Merge branches 'tracing/ftrace', 'tracing/syscalls' and 'linus' into tracing/core
[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 <trace/kmemtrace.h>
13 #include <trace/power.h>
14
15 enum trace_type {
16         __TRACE_FIRST_TYPE = 0,
17
18         TRACE_FN,
19         TRACE_CTX,
20         TRACE_WAKE,
21         TRACE_STACK,
22         TRACE_PRINT,
23         TRACE_BPRINT,
24         TRACE_SPECIAL,
25         TRACE_MMIO_RW,
26         TRACE_MMIO_MAP,
27         TRACE_BRANCH,
28         TRACE_BOOT_CALL,
29         TRACE_BOOT_RET,
30         TRACE_GRAPH_RET,
31         TRACE_GRAPH_ENT,
32         TRACE_USER_STACK,
33         TRACE_HW_BRANCHES,
34         TRACE_SYSCALL_ENTER,
35         TRACE_SYSCALL_EXIT,
36         TRACE_KMEM_ALLOC,
37         TRACE_KMEM_FREE,
38         TRACE_POWER,
39         TRACE_BLK,
40
41         __TRACE_LAST_TYPE,
42 };
43
44 /*
45  * The trace entry - the most basic unit of tracing. This is what
46  * is printed in the end as a single line in the trace output, such as:
47  *
48  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
49  */
50 struct trace_entry {
51         unsigned char           type;
52         unsigned char           flags;
53         unsigned char           preempt_count;
54         int                     pid;
55         int                     tgid;
56 };
57
58 /*
59  * Function trace entry - function address and parent function addres:
60  */
61 struct ftrace_entry {
62         struct trace_entry      ent;
63         unsigned long           ip;
64         unsigned long           parent_ip;
65 };
66
67 /* Function call entry */
68 struct ftrace_graph_ent_entry {
69         struct trace_entry              ent;
70         struct ftrace_graph_ent         graph_ent;
71 };
72
73 /* Function return entry */
74 struct ftrace_graph_ret_entry {
75         struct trace_entry              ent;
76         struct ftrace_graph_ret         ret;
77 };
78 extern struct tracer boot_tracer;
79
80 /*
81  * Context switch trace entry - which task (and prio) we switched from/to:
82  */
83 struct ctx_switch_entry {
84         struct trace_entry      ent;
85         unsigned int            prev_pid;
86         unsigned char           prev_prio;
87         unsigned char           prev_state;
88         unsigned int            next_pid;
89         unsigned char           next_prio;
90         unsigned char           next_state;
91         unsigned int            next_cpu;
92 };
93
94 /*
95  * Special (free-form) trace entry:
96  */
97 struct special_entry {
98         struct trace_entry      ent;
99         unsigned long           arg1;
100         unsigned long           arg2;
101         unsigned long           arg3;
102 };
103
104 /*
105  * Stack-trace entry:
106  */
107
108 #define FTRACE_STACK_ENTRIES    8
109
110 struct stack_entry {
111         struct trace_entry      ent;
112         unsigned long           caller[FTRACE_STACK_ENTRIES];
113 };
114
115 struct userstack_entry {
116         struct trace_entry      ent;
117         unsigned long           caller[FTRACE_STACK_ENTRIES];
118 };
119
120 /*
121  * trace_printk entry:
122  */
123 struct bprint_entry {
124         struct trace_entry      ent;
125         unsigned long           ip;
126         int                     depth;
127         const char              *fmt;
128         u32                     buf[];
129 };
130
131 struct print_entry {
132         struct trace_entry      ent;
133         unsigned long           ip;
134         int                     depth;
135         char                    buf[];
136 };
137
138 #define TRACE_OLD_SIZE          88
139
140 struct trace_field_cont {
141         unsigned char           type;
142         /* Temporary till we get rid of this completely */
143         char                    buf[TRACE_OLD_SIZE - 1];
144 };
145
146 struct trace_mmiotrace_rw {
147         struct trace_entry      ent;
148         struct mmiotrace_rw     rw;
149 };
150
151 struct trace_mmiotrace_map {
152         struct trace_entry      ent;
153         struct mmiotrace_map    map;
154 };
155
156 struct trace_boot_call {
157         struct trace_entry      ent;
158         struct boot_trace_call boot_call;
159 };
160
161 struct trace_boot_ret {
162         struct trace_entry      ent;
163         struct boot_trace_ret boot_ret;
164 };
165
166 #define TRACE_FUNC_SIZE 30
167 #define TRACE_FILE_SIZE 20
168 struct trace_branch {
169         struct trace_entry      ent;
170         unsigned                line;
171         char                    func[TRACE_FUNC_SIZE+1];
172         char                    file[TRACE_FILE_SIZE+1];
173         char                    correct;
174 };
175
176 struct hw_branch_entry {
177         struct trace_entry      ent;
178         u64                     from;
179         u64                     to;
180 };
181
182 struct trace_power {
183         struct trace_entry      ent;
184         struct power_trace      state_data;
185 };
186
187 struct kmemtrace_alloc_entry {
188         struct trace_entry      ent;
189         enum kmemtrace_type_id type_id;
190         unsigned long call_site;
191         const void *ptr;
192         size_t bytes_req;
193         size_t bytes_alloc;
194         gfp_t gfp_flags;
195         int node;
196 };
197
198 struct kmemtrace_free_entry {
199         struct trace_entry      ent;
200         enum kmemtrace_type_id type_id;
201         unsigned long call_site;
202         const void *ptr;
203 };
204
205 struct syscall_trace_enter {
206         struct trace_entry      ent;
207         int                     nr;
208         unsigned long           args[];
209 };
210
211 struct syscall_trace_exit {
212         struct trace_entry      ent;
213         int                     nr;
214         unsigned long           ret;
215 };
216
217
218 /*
219  * trace_flag_type is an enumeration that holds different
220  * states when a trace occurs. These are:
221  *  IRQS_OFF            - interrupts were disabled
222  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
223  *  NEED_RESCED         - reschedule is requested
224  *  HARDIRQ             - inside an interrupt handler
225  *  SOFTIRQ             - inside a softirq handler
226  */
227 enum trace_flag_type {
228         TRACE_FLAG_IRQS_OFF             = 0x01,
229         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
230         TRACE_FLAG_NEED_RESCHED         = 0x04,
231         TRACE_FLAG_HARDIRQ              = 0x08,
232         TRACE_FLAG_SOFTIRQ              = 0x10,
233 };
234
235 #define TRACE_BUF_SIZE          1024
236
237 /*
238  * The CPU trace array - it consists of thousands of trace entries
239  * plus some other descriptor data: (for example which task started
240  * the trace, etc.)
241  */
242 struct trace_array_cpu {
243         atomic_t                disabled;
244         void                    *buffer_page;   /* ring buffer spare */
245
246         /* these fields get copied into max-trace: */
247         unsigned long           trace_idx;
248         unsigned long           overrun;
249         unsigned long           saved_latency;
250         unsigned long           critical_start;
251         unsigned long           critical_end;
252         unsigned long           critical_sequence;
253         unsigned long           nice;
254         unsigned long           policy;
255         unsigned long           rt_priority;
256         cycle_t                 preempt_timestamp;
257         pid_t                   pid;
258         uid_t                   uid;
259         char                    comm[TASK_COMM_LEN];
260 };
261
262 struct trace_iterator;
263
264 /*
265  * The trace array - an array of per-CPU trace arrays. This is the
266  * highest level data structure that individual tracers deal with.
267  * They have on/off state as well:
268  */
269 struct trace_array {
270         struct ring_buffer      *buffer;
271         unsigned long           entries;
272         int                     cpu;
273         cycle_t                 time_start;
274         struct task_struct      *waiter;
275         struct trace_array_cpu  *data[NR_CPUS];
276 };
277
278 #define FTRACE_CMP_TYPE(var, type) \
279         __builtin_types_compatible_p(typeof(var), type *)
280
281 #undef IF_ASSIGN
282 #define IF_ASSIGN(var, entry, etype, id)                \
283         if (FTRACE_CMP_TYPE(var, etype)) {              \
284                 var = (typeof(var))(entry);             \
285                 WARN_ON(id && (entry)->type != id);     \
286                 break;                                  \
287         }
288
289 /* Will cause compile errors if type is not found. */
290 extern void __ftrace_bad_type(void);
291
292 /*
293  * The trace_assign_type is a verifier that the entry type is
294  * the same as the type being assigned. To add new types simply
295  * add a line with the following format:
296  *
297  * IF_ASSIGN(var, ent, type, id);
298  *
299  *  Where "type" is the trace type that includes the trace_entry
300  *  as the "ent" item. And "id" is the trace identifier that is
301  *  used in the trace_type enum.
302  *
303  *  If the type can have more than one id, then use zero.
304  */
305 #define trace_assign_type(var, ent)                                     \
306         do {                                                            \
307                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
308                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
309                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
310                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
311                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
312                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
313                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
314                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
315                           TRACE_MMIO_RW);                               \
316                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
317                           TRACE_MMIO_MAP);                              \
318                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
319                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
320                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
321                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
322                           TRACE_GRAPH_ENT);             \
323                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
324                           TRACE_GRAPH_RET);             \
325                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
326                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
327                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
328                           TRACE_KMEM_ALLOC);    \
329                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
330                           TRACE_KMEM_FREE);     \
331                 IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
332                           TRACE_SYSCALL_ENTER);                         \
333                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
334                           TRACE_SYSCALL_EXIT);                          \
335                 __ftrace_bad_type();                                    \
336         } while (0)
337
338 /* Return values for print_line callback */
339 enum print_line_t {
340         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
341         TRACE_TYPE_HANDLED      = 1,
342         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
343         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
344 };
345
346
347 /*
348  * An option specific to a tracer. This is a boolean value.
349  * The bit is the bit index that sets its value on the
350  * flags value in struct tracer_flags.
351  */
352 struct tracer_opt {
353         const char      *name; /* Will appear on the trace_options file */
354         u32             bit; /* Mask assigned in val field in tracer_flags */
355 };
356
357 /*
358  * The set of specific options for a tracer. Your tracer
359  * have to set the initial value of the flags val.
360  */
361 struct tracer_flags {
362         u32                     val;
363         struct tracer_opt       *opts;
364 };
365
366 /* Makes more easy to define a tracer opt */
367 #define TRACER_OPT(s, b)        .name = #s, .bit = b
368
369
370 /**
371  * struct tracer - a specific tracer and its callbacks to interact with debugfs
372  * @name: the name chosen to select it on the available_tracers file
373  * @init: called when one switches to this tracer (echo name > current_tracer)
374  * @reset: called when one switches to another tracer
375  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
376  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
377  * @open: called when the trace file is opened
378  * @pipe_open: called when the trace_pipe file is opened
379  * @wait_pipe: override how the user waits for traces on trace_pipe
380  * @close: called when the trace file is released
381  * @read: override the default read callback on trace_pipe
382  * @splice_read: override the default splice_read callback on trace_pipe
383  * @selftest: selftest to run on boot (see trace_selftest.c)
384  * @print_headers: override the first lines that describe your columns
385  * @print_line: callback that prints a trace
386  * @set_flag: signals one of your private flags changed (trace_options file)
387  * @flags: your private flags
388  */
389 struct tracer {
390         const char              *name;
391         int                     (*init)(struct trace_array *tr);
392         void                    (*reset)(struct trace_array *tr);
393         void                    (*start)(struct trace_array *tr);
394         void                    (*stop)(struct trace_array *tr);
395         void                    (*open)(struct trace_iterator *iter);
396         void                    (*pipe_open)(struct trace_iterator *iter);
397         void                    (*wait_pipe)(struct trace_iterator *iter);
398         void                    (*close)(struct trace_iterator *iter);
399         ssize_t                 (*read)(struct trace_iterator *iter,
400                                         struct file *filp, char __user *ubuf,
401                                         size_t cnt, loff_t *ppos);
402         ssize_t                 (*splice_read)(struct trace_iterator *iter,
403                                                struct file *filp,
404                                                loff_t *ppos,
405                                                struct pipe_inode_info *pipe,
406                                                size_t len,
407                                                unsigned int flags);
408 #ifdef CONFIG_FTRACE_STARTUP_TEST
409         int                     (*selftest)(struct tracer *trace,
410                                             struct trace_array *tr);
411 #endif
412         void                    (*print_header)(struct seq_file *m);
413         enum print_line_t       (*print_line)(struct trace_iterator *iter);
414         /* If you handled the flag setting, return 0 */
415         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
416         struct tracer           *next;
417         int                     print_max;
418         struct tracer_flags     *flags;
419         struct tracer_stat      *stats;
420 };
421
422 struct trace_seq {
423         unsigned char           buffer[PAGE_SIZE];
424         unsigned int            len;
425         unsigned int            readpos;
426 };
427
428 static inline void
429 trace_seq_init(struct trace_seq *s)
430 {
431         s->len = 0;
432         s->readpos = 0;
433 }
434
435
436 #define TRACE_PIPE_ALL_CPU      -1
437
438 /*
439  * Trace iterator - used by printout routines who present trace
440  * results to users and which routines might sleep, etc:
441  */
442 struct trace_iterator {
443         struct trace_array      *tr;
444         struct tracer           *trace;
445         void                    *private;
446         int                     cpu_file;
447         struct mutex            mutex;
448         struct ring_buffer_iter *buffer_iter[NR_CPUS];
449
450         /* The below is zeroed out in pipe_read */
451         struct trace_seq        seq;
452         struct trace_entry      *ent;
453         int                     cpu;
454         u64                     ts;
455
456         unsigned long           iter_flags;
457         loff_t                  pos;
458         long                    idx;
459
460         cpumask_var_t           started;
461 };
462
463 int tracer_init(struct tracer *t, struct trace_array *tr);
464 int tracing_is_enabled(void);
465 void trace_wake_up(void);
466 void tracing_reset(struct trace_array *tr, int cpu);
467 void tracing_reset_online_cpus(struct trace_array *tr);
468 int tracing_open_generic(struct inode *inode, struct file *filp);
469 struct dentry *tracing_init_dentry(void);
470 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
471
472 struct ring_buffer_event;
473
474 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
475                                                     unsigned char type,
476                                                     unsigned long len,
477                                                     unsigned long flags,
478                                                     int pc);
479 void trace_buffer_unlock_commit(struct trace_array *tr,
480                                 struct ring_buffer_event *event,
481                                 unsigned long flags, int pc);
482
483 struct ring_buffer_event *
484 trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
485                                   unsigned long flags, int pc);
486 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
487                                         unsigned long flags, int pc);
488
489 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
490                                                 struct trace_array_cpu *data);
491
492 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
493                                           int *ent_cpu, u64 *ent_ts);
494
495 void tracing_generic_entry_update(struct trace_entry *entry,
496                                   unsigned long flags,
497                                   int pc);
498
499 void default_wait_pipe(struct trace_iterator *iter);
500 void poll_wait_pipe(struct trace_iterator *iter);
501
502 void ftrace(struct trace_array *tr,
503                             struct trace_array_cpu *data,
504                             unsigned long ip,
505                             unsigned long parent_ip,
506                             unsigned long flags, int pc);
507 void tracing_sched_switch_trace(struct trace_array *tr,
508                                 struct task_struct *prev,
509                                 struct task_struct *next,
510                                 unsigned long flags, int pc);
511 void tracing_record_cmdline(struct task_struct *tsk);
512
513 void tracing_sched_wakeup_trace(struct trace_array *tr,
514                                 struct task_struct *wakee,
515                                 struct task_struct *cur,
516                                 unsigned long flags, int pc);
517 void trace_special(struct trace_array *tr,
518                    struct trace_array_cpu *data,
519                    unsigned long arg1,
520                    unsigned long arg2,
521                    unsigned long arg3, int pc);
522 void trace_function(struct trace_array *tr,
523                     unsigned long ip,
524                     unsigned long parent_ip,
525                     unsigned long flags, int pc);
526
527 void trace_graph_return(struct ftrace_graph_ret *trace);
528 int trace_graph_entry(struct ftrace_graph_ent *trace);
529
530 void tracing_start_cmdline_record(void);
531 void tracing_stop_cmdline_record(void);
532 void tracing_sched_switch_assign_trace(struct trace_array *tr);
533 void tracing_stop_sched_switch_record(void);
534 void tracing_start_sched_switch_record(void);
535 int register_tracer(struct tracer *type);
536 void unregister_tracer(struct tracer *type);
537
538 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
539
540 extern unsigned long tracing_max_latency;
541 extern unsigned long tracing_thresh;
542
543 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
544 void update_max_tr_single(struct trace_array *tr,
545                           struct task_struct *tsk, int cpu);
546
547 void __trace_stack(struct trace_array *tr,
548                    unsigned long flags,
549                    int skip, int pc);
550
551 extern cycle_t ftrace_now(int cpu);
552
553 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
554 typedef void
555 (*tracer_switch_func_t)(void *private,
556                         void *__rq,
557                         struct task_struct *prev,
558                         struct task_struct *next);
559
560 struct tracer_switch_ops {
561         tracer_switch_func_t            func;
562         void                            *private;
563         struct tracer_switch_ops        *next;
564 };
565 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
566
567 extern char *trace_find_cmdline(int pid);
568
569 #ifdef CONFIG_DYNAMIC_FTRACE
570 extern unsigned long ftrace_update_tot_cnt;
571 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
572 extern int DYN_FTRACE_TEST_NAME(void);
573 #endif
574
575 #ifdef CONFIG_FTRACE_STARTUP_TEST
576 extern int trace_selftest_startup_function(struct tracer *trace,
577                                            struct trace_array *tr);
578 extern int trace_selftest_startup_function_graph(struct tracer *trace,
579                                                  struct trace_array *tr);
580 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
581                                           struct trace_array *tr);
582 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
583                                              struct trace_array *tr);
584 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
585                                                  struct trace_array *tr);
586 extern int trace_selftest_startup_wakeup(struct tracer *trace,
587                                          struct trace_array *tr);
588 extern int trace_selftest_startup_nop(struct tracer *trace,
589                                          struct trace_array *tr);
590 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
591                                                struct trace_array *tr);
592 extern int trace_selftest_startup_sysprof(struct tracer *trace,
593                                                struct trace_array *tr);
594 extern int trace_selftest_startup_branch(struct tracer *trace,
595                                          struct trace_array *tr);
596 #endif /* CONFIG_FTRACE_STARTUP_TEST */
597
598 extern void *head_page(struct trace_array_cpu *data);
599 extern long ns2usecs(cycle_t nsec);
600 extern int
601 trace_vbprintk(unsigned long ip, int depth, const char *fmt, va_list args);
602 extern int
603 trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args);
604
605 extern unsigned long trace_flags;
606
607 /* Standard output formatting function used for function return traces */
608 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
609 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
610
611 #ifdef CONFIG_DYNAMIC_FTRACE
612 /* TODO: make this variable */
613 #define FTRACE_GRAPH_MAX_FUNCS          32
614 extern int ftrace_graph_count;
615 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
616
617 static inline int ftrace_graph_addr(unsigned long addr)
618 {
619         int i;
620
621         if (!ftrace_graph_count || test_tsk_trace_graph(current))
622                 return 1;
623
624         for (i = 0; i < ftrace_graph_count; i++) {
625                 if (addr == ftrace_graph_funcs[i])
626                         return 1;
627         }
628
629         return 0;
630 }
631 #else
632 static inline int ftrace_trace_addr(unsigned long addr)
633 {
634         return 1;
635 }
636 static inline int ftrace_graph_addr(unsigned long addr)
637 {
638         return 1;
639 }
640 #endif /* CONFIG_DYNAMIC_FTRACE */
641
642 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
643 static inline enum print_line_t
644 print_graph_function(struct trace_iterator *iter)
645 {
646         return TRACE_TYPE_UNHANDLED;
647 }
648 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
649
650 extern struct pid *ftrace_pid_trace;
651
652 static inline int ftrace_trace_task(struct task_struct *task)
653 {
654         if (!ftrace_pid_trace)
655                 return 1;
656
657         return test_tsk_trace_trace(task);
658 }
659
660 /*
661  * trace_iterator_flags is an enumeration that defines bit
662  * positions into trace_flags that controls the output.
663  *
664  * NOTE: These bits must match the trace_options array in
665  *       trace.c.
666  */
667 enum trace_iterator_flags {
668         TRACE_ITER_PRINT_PARENT         = 0x01,
669         TRACE_ITER_SYM_OFFSET           = 0x02,
670         TRACE_ITER_SYM_ADDR             = 0x04,
671         TRACE_ITER_VERBOSE              = 0x08,
672         TRACE_ITER_RAW                  = 0x10,
673         TRACE_ITER_HEX                  = 0x20,
674         TRACE_ITER_BIN                  = 0x40,
675         TRACE_ITER_BLOCK                = 0x80,
676         TRACE_ITER_STACKTRACE           = 0x100,
677         TRACE_ITER_SCHED_TREE           = 0x200,
678         TRACE_ITER_PRINTK               = 0x400,
679         TRACE_ITER_PREEMPTONLY          = 0x800,
680         TRACE_ITER_BRANCH               = 0x1000,
681         TRACE_ITER_ANNOTATE             = 0x2000,
682         TRACE_ITER_USERSTACKTRACE       = 0x4000,
683         TRACE_ITER_SYM_USEROBJ          = 0x8000,
684         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
685         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
686         TRACE_ITER_LATENCY_FMT          = 0x40000,
687 };
688
689 /*
690  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
691  * control the output of kernel symbols.
692  */
693 #define TRACE_ITER_SYM_MASK \
694         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
695
696 extern struct tracer nop_trace;
697
698 /**
699  * ftrace_preempt_disable - disable preemption scheduler safe
700  *
701  * When tracing can happen inside the scheduler, there exists
702  * cases that the tracing might happen before the need_resched
703  * flag is checked. If this happens and the tracer calls
704  * preempt_enable (after a disable), a schedule might take place
705  * causing an infinite recursion.
706  *
707  * To prevent this, we read the need_resched flag before
708  * disabling preemption. When we want to enable preemption we
709  * check the flag, if it is set, then we call preempt_enable_no_resched.
710  * Otherwise, we call preempt_enable.
711  *
712  * The rational for doing the above is that if need_resched is set
713  * and we have yet to reschedule, we are either in an atomic location
714  * (where we do not need to check for scheduling) or we are inside
715  * the scheduler and do not want to resched.
716  */
717 static inline int ftrace_preempt_disable(void)
718 {
719         int resched;
720
721         resched = need_resched();
722         preempt_disable_notrace();
723
724         return resched;
725 }
726
727 /**
728  * ftrace_preempt_enable - enable preemption scheduler safe
729  * @resched: the return value from ftrace_preempt_disable
730  *
731  * This is a scheduler safe way to enable preemption and not miss
732  * any preemption checks. The disabled saved the state of preemption.
733  * If resched is set, then we are either inside an atomic or
734  * are inside the scheduler (we would have already scheduled
735  * otherwise). In this case, we do not want to call normal
736  * preempt_enable, but preempt_enable_no_resched instead.
737  */
738 static inline void ftrace_preempt_enable(int resched)
739 {
740         if (resched)
741                 preempt_enable_no_resched_notrace();
742         else
743                 preempt_enable_notrace();
744 }
745
746 #ifdef CONFIG_BRANCH_TRACER
747 extern int enable_branch_tracing(struct trace_array *tr);
748 extern void disable_branch_tracing(void);
749 static inline int trace_branch_enable(struct trace_array *tr)
750 {
751         if (trace_flags & TRACE_ITER_BRANCH)
752                 return enable_branch_tracing(tr);
753         return 0;
754 }
755 static inline void trace_branch_disable(void)
756 {
757         /* due to races, always disable */
758         disable_branch_tracing();
759 }
760 #else
761 static inline int trace_branch_enable(struct trace_array *tr)
762 {
763         return 0;
764 }
765 static inline void trace_branch_disable(void)
766 {
767 }
768 #endif /* CONFIG_BRANCH_TRACER */
769
770 /* set ring buffers to default size if not already done so */
771 int tracing_update_buffers(void);
772
773 /* trace event type bit fields, not numeric */
774 enum {
775         TRACE_EVENT_TYPE_PRINTF         = 1,
776         TRACE_EVENT_TYPE_RAW            = 2,
777 };
778
779 struct ftrace_event_call {
780         char            *name;
781         char            *system;
782         struct dentry   *dir;
783         int             enabled;
784         int             (*regfunc)(void);
785         void            (*unregfunc)(void);
786         int             id;
787         int             (*raw_init)(void);
788         int             (*show_format)(struct trace_seq *s);
789 };
790
791 void event_trace_printk(unsigned long ip, const char *fmt, ...);
792 extern struct ftrace_event_call __start_ftrace_events[];
793 extern struct ftrace_event_call __stop_ftrace_events[];
794
795 extern const char *__start___trace_bprintk_fmt[];
796 extern const char *__stop___trace_bprintk_fmt[];
797
798 /*
799  * The double __builtin_constant_p is because gcc will give us an error
800  * if we try to allocate the static variable to fmt if it is not a
801  * constant. Even with the outer if statement optimizing out.
802  */
803 #define event_trace_printk(ip, fmt, args...)                            \
804 do {                                                                    \
805         __trace_printk_check_format(fmt, ##args);                       \
806         tracing_record_cmdline(current);                                \
807         if (__builtin_constant_p(fmt)) {                                \
808                 static const char *trace_printk_fmt                     \
809                   __attribute__((section("__trace_printk_fmt"))) =      \
810                         __builtin_constant_p(fmt) ? fmt : NULL;         \
811                                                                         \
812                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
813         } else                                                          \
814                 __trace_printk(ip, fmt, ##args);                        \
815 } while (0)
816
817 #endif /* _LINUX_KERNEL_TRACE_H */