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 <trace/kmemtrace.h>
  13 #include <trace/power.h>
  14
  15 enum trace_type {
  16         __TRACE_FIRST_TYPE = 0,
  17
  18         TRACE_FN,
  19         TRACE_CTX,
  20         TRACE_WAKE,
  21         TRACE_STACK,
  22         TRACE_PRINT,
  23         TRACE_BPRINT,
  24         TRACE_SPECIAL,
  25         TRACE_MMIO_RW,
  26         TRACE_MMIO_MAP,
  27         TRACE_BRANCH,
  28         TRACE_BOOT_CALL,
  29         TRACE_BOOT_RET,
  30         TRACE_GRAPH_RET,
  31         TRACE_GRAPH_ENT,
  32         TRACE_USER_STACK,
  33         TRACE_HW_BRANCHES,
  34         TRACE_SYSCALL_ENTER,
  35         TRACE_SYSCALL_EXIT,
  36         TRACE_KMEM_ALLOC,
  37         TRACE_KMEM_FREE,
  38         TRACE_POWER,
  39         TRACE_BLK,
  40
  41         __TRACE_LAST_TYPE,
  42 };
  43
  44 /*
  45  * The trace entry - the most basic unit of tracing. This is what
  46  * is printed in the end as a single line in the trace output, such as:
  47  *
  48  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  49  */
  50 struct trace_entry {
  51         unsigned char           type;
  52         unsigned char           flags;
  53         unsigned char           preempt_count;
  54         int                     pid;
  55         int                     tgid;
  56 };
  57
  58 /*
  59  * Function trace entry - function address and parent function addres:
  60  */
  61 struct ftrace_entry {
  62         struct trace_entry      ent;
  63         unsigned long           ip;
  64         unsigned long           parent_ip;
  65 };
  66
  67 /* Function call entry */
  68 struct ftrace_graph_ent_entry {
  69         struct trace_entry              ent;
  70         struct ftrace_graph_ent         graph_ent;
  71 };
  72
  73 /* Function return entry */
  74 struct ftrace_graph_ret_entry {
  75         struct trace_entry              ent;
  76         struct ftrace_graph_ret         ret;
  77 };
  78 extern struct tracer boot_tracer;
  79
  80 /*
  81  * Context switch trace entry - which task (and prio) we switched from/to:
  82  */
  83 struct ctx_switch_entry {
  84         struct trace_entry      ent;
  85         unsigned int            prev_pid;
  86         unsigned char           prev_prio;
  87         unsigned char           prev_state;
  88         unsigned int            next_pid;
  89         unsigned char           next_prio;
  90         unsigned char           next_state;
  91         unsigned int            next_cpu;
  92 };
  93
  94 /*
  95  * Special (free-form) trace entry:
  96  */
  97 struct special_entry {
  98         struct trace_entry      ent;
  99         unsigned long           arg1;
 100         unsigned long           arg2;
 101         unsigned long           arg3;
 102 };
 103
 104 /*
 105  * Stack-trace entry:
 106  */
 107
 108 #define FTRACE_STACK_ENTRIES    8
 109
 110 struct stack_entry {
 111         struct trace_entry      ent;
 112         unsigned long           caller[FTRACE_STACK_ENTRIES];
 113 };
 114
 115 struct userstack_entry {
 116         struct trace_entry      ent;
 117         unsigned long           caller[FTRACE_STACK_ENTRIES];
 118 };
 119
 120 /*
 121  * trace_printk entry:
 122  */
 123 struct bprint_entry {
 124         struct trace_entry      ent;
 125         unsigned long           ip;
 126         const char              *fmt;
 127         u32                     buf[];
 128 };
 129
 130 struct print_entry {
 131         struct trace_entry      ent;
 132         unsigned long           ip;
 133         char                    buf[];
 134 };
 135
 136 #define TRACE_OLD_SIZE          88
 137
 138 struct trace_field_cont {
 139         unsigned char           type;
 140         /* Temporary till we get rid of this completely */
 141         char                    buf[TRACE_OLD_SIZE - 1];
 142 };
 143
 144 struct trace_mmiotrace_rw {
 145         struct trace_entry      ent;
 146         struct mmiotrace_rw     rw;
 147 };
 148
 149 struct trace_mmiotrace_map {
 150         struct trace_entry      ent;
 151         struct mmiotrace_map    map;
 152 };
 153
 154 struct trace_boot_call {
 155         struct trace_entry      ent;
 156         struct boot_trace_call boot_call;
 157 };
 158
 159 struct trace_boot_ret {
 160         struct trace_entry      ent;
 161         struct boot_trace_ret boot_ret;
 162 };
 163
 164 #define TRACE_FUNC_SIZE 30
 165 #define TRACE_FILE_SIZE 20
 166 struct trace_branch {
 167         struct trace_entry      ent;
 168         unsigned                line;
 169         char                    func[TRACE_FUNC_SIZE+1];
 170         char                    file[TRACE_FILE_SIZE+1];
 171         char                    correct;
 172 };
 173
 174 struct hw_branch_entry {
 175         struct trace_entry      ent;
 176         u64                     from;
 177         u64                     to;
 178 };
 179
 180 struct trace_power {
 181         struct trace_entry      ent;
 182         struct power_trace      state_data;
 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
 216 /*
 217  * trace_flag_type is an enumeration that holds different
 218  * states when a trace occurs. These are:
 219  *  IRQS_OFF            - interrupts were disabled
 220  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 221  *  NEED_RESCED         - reschedule is requested
 222  *  HARDIRQ             - inside an interrupt handler
 223  *  SOFTIRQ             - inside a softirq handler
 224  */
 225 enum trace_flag_type {
 226         TRACE_FLAG_IRQS_OFF             = 0x01,
 227         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 228         TRACE_FLAG_NEED_RESCHED         = 0x04,
 229         TRACE_FLAG_HARDIRQ              = 0x08,
 230         TRACE_FLAG_SOFTIRQ              = 0x10,
 231 };
 232
 233 #define TRACE_BUF_SIZE          1024
 234
 235 /*
 236  * The CPU trace array - it consists of thousands of trace entries
 237  * plus some other descriptor data: (for example which task started
 238  * the trace, etc.)
 239  */
 240 struct trace_array_cpu {
 241         atomic_t                disabled;
 242         void                    *buffer_page;   /* ring buffer spare */
 243
 244         /* these fields get copied into max-trace: */
 245         unsigned long           trace_idx;
 246         unsigned long           overrun;
 247         unsigned long           saved_latency;
 248         unsigned long           critical_start;
 249         unsigned long           critical_end;
 250         unsigned long           critical_sequence;
 251         unsigned long           nice;
 252         unsigned long           policy;
 253         unsigned long           rt_priority;
 254         cycle_t                 preempt_timestamp;
 255         pid_t                   pid;
 256         uid_t                   uid;
 257         char                    comm[TASK_COMM_LEN];
 258 };
 259
 260 struct trace_iterator;
 261
 262 /*
 263  * The trace array - an array of per-CPU trace arrays. This is the
 264  * highest level data structure that individual tracers deal with.
 265  * They have on/off state as well:
 266  */
 267 struct trace_array {
 268         struct ring_buffer      *buffer;
 269         unsigned long           entries;
 270         int                     cpu;
 271         cycle_t                 time_start;
 272         struct task_struct      *waiter;
 273         struct trace_array_cpu  *data[NR_CPUS];
 274 };
 275
 276 #define FTRACE_CMP_TYPE(var, type) \
 277         __builtin_types_compatible_p(typeof(var), type *)
 278
 279 #undef IF_ASSIGN
 280 #define IF_ASSIGN(var, entry, etype, id)                \
 281         if (FTRACE_CMP_TYPE(var, etype)) {              \
 282                 var = (typeof(var))(entry);             \
 283                 WARN_ON(id && (entry)->type != id);     \
 284                 break;                                  \
 285         }
 286
 287 /* Will cause compile errors if type is not found. */
 288 extern void __ftrace_bad_type(void);
 289
 290 /*
 291  * The trace_assign_type is a verifier that the entry type is
 292  * the same as the type being assigned. To add new types simply
 293  * add a line with the following format:
 294  *
 295  * IF_ASSIGN(var, ent, type, id);
 296  *
 297  *  Where "type" is the trace type that includes the trace_entry
 298  *  as the "ent" item. And "id" is the trace identifier that is
 299  *  used in the trace_type enum.
 300  *
 301  *  If the type can have more than one id, then use zero.
 302  */
 303 #define trace_assign_type(var, ent)                                     \
 304         do {                                                            \
 305                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 306                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 307                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 308                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 309                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 310                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 311                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 312                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 313                           TRACE_MMIO_RW);                               \
 314                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 315                           TRACE_MMIO_MAP);                              \
 316                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 317                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 318                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 319                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 320                           TRACE_GRAPH_ENT);             \
 321                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 322                           TRACE_GRAPH_RET);             \
 323                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 324                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 325                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 326                           TRACE_KMEM_ALLOC);    \
 327                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 328                           TRACE_KMEM_FREE);     \
 329                 IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
 330                           TRACE_SYSCALL_ENTER);                         \
 331                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
 332                           TRACE_SYSCALL_EXIT);                          \
 333                 __ftrace_bad_type();                                    \
 334         } while (0)
 335
 336 /* Return values for print_line callback */
 337 enum print_line_t {
 338         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 339         TRACE_TYPE_HANDLED      = 1,
 340         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 341         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 342 };
 343
 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 struct trace_seq {
 421         unsigned char           buffer[PAGE_SIZE];
 422         unsigned int            len;
 423         unsigned int            readpos;
 424 };
 425
 426 static inline void
 427 trace_seq_init(struct trace_seq *s)
 428 {
 429         s->len = 0;
 430         s->readpos = 0;
 431 }
 432
 433
 434 #define TRACE_PIPE_ALL_CPU      -1
 435
 436 /*
 437  * Trace iterator - used by printout routines who present trace
 438  * results to users and which routines might sleep, etc:
 439  */
 440 struct trace_iterator {
 441         struct trace_array      *tr;
 442         struct tracer           *trace;
 443         void                    *private;
 444         int                     cpu_file;
 445         struct mutex            mutex;
 446         struct ring_buffer_iter *buffer_iter[NR_CPUS];
 447
 448         /* The below is zeroed out in pipe_read */
 449         struct trace_seq        seq;
 450         struct trace_entry      *ent;
 451         int                     cpu;
 452         u64                     ts;
 453
 454         unsigned long           iter_flags;
 455         loff_t                  pos;
 456         long                    idx;
 457
 458         cpumask_var_t           started;
 459 };
 460
 461 int tracer_init(struct tracer *t, struct trace_array *tr);
 462 int tracing_is_enabled(void);
 463 void trace_wake_up(void);
 464 void tracing_reset(struct trace_array *tr, int cpu);
 465 void tracing_reset_online_cpus(struct trace_array *tr);
 466 int tracing_open_generic(struct inode *inode, struct file *filp);
 467 struct dentry *tracing_init_dentry(void);
 468 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 469
 470 struct ring_buffer_event;
 471
 472 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
 473                                                     unsigned char type,
 474                                                     unsigned long len,
 475                                                     unsigned long flags,
 476                                                     int pc);
 477 void trace_buffer_unlock_commit(struct trace_array *tr,
 478                                 struct ring_buffer_event *event,
 479                                 unsigned long flags, int pc);
 480
 481 struct ring_buffer_event *
 482 trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
 483                                   unsigned long flags, int pc);
 484 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
 485                                         unsigned long flags, int pc);
 486
 487 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 488                                                 struct trace_array_cpu *data);
 489
 490 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 491                                           int *ent_cpu, u64 *ent_ts);
 492
 493 void tracing_generic_entry_update(struct trace_entry *entry,
 494                                   unsigned long flags,
 495                                   int pc);
 496
 497 void default_wait_pipe(struct trace_iterator *iter);
 498 void poll_wait_pipe(struct trace_iterator *iter);
 499
 500 void ftrace(struct trace_array *tr,
 501                             struct trace_array_cpu *data,
 502                             unsigned long ip,
 503                             unsigned long parent_ip,
 504                             unsigned long flags, int pc);
 505 void tracing_sched_switch_trace(struct trace_array *tr,
 506                                 struct task_struct *prev,
 507                                 struct task_struct *next,
 508                                 unsigned long flags, int pc);
 509 void tracing_record_cmdline(struct task_struct *tsk);
 510
 511 void tracing_sched_wakeup_trace(struct trace_array *tr,
 512                                 struct task_struct *wakee,
 513                                 struct task_struct *cur,
 514                                 unsigned long flags, int pc);
 515 void trace_special(struct trace_array *tr,
 516                    struct trace_array_cpu *data,
 517                    unsigned long arg1,
 518                    unsigned long arg2,
 519                    unsigned long arg3, int pc);
 520 void trace_function(struct trace_array *tr,
 521                     unsigned long ip,
 522                     unsigned long parent_ip,
 523                     unsigned long flags, int pc);
 524
 525 void trace_graph_return(struct ftrace_graph_ret *trace);
 526 int trace_graph_entry(struct ftrace_graph_ent *trace);
 527
 528 void tracing_start_cmdline_record(void);
 529 void tracing_stop_cmdline_record(void);
 530 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 531 void tracing_stop_sched_switch_record(void);
 532 void tracing_start_sched_switch_record(void);
 533 int register_tracer(struct tracer *type);
 534 void unregister_tracer(struct tracer *type);
 535
 536 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 537
 538 extern unsigned long tracing_max_latency;
 539 extern unsigned long tracing_thresh;
 540
 541 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 542 void update_max_tr_single(struct trace_array *tr,
 543                           struct task_struct *tsk, int cpu);
 544
 545 void __trace_stack(struct trace_array *tr,
 546                    unsigned long flags,
 547                    int skip, int pc);
 548
 549 extern cycle_t ftrace_now(int cpu);
 550
 551 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 552 typedef void
 553 (*tracer_switch_func_t)(void *private,
 554                         void *__rq,
 555                         struct task_struct *prev,
 556                         struct task_struct *next);
 557
 558 struct tracer_switch_ops {
 559         tracer_switch_func_t            func;
 560         void                            *private;
 561         struct tracer_switch_ops        *next;
 562 };
 563 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 564
 565 extern void trace_find_cmdline(int pid, char comm[]);
 566
 567 #ifdef CONFIG_DYNAMIC_FTRACE
 568 extern unsigned long ftrace_update_tot_cnt;
 569 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 570 extern int DYN_FTRACE_TEST_NAME(void);
 571 #endif
 572
 573 #ifdef CONFIG_FTRACE_STARTUP_TEST
 574 extern int trace_selftest_startup_function(struct tracer *trace,
 575                                            struct trace_array *tr);
 576 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 577                                                  struct trace_array *tr);
 578 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 579                                           struct trace_array *tr);
 580 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 581                                              struct trace_array *tr);
 582 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 583                                                  struct trace_array *tr);
 584 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 585                                          struct trace_array *tr);
 586 extern int trace_selftest_startup_nop(struct tracer *trace,
 587                                          struct trace_array *tr);
 588 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 589                                                struct trace_array *tr);
 590 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 591                                                struct trace_array *tr);
 592 extern int trace_selftest_startup_branch(struct tracer *trace,
 593                                          struct trace_array *tr);
 594 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 595
 596 extern void *head_page(struct trace_array_cpu *data);
 597 extern long ns2usecs(cycle_t nsec);
 598 extern int
 599 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 600 extern int
 601 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 602
 603 extern unsigned long trace_flags;
 604
 605 /* Standard output formatting function used for function return traces */
 606 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 607 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 608
 609 #ifdef CONFIG_DYNAMIC_FTRACE
 610 /* TODO: make this variable */
 611 #define FTRACE_GRAPH_MAX_FUNCS          32
 612 extern int ftrace_graph_count;
 613 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 614
 615 static inline int ftrace_graph_addr(unsigned long addr)
 616 {
 617         int i;
 618
 619         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 620                 return 1;
 621
 622         for (i = 0; i < ftrace_graph_count; i++) {
 623                 if (addr == ftrace_graph_funcs[i])
 624                         return 1;
 625         }
 626
 627         return 0;
 628 }
 629 #else
 630 static inline int ftrace_trace_addr(unsigned long addr)
 631 {
 632         return 1;
 633 }
 634 static inline int ftrace_graph_addr(unsigned long addr)
 635 {
 636         return 1;
 637 }
 638 #endif /* CONFIG_DYNAMIC_FTRACE */
 639
 640 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 641 static inline enum print_line_t
 642 print_graph_function(struct trace_iterator *iter)
 643 {
 644         return TRACE_TYPE_UNHANDLED;
 645 }
 646 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 647
 648 extern struct pid *ftrace_pid_trace;
 649
 650 static inline int ftrace_trace_task(struct task_struct *task)
 651 {
 652         if (!ftrace_pid_trace)
 653                 return 1;
 654
 655         return test_tsk_trace_trace(task);
 656 }
 657
 658 /*
 659  * trace_iterator_flags is an enumeration that defines bit
 660  * positions into trace_flags that controls the output.
 661  *
 662  * NOTE: These bits must match the trace_options array in
 663  *       trace.c.
 664  */
 665 enum trace_iterator_flags {
 666         TRACE_ITER_PRINT_PARENT         = 0x01,
 667         TRACE_ITER_SYM_OFFSET           = 0x02,
 668         TRACE_ITER_SYM_ADDR             = 0x04,
 669         TRACE_ITER_VERBOSE              = 0x08,
 670         TRACE_ITER_RAW                  = 0x10,
 671         TRACE_ITER_HEX                  = 0x20,
 672         TRACE_ITER_BIN                  = 0x40,
 673         TRACE_ITER_BLOCK                = 0x80,
 674         TRACE_ITER_STACKTRACE           = 0x100,
 675         TRACE_ITER_SCHED_TREE           = 0x200,
 676         TRACE_ITER_PRINTK               = 0x400,
 677         TRACE_ITER_PREEMPTONLY          = 0x800,
 678         TRACE_ITER_BRANCH               = 0x1000,
 679         TRACE_ITER_ANNOTATE             = 0x2000,
 680         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 681         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 682         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 683         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 684         TRACE_ITER_LATENCY_FMT          = 0x40000,
 685         TRACE_ITER_GLOBAL_CLK           = 0x80000,
 686 };
 687
 688 /*
 689  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 690  * control the output of kernel symbols.
 691  */
 692 #define TRACE_ITER_SYM_MASK \
 693         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 694
 695 extern struct tracer nop_trace;
 696
 697 /**
 698  * ftrace_preempt_disable - disable preemption scheduler safe
 699  *
 700  * When tracing can happen inside the scheduler, there exists
 701  * cases that the tracing might happen before the need_resched
 702  * flag is checked. If this happens and the tracer calls
 703  * preempt_enable (after a disable), a schedule might take place
 704  * causing an infinite recursion.
 705  *
 706  * To prevent this, we read the need_resched flag before
 707  * disabling preemption. When we want to enable preemption we
 708  * check the flag, if it is set, then we call preempt_enable_no_resched.
 709  * Otherwise, we call preempt_enable.
 710  *
 711  * The rational for doing the above is that if need_resched is set
 712  * and we have yet to reschedule, we are either in an atomic location
 713  * (where we do not need to check for scheduling) or we are inside
 714  * the scheduler and do not want to resched.
 715  */
 716 static inline int ftrace_preempt_disable(void)
 717 {
 718         int resched;
 719
 720         resched = need_resched();
 721         preempt_disable_notrace();
 722
 723         return resched;
 724 }
 725
 726 /**
 727  * ftrace_preempt_enable - enable preemption scheduler safe
 728  * @resched: the return value from ftrace_preempt_disable
 729  *
 730  * This is a scheduler safe way to enable preemption and not miss
 731  * any preemption checks. The disabled saved the state of preemption.
 732  * If resched is set, then we are either inside an atomic or
 733  * are inside the scheduler (we would have already scheduled
 734  * otherwise). In this case, we do not want to call normal
 735  * preempt_enable, but preempt_enable_no_resched instead.
 736  */
 737 static inline void ftrace_preempt_enable(int resched)
 738 {
 739         if (resched)
 740                 preempt_enable_no_resched_notrace();
 741         else
 742                 preempt_enable_notrace();
 743 }
 744
 745 #ifdef CONFIG_BRANCH_TRACER
 746 extern int enable_branch_tracing(struct trace_array *tr);
 747 extern void disable_branch_tracing(void);
 748 static inline int trace_branch_enable(struct trace_array *tr)
 749 {
 750         if (trace_flags & TRACE_ITER_BRANCH)
 751                 return enable_branch_tracing(tr);
 752         return 0;
 753 }
 754 static inline void trace_branch_disable(void)
 755 {
 756         /* due to races, always disable */
 757         disable_branch_tracing();
 758 }
 759 #else
 760 static inline int trace_branch_enable(struct trace_array *tr)
 761 {
 762         return 0;
 763 }
 764 static inline void trace_branch_disable(void)
 765 {
 766 }
 767 #endif /* CONFIG_BRANCH_TRACER */
 768
 769 /* set ring buffers to default size if not already done so */
 770 int tracing_update_buffers(void);
 771
 772 /* trace event type bit fields, not numeric */
 773 enum {
 774         TRACE_EVENT_TYPE_PRINTF         = 1,
 775         TRACE_EVENT_TYPE_RAW            = 2,
 776 };
 777
 778 struct ftrace_event_call {
 779         char            *name;
 780         char            *system;
 781         struct dentry   *dir;
 782         int             enabled;
 783         int             (*regfunc)(void);
 784         void            (*unregfunc)(void);
 785         int             id;
 786         int             (*raw_init)(void);
 787         int             (*show_format)(struct trace_seq *s);
 788
 789 #ifdef CONFIG_EVENT_PROFILE
 790         atomic_t        profile_count;
 791         int             (*profile_enable)(struct ftrace_event_call *);
 792         void            (*profile_disable)(struct ftrace_event_call *);
 793 #endif
 794 };
 795
 796 void event_trace_printk(unsigned long ip, const char *fmt, ...);
 797 extern struct ftrace_event_call __start_ftrace_events[];
 798 extern struct ftrace_event_call __stop_ftrace_events[];
 799
 800 #define for_each_event(event)                                           \
 801         for (event = __start_ftrace_events;                             \
 802              (unsigned long)event < (unsigned long)__stop_ftrace_events; \
 803              event++)
 804
 805 extern const char *__start___trace_bprintk_fmt[];
 806 extern const char *__stop___trace_bprintk_fmt[];
 807
 808 /*
 809  * The double __builtin_constant_p is because gcc will give us an error
 810  * if we try to allocate the static variable to fmt if it is not a
 811  * constant. Even with the outer if statement optimizing out.
 812  */
 813 #define event_trace_printk(ip, fmt, args...)                            \
 814 do {                                                                    \
 815         __trace_printk_check_format(fmt, ##args);                       \
 816         tracing_record_cmdline(current);                                \
 817         if (__builtin_constant_p(fmt)) {                                \
 818                 static const char *trace_printk_fmt                     \
 819                   __attribute__((section("__trace_printk_fmt"))) =      \
 820                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 821                                                                         \
 822                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 823         } else                                                          \
 824                 __trace_printk(ip, fmt, ##args);                        \
 825 } while (0)
 826
 827 #endif /* _LINUX_KERNEL_TRACE_H */