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