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/ftrace.h>
  11 #include <trace/boot.h>
  12 #include <linux/kmemtrace.h>
  13 #include <trace/power.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_POWER,
  40         TRACE_BLK,
  41
  42         __TRACE_LAST_TYPE,
  43 };
  44
  45 /*
  46  * Function trace entry - function address and parent function addres:
  47  */
  48 struct ftrace_entry {
  49         struct trace_entry      ent;
  50         unsigned long           ip;
  51         unsigned long           parent_ip;
  52 };
  53
  54 /* Function call entry */
  55 struct ftrace_graph_ent_entry {
  56         struct trace_entry              ent;
  57         struct ftrace_graph_ent         graph_ent;
  58 };
  59
  60 /* Function return entry */
  61 struct ftrace_graph_ret_entry {
  62         struct trace_entry              ent;
  63         struct ftrace_graph_ret         ret;
  64 };
  65 extern struct tracer boot_tracer;
  66
  67 /*
  68  * Context switch trace entry - which task (and prio) we switched from/to:
  69  */
  70 struct ctx_switch_entry {
  71         struct trace_entry      ent;
  72         unsigned int            prev_pid;
  73         unsigned char           prev_prio;
  74         unsigned char           prev_state;
  75         unsigned int            next_pid;
  76         unsigned char           next_prio;
  77         unsigned char           next_state;
  78         unsigned int            next_cpu;
  79 };
  80
  81 /*
  82  * Special (free-form) trace entry:
  83  */
  84 struct special_entry {
  85         struct trace_entry      ent;
  86         unsigned long           arg1;
  87         unsigned long           arg2;
  88         unsigned long           arg3;
  89 };
  90
  91 /*
  92  * Stack-trace entry:
  93  */
  94
  95 #define FTRACE_STACK_ENTRIES    8
  96
  97 struct stack_entry {
  98         struct trace_entry      ent;
  99         unsigned long           caller[FTRACE_STACK_ENTRIES];
 100 };
 101
 102 struct userstack_entry {
 103         struct trace_entry      ent;
 104         unsigned long           caller[FTRACE_STACK_ENTRIES];
 105 };
 106
 107 /*
 108  * trace_printk entry:
 109  */
 110 struct bprint_entry {
 111         struct trace_entry      ent;
 112         unsigned long           ip;
 113         const char              *fmt;
 114         u32                     buf[];
 115 };
 116
 117 struct print_entry {
 118         struct trace_entry      ent;
 119         unsigned long           ip;
 120         char                    buf[];
 121 };
 122
 123 #define TRACE_OLD_SIZE          88
 124
 125 struct trace_field_cont {
 126         unsigned char           type;
 127         /* Temporary till we get rid of this completely */
 128         char                    buf[TRACE_OLD_SIZE - 1];
 129 };
 130
 131 struct trace_mmiotrace_rw {
 132         struct trace_entry      ent;
 133         struct mmiotrace_rw     rw;
 134 };
 135
 136 struct trace_mmiotrace_map {
 137         struct trace_entry      ent;
 138         struct mmiotrace_map    map;
 139 };
 140
 141 struct trace_boot_call {
 142         struct trace_entry      ent;
 143         struct boot_trace_call boot_call;
 144 };
 145
 146 struct trace_boot_ret {
 147         struct trace_entry      ent;
 148         struct boot_trace_ret boot_ret;
 149 };
 150
 151 #define TRACE_FUNC_SIZE 30
 152 #define TRACE_FILE_SIZE 20
 153 struct trace_branch {
 154         struct trace_entry      ent;
 155         unsigned                line;
 156         char                    func[TRACE_FUNC_SIZE+1];
 157         char                    file[TRACE_FILE_SIZE+1];
 158         char                    correct;
 159 };
 160
 161 struct hw_branch_entry {
 162         struct trace_entry      ent;
 163         u64                     from;
 164         u64                     to;
 165 };
 166
 167 struct trace_power {
 168         struct trace_entry      ent;
 169         struct power_trace      state_data;
 170 };
 171
 172 enum kmemtrace_type_id {
 173         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
 174         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
 175         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
 176 };
 177
 178 struct kmemtrace_alloc_entry {
 179         struct trace_entry      ent;
 180         enum kmemtrace_type_id type_id;
 181         unsigned long call_site;
 182         const void *ptr;
 183         size_t bytes_req;
 184         size_t bytes_alloc;
 185         gfp_t gfp_flags;
 186         int node;
 187 };
 188
 189 struct kmemtrace_free_entry {
 190         struct trace_entry      ent;
 191         enum kmemtrace_type_id type_id;
 192         unsigned long call_site;
 193         const void *ptr;
 194 };
 195
 196 struct syscall_trace_enter {
 197         struct trace_entry      ent;
 198         int                     nr;
 199         unsigned long           args[];
 200 };
 201
 202 struct syscall_trace_exit {
 203         struct trace_entry      ent;
 204         int                     nr;
 205         unsigned long           ret;
 206 };
 207
 208
 209 /*
 210  * trace_flag_type is an enumeration that holds different
 211  * states when a trace occurs. These are:
 212  *  IRQS_OFF            - interrupts were disabled
 213  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 214  *  NEED_RESCED         - reschedule is requested
 215  *  HARDIRQ             - inside an interrupt handler
 216  *  SOFTIRQ             - inside a softirq handler
 217  */
 218 enum trace_flag_type {
 219         TRACE_FLAG_IRQS_OFF             = 0x01,
 220         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 221         TRACE_FLAG_NEED_RESCHED         = 0x04,
 222         TRACE_FLAG_HARDIRQ              = 0x08,
 223         TRACE_FLAG_SOFTIRQ              = 0x10,
 224 };
 225
 226 #define TRACE_BUF_SIZE          1024
 227
 228 /*
 229  * The CPU trace array - it consists of thousands of trace entries
 230  * plus some other descriptor data: (for example which task started
 231  * the trace, etc.)
 232  */
 233 struct trace_array_cpu {
 234         atomic_t                disabled;
 235         void                    *buffer_page;   /* ring buffer spare */
 236
 237         /* these fields get copied into max-trace: */
 238         unsigned long           trace_idx;
 239         unsigned long           overrun;
 240         unsigned long           saved_latency;
 241         unsigned long           critical_start;
 242         unsigned long           critical_end;
 243         unsigned long           critical_sequence;
 244         unsigned long           nice;
 245         unsigned long           policy;
 246         unsigned long           rt_priority;
 247         cycle_t                 preempt_timestamp;
 248         pid_t                   pid;
 249         uid_t                   uid;
 250         char                    comm[TASK_COMM_LEN];
 251 };
 252
 253 /*
 254  * The trace array - an array of per-CPU trace arrays. This is the
 255  * highest level data structure that individual tracers deal with.
 256  * They have on/off state as well:
 257  */
 258 struct trace_array {
 259         struct ring_buffer      *buffer;
 260         unsigned long           entries;
 261         int                     cpu;
 262         cycle_t                 time_start;
 263         struct task_struct      *waiter;
 264         struct trace_array_cpu  *data[NR_CPUS];
 265 };
 266
 267 #define FTRACE_CMP_TYPE(var, type) \
 268         __builtin_types_compatible_p(typeof(var), type *)
 269
 270 #undef IF_ASSIGN
 271 #define IF_ASSIGN(var, entry, etype, id)                \
 272         if (FTRACE_CMP_TYPE(var, etype)) {              \
 273                 var = (typeof(var))(entry);             \
 274                 WARN_ON(id && (entry)->type != id);     \
 275                 break;                                  \
 276         }
 277
 278 /* Will cause compile errors if type is not found. */
 279 extern void __ftrace_bad_type(void);
 280
 281 /*
 282  * The trace_assign_type is a verifier that the entry type is
 283  * the same as the type being assigned. To add new types simply
 284  * add a line with the following format:
 285  *
 286  * IF_ASSIGN(var, ent, type, id);
 287  *
 288  *  Where "type" is the trace type that includes the trace_entry
 289  *  as the "ent" item. And "id" is the trace identifier that is
 290  *  used in the trace_type enum.
 291  *
 292  *  If the type can have more than one id, then use zero.
 293  */
 294 #define trace_assign_type(var, ent)                                     \
 295         do {                                                            \
 296                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 297                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 298                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 299                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 300                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 301                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 302                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 303                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 304                           TRACE_MMIO_RW);                               \
 305                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 306                           TRACE_MMIO_MAP);                              \
 307                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 308                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 309                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 310                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 311                           TRACE_GRAPH_ENT);             \
 312                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 313                           TRACE_GRAPH_RET);             \
 314                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 315                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 316                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 317                           TRACE_KMEM_ALLOC);    \
 318                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 319                           TRACE_KMEM_FREE);     \
 320                 __ftrace_bad_type();                                    \
 321         } while (0)
 322
 323 /*
 324  * An option specific to a tracer. This is a boolean value.
 325  * The bit is the bit index that sets its value on the
 326  * flags value in struct tracer_flags.
 327  */
 328 struct tracer_opt {
 329         const char      *name; /* Will appear on the trace_options file */
 330         u32             bit; /* Mask assigned in val field in tracer_flags */
 331 };
 332
 333 /*
 334  * The set of specific options for a tracer. Your tracer
 335  * have to set the initial value of the flags val.
 336  */
 337 struct tracer_flags {
 338         u32                     val;
 339         struct tracer_opt       *opts;
 340 };
 341
 342 /* Makes more easy to define a tracer opt */
 343 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 344
 345
 346 /**
 347  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 348  * @name: the name chosen to select it on the available_tracers file
 349  * @init: called when one switches to this tracer (echo name > current_tracer)
 350  * @reset: called when one switches to another tracer
 351  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 352  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 353  * @open: called when the trace file is opened
 354  * @pipe_open: called when the trace_pipe file is opened
 355  * @wait_pipe: override how the user waits for traces on trace_pipe
 356  * @close: called when the trace file is released
 357  * @read: override the default read callback on trace_pipe
 358  * @splice_read: override the default splice_read callback on trace_pipe
 359  * @selftest: selftest to run on boot (see trace_selftest.c)
 360  * @print_headers: override the first lines that describe your columns
 361  * @print_line: callback that prints a trace
 362  * @set_flag: signals one of your private flags changed (trace_options file)
 363  * @flags: your private flags
 364  */
 365 struct tracer {
 366         const char              *name;
 367         int                     (*init)(struct trace_array *tr);
 368         void                    (*reset)(struct trace_array *tr);
 369         void                    (*start)(struct trace_array *tr);
 370         void                    (*stop)(struct trace_array *tr);
 371         void                    (*open)(struct trace_iterator *iter);
 372         void                    (*pipe_open)(struct trace_iterator *iter);
 373         void                    (*wait_pipe)(struct trace_iterator *iter);
 374         void                    (*close)(struct trace_iterator *iter);
 375         ssize_t                 (*read)(struct trace_iterator *iter,
 376                                         struct file *filp, char __user *ubuf,
 377                                         size_t cnt, loff_t *ppos);
 378         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 379                                                struct file *filp,
 380                                                loff_t *ppos,
 381                                                struct pipe_inode_info *pipe,
 382                                                size_t len,
 383                                                unsigned int flags);
 384 #ifdef CONFIG_FTRACE_STARTUP_TEST
 385         int                     (*selftest)(struct tracer *trace,
 386                                             struct trace_array *tr);
 387 #endif
 388         void                    (*print_header)(struct seq_file *m);
 389         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 390         /* If you handled the flag setting, return 0 */
 391         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 392         struct tracer           *next;
 393         int                     print_max;
 394         struct tracer_flags     *flags;
 395         struct tracer_stat      *stats;
 396 };
 397
 398
 399 #define TRACE_PIPE_ALL_CPU      -1
 400
 401 int tracer_init(struct tracer *t, struct trace_array *tr);
 402 int tracing_is_enabled(void);
 403 void trace_wake_up(void);
 404 void tracing_reset(struct trace_array *tr, int cpu);
 405 void tracing_reset_online_cpus(struct trace_array *tr);
 406 void tracing_reset_current(int cpu);
 407 void tracing_reset_current_online_cpus(void);
 408 int tracing_open_generic(struct inode *inode, struct file *filp);
 409 struct dentry *trace_create_file(const char *name,
 410                                  mode_t mode,
 411                                  struct dentry *parent,
 412                                  void *data,
 413                                  const struct file_operations *fops);
 414
 415 struct dentry *tracing_init_dentry(void);
 416 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 417
 418 struct ring_buffer_event;
 419
 420 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
 421                                                     int type,
 422                                                     unsigned long len,
 423                                                     unsigned long flags,
 424                                                     int pc);
 425 void trace_buffer_unlock_commit(struct trace_array *tr,
 426                                 struct ring_buffer_event *event,
 427                                 unsigned long flags, int pc);
 428
 429 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 430                                                 struct trace_array_cpu *data);
 431
 432 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 433                                           int *ent_cpu, u64 *ent_ts);
 434
 435 void default_wait_pipe(struct trace_iterator *iter);
 436 void poll_wait_pipe(struct trace_iterator *iter);
 437
 438 void ftrace(struct trace_array *tr,
 439                             struct trace_array_cpu *data,
 440                             unsigned long ip,
 441                             unsigned long parent_ip,
 442                             unsigned long flags, int pc);
 443 void tracing_sched_switch_trace(struct trace_array *tr,
 444                                 struct task_struct *prev,
 445                                 struct task_struct *next,
 446                                 unsigned long flags, int pc);
 447
 448 void tracing_sched_wakeup_trace(struct trace_array *tr,
 449                                 struct task_struct *wakee,
 450                                 struct task_struct *cur,
 451                                 unsigned long flags, int pc);
 452 void trace_special(struct trace_array *tr,
 453                    struct trace_array_cpu *data,
 454                    unsigned long arg1,
 455                    unsigned long arg2,
 456                    unsigned long arg3, int pc);
 457 void trace_function(struct trace_array *tr,
 458                     unsigned long ip,
 459                     unsigned long parent_ip,
 460                     unsigned long flags, int pc);
 461
 462 void trace_graph_return(struct ftrace_graph_ret *trace);
 463 int trace_graph_entry(struct ftrace_graph_ent *trace);
 464 void set_graph_array(struct trace_array *tr);
 465
 466 void tracing_start_cmdline_record(void);
 467 void tracing_stop_cmdline_record(void);
 468 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 469 void tracing_stop_sched_switch_record(void);
 470 void tracing_start_sched_switch_record(void);
 471 int register_tracer(struct tracer *type);
 472 void unregister_tracer(struct tracer *type);
 473
 474 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 475
 476 extern unsigned long tracing_max_latency;
 477 extern unsigned long tracing_thresh;
 478
 479 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 480 void update_max_tr_single(struct trace_array *tr,
 481                           struct task_struct *tsk, int cpu);
 482
 483 #ifdef CONFIG_STACKTRACE
 484 void ftrace_trace_stack(struct trace_array *tr, unsigned long flags,
 485                         int skip, int pc);
 486
 487 void ftrace_trace_userstack(struct trace_array *tr, unsigned long flags,
 488                             int pc);
 489
 490 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 491                    int pc);
 492 #else
 493 static inline void ftrace_trace_stack(struct trace_array *tr,
 494                                       unsigned long flags, int skip, int pc)
 495 {
 496 }
 497
 498 static inline void ftrace_trace_userstack(struct trace_array *tr,
 499                                           unsigned long flags, int pc)
 500 {
 501 }
 502
 503 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 504                                  int skip, int pc)
 505 {
 506 }
 507 #endif /* CONFIG_STACKTRACE */
 508
 509 extern cycle_t ftrace_now(int cpu);
 510
 511 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 512 typedef void
 513 (*tracer_switch_func_t)(void *private,
 514                         void *__rq,
 515                         struct task_struct *prev,
 516                         struct task_struct *next);
 517
 518 struct tracer_switch_ops {
 519         tracer_switch_func_t            func;
 520         void                            *private;
 521         struct tracer_switch_ops        *next;
 522 };
 523 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 524
 525 extern void trace_find_cmdline(int pid, char comm[]);
 526
 527 #ifdef CONFIG_DYNAMIC_FTRACE
 528 extern unsigned long ftrace_update_tot_cnt;
 529 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 530 extern int DYN_FTRACE_TEST_NAME(void);
 531 #endif
 532
 533 extern int ring_buffer_expanded;
 534 extern bool tracing_selftest_disabled;
 535 DECLARE_PER_CPU(local_t, ftrace_cpu_disabled);
 536
 537 #ifdef CONFIG_FTRACE_STARTUP_TEST
 538 extern int trace_selftest_startup_function(struct tracer *trace,
 539                                            struct trace_array *tr);
 540 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 541                                                  struct trace_array *tr);
 542 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 543                                           struct trace_array *tr);
 544 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 545                                              struct trace_array *tr);
 546 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 547                                                  struct trace_array *tr);
 548 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 549                                          struct trace_array *tr);
 550 extern int trace_selftest_startup_nop(struct tracer *trace,
 551                                          struct trace_array *tr);
 552 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 553                                                struct trace_array *tr);
 554 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 555                                                struct trace_array *tr);
 556 extern int trace_selftest_startup_branch(struct tracer *trace,
 557                                          struct trace_array *tr);
 558 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
 559                                               struct trace_array *tr);
 560 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 561
 562 extern void *head_page(struct trace_array_cpu *data);
 563 extern unsigned long long ns2usecs(cycle_t nsec);
 564 extern int
 565 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 566 extern int
 567 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 568
 569 extern unsigned long trace_flags;
 570
 571 extern int trace_clock_id;
 572
 573 /* Standard output formatting function used for function return traces */
 574 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 575 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 576 extern enum print_line_t
 577 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 578
 579 #ifdef CONFIG_DYNAMIC_FTRACE
 580 /* TODO: make this variable */
 581 #define FTRACE_GRAPH_MAX_FUNCS          32
 582 extern int ftrace_graph_count;
 583 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 584
 585 static inline int ftrace_graph_addr(unsigned long addr)
 586 {
 587         int i;
 588
 589         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 590                 return 1;
 591
 592         for (i = 0; i < ftrace_graph_count; i++) {
 593                 if (addr == ftrace_graph_funcs[i])
 594                         return 1;
 595         }
 596
 597         return 0;
 598 }
 599 #else
 600 static inline int ftrace_trace_addr(unsigned long addr)
 601 {
 602         return 1;
 603 }
 604 static inline int ftrace_graph_addr(unsigned long addr)
 605 {
 606         return 1;
 607 }
 608 #endif /* CONFIG_DYNAMIC_FTRACE */
 609 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 610 static inline enum print_line_t
 611 print_graph_function(struct trace_iterator *iter)
 612 {
 613         return TRACE_TYPE_UNHANDLED;
 614 }
 615 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 616
 617 extern struct pid *ftrace_pid_trace;
 618
 619 #ifdef CONFIG_FUNCTION_TRACER
 620 static inline int ftrace_trace_task(struct task_struct *task)
 621 {
 622         if (!ftrace_pid_trace)
 623                 return 1;
 624
 625         return test_tsk_trace_trace(task);
 626 }
 627 #else
 628 static inline int ftrace_trace_task(struct task_struct *task)
 629 {
 630         return 1;
 631 }
 632 #endif
 633
 634 /*
 635  * trace_iterator_flags is an enumeration that defines bit
 636  * positions into trace_flags that controls the output.
 637  *
 638  * NOTE: These bits must match the trace_options array in
 639  *       trace.c.
 640  */
 641 enum trace_iterator_flags {
 642         TRACE_ITER_PRINT_PARENT         = 0x01,
 643         TRACE_ITER_SYM_OFFSET           = 0x02,
 644         TRACE_ITER_SYM_ADDR             = 0x04,
 645         TRACE_ITER_VERBOSE              = 0x08,
 646         TRACE_ITER_RAW                  = 0x10,
 647         TRACE_ITER_HEX                  = 0x20,
 648         TRACE_ITER_BIN                  = 0x40,
 649         TRACE_ITER_BLOCK                = 0x80,
 650         TRACE_ITER_STACKTRACE           = 0x100,
 651         TRACE_ITER_SCHED_TREE           = 0x200,
 652         TRACE_ITER_PRINTK               = 0x400,
 653         TRACE_ITER_PREEMPTONLY          = 0x800,
 654         TRACE_ITER_BRANCH               = 0x1000,
 655         TRACE_ITER_ANNOTATE             = 0x2000,
 656         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 657         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 658         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 659         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 660         TRACE_ITER_LATENCY_FMT          = 0x40000,
 661         TRACE_ITER_SLEEP_TIME           = 0x80000,
 662         TRACE_ITER_GRAPH_TIME           = 0x100000,
 663 };
 664
 665 /*
 666  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 667  * control the output of kernel symbols.
 668  */
 669 #define TRACE_ITER_SYM_MASK \
 670         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 671
 672 extern struct tracer nop_trace;
 673
 674 /**
 675  * ftrace_preempt_disable - disable preemption scheduler safe
 676  *
 677  * When tracing can happen inside the scheduler, there exists
 678  * cases that the tracing might happen before the need_resched
 679  * flag is checked. If this happens and the tracer calls
 680  * preempt_enable (after a disable), a schedule might take place
 681  * causing an infinite recursion.
 682  *
 683  * To prevent this, we read the need_resched flag before
 684  * disabling preemption. When we want to enable preemption we
 685  * check the flag, if it is set, then we call preempt_enable_no_resched.
 686  * Otherwise, we call preempt_enable.
 687  *
 688  * The rational for doing the above is that if need_resched is set
 689  * and we have yet to reschedule, we are either in an atomic location
 690  * (where we do not need to check for scheduling) or we are inside
 691  * the scheduler and do not want to resched.
 692  */
 693 static inline int ftrace_preempt_disable(void)
 694 {
 695         int resched;
 696
 697         resched = need_resched();
 698         preempt_disable_notrace();
 699
 700         return resched;
 701 }
 702
 703 /**
 704  * ftrace_preempt_enable - enable preemption scheduler safe
 705  * @resched: the return value from ftrace_preempt_disable
 706  *
 707  * This is a scheduler safe way to enable preemption and not miss
 708  * any preemption checks. The disabled saved the state of preemption.
 709  * If resched is set, then we are either inside an atomic or
 710  * are inside the scheduler (we would have already scheduled
 711  * otherwise). In this case, we do not want to call normal
 712  * preempt_enable, but preempt_enable_no_resched instead.
 713  */
 714 static inline void ftrace_preempt_enable(int resched)
 715 {
 716         if (resched)
 717                 preempt_enable_no_resched_notrace();
 718         else
 719                 preempt_enable_notrace();
 720 }
 721
 722 #ifdef CONFIG_BRANCH_TRACER
 723 extern int enable_branch_tracing(struct trace_array *tr);
 724 extern void disable_branch_tracing(void);
 725 static inline int trace_branch_enable(struct trace_array *tr)
 726 {
 727         if (trace_flags & TRACE_ITER_BRANCH)
 728                 return enable_branch_tracing(tr);
 729         return 0;
 730 }
 731 static inline void trace_branch_disable(void)
 732 {
 733         /* due to races, always disable */
 734         disable_branch_tracing();
 735 }
 736 #else
 737 static inline int trace_branch_enable(struct trace_array *tr)
 738 {
 739         return 0;
 740 }
 741 static inline void trace_branch_disable(void)
 742 {
 743 }
 744 #endif /* CONFIG_BRANCH_TRACER */
 745
 746 /* set ring buffers to default size if not already done so */
 747 int tracing_update_buffers(void);
 748
 749 /* trace event type bit fields, not numeric */
 750 enum {
 751         TRACE_EVENT_TYPE_PRINTF         = 1,
 752         TRACE_EVENT_TYPE_RAW            = 2,
 753 };
 754
 755 struct ftrace_event_field {
 756         struct list_head        link;
 757         char                    *name;
 758         char                    *type;
 759         int                     filter_type;
 760         int                     offset;
 761         int                     size;
 762         int                     is_signed;
 763 };
 764
 765 struct event_filter {
 766         int                     n_preds;
 767         struct filter_pred      **preds;
 768         char                    *filter_string;
 769         bool                    no_reset;
 770 };
 771
 772 struct event_subsystem {
 773         struct list_head        list;
 774         const char              *name;
 775         struct dentry           *entry;
 776         struct event_filter     *filter;
 777         int                     nr_events;
 778 };
 779
 780 struct filter_pred;
 781
 782 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 783                                  int val1, int val2);
 784
 785 struct filter_pred {
 786         filter_pred_fn_t fn;
 787         u64 val;
 788         char str_val[MAX_FILTER_STR_VAL];
 789         int str_len;
 790         char *field_name;
 791         int offset;
 792         int not;
 793         int op;
 794         int pop_n;
 795 };
 796
 797 extern void print_event_filter(struct ftrace_event_call *call,
 798                                struct trace_seq *s);
 799 extern int apply_event_filter(struct ftrace_event_call *call,
 800                               char *filter_string);
 801 extern int apply_subsystem_event_filter(struct event_subsystem *system,
 802                                         char *filter_string);
 803 extern void print_subsystem_event_filter(struct event_subsystem *system,
 804                                          struct trace_seq *s);
 805 extern int filter_assign_type(const char *type);
 806
 807 static inline int
 808 filter_check_discard(struct ftrace_event_call *call, void *rec,
 809                      struct ring_buffer *buffer,
 810                      struct ring_buffer_event *event)
 811 {
 812         if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) {
 813                 ring_buffer_discard_commit(buffer, event);
 814                 return 1;
 815         }
 816
 817         return 0;
 818 }
 819
 820 #define DEFINE_COMPARISON_PRED(type)                                    \
 821 static int filter_pred_##type(struct filter_pred *pred, void *event,    \
 822                               int val1, int val2)                       \
 823 {                                                                       \
 824         type *addr = (type *)(event + pred->offset);                    \
 825         type val = (type)pred->val;                                     \
 826         int match = 0;                                                  \
 827                                                                         \
 828         switch (pred->op) {                                             \
 829         case OP_LT:                                                     \
 830                 match = (*addr < val);                                  \
 831                 break;                                                  \
 832         case OP_LE:                                                     \
 833                 match = (*addr <= val);                                 \
 834                 break;                                                  \
 835         case OP_GT:                                                     \
 836                 match = (*addr > val);                                  \
 837                 break;                                                  \
 838         case OP_GE:                                                     \
 839                 match = (*addr >= val);                                 \
 840                 break;                                                  \
 841         default:                                                        \
 842                 break;                                                  \
 843         }                                                               \
 844                                                                         \
 845         return match;                                                   \
 846 }
 847
 848 #define DEFINE_EQUALITY_PRED(size)                                      \
 849 static int filter_pred_##size(struct filter_pred *pred, void *event,    \
 850                               int val1, int val2)                       \
 851 {                                                                       \
 852         u##size *addr = (u##size *)(event + pred->offset);              \
 853         u##size val = (u##size)pred->val;                               \
 854         int match;                                                      \
 855                                                                         \
 856         match = (val == *addr) ^ pred->not;                             \
 857                                                                         \
 858         return match;                                                   \
 859 }
 860
 861 extern struct mutex event_mutex;
 862 extern struct list_head ftrace_events;
 863
 864 extern const char *__start___trace_bprintk_fmt[];
 865 extern const char *__stop___trace_bprintk_fmt[];
 866
 867 #undef TRACE_EVENT_FORMAT
 868 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
 869         extern struct ftrace_event_call event_##call;
 870 #undef TRACE_EVENT_FORMAT_NOFILTER
 871 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt)
 872 #include "trace_event_types.h"
 873
 874 #endif /* _LINUX_KERNEL_TRACE_H */