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