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 #include <trace/events/skb.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_HW_BRANCHES,
  38         TRACE_SYSCALL_ENTER,
  39         TRACE_SYSCALL_EXIT,
  40         TRACE_KMEM_ALLOC,
  41         TRACE_KMEM_FREE,
  42         TRACE_POWER,
  43         TRACE_BLK,
  44         TRACE_SKB_SOURCE,
  45
  46         __TRACE_LAST_TYPE,
  47 };
  48
  49 /*
  50  * Function trace entry - function address and parent function addres:
  51  */
  52 struct ftrace_entry {
  53         struct trace_entry      ent;
  54         unsigned long           ip;
  55         unsigned long           parent_ip;
  56 };
  57
  58 /* Function call entry */
  59 struct ftrace_graph_ent_entry {
  60         struct trace_entry              ent;
  61         struct ftrace_graph_ent         graph_ent;
  62 };
  63
  64 /* Function return entry */
  65 struct ftrace_graph_ret_entry {
  66         struct trace_entry              ent;
  67         struct ftrace_graph_ret         ret;
  68 };
  69 extern struct tracer boot_tracer;
  70
  71 /*
  72  * Context switch trace entry - which task (and prio) we switched from/to:
  73  */
  74 struct ctx_switch_entry {
  75         struct trace_entry      ent;
  76         unsigned int            prev_pid;
  77         unsigned char           prev_prio;
  78         unsigned char           prev_state;
  79         unsigned int            next_pid;
  80         unsigned char           next_prio;
  81         unsigned char           next_state;
  82         unsigned int            next_cpu;
  83 };
  84
  85 /*
  86  * Special (free-form) trace entry:
  87  */
  88 struct special_entry {
  89         struct trace_entry      ent;
  90         unsigned long           arg1;
  91         unsigned long           arg2;
  92         unsigned long           arg3;
  93 };
  94
  95 /*
  96  * Stack-trace entry:
  97  */
  98
  99 #define FTRACE_STACK_ENTRIES    8
 100
 101 struct stack_entry {
 102         struct trace_entry      ent;
 103         unsigned long           caller[FTRACE_STACK_ENTRIES];
 104 };
 105
 106 struct userstack_entry {
 107         struct trace_entry      ent;
 108         unsigned long           caller[FTRACE_STACK_ENTRIES];
 109 };
 110
 111 /*
 112  * trace_printk entry:
 113  */
 114 struct bprint_entry {
 115         struct trace_entry      ent;
 116         unsigned long           ip;
 117         const char              *fmt;
 118         u32                     buf[];
 119 };
 120
 121 struct print_entry {
 122         struct trace_entry      ent;
 123         unsigned long           ip;
 124         char                    buf[];
 125 };
 126
 127 #define TRACE_OLD_SIZE          88
 128
 129 struct trace_field_cont {
 130         unsigned char           type;
 131         /* Temporary till we get rid of this completely */
 132         char                    buf[TRACE_OLD_SIZE - 1];
 133 };
 134
 135 struct trace_mmiotrace_rw {
 136         struct trace_entry      ent;
 137         struct mmiotrace_rw     rw;
 138 };
 139
 140 struct trace_mmiotrace_map {
 141         struct trace_entry      ent;
 142         struct mmiotrace_map    map;
 143 };
 144
 145 struct trace_boot_call {
 146         struct trace_entry      ent;
 147         struct boot_trace_call boot_call;
 148 };
 149
 150 struct trace_boot_ret {
 151         struct trace_entry      ent;
 152         struct boot_trace_ret boot_ret;
 153 };
 154
 155 #define TRACE_FUNC_SIZE 30
 156 #define TRACE_FILE_SIZE 20
 157 struct trace_branch {
 158         struct trace_entry      ent;
 159         unsigned                line;
 160         char                    func[TRACE_FUNC_SIZE+1];
 161         char                    file[TRACE_FILE_SIZE+1];
 162         char                    correct;
 163 };
 164
 165 struct hw_branch_entry {
 166         struct trace_entry      ent;
 167         u64                     from;
 168         u64                     to;
 169 };
 170
 171 struct trace_power {
 172         struct trace_entry      ent;
 173         struct power_trace      state_data;
 174 };
 175
 176 struct skb_record {
 177         pid_t pid;              /* pid of the copying process */
 178         int anid;               /* node where skb was allocated */
 179         int cnid;               /* node to which skb was copied in userspace */
 180         char ifname[IFNAMSIZ];  /* Name of the receiving interface */
 181         int rx_queue;           /* The rx queue the skb was received on */
 182         int ccpu;               /* Cpu the application got this frame from */
 183         int len;                /* length of the data copied */
 184 };
 185
 186 struct trace_skb_event {
 187         struct trace_entry      ent;
 188         struct skb_record       event_data;
 189 };
 190
 191 enum kmemtrace_type_id {
 192         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
 193         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
 194         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
 195 };
 196
 197 struct kmemtrace_alloc_entry {
 198         struct trace_entry      ent;
 199         enum kmemtrace_type_id type_id;
 200         unsigned long call_site;
 201         const void *ptr;
 202         size_t bytes_req;
 203         size_t bytes_alloc;
 204         gfp_t gfp_flags;
 205         int node;
 206 };
 207
 208 struct kmemtrace_free_entry {
 209         struct trace_entry      ent;
 210         enum kmemtrace_type_id type_id;
 211         unsigned long call_site;
 212         const void *ptr;
 213 };
 214
 215 struct syscall_trace_enter {
 216         struct trace_entry      ent;
 217         int                     nr;
 218         unsigned long           args[];
 219 };
 220
 221 struct syscall_trace_exit {
 222         struct trace_entry      ent;
 223         int                     nr;
 224         unsigned long           ret;
 225 };
 226
 227
 228 /*
 229  * trace_flag_type is an enumeration that holds different
 230  * states when a trace occurs. These are:
 231  *  IRQS_OFF            - interrupts were disabled
 232  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 233  *  NEED_RESCED         - reschedule is requested
 234  *  HARDIRQ             - inside an interrupt handler
 235  *  SOFTIRQ             - inside a softirq handler
 236  */
 237 enum trace_flag_type {
 238         TRACE_FLAG_IRQS_OFF             = 0x01,
 239         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 240         TRACE_FLAG_NEED_RESCHED         = 0x04,
 241         TRACE_FLAG_HARDIRQ              = 0x08,
 242         TRACE_FLAG_SOFTIRQ              = 0x10,
 243 };
 244
 245 #define TRACE_BUF_SIZE          1024
 246
 247 /*
 248  * The CPU trace array - it consists of thousands of trace entries
 249  * plus some other descriptor data: (for example which task started
 250  * the trace, etc.)
 251  */
 252 struct trace_array_cpu {
 253         atomic_t                disabled;
 254         void                    *buffer_page;   /* ring buffer spare */
 255
 256         /* these fields get copied into max-trace: */
 257         unsigned long           trace_idx;
 258         unsigned long           overrun;
 259         unsigned long           saved_latency;
 260         unsigned long           critical_start;
 261         unsigned long           critical_end;
 262         unsigned long           critical_sequence;
 263         unsigned long           nice;
 264         unsigned long           policy;
 265         unsigned long           rt_priority;
 266         cycle_t                 preempt_timestamp;
 267         pid_t                   pid;
 268         uid_t                   uid;
 269         char                    comm[TASK_COMM_LEN];
 270 };
 271
 272 /*
 273  * The trace array - an array of per-CPU trace arrays. This is the
 274  * highest level data structure that individual tracers deal with.
 275  * They have on/off state as well:
 276  */
 277 struct trace_array {
 278         struct ring_buffer      *buffer;
 279         unsigned long           entries;
 280         int                     cpu;
 281         cycle_t                 time_start;
 282         struct task_struct      *waiter;
 283         struct trace_array_cpu  *data[NR_CPUS];
 284 };
 285
 286 #define FTRACE_CMP_TYPE(var, type) \
 287         __builtin_types_compatible_p(typeof(var), type *)
 288
 289 #undef IF_ASSIGN
 290 #define IF_ASSIGN(var, entry, etype, id)                \
 291         if (FTRACE_CMP_TYPE(var, etype)) {              \
 292                 var = (typeof(var))(entry);             \
 293                 WARN_ON(id && (entry)->type != id);     \
 294                 break;                                  \
 295         }
 296
 297 /* Will cause compile errors if type is not found. */
 298 extern void __ftrace_bad_type(void);
 299
 300 /*
 301  * The trace_assign_type is a verifier that the entry type is
 302  * the same as the type being assigned. To add new types simply
 303  * add a line with the following format:
 304  *
 305  * IF_ASSIGN(var, ent, type, id);
 306  *
 307  *  Where "type" is the trace type that includes the trace_entry
 308  *  as the "ent" item. And "id" is the trace identifier that is
 309  *  used in the trace_type enum.
 310  *
 311  *  If the type can have more than one id, then use zero.
 312  */
 313 #define trace_assign_type(var, ent)                                     \
 314         do {                                                            \
 315                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 316                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 317                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 318                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 319                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 320                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 321                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 322                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 323                           TRACE_MMIO_RW);                               \
 324                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 325                           TRACE_MMIO_MAP);                              \
 326                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 327                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 328                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 329                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 330                           TRACE_GRAPH_ENT);             \
 331                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 332                           TRACE_GRAPH_RET);             \
 333                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 334                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 335                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 336                           TRACE_KMEM_ALLOC);    \
 337                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 338                           TRACE_KMEM_FREE);     \
 339                 IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
 340                           TRACE_SYSCALL_ENTER);                         \
 341                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
 342                           TRACE_SYSCALL_EXIT);                          \
 343                 IF_ASSIGN(var, ent, struct trace_skb_event,             \
 344                           TRACE_SKB_SOURCE);                            \
 345                 __ftrace_bad_type();                                    \
 346         } while (0)
 347
 348 /*
 349  * An option specific to a tracer. This is a boolean value.
 350  * The bit is the bit index that sets its value on the
 351  * flags value in struct tracer_flags.
 352  */
 353 struct tracer_opt {
 354         const char      *name; /* Will appear on the trace_options file */
 355         u32             bit; /* Mask assigned in val field in tracer_flags */
 356 };
 357
 358 /*
 359  * The set of specific options for a tracer. Your tracer
 360  * have to set the initial value of the flags val.
 361  */
 362 struct tracer_flags {
 363         u32                     val;
 364         struct tracer_opt       *opts;
 365 };
 366
 367 /* Makes more easy to define a tracer opt */
 368 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 369
 370
 371 /**
 372  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 373  * @name: the name chosen to select it on the available_tracers file
 374  * @init: called when one switches to this tracer (echo name > current_tracer)
 375  * @reset: called when one switches to another tracer
 376  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 377  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 378  * @open: called when the trace file is opened
 379  * @pipe_open: called when the trace_pipe file is opened
 380  * @wait_pipe: override how the user waits for traces on trace_pipe
 381  * @close: called when the trace file is released
 382  * @read: override the default read callback on trace_pipe
 383  * @splice_read: override the default splice_read callback on trace_pipe
 384  * @selftest: selftest to run on boot (see trace_selftest.c)
 385  * @print_headers: override the first lines that describe your columns
 386  * @print_line: callback that prints a trace
 387  * @set_flag: signals one of your private flags changed (trace_options file)
 388  * @flags: your private flags
 389  */
 390 struct tracer {
 391         const char              *name;
 392         int                     (*init)(struct trace_array *tr);
 393         void                    (*reset)(struct trace_array *tr);
 394         void                    (*start)(struct trace_array *tr);
 395         void                    (*stop)(struct trace_array *tr);
 396         void                    (*open)(struct trace_iterator *iter);
 397         void                    (*pipe_open)(struct trace_iterator *iter);
 398         void                    (*wait_pipe)(struct trace_iterator *iter);
 399         void                    (*close)(struct trace_iterator *iter);
 400         ssize_t                 (*read)(struct trace_iterator *iter,
 401                                         struct file *filp, char __user *ubuf,
 402                                         size_t cnt, loff_t *ppos);
 403         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 404                                                struct file *filp,
 405                                                loff_t *ppos,
 406                                                struct pipe_inode_info *pipe,
 407                                                size_t len,
 408                                                unsigned int flags);
 409 #ifdef CONFIG_FTRACE_STARTUP_TEST
 410         int                     (*selftest)(struct tracer *trace,
 411                                             struct trace_array *tr);
 412 #endif
 413         void                    (*print_header)(struct seq_file *m);
 414         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 415         /* If you handled the flag setting, return 0 */
 416         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 417         struct tracer           *next;
 418         int                     print_max;
 419         struct tracer_flags     *flags;
 420         struct tracer_stat      *stats;
 421 };
 422
 423
 424 #define TRACE_PIPE_ALL_CPU      -1
 425
 426 int tracer_init(struct tracer *t, struct trace_array *tr);
 427 int tracing_is_enabled(void);
 428 void trace_wake_up(void);
 429 void tracing_reset(struct trace_array *tr, int cpu);
 430 void tracing_reset_online_cpus(struct trace_array *tr);
 431 void tracing_reset_current(int cpu);
 432 void tracing_reset_current_online_cpus(void);
 433 int tracing_open_generic(struct inode *inode, struct file *filp);
 434 struct dentry *trace_create_file(const char *name,
 435                                  mode_t mode,
 436                                  struct dentry *parent,
 437                                  void *data,
 438                                  const struct file_operations *fops);
 439
 440 struct dentry *tracing_init_dentry(void);
 441 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 442
 443 struct ring_buffer_event;
 444
 445 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
 446                                                     int type,
 447                                                     unsigned long len,
 448                                                     unsigned long flags,
 449                                                     int pc);
 450 void trace_buffer_unlock_commit(struct trace_array *tr,
 451                                 struct ring_buffer_event *event,
 452                                 unsigned long flags, int pc);
 453
 454 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 455                                                 struct trace_array_cpu *data);
 456
 457 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 458                                           int *ent_cpu, u64 *ent_ts);
 459
 460 void default_wait_pipe(struct trace_iterator *iter);
 461 void poll_wait_pipe(struct trace_iterator *iter);
 462
 463 void ftrace(struct trace_array *tr,
 464                             struct trace_array_cpu *data,
 465                             unsigned long ip,
 466                             unsigned long parent_ip,
 467                             unsigned long flags, int pc);
 468 void tracing_sched_switch_trace(struct trace_array *tr,
 469                                 struct task_struct *prev,
 470                                 struct task_struct *next,
 471                                 unsigned long flags, int pc);
 472
 473 void tracing_sched_wakeup_trace(struct trace_array *tr,
 474                                 struct task_struct *wakee,
 475                                 struct task_struct *cur,
 476                                 unsigned long flags, int pc);
 477 void trace_special(struct trace_array *tr,
 478                    struct trace_array_cpu *data,
 479                    unsigned long arg1,
 480                    unsigned long arg2,
 481                    unsigned long arg3, int pc);
 482 void trace_function(struct trace_array *tr,
 483                     unsigned long ip,
 484                     unsigned long parent_ip,
 485                     unsigned long flags, int pc);
 486
 487 void trace_graph_return(struct ftrace_graph_ret *trace);
 488 int trace_graph_entry(struct ftrace_graph_ent *trace);
 489
 490 void tracing_start_cmdline_record(void);
 491 void tracing_stop_cmdline_record(void);
 492 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 493 void tracing_stop_sched_switch_record(void);
 494 void tracing_start_sched_switch_record(void);
 495 int register_tracer(struct tracer *type);
 496 void unregister_tracer(struct tracer *type);
 497
 498 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 499
 500 extern unsigned long tracing_max_latency;
 501 extern unsigned long tracing_thresh;
 502
 503 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 504 void update_max_tr_single(struct trace_array *tr,
 505                           struct task_struct *tsk, int cpu);
 506
 507 void __trace_stack(struct trace_array *tr,
 508                    unsigned long flags,
 509                    int skip, int pc);
 510
 511 extern cycle_t ftrace_now(int cpu);
 512
 513 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 514 typedef void
 515 (*tracer_switch_func_t)(void *private,
 516                         void *__rq,
 517                         struct task_struct *prev,
 518                         struct task_struct *next);
 519
 520 struct tracer_switch_ops {
 521         tracer_switch_func_t            func;
 522         void                            *private;
 523         struct tracer_switch_ops        *next;
 524 };
 525 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 526
 527 extern void trace_find_cmdline(int pid, char comm[]);
 528
 529 #ifdef CONFIG_DYNAMIC_FTRACE
 530 extern unsigned long ftrace_update_tot_cnt;
 531 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 532 extern int DYN_FTRACE_TEST_NAME(void);
 533 #endif
 534
 535 #ifdef CONFIG_FTRACE_STARTUP_TEST
 536 extern int trace_selftest_startup_function(struct tracer *trace,
 537                                            struct trace_array *tr);
 538 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 539                                                  struct trace_array *tr);
 540 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 541                                           struct trace_array *tr);
 542 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 543                                              struct trace_array *tr);
 544 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 545                                                  struct trace_array *tr);
 546 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 547                                          struct trace_array *tr);
 548 extern int trace_selftest_startup_nop(struct tracer *trace,
 549                                          struct trace_array *tr);
 550 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 551                                                struct trace_array *tr);
 552 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 553                                                struct trace_array *tr);
 554 extern int trace_selftest_startup_branch(struct tracer *trace,
 555                                          struct trace_array *tr);
 556 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
 557                                               struct trace_array *tr);
 558 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 559
 560 extern void *head_page(struct trace_array_cpu *data);
 561 extern unsigned long long ns2usecs(cycle_t nsec);
 562 extern int
 563 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 564 extern int
 565 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 566
 567 extern unsigned long trace_flags;
 568
 569 /* Standard output formatting function used for function return traces */
 570 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 571 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 572 extern enum print_line_t
 573 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 574
 575 #ifdef CONFIG_DYNAMIC_FTRACE
 576 /* TODO: make this variable */
 577 #define FTRACE_GRAPH_MAX_FUNCS          32
 578 extern int ftrace_graph_count;
 579 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 580
 581 static inline int ftrace_graph_addr(unsigned long addr)
 582 {
 583         int i;
 584
 585         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 586                 return 1;
 587
 588         for (i = 0; i < ftrace_graph_count; i++) {
 589                 if (addr == ftrace_graph_funcs[i])
 590                         return 1;
 591         }
 592
 593         return 0;
 594 }
 595 #else
 596 static inline int ftrace_trace_addr(unsigned long addr)
 597 {
 598         return 1;
 599 }
 600 static inline int ftrace_graph_addr(unsigned long addr)
 601 {
 602         return 1;
 603 }
 604 #endif /* CONFIG_DYNAMIC_FTRACE */
 605 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 606 static inline enum print_line_t
 607 print_graph_function(struct trace_iterator *iter)
 608 {
 609         return TRACE_TYPE_UNHANDLED;
 610 }
 611 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 612
 613 extern struct pid *ftrace_pid_trace;
 614
 615 #ifdef CONFIG_FUNCTION_TRACER
 616 static inline int ftrace_trace_task(struct task_struct *task)
 617 {
 618         if (!ftrace_pid_trace)
 619                 return 1;
 620
 621         return test_tsk_trace_trace(task);
 622 }
 623 #else
 624 static inline int ftrace_trace_task(struct task_struct *task)
 625 {
 626         return 1;
 627 }
 628 #endif
 629
 630 /*
 631  * trace_iterator_flags is an enumeration that defines bit
 632  * positions into trace_flags that controls the output.
 633  *
 634  * NOTE: These bits must match the trace_options array in
 635  *       trace.c.
 636  */
 637 enum trace_iterator_flags {
 638         TRACE_ITER_PRINT_PARENT         = 0x01,
 639         TRACE_ITER_SYM_OFFSET           = 0x02,
 640         TRACE_ITER_SYM_ADDR             = 0x04,
 641         TRACE_ITER_VERBOSE              = 0x08,
 642         TRACE_ITER_RAW                  = 0x10,
 643         TRACE_ITER_HEX                  = 0x20,
 644         TRACE_ITER_BIN                  = 0x40,
 645         TRACE_ITER_BLOCK                = 0x80,
 646         TRACE_ITER_STACKTRACE           = 0x100,
 647         TRACE_ITER_SCHED_TREE           = 0x200,
 648         TRACE_ITER_PRINTK               = 0x400,
 649         TRACE_ITER_PREEMPTONLY          = 0x800,
 650         TRACE_ITER_BRANCH               = 0x1000,
 651         TRACE_ITER_ANNOTATE             = 0x2000,
 652         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 653         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 654         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 655         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 656         TRACE_ITER_LATENCY_FMT          = 0x40000,
 657         TRACE_ITER_GLOBAL_CLK           = 0x80000,
 658         TRACE_ITER_SLEEP_TIME           = 0x100000,
 659         TRACE_ITER_GRAPH_TIME           = 0x200000,
 660 };
 661
 662 /*
 663  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 664  * control the output of kernel symbols.
 665  */
 666 #define TRACE_ITER_SYM_MASK \
 667         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 668
 669 extern struct tracer nop_trace;
 670
 671 /**
 672  * ftrace_preempt_disable - disable preemption scheduler safe
 673  *
 674  * When tracing can happen inside the scheduler, there exists
 675  * cases that the tracing might happen before the need_resched
 676  * flag is checked. If this happens and the tracer calls
 677  * preempt_enable (after a disable), a schedule might take place
 678  * causing an infinite recursion.
 679  *
 680  * To prevent this, we read the need_resched flag before
 681  * disabling preemption. When we want to enable preemption we
 682  * check the flag, if it is set, then we call preempt_enable_no_resched.
 683  * Otherwise, we call preempt_enable.
 684  *
 685  * The rational for doing the above is that if need_resched is set
 686  * and we have yet to reschedule, we are either in an atomic location
 687  * (where we do not need to check for scheduling) or we are inside
 688  * the scheduler and do not want to resched.
 689  */
 690 static inline int ftrace_preempt_disable(void)
 691 {
 692         int resched;
 693
 694         resched = need_resched();
 695         preempt_disable_notrace();
 696
 697         return resched;
 698 }
 699
 700 /**
 701  * ftrace_preempt_enable - enable preemption scheduler safe
 702  * @resched: the return value from ftrace_preempt_disable
 703  *
 704  * This is a scheduler safe way to enable preemption and not miss
 705  * any preemption checks. The disabled saved the state of preemption.
 706  * If resched is set, then we are either inside an atomic or
 707  * are inside the scheduler (we would have already scheduled
 708  * otherwise). In this case, we do not want to call normal
 709  * preempt_enable, but preempt_enable_no_resched instead.
 710  */
 711 static inline void ftrace_preempt_enable(int resched)
 712 {
 713         if (resched)
 714                 preempt_enable_no_resched_notrace();
 715         else
 716                 preempt_enable_notrace();
 717 }
 718
 719 #ifdef CONFIG_BRANCH_TRACER
 720 extern int enable_branch_tracing(struct trace_array *tr);
 721 extern void disable_branch_tracing(void);
 722 static inline int trace_branch_enable(struct trace_array *tr)
 723 {
 724         if (trace_flags & TRACE_ITER_BRANCH)
 725                 return enable_branch_tracing(tr);
 726         return 0;
 727 }
 728 static inline void trace_branch_disable(void)
 729 {
 730         /* due to races, always disable */
 731         disable_branch_tracing();
 732 }
 733 #else
 734 static inline int trace_branch_enable(struct trace_array *tr)
 735 {
 736         return 0;
 737 }
 738 static inline void trace_branch_disable(void)
 739 {
 740 }
 741 #endif /* CONFIG_BRANCH_TRACER */
 742
 743 /* set ring buffers to default size if not already done so */
 744 int tracing_update_buffers(void);
 745
 746 /* trace event type bit fields, not numeric */
 747 enum {
 748         TRACE_EVENT_TYPE_PRINTF         = 1,
 749         TRACE_EVENT_TYPE_RAW            = 2,
 750 };
 751
 752 struct ftrace_event_field {
 753         struct list_head        link;
 754         char                    *name;
 755         char                    *type;
 756         int                     offset;
 757         int                     size;
 758         int                     is_signed;
 759 };
 760
 761 struct event_filter {
 762         int                     n_preds;
 763         struct filter_pred      **preds;
 764         char                    *filter_string;
 765 };
 766
 767 struct event_subsystem {
 768         struct list_head        list;
 769         const char              *name;
 770         struct dentry           *entry;
 771         void                    *filter;
 772 };
 773
 774 struct filter_pred;
 775
 776 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 777                                  int val1, int val2);
 778
 779 struct filter_pred {
 780         filter_pred_fn_t fn;
 781         u64 val;
 782         char str_val[MAX_FILTER_STR_VAL];
 783         int str_len;
 784         char *field_name;
 785         int offset;
 786         int not;
 787         int op;
 788         int pop_n;
 789 };
 790
 791 extern void print_event_filter(struct ftrace_event_call *call,
 792                                struct trace_seq *s);
 793 extern int apply_event_filter(struct ftrace_event_call *call,
 794                               char *filter_string);
 795 extern int apply_subsystem_event_filter(struct event_subsystem *system,
 796                                         char *filter_string);
 797 extern void print_subsystem_event_filter(struct event_subsystem *system,
 798                                          struct trace_seq *s);
 799
 800 static inline int
 801 filter_check_discard(struct ftrace_event_call *call, void *rec,
 802                      struct ring_buffer *buffer,
 803                      struct ring_buffer_event *event)
 804 {
 805         if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) {
 806                 ring_buffer_discard_commit(buffer, event);
 807                 return 1;
 808         }
 809
 810         return 0;
 811 }
 812
 813 #define DEFINE_COMPARISON_PRED(type)                                    \
 814 static int filter_pred_##type(struct filter_pred *pred, void *event,    \
 815                               int val1, int val2)                       \
 816 {                                                                       \
 817         type *addr = (type *)(event + pred->offset);                    \
 818         type val = (type)pred->val;                                     \
 819         int match = 0;                                                  \
 820                                                                         \
 821         switch (pred->op) {                                             \
 822         case OP_LT:                                                     \
 823                 match = (*addr < val);                                  \
 824                 break;                                                  \
 825         case OP_LE:                                                     \
 826                 match = (*addr <= val);                                 \
 827                 break;                                                  \
 828         case OP_GT:                                                     \
 829                 match = (*addr > val);                                  \
 830                 break;                                                  \
 831         case OP_GE:                                                     \
 832                 match = (*addr >= val);                                 \
 833                 break;                                                  \
 834         default:                                                        \
 835                 break;                                                  \
 836         }                                                               \
 837                                                                         \
 838         return match;                                                   \
 839 }
 840
 841 #define DEFINE_EQUALITY_PRED(size)                                      \
 842 static int filter_pred_##size(struct filter_pred *pred, void *event,    \
 843                               int val1, int val2)                       \
 844 {                                                                       \
 845         u##size *addr = (u##size *)(event + pred->offset);              \
 846         u##size val = (u##size)pred->val;                               \
 847         int match;                                                      \
 848                                                                         \
 849         match = (val == *addr) ^ pred->not;                             \
 850                                                                         \
 851         return match;                                                   \
 852 }
 853
 854 extern struct mutex event_mutex;
 855 extern struct list_head ftrace_events;
 856
 857 extern const char *__start___trace_bprintk_fmt[];
 858 extern const char *__stop___trace_bprintk_fmt[];
 859
 860 #undef TRACE_EVENT_FORMAT
 861 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
 862         extern struct ftrace_event_call event_##call;
 863 #undef TRACE_EVENT_FORMAT_NOFILTER
 864 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt)
 865 #include "trace_event_types.h"
 866
 867 #endif /* _LINUX_KERNEL_TRACE_H */