kernel/trace/trace.h

   1 #ifndef _LINUX_KERNEL_TRACE_H
   2 #define _LINUX_KERNEL_TRACE_H
   3
   4 #include <linux/fs.h>
   5 #include <asm/atomic.h>
   6 #include <linux/sched.h>
   7 #include <linux/clocksource.h>
   8 #include <linux/ring_buffer.h>
   9 #include <linux/mmiotrace.h>
  10 #include <linux/tracepoint.h>
  11 #include <linux/ftrace.h>
  12 #include <trace/boot.h>
  13 #include <linux/kmemtrace.h>
  14 #include <linux/hw_breakpoint.h>
  15
  16 #include <linux/trace_seq.h>
  17 #include <linux/ftrace_event.h>
  18
  19 enum trace_type {
  20         __TRACE_FIRST_TYPE = 0,
  21
  22         TRACE_FN,
  23         TRACE_CTX,
  24         TRACE_WAKE,
  25         TRACE_STACK,
  26         TRACE_PRINT,
  27         TRACE_BPRINT,
  28         TRACE_SPECIAL,
  29         TRACE_MMIO_RW,
  30         TRACE_MMIO_MAP,
  31         TRACE_BRANCH,
  32         TRACE_BOOT_CALL,
  33         TRACE_BOOT_RET,
  34         TRACE_GRAPH_RET,
  35         TRACE_GRAPH_ENT,
  36         TRACE_USER_STACK,
  37         TRACE_KMEM_ALLOC,
  38         TRACE_KMEM_FREE,
  39         TRACE_BLK,
  40         TRACE_KSYM,
  41
  42         __TRACE_LAST_TYPE,
  43 };
  44
  45 enum kmemtrace_type_id {
  46         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
  47         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
  48         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
  49 };
  50
  51 extern struct tracer boot_tracer;
  52
  53 #undef __field
  54 #define __field(type, item)             type    item;
  55
  56 #undef __field_struct
  57 #define __field_struct(type, item)      __field(type, item)
  58
  59 #undef __field_desc
  60 #define __field_desc(type, container, item)
  61
  62 #undef __array
  63 #define __array(type, item, size)       type    item[size];
  64
  65 #undef __array_desc
  66 #define __array_desc(type, container, item, size)
  67
  68 #undef __dynamic_array
  69 #define __dynamic_array(type, item)     type    item[];
  70
  71 #undef F_STRUCT
  72 #define F_STRUCT(args...)               args
  73
  74 #undef FTRACE_ENTRY
  75 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)     \
  76         struct struct_name {                                    \
  77                 struct trace_entry      ent;                    \
  78                 tstruct                                         \
  79         }
  80
  81 #undef TP_ARGS
  82 #define TP_ARGS(args...)        args
  83
  84 #undef FTRACE_ENTRY_DUP
  85 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
  86
  87 #include "trace_entries.h"
  88
  89 /*
  90  * syscalls are special, and need special handling, this is why
  91  * they are not included in trace_entries.h
  92  */
  93 struct syscall_trace_enter {
  94         struct trace_entry      ent;
  95         int                     nr;
  96         unsigned long           args[];
  97 };
  98
  99 struct syscall_trace_exit {
 100         struct trace_entry      ent;
 101         int                     nr;
 102         long                    ret;
 103 };
 104
 105 struct kprobe_trace_entry_head {
 106         struct trace_entry      ent;
 107         unsigned long           ip;
 108 };
 109
 110 struct kretprobe_trace_entry_head {
 111         struct trace_entry      ent;
 112         unsigned long           func;
 113         unsigned long           ret_ip;
 114 };
 115
 116 /*
 117  * trace_flag_type is an enumeration that holds different
 118  * states when a trace occurs. These are:
 119  *  IRQS_OFF            - interrupts were disabled
 120  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 121  *  NEED_RESCHED        - reschedule is requested
 122  *  HARDIRQ             - inside an interrupt handler
 123  *  SOFTIRQ             - inside a softirq handler
 124  */
 125 enum trace_flag_type {
 126         TRACE_FLAG_IRQS_OFF             = 0x01,
 127         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 128         TRACE_FLAG_NEED_RESCHED         = 0x04,
 129         TRACE_FLAG_HARDIRQ              = 0x08,
 130         TRACE_FLAG_SOFTIRQ              = 0x10,
 131 };
 132
 133 #define TRACE_BUF_SIZE          1024
 134
 135 /*
 136  * The CPU trace array - it consists of thousands of trace entries
 137  * plus some other descriptor data: (for example which task started
 138  * the trace, etc.)
 139  */
 140 struct trace_array_cpu {
 141         atomic_t                disabled;
 142         void                    *buffer_page;   /* ring buffer spare */
 143
 144         unsigned long           saved_latency;
 145         unsigned long           critical_start;
 146         unsigned long           critical_end;
 147         unsigned long           critical_sequence;
 148         unsigned long           nice;
 149         unsigned long           policy;
 150         unsigned long           rt_priority;
 151         unsigned long           skipped_entries;
 152         cycle_t                 preempt_timestamp;
 153         pid_t                   pid;
 154         uid_t                   uid;
 155         char                    comm[TASK_COMM_LEN];
 156 };
 157
 158 /*
 159  * The trace array - an array of per-CPU trace arrays. This is the
 160  * highest level data structure that individual tracers deal with.
 161  * They have on/off state as well:
 162  */
 163 struct trace_array {
 164         struct ring_buffer      *buffer;
 165         unsigned long           entries;
 166         int                     cpu;
 167         cycle_t                 time_start;
 168         struct task_struct      *waiter;
 169         struct trace_array_cpu  *data[NR_CPUS];
 170 };
 171
 172 #define FTRACE_CMP_TYPE(var, type) \
 173         __builtin_types_compatible_p(typeof(var), type *)
 174
 175 #undef IF_ASSIGN
 176 #define IF_ASSIGN(var, entry, etype, id)                \
 177         if (FTRACE_CMP_TYPE(var, etype)) {              \
 178                 var = (typeof(var))(entry);             \
 179                 WARN_ON(id && (entry)->type != id);     \
 180                 break;                                  \
 181         }
 182
 183 /* Will cause compile errors if type is not found. */
 184 extern void __ftrace_bad_type(void);
 185
 186 /*
 187  * The trace_assign_type is a verifier that the entry type is
 188  * the same as the type being assigned. To add new types simply
 189  * add a line with the following format:
 190  *
 191  * IF_ASSIGN(var, ent, type, id);
 192  *
 193  *  Where "type" is the trace type that includes the trace_entry
 194  *  as the "ent" item. And "id" is the trace identifier that is
 195  *  used in the trace_type enum.
 196  *
 197  *  If the type can have more than one id, then use zero.
 198  */
 199 #define trace_assign_type(var, ent)                                     \
 200         do {                                                            \
 201                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 202                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 203                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 204                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 205                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 206                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 207                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 208                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 209                           TRACE_MMIO_RW);                               \
 210                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 211                           TRACE_MMIO_MAP);                              \
 212                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 213                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 214                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 215                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 216                           TRACE_GRAPH_ENT);             \
 217                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 218                           TRACE_GRAPH_RET);             \
 219                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 220                           TRACE_KMEM_ALLOC);    \
 221                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 222                           TRACE_KMEM_FREE);     \
 223                 IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\
 224                 __ftrace_bad_type();                                    \
 225         } while (0)
 226
 227 /*
 228  * An option specific to a tracer. This is a boolean value.
 229  * The bit is the bit index that sets its value on the
 230  * flags value in struct tracer_flags.
 231  */
 232 struct tracer_opt {
 233         const char      *name; /* Will appear on the trace_options file */
 234         u32             bit; /* Mask assigned in val field in tracer_flags */
 235 };
 236
 237 /*
 238  * The set of specific options for a tracer. Your tracer
 239  * have to set the initial value of the flags val.
 240  */
 241 struct tracer_flags {
 242         u32                     val;
 243         struct tracer_opt       *opts;
 244 };
 245
 246 /* Makes more easy to define a tracer opt */
 247 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 248
 249
 250 /**
 251  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 252  * @name: the name chosen to select it on the available_tracers file
 253  * @init: called when one switches to this tracer (echo name > current_tracer)
 254  * @reset: called when one switches to another tracer
 255  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 256  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 257  * @open: called when the trace file is opened
 258  * @pipe_open: called when the trace_pipe file is opened
 259  * @wait_pipe: override how the user waits for traces on trace_pipe
 260  * @close: called when the trace file is released
 261  * @pipe_close: called when the trace_pipe file is released
 262  * @read: override the default read callback on trace_pipe
 263  * @splice_read: override the default splice_read callback on trace_pipe
 264  * @selftest: selftest to run on boot (see trace_selftest.c)
 265  * @print_headers: override the first lines that describe your columns
 266  * @print_line: callback that prints a trace
 267  * @set_flag: signals one of your private flags changed (trace_options file)
 268  * @flags: your private flags
 269  */
 270 struct tracer {
 271         const char              *name;
 272         int                     (*init)(struct trace_array *tr);
 273         void                    (*reset)(struct trace_array *tr);
 274         void                    (*start)(struct trace_array *tr);
 275         void                    (*stop)(struct trace_array *tr);
 276         void                    (*open)(struct trace_iterator *iter);
 277         void                    (*pipe_open)(struct trace_iterator *iter);
 278         void                    (*wait_pipe)(struct trace_iterator *iter);
 279         void                    (*close)(struct trace_iterator *iter);
 280         void                    (*pipe_close)(struct trace_iterator *iter);
 281         ssize_t                 (*read)(struct trace_iterator *iter,
 282                                         struct file *filp, char __user *ubuf,
 283                                         size_t cnt, loff_t *ppos);
 284         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 285                                                struct file *filp,
 286                                                loff_t *ppos,
 287                                                struct pipe_inode_info *pipe,
 288                                                size_t len,
 289                                                unsigned int flags);
 290 #ifdef CONFIG_FTRACE_STARTUP_TEST
 291         int                     (*selftest)(struct tracer *trace,
 292                                             struct trace_array *tr);
 293 #endif
 294         void                    (*print_header)(struct seq_file *m);
 295         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 296         /* If you handled the flag setting, return 0 */
 297         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 298         struct tracer           *next;
 299         int                     print_max;
 300         struct tracer_flags     *flags;
 301 };
 302
 303
 304 #define TRACE_PIPE_ALL_CPU      -1
 305
 306 int tracer_init(struct tracer *t, struct trace_array *tr);
 307 int tracing_is_enabled(void);
 308 void trace_wake_up(void);
 309 void tracing_reset(struct trace_array *tr, int cpu);
 310 void tracing_reset_online_cpus(struct trace_array *tr);
 311 void tracing_reset_current(int cpu);
 312 void tracing_reset_current_online_cpus(void);
 313 int tracing_open_generic(struct inode *inode, struct file *filp);
 314 struct dentry *trace_create_file(const char *name,
 315                                  mode_t mode,
 316                                  struct dentry *parent,
 317                                  void *data,
 318                                  const struct file_operations *fops);
 319
 320 struct dentry *tracing_init_dentry(void);
 321 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 322
 323 struct ring_buffer_event;
 324
 325 struct ring_buffer_event *
 326 trace_buffer_lock_reserve(struct ring_buffer *buffer,
 327                           int type,
 328                           unsigned long len,
 329                           unsigned long flags,
 330                           int pc);
 331 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
 332                                 struct ring_buffer_event *event,
 333                                 unsigned long flags, int pc);
 334
 335 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 336                                                 struct trace_array_cpu *data);
 337
 338 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 339                                           int *ent_cpu, u64 *ent_ts);
 340
 341 int trace_empty(struct trace_iterator *iter);
 342
 343 void *trace_find_next_entry_inc(struct trace_iterator *iter);
 344
 345 void trace_init_global_iter(struct trace_iterator *iter);
 346
 347 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
 348
 349 void default_wait_pipe(struct trace_iterator *iter);
 350 void poll_wait_pipe(struct trace_iterator *iter);
 351
 352 void ftrace(struct trace_array *tr,
 353                             struct trace_array_cpu *data,
 354                             unsigned long ip,
 355                             unsigned long parent_ip,
 356                             unsigned long flags, int pc);
 357 void tracing_sched_switch_trace(struct trace_array *tr,
 358                                 struct task_struct *prev,
 359                                 struct task_struct *next,
 360                                 unsigned long flags, int pc);
 361
 362 void tracing_sched_wakeup_trace(struct trace_array *tr,
 363                                 struct task_struct *wakee,
 364                                 struct task_struct *cur,
 365                                 unsigned long flags, int pc);
 366 void trace_special(struct trace_array *tr,
 367                    struct trace_array_cpu *data,
 368                    unsigned long arg1,
 369                    unsigned long arg2,
 370                    unsigned long arg3, int pc);
 371 void trace_function(struct trace_array *tr,
 372                     unsigned long ip,
 373                     unsigned long parent_ip,
 374                     unsigned long flags, int pc);
 375 void trace_default_header(struct seq_file *m);
 376 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
 377 int trace_empty(struct trace_iterator *iter);
 378
 379 void trace_graph_return(struct ftrace_graph_ret *trace);
 380 int trace_graph_entry(struct ftrace_graph_ent *trace);
 381 void set_graph_array(struct trace_array *tr);
 382
 383 void tracing_start_cmdline_record(void);
 384 void tracing_stop_cmdline_record(void);
 385 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 386 void tracing_stop_sched_switch_record(void);
 387 void tracing_start_sched_switch_record(void);
 388 int register_tracer(struct tracer *type);
 389 void unregister_tracer(struct tracer *type);
 390 int is_tracing_stopped(void);
 391 enum trace_file_type {
 392         TRACE_FILE_LAT_FMT      = 1,
 393         TRACE_FILE_ANNOTATE     = 2,
 394 };
 395
 396 extern cpumask_var_t __read_mostly tracing_buffer_mask;
 397
 398 #define for_each_tracing_cpu(cpu)       \
 399         for_each_cpu(cpu, tracing_buffer_mask)
 400
 401 extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr);
 402
 403 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 404
 405 extern unsigned long tracing_thresh;
 406
 407 #ifdef CONFIG_TRACER_MAX_TRACE
 408 extern unsigned long tracing_max_latency;
 409
 410 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 411 void update_max_tr_single(struct trace_array *tr,
 412                           struct task_struct *tsk, int cpu);
 413 #endif /* CONFIG_TRACER_MAX_TRACE */
 414
 415 #ifdef CONFIG_STACKTRACE
 416 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 417                         int skip, int pc);
 418
 419 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 420                             int pc);
 421
 422 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 423                    int pc);
 424 #else
 425 static inline void ftrace_trace_stack(struct ring_buffer *buffer,
 426                                       unsigned long flags, int skip, int pc)
 427 {
 428 }
 429
 430 static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
 431                                           unsigned long flags, int pc)
 432 {
 433 }
 434
 435 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 436                                  int skip, int pc)
 437 {
 438 }
 439 #endif /* CONFIG_STACKTRACE */
 440
 441 extern cycle_t ftrace_now(int cpu);
 442
 443 extern void trace_find_cmdline(int pid, char comm[]);
 444
 445 #ifdef CONFIG_DYNAMIC_FTRACE
 446 extern unsigned long ftrace_update_tot_cnt;
 447 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 448 extern int DYN_FTRACE_TEST_NAME(void);
 449 #endif
 450
 451 extern int ring_buffer_expanded;
 452 extern bool tracing_selftest_disabled;
 453 DECLARE_PER_CPU(int, ftrace_cpu_disabled);
 454
 455 #ifdef CONFIG_FTRACE_STARTUP_TEST
 456 extern int trace_selftest_startup_function(struct tracer *trace,
 457                                            struct trace_array *tr);
 458 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 459                                                  struct trace_array *tr);
 460 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 461                                           struct trace_array *tr);
 462 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 463                                              struct trace_array *tr);
 464 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 465                                                  struct trace_array *tr);
 466 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 467                                          struct trace_array *tr);
 468 extern int trace_selftest_startup_nop(struct tracer *trace,
 469                                          struct trace_array *tr);
 470 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 471                                                struct trace_array *tr);
 472 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 473                                                struct trace_array *tr);
 474 extern int trace_selftest_startup_branch(struct tracer *trace,
 475                                          struct trace_array *tr);
 476 extern int trace_selftest_startup_ksym(struct tracer *trace,
 477                                          struct trace_array *tr);
 478 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 479
 480 extern void *head_page(struct trace_array_cpu *data);
 481 extern unsigned long long ns2usecs(cycle_t nsec);
 482 extern int
 483 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 484 extern int
 485 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 486 extern int
 487 trace_array_vprintk(struct trace_array *tr,
 488                     unsigned long ip, const char *fmt, va_list args);
 489 int trace_array_printk(struct trace_array *tr,
 490                        unsigned long ip, const char *fmt, ...);
 491 void trace_printk_seq(struct trace_seq *s);
 492 enum print_line_t print_trace_line(struct trace_iterator *iter);
 493
 494 extern unsigned long trace_flags;
 495
 496 extern int trace_clock_id;
 497
 498 /* Standard output formatting function used for function return traces */
 499 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 500
 501 /* Flag options */
 502 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
 503 #define TRACE_GRAPH_PRINT_CPU           0x2
 504 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
 505 #define TRACE_GRAPH_PRINT_PROC          0x8
 506 #define TRACE_GRAPH_PRINT_DURATION      0x10
 507 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
 508
 509 extern enum print_line_t
 510 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
 511 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
 512 extern enum print_line_t
 513 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 514 extern void graph_trace_open(struct trace_iterator *iter);
 515 extern void graph_trace_close(struct trace_iterator *iter);
 516 extern int __trace_graph_entry(struct trace_array *tr,
 517                                struct ftrace_graph_ent *trace,
 518                                unsigned long flags, int pc);
 519 extern void __trace_graph_return(struct trace_array *tr,
 520                                  struct ftrace_graph_ret *trace,
 521                                  unsigned long flags, int pc);
 522
 523
 524 #ifdef CONFIG_DYNAMIC_FTRACE
 525 /* TODO: make this variable */
 526 #define FTRACE_GRAPH_MAX_FUNCS          32
 527 extern int ftrace_graph_filter_enabled;
 528 extern int ftrace_graph_count;
 529 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 530
 531 static inline int ftrace_graph_addr(unsigned long addr)
 532 {
 533         int i;
 534
 535         if (!ftrace_graph_filter_enabled)
 536                 return 1;
 537
 538         for (i = 0; i < ftrace_graph_count; i++) {
 539                 if (addr == ftrace_graph_funcs[i])
 540                         return 1;
 541         }
 542
 543         return 0;
 544 }
 545 #else
 546 static inline int ftrace_graph_addr(unsigned long addr)
 547 {
 548         return 1;
 549 }
 550 #endif /* CONFIG_DYNAMIC_FTRACE */
 551 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 552 static inline enum print_line_t
 553 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 554 {
 555         return TRACE_TYPE_UNHANDLED;
 556 }
 557 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 558
 559 extern struct list_head ftrace_pids;
 560
 561 #ifdef CONFIG_FUNCTION_TRACER
 562 static inline int ftrace_trace_task(struct task_struct *task)
 563 {
 564         if (list_empty(&ftrace_pids))
 565                 return 1;
 566
 567         return test_tsk_trace_trace(task);
 568 }
 569 #else
 570 static inline int ftrace_trace_task(struct task_struct *task)
 571 {
 572         return 1;
 573 }
 574 #endif
 575
 576 /*
 577  * struct trace_parser - servers for reading the user input separated by spaces
 578  * @cont: set if the input is not complete - no final space char was found
 579  * @buffer: holds the parsed user input
 580  * @idx: user input length
 581  * @size: buffer size
 582  */
 583 struct trace_parser {
 584         bool            cont;
 585         char            *buffer;
 586         unsigned        idx;
 587         unsigned        size;
 588 };
 589
 590 static inline bool trace_parser_loaded(struct trace_parser *parser)
 591 {
 592         return (parser->idx != 0);
 593 }
 594
 595 static inline bool trace_parser_cont(struct trace_parser *parser)
 596 {
 597         return parser->cont;
 598 }
 599
 600 static inline void trace_parser_clear(struct trace_parser *parser)
 601 {
 602         parser->cont = false;
 603         parser->idx = 0;
 604 }
 605
 606 extern int trace_parser_get_init(struct trace_parser *parser, int size);
 607 extern void trace_parser_put(struct trace_parser *parser);
 608 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 609         size_t cnt, loff_t *ppos);
 610
 611 /*
 612  * trace_iterator_flags is an enumeration that defines bit
 613  * positions into trace_flags that controls the output.
 614  *
 615  * NOTE: These bits must match the trace_options array in
 616  *       trace.c.
 617  */
 618 enum trace_iterator_flags {
 619         TRACE_ITER_PRINT_PARENT         = 0x01,
 620         TRACE_ITER_SYM_OFFSET           = 0x02,
 621         TRACE_ITER_SYM_ADDR             = 0x04,
 622         TRACE_ITER_VERBOSE              = 0x08,
 623         TRACE_ITER_RAW                  = 0x10,
 624         TRACE_ITER_HEX                  = 0x20,
 625         TRACE_ITER_BIN                  = 0x40,
 626         TRACE_ITER_BLOCK                = 0x80,
 627         TRACE_ITER_STACKTRACE           = 0x100,
 628         TRACE_ITER_PRINTK               = 0x200,
 629         TRACE_ITER_PREEMPTONLY          = 0x400,
 630         TRACE_ITER_BRANCH               = 0x800,
 631         TRACE_ITER_ANNOTATE             = 0x1000,
 632         TRACE_ITER_USERSTACKTRACE       = 0x2000,
 633         TRACE_ITER_SYM_USEROBJ          = 0x4000,
 634         TRACE_ITER_PRINTK_MSGONLY       = 0x8000,
 635         TRACE_ITER_CONTEXT_INFO         = 0x10000, /* Print pid/cpu/time */
 636         TRACE_ITER_LATENCY_FMT          = 0x20000,
 637         TRACE_ITER_SLEEP_TIME           = 0x40000,
 638         TRACE_ITER_GRAPH_TIME           = 0x80000,
 639 };
 640
 641 /*
 642  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 643  * control the output of kernel symbols.
 644  */
 645 #define TRACE_ITER_SYM_MASK \
 646         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 647
 648 extern struct tracer nop_trace;
 649
 650 /**
 651  * ftrace_preempt_disable - disable preemption scheduler safe
 652  *
 653  * When tracing can happen inside the scheduler, there exists
 654  * cases that the tracing might happen before the need_resched
 655  * flag is checked. If this happens and the tracer calls
 656  * preempt_enable (after a disable), a schedule might take place
 657  * causing an infinite recursion.
 658  *
 659  * To prevent this, we read the need_resched flag before
 660  * disabling preemption. When we want to enable preemption we
 661  * check the flag, if it is set, then we call preempt_enable_no_resched.
 662  * Otherwise, we call preempt_enable.
 663  *
 664  * The rational for doing the above is that if need_resched is set
 665  * and we have yet to reschedule, we are either in an atomic location
 666  * (where we do not need to check for scheduling) or we are inside
 667  * the scheduler and do not want to resched.
 668  */
 669 static inline int ftrace_preempt_disable(void)
 670 {
 671         int resched;
 672
 673         resched = need_resched();
 674         preempt_disable_notrace();
 675
 676         return resched;
 677 }
 678
 679 /**
 680  * ftrace_preempt_enable - enable preemption scheduler safe
 681  * @resched: the return value from ftrace_preempt_disable
 682  *
 683  * This is a scheduler safe way to enable preemption and not miss
 684  * any preemption checks. The disabled saved the state of preemption.
 685  * If resched is set, then we are either inside an atomic or
 686  * are inside the scheduler (we would have already scheduled
 687  * otherwise). In this case, we do not want to call normal
 688  * preempt_enable, but preempt_enable_no_resched instead.
 689  */
 690 static inline void ftrace_preempt_enable(int resched)
 691 {
 692         if (resched)
 693                 preempt_enable_no_resched_notrace();
 694         else
 695                 preempt_enable_notrace();
 696 }
 697
 698 #ifdef CONFIG_BRANCH_TRACER
 699 extern int enable_branch_tracing(struct trace_array *tr);
 700 extern void disable_branch_tracing(void);
 701 static inline int trace_branch_enable(struct trace_array *tr)
 702 {
 703         if (trace_flags & TRACE_ITER_BRANCH)
 704                 return enable_branch_tracing(tr);
 705         return 0;
 706 }
 707 static inline void trace_branch_disable(void)
 708 {
 709         /* due to races, always disable */
 710         disable_branch_tracing();
 711 }
 712 #else
 713 static inline int trace_branch_enable(struct trace_array *tr)
 714 {
 715         return 0;
 716 }
 717 static inline void trace_branch_disable(void)
 718 {
 719 }
 720 #endif /* CONFIG_BRANCH_TRACER */
 721
 722 /* set ring buffers to default size if not already done so */
 723 int tracing_update_buffers(void);
 724
 725 /* trace event type bit fields, not numeric */
 726 enum {
 727         TRACE_EVENT_TYPE_PRINTF         = 1,
 728         TRACE_EVENT_TYPE_RAW            = 2,
 729 };
 730
 731 struct ftrace_event_field {
 732         struct list_head        link;
 733         char                    *name;
 734         char                    *type;
 735         int                     filter_type;
 736         int                     offset;
 737         int                     size;
 738         int                     is_signed;
 739 };
 740
 741 struct event_filter {
 742         int                     n_preds;
 743         struct filter_pred      **preds;
 744         char                    *filter_string;
 745 };
 746
 747 struct event_subsystem {
 748         struct list_head        list;
 749         const char              *name;
 750         struct dentry           *entry;
 751         struct event_filter     *filter;
 752         int                     nr_events;
 753 };
 754
 755 struct filter_pred;
 756 struct regex;
 757
 758 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 759                                  int val1, int val2);
 760
 761 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
 762
 763 enum regex_type {
 764         MATCH_FULL = 0,
 765         MATCH_FRONT_ONLY,
 766         MATCH_MIDDLE_ONLY,
 767         MATCH_END_ONLY,
 768 };
 769
 770 struct regex {
 771         char                    pattern[MAX_FILTER_STR_VAL];
 772         int                     len;
 773         int                     field_len;
 774         regex_match_func        match;
 775 };
 776
 777 struct filter_pred {
 778         filter_pred_fn_t        fn;
 779         u64                     val;
 780         struct regex            regex;
 781         char                    *field_name;
 782         int                     offset;
 783         int                     not;
 784         int                     op;
 785         int                     pop_n;
 786 };
 787
 788 extern enum regex_type
 789 filter_parse_regex(char *buff, int len, char **search, int *not);
 790 extern void print_event_filter(struct ftrace_event_call *call,
 791                                struct trace_seq *s);
 792 extern int apply_event_filter(struct ftrace_event_call *call,
 793                               char *filter_string);
 794 extern int apply_subsystem_event_filter(struct event_subsystem *system,
 795                                         char *filter_string);
 796 extern void print_subsystem_event_filter(struct event_subsystem *system,
 797                                          struct trace_seq *s);
 798 extern int filter_assign_type(const char *type);
 799
 800 struct list_head *
 801 trace_get_fields(struct ftrace_event_call *event_call);
 802
 803 static inline int
 804 filter_check_discard(struct ftrace_event_call *call, void *rec,
 805                      struct ring_buffer *buffer,
 806                      struct ring_buffer_event *event)
 807 {
 808         if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
 809             !filter_match_preds(call->filter, rec)) {
 810                 ring_buffer_discard_commit(buffer, event);
 811                 return 1;
 812         }
 813
 814         return 0;
 815 }
 816
 817 extern struct mutex event_mutex;
 818 extern struct list_head ftrace_events;
 819
 820 extern const char *__start___trace_bprintk_fmt[];
 821 extern const char *__stop___trace_bprintk_fmt[];
 822
 823 #undef FTRACE_ENTRY
 824 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)             \
 825         extern struct ftrace_event_call                                 \
 826         __attribute__((__aligned__(4))) event_##call;
 827 #undef FTRACE_ENTRY_DUP
 828 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)         \
 829         FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 830 #include "trace_entries.h"
 831
 832 #endif /* _LINUX_KERNEL_TRACE_H */