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 #ifdef CONFIG_KSYM_TRACER
  19 #include <asm/hw_breakpoint.h>
  20 #endif
  21
  22 enum trace_type {
  23         __TRACE_FIRST_TYPE = 0,
  24
  25         TRACE_FN,
  26         TRACE_CTX,
  27         TRACE_WAKE,
  28         TRACE_STACK,
  29         TRACE_PRINT,
  30         TRACE_BPRINT,
  31         TRACE_SPECIAL,
  32         TRACE_MMIO_RW,
  33         TRACE_MMIO_MAP,
  34         TRACE_BRANCH,
  35         TRACE_BOOT_CALL,
  36         TRACE_BOOT_RET,
  37         TRACE_GRAPH_RET,
  38         TRACE_GRAPH_ENT,
  39         TRACE_USER_STACK,
  40         TRACE_HW_BRANCHES,
  41         TRACE_SYSCALL_ENTER,
  42         TRACE_SYSCALL_EXIT,
  43         TRACE_KMEM_ALLOC,
  44         TRACE_KMEM_FREE,
  45         TRACE_POWER,
  46         TRACE_BLK,
  47         TRACE_KSYM,
  48
  49         __TRACE_LAST_TYPE,
  50 };
  51
  52 /*
  53  * Function trace entry - function address and parent function addres:
  54  */
  55 struct ftrace_entry {
  56         struct trace_entry      ent;
  57         unsigned long           ip;
  58         unsigned long           parent_ip;
  59 };
  60
  61 /* Function call entry */
  62 struct ftrace_graph_ent_entry {
  63         struct trace_entry              ent;
  64         struct ftrace_graph_ent         graph_ent;
  65 };
  66
  67 /* Function return entry */
  68 struct ftrace_graph_ret_entry {
  69         struct trace_entry              ent;
  70         struct ftrace_graph_ret         ret;
  71 };
  72 extern struct tracer boot_tracer;
  73
  74 /*
  75  * Context switch trace entry - which task (and prio) we switched from/to:
  76  */
  77 struct ctx_switch_entry {
  78         struct trace_entry      ent;
  79         unsigned int            prev_pid;
  80         unsigned char           prev_prio;
  81         unsigned char           prev_state;
  82         unsigned int            next_pid;
  83         unsigned char           next_prio;
  84         unsigned char           next_state;
  85         unsigned int            next_cpu;
  86 };
  87
  88 /*
  89  * Special (free-form) trace entry:
  90  */
  91 struct special_entry {
  92         struct trace_entry      ent;
  93         unsigned long           arg1;
  94         unsigned long           arg2;
  95         unsigned long           arg3;
  96 };
  97
  98 /*
  99  * Stack-trace entry:
 100  */
 101
 102 #define FTRACE_STACK_ENTRIES    8
 103
 104 struct stack_entry {
 105         struct trace_entry      ent;
 106         unsigned long           caller[FTRACE_STACK_ENTRIES];
 107 };
 108
 109 struct userstack_entry {
 110         struct trace_entry      ent;
 111         unsigned long           caller[FTRACE_STACK_ENTRIES];
 112 };
 113
 114 /*
 115  * trace_printk entry:
 116  */
 117 struct bprint_entry {
 118         struct trace_entry      ent;
 119         unsigned long           ip;
 120         const char              *fmt;
 121         u32                     buf[];
 122 };
 123
 124 struct print_entry {
 125         struct trace_entry      ent;
 126         unsigned long           ip;
 127         char                    buf[];
 128 };
 129
 130 #define TRACE_OLD_SIZE          88
 131
 132 struct trace_field_cont {
 133         unsigned char           type;
 134         /* Temporary till we get rid of this completely */
 135         char                    buf[TRACE_OLD_SIZE - 1];
 136 };
 137
 138 struct trace_mmiotrace_rw {
 139         struct trace_entry      ent;
 140         struct mmiotrace_rw     rw;
 141 };
 142
 143 struct trace_mmiotrace_map {
 144         struct trace_entry      ent;
 145         struct mmiotrace_map    map;
 146 };
 147
 148 struct trace_boot_call {
 149         struct trace_entry      ent;
 150         struct boot_trace_call boot_call;
 151 };
 152
 153 struct trace_boot_ret {
 154         struct trace_entry      ent;
 155         struct boot_trace_ret boot_ret;
 156 };
 157
 158 #define TRACE_FUNC_SIZE 30
 159 #define TRACE_FILE_SIZE 20
 160 struct trace_branch {
 161         struct trace_entry      ent;
 162         unsigned                line;
 163         char                    func[TRACE_FUNC_SIZE+1];
 164         char                    file[TRACE_FILE_SIZE+1];
 165         char                    correct;
 166 };
 167
 168 struct hw_branch_entry {
 169         struct trace_entry      ent;
 170         u64                     from;
 171         u64                     to;
 172 };
 173
 174 struct trace_power {
 175         struct trace_entry      ent;
 176         struct power_trace      state_data;
 177 };
 178
 179 enum kmemtrace_type_id {
 180         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
 181         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
 182         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
 183 };
 184
 185 struct kmemtrace_alloc_entry {
 186         struct trace_entry      ent;
 187         enum kmemtrace_type_id type_id;
 188         unsigned long call_site;
 189         const void *ptr;
 190         size_t bytes_req;
 191         size_t bytes_alloc;
 192         gfp_t gfp_flags;
 193         int node;
 194 };
 195
 196 struct kmemtrace_free_entry {
 197         struct trace_entry      ent;
 198         enum kmemtrace_type_id type_id;
 199         unsigned long call_site;
 200         const void *ptr;
 201 };
 202
 203 struct syscall_trace_enter {
 204         struct trace_entry      ent;
 205         int                     nr;
 206         unsigned long           args[];
 207 };
 208
 209 struct syscall_trace_exit {
 210         struct trace_entry      ent;
 211         int                     nr;
 212         unsigned long           ret;
 213 };
 214
 215 #define KSYM_SELFTEST_ENTRY "ksym_selftest_dummy"
 216 extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr);
 217
 218 struct ksym_trace_entry {
 219         struct trace_entry      ent;
 220         unsigned long           ip;
 221         unsigned char           type;
 222         char                    ksym_name[KSYM_NAME_LEN];
 223         char                    cmd[TASK_COMM_LEN];
 224 };
 225
 226 /*
 227  * trace_flag_type is an enumeration that holds different
 228  * states when a trace occurs. These are:
 229  *  IRQS_OFF            - interrupts were disabled
 230  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 231  *  NEED_RESCED         - reschedule is requested
 232  *  HARDIRQ             - inside an interrupt handler
 233  *  SOFTIRQ             - inside a softirq handler
 234  */
 235 enum trace_flag_type {
 236         TRACE_FLAG_IRQS_OFF             = 0x01,
 237         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 238         TRACE_FLAG_NEED_RESCHED         = 0x04,
 239         TRACE_FLAG_HARDIRQ              = 0x08,
 240         TRACE_FLAG_SOFTIRQ              = 0x10,
 241 };
 242
 243 #define TRACE_BUF_SIZE          1024
 244
 245 /*
 246  * The CPU trace array - it consists of thousands of trace entries
 247  * plus some other descriptor data: (for example which task started
 248  * the trace, etc.)
 249  */
 250 struct trace_array_cpu {
 251         atomic_t                disabled;
 252         void                    *buffer_page;   /* ring buffer spare */
 253
 254         /* these fields get copied into max-trace: */
 255         unsigned long           trace_idx;
 256         unsigned long           overrun;
 257         unsigned long           saved_latency;
 258         unsigned long           critical_start;
 259         unsigned long           critical_end;
 260         unsigned long           critical_sequence;
 261         unsigned long           nice;
 262         unsigned long           policy;
 263         unsigned long           rt_priority;
 264         cycle_t                 preempt_timestamp;
 265         pid_t                   pid;
 266         uid_t                   uid;
 267         char                    comm[TASK_COMM_LEN];
 268 };
 269
 270 /*
 271  * The trace array - an array of per-CPU trace arrays. This is the
 272  * highest level data structure that individual tracers deal with.
 273  * They have on/off state as well:
 274  */
 275 struct trace_array {
 276         struct ring_buffer      *buffer;
 277         unsigned long           entries;
 278         int                     cpu;
 279         cycle_t                 time_start;
 280         struct task_struct      *waiter;
 281         struct trace_array_cpu  *data[NR_CPUS];
 282 };
 283
 284 #define FTRACE_CMP_TYPE(var, type) \
 285         __builtin_types_compatible_p(typeof(var), type *)
 286
 287 #undef IF_ASSIGN
 288 #define IF_ASSIGN(var, entry, etype, id)                \
 289         if (FTRACE_CMP_TYPE(var, etype)) {              \
 290                 var = (typeof(var))(entry);             \
 291                 WARN_ON(id && (entry)->type != id);     \
 292                 break;                                  \
 293         }
 294
 295 /* Will cause compile errors if type is not found. */
 296 extern void __ftrace_bad_type(void);
 297
 298 /*
 299  * The trace_assign_type is a verifier that the entry type is
 300  * the same as the type being assigned. To add new types simply
 301  * add a line with the following format:
 302  *
 303  * IF_ASSIGN(var, ent, type, id);
 304  *
 305  *  Where "type" is the trace type that includes the trace_entry
 306  *  as the "ent" item. And "id" is the trace identifier that is
 307  *  used in the trace_type enum.
 308  *
 309  *  If the type can have more than one id, then use zero.
 310  */
 311 #define trace_assign_type(var, ent)                                     \
 312         do {                                                            \
 313                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 314                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 315                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 316                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 317                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 318                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 319                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 320                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 321                           TRACE_MMIO_RW);                               \
 322                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 323                           TRACE_MMIO_MAP);                              \
 324                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 325                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 326                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 327                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 328                           TRACE_GRAPH_ENT);             \
 329                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 330                           TRACE_GRAPH_RET);             \
 331                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 332                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 333                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 334                           TRACE_KMEM_ALLOC);    \
 335                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 336                           TRACE_KMEM_FREE);     \
 337                 IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
 338                           TRACE_SYSCALL_ENTER);                         \
 339                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
 340                           TRACE_SYSCALL_EXIT);                          \
 341                 IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\
 342                 __ftrace_bad_type();                                    \
 343         } while (0)
 344
 345 /*
 346  * An option specific to a tracer. This is a boolean value.
 347  * The bit is the bit index that sets its value on the
 348  * flags value in struct tracer_flags.
 349  */
 350 struct tracer_opt {
 351         const char      *name; /* Will appear on the trace_options file */
 352         u32             bit; /* Mask assigned in val field in tracer_flags */
 353 };
 354
 355 /*
 356  * The set of specific options for a tracer. Your tracer
 357  * have to set the initial value of the flags val.
 358  */
 359 struct tracer_flags {
 360         u32                     val;
 361         struct tracer_opt       *opts;
 362 };
 363
 364 /* Makes more easy to define a tracer opt */
 365 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 366
 367
 368 /**
 369  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 370  * @name: the name chosen to select it on the available_tracers file
 371  * @init: called when one switches to this tracer (echo name > current_tracer)
 372  * @reset: called when one switches to another tracer
 373  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 374  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 375  * @open: called when the trace file is opened
 376  * @pipe_open: called when the trace_pipe file is opened
 377  * @wait_pipe: override how the user waits for traces on trace_pipe
 378  * @close: called when the trace file is released
 379  * @read: override the default read callback on trace_pipe
 380  * @splice_read: override the default splice_read callback on trace_pipe
 381  * @selftest: selftest to run on boot (see trace_selftest.c)
 382  * @print_headers: override the first lines that describe your columns
 383  * @print_line: callback that prints a trace
 384  * @set_flag: signals one of your private flags changed (trace_options file)
 385  * @flags: your private flags
 386  */
 387 struct tracer {
 388         const char              *name;
 389         int                     (*init)(struct trace_array *tr);
 390         void                    (*reset)(struct trace_array *tr);
 391         void                    (*start)(struct trace_array *tr);
 392         void                    (*stop)(struct trace_array *tr);
 393         void                    (*open)(struct trace_iterator *iter);
 394         void                    (*pipe_open)(struct trace_iterator *iter);
 395         void                    (*wait_pipe)(struct trace_iterator *iter);
 396         void                    (*close)(struct trace_iterator *iter);
 397         ssize_t                 (*read)(struct trace_iterator *iter,
 398                                         struct file *filp, char __user *ubuf,
 399                                         size_t cnt, loff_t *ppos);
 400         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 401                                                struct file *filp,
 402                                                loff_t *ppos,
 403                                                struct pipe_inode_info *pipe,
 404                                                size_t len,
 405                                                unsigned int flags);
 406 #ifdef CONFIG_FTRACE_STARTUP_TEST
 407         int                     (*selftest)(struct tracer *trace,
 408                                             struct trace_array *tr);
 409 #endif
 410         void                    (*print_header)(struct seq_file *m);
 411         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 412         /* If you handled the flag setting, return 0 */
 413         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 414         struct tracer           *next;
 415         int                     print_max;
 416         struct tracer_flags     *flags;
 417         struct tracer_stat      *stats;
 418 };
 419
 420
 421 #define TRACE_PIPE_ALL_CPU      -1
 422
 423 int tracer_init(struct tracer *t, struct trace_array *tr);
 424 int tracing_is_enabled(void);
 425 void trace_wake_up(void);
 426 void tracing_reset(struct trace_array *tr, int cpu);
 427 void tracing_reset_online_cpus(struct trace_array *tr);
 428 void tracing_reset_current(int cpu);
 429 void tracing_reset_current_online_cpus(void);
 430 int tracing_open_generic(struct inode *inode, struct file *filp);
 431 struct dentry *trace_create_file(const char *name,
 432                                  mode_t mode,
 433                                  struct dentry *parent,
 434                                  void *data,
 435                                  const struct file_operations *fops);
 436
 437 struct dentry *tracing_init_dentry(void);
 438 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 439
 440 struct ring_buffer_event;
 441
 442 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
 443                                                     int type,
 444                                                     unsigned long len,
 445                                                     unsigned long flags,
 446                                                     int pc);
 447 void trace_buffer_unlock_commit(struct trace_array *tr,
 448                                 struct ring_buffer_event *event,
 449                                 unsigned long flags, int pc);
 450
 451 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 452                                                 struct trace_array_cpu *data);
 453
 454 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 455                                           int *ent_cpu, u64 *ent_ts);
 456
 457 void tracing_generic_entry_update(struct trace_entry *entry,
 458                                   unsigned long flags,
 459                                   int pc);
 460
 461 void default_wait_pipe(struct trace_iterator *iter);
 462 void poll_wait_pipe(struct trace_iterator *iter);
 463
 464 void ftrace(struct trace_array *tr,
 465                             struct trace_array_cpu *data,
 466                             unsigned long ip,
 467                             unsigned long parent_ip,
 468                             unsigned long flags, int pc);
 469 void tracing_sched_switch_trace(struct trace_array *tr,
 470                                 struct task_struct *prev,
 471                                 struct task_struct *next,
 472                                 unsigned long flags, int pc);
 473
 474 void tracing_sched_wakeup_trace(struct trace_array *tr,
 475                                 struct task_struct *wakee,
 476                                 struct task_struct *cur,
 477                                 unsigned long flags, int pc);
 478 void trace_special(struct trace_array *tr,
 479                    struct trace_array_cpu *data,
 480                    unsigned long arg1,
 481                    unsigned long arg2,
 482                    unsigned long arg3, int pc);
 483 void trace_function(struct trace_array *tr,
 484                     unsigned long ip,
 485                     unsigned long parent_ip,
 486                     unsigned long flags, int pc);
 487
 488 void trace_graph_return(struct ftrace_graph_ret *trace);
 489 int trace_graph_entry(struct ftrace_graph_ent *trace);
 490
 491 void tracing_start_cmdline_record(void);
 492 void tracing_stop_cmdline_record(void);
 493 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 494 void tracing_stop_sched_switch_record(void);
 495 void tracing_start_sched_switch_record(void);
 496 int register_tracer(struct tracer *type);
 497 void unregister_tracer(struct tracer *type);
 498
 499 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 500
 501 extern unsigned long tracing_max_latency;
 502 extern unsigned long tracing_thresh;
 503
 504 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 505 void update_max_tr_single(struct trace_array *tr,
 506                           struct task_struct *tsk, int cpu);
 507
 508 void __trace_stack(struct trace_array *tr,
 509                    unsigned long flags,
 510                    int skip, int pc);
 511
 512 extern cycle_t ftrace_now(int cpu);
 513
 514 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 515 typedef void
 516 (*tracer_switch_func_t)(void *private,
 517                         void *__rq,
 518                         struct task_struct *prev,
 519                         struct task_struct *next);
 520
 521 struct tracer_switch_ops {
 522         tracer_switch_func_t            func;
 523         void                            *private;
 524         struct tracer_switch_ops        *next;
 525 };
 526 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 527
 528 extern void trace_find_cmdline(int pid, char comm[]);
 529
 530 #ifdef CONFIG_DYNAMIC_FTRACE
 531 extern unsigned long ftrace_update_tot_cnt;
 532 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 533 extern int DYN_FTRACE_TEST_NAME(void);
 534 #endif
 535
 536 #ifdef CONFIG_FTRACE_STARTUP_TEST
 537 extern int trace_selftest_startup_function(struct tracer *trace,
 538                                            struct trace_array *tr);
 539 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 540                                                  struct trace_array *tr);
 541 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 542                                           struct trace_array *tr);
 543 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 544                                              struct trace_array *tr);
 545 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 546                                                  struct trace_array *tr);
 547 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 548                                          struct trace_array *tr);
 549 extern int trace_selftest_startup_nop(struct tracer *trace,
 550                                          struct trace_array *tr);
 551 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 552                                                struct trace_array *tr);
 553 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 554                                                struct trace_array *tr);
 555 extern int trace_selftest_startup_branch(struct tracer *trace,
 556                                          struct trace_array *tr);
 557 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
 558                                               struct trace_array *tr);
 559 extern int trace_selftest_startup_ksym(struct tracer *trace,
 560                                          struct trace_array *tr);
 561 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 562
 563 extern void *head_page(struct trace_array_cpu *data);
 564 extern unsigned long long ns2usecs(cycle_t nsec);
 565 extern int
 566 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 567 extern int
 568 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 569
 570 extern unsigned long trace_flags;
 571
 572 /* Standard output formatting function used for function return traces */
 573 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 574 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 575 extern enum print_line_t
 576 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 577
 578 #ifdef CONFIG_DYNAMIC_FTRACE
 579 /* TODO: make this variable */
 580 #define FTRACE_GRAPH_MAX_FUNCS          32
 581 extern int ftrace_graph_count;
 582 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 583
 584 static inline int ftrace_graph_addr(unsigned long addr)
 585 {
 586         int i;
 587
 588         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 589                 return 1;
 590
 591         for (i = 0; i < ftrace_graph_count; i++) {
 592                 if (addr == ftrace_graph_funcs[i])
 593                         return 1;
 594         }
 595
 596         return 0;
 597 }
 598 #else
 599 static inline int ftrace_trace_addr(unsigned long addr)
 600 {
 601         return 1;
 602 }
 603 static inline int ftrace_graph_addr(unsigned long addr)
 604 {
 605         return 1;
 606 }
 607 #endif /* CONFIG_DYNAMIC_FTRACE */
 608 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 609 static inline enum print_line_t
 610 print_graph_function(struct trace_iterator *iter)
 611 {
 612         return TRACE_TYPE_UNHANDLED;
 613 }
 614 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 615
 616 extern struct pid *ftrace_pid_trace;
 617
 618 static inline int ftrace_trace_task(struct task_struct *task)
 619 {
 620         if (!ftrace_pid_trace)
 621                 return 1;
 622
 623         return test_tsk_trace_trace(task);
 624 }
 625
 626 /*
 627  * trace_iterator_flags is an enumeration that defines bit
 628  * positions into trace_flags that controls the output.
 629  *
 630  * NOTE: These bits must match the trace_options array in
 631  *       trace.c.
 632  */
 633 enum trace_iterator_flags {
 634         TRACE_ITER_PRINT_PARENT         = 0x01,
 635         TRACE_ITER_SYM_OFFSET           = 0x02,
 636         TRACE_ITER_SYM_ADDR             = 0x04,
 637         TRACE_ITER_VERBOSE              = 0x08,
 638         TRACE_ITER_RAW                  = 0x10,
 639         TRACE_ITER_HEX                  = 0x20,
 640         TRACE_ITER_BIN                  = 0x40,
 641         TRACE_ITER_BLOCK                = 0x80,
 642         TRACE_ITER_STACKTRACE           = 0x100,
 643         TRACE_ITER_SCHED_TREE           = 0x200,
 644         TRACE_ITER_PRINTK               = 0x400,
 645         TRACE_ITER_PREEMPTONLY          = 0x800,
 646         TRACE_ITER_BRANCH               = 0x1000,
 647         TRACE_ITER_ANNOTATE             = 0x2000,
 648         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 649         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 650         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 651         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 652         TRACE_ITER_LATENCY_FMT          = 0x40000,
 653         TRACE_ITER_GLOBAL_CLK           = 0x80000,
 654         TRACE_ITER_SLEEP_TIME           = 0x100000,
 655         TRACE_ITER_GRAPH_TIME           = 0x200000,
 656 };
 657
 658 /*
 659  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 660  * control the output of kernel symbols.
 661  */
 662 #define TRACE_ITER_SYM_MASK \
 663         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 664
 665 extern struct tracer nop_trace;
 666
 667 /**
 668  * ftrace_preempt_disable - disable preemption scheduler safe
 669  *
 670  * When tracing can happen inside the scheduler, there exists
 671  * cases that the tracing might happen before the need_resched
 672  * flag is checked. If this happens and the tracer calls
 673  * preempt_enable (after a disable), a schedule might take place
 674  * causing an infinite recursion.
 675  *
 676  * To prevent this, we read the need_resched flag before
 677  * disabling preemption. When we want to enable preemption we
 678  * check the flag, if it is set, then we call preempt_enable_no_resched.
 679  * Otherwise, we call preempt_enable.
 680  *
 681  * The rational for doing the above is that if need_resched is set
 682  * and we have yet to reschedule, we are either in an atomic location
 683  * (where we do not need to check for scheduling) or we are inside
 684  * the scheduler and do not want to resched.
 685  */
 686 static inline int ftrace_preempt_disable(void)
 687 {
 688         int resched;
 689
 690         resched = need_resched();
 691         preempt_disable_notrace();
 692
 693         return resched;
 694 }
 695
 696 /**
 697  * ftrace_preempt_enable - enable preemption scheduler safe
 698  * @resched: the return value from ftrace_preempt_disable
 699  *
 700  * This is a scheduler safe way to enable preemption and not miss
 701  * any preemption checks. The disabled saved the state of preemption.
 702  * If resched is set, then we are either inside an atomic or
 703  * are inside the scheduler (we would have already scheduled
 704  * otherwise). In this case, we do not want to call normal
 705  * preempt_enable, but preempt_enable_no_resched instead.
 706  */
 707 static inline void ftrace_preempt_enable(int resched)
 708 {
 709         if (resched)
 710                 preempt_enable_no_resched_notrace();
 711         else
 712                 preempt_enable_notrace();
 713 }
 714
 715 #ifdef CONFIG_BRANCH_TRACER
 716 extern int enable_branch_tracing(struct trace_array *tr);
 717 extern void disable_branch_tracing(void);
 718 static inline int trace_branch_enable(struct trace_array *tr)
 719 {
 720         if (trace_flags & TRACE_ITER_BRANCH)
 721                 return enable_branch_tracing(tr);
 722         return 0;
 723 }
 724 static inline void trace_branch_disable(void)
 725 {
 726         /* due to races, always disable */
 727         disable_branch_tracing();
 728 }
 729 #else
 730 static inline int trace_branch_enable(struct trace_array *tr)
 731 {
 732         return 0;
 733 }
 734 static inline void trace_branch_disable(void)
 735 {
 736 }
 737 #endif /* CONFIG_BRANCH_TRACER */
 738
 739 /* set ring buffers to default size if not already done so */
 740 int tracing_update_buffers(void);
 741
 742 /* trace event type bit fields, not numeric */
 743 enum {
 744         TRACE_EVENT_TYPE_PRINTF         = 1,
 745         TRACE_EVENT_TYPE_RAW            = 2,
 746 };
 747
 748 struct ftrace_event_field {
 749         struct list_head        link;
 750         char                    *name;
 751         char                    *type;
 752         int                     offset;
 753         int                     size;
 754         int                     is_signed;
 755 };
 756
 757 struct event_filter {
 758         int                     n_preds;
 759         struct filter_pred      **preds;
 760         char                    *filter_string;
 761 };
 762
 763 struct event_subsystem {
 764         struct list_head        list;
 765         const char              *name;
 766         struct dentry           *entry;
 767         void                    *filter;
 768 };
 769
 770 struct filter_pred;
 771
 772 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 773                                  int val1, int val2);
 774
 775 struct filter_pred {
 776         filter_pred_fn_t fn;
 777         u64 val;
 778         char str_val[MAX_FILTER_STR_VAL];
 779         int str_len;
 780         char *field_name;
 781         int offset;
 782         int not;
 783         int op;
 784         int pop_n;
 785 };
 786
 787 extern void print_event_filter(struct ftrace_event_call *call,
 788                                struct trace_seq *s);
 789 extern int apply_event_filter(struct ftrace_event_call *call,
 790                               char *filter_string);
 791 extern int apply_subsystem_event_filter(struct event_subsystem *system,
 792                                         char *filter_string);
 793 extern void print_subsystem_event_filter(struct event_subsystem *system,
 794                                          struct trace_seq *s);
 795
 796 static inline int
 797 filter_check_discard(struct ftrace_event_call *call, void *rec,
 798                      struct ring_buffer *buffer,
 799                      struct ring_buffer_event *event)
 800 {
 801         if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) {
 802                 ring_buffer_discard_commit(buffer, event);
 803                 return 1;
 804         }
 805
 806         return 0;
 807 }
 808
 809 #define DEFINE_COMPARISON_PRED(type)                                    \
 810 static int filter_pred_##type(struct filter_pred *pred, void *event,    \
 811                               int val1, int val2)                       \
 812 {                                                                       \
 813         type *addr = (type *)(event + pred->offset);                    \
 814         type val = (type)pred->val;                                     \
 815         int match = 0;                                                  \
 816                                                                         \
 817         switch (pred->op) {                                             \
 818         case OP_LT:                                                     \
 819                 match = (*addr < val);                                  \
 820                 break;                                                  \
 821         case OP_LE:                                                     \
 822                 match = (*addr <= val);                                 \
 823                 break;                                                  \
 824         case OP_GT:                                                     \
 825                 match = (*addr > val);                                  \
 826                 break;                                                  \
 827         case OP_GE:                                                     \
 828                 match = (*addr >= val);                                 \
 829                 break;                                                  \
 830         default:                                                        \
 831                 break;                                                  \
 832         }                                                               \
 833                                                                         \
 834         return match;                                                   \
 835 }
 836
 837 #define DEFINE_EQUALITY_PRED(size)                                      \
 838 static int filter_pred_##size(struct filter_pred *pred, void *event,    \
 839                               int val1, int val2)                       \
 840 {                                                                       \
 841         u##size *addr = (u##size *)(event + pred->offset);              \
 842         u##size val = (u##size)pred->val;                               \
 843         int match;                                                      \
 844                                                                         \
 845         match = (val == *addr) ^ pred->not;                             \
 846                                                                         \
 847         return match;                                                   \
 848 }
 849
 850 extern struct mutex event_mutex;
 851 extern struct list_head ftrace_events;
 852
 853 extern const char *__start___trace_bprintk_fmt[];
 854 extern const char *__stop___trace_bprintk_fmt[];
 855
 856 #undef TRACE_EVENT_FORMAT
 857 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
 858         extern struct ftrace_event_call event_##call;
 859 #undef TRACE_EVENT_FORMAT_NOFILTER
 860 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt)
 861 #include "trace_event_types.h"
 862
 863 #endif /* _LINUX_KERNEL_TRACE_H */