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