trace.h 22 KB

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