Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Ftrace header. For implementation details beyond the random comments
4 * scattered below, see: Documentation/trace/ftrace-design.rst
5 */
6
7#ifndef _LINUX_FTRACE_H
8#define _LINUX_FTRACE_H
9
10#include <linux/trace_recursion.h>
11#include <linux/trace_clock.h>
12#include <linux/jump_label.h>
13#include <linux/kallsyms.h>
14#include <linux/linkage.h>
15#include <linux/bitops.h>
16#include <linux/ptrace.h>
17#include <linux/ktime.h>
18#include <linux/sched.h>
19#include <linux/types.h>
20#include <linux/init.h>
21#include <linux/fs.h>
22
23#include <asm/ftrace.h>
24
25/*
26 * If the arch supports passing the variable contents of
27 * function_trace_op as the third parameter back from the
28 * mcount call, then the arch should define this as 1.
29 */
30#ifndef ARCH_SUPPORTS_FTRACE_OPS
31#define ARCH_SUPPORTS_FTRACE_OPS 0
32#endif
33
34#ifdef CONFIG_TRACER_SNAPSHOT
35extern void ftrace_boot_snapshot(void);
36#else
37static inline void ftrace_boot_snapshot(void) { }
38#endif
39
40struct ftrace_ops;
41struct ftrace_regs;
42struct dyn_ftrace;
43
44char *arch_ftrace_match_adjust(char *str, const char *search);
45
46#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FREGS
47unsigned long ftrace_return_to_handler(struct ftrace_regs *fregs);
48#else
49unsigned long ftrace_return_to_handler(unsigned long frame_pointer);
50#endif
51
52#ifdef CONFIG_FUNCTION_TRACER
53/*
54 * If the arch's mcount caller does not support all of ftrace's
55 * features, then it must call an indirect function that
56 * does. Or at least does enough to prevent any unwelcome side effects.
57 *
58 * Also define the function prototype that these architectures use
59 * to call the ftrace_ops_list_func().
60 */
61#if !ARCH_SUPPORTS_FTRACE_OPS
62# define FTRACE_FORCE_LIST_FUNC 1
63void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
64#else
65# define FTRACE_FORCE_LIST_FUNC 0
66void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
67 struct ftrace_ops *op, struct ftrace_regs *fregs);
68#endif
69extern const struct ftrace_ops ftrace_nop_ops;
70extern const struct ftrace_ops ftrace_list_ops;
71struct ftrace_ops *ftrace_find_unique_ops(struct dyn_ftrace *rec);
72#endif /* CONFIG_FUNCTION_TRACER */
73
74/* Main tracing buffer and events set up */
75#ifdef CONFIG_TRACING
76void trace_init(void);
77void early_trace_init(void);
78#else
79static inline void trace_init(void) { }
80static inline void early_trace_init(void) { }
81#endif
82
83struct module;
84struct ftrace_hash;
85struct ftrace_func_entry;
86
87#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
88 defined(CONFIG_DYNAMIC_FTRACE)
89int
90ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
91 unsigned long *off, char **modname,
92 const unsigned char **modbuildid, char *sym);
93#else
94static inline int
95ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
96 unsigned long *off, char **modname,
97 const unsigned char **modbuildid, char *sym)
98{
99 return 0;
100}
101#endif
102
103#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
104int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
105 char *type, char *name,
106 char *module_name, int *exported);
107#else
108static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
109 char *type, char *name,
110 char *module_name, int *exported)
111{
112 return -1;
113}
114#endif
115
116#ifdef CONFIG_FUNCTION_TRACER
117
118#include <linux/ftrace_regs.h>
119
120extern int ftrace_enabled;
121
122/**
123 * ftrace_regs - ftrace partial/optimal register set
124 *
125 * ftrace_regs represents a group of registers which is used at the
126 * function entry and exit. There are three types of registers.
127 *
128 * - Registers for passing the parameters to callee, including the stack
129 * pointer. (e.g. rcx, rdx, rdi, rsi, r8, r9 and rsp on x86_64)
130 * - Registers for passing the return values to caller.
131 * (e.g. rax and rdx on x86_64)
132 * - Registers for hooking the function call and return including the
133 * frame pointer (the frame pointer is architecture/config dependent)
134 * (e.g. rip, rbp and rsp for x86_64)
135 *
136 * Also, architecture dependent fields can be used for internal process.
137 * (e.g. orig_ax on x86_64)
138 *
139 * Basically, ftrace_regs stores the registers related to the context.
140 * On function entry, registers for function parameters and hooking the
141 * function call are stored, and on function exit, registers for function
142 * return value and frame pointers are stored.
143 *
144 * And also, it dpends on the context that which registers are restored
145 * from the ftrace_regs.
146 * On the function entry, those registers will be restored except for
147 * the stack pointer, so that user can change the function parameters
148 * and instruction pointer (e.g. live patching.)
149 * On the function exit, only registers which is used for return values
150 * are restored.
151 *
152 * NOTE: user *must not* access regs directly, only do it via APIs, because
153 * the member can be changed according to the architecture.
154 * This is why the structure is empty here, so that nothing accesses
155 * the ftrace_regs directly.
156 */
157struct ftrace_regs {
158 /* Nothing to see here, use the accessor functions! */
159};
160
161#define ftrace_regs_size() sizeof(struct __arch_ftrace_regs)
162
163#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
164/*
165 * Architectures that define HAVE_DYNAMIC_FTRACE_WITH_ARGS must define their own
166 * arch_ftrace_get_regs() where it only returns pt_regs *if* it is fully
167 * populated. It should return NULL otherwise.
168 */
169static inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
170{
171 return &arch_ftrace_regs(fregs)->regs;
172}
173
174/*
175 * ftrace_regs_set_instruction_pointer() is to be defined by the architecture
176 * if to allow setting of the instruction pointer from the ftrace_regs when
177 * HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports live kernel patching.
178 */
179#define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0)
180#endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
181
182#ifdef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS
183
184static_assert(sizeof(struct pt_regs) == ftrace_regs_size());
185
186#endif /* CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS */
187
188static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
189{
190 if (!fregs)
191 return NULL;
192
193 return arch_ftrace_get_regs(fregs);
194}
195
196#if !defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS) || \
197 defined(CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS)
198
199#ifndef arch_ftrace_partial_regs
200#define arch_ftrace_partial_regs(regs) do {} while (0)
201#endif
202
203static __always_inline struct pt_regs *
204ftrace_partial_regs(struct ftrace_regs *fregs, struct pt_regs *regs)
205{
206 /*
207 * If CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS=y, ftrace_regs memory
208 * layout is including pt_regs. So always returns that address.
209 * Since arch_ftrace_get_regs() will check some members and may return
210 * NULL, we can not use it.
211 */
212 regs = &arch_ftrace_regs(fregs)->regs;
213
214 /* Allow arch specific updates to regs. */
215 arch_ftrace_partial_regs(regs);
216 return regs;
217}
218
219#endif /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS || CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS */
220
221#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
222
223/*
224 * Please define arch dependent pt_regs which compatible to the
225 * perf_arch_fetch_caller_regs() but based on ftrace_regs.
226 * This requires
227 * - user_mode(_regs) returns false (always kernel mode).
228 * - able to use the _regs for stack trace.
229 */
230#ifndef arch_ftrace_fill_perf_regs
231/* As same as perf_arch_fetch_caller_regs(), do nothing by default */
232#define arch_ftrace_fill_perf_regs(fregs, _regs) do {} while (0)
233#endif
234
235static __always_inline struct pt_regs *
236ftrace_fill_perf_regs(struct ftrace_regs *fregs, struct pt_regs *regs)
237{
238 arch_ftrace_fill_perf_regs(fregs, regs);
239 return regs;
240}
241
242#else /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
243
244static __always_inline struct pt_regs *
245ftrace_fill_perf_regs(struct ftrace_regs *fregs, struct pt_regs *regs)
246{
247 return &arch_ftrace_regs(fregs)->regs;
248}
249
250#endif
251
252/*
253 * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs.
254 * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs.
255 */
256static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs)
257{
258 if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS))
259 return true;
260
261 return ftrace_get_regs(fregs) != NULL;
262}
263
264#ifdef CONFIG_HAVE_REGS_AND_STACK_ACCESS_API
265static __always_inline unsigned long
266ftrace_regs_get_kernel_stack_nth(struct ftrace_regs *fregs, unsigned int nth)
267{
268 unsigned long *stackp;
269
270 stackp = (unsigned long *)ftrace_regs_get_stack_pointer(fregs);
271 if (((unsigned long)(stackp + nth) & ~(THREAD_SIZE - 1)) ==
272 ((unsigned long)stackp & ~(THREAD_SIZE - 1)))
273 return *(stackp + nth);
274
275 return 0;
276}
277#else /* !CONFIG_HAVE_REGS_AND_STACK_ACCESS_API */
278#define ftrace_regs_get_kernel_stack_nth(fregs, nth) (0L)
279#endif /* CONFIG_HAVE_REGS_AND_STACK_ACCESS_API */
280
281typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
282 struct ftrace_ops *op, struct ftrace_regs *fregs);
283
284ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
285
286/*
287 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
288 * set in the flags member.
289 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and
290 * IPMODIFY are a kind of attribute flags which can be set only before
291 * registering the ftrace_ops, and can not be modified while registered.
292 * Changing those attribute flags after registering ftrace_ops will
293 * cause unexpected results.
294 *
295 * ENABLED - set/unset when ftrace_ops is registered/unregistered
296 * DYNAMIC - set when ftrace_ops is registered to denote dynamically
297 * allocated ftrace_ops which need special care
298 * SAVE_REGS - The ftrace_ops wants regs saved at each function called
299 * and passed to the callback. If this flag is set, but the
300 * architecture does not support passing regs
301 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
302 * ftrace_ops will fail to register, unless the next flag
303 * is set.
304 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
305 * handler can handle an arch that does not save regs
306 * (the handler tests if regs == NULL), then it can set
307 * this flag instead. It will not fail registering the ftrace_ops
308 * but, the regs field will be NULL if the arch does not support
309 * passing regs to the handler.
310 * Note, if this flag is set, the SAVE_REGS flag will automatically
311 * get set upon registering the ftrace_ops, if the arch supports it.
312 * RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure
313 * that the call back needs recursion protection. If it does
314 * not set this, then the ftrace infrastructure will assume
315 * that the callback can handle recursion on its own.
316 * STUB - The ftrace_ops is just a place holder.
317 * INITIALIZED - The ftrace_ops has already been initialized (first use time
318 * register_ftrace_function() is called, it will initialized the ops)
319 * DELETED - The ops are being deleted, do not let them be registered again.
320 * ADDING - The ops is in the process of being added.
321 * REMOVING - The ops is in the process of being removed.
322 * MODIFYING - The ops is in the process of changing its filter functions.
323 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
324 * The arch specific code sets this flag when it allocated a
325 * trampoline. This lets the arch know that it can update the
326 * trampoline in case the callback function changes.
327 * The ftrace_ops trampoline can be set by the ftrace users, and
328 * in such cases the arch must not modify it. Only the arch ftrace
329 * core code should set this flag.
330 * IPMODIFY - The ops can modify the IP register. This can only be set with
331 * SAVE_REGS. If another ops with this flag set is already registered
332 * for any of the functions that this ops will be registered for, then
333 * this ops will fail to register or set_filter_ip.
334 * PID - Is affected by set_ftrace_pid (allows filtering on those pids)
335 * RCU - Set when the ops can only be called when RCU is watching.
336 * TRACE_ARRAY - The ops->private points to a trace_array descriptor.
337 * PERMANENT - Set when the ops is permanent and should not be affected by
338 * ftrace_enabled.
339 * DIRECT - Used by the direct ftrace_ops helper for direct functions
340 * (internal ftrace only, should not be used by others)
341 * SUBOP - Is controlled by another op in field managed.
342 * GRAPH - Is a component of the fgraph_ops structure
343 */
344enum {
345 FTRACE_OPS_FL_ENABLED = BIT(0),
346 FTRACE_OPS_FL_DYNAMIC = BIT(1),
347 FTRACE_OPS_FL_SAVE_REGS = BIT(2),
348 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3),
349 FTRACE_OPS_FL_RECURSION = BIT(4),
350 FTRACE_OPS_FL_STUB = BIT(5),
351 FTRACE_OPS_FL_INITIALIZED = BIT(6),
352 FTRACE_OPS_FL_DELETED = BIT(7),
353 FTRACE_OPS_FL_ADDING = BIT(8),
354 FTRACE_OPS_FL_REMOVING = BIT(9),
355 FTRACE_OPS_FL_MODIFYING = BIT(10),
356 FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11),
357 FTRACE_OPS_FL_IPMODIFY = BIT(12),
358 FTRACE_OPS_FL_PID = BIT(13),
359 FTRACE_OPS_FL_RCU = BIT(14),
360 FTRACE_OPS_FL_TRACE_ARRAY = BIT(15),
361 FTRACE_OPS_FL_PERMANENT = BIT(16),
362 FTRACE_OPS_FL_DIRECT = BIT(17),
363 FTRACE_OPS_FL_SUBOP = BIT(18),
364 FTRACE_OPS_FL_GRAPH = BIT(19),
365};
366
367#ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
368#define FTRACE_OPS_FL_SAVE_ARGS FTRACE_OPS_FL_SAVE_REGS
369#else
370#define FTRACE_OPS_FL_SAVE_ARGS 0
371#endif
372
373/*
374 * FTRACE_OPS_CMD_* commands allow the ftrace core logic to request changes
375 * to a ftrace_ops. Note, the requests may fail.
376 *
377 * ENABLE_SHARE_IPMODIFY_SELF - enable a DIRECT ops to work on the same
378 * function as an ops with IPMODIFY. Called
379 * when the DIRECT ops is being registered.
380 * This is called with both direct_mutex and
381 * ftrace_lock are locked.
382 *
383 * ENABLE_SHARE_IPMODIFY_PEER - enable a DIRECT ops to work on the same
384 * function as an ops with IPMODIFY. Called
385 * when the other ops (the one with IPMODIFY)
386 * is being registered.
387 * This is called with direct_mutex locked.
388 *
389 * DISABLE_SHARE_IPMODIFY_PEER - disable a DIRECT ops to work on the same
390 * function as an ops with IPMODIFY. Called
391 * when the other ops (the one with IPMODIFY)
392 * is being unregistered.
393 * This is called with direct_mutex locked.
394 */
395enum ftrace_ops_cmd {
396 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF,
397 FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER,
398 FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER,
399};
400
401/*
402 * For most ftrace_ops_cmd,
403 * Returns:
404 * 0 - Success.
405 * Negative on failure. The return value is dependent on the
406 * callback.
407 */
408typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, unsigned long ip, enum ftrace_ops_cmd cmd);
409
410#ifdef CONFIG_DYNAMIC_FTRACE
411
412#define FTRACE_HASH_DEFAULT_BITS 10
413
414struct ftrace_hash *alloc_ftrace_hash(int size_bits);
415void free_ftrace_hash(struct ftrace_hash *hash);
416struct ftrace_func_entry *add_ftrace_hash_entry_direct(struct ftrace_hash *hash,
417 unsigned long ip, unsigned long direct);
418
419/* The hash used to know what functions callbacks trace */
420struct ftrace_ops_hash {
421 struct ftrace_hash __rcu *notrace_hash;
422 struct ftrace_hash __rcu *filter_hash;
423 struct mutex regex_lock;
424};
425
426void ftrace_free_init_mem(void);
427void ftrace_free_mem(struct module *mod, void *start, void *end);
428#else
429static inline void ftrace_free_init_mem(void)
430{
431 ftrace_boot_snapshot();
432}
433static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
434#endif
435
436/*
437 * Note, ftrace_ops can be referenced outside of RCU protection, unless
438 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel
439 * core data, the unregistering of it will perform a scheduling on all CPUs
440 * to make sure that there are no more users. Depending on the load of the
441 * system that may take a bit of time.
442 *
443 * Any private data added must also take care not to be freed and if private
444 * data is added to a ftrace_ops that is in core code, the user of the
445 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
446 */
447struct ftrace_ops {
448 ftrace_func_t func;
449 struct ftrace_ops __rcu *next;
450 unsigned long flags;
451 void *private;
452 ftrace_func_t saved_func;
453#ifdef CONFIG_DYNAMIC_FTRACE
454 struct ftrace_ops_hash local_hash;
455 struct ftrace_ops_hash *func_hash;
456 struct ftrace_ops_hash old_hash;
457 unsigned long trampoline;
458 unsigned long trampoline_size;
459 struct list_head list;
460 struct list_head subop_list;
461 ftrace_ops_func_t ops_func;
462 struct ftrace_ops *managed;
463#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
464 unsigned long direct_call;
465#endif
466#endif
467};
468
469extern struct ftrace_ops __rcu *ftrace_ops_list;
470extern struct ftrace_ops ftrace_list_end;
471
472/*
473 * Traverse the ftrace_ops_list, invoking all entries. The reason that we
474 * can use rcu_dereference_raw_check() is that elements removed from this list
475 * are simply leaked, so there is no need to interact with a grace-period
476 * mechanism. The rcu_dereference_raw_check() calls are needed to handle
477 * concurrent insertions into the ftrace_ops_list.
478 *
479 * Silly Alpha and silly pointer-speculation compiler optimizations!
480 */
481#define do_for_each_ftrace_op(op, list) \
482 op = rcu_dereference_raw_check(list); \
483 do
484
485/*
486 * Optimized for just a single item in the list (as that is the normal case).
487 */
488#define while_for_each_ftrace_op(op) \
489 while (likely(op = rcu_dereference_raw_check((op)->next)) && \
490 unlikely((op) != &ftrace_list_end))
491
492/*
493 * Type of the current tracing.
494 */
495enum ftrace_tracing_type_t {
496 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
497 FTRACE_TYPE_RETURN, /* Hook the return of the function */
498};
499
500/* Current tracing type, default is FTRACE_TYPE_ENTER */
501extern enum ftrace_tracing_type_t ftrace_tracing_type;
502
503/*
504 * The ftrace_ops must be a static and should also
505 * be read_mostly. These functions do modify read_mostly variables
506 * so use them sparely. Never free an ftrace_op or modify the
507 * next pointer after it has been registered. Even after unregistering
508 * it, the next pointer may still be used internally.
509 */
510int register_ftrace_function(struct ftrace_ops *ops);
511int unregister_ftrace_function(struct ftrace_ops *ops);
512
513extern void ftrace_stub(unsigned long a0, unsigned long a1,
514 struct ftrace_ops *op, struct ftrace_regs *fregs);
515
516
517int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs);
518#else /* !CONFIG_FUNCTION_TRACER */
519/*
520 * (un)register_ftrace_function must be a macro since the ops parameter
521 * must not be evaluated.
522 */
523#define register_ftrace_function(ops) ({ 0; })
524#define unregister_ftrace_function(ops) ({ 0; })
525static inline void ftrace_kill(void) { }
526static inline void ftrace_free_init_mem(void) { }
527static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
528static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs)
529{
530 return -EOPNOTSUPP;
531}
532#endif /* CONFIG_FUNCTION_TRACER */
533
534struct ftrace_func_entry {
535 struct hlist_node hlist;
536 unsigned long ip;
537 unsigned long direct; /* for direct lookup only */
538};
539
540#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
541unsigned long ftrace_find_rec_direct(unsigned long ip);
542int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr);
543int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
544 bool free_filters);
545int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr);
546int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr);
547
548int update_ftrace_direct_add(struct ftrace_ops *ops, struct ftrace_hash *hash);
549int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash);
550int update_ftrace_direct_mod(struct ftrace_ops *ops, struct ftrace_hash *hash, bool do_direct_lock);
551
552void ftrace_stub_direct_tramp(void);
553
554#else
555struct ftrace_ops;
556static inline unsigned long ftrace_find_rec_direct(unsigned long ip)
557{
558 return 0;
559}
560static inline int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
561{
562 return -ENODEV;
563}
564static inline int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
565 bool free_filters)
566{
567 return -ENODEV;
568}
569static inline int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
570{
571 return -ENODEV;
572}
573static inline int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr)
574{
575 return -ENODEV;
576}
577
578static inline int update_ftrace_direct_add(struct ftrace_ops *ops, struct ftrace_hash *hash)
579{
580 return -ENODEV;
581}
582
583static inline int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash)
584{
585 return -ENODEV;
586}
587
588static inline int update_ftrace_direct_mod(struct ftrace_ops *ops, struct ftrace_hash *hash, bool do_direct_lock)
589{
590 return -ENODEV;
591}
592
593/*
594 * This must be implemented by the architecture.
595 * It is the way the ftrace direct_ops helper, when called
596 * via ftrace (because there's other callbacks besides the
597 * direct call), can inform the architecture's trampoline that this
598 * routine has a direct caller, and what the caller is.
599 *
600 * For example, in x86, it returns the direct caller
601 * callback function via the regs->orig_ax parameter.
602 * Then in the ftrace trampoline, if this is set, it makes
603 * the return from the trampoline jump to the direct caller
604 * instead of going back to the function it just traced.
605 */
606static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs,
607 unsigned long addr) { }
608#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
609
610#ifdef CONFIG_DYNAMIC_FTRACE_WITH_JMP
611static inline bool ftrace_is_jmp(unsigned long addr)
612{
613 return addr & 1;
614}
615
616static inline unsigned long ftrace_jmp_set(unsigned long addr)
617{
618 return addr | 1UL;
619}
620
621static inline unsigned long ftrace_jmp_get(unsigned long addr)
622{
623 return addr & ~1UL;
624}
625#else
626static inline bool ftrace_is_jmp(unsigned long addr)
627{
628 return false;
629}
630
631static inline unsigned long ftrace_jmp_set(unsigned long addr)
632{
633 return addr;
634}
635
636static inline unsigned long ftrace_jmp_get(unsigned long addr)
637{
638 return addr;
639}
640#endif /* CONFIG_DYNAMIC_FTRACE_WITH_JMP */
641
642#ifdef CONFIG_STACK_TRACER
643
644int stack_trace_sysctl(const struct ctl_table *table, int write, void *buffer,
645 size_t *lenp, loff_t *ppos);
646
647/* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
648DECLARE_PER_CPU(int, disable_stack_tracer);
649
650/**
651 * stack_tracer_disable - temporarily disable the stack tracer
652 *
653 * There's a few locations (namely in RCU) where stack tracing
654 * cannot be executed. This function is used to disable stack
655 * tracing during those critical sections.
656 *
657 * This function must be called with preemption or interrupts
658 * disabled and stack_tracer_enable() must be called shortly after
659 * while preemption or interrupts are still disabled.
660 */
661static inline void stack_tracer_disable(void)
662{
663 /* Preemption or interrupts must be disabled */
664 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
665 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
666 this_cpu_inc(disable_stack_tracer);
667}
668
669/**
670 * stack_tracer_enable - re-enable the stack tracer
671 *
672 * After stack_tracer_disable() is called, stack_tracer_enable()
673 * must be called shortly afterward.
674 */
675static inline void stack_tracer_enable(void)
676{
677 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
678 WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
679 this_cpu_dec(disable_stack_tracer);
680}
681#else
682static inline void stack_tracer_disable(void) { }
683static inline void stack_tracer_enable(void) { }
684#endif
685
686enum {
687 FTRACE_UPDATE_CALLS = (1 << 0),
688 FTRACE_DISABLE_CALLS = (1 << 1),
689 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
690 FTRACE_START_FUNC_RET = (1 << 3),
691 FTRACE_STOP_FUNC_RET = (1 << 4),
692 FTRACE_MAY_SLEEP = (1 << 5),
693};
694
695/* Arches can override ftrace_get_symaddr() to convert fentry_ip to symaddr. */
696#ifndef ftrace_get_symaddr
697/**
698 * ftrace_get_symaddr - return the symbol address from fentry_ip
699 * @fentry_ip: the address of ftrace location
700 *
701 * Get the symbol address from @fentry_ip (fast path). If there is no fast
702 * search path, this returns 0.
703 * User may need to use kallsyms API to find the symbol address.
704 */
705#define ftrace_get_symaddr(fentry_ip) (0)
706#endif
707
708void ftrace_sync_ipi(void *data);
709
710#ifdef CONFIG_DYNAMIC_FTRACE
711
712void ftrace_arch_code_modify_prepare(void);
713void ftrace_arch_code_modify_post_process(void);
714
715enum ftrace_bug_type {
716 FTRACE_BUG_UNKNOWN,
717 FTRACE_BUG_INIT,
718 FTRACE_BUG_NOP,
719 FTRACE_BUG_CALL,
720 FTRACE_BUG_UPDATE,
721};
722extern enum ftrace_bug_type ftrace_bug_type;
723
724/*
725 * Archs can set this to point to a variable that holds the value that was
726 * expected at the call site before calling ftrace_bug().
727 */
728extern const void *ftrace_expected;
729
730void ftrace_bug(int err, struct dyn_ftrace *rec);
731
732struct seq_file;
733
734extern int ftrace_text_reserved(const void *start, const void *end);
735
736struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
737
738bool is_ftrace_trampoline(unsigned long addr);
739
740/*
741 * The dyn_ftrace record's flags field is split into two parts.
742 * the first part which is '0-FTRACE_REF_MAX' is a counter of
743 * the number of callbacks that have registered the function that
744 * the dyn_ftrace descriptor represents.
745 *
746 * The second part is a mask:
747 * ENABLED - the function is being traced
748 * REGS - the record wants the function to save regs
749 * REGS_EN - the function is set up to save regs.
750 * IPMODIFY - the record allows for the IP address to be changed.
751 * DISABLED - the record is not ready to be touched yet
752 * DIRECT - there is a direct function to call
753 * CALL_OPS - the record can use callsite-specific ops
754 * CALL_OPS_EN - the function is set up to use callsite-specific ops
755 * TOUCHED - A callback was added since boot up
756 * MODIFIED - The function had IPMODIFY or DIRECT attached to it
757 *
758 * When a new ftrace_ops is registered and wants a function to save
759 * pt_regs, the rec->flags REGS is set. When the function has been
760 * set up to save regs, the REG_EN flag is set. Once a function
761 * starts saving regs it will do so until all ftrace_ops are removed
762 * from tracing that function.
763 */
764enum {
765 FTRACE_FL_ENABLED = (1UL << 31),
766 FTRACE_FL_REGS = (1UL << 30),
767 FTRACE_FL_REGS_EN = (1UL << 29),
768 FTRACE_FL_TRAMP = (1UL << 28),
769 FTRACE_FL_TRAMP_EN = (1UL << 27),
770 FTRACE_FL_IPMODIFY = (1UL << 26),
771 FTRACE_FL_DISABLED = (1UL << 25),
772 FTRACE_FL_DIRECT = (1UL << 24),
773 FTRACE_FL_DIRECT_EN = (1UL << 23),
774 FTRACE_FL_CALL_OPS = (1UL << 22),
775 FTRACE_FL_CALL_OPS_EN = (1UL << 21),
776 FTRACE_FL_TOUCHED = (1UL << 20),
777 FTRACE_FL_MODIFIED = (1UL << 19),
778};
779
780#define FTRACE_REF_MAX_SHIFT 19
781#define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
782
783#define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX)
784
785struct dyn_ftrace {
786 unsigned long ip; /* address of mcount call-site */
787 unsigned long flags;
788 struct dyn_arch_ftrace arch;
789};
790
791int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
792 int remove, int reset);
793int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,
794 unsigned int cnt, int remove, int reset);
795int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
796 int len, int reset);
797int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
798 int len, int reset);
799void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
800void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
801void ftrace_free_filter(struct ftrace_ops *ops);
802void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
803
804/*
805 * The FTRACE_UPDATE_* enum is used to pass information back
806 * from the ftrace_update_record() and ftrace_test_record()
807 * functions. These are called by the code update routines
808 * to find out what is to be done for a given function.
809 *
810 * IGNORE - The function is already what we want it to be
811 * MAKE_CALL - Start tracing the function
812 * MODIFY_CALL - Stop saving regs for the function
813 * MAKE_NOP - Stop tracing the function
814 */
815enum {
816 FTRACE_UPDATE_IGNORE,
817 FTRACE_UPDATE_MAKE_CALL,
818 FTRACE_UPDATE_MODIFY_CALL,
819 FTRACE_UPDATE_MAKE_NOP,
820};
821
822enum {
823 FTRACE_ITER_FILTER = (1 << 0),
824 FTRACE_ITER_NOTRACE = (1 << 1),
825 FTRACE_ITER_PRINTALL = (1 << 2),
826 FTRACE_ITER_DO_PROBES = (1 << 3),
827 FTRACE_ITER_PROBE = (1 << 4),
828 FTRACE_ITER_MOD = (1 << 5),
829 FTRACE_ITER_ENABLED = (1 << 6),
830 FTRACE_ITER_TOUCHED = (1 << 7),
831 FTRACE_ITER_ADDRS = (1 << 8),
832};
833
834void arch_ftrace_update_code(int command);
835void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
836void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
837void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
838
839struct ftrace_rec_iter;
840
841struct ftrace_rec_iter *ftrace_rec_iter_start(void);
842struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
843struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
844
845#define for_ftrace_rec_iter(iter) \
846 for (iter = ftrace_rec_iter_start(); \
847 iter; \
848 iter = ftrace_rec_iter_next(iter))
849
850
851int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
852int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
853void ftrace_run_stop_machine(int command);
854unsigned long ftrace_location(unsigned long ip);
855unsigned long ftrace_location_range(unsigned long start, unsigned long end);
856unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
857unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
858
859extern ftrace_func_t ftrace_trace_function;
860
861int ftrace_regex_open(struct ftrace_ops *ops, int flag,
862 struct inode *inode, struct file *file);
863ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
864 size_t cnt, loff_t *ppos);
865ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
866 size_t cnt, loff_t *ppos);
867int ftrace_regex_release(struct inode *inode, struct file *file);
868
869void __init
870ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
871
872/* defined in arch */
873extern int ftrace_dyn_arch_init(void);
874extern void ftrace_replace_code(int enable);
875extern int ftrace_update_ftrace_func(ftrace_func_t func);
876extern void ftrace_caller(void);
877extern void ftrace_regs_caller(void);
878extern void ftrace_call(void);
879extern void ftrace_regs_call(void);
880extern void mcount_call(void);
881
882void ftrace_modify_all_code(int command);
883
884#ifndef FTRACE_ADDR
885#define FTRACE_ADDR ((unsigned long)ftrace_caller)
886#endif
887
888#ifndef FTRACE_GRAPH_ADDR
889#define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
890#endif
891
892#ifndef FTRACE_REGS_ADDR
893#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
894# define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
895#else
896# define FTRACE_REGS_ADDR FTRACE_ADDR
897#endif
898#endif
899
900/*
901 * If an arch would like functions that are only traced
902 * by the function graph tracer to jump directly to its own
903 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
904 * to be that address to jump to.
905 */
906#ifndef FTRACE_GRAPH_TRAMP_ADDR
907#define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
908#endif
909
910#ifdef CONFIG_FUNCTION_GRAPH_TRACER
911extern void ftrace_graph_caller(void);
912extern int ftrace_enable_ftrace_graph_caller(void);
913extern int ftrace_disable_ftrace_graph_caller(void);
914#else
915static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
916static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
917#endif
918
919/**
920 * ftrace_make_nop - convert code into nop
921 * @mod: module structure if called by module load initialization
922 * @rec: the call site record (e.g. mcount/fentry)
923 * @addr: the address that the call site should be calling
924 *
925 * This is a very sensitive operation and great care needs
926 * to be taken by the arch. The operation should carefully
927 * read the location, check to see if what is read is indeed
928 * what we expect it to be, and then on success of the compare,
929 * it should write to the location.
930 *
931 * The code segment at @rec->ip should be a caller to @addr
932 *
933 * Return must be:
934 * 0 on success
935 * -EFAULT on error reading the location
936 * -EINVAL on a failed compare of the contents
937 * -EPERM on error writing to the location
938 * Any other value will be considered a failure.
939 */
940extern int ftrace_make_nop(struct module *mod,
941 struct dyn_ftrace *rec, unsigned long addr);
942
943/**
944 * ftrace_need_init_nop - return whether nop call sites should be initialized
945 *
946 * Normally the compiler's -mnop-mcount generates suitable nops, so we don't
947 * need to call ftrace_init_nop() if the code is built with that flag.
948 * Architectures where this is not always the case may define their own
949 * condition.
950 *
951 * Return must be:
952 * 0 if ftrace_init_nop() should be called
953 * Nonzero if ftrace_init_nop() should not be called
954 */
955
956#ifndef ftrace_need_init_nop
957#define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT))
958#endif
959
960/**
961 * ftrace_init_nop - initialize a nop call site
962 * @mod: module structure if called by module load initialization
963 * @rec: the call site record (e.g. mcount/fentry)
964 *
965 * This is a very sensitive operation and great care needs
966 * to be taken by the arch. The operation should carefully
967 * read the location, check to see if what is read is indeed
968 * what we expect it to be, and then on success of the compare,
969 * it should write to the location.
970 *
971 * The code segment at @rec->ip should contain the contents created by
972 * the compiler
973 *
974 * Return must be:
975 * 0 on success
976 * -EFAULT on error reading the location
977 * -EINVAL on a failed compare of the contents
978 * -EPERM on error writing to the location
979 * Any other value will be considered a failure.
980 */
981#ifndef ftrace_init_nop
982static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
983{
984 return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
985}
986#endif
987
988/**
989 * ftrace_make_call - convert a nop call site into a call to addr
990 * @rec: the call site record (e.g. mcount/fentry)
991 * @addr: the address that the call site should call
992 *
993 * This is a very sensitive operation and great care needs
994 * to be taken by the arch. The operation should carefully
995 * read the location, check to see if what is read is indeed
996 * what we expect it to be, and then on success of the compare,
997 * it should write to the location.
998 *
999 * The code segment at @rec->ip should be a nop
1000 *
1001 * Return must be:
1002 * 0 on success
1003 * -EFAULT on error reading the location
1004 * -EINVAL on a failed compare of the contents
1005 * -EPERM on error writing to the location
1006 * Any other value will be considered a failure.
1007 */
1008extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
1009
1010#if defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) || \
1011 defined(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) || \
1012 defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS)
1013/**
1014 * ftrace_modify_call - convert from one addr to another (no nop)
1015 * @rec: the call site record (e.g. mcount/fentry)
1016 * @old_addr: the address expected to be currently called to
1017 * @addr: the address to change to
1018 *
1019 * This is a very sensitive operation and great care needs
1020 * to be taken by the arch. The operation should carefully
1021 * read the location, check to see if what is read is indeed
1022 * what we expect it to be, and then on success of the compare,
1023 * it should write to the location.
1024 *
1025 * When using call ops, this is called when the associated ops change, even
1026 * when (addr == old_addr).
1027 *
1028 * The code segment at @rec->ip should be a caller to @old_addr
1029 *
1030 * Return must be:
1031 * 0 on success
1032 * -EFAULT on error reading the location
1033 * -EINVAL on a failed compare of the contents
1034 * -EPERM on error writing to the location
1035 * Any other value will be considered a failure.
1036 */
1037extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
1038 unsigned long addr);
1039#else
1040/* Should never be called */
1041static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
1042 unsigned long addr)
1043{
1044 return -EINVAL;
1045}
1046#endif
1047
1048extern int skip_trace(unsigned long ip);
1049extern void ftrace_module_init(struct module *mod);
1050extern void ftrace_module_enable(struct module *mod);
1051extern void ftrace_release_mod(struct module *mod);
1052#else /* CONFIG_DYNAMIC_FTRACE */
1053static inline int skip_trace(unsigned long ip) { return 0; }
1054static inline void ftrace_module_init(struct module *mod) { }
1055static inline void ftrace_module_enable(struct module *mod) { }
1056static inline void ftrace_release_mod(struct module *mod) { }
1057static inline int ftrace_text_reserved(const void *start, const void *end)
1058{
1059 return 0;
1060}
1061static inline unsigned long ftrace_location(unsigned long ip)
1062{
1063 return 0;
1064}
1065
1066/*
1067 * Again users of functions that have ftrace_ops may not
1068 * have them defined when ftrace is not enabled, but these
1069 * functions may still be called. Use a macro instead of inline.
1070 */
1071#define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
1072#define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
1073#define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
1074#define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; })
1075#define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
1076#define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
1077#define ftrace_free_filter(ops) do { } while (0)
1078#define ftrace_ops_set_global_filter(ops) do { } while (0)
1079
1080static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
1081 size_t cnt, loff_t *ppos) { return -ENODEV; }
1082static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
1083 size_t cnt, loff_t *ppos) { return -ENODEV; }
1084static inline int
1085ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
1086
1087static inline bool is_ftrace_trampoline(unsigned long addr)
1088{
1089 return false;
1090}
1091#endif /* CONFIG_DYNAMIC_FTRACE */
1092
1093#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1094#ifndef ftrace_graph_func
1095# define ftrace_graph_func ftrace_stub
1096# define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB
1097/*
1098 * The function graph is called every time the function tracer is called.
1099 * It must always test the ops hash and cannot just directly call
1100 * the handler.
1101 */
1102# define FGRAPH_NO_DIRECT 1
1103#else
1104# define FTRACE_OPS_GRAPH_STUB 0
1105# define FGRAPH_NO_DIRECT 0
1106#endif
1107#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1108
1109/* totally disable ftrace - can not re-enable after this */
1110void ftrace_kill(void);
1111
1112static inline void tracer_disable(void)
1113{
1114#ifdef CONFIG_FUNCTION_TRACER
1115 ftrace_enabled = 0;
1116#endif
1117}
1118
1119/*
1120 * Ftrace disable/restore without lock. Some synchronization mechanism
1121 * must be used to prevent ftrace_enabled to be changed between
1122 * disable/restore.
1123 */
1124static inline int __ftrace_enabled_save(void)
1125{
1126#ifdef CONFIG_FUNCTION_TRACER
1127 int saved_ftrace_enabled = ftrace_enabled;
1128 ftrace_enabled = 0;
1129 return saved_ftrace_enabled;
1130#else
1131 return 0;
1132#endif
1133}
1134
1135static inline void __ftrace_enabled_restore(int enabled)
1136{
1137#ifdef CONFIG_FUNCTION_TRACER
1138 ftrace_enabled = enabled;
1139#endif
1140}
1141
1142/* All archs should have this, but we define it for consistency */
1143#ifndef ftrace_return_address0
1144# define ftrace_return_address0 __builtin_return_address(0)
1145#endif
1146
1147/* Archs may use other ways for ADDR1 and beyond */
1148#ifndef ftrace_return_address
1149# ifdef CONFIG_FRAME_POINTER
1150# define ftrace_return_address(n) __builtin_return_address(n)
1151# else
1152# define ftrace_return_address(n) 0UL
1153# endif
1154#endif
1155
1156#define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
1157#define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
1158#define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
1159#define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
1160#define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
1161#define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
1162#define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
1163
1164static __always_inline unsigned long get_lock_parent_ip(void)
1165{
1166 unsigned long addr = CALLER_ADDR0;
1167
1168 if (!in_lock_functions(addr))
1169 return addr;
1170 addr = CALLER_ADDR1;
1171 if (!in_lock_functions(addr))
1172 return addr;
1173 return CALLER_ADDR2;
1174}
1175
1176#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
1177 extern void trace_preempt_on(unsigned long a0, unsigned long a1);
1178 extern void trace_preempt_off(unsigned long a0, unsigned long a1);
1179#else
1180/*
1181 * Use defines instead of static inlines because some arches will make code out
1182 * of the CALLER_ADDR, when we really want these to be a real nop.
1183 */
1184# define trace_preempt_on(a0, a1) do { } while (0)
1185# define trace_preempt_off(a0, a1) do { } while (0)
1186#endif
1187
1188#ifdef CONFIG_DYNAMIC_FTRACE
1189extern void ftrace_init(void);
1190#ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
1191#define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
1192#else
1193#define FTRACE_CALLSITE_SECTION "__mcount_loc"
1194#endif
1195#else
1196static inline void ftrace_init(void) { }
1197#endif
1198
1199/*
1200 * Structure that defines an entry function trace.
1201 * It's already packed but the attribute "packed" is needed
1202 * to remove extra padding at the end.
1203 */
1204struct ftrace_graph_ent {
1205 unsigned long func; /* Current function */
1206 long depth; /* signed to check for less than zero */
1207} __packed;
1208
1209/*
1210 * Structure that defines an entry function trace with retaddr.
1211 */
1212struct fgraph_retaddr_ent {
1213 struct ftrace_graph_ent ent;
1214 unsigned long retaddr; /* Return address */
1215} __packed;
1216
1217/*
1218 * Structure that defines a return function trace.
1219 * It's already packed but the attribute "packed" is needed
1220 * to remove extra padding at the end.
1221 */
1222struct ftrace_graph_ret {
1223 unsigned long func; /* Current function */
1224#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
1225 unsigned long retval;
1226#endif
1227 int depth;
1228 /* Number of functions that overran the depth limit for current task */
1229 unsigned int overrun;
1230} __packed;
1231
1232struct fgraph_ops;
1233
1234/* Type of the callback handlers for tracing function graph*/
1235typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *,
1236 struct fgraph_ops *,
1237 struct ftrace_regs *); /* return */
1238typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *,
1239 struct fgraph_ops *,
1240 struct ftrace_regs *); /* entry */
1241
1242extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace,
1243 struct fgraph_ops *gops,
1244 struct ftrace_regs *fregs);
1245bool ftrace_pids_enabled(struct ftrace_ops *ops);
1246
1247#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1248
1249struct fgraph_ops {
1250 trace_func_graph_ent_t entryfunc;
1251 trace_func_graph_ret_t retfunc;
1252 struct ftrace_ops ops; /* for the hash lists */
1253 void *private;
1254 trace_func_graph_ent_t saved_func;
1255 int idx;
1256};
1257
1258void *fgraph_reserve_data(int idx, int size_bytes);
1259void *fgraph_retrieve_data(int idx, int *size_bytes);
1260void *fgraph_retrieve_parent_data(int idx, int *size_bytes, int depth);
1261
1262/*
1263 * Stack of return addresses for functions
1264 * of a thread.
1265 * Used in struct thread_info
1266 */
1267struct ftrace_ret_stack {
1268 unsigned long ret;
1269 unsigned long func;
1270#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
1271 unsigned long fp;
1272#endif
1273 unsigned long *retp;
1274};
1275
1276/*
1277 * Primary handler of a function return.
1278 * It relays on ftrace_return_to_handler.
1279 * Defined in entry_32/64.S
1280 */
1281extern void return_to_handler(void);
1282
1283extern int
1284function_graph_enter_regs(unsigned long ret, unsigned long func,
1285 unsigned long frame_pointer, unsigned long *retp,
1286 struct ftrace_regs *fregs);
1287
1288static inline int function_graph_enter(unsigned long ret, unsigned long func,
1289 unsigned long fp, unsigned long *retp)
1290{
1291 return function_graph_enter_regs(ret, func, fp, retp, NULL);
1292}
1293
1294struct ftrace_ret_stack *
1295ftrace_graph_get_ret_stack(struct task_struct *task, int skip);
1296unsigned long ftrace_graph_top_ret_addr(struct task_struct *task);
1297
1298unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
1299 unsigned long ret, unsigned long *retp);
1300unsigned long *fgraph_get_task_var(struct fgraph_ops *gops);
1301
1302/*
1303 * Sometimes we don't want to trace a function with the function
1304 * graph tracer but we want them to keep traced by the usual function
1305 * tracer if the function graph tracer is not configured.
1306 */
1307#define __notrace_funcgraph notrace
1308
1309#define FTRACE_RETFUNC_DEPTH 50
1310#define FTRACE_RETSTACK_ALLOC_SIZE 32
1311
1312extern int register_ftrace_graph(struct fgraph_ops *ops);
1313extern void unregister_ftrace_graph(struct fgraph_ops *ops);
1314
1315/**
1316 * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called
1317 *
1318 * ftrace_graph_stop() is called when a severe error is detected in
1319 * the function graph tracing. This function is called by the critical
1320 * paths of function graph to keep those paths from doing any more harm.
1321 */
1322DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph);
1323
1324static inline bool ftrace_graph_is_dead(void)
1325{
1326 return static_branch_unlikely(&kill_ftrace_graph);
1327}
1328
1329extern void ftrace_graph_stop(void);
1330
1331/* The current handlers in use */
1332extern trace_func_graph_ret_t ftrace_graph_return;
1333extern trace_func_graph_ent_t ftrace_graph_entry;
1334
1335extern void ftrace_graph_init_task(struct task_struct *t);
1336extern void ftrace_graph_exit_task(struct task_struct *t);
1337extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
1338
1339/* Used by assembly, but to quiet sparse warnings */
1340extern struct ftrace_ops *function_trace_op;
1341
1342static inline void pause_graph_tracing(void)
1343{
1344 atomic_inc(¤t->tracing_graph_pause);
1345}
1346
1347static inline void unpause_graph_tracing(void)
1348{
1349 atomic_dec(¤t->tracing_graph_pause);
1350}
1351#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
1352
1353#define __notrace_funcgraph
1354
1355static inline void ftrace_graph_init_task(struct task_struct *t) { }
1356static inline void ftrace_graph_exit_task(struct task_struct *t) { }
1357static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
1358
1359/* Define as macros as fgraph_ops may not be defined */
1360#define register_ftrace_graph(ops) ({ -1; })
1361#define unregister_ftrace_graph(ops) do { } while (0)
1362
1363static inline unsigned long
1364ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
1365 unsigned long *retp)
1366{
1367 return ret;
1368}
1369
1370static inline void pause_graph_tracing(void) { }
1371static inline void unpause_graph_tracing(void) { }
1372#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1373
1374#ifdef CONFIG_TRACING
1375enum ftrace_dump_mode;
1376
1377extern int ftrace_dump_on_oops_enabled(void);
1378
1379extern void disable_trace_on_warning(void);
1380
1381#else /* CONFIG_TRACING */
1382static inline void disable_trace_on_warning(void) { }
1383#endif /* CONFIG_TRACING */
1384
1385#ifdef CONFIG_FTRACE_SYSCALLS
1386
1387unsigned long arch_syscall_addr(int nr);
1388
1389#endif /* CONFIG_FTRACE_SYSCALLS */
1390
1391#endif /* _LINUX_FTRACE_H */