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