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