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