Merge commit 'perf/core' into perf/hw-breakpoint
[linux-3.10.git] / kernel / trace / trace.h
1 #ifndef _LINUX_KERNEL_TRACE_H
2 #define _LINUX_KERNEL_TRACE_H
3
4 #include <linux/fs.h>
5 #include <asm/atomic.h>
6 #include <linux/sched.h>
7 #include <linux/clocksource.h>
8 #include <linux/ring_buffer.h>
9 #include <linux/mmiotrace.h>
10 #include <linux/tracepoint.h>
11 #include <linux/ftrace.h>
12 #include <trace/boot.h>
13 #include <linux/kmemtrace.h>
14
15 #include <linux/trace_seq.h>
16 #include <linux/ftrace_event.h>
17
18 #ifdef CONFIG_KSYM_TRACER
19 #include <asm/hw_breakpoint.h>
20 #endif
21
22 enum trace_type {
23         __TRACE_FIRST_TYPE = 0,
24
25         TRACE_FN,
26         TRACE_CTX,
27         TRACE_WAKE,
28         TRACE_STACK,
29         TRACE_PRINT,
30         TRACE_BPRINT,
31         TRACE_SPECIAL,
32         TRACE_MMIO_RW,
33         TRACE_MMIO_MAP,
34         TRACE_BRANCH,
35         TRACE_BOOT_CALL,
36         TRACE_BOOT_RET,
37         TRACE_GRAPH_RET,
38         TRACE_GRAPH_ENT,
39         TRACE_USER_STACK,
40         TRACE_HW_BRANCHES,
41         TRACE_KMEM_ALLOC,
42         TRACE_KMEM_FREE,
43         TRACE_BLK,
44         TRACE_KSYM,
45
46         __TRACE_LAST_TYPE,
47 };
48
49 enum kmemtrace_type_id {
50         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
51         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
52         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
53 };
54
55 extern struct tracer boot_tracer;
56
57 #undef __field
58 #define __field(type, item)             type    item;
59
60 #undef __field_struct
61 #define __field_struct(type, item)      __field(type, item)
62
63 #undef __field_desc
64 #define __field_desc(type, container, item)
65
66 #undef __array
67 #define __array(type, item, size)       type    item[size];
68
69 #undef __array_desc
70 #define __array_desc(type, container, item, size)
71
72 #undef __dynamic_array
73 #define __dynamic_array(type, item)     type    item[];
74
75 #undef F_STRUCT
76 #define F_STRUCT(args...)               args
77
78 #undef FTRACE_ENTRY
79 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)     \
80         struct struct_name {                                    \
81                 struct trace_entry      ent;                    \
82                 tstruct                                         \
83         }
84
85 #undef TP_ARGS
86 #define TP_ARGS(args...)        args
87
88 #undef FTRACE_ENTRY_DUP
89 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
90
91 #include "trace_entries.h"
92
93 /*
94  * syscalls are special, and need special handling, this is why
95  * they are not included in trace_entries.h
96  */
97 struct syscall_trace_enter {
98         struct trace_entry      ent;
99         int                     nr;
100         unsigned long           args[];
101 };
102
103 struct syscall_trace_exit {
104         struct trace_entry      ent;
105         int                     nr;
106         unsigned long           ret;
107 };
108
109 /*
110  * trace_flag_type is an enumeration that holds different
111  * states when a trace occurs. These are:
112  *  IRQS_OFF            - interrupts were disabled
113  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
114  *  NEED_RESCHED        - reschedule is requested
115  *  HARDIRQ             - inside an interrupt handler
116  *  SOFTIRQ             - inside a softirq handler
117  */
118 enum trace_flag_type {
119         TRACE_FLAG_IRQS_OFF             = 0x01,
120         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
121         TRACE_FLAG_NEED_RESCHED         = 0x04,
122         TRACE_FLAG_HARDIRQ              = 0x08,
123         TRACE_FLAG_SOFTIRQ              = 0x10,
124 };
125
126 #define TRACE_BUF_SIZE          1024
127
128 /*
129  * The CPU trace array - it consists of thousands of trace entries
130  * plus some other descriptor data: (for example which task started
131  * the trace, etc.)
132  */
133 struct trace_array_cpu {
134         atomic_t                disabled;
135         void                    *buffer_page;   /* ring buffer spare */
136
137         unsigned long           saved_latency;
138         unsigned long           critical_start;
139         unsigned long           critical_end;
140         unsigned long           critical_sequence;
141         unsigned long           nice;
142         unsigned long           policy;
143         unsigned long           rt_priority;
144         unsigned long           skipped_entries;
145         cycle_t                 preempt_timestamp;
146         pid_t                   pid;
147         uid_t                   uid;
148         char                    comm[TASK_COMM_LEN];
149 };
150
151 /*
152  * The trace array - an array of per-CPU trace arrays. This is the
153  * highest level data structure that individual tracers deal with.
154  * They have on/off state as well:
155  */
156 struct trace_array {
157         struct ring_buffer      *buffer;
158         unsigned long           entries;
159         int                     cpu;
160         cycle_t                 time_start;
161         struct task_struct      *waiter;
162         struct trace_array_cpu  *data[NR_CPUS];
163 };
164
165 #define FTRACE_CMP_TYPE(var, type) \
166         __builtin_types_compatible_p(typeof(var), type *)
167
168 #undef IF_ASSIGN
169 #define IF_ASSIGN(var, entry, etype, id)                \
170         if (FTRACE_CMP_TYPE(var, etype)) {              \
171                 var = (typeof(var))(entry);             \
172                 WARN_ON(id && (entry)->type != id);     \
173                 break;                                  \
174         }
175
176 /* Will cause compile errors if type is not found. */
177 extern void __ftrace_bad_type(void);
178
179 /*
180  * The trace_assign_type is a verifier that the entry type is
181  * the same as the type being assigned. To add new types simply
182  * add a line with the following format:
183  *
184  * IF_ASSIGN(var, ent, type, id);
185  *
186  *  Where "type" is the trace type that includes the trace_entry
187  *  as the "ent" item. And "id" is the trace identifier that is
188  *  used in the trace_type enum.
189  *
190  *  If the type can have more than one id, then use zero.
191  */
192 #define trace_assign_type(var, ent)                                     \
193         do {                                                            \
194                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
195                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
196                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
197                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
198                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
199                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
200                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
201                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
202                           TRACE_MMIO_RW);                               \
203                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
204                           TRACE_MMIO_MAP);                              \
205                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
206                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
207                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
208                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
209                           TRACE_GRAPH_ENT);             \
210                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
211                           TRACE_GRAPH_RET);             \
212                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
213                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
214                           TRACE_KMEM_ALLOC);    \
215                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
216                           TRACE_KMEM_FREE);     \
217                 IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\
218                 __ftrace_bad_type();                                    \
219         } while (0)
220
221 /*
222  * An option specific to a tracer. This is a boolean value.
223  * The bit is the bit index that sets its value on the
224  * flags value in struct tracer_flags.
225  */
226 struct tracer_opt {
227         const char      *name; /* Will appear on the trace_options file */
228         u32             bit; /* Mask assigned in val field in tracer_flags */
229 };
230
231 /*
232  * The set of specific options for a tracer. Your tracer
233  * have to set the initial value of the flags val.
234  */
235 struct tracer_flags {
236         u32                     val;
237         struct tracer_opt       *opts;
238 };
239
240 /* Makes more easy to define a tracer opt */
241 #define TRACER_OPT(s, b)        .name = #s, .bit = b
242
243
244 /**
245  * struct tracer - a specific tracer and its callbacks to interact with debugfs
246  * @name: the name chosen to select it on the available_tracers file
247  * @init: called when one switches to this tracer (echo name > current_tracer)
248  * @reset: called when one switches to another tracer
249  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
250  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
251  * @open: called when the trace file is opened
252  * @pipe_open: called when the trace_pipe file is opened
253  * @wait_pipe: override how the user waits for traces on trace_pipe
254  * @close: called when the trace file is released
255  * @read: override the default read callback on trace_pipe
256  * @splice_read: override the default splice_read callback on trace_pipe
257  * @selftest: selftest to run on boot (see trace_selftest.c)
258  * @print_headers: override the first lines that describe your columns
259  * @print_line: callback that prints a trace
260  * @set_flag: signals one of your private flags changed (trace_options file)
261  * @flags: your private flags
262  */
263 struct tracer {
264         const char              *name;
265         int                     (*init)(struct trace_array *tr);
266         void                    (*reset)(struct trace_array *tr);
267         void                    (*start)(struct trace_array *tr);
268         void                    (*stop)(struct trace_array *tr);
269         void                    (*open)(struct trace_iterator *iter);
270         void                    (*pipe_open)(struct trace_iterator *iter);
271         void                    (*wait_pipe)(struct trace_iterator *iter);
272         void                    (*close)(struct trace_iterator *iter);
273         ssize_t                 (*read)(struct trace_iterator *iter,
274                                         struct file *filp, char __user *ubuf,
275                                         size_t cnt, loff_t *ppos);
276         ssize_t                 (*splice_read)(struct trace_iterator *iter,
277                                                struct file *filp,
278                                                loff_t *ppos,
279                                                struct pipe_inode_info *pipe,
280                                                size_t len,
281                                                unsigned int flags);
282 #ifdef CONFIG_FTRACE_STARTUP_TEST
283         int                     (*selftest)(struct tracer *trace,
284                                             struct trace_array *tr);
285 #endif
286         void                    (*print_header)(struct seq_file *m);
287         enum print_line_t       (*print_line)(struct trace_iterator *iter);
288         /* If you handled the flag setting, return 0 */
289         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
290         struct tracer           *next;
291         int                     print_max;
292         struct tracer_flags     *flags;
293 };
294
295
296 #define TRACE_PIPE_ALL_CPU      -1
297
298 int tracer_init(struct tracer *t, struct trace_array *tr);
299 int tracing_is_enabled(void);
300 void trace_wake_up(void);
301 void tracing_reset(struct trace_array *tr, int cpu);
302 void tracing_reset_online_cpus(struct trace_array *tr);
303 void tracing_reset_current(int cpu);
304 void tracing_reset_current_online_cpus(void);
305 int tracing_open_generic(struct inode *inode, struct file *filp);
306 struct dentry *trace_create_file(const char *name,
307                                  mode_t mode,
308                                  struct dentry *parent,
309                                  void *data,
310                                  const struct file_operations *fops);
311
312 struct dentry *tracing_init_dentry(void);
313 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
314
315 struct ring_buffer_event;
316
317 struct ring_buffer_event *
318 trace_buffer_lock_reserve(struct ring_buffer *buffer,
319                           int type,
320                           unsigned long len,
321                           unsigned long flags,
322                           int pc);
323 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
324                                 struct ring_buffer_event *event,
325                                 unsigned long flags, int pc);
326
327 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
328                                                 struct trace_array_cpu *data);
329
330 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
331                                           int *ent_cpu, u64 *ent_ts);
332
333 void default_wait_pipe(struct trace_iterator *iter);
334 void poll_wait_pipe(struct trace_iterator *iter);
335
336 void ftrace(struct trace_array *tr,
337                             struct trace_array_cpu *data,
338                             unsigned long ip,
339                             unsigned long parent_ip,
340                             unsigned long flags, int pc);
341 void tracing_sched_switch_trace(struct trace_array *tr,
342                                 struct task_struct *prev,
343                                 struct task_struct *next,
344                                 unsigned long flags, int pc);
345
346 void tracing_sched_wakeup_trace(struct trace_array *tr,
347                                 struct task_struct *wakee,
348                                 struct task_struct *cur,
349                                 unsigned long flags, int pc);
350 void trace_special(struct trace_array *tr,
351                    struct trace_array_cpu *data,
352                    unsigned long arg1,
353                    unsigned long arg2,
354                    unsigned long arg3, int pc);
355 void trace_function(struct trace_array *tr,
356                     unsigned long ip,
357                     unsigned long parent_ip,
358                     unsigned long flags, int pc);
359
360 void trace_graph_return(struct ftrace_graph_ret *trace);
361 int trace_graph_entry(struct ftrace_graph_ent *trace);
362 void set_graph_array(struct trace_array *tr);
363
364 void tracing_start_cmdline_record(void);
365 void tracing_stop_cmdline_record(void);
366 void tracing_sched_switch_assign_trace(struct trace_array *tr);
367 void tracing_stop_sched_switch_record(void);
368 void tracing_start_sched_switch_record(void);
369 int register_tracer(struct tracer *type);
370 void unregister_tracer(struct tracer *type);
371 int is_tracing_stopped(void);
372
373 #define KSYM_SELFTEST_ENTRY "ksym_selftest_dummy"
374 extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr);
375
376 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
377
378 #ifdef CONFIG_TRACER_MAX_TRACE
379 extern unsigned long tracing_max_latency;
380 extern unsigned long tracing_thresh;
381
382 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
383 void update_max_tr_single(struct trace_array *tr,
384                           struct task_struct *tsk, int cpu);
385 #endif /* CONFIG_TRACER_MAX_TRACE */
386
387 #ifdef CONFIG_STACKTRACE
388 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
389                         int skip, int pc);
390
391 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
392                             int pc);
393
394 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
395                    int pc);
396 #else
397 static inline void ftrace_trace_stack(struct trace_array *tr,
398                                       unsigned long flags, int skip, int pc)
399 {
400 }
401
402 static inline void ftrace_trace_userstack(struct trace_array *tr,
403                                           unsigned long flags, int pc)
404 {
405 }
406
407 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
408                                  int skip, int pc)
409 {
410 }
411 #endif /* CONFIG_STACKTRACE */
412
413 extern cycle_t ftrace_now(int cpu);
414
415 extern void trace_find_cmdline(int pid, char comm[]);
416
417 #ifdef CONFIG_DYNAMIC_FTRACE
418 extern unsigned long ftrace_update_tot_cnt;
419 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
420 extern int DYN_FTRACE_TEST_NAME(void);
421 #endif
422
423 extern int ring_buffer_expanded;
424 extern bool tracing_selftest_disabled;
425 DECLARE_PER_CPU(local_t, ftrace_cpu_disabled);
426
427 #ifdef CONFIG_FTRACE_STARTUP_TEST
428 extern int trace_selftest_startup_function(struct tracer *trace,
429                                            struct trace_array *tr);
430 extern int trace_selftest_startup_function_graph(struct tracer *trace,
431                                                  struct trace_array *tr);
432 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
433                                           struct trace_array *tr);
434 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
435                                              struct trace_array *tr);
436 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
437                                                  struct trace_array *tr);
438 extern int trace_selftest_startup_wakeup(struct tracer *trace,
439                                          struct trace_array *tr);
440 extern int trace_selftest_startup_nop(struct tracer *trace,
441                                          struct trace_array *tr);
442 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
443                                                struct trace_array *tr);
444 extern int trace_selftest_startup_sysprof(struct tracer *trace,
445                                                struct trace_array *tr);
446 extern int trace_selftest_startup_branch(struct tracer *trace,
447                                          struct trace_array *tr);
448 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
449                                               struct trace_array *tr);
450 extern int trace_selftest_startup_ksym(struct tracer *trace,
451                                          struct trace_array *tr);
452 #endif /* CONFIG_FTRACE_STARTUP_TEST */
453
454 extern void *head_page(struct trace_array_cpu *data);
455 extern unsigned long long ns2usecs(cycle_t nsec);
456 extern int
457 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
458 extern int
459 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
460 extern int
461 trace_array_vprintk(struct trace_array *tr,
462                     unsigned long ip, const char *fmt, va_list args);
463 int trace_array_printk(struct trace_array *tr,
464                        unsigned long ip, const char *fmt, ...);
465
466 extern unsigned long trace_flags;
467
468 extern int trace_clock_id;
469
470 /* Standard output formatting function used for function return traces */
471 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
472 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
473 extern enum print_line_t
474 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
475
476 #ifdef CONFIG_DYNAMIC_FTRACE
477 /* TODO: make this variable */
478 #define FTRACE_GRAPH_MAX_FUNCS          32
479 extern int ftrace_graph_count;
480 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
481
482 static inline int ftrace_graph_addr(unsigned long addr)
483 {
484         int i;
485
486         if (!ftrace_graph_count || test_tsk_trace_graph(current))
487                 return 1;
488
489         for (i = 0; i < ftrace_graph_count; i++) {
490                 if (addr == ftrace_graph_funcs[i])
491                         return 1;
492         }
493
494         return 0;
495 }
496 #else
497 static inline int ftrace_graph_addr(unsigned long addr)
498 {
499         return 1;
500 }
501 #endif /* CONFIG_DYNAMIC_FTRACE */
502 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
503 static inline enum print_line_t
504 print_graph_function(struct trace_iterator *iter)
505 {
506         return TRACE_TYPE_UNHANDLED;
507 }
508 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
509
510 extern struct list_head ftrace_pids;
511
512 #ifdef CONFIG_FUNCTION_TRACER
513 static inline int ftrace_trace_task(struct task_struct *task)
514 {
515         if (list_empty(&ftrace_pids))
516                 return 1;
517
518         return test_tsk_trace_trace(task);
519 }
520 #else
521 static inline int ftrace_trace_task(struct task_struct *task)
522 {
523         return 1;
524 }
525 #endif
526
527 /*
528  * struct trace_parser - servers for reading the user input separated by spaces
529  * @cont: set if the input is not complete - no final space char was found
530  * @buffer: holds the parsed user input
531  * @idx: user input lenght
532  * @size: buffer size
533  */
534 struct trace_parser {
535         bool            cont;
536         char            *buffer;
537         unsigned        idx;
538         unsigned        size;
539 };
540
541 static inline bool trace_parser_loaded(struct trace_parser *parser)
542 {
543         return (parser->idx != 0);
544 }
545
546 static inline bool trace_parser_cont(struct trace_parser *parser)
547 {
548         return parser->cont;
549 }
550
551 static inline void trace_parser_clear(struct trace_parser *parser)
552 {
553         parser->cont = false;
554         parser->idx = 0;
555 }
556
557 extern int trace_parser_get_init(struct trace_parser *parser, int size);
558 extern void trace_parser_put(struct trace_parser *parser);
559 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
560         size_t cnt, loff_t *ppos);
561
562 /*
563  * trace_iterator_flags is an enumeration that defines bit
564  * positions into trace_flags that controls the output.
565  *
566  * NOTE: These bits must match the trace_options array in
567  *       trace.c.
568  */
569 enum trace_iterator_flags {
570         TRACE_ITER_PRINT_PARENT         = 0x01,
571         TRACE_ITER_SYM_OFFSET           = 0x02,
572         TRACE_ITER_SYM_ADDR             = 0x04,
573         TRACE_ITER_VERBOSE              = 0x08,
574         TRACE_ITER_RAW                  = 0x10,
575         TRACE_ITER_HEX                  = 0x20,
576         TRACE_ITER_BIN                  = 0x40,
577         TRACE_ITER_BLOCK                = 0x80,
578         TRACE_ITER_STACKTRACE           = 0x100,
579         TRACE_ITER_SCHED_TREE           = 0x200,
580         TRACE_ITER_PRINTK               = 0x400,
581         TRACE_ITER_PREEMPTONLY          = 0x800,
582         TRACE_ITER_BRANCH               = 0x1000,
583         TRACE_ITER_ANNOTATE             = 0x2000,
584         TRACE_ITER_USERSTACKTRACE       = 0x4000,
585         TRACE_ITER_SYM_USEROBJ          = 0x8000,
586         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
587         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
588         TRACE_ITER_LATENCY_FMT          = 0x40000,
589         TRACE_ITER_SLEEP_TIME           = 0x80000,
590         TRACE_ITER_GRAPH_TIME           = 0x100000,
591 };
592
593 /*
594  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
595  * control the output of kernel symbols.
596  */
597 #define TRACE_ITER_SYM_MASK \
598         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
599
600 extern struct tracer nop_trace;
601
602 /**
603  * ftrace_preempt_disable - disable preemption scheduler safe
604  *
605  * When tracing can happen inside the scheduler, there exists
606  * cases that the tracing might happen before the need_resched
607  * flag is checked. If this happens and the tracer calls
608  * preempt_enable (after a disable), a schedule might take place
609  * causing an infinite recursion.
610  *
611  * To prevent this, we read the need_resched flag before
612  * disabling preemption. When we want to enable preemption we
613  * check the flag, if it is set, then we call preempt_enable_no_resched.
614  * Otherwise, we call preempt_enable.
615  *
616  * The rational for doing the above is that if need_resched is set
617  * and we have yet to reschedule, we are either in an atomic location
618  * (where we do not need to check for scheduling) or we are inside
619  * the scheduler and do not want to resched.
620  */
621 static inline int ftrace_preempt_disable(void)
622 {
623         int resched;
624
625         resched = need_resched();
626         preempt_disable_notrace();
627
628         return resched;
629 }
630
631 /**
632  * ftrace_preempt_enable - enable preemption scheduler safe
633  * @resched: the return value from ftrace_preempt_disable
634  *
635  * This is a scheduler safe way to enable preemption and not miss
636  * any preemption checks. The disabled saved the state of preemption.
637  * If resched is set, then we are either inside an atomic or
638  * are inside the scheduler (we would have already scheduled
639  * otherwise). In this case, we do not want to call normal
640  * preempt_enable, but preempt_enable_no_resched instead.
641  */
642 static inline void ftrace_preempt_enable(int resched)
643 {
644         if (resched)
645                 preempt_enable_no_resched_notrace();
646         else
647                 preempt_enable_notrace();
648 }
649
650 #ifdef CONFIG_BRANCH_TRACER
651 extern int enable_branch_tracing(struct trace_array *tr);
652 extern void disable_branch_tracing(void);
653 static inline int trace_branch_enable(struct trace_array *tr)
654 {
655         if (trace_flags & TRACE_ITER_BRANCH)
656                 return enable_branch_tracing(tr);
657         return 0;
658 }
659 static inline void trace_branch_disable(void)
660 {
661         /* due to races, always disable */
662         disable_branch_tracing();
663 }
664 #else
665 static inline int trace_branch_enable(struct trace_array *tr)
666 {
667         return 0;
668 }
669 static inline void trace_branch_disable(void)
670 {
671 }
672 #endif /* CONFIG_BRANCH_TRACER */
673
674 /* set ring buffers to default size if not already done so */
675 int tracing_update_buffers(void);
676
677 /* trace event type bit fields, not numeric */
678 enum {
679         TRACE_EVENT_TYPE_PRINTF         = 1,
680         TRACE_EVENT_TYPE_RAW            = 2,
681 };
682
683 struct ftrace_event_field {
684         struct list_head        link;
685         char                    *name;
686         char                    *type;
687         int                     filter_type;
688         int                     offset;
689         int                     size;
690         int                     is_signed;
691 };
692
693 struct event_filter {
694         int                     n_preds;
695         struct filter_pred      **preds;
696         char                    *filter_string;
697 };
698
699 struct event_subsystem {
700         struct list_head        list;
701         const char              *name;
702         struct dentry           *entry;
703         struct event_filter     *filter;
704         int                     nr_events;
705 };
706
707 struct filter_pred;
708 struct regex;
709
710 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
711                                  int val1, int val2);
712
713 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
714
715 enum regex_type {
716         MATCH_FULL = 0,
717         MATCH_FRONT_ONLY,
718         MATCH_MIDDLE_ONLY,
719         MATCH_END_ONLY,
720 };
721
722 struct regex {
723         char                    pattern[MAX_FILTER_STR_VAL];
724         int                     len;
725         int                     field_len;
726         regex_match_func        match;
727 };
728
729 struct filter_pred {
730         filter_pred_fn_t        fn;
731         u64                     val;
732         struct regex            regex;
733         char                    *field_name;
734         int                     offset;
735         int                     not;
736         int                     op;
737         int                     pop_n;
738 };
739
740 extern enum regex_type
741 filter_parse_regex(char *buff, int len, char **search, int *not);
742 extern void print_event_filter(struct ftrace_event_call *call,
743                                struct trace_seq *s);
744 extern int apply_event_filter(struct ftrace_event_call *call,
745                               char *filter_string);
746 extern int apply_subsystem_event_filter(struct event_subsystem *system,
747                                         char *filter_string);
748 extern void print_subsystem_event_filter(struct event_subsystem *system,
749                                          struct trace_seq *s);
750 extern int filter_assign_type(const char *type);
751
752 static inline int
753 filter_check_discard(struct ftrace_event_call *call, void *rec,
754                      struct ring_buffer *buffer,
755                      struct ring_buffer_event *event)
756 {
757         if (unlikely(call->filter_active) &&
758             !filter_match_preds(call->filter, rec)) {
759                 ring_buffer_discard_commit(buffer, event);
760                 return 1;
761         }
762
763         return 0;
764 }
765
766 extern struct mutex event_mutex;
767 extern struct list_head ftrace_events;
768
769 extern const char *__start___trace_bprintk_fmt[];
770 extern const char *__stop___trace_bprintk_fmt[];
771
772 #undef FTRACE_ENTRY
773 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)             \
774         extern struct ftrace_event_call event_##call;
775 #undef FTRACE_ENTRY_DUP
776 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)         \
777         FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
778 #include "trace_entries.h"
779
780 #endif /* _LINUX_KERNEL_TRACE_H */