Merge branch 'linus' into tracing/hw-branch-tracing
[sfrench/cifs-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         const char              *fmt;
127         u32                     buf[];
128 };
129
130 struct print_entry {
131         struct trace_entry      ent;
132         unsigned long           ip;
133         char                    buf[];
134 };
135
136 #define TRACE_OLD_SIZE          88
137
138 struct trace_field_cont {
139         unsigned char           type;
140         /* Temporary till we get rid of this completely */
141         char                    buf[TRACE_OLD_SIZE - 1];
142 };
143
144 struct trace_mmiotrace_rw {
145         struct trace_entry      ent;
146         struct mmiotrace_rw     rw;
147 };
148
149 struct trace_mmiotrace_map {
150         struct trace_entry      ent;
151         struct mmiotrace_map    map;
152 };
153
154 struct trace_boot_call {
155         struct trace_entry      ent;
156         struct boot_trace_call boot_call;
157 };
158
159 struct trace_boot_ret {
160         struct trace_entry      ent;
161         struct boot_trace_ret boot_ret;
162 };
163
164 #define TRACE_FUNC_SIZE 30
165 #define TRACE_FILE_SIZE 20
166 struct trace_branch {
167         struct trace_entry      ent;
168         unsigned                line;
169         char                    func[TRACE_FUNC_SIZE+1];
170         char                    file[TRACE_FILE_SIZE+1];
171         char                    correct;
172 };
173
174 struct hw_branch_entry {
175         struct trace_entry      ent;
176         u64                     from;
177         u64                     to;
178 };
179
180 struct trace_power {
181         struct trace_entry      ent;
182         struct power_trace      state_data;
183 };
184
185 enum kmemtrace_type_id {
186         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
187         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
188         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
189 };
190
191 struct kmemtrace_alloc_entry {
192         struct trace_entry      ent;
193         enum kmemtrace_type_id type_id;
194         unsigned long call_site;
195         const void *ptr;
196         size_t bytes_req;
197         size_t bytes_alloc;
198         gfp_t gfp_flags;
199         int node;
200 };
201
202 struct kmemtrace_free_entry {
203         struct trace_entry      ent;
204         enum kmemtrace_type_id type_id;
205         unsigned long call_site;
206         const void *ptr;
207 };
208
209 struct syscall_trace_enter {
210         struct trace_entry      ent;
211         int                     nr;
212         unsigned long           args[];
213 };
214
215 struct syscall_trace_exit {
216         struct trace_entry      ent;
217         int                     nr;
218         unsigned long           ret;
219 };
220
221
222 /*
223  * trace_flag_type is an enumeration that holds different
224  * states when a trace occurs. These are:
225  *  IRQS_OFF            - interrupts were disabled
226  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
227  *  NEED_RESCED         - reschedule is requested
228  *  HARDIRQ             - inside an interrupt handler
229  *  SOFTIRQ             - inside a softirq handler
230  */
231 enum trace_flag_type {
232         TRACE_FLAG_IRQS_OFF             = 0x01,
233         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
234         TRACE_FLAG_NEED_RESCHED         = 0x04,
235         TRACE_FLAG_HARDIRQ              = 0x08,
236         TRACE_FLAG_SOFTIRQ              = 0x10,
237 };
238
239 #define TRACE_BUF_SIZE          1024
240
241 /*
242  * The CPU trace array - it consists of thousands of trace entries
243  * plus some other descriptor data: (for example which task started
244  * the trace, etc.)
245  */
246 struct trace_array_cpu {
247         atomic_t                disabled;
248         void                    *buffer_page;   /* ring buffer spare */
249
250         /* these fields get copied into max-trace: */
251         unsigned long           trace_idx;
252         unsigned long           overrun;
253         unsigned long           saved_latency;
254         unsigned long           critical_start;
255         unsigned long           critical_end;
256         unsigned long           critical_sequence;
257         unsigned long           nice;
258         unsigned long           policy;
259         unsigned long           rt_priority;
260         cycle_t                 preempt_timestamp;
261         pid_t                   pid;
262         uid_t                   uid;
263         char                    comm[TASK_COMM_LEN];
264 };
265
266 struct trace_iterator;
267
268 /*
269  * The trace array - an array of per-CPU trace arrays. This is the
270  * highest level data structure that individual tracers deal with.
271  * They have on/off state as well:
272  */
273 struct trace_array {
274         struct ring_buffer      *buffer;
275         unsigned long           entries;
276         int                     cpu;
277         cycle_t                 time_start;
278         struct task_struct      *waiter;
279         struct trace_array_cpu  *data[NR_CPUS];
280 };
281
282 #define FTRACE_CMP_TYPE(var, type) \
283         __builtin_types_compatible_p(typeof(var), type *)
284
285 #undef IF_ASSIGN
286 #define IF_ASSIGN(var, entry, etype, id)                \
287         if (FTRACE_CMP_TYPE(var, etype)) {              \
288                 var = (typeof(var))(entry);             \
289                 WARN_ON(id && (entry)->type != id);     \
290                 break;                                  \
291         }
292
293 /* Will cause compile errors if type is not found. */
294 extern void __ftrace_bad_type(void);
295
296 /*
297  * The trace_assign_type is a verifier that the entry type is
298  * the same as the type being assigned. To add new types simply
299  * add a line with the following format:
300  *
301  * IF_ASSIGN(var, ent, type, id);
302  *
303  *  Where "type" is the trace type that includes the trace_entry
304  *  as the "ent" item. And "id" is the trace identifier that is
305  *  used in the trace_type enum.
306  *
307  *  If the type can have more than one id, then use zero.
308  */
309 #define trace_assign_type(var, ent)                                     \
310         do {                                                            \
311                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
312                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
313                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
314                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
315                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
316                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
317                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
318                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
319                           TRACE_MMIO_RW);                               \
320                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
321                           TRACE_MMIO_MAP);                              \
322                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
323                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
324                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
325                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
326                           TRACE_GRAPH_ENT);             \
327                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
328                           TRACE_GRAPH_RET);             \
329                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
330                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
331                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
332                           TRACE_KMEM_ALLOC);    \
333                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
334                           TRACE_KMEM_FREE);     \
335                 IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
336                           TRACE_SYSCALL_ENTER);                         \
337                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
338                           TRACE_SYSCALL_EXIT);                          \
339                 __ftrace_bad_type();                                    \
340         } while (0)
341
342 /* Return values for print_line callback */
343 enum print_line_t {
344         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
345         TRACE_TYPE_HANDLED      = 1,
346         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
347         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
348 };
349
350
351 /*
352  * An option specific to a tracer. This is a boolean value.
353  * The bit is the bit index that sets its value on the
354  * flags value in struct tracer_flags.
355  */
356 struct tracer_opt {
357         const char      *name; /* Will appear on the trace_options file */
358         u32             bit; /* Mask assigned in val field in tracer_flags */
359 };
360
361 /*
362  * The set of specific options for a tracer. Your tracer
363  * have to set the initial value of the flags val.
364  */
365 struct tracer_flags {
366         u32                     val;
367         struct tracer_opt       *opts;
368 };
369
370 /* Makes more easy to define a tracer opt */
371 #define TRACER_OPT(s, b)        .name = #s, .bit = b
372
373
374 /**
375  * struct tracer - a specific tracer and its callbacks to interact with debugfs
376  * @name: the name chosen to select it on the available_tracers file
377  * @init: called when one switches to this tracer (echo name > current_tracer)
378  * @reset: called when one switches to another tracer
379  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
380  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
381  * @open: called when the trace file is opened
382  * @pipe_open: called when the trace_pipe file is opened
383  * @wait_pipe: override how the user waits for traces on trace_pipe
384  * @close: called when the trace file is released
385  * @read: override the default read callback on trace_pipe
386  * @splice_read: override the default splice_read callback on trace_pipe
387  * @selftest: selftest to run on boot (see trace_selftest.c)
388  * @print_headers: override the first lines that describe your columns
389  * @print_line: callback that prints a trace
390  * @set_flag: signals one of your private flags changed (trace_options file)
391  * @flags: your private flags
392  */
393 struct tracer {
394         const char              *name;
395         int                     (*init)(struct trace_array *tr);
396         void                    (*reset)(struct trace_array *tr);
397         void                    (*start)(struct trace_array *tr);
398         void                    (*stop)(struct trace_array *tr);
399         void                    (*open)(struct trace_iterator *iter);
400         void                    (*pipe_open)(struct trace_iterator *iter);
401         void                    (*wait_pipe)(struct trace_iterator *iter);
402         void                    (*close)(struct trace_iterator *iter);
403         ssize_t                 (*read)(struct trace_iterator *iter,
404                                         struct file *filp, char __user *ubuf,
405                                         size_t cnt, loff_t *ppos);
406         ssize_t                 (*splice_read)(struct trace_iterator *iter,
407                                                struct file *filp,
408                                                loff_t *ppos,
409                                                struct pipe_inode_info *pipe,
410                                                size_t len,
411                                                unsigned int flags);
412 #ifdef CONFIG_FTRACE_STARTUP_TEST
413         int                     (*selftest)(struct tracer *trace,
414                                             struct trace_array *tr);
415 #endif
416         void                    (*print_header)(struct seq_file *m);
417         enum print_line_t       (*print_line)(struct trace_iterator *iter);
418         /* If you handled the flag setting, return 0 */
419         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
420         struct tracer           *next;
421         int                     print_max;
422         struct tracer_flags     *flags;
423         struct tracer_stat      *stats;
424 };
425
426 struct trace_seq {
427         unsigned char           buffer[PAGE_SIZE];
428         unsigned int            len;
429         unsigned int            readpos;
430 };
431
432 static inline void
433 trace_seq_init(struct trace_seq *s)
434 {
435         s->len = 0;
436         s->readpos = 0;
437 }
438
439
440 #define TRACE_PIPE_ALL_CPU      -1
441
442 /*
443  * Trace iterator - used by printout routines who present trace
444  * results to users and which routines might sleep, etc:
445  */
446 struct trace_iterator {
447         struct trace_array      *tr;
448         struct tracer           *trace;
449         void                    *private;
450         int                     cpu_file;
451         struct mutex            mutex;
452         struct ring_buffer_iter *buffer_iter[NR_CPUS];
453
454         /* The below is zeroed out in pipe_read */
455         struct trace_seq        seq;
456         struct trace_entry      *ent;
457         int                     cpu;
458         u64                     ts;
459
460         unsigned long           iter_flags;
461         loff_t                  pos;
462         long                    idx;
463
464         cpumask_var_t           started;
465 };
466
467 int tracer_init(struct tracer *t, struct trace_array *tr);
468 int tracing_is_enabled(void);
469 void trace_wake_up(void);
470 void tracing_reset(struct trace_array *tr, int cpu);
471 void tracing_reset_online_cpus(struct trace_array *tr);
472 int tracing_open_generic(struct inode *inode, struct file *filp);
473 struct dentry *tracing_init_dentry(void);
474 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
475
476 struct ring_buffer_event;
477
478 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
479                                                     unsigned char type,
480                                                     unsigned long len,
481                                                     unsigned long flags,
482                                                     int pc);
483 void trace_buffer_unlock_commit(struct trace_array *tr,
484                                 struct ring_buffer_event *event,
485                                 unsigned long flags, int pc);
486
487 struct ring_buffer_event *
488 trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
489                                   unsigned long flags, int pc);
490 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
491                                         unsigned long flags, int pc);
492 void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
493                                         unsigned long flags, int pc);
494
495 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
496                                                 struct trace_array_cpu *data);
497
498 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
499                                           int *ent_cpu, u64 *ent_ts);
500
501 void tracing_generic_entry_update(struct trace_entry *entry,
502                                   unsigned long flags,
503                                   int pc);
504
505 void default_wait_pipe(struct trace_iterator *iter);
506 void poll_wait_pipe(struct trace_iterator *iter);
507
508 void ftrace(struct trace_array *tr,
509                             struct trace_array_cpu *data,
510                             unsigned long ip,
511                             unsigned long parent_ip,
512                             unsigned long flags, int pc);
513 void tracing_sched_switch_trace(struct trace_array *tr,
514                                 struct task_struct *prev,
515                                 struct task_struct *next,
516                                 unsigned long flags, int pc);
517 void tracing_record_cmdline(struct task_struct *tsk);
518
519 void tracing_sched_wakeup_trace(struct trace_array *tr,
520                                 struct task_struct *wakee,
521                                 struct task_struct *cur,
522                                 unsigned long flags, int pc);
523 void trace_special(struct trace_array *tr,
524                    struct trace_array_cpu *data,
525                    unsigned long arg1,
526                    unsigned long arg2,
527                    unsigned long arg3, int pc);
528 void trace_function(struct trace_array *tr,
529                     unsigned long ip,
530                     unsigned long parent_ip,
531                     unsigned long flags, int pc);
532
533 void trace_graph_return(struct ftrace_graph_ret *trace);
534 int trace_graph_entry(struct ftrace_graph_ent *trace);
535
536 void tracing_start_cmdline_record(void);
537 void tracing_stop_cmdline_record(void);
538 void tracing_sched_switch_assign_trace(struct trace_array *tr);
539 void tracing_stop_sched_switch_record(void);
540 void tracing_start_sched_switch_record(void);
541 int register_tracer(struct tracer *type);
542 void unregister_tracer(struct tracer *type);
543
544 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
545
546 extern unsigned long tracing_max_latency;
547 extern unsigned long tracing_thresh;
548
549 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
550 void update_max_tr_single(struct trace_array *tr,
551                           struct task_struct *tsk, int cpu);
552
553 void __trace_stack(struct trace_array *tr,
554                    unsigned long flags,
555                    int skip, int pc);
556
557 extern cycle_t ftrace_now(int cpu);
558
559 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
560 typedef void
561 (*tracer_switch_func_t)(void *private,
562                         void *__rq,
563                         struct task_struct *prev,
564                         struct task_struct *next);
565
566 struct tracer_switch_ops {
567         tracer_switch_func_t            func;
568         void                            *private;
569         struct tracer_switch_ops        *next;
570 };
571 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
572
573 extern void trace_find_cmdline(int pid, char comm[]);
574
575 #ifdef CONFIG_DYNAMIC_FTRACE
576 extern unsigned long ftrace_update_tot_cnt;
577 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
578 extern int DYN_FTRACE_TEST_NAME(void);
579 #endif
580
581 #ifdef CONFIG_FTRACE_STARTUP_TEST
582 extern int trace_selftest_startup_function(struct tracer *trace,
583                                            struct trace_array *tr);
584 extern int trace_selftest_startup_function_graph(struct tracer *trace,
585                                                  struct trace_array *tr);
586 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
587                                           struct trace_array *tr);
588 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
589                                              struct trace_array *tr);
590 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
591                                                  struct trace_array *tr);
592 extern int trace_selftest_startup_wakeup(struct tracer *trace,
593                                          struct trace_array *tr);
594 extern int trace_selftest_startup_nop(struct tracer *trace,
595                                          struct trace_array *tr);
596 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
597                                                struct trace_array *tr);
598 extern int trace_selftest_startup_sysprof(struct tracer *trace,
599                                                struct trace_array *tr);
600 extern int trace_selftest_startup_branch(struct tracer *trace,
601                                          struct trace_array *tr);
602 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
603                                               struct trace_array *tr);
604 #endif /* CONFIG_FTRACE_STARTUP_TEST */
605
606 extern void *head_page(struct trace_array_cpu *data);
607 extern long ns2usecs(cycle_t nsec);
608 extern int
609 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
610 extern int
611 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
612
613 extern unsigned long trace_flags;
614
615 /* Standard output formatting function used for function return traces */
616 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
617 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
618
619 #ifdef CONFIG_DYNAMIC_FTRACE
620 /* TODO: make this variable */
621 #define FTRACE_GRAPH_MAX_FUNCS          32
622 extern int ftrace_graph_count;
623 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
624
625 static inline int ftrace_graph_addr(unsigned long addr)
626 {
627         int i;
628
629         if (!ftrace_graph_count || test_tsk_trace_graph(current))
630                 return 1;
631
632         for (i = 0; i < ftrace_graph_count; i++) {
633                 if (addr == ftrace_graph_funcs[i])
634                         return 1;
635         }
636
637         return 0;
638 }
639 #else
640 static inline int ftrace_trace_addr(unsigned long addr)
641 {
642         return 1;
643 }
644 static inline int ftrace_graph_addr(unsigned long addr)
645 {
646         return 1;
647 }
648 #endif /* CONFIG_DYNAMIC_FTRACE */
649
650 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
651 static inline enum print_line_t
652 print_graph_function(struct trace_iterator *iter)
653 {
654         return TRACE_TYPE_UNHANDLED;
655 }
656 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
657
658 extern struct pid *ftrace_pid_trace;
659
660 static inline int ftrace_trace_task(struct task_struct *task)
661 {
662         if (!ftrace_pid_trace)
663                 return 1;
664
665         return test_tsk_trace_trace(task);
666 }
667
668 /*
669  * trace_iterator_flags is an enumeration that defines bit
670  * positions into trace_flags that controls the output.
671  *
672  * NOTE: These bits must match the trace_options array in
673  *       trace.c.
674  */
675 enum trace_iterator_flags {
676         TRACE_ITER_PRINT_PARENT         = 0x01,
677         TRACE_ITER_SYM_OFFSET           = 0x02,
678         TRACE_ITER_SYM_ADDR             = 0x04,
679         TRACE_ITER_VERBOSE              = 0x08,
680         TRACE_ITER_RAW                  = 0x10,
681         TRACE_ITER_HEX                  = 0x20,
682         TRACE_ITER_BIN                  = 0x40,
683         TRACE_ITER_BLOCK                = 0x80,
684         TRACE_ITER_STACKTRACE           = 0x100,
685         TRACE_ITER_SCHED_TREE           = 0x200,
686         TRACE_ITER_PRINTK               = 0x400,
687         TRACE_ITER_PREEMPTONLY          = 0x800,
688         TRACE_ITER_BRANCH               = 0x1000,
689         TRACE_ITER_ANNOTATE             = 0x2000,
690         TRACE_ITER_USERSTACKTRACE       = 0x4000,
691         TRACE_ITER_SYM_USEROBJ          = 0x8000,
692         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
693         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
694         TRACE_ITER_LATENCY_FMT          = 0x40000,
695         TRACE_ITER_GLOBAL_CLK           = 0x80000,
696         TRACE_ITER_SLEEP_TIME           = 0x100000,
697 };
698
699 /*
700  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
701  * control the output of kernel symbols.
702  */
703 #define TRACE_ITER_SYM_MASK \
704         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
705
706 extern struct tracer nop_trace;
707
708 /**
709  * ftrace_preempt_disable - disable preemption scheduler safe
710  *
711  * When tracing can happen inside the scheduler, there exists
712  * cases that the tracing might happen before the need_resched
713  * flag is checked. If this happens and the tracer calls
714  * preempt_enable (after a disable), a schedule might take place
715  * causing an infinite recursion.
716  *
717  * To prevent this, we read the need_resched flag before
718  * disabling preemption. When we want to enable preemption we
719  * check the flag, if it is set, then we call preempt_enable_no_resched.
720  * Otherwise, we call preempt_enable.
721  *
722  * The rational for doing the above is that if need_resched is set
723  * and we have yet to reschedule, we are either in an atomic location
724  * (where we do not need to check for scheduling) or we are inside
725  * the scheduler and do not want to resched.
726  */
727 static inline int ftrace_preempt_disable(void)
728 {
729         int resched;
730
731         resched = need_resched();
732         preempt_disable_notrace();
733
734         return resched;
735 }
736
737 /**
738  * ftrace_preempt_enable - enable preemption scheduler safe
739  * @resched: the return value from ftrace_preempt_disable
740  *
741  * This is a scheduler safe way to enable preemption and not miss
742  * any preemption checks. The disabled saved the state of preemption.
743  * If resched is set, then we are either inside an atomic or
744  * are inside the scheduler (we would have already scheduled
745  * otherwise). In this case, we do not want to call normal
746  * preempt_enable, but preempt_enable_no_resched instead.
747  */
748 static inline void ftrace_preempt_enable(int resched)
749 {
750         if (resched)
751                 preempt_enable_no_resched_notrace();
752         else
753                 preempt_enable_notrace();
754 }
755
756 #ifdef CONFIG_BRANCH_TRACER
757 extern int enable_branch_tracing(struct trace_array *tr);
758 extern void disable_branch_tracing(void);
759 static inline int trace_branch_enable(struct trace_array *tr)
760 {
761         if (trace_flags & TRACE_ITER_BRANCH)
762                 return enable_branch_tracing(tr);
763         return 0;
764 }
765 static inline void trace_branch_disable(void)
766 {
767         /* due to races, always disable */
768         disable_branch_tracing();
769 }
770 #else
771 static inline int trace_branch_enable(struct trace_array *tr)
772 {
773         return 0;
774 }
775 static inline void trace_branch_disable(void)
776 {
777 }
778 #endif /* CONFIG_BRANCH_TRACER */
779
780 /* set ring buffers to default size if not already done so */
781 int tracing_update_buffers(void);
782
783 /* trace event type bit fields, not numeric */
784 enum {
785         TRACE_EVENT_TYPE_PRINTF         = 1,
786         TRACE_EVENT_TYPE_RAW            = 2,
787 };
788
789 struct ftrace_event_field {
790         struct list_head        link;
791         char                    *name;
792         char                    *type;
793         int                     offset;
794         int                     size;
795 };
796
797 struct ftrace_event_call {
798         char                    *name;
799         char                    *system;
800         struct dentry           *dir;
801         int                     enabled;
802         int                     (*regfunc)(void);
803         void                    (*unregfunc)(void);
804         int                     id;
805         int                     (*raw_init)(void);
806         int                     (*show_format)(struct trace_seq *s);
807         int                     (*define_fields)(void);
808         struct list_head        fields;
809         struct filter_pred      **preds;
810
811 #ifdef CONFIG_EVENT_PROFILE
812         atomic_t        profile_count;
813         int             (*profile_enable)(struct ftrace_event_call *);
814         void            (*profile_disable)(struct ftrace_event_call *);
815 #endif
816 };
817
818 struct event_subsystem {
819         struct list_head        list;
820         const char              *name;
821         struct dentry           *entry;
822         struct filter_pred      **preds;
823 };
824
825 #define events_for_each(event)                                          \
826         for (event = __start_ftrace_events;                             \
827              (unsigned long)event < (unsigned long)__stop_ftrace_events; \
828              event++)
829
830 #define MAX_FILTER_PRED 8
831
832 struct filter_pred;
833
834 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
835
836 struct filter_pred {
837         filter_pred_fn_t fn;
838         u64 val;
839         char *str_val;
840         int str_len;
841         char *field_name;
842         int offset;
843         int not;
844         int or;
845         int compound;
846         int clear;
847 };
848
849 int trace_define_field(struct ftrace_event_call *call, char *type,
850                        char *name, int offset, int size);
851 extern void filter_free_pred(struct filter_pred *pred);
852 extern void filter_print_preds(struct filter_pred **preds,
853                                struct trace_seq *s);
854 extern int filter_parse(char **pbuf, struct filter_pred *pred);
855 extern int filter_add_pred(struct ftrace_event_call *call,
856                            struct filter_pred *pred);
857 extern void filter_free_preds(struct ftrace_event_call *call);
858 extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
859 extern void filter_free_subsystem_preds(struct event_subsystem *system);
860 extern int filter_add_subsystem_pred(struct event_subsystem *system,
861                                      struct filter_pred *pred);
862
863 void event_trace_printk(unsigned long ip, const char *fmt, ...);
864 extern struct ftrace_event_call __start_ftrace_events[];
865 extern struct ftrace_event_call __stop_ftrace_events[];
866
867 #define for_each_event(event)                                           \
868         for (event = __start_ftrace_events;                             \
869              (unsigned long)event < (unsigned long)__stop_ftrace_events; \
870              event++)
871
872 extern const char *__start___trace_bprintk_fmt[];
873 extern const char *__stop___trace_bprintk_fmt[];
874
875 /*
876  * The double __builtin_constant_p is because gcc will give us an error
877  * if we try to allocate the static variable to fmt if it is not a
878  * constant. Even with the outer if statement optimizing out.
879  */
880 #define event_trace_printk(ip, fmt, args...)                            \
881 do {                                                                    \
882         __trace_printk_check_format(fmt, ##args);                       \
883         tracing_record_cmdline(current);                                \
884         if (__builtin_constant_p(fmt)) {                                \
885                 static const char *trace_printk_fmt                     \
886                   __attribute__((section("__trace_printk_fmt"))) =      \
887                         __builtin_constant_p(fmt) ? fmt : NULL;         \
888                                                                         \
889                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
890         } else                                                          \
891                 __trace_printk(ip, fmt, ##args);                        \
892 } while (0)
893
894 #endif /* _LINUX_KERNEL_TRACE_H */