xref: /linux-6.15/include/linux/ftrace.h (revision 6fcd5f2c)
1 /*
2  * Ftrace header.  For implementation details beyond the random comments
3  * scattered below, see: Documentation/trace/ftrace-design.txt
4  */
5 
6 #ifndef _LINUX_FTRACE_H
7 #define _LINUX_FTRACE_H
8 
9 #include <linux/trace_clock.h>
10 #include <linux/kallsyms.h>
11 #include <linux/linkage.h>
12 #include <linux/bitops.h>
13 #include <linux/ktime.h>
14 #include <linux/sched.h>
15 #include <linux/types.h>
16 #include <linux/init.h>
17 #include <linux/fs.h>
18 
19 #include <asm/ftrace.h>
20 
21 struct module;
22 struct ftrace_hash;
23 
24 #ifdef CONFIG_FUNCTION_TRACER
25 
26 extern int ftrace_enabled;
27 extern int
28 ftrace_enable_sysctl(struct ctl_table *table, int write,
29 		     void __user *buffer, size_t *lenp,
30 		     loff_t *ppos);
31 
32 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
33 
34 /*
35  * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
36  * set in the flags member.
37  *
38  * ENABLED - set/unset when ftrace_ops is registered/unregistered
39  * GLOBAL  - set manualy by ftrace_ops user to denote the ftrace_ops
40  *           is part of the global tracers sharing the same filter
41  *           via set_ftrace_* debugfs files.
42  * DYNAMIC - set when ftrace_ops is registered to denote dynamically
43  *           allocated ftrace_ops which need special care
44  * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
45  *           could be controled by following calls:
46  *             ftrace_function_local_enable
47  *             ftrace_function_local_disable
48  */
49 enum {
50 	FTRACE_OPS_FL_ENABLED		= 1 << 0,
51 	FTRACE_OPS_FL_GLOBAL		= 1 << 1,
52 	FTRACE_OPS_FL_DYNAMIC		= 1 << 2,
53 	FTRACE_OPS_FL_CONTROL		= 1 << 3,
54 };
55 
56 struct ftrace_ops {
57 	ftrace_func_t			func;
58 	struct ftrace_ops		*next;
59 	unsigned long			flags;
60 	int __percpu			*disabled;
61 #ifdef CONFIG_DYNAMIC_FTRACE
62 	struct ftrace_hash		*notrace_hash;
63 	struct ftrace_hash		*filter_hash;
64 #endif
65 };
66 
67 extern int function_trace_stop;
68 
69 /*
70  * Type of the current tracing.
71  */
72 enum ftrace_tracing_type_t {
73 	FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
74 	FTRACE_TYPE_RETURN,	/* Hook the return of the function */
75 };
76 
77 /* Current tracing type, default is FTRACE_TYPE_ENTER */
78 extern enum ftrace_tracing_type_t ftrace_tracing_type;
79 
80 /**
81  * ftrace_stop - stop function tracer.
82  *
83  * A quick way to stop the function tracer. Note this an on off switch,
84  * it is not something that is recursive like preempt_disable.
85  * This does not disable the calling of mcount, it only stops the
86  * calling of functions from mcount.
87  */
88 static inline void ftrace_stop(void)
89 {
90 	function_trace_stop = 1;
91 }
92 
93 /**
94  * ftrace_start - start the function tracer.
95  *
96  * This function is the inverse of ftrace_stop. This does not enable
97  * the function tracing if the function tracer is disabled. This only
98  * sets the function tracer flag to continue calling the functions
99  * from mcount.
100  */
101 static inline void ftrace_start(void)
102 {
103 	function_trace_stop = 0;
104 }
105 
106 /*
107  * The ftrace_ops must be a static and should also
108  * be read_mostly.  These functions do modify read_mostly variables
109  * so use them sparely. Never free an ftrace_op or modify the
110  * next pointer after it has been registered. Even after unregistering
111  * it, the next pointer may still be used internally.
112  */
113 int register_ftrace_function(struct ftrace_ops *ops);
114 int unregister_ftrace_function(struct ftrace_ops *ops);
115 void clear_ftrace_function(void);
116 
117 /**
118  * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
119  *
120  * This function enables tracing on current cpu by decreasing
121  * the per cpu control variable.
122  * It must be called with preemption disabled and only on ftrace_ops
123  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
124  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
125  */
126 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
127 {
128 	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
129 		return;
130 
131 	(*this_cpu_ptr(ops->disabled))--;
132 }
133 
134 /**
135  * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
136  *
137  * This function enables tracing on current cpu by decreasing
138  * the per cpu control variable.
139  * It must be called with preemption disabled and only on ftrace_ops
140  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
141  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
142  */
143 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
144 {
145 	if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
146 		return;
147 
148 	(*this_cpu_ptr(ops->disabled))++;
149 }
150 
151 /**
152  * ftrace_function_local_disabled - returns ftrace_ops disabled value
153  *                                  on current cpu
154  *
155  * This function returns value of ftrace_ops::disabled on current cpu.
156  * It must be called with preemption disabled and only on ftrace_ops
157  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
158  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
159  */
160 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
161 {
162 	WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
163 	return *this_cpu_ptr(ops->disabled);
164 }
165 
166 extern void ftrace_stub(unsigned long a0, unsigned long a1);
167 
168 #else /* !CONFIG_FUNCTION_TRACER */
169 /*
170  * (un)register_ftrace_function must be a macro since the ops parameter
171  * must not be evaluated.
172  */
173 #define register_ftrace_function(ops) ({ 0; })
174 #define unregister_ftrace_function(ops) ({ 0; })
175 static inline void clear_ftrace_function(void) { }
176 static inline void ftrace_kill(void) { }
177 static inline void ftrace_stop(void) { }
178 static inline void ftrace_start(void) { }
179 #endif /* CONFIG_FUNCTION_TRACER */
180 
181 #ifdef CONFIG_STACK_TRACER
182 extern int stack_tracer_enabled;
183 int
184 stack_trace_sysctl(struct ctl_table *table, int write,
185 		   void __user *buffer, size_t *lenp,
186 		   loff_t *ppos);
187 #endif
188 
189 struct ftrace_func_command {
190 	struct list_head	list;
191 	char			*name;
192 	int			(*func)(struct ftrace_hash *hash,
193 					char *func, char *cmd,
194 					char *params, int enable);
195 };
196 
197 #ifdef CONFIG_DYNAMIC_FTRACE
198 
199 int ftrace_arch_code_modify_prepare(void);
200 int ftrace_arch_code_modify_post_process(void);
201 
202 void ftrace_bug(int err, unsigned long ip);
203 
204 struct seq_file;
205 
206 struct ftrace_probe_ops {
207 	void			(*func)(unsigned long ip,
208 					unsigned long parent_ip,
209 					void **data);
210 	int			(*callback)(unsigned long ip, void **data);
211 	void			(*free)(void **data);
212 	int			(*print)(struct seq_file *m,
213 					 unsigned long ip,
214 					 struct ftrace_probe_ops *ops,
215 					 void *data);
216 };
217 
218 extern int
219 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
220 			      void *data);
221 extern void
222 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
223 				void *data);
224 extern void
225 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
226 extern void unregister_ftrace_function_probe_all(char *glob);
227 
228 extern int ftrace_text_reserved(void *start, void *end);
229 
230 enum {
231 	FTRACE_FL_ENABLED	= (1 << 30),
232 };
233 
234 #define FTRACE_FL_MASK		(0x3UL << 30)
235 #define FTRACE_REF_MAX		((1 << 30) - 1)
236 
237 struct dyn_ftrace {
238 	union {
239 		unsigned long		ip; /* address of mcount call-site */
240 		struct dyn_ftrace	*freelist;
241 	};
242 	unsigned long		flags;
243 	struct dyn_arch_ftrace		arch;
244 };
245 
246 int ftrace_force_update(void);
247 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
248 		       int len, int reset);
249 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
250 			int len, int reset);
251 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
252 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
253 void ftrace_free_filter(struct ftrace_ops *ops);
254 
255 int register_ftrace_command(struct ftrace_func_command *cmd);
256 int unregister_ftrace_command(struct ftrace_func_command *cmd);
257 
258 enum {
259 	FTRACE_UPDATE_CALLS		= (1 << 0),
260 	FTRACE_DISABLE_CALLS		= (1 << 1),
261 	FTRACE_UPDATE_TRACE_FUNC	= (1 << 2),
262 	FTRACE_START_FUNC_RET		= (1 << 3),
263 	FTRACE_STOP_FUNC_RET		= (1 << 4),
264 };
265 
266 enum {
267 	FTRACE_UPDATE_IGNORE,
268 	FTRACE_UPDATE_MAKE_CALL,
269 	FTRACE_UPDATE_MAKE_NOP,
270 };
271 
272 enum {
273 	FTRACE_ITER_FILTER	= (1 << 0),
274 	FTRACE_ITER_NOTRACE	= (1 << 1),
275 	FTRACE_ITER_PRINTALL	= (1 << 2),
276 	FTRACE_ITER_DO_HASH	= (1 << 3),
277 	FTRACE_ITER_HASH	= (1 << 4),
278 	FTRACE_ITER_ENABLED	= (1 << 5),
279 };
280 
281 void arch_ftrace_update_code(int command);
282 
283 struct ftrace_rec_iter;
284 
285 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
286 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
287 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
288 
289 #define for_ftrace_rec_iter(iter)		\
290 	for (iter = ftrace_rec_iter_start();	\
291 	     iter;				\
292 	     iter = ftrace_rec_iter_next(iter))
293 
294 
295 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
296 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
297 void ftrace_run_stop_machine(int command);
298 unsigned long ftrace_location(unsigned long ip);
299 
300 extern ftrace_func_t ftrace_trace_function;
301 
302 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
303 		  struct inode *inode, struct file *file);
304 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
305 			    size_t cnt, loff_t *ppos);
306 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
307 			     size_t cnt, loff_t *ppos);
308 loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin);
309 int ftrace_regex_release(struct inode *inode, struct file *file);
310 
311 void __init
312 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
313 
314 /* defined in arch */
315 extern int ftrace_ip_converted(unsigned long ip);
316 extern int ftrace_dyn_arch_init(void *data);
317 extern void ftrace_replace_code(int enable);
318 extern int ftrace_update_ftrace_func(ftrace_func_t func);
319 extern void ftrace_caller(void);
320 extern void ftrace_call(void);
321 extern void mcount_call(void);
322 
323 void ftrace_modify_all_code(int command);
324 
325 #ifndef FTRACE_ADDR
326 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
327 #endif
328 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
329 extern void ftrace_graph_caller(void);
330 extern int ftrace_enable_ftrace_graph_caller(void);
331 extern int ftrace_disable_ftrace_graph_caller(void);
332 #else
333 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
334 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
335 #endif
336 
337 /**
338  * ftrace_make_nop - convert code into nop
339  * @mod: module structure if called by module load initialization
340  * @rec: the mcount call site record
341  * @addr: the address that the call site should be calling
342  *
343  * This is a very sensitive operation and great care needs
344  * to be taken by the arch.  The operation should carefully
345  * read the location, check to see if what is read is indeed
346  * what we expect it to be, and then on success of the compare,
347  * it should write to the location.
348  *
349  * The code segment at @rec->ip should be a caller to @addr
350  *
351  * Return must be:
352  *  0 on success
353  *  -EFAULT on error reading the location
354  *  -EINVAL on a failed compare of the contents
355  *  -EPERM  on error writing to the location
356  * Any other value will be considered a failure.
357  */
358 extern int ftrace_make_nop(struct module *mod,
359 			   struct dyn_ftrace *rec, unsigned long addr);
360 
361 /**
362  * ftrace_make_call - convert a nop call site into a call to addr
363  * @rec: the mcount call site record
364  * @addr: the address that the call site should call
365  *
366  * This is a very sensitive operation and great care needs
367  * to be taken by the arch.  The operation should carefully
368  * read the location, check to see if what is read is indeed
369  * what we expect it to be, and then on success of the compare,
370  * it should write to the location.
371  *
372  * The code segment at @rec->ip should be a nop
373  *
374  * Return must be:
375  *  0 on success
376  *  -EFAULT on error reading the location
377  *  -EINVAL on a failed compare of the contents
378  *  -EPERM  on error writing to the location
379  * Any other value will be considered a failure.
380  */
381 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
382 
383 /* May be defined in arch */
384 extern int ftrace_arch_read_dyn_info(char *buf, int size);
385 
386 extern int skip_trace(unsigned long ip);
387 
388 extern void ftrace_disable_daemon(void);
389 extern void ftrace_enable_daemon(void);
390 #else
391 static inline int skip_trace(unsigned long ip) { return 0; }
392 static inline int ftrace_force_update(void) { return 0; }
393 static inline void ftrace_disable_daemon(void) { }
394 static inline void ftrace_enable_daemon(void) { }
395 static inline void ftrace_release_mod(struct module *mod) {}
396 static inline int register_ftrace_command(struct ftrace_func_command *cmd)
397 {
398 	return -EINVAL;
399 }
400 static inline int unregister_ftrace_command(char *cmd_name)
401 {
402 	return -EINVAL;
403 }
404 static inline int ftrace_text_reserved(void *start, void *end)
405 {
406 	return 0;
407 }
408 
409 /*
410  * Again users of functions that have ftrace_ops may not
411  * have them defined when ftrace is not enabled, but these
412  * functions may still be called. Use a macro instead of inline.
413  */
414 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
415 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
416 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
417 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
418 #define ftrace_free_filter(ops) do { } while (0)
419 
420 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
421 			    size_t cnt, loff_t *ppos) { return -ENODEV; }
422 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
423 			     size_t cnt, loff_t *ppos) { return -ENODEV; }
424 static inline loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
425 {
426 	return -ENODEV;
427 }
428 static inline int
429 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
430 #endif /* CONFIG_DYNAMIC_FTRACE */
431 
432 /* totally disable ftrace - can not re-enable after this */
433 void ftrace_kill(void);
434 
435 static inline void tracer_disable(void)
436 {
437 #ifdef CONFIG_FUNCTION_TRACER
438 	ftrace_enabled = 0;
439 #endif
440 }
441 
442 /*
443  * Ftrace disable/restore without lock. Some synchronization mechanism
444  * must be used to prevent ftrace_enabled to be changed between
445  * disable/restore.
446  */
447 static inline int __ftrace_enabled_save(void)
448 {
449 #ifdef CONFIG_FUNCTION_TRACER
450 	int saved_ftrace_enabled = ftrace_enabled;
451 	ftrace_enabled = 0;
452 	return saved_ftrace_enabled;
453 #else
454 	return 0;
455 #endif
456 }
457 
458 static inline void __ftrace_enabled_restore(int enabled)
459 {
460 #ifdef CONFIG_FUNCTION_TRACER
461 	ftrace_enabled = enabled;
462 #endif
463 }
464 
465 #ifndef HAVE_ARCH_CALLER_ADDR
466 # ifdef CONFIG_FRAME_POINTER
467 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
468 #  define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
469 #  define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
470 #  define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
471 #  define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
472 #  define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
473 #  define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
474 # else
475 #  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
476 #  define CALLER_ADDR1 0UL
477 #  define CALLER_ADDR2 0UL
478 #  define CALLER_ADDR3 0UL
479 #  define CALLER_ADDR4 0UL
480 #  define CALLER_ADDR5 0UL
481 #  define CALLER_ADDR6 0UL
482 # endif
483 #endif /* ifndef HAVE_ARCH_CALLER_ADDR */
484 
485 #ifdef CONFIG_IRQSOFF_TRACER
486   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
487   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
488 #else
489   static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
490   static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
491 #endif
492 
493 #ifdef CONFIG_PREEMPT_TRACER
494   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
495   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
496 #else
497 /*
498  * Use defines instead of static inlines because some arches will make code out
499  * of the CALLER_ADDR, when we really want these to be a real nop.
500  */
501 # define trace_preempt_on(a0, a1) do { } while (0)
502 # define trace_preempt_off(a0, a1) do { } while (0)
503 #endif
504 
505 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
506 extern void ftrace_init(void);
507 #else
508 static inline void ftrace_init(void) { }
509 #endif
510 
511 /*
512  * Structure that defines an entry function trace.
513  */
514 struct ftrace_graph_ent {
515 	unsigned long func; /* Current function */
516 	int depth;
517 };
518 
519 /*
520  * Structure that defines a return function trace.
521  */
522 struct ftrace_graph_ret {
523 	unsigned long func; /* Current function */
524 	unsigned long long calltime;
525 	unsigned long long rettime;
526 	/* Number of functions that overran the depth limit for current task */
527 	unsigned long overrun;
528 	int depth;
529 };
530 
531 /* Type of the callback handlers for tracing function graph*/
532 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
533 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
534 
535 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
536 
537 /* for init task */
538 #define INIT_FTRACE_GRAPH		.ret_stack = NULL,
539 
540 /*
541  * Stack of return addresses for functions
542  * of a thread.
543  * Used in struct thread_info
544  */
545 struct ftrace_ret_stack {
546 	unsigned long ret;
547 	unsigned long func;
548 	unsigned long long calltime;
549 	unsigned long long subtime;
550 	unsigned long fp;
551 };
552 
553 /*
554  * Primary handler of a function return.
555  * It relays on ftrace_return_to_handler.
556  * Defined in entry_32/64.S
557  */
558 extern void return_to_handler(void);
559 
560 extern int
561 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
562 			 unsigned long frame_pointer);
563 
564 /*
565  * Sometimes we don't want to trace a function with the function
566  * graph tracer but we want them to keep traced by the usual function
567  * tracer if the function graph tracer is not configured.
568  */
569 #define __notrace_funcgraph		notrace
570 
571 /*
572  * We want to which function is an entrypoint of a hardirq.
573  * That will help us to put a signal on output.
574  */
575 #define __irq_entry		 __attribute__((__section__(".irqentry.text")))
576 
577 /* Limits of hardirq entrypoints */
578 extern char __irqentry_text_start[];
579 extern char __irqentry_text_end[];
580 
581 #define FTRACE_RETFUNC_DEPTH 50
582 #define FTRACE_RETSTACK_ALLOC_SIZE 32
583 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
584 				trace_func_graph_ent_t entryfunc);
585 
586 extern void ftrace_graph_stop(void);
587 
588 /* The current handlers in use */
589 extern trace_func_graph_ret_t ftrace_graph_return;
590 extern trace_func_graph_ent_t ftrace_graph_entry;
591 
592 extern void unregister_ftrace_graph(void);
593 
594 extern void ftrace_graph_init_task(struct task_struct *t);
595 extern void ftrace_graph_exit_task(struct task_struct *t);
596 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
597 
598 static inline int task_curr_ret_stack(struct task_struct *t)
599 {
600 	return t->curr_ret_stack;
601 }
602 
603 static inline void pause_graph_tracing(void)
604 {
605 	atomic_inc(&current->tracing_graph_pause);
606 }
607 
608 static inline void unpause_graph_tracing(void)
609 {
610 	atomic_dec(&current->tracing_graph_pause);
611 }
612 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
613 
614 #define __notrace_funcgraph
615 #define __irq_entry
616 #define INIT_FTRACE_GRAPH
617 
618 static inline void ftrace_graph_init_task(struct task_struct *t) { }
619 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
620 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
621 
622 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
623 			  trace_func_graph_ent_t entryfunc)
624 {
625 	return -1;
626 }
627 static inline void unregister_ftrace_graph(void) { }
628 
629 static inline int task_curr_ret_stack(struct task_struct *tsk)
630 {
631 	return -1;
632 }
633 
634 static inline void pause_graph_tracing(void) { }
635 static inline void unpause_graph_tracing(void) { }
636 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
637 
638 #ifdef CONFIG_TRACING
639 
640 /* flags for current->trace */
641 enum {
642 	TSK_TRACE_FL_TRACE_BIT	= 0,
643 	TSK_TRACE_FL_GRAPH_BIT	= 1,
644 };
645 enum {
646 	TSK_TRACE_FL_TRACE	= 1 << TSK_TRACE_FL_TRACE_BIT,
647 	TSK_TRACE_FL_GRAPH	= 1 << TSK_TRACE_FL_GRAPH_BIT,
648 };
649 
650 static inline void set_tsk_trace_trace(struct task_struct *tsk)
651 {
652 	set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
653 }
654 
655 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
656 {
657 	clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
658 }
659 
660 static inline int test_tsk_trace_trace(struct task_struct *tsk)
661 {
662 	return tsk->trace & TSK_TRACE_FL_TRACE;
663 }
664 
665 static inline void set_tsk_trace_graph(struct task_struct *tsk)
666 {
667 	set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
668 }
669 
670 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
671 {
672 	clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
673 }
674 
675 static inline int test_tsk_trace_graph(struct task_struct *tsk)
676 {
677 	return tsk->trace & TSK_TRACE_FL_GRAPH;
678 }
679 
680 enum ftrace_dump_mode;
681 
682 extern enum ftrace_dump_mode ftrace_dump_on_oops;
683 
684 #ifdef CONFIG_PREEMPT
685 #define INIT_TRACE_RECURSION		.trace_recursion = 0,
686 #endif
687 
688 #endif /* CONFIG_TRACING */
689 
690 #ifndef INIT_TRACE_RECURSION
691 #define INIT_TRACE_RECURSION
692 #endif
693 
694 #ifdef CONFIG_FTRACE_SYSCALLS
695 
696 unsigned long arch_syscall_addr(int nr);
697 
698 #endif /* CONFIG_FTRACE_SYSCALLS */
699 
700 #endif /* _LINUX_FTRACE_H */
701