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/tracepoint.h>
  11 #include <linux/ftrace.h>
  12 #include <trace/boot.h>
  13 #include <linux/kmemtrace.h>
  14 #include <linux/hw_breakpoint.h>
  15
  16 #include <linux/trace_seq.h>
  17 #include <linux/ftrace_event.h>
  18
  19 enum trace_type {
  20         __TRACE_FIRST_TYPE = 0,
  21
  22         TRACE_FN,
  23         TRACE_CTX,
  24         TRACE_WAKE,
  25         TRACE_STACK,
  26         TRACE_PRINT,
  27         TRACE_BPRINT,
  28         TRACE_SPECIAL,
  29         TRACE_MMIO_RW,
  30         TRACE_MMIO_MAP,
  31         TRACE_BRANCH,
  32         TRACE_BOOT_CALL,
  33         TRACE_BOOT_RET,
  34         TRACE_GRAPH_RET,
  35         TRACE_GRAPH_ENT,
  36         TRACE_USER_STACK,
  37         TRACE_KMEM_ALLOC,
  38         TRACE_KMEM_FREE,
  39         TRACE_BLK,
  40         TRACE_KSYM,
  41
  42         __TRACE_LAST_TYPE,
  43 };
  44
  45 enum kmemtrace_type_id {
  46         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
  47         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
  48         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
  49 };
  50
  51 extern struct tracer boot_tracer;
  52
  53 #undef __field
  54 #define __field(type, item)             type    item;
  55
  56 #undef __field_struct
  57 #define __field_struct(type, item)      __field(type, item)
  58
  59 #undef __field_desc
  60 #define __field_desc(type, container, item)
  61
  62 #undef __array
  63 #define __array(type, item, size)       type    item[size];
  64
  65 #undef __array_desc
  66 #define __array_desc(type, container, item, size)
  67
  68 #undef __dynamic_array
  69 #define __dynamic_array(type, item)     type    item[];
  70
  71 #undef F_STRUCT
  72 #define F_STRUCT(args...)               args
  73
  74 #undef FTRACE_ENTRY
  75 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)     \
  76         struct struct_name {                                    \
  77                 struct trace_entry      ent;                    \
  78                 tstruct                                         \
  79         }
  80
  81 #undef TP_ARGS
  82 #define TP_ARGS(args...)        args
  83
  84 #undef FTRACE_ENTRY_DUP
  85 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
  86
  87 #include "trace_entries.h"
  88
  89 /*
  90  * syscalls are special, and need special handling, this is why
  91  * they are not included in trace_entries.h
  92  */
  93 struct syscall_trace_enter {
  94         struct trace_entry      ent;
  95         int                     nr;
  96         unsigned long           args[];
  97 };
  98
  99 struct syscall_trace_exit {
 100         struct trace_entry      ent;
 101         int                     nr;
 102         long                    ret;
 103 };
 104
 105 struct kprobe_trace_entry_head {
 106         struct trace_entry      ent;
 107         unsigned long           ip;
 108 };
 109
 110 struct kretprobe_trace_entry_head {
 111         struct trace_entry      ent;
 112         unsigned long           func;
 113         unsigned long           ret_ip;
 114 };
 115
 116 /*
 117  * trace_flag_type is an enumeration that holds different
 118  * states when a trace occurs. These are:
 119  *  IRQS_OFF            - interrupts were disabled
 120  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 121  *  NEED_RESCHED        - reschedule is requested
 122  *  HARDIRQ             - inside an interrupt handler
 123  *  SOFTIRQ             - inside a softirq handler
 124  */
 125 enum trace_flag_type {
 126         TRACE_FLAG_IRQS_OFF             = 0x01,
 127         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 128         TRACE_FLAG_NEED_RESCHED         = 0x04,
 129         TRACE_FLAG_HARDIRQ              = 0x08,
 130         TRACE_FLAG_SOFTIRQ              = 0x10,
 131 };
 132
 133 #define TRACE_BUF_SIZE          1024
 134
 135 /*
 136  * The CPU trace array - it consists of thousands of trace entries
 137  * plus some other descriptor data: (for example which task started
 138  * the trace, etc.)
 139  */
 140 struct trace_array_cpu {
 141         atomic_t                disabled;
 142         void                    *buffer_page;   /* ring buffer spare */
 143
 144         unsigned long           saved_latency;
 145         unsigned long           critical_start;
 146         unsigned long           critical_end;
 147         unsigned long           critical_sequence;
 148         unsigned long           nice;
 149         unsigned long           policy;
 150         unsigned long           rt_priority;
 151         unsigned long           skipped_entries;
 152         cycle_t                 preempt_timestamp;
 153         pid_t                   pid;
 154         uid_t                   uid;
 155         char                    comm[TASK_COMM_LEN];
 156 };
 157
 158 /*
 159  * The trace array - an array of per-CPU trace arrays. This is the
 160  * highest level data structure that individual tracers deal with.
 161  * They have on/off state as well:
 162  */
 163 struct trace_array {
 164         struct ring_buffer      *buffer;
 165         unsigned long           entries;
 166         int                     cpu;
 167         cycle_t                 time_start;
 168         struct task_struct      *waiter;
 169         struct trace_array_cpu  *data[NR_CPUS];
 170 };
 171
 172 #define FTRACE_CMP_TYPE(var, type) \
 173         __builtin_types_compatible_p(typeof(var), type *)
 174
 175 #undef IF_ASSIGN
 176 #define IF_ASSIGN(var, entry, etype, id)                \
 177         if (FTRACE_CMP_TYPE(var, etype)) {              \
 178                 var = (typeof(var))(entry);             \
 179                 WARN_ON(id && (entry)->type != id);     \
 180                 break;                                  \
 181         }
 182
 183 /* Will cause compile errors if type is not found. */
 184 extern void __ftrace_bad_type(void);
 185
 186 /*
 187  * The trace_assign_type is a verifier that the entry type is
 188  * the same as the type being assigned. To add new types simply
 189  * add a line with the following format:
 190  *
 191  * IF_ASSIGN(var, ent, type, id);
 192  *
 193  *  Where "type" is the trace type that includes the trace_entry
 194  *  as the "ent" item. And "id" is the trace identifier that is
 195  *  used in the trace_type enum.
 196  *
 197  *  If the type can have more than one id, then use zero.
 198  */
 199 #define trace_assign_type(var, ent)                                     \
 200         do {                                                            \
 201                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 202                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 203                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 204                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 205                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 206                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 207                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 208                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 209                           TRACE_MMIO_RW);                               \
 210                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 211                           TRACE_MMIO_MAP);                              \
 212                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 213                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 214                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 215                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 216                           TRACE_GRAPH_ENT);             \
 217                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 218                           TRACE_GRAPH_RET);             \
 219                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 220                           TRACE_KMEM_ALLOC);    \
 221                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 222                           TRACE_KMEM_FREE);     \
 223                 IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\
 224                 __ftrace_bad_type();                                    \
 225         } while (0)
 226
 227 /*
 228  * An option specific to a tracer. This is a boolean value.
 229  * The bit is the bit index that sets its value on the
 230  * flags value in struct tracer_flags.
 231  */
 232 struct tracer_opt {
 233         const char      *name; /* Will appear on the trace_options file */
 234         u32             bit; /* Mask assigned in val field in tracer_flags */
 235 };
 236
 237 /*
 238  * The set of specific options for a tracer. Your tracer
 239  * have to set the initial value of the flags val.
 240  */
 241 struct tracer_flags {
 242         u32                     val;
 243         struct tracer_opt       *opts;
 244 };
 245
 246 /* Makes more easy to define a tracer opt */
 247 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 248
 249
 250 /**
 251  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 252  * @name: the name chosen to select it on the available_tracers file
 253  * @init: called when one switches to this tracer (echo name > current_tracer)
 254  * @reset: called when one switches to another tracer
 255  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 256  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 257  * @open: called when the trace file is opened
 258  * @pipe_open: called when the trace_pipe file is opened
 259  * @wait_pipe: override how the user waits for traces on trace_pipe
 260  * @close: called when the trace file is released
 261  * @pipe_close: called when the trace_pipe file is released
 262  * @read: override the default read callback on trace_pipe
 263  * @splice_read: override the default splice_read callback on trace_pipe
 264  * @selftest: selftest to run on boot (see trace_selftest.c)
 265  * @print_headers: override the first lines that describe your columns
 266  * @print_line: callback that prints a trace
 267  * @set_flag: signals one of your private flags changed (trace_options file)
 268  * @flags: your private flags
 269  */
 270 struct tracer {
 271         const char              *name;
 272         int                     (*init)(struct trace_array *tr);
 273         void                    (*reset)(struct trace_array *tr);
 274         void                    (*start)(struct trace_array *tr);
 275         void                    (*stop)(struct trace_array *tr);
 276         void                    (*open)(struct trace_iterator *iter);
 277         void                    (*pipe_open)(struct trace_iterator *iter);
 278         void                    (*wait_pipe)(struct trace_iterator *iter);
 279         void                    (*close)(struct trace_iterator *iter);
 280         void                    (*pipe_close)(struct trace_iterator *iter);
 281         ssize_t                 (*read)(struct trace_iterator *iter,
 282                                         struct file *filp, char __user *ubuf,
 283                                         size_t cnt, loff_t *ppos);
 284         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 285                                                struct file *filp,
 286                                                loff_t *ppos,
 287                                                struct pipe_inode_info *pipe,
 288                                                size_t len,
 289                                                unsigned int flags);
 290 #ifdef CONFIG_FTRACE_STARTUP_TEST
 291         int                     (*selftest)(struct tracer *trace,
 292                                             struct trace_array *tr);
 293 #endif
 294         void                    (*print_header)(struct seq_file *m);
 295         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 296         /* If you handled the flag setting, return 0 */
 297         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 298         struct tracer           *next;
 299         int                     print_max;
 300         struct tracer_flags     *flags;
 301 };
 302
 303
 304 #define TRACE_PIPE_ALL_CPU      -1
 305
 306 int tracer_init(struct tracer *t, struct trace_array *tr);
 307 int tracing_is_enabled(void);
 308 void trace_wake_up(void);
 309 void tracing_reset(struct trace_array *tr, int cpu);
 310 void tracing_reset_online_cpus(struct trace_array *tr);
 311 void tracing_reset_current(int cpu);
 312 void tracing_reset_current_online_cpus(void);
 313 int tracing_open_generic(struct inode *inode, struct file *filp);
 314 struct dentry *trace_create_file(const char *name,
 315                                  mode_t mode,
 316                                  struct dentry *parent,
 317                                  void *data,
 318                                  const struct file_operations *fops);
 319
 320 struct dentry *tracing_init_dentry(void);
 321 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 322
 323 struct ring_buffer_event;
 324
 325 struct ring_buffer_event *
 326 trace_buffer_lock_reserve(struct ring_buffer *buffer,
 327                           int type,
 328                           unsigned long len,
 329                           unsigned long flags,
 330                           int pc);
 331 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
 332                                 struct ring_buffer_event *event,
 333                                 unsigned long flags, int pc);
 334
 335 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 336                                                 struct trace_array_cpu *data);
 337
 338 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 339                                           int *ent_cpu, u64 *ent_ts);
 340
 341 void default_wait_pipe(struct trace_iterator *iter);
 342 void poll_wait_pipe(struct trace_iterator *iter);
 343
 344 void ftrace(struct trace_array *tr,
 345                             struct trace_array_cpu *data,
 346                             unsigned long ip,
 347                             unsigned long parent_ip,
 348                             unsigned long flags, int pc);
 349 void tracing_sched_switch_trace(struct trace_array *tr,
 350                                 struct task_struct *prev,
 351                                 struct task_struct *next,
 352                                 unsigned long flags, int pc);
 353
 354 void tracing_sched_wakeup_trace(struct trace_array *tr,
 355                                 struct task_struct *wakee,
 356                                 struct task_struct *cur,
 357                                 unsigned long flags, int pc);
 358 void trace_special(struct trace_array *tr,
 359                    struct trace_array_cpu *data,
 360                    unsigned long arg1,
 361                    unsigned long arg2,
 362                    unsigned long arg3, int pc);
 363 void trace_function(struct trace_array *tr,
 364                     unsigned long ip,
 365                     unsigned long parent_ip,
 366                     unsigned long flags, int pc);
 367 void trace_default_header(struct seq_file *m);
 368 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
 369 int trace_empty(struct trace_iterator *iter);
 370
 371 void trace_graph_return(struct ftrace_graph_ret *trace);
 372 int trace_graph_entry(struct ftrace_graph_ent *trace);
 373 void set_graph_array(struct trace_array *tr);
 374
 375 void tracing_start_cmdline_record(void);
 376 void tracing_stop_cmdline_record(void);
 377 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 378 void tracing_stop_sched_switch_record(void);
 379 void tracing_start_sched_switch_record(void);
 380 int register_tracer(struct tracer *type);
 381 void unregister_tracer(struct tracer *type);
 382 int is_tracing_stopped(void);
 383
 384 extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr);
 385
 386 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 387
 388 extern unsigned long tracing_thresh;
 389
 390 #ifdef CONFIG_TRACER_MAX_TRACE
 391 extern unsigned long tracing_max_latency;
 392
 393 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 394 void update_max_tr_single(struct trace_array *tr,
 395                           struct task_struct *tsk, int cpu);
 396 #endif /* CONFIG_TRACER_MAX_TRACE */
 397
 398 #ifdef CONFIG_STACKTRACE
 399 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 400                         int skip, int pc);
 401
 402 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 403                             int pc);
 404
 405 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 406                    int pc);
 407 #else
 408 static inline void ftrace_trace_stack(struct ring_buffer *buffer,
 409                                       unsigned long flags, int skip, int pc)
 410 {
 411 }
 412
 413 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
 414                                           unsigned long flags, int pc)
 415 {
 416 }
 417
 418 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 419                                  int skip, int pc)
 420 {
 421 }
 422 #endif /* CONFIG_STACKTRACE */
 423
 424 extern cycle_t ftrace_now(int cpu);
 425
 426 extern void trace_find_cmdline(int pid, char comm[]);
 427
 428 #ifdef CONFIG_DYNAMIC_FTRACE
 429 extern unsigned long ftrace_update_tot_cnt;
 430 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 431 extern int DYN_FTRACE_TEST_NAME(void);
 432 #endif
 433
 434 extern int ring_buffer_expanded;
 435 extern bool tracing_selftest_disabled;
 436 DECLARE_PER_CPU(int, ftrace_cpu_disabled);
 437
 438 #ifdef CONFIG_FTRACE_STARTUP_TEST
 439 extern int trace_selftest_startup_function(struct tracer *trace,
 440                                            struct trace_array *tr);
 441 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 442                                                  struct trace_array *tr);
 443 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 444                                           struct trace_array *tr);
 445 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 446                                              struct trace_array *tr);
 447 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 448                                                  struct trace_array *tr);
 449 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 450                                          struct trace_array *tr);
 451 extern int trace_selftest_startup_nop(struct tracer *trace,
 452                                          struct trace_array *tr);
 453 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 454                                                struct trace_array *tr);
 455 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 456                                                struct trace_array *tr);
 457 extern int trace_selftest_startup_branch(struct tracer *trace,
 458                                          struct trace_array *tr);
 459 extern int trace_selftest_startup_ksym(struct tracer *trace,
 460                                          struct trace_array *tr);
 461 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 462
 463 extern void *head_page(struct trace_array_cpu *data);
 464 extern unsigned long long ns2usecs(cycle_t nsec);
 465 extern int
 466 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 467 extern int
 468 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 469 extern int
 470 trace_array_vprintk(struct trace_array *tr,
 471                     unsigned long ip, const char *fmt, va_list args);
 472 int trace_array_printk(struct trace_array *tr,
 473                        unsigned long ip, const char *fmt, ...);
 474
 475 extern unsigned long trace_flags;
 476
 477 extern int trace_clock_id;
 478
 479 /* Standard output formatting function used for function return traces */
 480 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 481
 482 /* Flag options */
 483 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
 484 #define TRACE_GRAPH_PRINT_CPU           0x2
 485 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
 486 #define TRACE_GRAPH_PRINT_PROC          0x8
 487 #define TRACE_GRAPH_PRINT_DURATION      0x10
 488 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
 489
 490 extern enum print_line_t
 491 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
 492 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
 493 extern enum print_line_t
 494 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 495 extern void graph_trace_open(struct trace_iterator *iter);
 496 extern void graph_trace_close(struct trace_iterator *iter);
 497 extern int __trace_graph_entry(struct trace_array *tr,
 498                                struct ftrace_graph_ent *trace,
 499                                unsigned long flags, int pc);
 500 extern void __trace_graph_return(struct trace_array *tr,
 501                                  struct ftrace_graph_ret *trace,
 502                                  unsigned long flags, int pc);
 503
 504
 505 #ifdef CONFIG_DYNAMIC_FTRACE
 506 /* TODO: make this variable */
 507 #define FTRACE_GRAPH_MAX_FUNCS          32
 508 extern int ftrace_graph_filter_enabled;
 509 extern int ftrace_graph_count;
 510 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 511
 512 static inline int ftrace_graph_addr(unsigned long addr)
 513 {
 514         int i;
 515
 516         if (!ftrace_graph_filter_enabled)
 517                 return 1;
 518
 519         for (i = 0; i < ftrace_graph_count; i++) {
 520                 if (addr == ftrace_graph_funcs[i])
 521                         return 1;
 522         }
 523
 524         return 0;
 525 }
 526 #else
 527 static inline int ftrace_graph_addr(unsigned long addr)
 528 {
 529         return 1;
 530 }
 531 #endif /* CONFIG_DYNAMIC_FTRACE */
 532 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 533 static inline enum print_line_t
 534 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 535 {
 536         return TRACE_TYPE_UNHANDLED;
 537 }
 538 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 539
 540 extern struct list_head ftrace_pids;
 541
 542 #ifdef CONFIG_FUNCTION_TRACER
 543 static inline int ftrace_trace_task(struct task_struct *task)
 544 {
 545         if (list_empty(&ftrace_pids))
 546                 return 1;
 547
 548         return test_tsk_trace_trace(task);
 549 }
 550 #else
 551 static inline int ftrace_trace_task(struct task_struct *task)
 552 {
 553         return 1;
 554 }
 555 #endif
 556
 557 /*
 558  * struct trace_parser - servers for reading the user input separated by spaces
 559  * @cont: set if the input is not complete - no final space char was found
 560  * @buffer: holds the parsed user input
 561  * @idx: user input length
 562  * @size: buffer size
 563  */
 564 struct trace_parser {
 565         bool            cont;
 566         char            *buffer;
 567         unsigned        idx;
 568         unsigned        size;
 569 };
 570
 571 static inline bool trace_parser_loaded(struct trace_parser *parser)
 572 {
 573         return (parser->idx != 0);
 574 }
 575
 576 static inline bool trace_parser_cont(struct trace_parser *parser)
 577 {
 578         return parser->cont;
 579 }
 580
 581 static inline void trace_parser_clear(struct trace_parser *parser)
 582 {
 583         parser->cont = false;
 584         parser->idx = 0;
 585 }
 586
 587 extern int trace_parser_get_init(struct trace_parser *parser, int size);
 588 extern void trace_parser_put(struct trace_parser *parser);
 589 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 590         size_t cnt, loff_t *ppos);
 591
 592 /*
 593  * trace_iterator_flags is an enumeration that defines bit
 594  * positions into trace_flags that controls the output.
 595  *
 596  * NOTE: These bits must match the trace_options array in
 597  *       trace.c.
 598  */
 599 enum trace_iterator_flags {
 600         TRACE_ITER_PRINT_PARENT         = 0x01,
 601         TRACE_ITER_SYM_OFFSET           = 0x02,
 602         TRACE_ITER_SYM_ADDR             = 0x04,
 603         TRACE_ITER_VERBOSE              = 0x08,
 604         TRACE_ITER_RAW                  = 0x10,
 605         TRACE_ITER_HEX                  = 0x20,
 606         TRACE_ITER_BIN                  = 0x40,
 607         TRACE_ITER_BLOCK                = 0x80,
 608         TRACE_ITER_STACKTRACE           = 0x100,
 609         TRACE_ITER_PRINTK               = 0x200,
 610         TRACE_ITER_PREEMPTONLY          = 0x400,
 611         TRACE_ITER_BRANCH               = 0x800,
 612         TRACE_ITER_ANNOTATE             = 0x1000,
 613         TRACE_ITER_USERSTACKTRACE       = 0x2000,
 614         TRACE_ITER_SYM_USEROBJ          = 0x4000,
 615         TRACE_ITER_PRINTK_MSGONLY       = 0x8000,
 616         TRACE_ITER_CONTEXT_INFO         = 0x10000, /* Print pid/cpu/time */
 617         TRACE_ITER_LATENCY_FMT          = 0x20000,
 618         TRACE_ITER_SLEEP_TIME           = 0x40000,
 619         TRACE_ITER_GRAPH_TIME           = 0x80000,
 620 };
 621
 622 /*
 623  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 624  * control the output of kernel symbols.
 625  */
 626 #define TRACE_ITER_SYM_MASK \
 627         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 628
 629 extern struct tracer nop_trace;
 630
 631 /**
 632  * ftrace_preempt_disable - disable preemption scheduler safe
 633  *
 634  * When tracing can happen inside the scheduler, there exists
 635  * cases that the tracing might happen before the need_resched
 636  * flag is checked. If this happens and the tracer calls
 637  * preempt_enable (after a disable), a schedule might take place
 638  * causing an infinite recursion.
 639  *
 640  * To prevent this, we read the need_resched flag before
 641  * disabling preemption. When we want to enable preemption we
 642  * check the flag, if it is set, then we call preempt_enable_no_resched.
 643  * Otherwise, we call preempt_enable.
 644  *
 645  * The rational for doing the above is that if need_resched is set
 646  * and we have yet to reschedule, we are either in an atomic location
 647  * (where we do not need to check for scheduling) or we are inside
 648  * the scheduler and do not want to resched.
 649  */
 650 static inline int ftrace_preempt_disable(void)
 651 {
 652         int resched;
 653
 654         resched = need_resched();
 655         preempt_disable_notrace();
 656
 657         return resched;
 658 }
 659
 660 /**
 661  * ftrace_preempt_enable - enable preemption scheduler safe
 662  * @resched: the return value from ftrace_preempt_disable
 663  *
 664  * This is a scheduler safe way to enable preemption and not miss
 665  * any preemption checks. The disabled saved the state of preemption.
 666  * If resched is set, then we are either inside an atomic or
 667  * are inside the scheduler (we would have already scheduled
 668  * otherwise). In this case, we do not want to call normal
 669  * preempt_enable, but preempt_enable_no_resched instead.
 670  */
 671 static inline void ftrace_preempt_enable(int resched)
 672 {
 673         if (resched)
 674                 preempt_enable_no_resched_notrace();
 675         else
 676                 preempt_enable_notrace();
 677 }
 678
 679 #ifdef CONFIG_BRANCH_TRACER
 680 extern int enable_branch_tracing(struct trace_array *tr);
 681 extern void disable_branch_tracing(void);
 682 static inline int trace_branch_enable(struct trace_array *tr)
 683 {
 684         if (trace_flags & TRACE_ITER_BRANCH)
 685                 return enable_branch_tracing(tr);
 686         return 0;
 687 }
 688 static inline void trace_branch_disable(void)
 689 {
 690         /* due to races, always disable */
 691         disable_branch_tracing();
 692 }
 693 #else
 694 static inline int trace_branch_enable(struct trace_array *tr)
 695 {
 696         return 0;
 697 }
 698 static inline void trace_branch_disable(void)
 699 {
 700 }
 701 #endif /* CONFIG_BRANCH_TRACER */
 702
 703 /* set ring buffers to default size if not already done so */
 704 int tracing_update_buffers(void);
 705
 706 /* trace event type bit fields, not numeric */
 707 enum {
 708         TRACE_EVENT_TYPE_PRINTF         = 1,
 709         TRACE_EVENT_TYPE_RAW            = 2,
 710 };
 711
 712 struct ftrace_event_field {
 713         struct list_head        link;
 714         char                    *name;
 715         char                    *type;
 716         int                     filter_type;
 717         int                     offset;
 718         int                     size;
 719         int                     is_signed;
 720 };
 721
 722 struct event_filter {
 723         int                     n_preds;
 724         struct filter_pred      **preds;
 725         char                    *filter_string;
 726 };
 727
 728 struct event_subsystem {
 729         struct list_head        list;
 730         const char              *name;
 731         struct dentry           *entry;
 732         struct event_filter     *filter;
 733         int                     nr_events;
 734 };
 735
 736 struct filter_pred;
 737 struct regex;
 738
 739 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 740                                  int val1, int val2);
 741
 742 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
 743
 744 enum regex_type {
 745         MATCH_FULL = 0,
 746         MATCH_FRONT_ONLY,
 747         MATCH_MIDDLE_ONLY,
 748         MATCH_END_ONLY,
 749 };
 750
 751 struct regex {
 752         char                    pattern[MAX_FILTER_STR_VAL];
 753         int                     len;
 754         int                     field_len;
 755         regex_match_func        match;
 756 };
 757
 758 struct filter_pred {
 759         filter_pred_fn_t        fn;
 760         u64                     val;
 761         struct regex            regex;
 762         char                    *field_name;
 763         int                     offset;
 764         int                     not;
 765         int                     op;
 766         int                     pop_n;
 767 };
 768
 769 extern enum regex_type
 770 filter_parse_regex(char *buff, int len, char **search, int *not);
 771 extern void print_event_filter(struct ftrace_event_call *call,
 772                                struct trace_seq *s);
 773 extern int apply_event_filter(struct ftrace_event_call *call,
 774                               char *filter_string);
 775 extern int apply_subsystem_event_filter(struct event_subsystem *system,
 776                                         char *filter_string);
 777 extern void print_subsystem_event_filter(struct event_subsystem *system,
 778                                          struct trace_seq *s);
 779 extern int filter_assign_type(const char *type);
 780
 781 struct list_head *
 782 trace_get_fields(struct ftrace_event_call *event_call);
 783
 784 static inline int
 785 filter_check_discard(struct ftrace_event_call *call, void *rec,
 786                      struct ring_buffer *buffer,
 787                      struct ring_buffer_event *event)
 788 {
 789         if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
 790             !filter_match_preds(call->filter, rec)) {
 791                 ring_buffer_discard_commit(buffer, event);
 792                 return 1;
 793         }
 794
 795         return 0;
 796 }
 797
 798 extern struct mutex event_mutex;
 799 extern struct list_head ftrace_events;
 800
 801 extern const char *__start___trace_bprintk_fmt[];
 802 extern const char *__stop___trace_bprintk_fmt[];
 803
 804 #undef FTRACE_ENTRY
 805 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)             \
 806         extern struct ftrace_event_call                                 \
 807         __attribute__((__aligned__(4))) event_##call;
 808 #undef FTRACE_ENTRY_DUP
 809 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)         \
 810         FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 811 #include "trace_entries.h"
 812
 813 #endif /* _LINUX_KERNEL_TRACE_H */