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