tracing: remove dead code
[linux-2.6.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/ftrace.h>
11 #include <trace/boot.h>
12 #include <linux/kmemtrace.h>
13 #include <trace/power.h>
14
15 #include <linux/trace_seq.h>
16 #include <linux/ftrace_event.h>
17
18 enum trace_type {
19         __TRACE_FIRST_TYPE = 0,
20
21         TRACE_FN,
22         TRACE_CTX,
23         TRACE_WAKE,
24         TRACE_STACK,
25         TRACE_PRINT,
26         TRACE_BPRINT,
27         TRACE_SPECIAL,
28         TRACE_MMIO_RW,
29         TRACE_MMIO_MAP,
30         TRACE_BRANCH,
31         TRACE_BOOT_CALL,
32         TRACE_BOOT_RET,
33         TRACE_GRAPH_RET,
34         TRACE_GRAPH_ENT,
35         TRACE_USER_STACK,
36         TRACE_HW_BRANCHES,
37         TRACE_KMEM_ALLOC,
38         TRACE_KMEM_FREE,
39         TRACE_POWER,
40         TRACE_BLK,
41
42         __TRACE_LAST_TYPE,
43 };
44
45 /*
46  * Function trace entry - function address and parent function addres:
47  */
48 struct ftrace_entry {
49         struct trace_entry      ent;
50         unsigned long           ip;
51         unsigned long           parent_ip;
52 };
53
54 /* Function call entry */
55 struct ftrace_graph_ent_entry {
56         struct trace_entry              ent;
57         struct ftrace_graph_ent         graph_ent;
58 };
59
60 /* Function return entry */
61 struct ftrace_graph_ret_entry {
62         struct trace_entry              ent;
63         struct ftrace_graph_ret         ret;
64 };
65 extern struct tracer boot_tracer;
66
67 /*
68  * Context switch trace entry - which task (and prio) we switched from/to:
69  */
70 struct ctx_switch_entry {
71         struct trace_entry      ent;
72         unsigned int            prev_pid;
73         unsigned char           prev_prio;
74         unsigned char           prev_state;
75         unsigned int            next_pid;
76         unsigned char           next_prio;
77         unsigned char           next_state;
78         unsigned int            next_cpu;
79 };
80
81 /*
82  * Special (free-form) trace entry:
83  */
84 struct special_entry {
85         struct trace_entry      ent;
86         unsigned long           arg1;
87         unsigned long           arg2;
88         unsigned long           arg3;
89 };
90
91 /*
92  * Stack-trace entry:
93  */
94
95 #define FTRACE_STACK_ENTRIES    8
96
97 struct stack_entry {
98         struct trace_entry      ent;
99         unsigned long           caller[FTRACE_STACK_ENTRIES];
100 };
101
102 struct userstack_entry {
103         struct trace_entry      ent;
104         unsigned long           caller[FTRACE_STACK_ENTRIES];
105 };
106
107 /*
108  * trace_printk entry:
109  */
110 struct bprint_entry {
111         struct trace_entry      ent;
112         unsigned long           ip;
113         const char              *fmt;
114         u32                     buf[];
115 };
116
117 struct print_entry {
118         struct trace_entry      ent;
119         unsigned long           ip;
120         char                    buf[];
121 };
122
123 struct trace_mmiotrace_rw {
124         struct trace_entry      ent;
125         struct mmiotrace_rw     rw;
126 };
127
128 struct trace_mmiotrace_map {
129         struct trace_entry      ent;
130         struct mmiotrace_map    map;
131 };
132
133 struct trace_boot_call {
134         struct trace_entry      ent;
135         struct boot_trace_call boot_call;
136 };
137
138 struct trace_boot_ret {
139         struct trace_entry      ent;
140         struct boot_trace_ret boot_ret;
141 };
142
143 #define TRACE_FUNC_SIZE 30
144 #define TRACE_FILE_SIZE 20
145 struct trace_branch {
146         struct trace_entry      ent;
147         unsigned                line;
148         char                    func[TRACE_FUNC_SIZE+1];
149         char                    file[TRACE_FILE_SIZE+1];
150         char                    correct;
151 };
152
153 struct hw_branch_entry {
154         struct trace_entry      ent;
155         u64                     from;
156         u64                     to;
157 };
158
159 struct trace_power {
160         struct trace_entry      ent;
161         struct power_trace      state_data;
162 };
163
164 enum kmemtrace_type_id {
165         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
166         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
167         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
168 };
169
170 struct kmemtrace_alloc_entry {
171         struct trace_entry      ent;
172         enum kmemtrace_type_id type_id;
173         unsigned long call_site;
174         const void *ptr;
175         size_t bytes_req;
176         size_t bytes_alloc;
177         gfp_t gfp_flags;
178         int node;
179 };
180
181 struct kmemtrace_free_entry {
182         struct trace_entry      ent;
183         enum kmemtrace_type_id type_id;
184         unsigned long call_site;
185         const void *ptr;
186 };
187
188 struct syscall_trace_enter {
189         struct trace_entry      ent;
190         int                     nr;
191         unsigned long           args[];
192 };
193
194 struct syscall_trace_exit {
195         struct trace_entry      ent;
196         int                     nr;
197         unsigned long           ret;
198 };
199
200
201 /*
202  * trace_flag_type is an enumeration that holds different
203  * states when a trace occurs. These are:
204  *  IRQS_OFF            - interrupts were disabled
205  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
206  *  NEED_RESCED         - reschedule is requested
207  *  HARDIRQ             - inside an interrupt handler
208  *  SOFTIRQ             - inside a softirq handler
209  */
210 enum trace_flag_type {
211         TRACE_FLAG_IRQS_OFF             = 0x01,
212         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
213         TRACE_FLAG_NEED_RESCHED         = 0x04,
214         TRACE_FLAG_HARDIRQ              = 0x08,
215         TRACE_FLAG_SOFTIRQ              = 0x10,
216 };
217
218 #define TRACE_BUF_SIZE          1024
219
220 /*
221  * The CPU trace array - it consists of thousands of trace entries
222  * plus some other descriptor data: (for example which task started
223  * the trace, etc.)
224  */
225 struct trace_array_cpu {
226         atomic_t                disabled;
227         void                    *buffer_page;   /* ring buffer spare */
228
229         unsigned long           saved_latency;
230         unsigned long           critical_start;
231         unsigned long           critical_end;
232         unsigned long           critical_sequence;
233         unsigned long           nice;
234         unsigned long           policy;
235         unsigned long           rt_priority;
236         unsigned long           skipped_entries;
237         cycle_t                 preempt_timestamp;
238         pid_t                   pid;
239         uid_t                   uid;
240         char                    comm[TASK_COMM_LEN];
241 };
242
243 /*
244  * The trace array - an array of per-CPU trace arrays. This is the
245  * highest level data structure that individual tracers deal with.
246  * They have on/off state as well:
247  */
248 struct trace_array {
249         struct ring_buffer      *buffer;
250         unsigned long           entries;
251         int                     cpu;
252         cycle_t                 time_start;
253         struct task_struct      *waiter;
254         struct trace_array_cpu  *data[NR_CPUS];
255 };
256
257 #define FTRACE_CMP_TYPE(var, type) \
258         __builtin_types_compatible_p(typeof(var), type *)
259
260 #undef IF_ASSIGN
261 #define IF_ASSIGN(var, entry, etype, id)                \
262         if (FTRACE_CMP_TYPE(var, etype)) {              \
263                 var = (typeof(var))(entry);             \
264                 WARN_ON(id && (entry)->type != id);     \
265                 break;                                  \
266         }
267
268 /* Will cause compile errors if type is not found. */
269 extern void __ftrace_bad_type(void);
270
271 /*
272  * The trace_assign_type is a verifier that the entry type is
273  * the same as the type being assigned. To add new types simply
274  * add a line with the following format:
275  *
276  * IF_ASSIGN(var, ent, type, id);
277  *
278  *  Where "type" is the trace type that includes the trace_entry
279  *  as the "ent" item. And "id" is the trace identifier that is
280  *  used in the trace_type enum.
281  *
282  *  If the type can have more than one id, then use zero.
283  */
284 #define trace_assign_type(var, ent)                                     \
285         do {                                                            \
286                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
287                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
288                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
289                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
290                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
291                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
292                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
293                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
294                           TRACE_MMIO_RW);                               \
295                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
296                           TRACE_MMIO_MAP);                              \
297                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
298                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
299                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
300                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
301                           TRACE_GRAPH_ENT);             \
302                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
303                           TRACE_GRAPH_RET);             \
304                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
305                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
306                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
307                           TRACE_KMEM_ALLOC);    \
308                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
309                           TRACE_KMEM_FREE);     \
310                 __ftrace_bad_type();                                    \
311         } while (0)
312
313 /*
314  * An option specific to a tracer. This is a boolean value.
315  * The bit is the bit index that sets its value on the
316  * flags value in struct tracer_flags.
317  */
318 struct tracer_opt {
319         const char      *name; /* Will appear on the trace_options file */
320         u32             bit; /* Mask assigned in val field in tracer_flags */
321 };
322
323 /*
324  * The set of specific options for a tracer. Your tracer
325  * have to set the initial value of the flags val.
326  */
327 struct tracer_flags {
328         u32                     val;
329         struct tracer_opt       *opts;
330 };
331
332 /* Makes more easy to define a tracer opt */
333 #define TRACER_OPT(s, b)        .name = #s, .bit = b
334
335
336 /**
337  * struct tracer - a specific tracer and its callbacks to interact with debugfs
338  * @name: the name chosen to select it on the available_tracers file
339  * @init: called when one switches to this tracer (echo name > current_tracer)
340  * @reset: called when one switches to another tracer
341  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
342  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
343  * @open: called when the trace file is opened
344  * @pipe_open: called when the trace_pipe file is opened
345  * @wait_pipe: override how the user waits for traces on trace_pipe
346  * @close: called when the trace file is released
347  * @read: override the default read callback on trace_pipe
348  * @splice_read: override the default splice_read callback on trace_pipe
349  * @selftest: selftest to run on boot (see trace_selftest.c)
350  * @print_headers: override the first lines that describe your columns
351  * @print_line: callback that prints a trace
352  * @set_flag: signals one of your private flags changed (trace_options file)
353  * @flags: your private flags
354  */
355 struct tracer {
356         const char              *name;
357         int                     (*init)(struct trace_array *tr);
358         void                    (*reset)(struct trace_array *tr);
359         void                    (*start)(struct trace_array *tr);
360         void                    (*stop)(struct trace_array *tr);
361         void                    (*open)(struct trace_iterator *iter);
362         void                    (*pipe_open)(struct trace_iterator *iter);
363         void                    (*wait_pipe)(struct trace_iterator *iter);
364         void                    (*close)(struct trace_iterator *iter);
365         ssize_t                 (*read)(struct trace_iterator *iter,
366                                         struct file *filp, char __user *ubuf,
367                                         size_t cnt, loff_t *ppos);
368         ssize_t                 (*splice_read)(struct trace_iterator *iter,
369                                                struct file *filp,
370                                                loff_t *ppos,
371                                                struct pipe_inode_info *pipe,
372                                                size_t len,
373                                                unsigned int flags);
374 #ifdef CONFIG_FTRACE_STARTUP_TEST
375         int                     (*selftest)(struct tracer *trace,
376                                             struct trace_array *tr);
377 #endif
378         void                    (*print_header)(struct seq_file *m);
379         enum print_line_t       (*print_line)(struct trace_iterator *iter);
380         /* If you handled the flag setting, return 0 */
381         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
382         struct tracer           *next;
383         int                     print_max;
384         struct tracer_flags     *flags;
385         struct tracer_stat      *stats;
386 };
387
388
389 #define TRACE_PIPE_ALL_CPU      -1
390
391 int tracer_init(struct tracer *t, struct trace_array *tr);
392 int tracing_is_enabled(void);
393 void trace_wake_up(void);
394 void tracing_reset(struct trace_array *tr, int cpu);
395 void tracing_reset_online_cpus(struct trace_array *tr);
396 void tracing_reset_current(int cpu);
397 void tracing_reset_current_online_cpus(void);
398 int tracing_open_generic(struct inode *inode, struct file *filp);
399 struct dentry *trace_create_file(const char *name,
400                                  mode_t mode,
401                                  struct dentry *parent,
402                                  void *data,
403                                  const struct file_operations *fops);
404
405 struct dentry *tracing_init_dentry(void);
406 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
407
408 struct ring_buffer_event;
409
410 struct ring_buffer_event *
411 trace_buffer_lock_reserve(struct ring_buffer *buffer,
412                           int type,
413                           unsigned long len,
414                           unsigned long flags,
415                           int pc);
416 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
417                                 struct ring_buffer_event *event,
418                                 unsigned long flags, int pc);
419
420 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
421                                                 struct trace_array_cpu *data);
422
423 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
424                                           int *ent_cpu, u64 *ent_ts);
425
426 void default_wait_pipe(struct trace_iterator *iter);
427 void poll_wait_pipe(struct trace_iterator *iter);
428
429 void ftrace(struct trace_array *tr,
430                             struct trace_array_cpu *data,
431                             unsigned long ip,
432                             unsigned long parent_ip,
433                             unsigned long flags, int pc);
434 void tracing_sched_switch_trace(struct trace_array *tr,
435                                 struct task_struct *prev,
436                                 struct task_struct *next,
437                                 unsigned long flags, int pc);
438
439 void tracing_sched_wakeup_trace(struct trace_array *tr,
440                                 struct task_struct *wakee,
441                                 struct task_struct *cur,
442                                 unsigned long flags, int pc);
443 void trace_special(struct trace_array *tr,
444                    struct trace_array_cpu *data,
445                    unsigned long arg1,
446                    unsigned long arg2,
447                    unsigned long arg3, int pc);
448 void trace_function(struct trace_array *tr,
449                     unsigned long ip,
450                     unsigned long parent_ip,
451                     unsigned long flags, int pc);
452
453 void trace_graph_return(struct ftrace_graph_ret *trace);
454 int trace_graph_entry(struct ftrace_graph_ent *trace);
455 void set_graph_array(struct trace_array *tr);
456
457 void tracing_start_cmdline_record(void);
458 void tracing_stop_cmdline_record(void);
459 void tracing_sched_switch_assign_trace(struct trace_array *tr);
460 void tracing_stop_sched_switch_record(void);
461 void tracing_start_sched_switch_record(void);
462 int register_tracer(struct tracer *type);
463 void unregister_tracer(struct tracer *type);
464
465 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
466
467 #ifdef CONFIG_TRACER_MAX_TRACE
468 extern unsigned long tracing_max_latency;
469 extern unsigned long tracing_thresh;
470
471 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
472 void update_max_tr_single(struct trace_array *tr,
473                           struct task_struct *tsk, int cpu);
474 #endif /* CONFIG_TRACER_MAX_TRACE */
475
476 #ifdef CONFIG_STACKTRACE
477 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
478                         int skip, int pc);
479
480 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
481                             int pc);
482
483 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
484                    int pc);
485 #else
486 static inline void ftrace_trace_stack(struct trace_array *tr,
487                                       unsigned long flags, int skip, int pc)
488 {
489 }
490
491 static inline void ftrace_trace_userstack(struct trace_array *tr,
492                                           unsigned long flags, int pc)
493 {
494 }
495
496 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
497                                  int skip, int pc)
498 {
499 }
500 #endif /* CONFIG_STACKTRACE */
501
502 extern cycle_t ftrace_now(int cpu);
503
504 extern void trace_find_cmdline(int pid, char comm[]);
505
506 #ifdef CONFIG_DYNAMIC_FTRACE
507 extern unsigned long ftrace_update_tot_cnt;
508 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
509 extern int DYN_FTRACE_TEST_NAME(void);
510 #endif
511
512 extern int ring_buffer_expanded;
513 extern bool tracing_selftest_disabled;
514 DECLARE_PER_CPU(local_t, ftrace_cpu_disabled);
515
516 #ifdef CONFIG_FTRACE_STARTUP_TEST
517 extern int trace_selftest_startup_function(struct tracer *trace,
518                                            struct trace_array *tr);
519 extern int trace_selftest_startup_function_graph(struct tracer *trace,
520                                                  struct trace_array *tr);
521 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
522                                           struct trace_array *tr);
523 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
524                                              struct trace_array *tr);
525 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
526                                                  struct trace_array *tr);
527 extern int trace_selftest_startup_wakeup(struct tracer *trace,
528                                          struct trace_array *tr);
529 extern int trace_selftest_startup_nop(struct tracer *trace,
530                                          struct trace_array *tr);
531 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
532                                                struct trace_array *tr);
533 extern int trace_selftest_startup_sysprof(struct tracer *trace,
534                                                struct trace_array *tr);
535 extern int trace_selftest_startup_branch(struct tracer *trace,
536                                          struct trace_array *tr);
537 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
538                                               struct trace_array *tr);
539 #endif /* CONFIG_FTRACE_STARTUP_TEST */
540
541 extern void *head_page(struct trace_array_cpu *data);
542 extern unsigned long long ns2usecs(cycle_t nsec);
543 extern int
544 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
545 extern int
546 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
547 extern int
548 trace_array_vprintk(struct trace_array *tr,
549                     unsigned long ip, const char *fmt, va_list args);
550 int trace_array_printk(struct trace_array *tr,
551                        unsigned long ip, const char *fmt, ...);
552
553 extern unsigned long trace_flags;
554
555 extern int trace_clock_id;
556
557 /* Standard output formatting function used for function return traces */
558 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
559 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
560 extern enum print_line_t
561 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
562
563 #ifdef CONFIG_DYNAMIC_FTRACE
564 /* TODO: make this variable */
565 #define FTRACE_GRAPH_MAX_FUNCS          32
566 extern int ftrace_graph_count;
567 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
568
569 static inline int ftrace_graph_addr(unsigned long addr)
570 {
571         int i;
572
573         if (!ftrace_graph_count || test_tsk_trace_graph(current))
574                 return 1;
575
576         for (i = 0; i < ftrace_graph_count; i++) {
577                 if (addr == ftrace_graph_funcs[i])
578                         return 1;
579         }
580
581         return 0;
582 }
583 #else
584 static inline int ftrace_trace_addr(unsigned long addr)
585 {
586         return 1;
587 }
588 static inline int ftrace_graph_addr(unsigned long addr)
589 {
590         return 1;
591 }
592 #endif /* CONFIG_DYNAMIC_FTRACE */
593 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
594 static inline enum print_line_t
595 print_graph_function(struct trace_iterator *iter)
596 {
597         return TRACE_TYPE_UNHANDLED;
598 }
599 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
600
601 extern struct pid *ftrace_pid_trace;
602
603 #ifdef CONFIG_FUNCTION_TRACER
604 static inline int ftrace_trace_task(struct task_struct *task)
605 {
606         if (!ftrace_pid_trace)
607                 return 1;
608
609         return test_tsk_trace_trace(task);
610 }
611 #else
612 static inline int ftrace_trace_task(struct task_struct *task)
613 {
614         return 1;
615 }
616 #endif
617
618 /*
619  * trace_iterator_flags is an enumeration that defines bit
620  * positions into trace_flags that controls the output.
621  *
622  * NOTE: These bits must match the trace_options array in
623  *       trace.c.
624  */
625 enum trace_iterator_flags {
626         TRACE_ITER_PRINT_PARENT         = 0x01,
627         TRACE_ITER_SYM_OFFSET           = 0x02,
628         TRACE_ITER_SYM_ADDR             = 0x04,
629         TRACE_ITER_VERBOSE              = 0x08,
630         TRACE_ITER_RAW                  = 0x10,
631         TRACE_ITER_HEX                  = 0x20,
632         TRACE_ITER_BIN                  = 0x40,
633         TRACE_ITER_BLOCK                = 0x80,
634         TRACE_ITER_STACKTRACE           = 0x100,
635         TRACE_ITER_SCHED_TREE           = 0x200,
636         TRACE_ITER_PRINTK               = 0x400,
637         TRACE_ITER_PREEMPTONLY          = 0x800,
638         TRACE_ITER_BRANCH               = 0x1000,
639         TRACE_ITER_ANNOTATE             = 0x2000,
640         TRACE_ITER_USERSTACKTRACE       = 0x4000,
641         TRACE_ITER_SYM_USEROBJ          = 0x8000,
642         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
643         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
644         TRACE_ITER_LATENCY_FMT          = 0x40000,
645         TRACE_ITER_SLEEP_TIME           = 0x80000,
646         TRACE_ITER_GRAPH_TIME           = 0x100000,
647 };
648
649 /*
650  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
651  * control the output of kernel symbols.
652  */
653 #define TRACE_ITER_SYM_MASK \
654         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
655
656 extern struct tracer nop_trace;
657
658 /**
659  * ftrace_preempt_disable - disable preemption scheduler safe
660  *
661  * When tracing can happen inside the scheduler, there exists
662  * cases that the tracing might happen before the need_resched
663  * flag is checked. If this happens and the tracer calls
664  * preempt_enable (after a disable), a schedule might take place
665  * causing an infinite recursion.
666  *
667  * To prevent this, we read the need_resched flag before
668  * disabling preemption. When we want to enable preemption we
669  * check the flag, if it is set, then we call preempt_enable_no_resched.
670  * Otherwise, we call preempt_enable.
671  *
672  * The rational for doing the above is that if need_resched is set
673  * and we have yet to reschedule, we are either in an atomic location
674  * (where we do not need to check for scheduling) or we are inside
675  * the scheduler and do not want to resched.
676  */
677 static inline int ftrace_preempt_disable(void)
678 {
679         int resched;
680
681         resched = need_resched();
682         preempt_disable_notrace();
683
684         return resched;
685 }
686
687 /**
688  * ftrace_preempt_enable - enable preemption scheduler safe
689  * @resched: the return value from ftrace_preempt_disable
690  *
691  * This is a scheduler safe way to enable preemption and not miss
692  * any preemption checks. The disabled saved the state of preemption.
693  * If resched is set, then we are either inside an atomic or
694  * are inside the scheduler (we would have already scheduled
695  * otherwise). In this case, we do not want to call normal
696  * preempt_enable, but preempt_enable_no_resched instead.
697  */
698 static inline void ftrace_preempt_enable(int resched)
699 {
700         if (resched)
701                 preempt_enable_no_resched_notrace();
702         else
703                 preempt_enable_notrace();
704 }
705
706 #ifdef CONFIG_BRANCH_TRACER
707 extern int enable_branch_tracing(struct trace_array *tr);
708 extern void disable_branch_tracing(void);
709 static inline int trace_branch_enable(struct trace_array *tr)
710 {
711         if (trace_flags & TRACE_ITER_BRANCH)
712                 return enable_branch_tracing(tr);
713         return 0;
714 }
715 static inline void trace_branch_disable(void)
716 {
717         /* due to races, always disable */
718         disable_branch_tracing();
719 }
720 #else
721 static inline int trace_branch_enable(struct trace_array *tr)
722 {
723         return 0;
724 }
725 static inline void trace_branch_disable(void)
726 {
727 }
728 #endif /* CONFIG_BRANCH_TRACER */
729
730 /* set ring buffers to default size if not already done so */
731 int tracing_update_buffers(void);
732
733 /* trace event type bit fields, not numeric */
734 enum {
735         TRACE_EVENT_TYPE_PRINTF         = 1,
736         TRACE_EVENT_TYPE_RAW            = 2,
737 };
738
739 struct ftrace_event_field {
740         struct list_head        link;
741         char                    *name;
742         char                    *type;
743         int                     filter_type;
744         int                     offset;
745         int                     size;
746         int                     is_signed;
747 };
748
749 struct event_filter {
750         int                     n_preds;
751         struct filter_pred      **preds;
752         char                    *filter_string;
753         bool                    no_reset;
754 };
755
756 struct event_subsystem {
757         struct list_head        list;
758         const char              *name;
759         struct dentry           *entry;
760         struct event_filter     *filter;
761         int                     nr_events;
762 };
763
764 struct filter_pred;
765
766 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
767                                  int val1, int val2);
768
769 struct filter_pred {
770         filter_pred_fn_t fn;
771         u64 val;
772         char str_val[MAX_FILTER_STR_VAL];
773         int str_len;
774         char *field_name;
775         int offset;
776         int not;
777         int op;
778         int pop_n;
779 };
780
781 extern void print_event_filter(struct ftrace_event_call *call,
782                                struct trace_seq *s);
783 extern int apply_event_filter(struct ftrace_event_call *call,
784                               char *filter_string);
785 extern int apply_subsystem_event_filter(struct event_subsystem *system,
786                                         char *filter_string);
787 extern void print_subsystem_event_filter(struct event_subsystem *system,
788                                          struct trace_seq *s);
789 extern int filter_assign_type(const char *type);
790
791 static inline int
792 filter_check_discard(struct ftrace_event_call *call, void *rec,
793                      struct ring_buffer *buffer,
794                      struct ring_buffer_event *event)
795 {
796         if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) {
797                 ring_buffer_discard_commit(buffer, event);
798                 return 1;
799         }
800
801         return 0;
802 }
803
804 #define DEFINE_COMPARISON_PRED(type)                                    \
805 static int filter_pred_##type(struct filter_pred *pred, void *event,    \
806                               int val1, int val2)                       \
807 {                                                                       \
808         type *addr = (type *)(event + pred->offset);                    \
809         type val = (type)pred->val;                                     \
810         int match = 0;                                                  \
811                                                                         \
812         switch (pred->op) {                                             \
813         case OP_LT:                                                     \
814                 match = (*addr < val);                                  \
815                 break;                                                  \
816         case OP_LE:                                                     \
817                 match = (*addr <= val);                                 \
818                 break;                                                  \
819         case OP_GT:                                                     \
820                 match = (*addr > val);                                  \
821                 break;                                                  \
822         case OP_GE:                                                     \
823                 match = (*addr >= val);                                 \
824                 break;                                                  \
825         default:                                                        \
826                 break;                                                  \
827         }                                                               \
828                                                                         \
829         return match;                                                   \
830 }
831
832 #define DEFINE_EQUALITY_PRED(size)                                      \
833 static int filter_pred_##size(struct filter_pred *pred, void *event,    \
834                               int val1, int val2)                       \
835 {                                                                       \
836         u##size *addr = (u##size *)(event + pred->offset);              \
837         u##size val = (u##size)pred->val;                               \
838         int match;                                                      \
839                                                                         \
840         match = (val == *addr) ^ pred->not;                             \
841                                                                         \
842         return match;                                                   \
843 }
844
845 extern struct mutex event_mutex;
846 extern struct list_head ftrace_events;
847
848 extern const char *__start___trace_bprintk_fmt[];
849 extern const char *__stop___trace_bprintk_fmt[];
850
851 #undef TRACE_EVENT_FORMAT
852 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
853         extern struct ftrace_event_call event_##call;
854 #undef TRACE_EVENT_FORMAT_NOFILTER
855 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt)
856 #include "trace_event_types.h"
857
858 #endif /* _LINUX_KERNEL_TRACE_H */