *t) { }
832static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
833
834static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
835 trace_func_graph_ent_t entryfunc)
836{
837 return -1;
838}
839static inline void unregister_ftrace_graph(void) { }
840
841static inline int task_curr_ret_stack(struct task_struct *tsk)
842{
843 return -1;
844}
845
846static inline unsigned long
847ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
848 unsigned long *retp)
849{
850 return ret;
851}
852
853static inline void pause_graph_tracing(void) { }
854static inline void unpause_graph_tracing(void) { }
855#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
856
857#ifdef CONFIG_TRACING
858
859/* flags for current->trace */
860enum {
861 TSK_TRACE_FL_TRACE_BIT = 0,
862 TSK_TRACE_FL_GRAPH_BIT = 1,
863};
864enum {
865 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
866 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
867};
868
869static inline void set_tsk_trace_trace(struct task_struct *tsk)
870{
871 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
872}
873
874static inline void clear_tsk_trace_trace(struct task_struct *tsk)
875{
876 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
877}
878
879static inline int test_tsk_trace_trace(struct task_struct *tsk)
880{
881 return tsk->trace & TSK_TRACE_FL_TRACE;
882}
883
884static inline void set_tsk_trace_graph(struct task_struct *tsk)
885{
886 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
887}
888
889static inline void clear_tsk_trace_graph(struct task_struct *tsk)
890{
891 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
892}
893
894static inline int test_tsk_trace_graph(struct task_struct *tsk)
895{
896 return tsk->trace & TSK_TRACE_FL_GRAPH;
897}
898
899enum ftrace_dump_mode;
900
901extern enum ftrace_dump_mode ftrace_dump_on_oops;
902extern int tracepoint_printk;
903
904extern void disable_trace_on_warning(void);
905extern int __disable_trace_on_warning;
906
907int 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 */
912static inline void disable_trace_on_warning(void) { }
913#endif /* CONFIG_TRACING */
914
915#ifdef CONFIG_FTRACE_SYSCALLS
916
917unsigned long arch_syscall_addr(int nr);
918
919#endif /* CONFIG_FTRACE_SYSCALLS */
920
921#endif /* _LINUX_FTRACE_H */
922