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TOMOYO Linux Cross Reference
Linux/include/linux/ftrace.h

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  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/ptrace.h>
 14 #include <linux/ktime.h>
 15 #include <linux/sched.h>
 16 #include <linux/types.h>
 17 #include <linux/init.h>
 18 #include <linux/fs.h>
 19 
 20 #include <asm/ftrace.h>
 21 
 22 /*
 23  * If the arch supports passing the variable contents of
 24  * function_trace_op as the third parameter back from the
 25  * mcount call, then the arch should define this as 1.
 26  */
 27 #ifndef ARCH_SUPPORTS_FTRACE_OPS
 28 #define ARCH_SUPPORTS_FTRACE_OPS 0
 29 #endif
 30 
 31 /*
 32  * If the arch's mcount caller does not support all of ftrace's
 33  * features, then it must call an indirect function that
 34  * does. Or at least does enough to prevent any unwelcomed side effects.
 35  */
 36 #if !ARCH_SUPPORTS_FTRACE_OPS
 37 # define FTRACE_FORCE_LIST_FUNC 1
 38 #else
 39 # define FTRACE_FORCE_LIST_FUNC 0
 40 #endif
 41 
 42 /* Main tracing buffer and events set up */
 43 #ifdef CONFIG_TRACING
 44 void trace_init(void);
 45 #else
 46 static inline void trace_init(void) { }
 47 #endif
 48 
 49 struct module;
 50 struct ftrace_hash;
 51 
 52 #ifdef CONFIG_FUNCTION_TRACER
 53 
 54 extern int ftrace_enabled;
 55 extern int
 56 ftrace_enable_sysctl(struct ctl_table *table, int write,
 57                      void __user *buffer, size_t *lenp,
 58                      loff_t *ppos);
 59 
 60 struct ftrace_ops;
 61 
 62 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
 63                               struct ftrace_ops *op, struct pt_regs *regs);
 64 
 65 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
 66 
 67 /*
 68  * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
 69  * set in the flags member.
 70  * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and
 71  * IPMODIFY are a kind of attribute flags which can be set only before
 72  * registering the ftrace_ops, and can not be modified while registered.
 73  * Changing those attribute flags after regsitering ftrace_ops will
 74  * cause unexpected results.
 75  *
 76  * ENABLED - set/unset when ftrace_ops is registered/unregistered
 77  * DYNAMIC - set when ftrace_ops is registered to denote dynamically
 78  *           allocated ftrace_ops which need special care
 79  * CONTROL - set manualy by ftrace_ops user to denote the ftrace_ops
 80  *           could be controled by following calls:
 81  *             ftrace_function_local_enable
 82  *             ftrace_function_local_disable
 83  * SAVE_REGS - The ftrace_ops wants regs saved at each function called
 84  *            and passed to the callback. If this flag is set, but the
 85  *            architecture does not support passing regs
 86  *            (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
 87  *            ftrace_ops will fail to register, unless the next flag
 88  *            is set.
 89  * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
 90  *            handler can handle an arch that does not save regs
 91  *            (the handler tests if regs == NULL), then it can set
 92  *            this flag instead. It will not fail registering the ftrace_ops
 93  *            but, the regs field will be NULL if the arch does not support
 94  *            passing regs to the handler.
 95  *            Note, if this flag is set, the SAVE_REGS flag will automatically
 96  *            get set upon registering the ftrace_ops, if the arch supports it.
 97  * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
 98  *            that the call back has its own recursion protection. If it does
 99  *            not set this, then the ftrace infrastructure will add recursion
100  *            protection for the caller.
101  * STUB   - The ftrace_ops is just a place holder.
102  * INITIALIZED - The ftrace_ops has already been initialized (first use time
103  *            register_ftrace_function() is called, it will initialized the ops)
104  * DELETED - The ops are being deleted, do not let them be registered again.
105  * ADDING  - The ops is in the process of being added.
106  * REMOVING - The ops is in the process of being removed.
107  * MODIFYING - The ops is in the process of changing its filter functions.
108  * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
109  *            The arch specific code sets this flag when it allocated a
110  *            trampoline. This lets the arch know that it can update the
111  *            trampoline in case the callback function changes.
112  *            The ftrace_ops trampoline can be set by the ftrace users, and
113  *            in such cases the arch must not modify it. Only the arch ftrace
114  *            core code should set this flag.
115  * IPMODIFY - The ops can modify the IP register. This can only be set with
116  *            SAVE_REGS. If another ops with this flag set is already registered
117  *            for any of the functions that this ops will be registered for, then
118  *            this ops will fail to register or set_filter_ip.
119  * PID     - Is affected by set_ftrace_pid (allows filtering on those pids)
120  */
121 enum {
122         FTRACE_OPS_FL_ENABLED                   = 1 << 0,
123         FTRACE_OPS_FL_DYNAMIC                   = 1 << 1,
124         FTRACE_OPS_FL_CONTROL                   = 1 << 2,
125         FTRACE_OPS_FL_SAVE_REGS                 = 1 << 3,
126         FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED    = 1 << 4,
127         FTRACE_OPS_FL_RECURSION_SAFE            = 1 << 5,
128         FTRACE_OPS_FL_STUB                      = 1 << 6,
129         FTRACE_OPS_FL_INITIALIZED               = 1 << 7,
130         FTRACE_OPS_FL_DELETED                   = 1 << 8,
131         FTRACE_OPS_FL_ADDING                    = 1 << 9,
132         FTRACE_OPS_FL_REMOVING                  = 1 << 10,
133         FTRACE_OPS_FL_MODIFYING                 = 1 << 11,
134         FTRACE_OPS_FL_ALLOC_TRAMP               = 1 << 12,
135         FTRACE_OPS_FL_IPMODIFY                  = 1 << 13,
136         FTRACE_OPS_FL_PID                       = 1 << 14,
137 };
138 
139 #ifdef CONFIG_DYNAMIC_FTRACE
140 /* The hash used to know what functions callbacks trace */
141 struct ftrace_ops_hash {
142         struct ftrace_hash              *notrace_hash;
143         struct ftrace_hash              *filter_hash;
144         struct mutex                    regex_lock;
145 };
146 #endif
147 
148 /*
149  * Note, ftrace_ops can be referenced outside of RCU protection.
150  * (Although, for perf, the control ops prevent that). If ftrace_ops is
151  * allocated and not part of kernel core data, the unregistering of it will
152  * perform a scheduling on all CPUs to make sure that there are no more users.
153  * Depending on the load of the system that may take a bit of time.
154  *
155  * Any private data added must also take care not to be freed and if private
156  * data is added to a ftrace_ops that is in core code, the user of the
157  * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
158  */
159 struct ftrace_ops {
160         ftrace_func_t                   func;
161         struct ftrace_ops               *next;
162         unsigned long                   flags;
163         void                            *private;
164         ftrace_func_t                   saved_func;
165         int __percpu                    *disabled;
166 #ifdef CONFIG_DYNAMIC_FTRACE
167         int                             nr_trampolines;
168         struct ftrace_ops_hash          local_hash;
169         struct ftrace_ops_hash          *func_hash;
170         struct ftrace_ops_hash          old_hash;
171         unsigned long                   trampoline;
172         unsigned long                   trampoline_size;
173 #endif
174 };
175 
176 /*
177  * Type of the current tracing.
178  */
179 enum ftrace_tracing_type_t {
180         FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
181         FTRACE_TYPE_RETURN,     /* Hook the return of the function */
182 };
183 
184 /* Current tracing type, default is FTRACE_TYPE_ENTER */
185 extern enum ftrace_tracing_type_t ftrace_tracing_type;
186 
187 /*
188  * The ftrace_ops must be a static and should also
189  * be read_mostly.  These functions do modify read_mostly variables
190  * so use them sparely. Never free an ftrace_op or modify the
191  * next pointer after it has been registered. Even after unregistering
192  * it, the next pointer may still be used internally.
193  */
194 int register_ftrace_function(struct ftrace_ops *ops);
195 int unregister_ftrace_function(struct ftrace_ops *ops);
196 void clear_ftrace_function(void);
197 
198 /**
199  * ftrace_function_local_enable - enable controlled ftrace_ops on current cpu
200  *
201  * This function enables tracing on current cpu by decreasing
202  * the per cpu control variable.
203  * It must be called with preemption disabled and only on ftrace_ops
204  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
205  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
206  */
207 static inline void ftrace_function_local_enable(struct ftrace_ops *ops)
208 {
209         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
210                 return;
211 
212         (*this_cpu_ptr(ops->disabled))--;
213 }
214 
215 /**
216  * ftrace_function_local_disable - enable controlled ftrace_ops on current cpu
217  *
218  * This function enables tracing on current cpu by decreasing
219  * the per cpu control variable.
220  * It must be called with preemption disabled and only on ftrace_ops
221  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
222  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
223  */
224 static inline void ftrace_function_local_disable(struct ftrace_ops *ops)
225 {
226         if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL)))
227                 return;
228 
229         (*this_cpu_ptr(ops->disabled))++;
230 }
231 
232 /**
233  * ftrace_function_local_disabled - returns ftrace_ops disabled value
234  *                                  on current cpu
235  *
236  * This function returns value of ftrace_ops::disabled on current cpu.
237  * It must be called with preemption disabled and only on ftrace_ops
238  * registered with FTRACE_OPS_FL_CONTROL. If called without preemption
239  * disabled, this_cpu_ptr will complain when CONFIG_DEBUG_PREEMPT is enabled.
240  */
241 static inline int ftrace_function_local_disabled(struct ftrace_ops *ops)
242 {
243         WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_CONTROL));
244         return *this_cpu_ptr(ops->disabled);
245 }
246 
247 extern void ftrace_stub(unsigned long a0, unsigned long a1,
248                         struct ftrace_ops *op, struct pt_regs *regs);
249 
250 #else /* !CONFIG_FUNCTION_TRACER */
251 /*
252  * (un)register_ftrace_function must be a macro since the ops parameter
253  * must not be evaluated.
254  */
255 #define register_ftrace_function(ops) ({ 0; })
256 #define unregister_ftrace_function(ops) ({ 0; })
257 static inline int ftrace_nr_registered_ops(void)
258 {
259         return 0;
260 }
261 static inline void clear_ftrace_function(void) { }
262 static inline void ftrace_kill(void) { }
263 #endif /* CONFIG_FUNCTION_TRACER */
264 
265 #ifdef CONFIG_STACK_TRACER
266 extern int stack_tracer_enabled;
267 int
268 stack_trace_sysctl(struct ctl_table *table, int write,
269                    void __user *buffer, size_t *lenp,
270                    loff_t *ppos);
271 #endif
272 
273 struct ftrace_func_command {
274         struct list_head        list;
275         char                    *name;
276         int                     (*func)(struct ftrace_hash *hash,
277                                         char *func, char *cmd,
278                                         char *params, int enable);
279 };
280 
281 #ifdef CONFIG_DYNAMIC_FTRACE
282 
283 int ftrace_arch_code_modify_prepare(void);
284 int ftrace_arch_code_modify_post_process(void);
285 
286 struct dyn_ftrace;
287 
288 void ftrace_bug(int err, struct dyn_ftrace *rec);
289 
290 struct seq_file;
291 
292 struct ftrace_probe_ops {
293         void                    (*func)(unsigned long ip,
294                                         unsigned long parent_ip,
295                                         void **data);
296         int                     (*init)(struct ftrace_probe_ops *ops,
297                                         unsigned long ip, void **data);
298         void                    (*free)(struct ftrace_probe_ops *ops,
299                                         unsigned long ip, void **data);
300         int                     (*print)(struct seq_file *m,
301                                          unsigned long ip,
302                                          struct ftrace_probe_ops *ops,
303                                          void *data);
304 };
305 
306 extern int
307 register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
308                               void *data);
309 extern void
310 unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
311                                 void *data);
312 extern void
313 unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
314 extern void unregister_ftrace_function_probe_all(char *glob);
315 
316 extern int ftrace_text_reserved(const void *start, const void *end);
317 
318 extern int ftrace_nr_registered_ops(void);
319 
320 bool is_ftrace_trampoline(unsigned long addr);
321 
322 /*
323  * The dyn_ftrace record's flags field is split into two parts.
324  * the first part which is '0-FTRACE_REF_MAX' is a counter of
325  * the number of callbacks that have registered the function that
326  * the dyn_ftrace descriptor represents.
327  *
328  * The second part is a mask:
329  *  ENABLED - the function is being traced
330  *  REGS    - the record wants the function to save regs
331  *  REGS_EN - the function is set up to save regs.
332  *  IPMODIFY - the record allows for the IP address to be changed.
333  *
334  * When a new ftrace_ops is registered and wants a function to save
335  * pt_regs, the rec->flag REGS is set. When the function has been
336  * set up to save regs, the REG_EN flag is set. Once a function
337  * starts saving regs it will do so until all ftrace_ops are removed
338  * from tracing that function.
339  */
340 enum {
341         FTRACE_FL_ENABLED       = (1UL << 31),
342         FTRACE_FL_REGS          = (1UL << 30),
343         FTRACE_FL_REGS_EN       = (1UL << 29),
344         FTRACE_FL_TRAMP         = (1UL << 28),
345         FTRACE_FL_TRAMP_EN      = (1UL << 27),
346         FTRACE_FL_IPMODIFY      = (1UL << 26),
347 };
348 
349 #define FTRACE_REF_MAX_SHIFT    26
350 #define FTRACE_FL_BITS          6
351 #define FTRACE_FL_MASKED_BITS   ((1UL << FTRACE_FL_BITS) - 1)
352 #define FTRACE_FL_MASK          (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
353 #define FTRACE_REF_MAX          ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
354 
355 #define ftrace_rec_count(rec)   ((rec)->flags & ~FTRACE_FL_MASK)
356 
357 struct dyn_ftrace {
358         unsigned long           ip; /* address of mcount call-site */
359         unsigned long           flags;
360         struct dyn_arch_ftrace  arch;
361 };
362 
363 int ftrace_force_update(void);
364 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
365                          int remove, int reset);
366 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
367                        int len, int reset);
368 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
369                         int len, int reset);
370 void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
371 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
372 void ftrace_free_filter(struct ftrace_ops *ops);
373 
374 int register_ftrace_command(struct ftrace_func_command *cmd);
375 int unregister_ftrace_command(struct ftrace_func_command *cmd);
376 
377 enum {
378         FTRACE_UPDATE_CALLS             = (1 << 0),
379         FTRACE_DISABLE_CALLS            = (1 << 1),
380         FTRACE_UPDATE_TRACE_FUNC        = (1 << 2),
381         FTRACE_START_FUNC_RET           = (1 << 3),
382         FTRACE_STOP_FUNC_RET            = (1 << 4),
383 };
384 
385 /*
386  * The FTRACE_UPDATE_* enum is used to pass information back
387  * from the ftrace_update_record() and ftrace_test_record()
388  * functions. These are called by the code update routines
389  * to find out what is to be done for a given function.
390  *
391  *  IGNORE           - The function is already what we want it to be
392  *  MAKE_CALL        - Start tracing the function
393  *  MODIFY_CALL      - Stop saving regs for the function
394  *  MAKE_NOP         - Stop tracing the function
395  */
396 enum {
397         FTRACE_UPDATE_IGNORE,
398         FTRACE_UPDATE_MAKE_CALL,
399         FTRACE_UPDATE_MODIFY_CALL,
400         FTRACE_UPDATE_MAKE_NOP,
401 };
402 
403 enum {
404         FTRACE_ITER_FILTER      = (1 << 0),
405         FTRACE_ITER_NOTRACE     = (1 << 1),
406         FTRACE_ITER_PRINTALL    = (1 << 2),
407         FTRACE_ITER_DO_HASH     = (1 << 3),
408         FTRACE_ITER_HASH        = (1 << 4),
409         FTRACE_ITER_ENABLED     = (1 << 5),
410 };
411 
412 void arch_ftrace_update_code(int command);
413 
414 struct ftrace_rec_iter;
415 
416 struct ftrace_rec_iter *ftrace_rec_iter_start(void);
417 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
418 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
419 
420 #define for_ftrace_rec_iter(iter)               \
421         for (iter = ftrace_rec_iter_start();    \
422              iter;                              \
423              iter = ftrace_rec_iter_next(iter))
424 
425 
426 int ftrace_update_record(struct dyn_ftrace *rec, int enable);
427 int ftrace_test_record(struct dyn_ftrace *rec, int enable);
428 void ftrace_run_stop_machine(int command);
429 unsigned long ftrace_location(unsigned long ip);
430 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
431 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
432 
433 extern ftrace_func_t ftrace_trace_function;
434 
435 int ftrace_regex_open(struct ftrace_ops *ops, int flag,
436                   struct inode *inode, struct file *file);
437 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
438                             size_t cnt, loff_t *ppos);
439 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
440                              size_t cnt, loff_t *ppos);
441 int ftrace_regex_release(struct inode *inode, struct file *file);
442 
443 void __init
444 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
445 
446 /* defined in arch */
447 extern int ftrace_ip_converted(unsigned long ip);
448 extern int ftrace_dyn_arch_init(void);
449 extern void ftrace_replace_code(int enable);
450 extern int ftrace_update_ftrace_func(ftrace_func_t func);
451 extern void ftrace_caller(void);
452 extern void ftrace_regs_caller(void);
453 extern void ftrace_call(void);
454 extern void ftrace_regs_call(void);
455 extern void mcount_call(void);
456 
457 void ftrace_modify_all_code(int command);
458 
459 #ifndef FTRACE_ADDR
460 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
461 #endif
462 
463 #ifndef FTRACE_GRAPH_ADDR
464 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
465 #endif
466 
467 #ifndef FTRACE_REGS_ADDR
468 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
469 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
470 #else
471 # define FTRACE_REGS_ADDR FTRACE_ADDR
472 #endif
473 #endif
474 
475 /*
476  * If an arch would like functions that are only traced
477  * by the function graph tracer to jump directly to its own
478  * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
479  * to be that address to jump to.
480  */
481 #ifndef FTRACE_GRAPH_TRAMP_ADDR
482 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
483 #endif
484 
485 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
486 extern void ftrace_graph_caller(void);
487 extern int ftrace_enable_ftrace_graph_caller(void);
488 extern int ftrace_disable_ftrace_graph_caller(void);
489 #else
490 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
491 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
492 #endif
493 
494 /**
495  * ftrace_make_nop - convert code into nop
496  * @mod: module structure if called by module load initialization
497  * @rec: the mcount call site record
498  * @addr: the address that the call site should be calling
499  *
500  * This is a very sensitive operation and great care needs
501  * to be taken by the arch.  The operation should carefully
502  * read the location, check to see if what is read is indeed
503  * what we expect it to be, and then on success of the compare,
504  * it should write to the location.
505  *
506  * The code segment at @rec->ip should be a caller to @addr
507  *
508  * Return must be:
509  *  0 on success
510  *  -EFAULT on error reading the location
511  *  -EINVAL on a failed compare of the contents
512  *  -EPERM  on error writing to the location
513  * Any other value will be considered a failure.
514  */
515 extern int ftrace_make_nop(struct module *mod,
516                            struct dyn_ftrace *rec, unsigned long addr);
517 
518 /**
519  * ftrace_make_call - convert a nop call site into a call to addr
520  * @rec: the mcount call site record
521  * @addr: the address that the call site should call
522  *
523  * This is a very sensitive operation and great care needs
524  * to be taken by the arch.  The operation should carefully
525  * read the location, check to see if what is read is indeed
526  * what we expect it to be, and then on success of the compare,
527  * it should write to the location.
528  *
529  * The code segment at @rec->ip should be a nop
530  *
531  * Return must be:
532  *  0 on success
533  *  -EFAULT on error reading the location
534  *  -EINVAL on a failed compare of the contents
535  *  -EPERM  on error writing to the location
536  * Any other value will be considered a failure.
537  */
538 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
539 
540 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
541 /**
542  * ftrace_modify_call - convert from one addr to another (no nop)
543  * @rec: the mcount call site record
544  * @old_addr: the address expected to be currently called to
545  * @addr: the address to change to
546  *
547  * This is a very sensitive operation and great care needs
548  * to be taken by the arch.  The operation should carefully
549  * read the location, check to see if what is read is indeed
550  * what we expect it to be, and then on success of the compare,
551  * it should write to the location.
552  *
553  * The code segment at @rec->ip should be a caller to @old_addr
554  *
555  * Return must be:
556  *  0 on success
557  *  -EFAULT on error reading the location
558  *  -EINVAL on a failed compare of the contents
559  *  -EPERM  on error writing to the location
560  * Any other value will be considered a failure.
561  */
562 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
563                               unsigned long addr);
564 #else
565 /* Should never be called */
566 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
567                                      unsigned long addr)
568 {
569         return -EINVAL;
570 }
571 #endif
572 
573 /* May be defined in arch */
574 extern int ftrace_arch_read_dyn_info(char *buf, int size);
575 
576 extern int skip_trace(unsigned long ip);
577 extern void ftrace_module_init(struct module *mod);
578 
579 extern void ftrace_disable_daemon(void);
580 extern void ftrace_enable_daemon(void);
581 #else /* CONFIG_DYNAMIC_FTRACE */
582 static inline int skip_trace(unsigned long ip) { return 0; }
583 static inline int ftrace_force_update(void) { return 0; }
584 static inline void ftrace_disable_daemon(void) { }
585 static inline void ftrace_enable_daemon(void) { }
586 static inline void ftrace_release_mod(struct module *mod) {}
587 static inline void ftrace_module_init(struct module *mod) {}
588 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
589 {
590         return -EINVAL;
591 }
592 static inline __init int unregister_ftrace_command(char *cmd_name)
593 {
594         return -EINVAL;
595 }
596 static inline int ftrace_text_reserved(const void *start, const void *end)
597 {
598         return 0;
599 }
600 static inline unsigned long ftrace_location(unsigned long ip)
601 {
602         return 0;
603 }
604 
605 /*
606  * Again users of functions that have ftrace_ops may not
607  * have them defined when ftrace is not enabled, but these
608  * functions may still be called. Use a macro instead of inline.
609  */
610 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
611 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
612 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
613 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
614 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
615 #define ftrace_free_filter(ops) do { } while (0)
616 
617 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
618                             size_t cnt, loff_t *ppos) { return -ENODEV; }
619 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
620                              size_t cnt, loff_t *ppos) { return -ENODEV; }
621 static inline int
622 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
623 
624 static inline bool is_ftrace_trampoline(unsigned long addr)
625 {
626         return false;
627 }
628 #endif /* CONFIG_DYNAMIC_FTRACE */
629 
630 /* totally disable ftrace - can not re-enable after this */
631 void ftrace_kill(void);
632 
633 static inline void tracer_disable(void)
634 {
635 #ifdef CONFIG_FUNCTION_TRACER
636         ftrace_enabled = 0;
637 #endif
638 }
639 
640 /*
641  * Ftrace disable/restore without lock. Some synchronization mechanism
642  * must be used to prevent ftrace_enabled to be changed between
643  * disable/restore.
644  */
645 static inline int __ftrace_enabled_save(void)
646 {
647 #ifdef CONFIG_FUNCTION_TRACER
648         int saved_ftrace_enabled = ftrace_enabled;
649         ftrace_enabled = 0;
650         return saved_ftrace_enabled;
651 #else
652         return 0;
653 #endif
654 }
655 
656 static inline void __ftrace_enabled_restore(int enabled)
657 {
658 #ifdef CONFIG_FUNCTION_TRACER
659         ftrace_enabled = enabled;
660 #endif
661 }
662 
663 /* All archs should have this, but we define it for consistency */
664 #ifndef ftrace_return_address0
665 # define ftrace_return_address0 __builtin_return_address(0)
666 #endif
667 
668 /* Archs may use other ways for ADDR1 and beyond */
669 #ifndef ftrace_return_address
670 # ifdef CONFIG_FRAME_POINTER
671 #  define ftrace_return_address(n) __builtin_return_address(n)
672 # else
673 #  define ftrace_return_address(n) 0UL
674 # endif
675 #endif
676 
677 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
678 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
679 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
680 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
681 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
682 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
683 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
684 
685 #ifdef CONFIG_IRQSOFF_TRACER
686   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
687   extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
688 #else
689   static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
690   static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
691 #endif
692 
693 #ifdef CONFIG_PREEMPT_TRACER
694   extern void trace_preempt_on(unsigned long a0, unsigned long a1);
695   extern void trace_preempt_off(unsigned long a0, unsigned long a1);
696 #else
697 /*
698  * Use defines instead of static inlines because some arches will make code out
699  * of the CALLER_ADDR, when we really want these to be a real nop.
700  */
701 # define trace_preempt_on(a0, a1) do { } while (0)
702 # define trace_preempt_off(a0, a1) do { } while (0)
703 #endif
704 
705 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
706 extern void ftrace_init(void);
707 #else
708 static inline void ftrace_init(void) { }
709 #endif
710 
711 /*
712  * Structure that defines an entry function trace.
713  */
714 struct ftrace_graph_ent {
715         unsigned long func; /* Current function */
716         int depth;
717 };
718 
719 /*
720  * Structure that defines a return function trace.
721  */
722 struct ftrace_graph_ret {
723         unsigned long func; /* Current function */
724         unsigned long long calltime;
725         unsigned long long rettime;
726         /* Number of functions that overran the depth limit for current task */
727         unsigned long overrun;
728         int depth;
729 };
730 
731 /* Type of the callback handlers for tracing function graph*/
732 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
733 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
734 
735 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
736 
737 /* for init task */
738 #define INIT_FTRACE_GRAPH               .ret_stack = NULL,
739 
740 /*
741  * Stack of return addresses for functions
742  * of a thread.
743  * Used in struct thread_info
744  */
745 struct ftrace_ret_stack {
746         unsigned long ret;
747         unsigned long func;
748         unsigned long long calltime;
749         unsigned long long subtime;
750         unsigned long fp;
751 };
752 
753 /*
754  * Primary handler of a function return.
755  * It relays on ftrace_return_to_handler.
756  * Defined in entry_32/64.S
757  */
758 extern void return_to_handler(void);
759 
760 extern int
761 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
762                          unsigned long frame_pointer);
763 
764 /*
765  * Sometimes we don't want to trace a function with the function
766  * graph tracer but we want them to keep traced by the usual function
767  * tracer if the function graph tracer is not configured.
768  */
769 #define __notrace_funcgraph             notrace
770 
771 /*
772  * We want to which function is an entrypoint of a hardirq.
773  * That will help us to put a signal on output.
774  */
775 #define __irq_entry              __attribute__((__section__(".irqentry.text")))
776 
777 /* Limits of hardirq entrypoints */
778 extern char __irqentry_text_start[];
779 extern char __irqentry_text_end[];
780 
781 #define FTRACE_NOTRACE_DEPTH 65536
782 #define FTRACE_RETFUNC_DEPTH 50
783 #define FTRACE_RETSTACK_ALLOC_SIZE 32
784 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
785                                 trace_func_graph_ent_t entryfunc);
786 
787 extern bool ftrace_graph_is_dead(void);
788 extern void ftrace_graph_stop(void);
789 
790 /* The current handlers in use */
791 extern trace_func_graph_ret_t ftrace_graph_return;
792 extern trace_func_graph_ent_t ftrace_graph_entry;
793 
794 extern void unregister_ftrace_graph(void);
795 
796 extern void ftrace_graph_init_task(struct task_struct *t);
797 extern void ftrace_graph_exit_task(struct task_struct *t);
798 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
799 
800 static inline int task_curr_ret_stack(struct task_struct *t)
801 {
802         return t->curr_ret_stack;
803 }
804 
805 static inline void pause_graph_tracing(void)
806 {
807         atomic_inc(&current->tracing_graph_pause);
808 }
809 
810 static inline void unpause_graph_tracing(void)
811 {
812         atomic_dec(&current->tracing_graph_pause);
813 }
814 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */
815 
816 #define __notrace_funcgraph
817 #define __irq_entry
818 #define INIT_FTRACE_GRAPH
819 
820 static inline void ftrace_graph_init_task(struct task_struct *t) { }
821 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
822 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
823 
824 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
825                           trace_func_graph_ent_t entryfunc)
826 {
827         return -1;
828 }
829 static inline void unregister_ftrace_graph(void) { }
830 
831 static inline int task_curr_ret_stack(struct task_struct *tsk)
832 {
833         return -1;
834 }
835 
836 static inline void pause_graph_tracing(void) { }
837 static inline void unpause_graph_tracing(void) { }
838 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
839 
840 #ifdef CONFIG_TRACING
841 
842 /* flags for current->trace */
843 enum {
844         TSK_TRACE_FL_TRACE_BIT  = 0,
845         TSK_TRACE_FL_GRAPH_BIT  = 1,
846 };
847 enum {
848         TSK_TRACE_FL_TRACE      = 1 << TSK_TRACE_FL_TRACE_BIT,
849         TSK_TRACE_FL_GRAPH      = 1 << TSK_TRACE_FL_GRAPH_BIT,
850 };
851 
852 static inline void set_tsk_trace_trace(struct task_struct *tsk)
853 {
854         set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
855 }
856 
857 static inline void clear_tsk_trace_trace(struct task_struct *tsk)
858 {
859         clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
860 }
861 
862 static inline int test_tsk_trace_trace(struct task_struct *tsk)
863 {
864         return tsk->trace & TSK_TRACE_FL_TRACE;
865 }
866 
867 static inline void set_tsk_trace_graph(struct task_struct *tsk)
868 {
869         set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
870 }
871 
872 static inline void clear_tsk_trace_graph(struct task_struct *tsk)
873 {
874         clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
875 }
876 
877 static inline int test_tsk_trace_graph(struct task_struct *tsk)
878 {
879         return tsk->trace & TSK_TRACE_FL_GRAPH;
880 }
881 
882 enum ftrace_dump_mode;
883 
884 extern enum ftrace_dump_mode ftrace_dump_on_oops;
885 extern int tracepoint_printk;
886 
887 extern void disable_trace_on_warning(void);
888 extern int __disable_trace_on_warning;
889 
890 #ifdef CONFIG_PREEMPT
891 #define INIT_TRACE_RECURSION            .trace_recursion = 0,
892 #endif
893 
894 #else /* CONFIG_TRACING */
895 static inline void  disable_trace_on_warning(void) { }
896 #endif /* CONFIG_TRACING */
897 
898 #ifndef INIT_TRACE_RECURSION
899 #define INIT_TRACE_RECURSION
900 #endif
901 
902 #ifdef CONFIG_FTRACE_SYSCALLS
903 
904 unsigned long arch_syscall_addr(int nr);
905 
906 #endif /* CONFIG_FTRACE_SYSCALLS */
907 
908 #endif /* _LINUX_FTRACE_H */
909 

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