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
  15 #include <linux/trace_seq.h>
  16 #include <linux/ftrace_event.h>
  17
  18 #ifdef CONFIG_KSYM_TRACER
  19 #include <asm/hw_breakpoint.h>
  20 #endif
  21
  22 enum trace_type {
  23         __TRACE_FIRST_TYPE = 0,
  24
  25         TRACE_FN,
  26         TRACE_CTX,
  27         TRACE_WAKE,
  28         TRACE_STACK,
  29         TRACE_PRINT,
  30         TRACE_BPRINT,
  31         TRACE_SPECIAL,
  32         TRACE_MMIO_RW,
  33         TRACE_MMIO_MAP,
  34         TRACE_BRANCH,
  35         TRACE_BOOT_CALL,
  36         TRACE_BOOT_RET,
  37         TRACE_GRAPH_RET,
  38         TRACE_GRAPH_ENT,
  39         TRACE_USER_STACK,
  40         TRACE_HW_BRANCHES,
  41         TRACE_KMEM_ALLOC,
  42         TRACE_KMEM_FREE,
  43         TRACE_BLK,
  44         TRACE_KSYM,
  45
  46         __TRACE_LAST_TYPE,
  47 };
  48
  49 enum kmemtrace_type_id {
  50         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
  51         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
  52         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
  53 };
  54
  55 extern struct tracer boot_tracer;
  56
  57 #undef __field
  58 #define __field(type, item)             type    item;
  59
  60 #undef __field_struct
  61 #define __field_struct(type, item)      __field(type, item)
  62
  63 #undef __field_desc
  64 #define __field_desc(type, container, item)
  65
  66 #undef __array
  67 #define __array(type, item, size)       type    item[size];
  68
  69 #undef __array_desc
  70 #define __array_desc(type, container, item, size)
  71
  72 #undef __dynamic_array
  73 #define __dynamic_array(type, item)     type    item[];
  74
  75 #undef F_STRUCT
  76 #define F_STRUCT(args...)               args
  77
  78 #undef FTRACE_ENTRY
  79 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)     \
  80         struct struct_name {                                    \
  81                 struct trace_entry      ent;                    \
  82                 tstruct                                         \
  83         }
  84
  85 #undef TP_ARGS
  86 #define TP_ARGS(args...)        args
  87
  88 #undef FTRACE_ENTRY_DUP
  89 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
  90
  91 #include "trace_entries.h"
  92
  93 /*
  94  * syscalls are special, and need special handling, this is why
  95  * they are not included in trace_entries.h
  96  */
  97 struct syscall_trace_enter {
  98         struct trace_entry      ent;
  99         int                     nr;
 100         unsigned long           args[];
 101 };
 102
 103 struct syscall_trace_exit {
 104         struct trace_entry      ent;
 105         int                     nr;
 106         unsigned long           ret;
 107 };
 108
 109 /*
 110  * trace_flag_type is an enumeration that holds different
 111  * states when a trace occurs. These are:
 112  *  IRQS_OFF            - interrupts were disabled
 113  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 114  *  NEED_RESCHED        - reschedule is requested
 115  *  HARDIRQ             - inside an interrupt handler
 116  *  SOFTIRQ             - inside a softirq handler
 117  */
 118 enum trace_flag_type {
 119         TRACE_FLAG_IRQS_OFF             = 0x01,
 120         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 121         TRACE_FLAG_NEED_RESCHED         = 0x04,
 122         TRACE_FLAG_HARDIRQ              = 0x08,
 123         TRACE_FLAG_SOFTIRQ              = 0x10,
 124 };
 125
 126 #define TRACE_BUF_SIZE          1024
 127
 128 /*
 129  * The CPU trace array - it consists of thousands of trace entries
 130  * plus some other descriptor data: (for example which task started
 131  * the trace, etc.)
 132  */
 133 struct trace_array_cpu {
 134         atomic_t                disabled;
 135         void                    *buffer_page;   /* ring buffer spare */
 136
 137         unsigned long           saved_latency;
 138         unsigned long           critical_start;
 139         unsigned long           critical_end;
 140         unsigned long           critical_sequence;
 141         unsigned long           nice;
 142         unsigned long           policy;
 143         unsigned long           rt_priority;
 144         unsigned long           skipped_entries;
 145         cycle_t                 preempt_timestamp;
 146         pid_t                   pid;
 147         uid_t                   uid;
 148         char                    comm[TASK_COMM_LEN];
 149 };
 150
 151 /*
 152  * The trace array - an array of per-CPU trace arrays. This is the
 153  * highest level data structure that individual tracers deal with.
 154  * They have on/off state as well:
 155  */
 156 struct trace_array {
 157         struct ring_buffer      *buffer;
 158         unsigned long           entries;
 159         int                     cpu;
 160         cycle_t                 time_start;
 161         struct task_struct      *waiter;
 162         struct trace_array_cpu  *data[NR_CPUS];
 163 };
 164
 165 #define FTRACE_CMP_TYPE(var, type) \
 166         __builtin_types_compatible_p(typeof(var), type *)
 167
 168 #undef IF_ASSIGN
 169 #define IF_ASSIGN(var, entry, etype, id)                \
 170         if (FTRACE_CMP_TYPE(var, etype)) {              \
 171                 var = (typeof(var))(entry);             \
 172                 WARN_ON(id && (entry)->type != id);     \
 173                 break;                                  \
 174         }
 175
 176 /* Will cause compile errors if type is not found. */
 177 extern void __ftrace_bad_type(void);
 178
 179 /*
 180  * The trace_assign_type is a verifier that the entry type is
 181  * the same as the type being assigned. To add new types simply
 182  * add a line with the following format:
 183  *
 184  * IF_ASSIGN(var, ent, type, id);
 185  *
 186  *  Where "type" is the trace type that includes the trace_entry
 187  *  as the "ent" item. And "id" is the trace identifier that is
 188  *  used in the trace_type enum.
 189  *
 190  *  If the type can have more than one id, then use zero.
 191  */
 192 #define trace_assign_type(var, ent)                                     \
 193         do {                                                            \
 194                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 195                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 196                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 197                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 198                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 199                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 200                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 201                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 202                           TRACE_MMIO_RW);                               \
 203                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 204                           TRACE_MMIO_MAP);                              \
 205                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 206                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 207                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 208                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 209                           TRACE_GRAPH_ENT);             \
 210                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 211                           TRACE_GRAPH_RET);             \
 212                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 213                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 214                           TRACE_KMEM_ALLOC);    \
 215                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 216                           TRACE_KMEM_FREE);     \
 217                 IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\
 218                 __ftrace_bad_type();                                    \
 219         } while (0)
 220
 221 /*
 222  * An option specific to a tracer. This is a boolean value.
 223  * The bit is the bit index that sets its value on the
 224  * flags value in struct tracer_flags.
 225  */
 226 struct tracer_opt {
 227         const char      *name; /* Will appear on the trace_options file */
 228         u32             bit; /* Mask assigned in val field in tracer_flags */
 229 };
 230
 231 /*
 232  * The set of specific options for a tracer. Your tracer
 233  * have to set the initial value of the flags val.
 234  */
 235 struct tracer_flags {
 236         u32                     val;
 237         struct tracer_opt       *opts;
 238 };
 239
 240 /* Makes more easy to define a tracer opt */
 241 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 242
 243
 244 /**
 245  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 246  * @name: the name chosen to select it on the available_tracers file
 247  * @init: called when one switches to this tracer (echo name > current_tracer)
 248  * @reset: called when one switches to another tracer
 249  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 250  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 251  * @open: called when the trace file is opened
 252  * @pipe_open: called when the trace_pipe file is opened
 253  * @wait_pipe: override how the user waits for traces on trace_pipe
 254  * @close: called when the trace file is released
 255  * @read: override the default read callback on trace_pipe
 256  * @splice_read: override the default splice_read callback on trace_pipe
 257  * @selftest: selftest to run on boot (see trace_selftest.c)
 258  * @print_headers: override the first lines that describe your columns
 259  * @print_line: callback that prints a trace
 260  * @set_flag: signals one of your private flags changed (trace_options file)
 261  * @flags: your private flags
 262  */
 263 struct tracer {
 264         const char              *name;
 265         int                     (*init)(struct trace_array *tr);
 266         void                    (*reset)(struct trace_array *tr);
 267         void                    (*start)(struct trace_array *tr);
 268         void                    (*stop)(struct trace_array *tr);
 269         void                    (*open)(struct trace_iterator *iter);
 270         void                    (*pipe_open)(struct trace_iterator *iter);
 271         void                    (*wait_pipe)(struct trace_iterator *iter);
 272         void                    (*close)(struct trace_iterator *iter);
 273         ssize_t                 (*read)(struct trace_iterator *iter,
 274                                         struct file *filp, char __user *ubuf,
 275                                         size_t cnt, loff_t *ppos);
 276         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 277                                                struct file *filp,
 278                                                loff_t *ppos,
 279                                                struct pipe_inode_info *pipe,
 280                                                size_t len,
 281                                                unsigned int flags);
 282 #ifdef CONFIG_FTRACE_STARTUP_TEST
 283         int                     (*selftest)(struct tracer *trace,
 284                                             struct trace_array *tr);
 285 #endif
 286         void                    (*print_header)(struct seq_file *m);
 287         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 288         /* If you handled the flag setting, return 0 */
 289         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 290         struct tracer           *next;
 291         int                     print_max;
 292         struct tracer_flags     *flags;
 293 };
 294
 295
 296 #define TRACE_PIPE_ALL_CPU      -1
 297
 298 int tracer_init(struct tracer *t, struct trace_array *tr);
 299 int tracing_is_enabled(void);
 300 void trace_wake_up(void);
 301 void tracing_reset(struct trace_array *tr, int cpu);
 302 void tracing_reset_online_cpus(struct trace_array *tr);
 303 void tracing_reset_current(int cpu);
 304 void tracing_reset_current_online_cpus(void);
 305 int tracing_open_generic(struct inode *inode, struct file *filp);
 306 struct dentry *trace_create_file(const char *name,
 307                                  mode_t mode,
 308                                  struct dentry *parent,
 309                                  void *data,
 310                                  const struct file_operations *fops);
 311
 312 struct dentry *tracing_init_dentry(void);
 313 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 314
 315 struct ring_buffer_event;
 316
 317 struct ring_buffer_event *
 318 trace_buffer_lock_reserve(struct ring_buffer *buffer,
 319                           int type,
 320                           unsigned long len,
 321                           unsigned long flags,
 322                           int pc);
 323 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
 324                                 struct ring_buffer_event *event,
 325                                 unsigned long flags, int pc);
 326
 327 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 328                                                 struct trace_array_cpu *data);
 329
 330 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 331                                           int *ent_cpu, u64 *ent_ts);
 332
 333 void default_wait_pipe(struct trace_iterator *iter);
 334 void poll_wait_pipe(struct trace_iterator *iter);
 335
 336 void ftrace(struct trace_array *tr,
 337                             struct trace_array_cpu *data,
 338                             unsigned long ip,
 339                             unsigned long parent_ip,
 340                             unsigned long flags, int pc);
 341 void tracing_sched_switch_trace(struct trace_array *tr,
 342                                 struct task_struct *prev,
 343                                 struct task_struct *next,
 344                                 unsigned long flags, int pc);
 345
 346 void tracing_sched_wakeup_trace(struct trace_array *tr,
 347                                 struct task_struct *wakee,
 348                                 struct task_struct *cur,
 349                                 unsigned long flags, int pc);
 350 void trace_special(struct trace_array *tr,
 351                    struct trace_array_cpu *data,
 352                    unsigned long arg1,
 353                    unsigned long arg2,
 354                    unsigned long arg3, int pc);
 355 void trace_function(struct trace_array *tr,
 356                     unsigned long ip,
 357                     unsigned long parent_ip,
 358                     unsigned long flags, int pc);
 359
 360 void trace_graph_return(struct ftrace_graph_ret *trace);
 361 int trace_graph_entry(struct ftrace_graph_ent *trace);
 362 void set_graph_array(struct trace_array *tr);
 363
 364 void tracing_start_cmdline_record(void);
 365 void tracing_stop_cmdline_record(void);
 366 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 367 void tracing_stop_sched_switch_record(void);
 368 void tracing_start_sched_switch_record(void);
 369 int register_tracer(struct tracer *type);
 370 void unregister_tracer(struct tracer *type);
 371 int is_tracing_stopped(void);
 372
 373 #define KSYM_SELFTEST_ENTRY "ksym_selftest_dummy"
 374 extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr);
 375
 376 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 377
 378 #ifdef CONFIG_TRACER_MAX_TRACE
 379 extern unsigned long tracing_max_latency;
 380 extern unsigned long tracing_thresh;
 381
 382 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 383 void update_max_tr_single(struct trace_array *tr,
 384                           struct task_struct *tsk, int cpu);
 385 #endif /* CONFIG_TRACER_MAX_TRACE */
 386
 387 #ifdef CONFIG_STACKTRACE
 388 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 389                         int skip, int pc);
 390
 391 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 392                             int pc);
 393
 394 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 395                    int pc);
 396 #else
 397 static inline void ftrace_trace_stack(struct trace_array *tr,
 398                                       unsigned long flags, int skip, int pc)
 399 {
 400 }
 401
 402 static inline void ftrace_trace_userstack(struct trace_array *tr,
 403                                           unsigned long flags, int pc)
 404 {
 405 }
 406
 407 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 408                                  int skip, int pc)
 409 {
 410 }
 411 #endif /* CONFIG_STACKTRACE */
 412
 413 extern cycle_t ftrace_now(int cpu);
 414
 415 extern void trace_find_cmdline(int pid, char comm[]);
 416
 417 #ifdef CONFIG_DYNAMIC_FTRACE
 418 extern unsigned long ftrace_update_tot_cnt;
 419 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 420 extern int DYN_FTRACE_TEST_NAME(void);
 421 #endif
 422
 423 extern int ring_buffer_expanded;
 424 extern bool tracing_selftest_disabled;
 425 DECLARE_PER_CPU(local_t, ftrace_cpu_disabled);
 426
 427 #ifdef CONFIG_FTRACE_STARTUP_TEST
 428 extern int trace_selftest_startup_function(struct tracer *trace,
 429                                            struct trace_array *tr);
 430 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 431                                                  struct trace_array *tr);
 432 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 433                                           struct trace_array *tr);
 434 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 435                                              struct trace_array *tr);
 436 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 437                                                  struct trace_array *tr);
 438 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 439                                          struct trace_array *tr);
 440 extern int trace_selftest_startup_nop(struct tracer *trace,
 441                                          struct trace_array *tr);
 442 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 443                                                struct trace_array *tr);
 444 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 445                                                struct trace_array *tr);
 446 extern int trace_selftest_startup_branch(struct tracer *trace,
 447                                          struct trace_array *tr);
 448 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
 449                                               struct trace_array *tr);
 450 extern int trace_selftest_startup_ksym(struct tracer *trace,
 451                                          struct trace_array *tr);
 452 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 453
 454 extern void *head_page(struct trace_array_cpu *data);
 455 extern unsigned long long ns2usecs(cycle_t nsec);
 456 extern int
 457 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 458 extern int
 459 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 460 extern int
 461 trace_array_vprintk(struct trace_array *tr,
 462                     unsigned long ip, const char *fmt, va_list args);
 463 int trace_array_printk(struct trace_array *tr,
 464                        unsigned long ip, const char *fmt, ...);
 465
 466 extern unsigned long trace_flags;
 467
 468 extern int trace_clock_id;
 469
 470 /* Standard output formatting function used for function return traces */
 471 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 472 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 473 extern enum print_line_t
 474 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 475
 476 #ifdef CONFIG_DYNAMIC_FTRACE
 477 /* TODO: make this variable */
 478 #define FTRACE_GRAPH_MAX_FUNCS          32
 479 extern int ftrace_graph_count;
 480 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 481
 482 static inline int ftrace_graph_addr(unsigned long addr)
 483 {
 484         int i;
 485
 486         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 487                 return 1;
 488
 489         for (i = 0; i < ftrace_graph_count; i++) {
 490                 if (addr == ftrace_graph_funcs[i])
 491                         return 1;
 492         }
 493
 494         return 0;
 495 }
 496 #else
 497 static inline int ftrace_graph_addr(unsigned long addr)
 498 {
 499         return 1;
 500 }
 501 #endif /* CONFIG_DYNAMIC_FTRACE */
 502 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 503 static inline enum print_line_t
 504 print_graph_function(struct trace_iterator *iter)
 505 {
 506         return TRACE_TYPE_UNHANDLED;
 507 }
 508 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 509
 510 extern struct list_head ftrace_pids;
 511
 512 #ifdef CONFIG_FUNCTION_TRACER
 513 static inline int ftrace_trace_task(struct task_struct *task)
 514 {
 515         if (list_empty(&ftrace_pids))
 516                 return 1;
 517
 518         return test_tsk_trace_trace(task);
 519 }
 520 #else
 521 static inline int ftrace_trace_task(struct task_struct *task)
 522 {
 523         return 1;
 524 }
 525 #endif
 526
 527 /*
 528  * struct trace_parser - servers for reading the user input separated by spaces
 529  * @cont: set if the input is not complete - no final space char was found
 530  * @buffer: holds the parsed user input
 531  * @idx: user input lenght
 532  * @size: buffer size
 533  */
 534 struct trace_parser {
 535         bool            cont;
 536         char            *buffer;
 537         unsigned        idx;
 538         unsigned        size;
 539 };
 540
 541 static inline bool trace_parser_loaded(struct trace_parser *parser)
 542 {
 543         return (parser->idx != 0);
 544 }
 545
 546 static inline bool trace_parser_cont(struct trace_parser *parser)
 547 {
 548         return parser->cont;
 549 }
 550
 551 static inline void trace_parser_clear(struct trace_parser *parser)
 552 {
 553         parser->cont = false;
 554         parser->idx = 0;
 555 }
 556
 557 extern int trace_parser_get_init(struct trace_parser *parser, int size);
 558 extern void trace_parser_put(struct trace_parser *parser);
 559 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 560         size_t cnt, loff_t *ppos);
 561
 562 /*
 563  * trace_iterator_flags is an enumeration that defines bit
 564  * positions into trace_flags that controls the output.
 565  *
 566  * NOTE: These bits must match the trace_options array in
 567  *       trace.c.
 568  */
 569 enum trace_iterator_flags {
 570         TRACE_ITER_PRINT_PARENT         = 0x01,
 571         TRACE_ITER_SYM_OFFSET           = 0x02,
 572         TRACE_ITER_SYM_ADDR             = 0x04,
 573         TRACE_ITER_VERBOSE              = 0x08,
 574         TRACE_ITER_RAW                  = 0x10,
 575         TRACE_ITER_HEX                  = 0x20,
 576         TRACE_ITER_BIN                  = 0x40,
 577         TRACE_ITER_BLOCK                = 0x80,
 578         TRACE_ITER_STACKTRACE           = 0x100,
 579         TRACE_ITER_SCHED_TREE           = 0x200,
 580         TRACE_ITER_PRINTK               = 0x400,
 581         TRACE_ITER_PREEMPTONLY          = 0x800,
 582         TRACE_ITER_BRANCH               = 0x1000,
 583         TRACE_ITER_ANNOTATE             = 0x2000,
 584         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 585         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 586         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 587         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 588         TRACE_ITER_LATENCY_FMT          = 0x40000,
 589         TRACE_ITER_SLEEP_TIME           = 0x80000,
 590         TRACE_ITER_GRAPH_TIME           = 0x100000,
 591 };
 592
 593 /*
 594  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 595  * control the output of kernel symbols.
 596  */
 597 #define TRACE_ITER_SYM_MASK \
 598         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 599
 600 extern struct tracer nop_trace;
 601
 602 /**
 603  * ftrace_preempt_disable - disable preemption scheduler safe
 604  *
 605  * When tracing can happen inside the scheduler, there exists
 606  * cases that the tracing might happen before the need_resched
 607  * flag is checked. If this happens and the tracer calls
 608  * preempt_enable (after a disable), a schedule might take place
 609  * causing an infinite recursion.
 610  *
 611  * To prevent this, we read the need_resched flag before
 612  * disabling preemption. When we want to enable preemption we
 613  * check the flag, if it is set, then we call preempt_enable_no_resched.
 614  * Otherwise, we call preempt_enable.
 615  *
 616  * The rational for doing the above is that if need_resched is set
 617  * and we have yet to reschedule, we are either in an atomic location
 618  * (where we do not need to check for scheduling) or we are inside
 619  * the scheduler and do not want to resched.
 620  */
 621 static inline int ftrace_preempt_disable(void)
 622 {
 623         int resched;
 624
 625         resched = need_resched();
 626         preempt_disable_notrace();
 627
 628         return resched;
 629 }
 630
 631 /**
 632  * ftrace_preempt_enable - enable preemption scheduler safe
 633  * @resched: the return value from ftrace_preempt_disable
 634  *
 635  * This is a scheduler safe way to enable preemption and not miss
 636  * any preemption checks. The disabled saved the state of preemption.
 637  * If resched is set, then we are either inside an atomic or
 638  * are inside the scheduler (we would have already scheduled
 639  * otherwise). In this case, we do not want to call normal
 640  * preempt_enable, but preempt_enable_no_resched instead.
 641  */
 642 static inline void ftrace_preempt_enable(int resched)
 643 {
 644         if (resched)
 645                 preempt_enable_no_resched_notrace();
 646         else
 647                 preempt_enable_notrace();
 648 }
 649
 650 #ifdef CONFIG_BRANCH_TRACER
 651 extern int enable_branch_tracing(struct trace_array *tr);
 652 extern void disable_branch_tracing(void);
 653 static inline int trace_branch_enable(struct trace_array *tr)
 654 {
 655         if (trace_flags & TRACE_ITER_BRANCH)
 656                 return enable_branch_tracing(tr);
 657         return 0;
 658 }
 659 static inline void trace_branch_disable(void)
 660 {
 661         /* due to races, always disable */
 662         disable_branch_tracing();
 663 }
 664 #else
 665 static inline int trace_branch_enable(struct trace_array *tr)
 666 {
 667         return 0;
 668 }
 669 static inline void trace_branch_disable(void)
 670 {
 671 }
 672 #endif /* CONFIG_BRANCH_TRACER */
 673
 674 /* set ring buffers to default size if not already done so */
 675 int tracing_update_buffers(void);
 676
 677 /* trace event type bit fields, not numeric */
 678 enum {
 679         TRACE_EVENT_TYPE_PRINTF         = 1,
 680         TRACE_EVENT_TYPE_RAW            = 2,
 681 };
 682
 683 struct ftrace_event_field {
 684         struct list_head        link;
 685         char                    *name;
 686         char                    *type;
 687         int                     filter_type;
 688         int                     offset;
 689         int                     size;
 690         int                     is_signed;
 691 };
 692
 693 struct event_filter {
 694         int                     n_preds;
 695         struct filter_pred      **preds;
 696         char                    *filter_string;
 697 };
 698
 699 struct event_subsystem {
 700         struct list_head        list;
 701         const char              *name;
 702         struct dentry           *entry;
 703         struct event_filter     *filter;
 704         int                     nr_events;
 705 };
 706
 707 struct filter_pred;
 708 struct regex;
 709
 710 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 711                                  int val1, int val2);
 712
 713 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
 714
 715 enum regex_type {
 716         MATCH_FULL = 0,
 717         MATCH_FRONT_ONLY,
 718         MATCH_MIDDLE_ONLY,
 719         MATCH_END_ONLY,
 720 };
 721
 722 struct regex {
 723         char                    pattern[MAX_FILTER_STR_VAL];
 724         int                     len;
 725         int                     field_len;
 726         regex_match_func        match;
 727 };
 728
 729 struct filter_pred {
 730         filter_pred_fn_t        fn;
 731         u64                     val;
 732         struct regex            regex;
 733         char                    *field_name;
 734         int                     offset;
 735         int                     not;
 736         int                     op;
 737         int                     pop_n;
 738 };
 739
 740 extern enum regex_type
 741 filter_parse_regex(char *buff, int len, char **search, int *not);
 742 extern void print_event_filter(struct ftrace_event_call *call,
 743                                struct trace_seq *s);
 744 extern int apply_event_filter(struct ftrace_event_call *call,
 745                               char *filter_string);
 746 extern int apply_subsystem_event_filter(struct event_subsystem *system,
 747                                         char *filter_string);
 748 extern void print_subsystem_event_filter(struct event_subsystem *system,
 749                                          struct trace_seq *s);
 750 extern int filter_assign_type(const char *type);
 751
 752 static inline int
 753 filter_check_discard(struct ftrace_event_call *call, void *rec,
 754                      struct ring_buffer *buffer,
 755                      struct ring_buffer_event *event)
 756 {
 757         if (unlikely(call->filter_active) &&
 758             !filter_match_preds(call->filter, rec)) {
 759                 ring_buffer_discard_commit(buffer, event);
 760                 return 1;
 761         }
 762
 763         return 0;
 764 }
 765
 766 extern struct mutex event_mutex;
 767 extern struct list_head ftrace_events;
 768
 769 extern const char *__start___trace_bprintk_fmt[];
 770 extern const char *__stop___trace_bprintk_fmt[];
 771
 772 #undef FTRACE_ENTRY
 773 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)             \
 774         extern struct ftrace_event_call event_##call;
 775 #undef FTRACE_ENTRY_DUP
 776 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)         \
 777         FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 778 #include "trace_entries.h"
 779
 780 #endif /* _LINUX_KERNEL_TRACE_H */