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         int                     depth;
 127         const char              *fmt;
 128         u32                     buf[];
 129 };
 130
 131 struct print_entry {
 132         struct trace_entry      ent;
 133         unsigned long           ip;
 134         int                     depth;
 135         char                    buf[];
 136 };
 137
 138 #define TRACE_OLD_SIZE          88
 139
 140 struct trace_field_cont {
 141         unsigned char           type;
 142         /* Temporary till we get rid of this completely */
 143         char                    buf[TRACE_OLD_SIZE - 1];
 144 };
 145
 146 struct trace_mmiotrace_rw {
 147         struct trace_entry      ent;
 148         struct mmiotrace_rw     rw;
 149 };
 150
 151 struct trace_mmiotrace_map {
 152         struct trace_entry      ent;
 153         struct mmiotrace_map    map;
 154 };
 155
 156 struct trace_boot_call {
 157         struct trace_entry      ent;
 158         struct boot_trace_call boot_call;
 159 };
 160
 161 struct trace_boot_ret {
 162         struct trace_entry      ent;
 163         struct boot_trace_ret boot_ret;
 164 };
 165
 166 #define TRACE_FUNC_SIZE 30
 167 #define TRACE_FILE_SIZE 20
 168 struct trace_branch {
 169         struct trace_entry      ent;
 170         unsigned                line;
 171         char                    func[TRACE_FUNC_SIZE+1];
 172         char                    file[TRACE_FILE_SIZE+1];
 173         char                    correct;
 174 };
 175
 176 struct hw_branch_entry {
 177         struct trace_entry      ent;
 178         u64                     from;
 179         u64                     to;
 180 };
 181
 182 struct trace_power {
 183         struct trace_entry      ent;
 184         struct power_trace      state_data;
 185 };
 186
 187 struct kmemtrace_alloc_entry {
 188         struct trace_entry      ent;
 189         enum kmemtrace_type_id type_id;
 190         unsigned long call_site;
 191         const void *ptr;
 192         size_t bytes_req;
 193         size_t bytes_alloc;
 194         gfp_t gfp_flags;
 195         int node;
 196 };
 197
 198 struct kmemtrace_free_entry {
 199         struct trace_entry      ent;
 200         enum kmemtrace_type_id type_id;
 201         unsigned long call_site;
 202         const void *ptr;
 203 };
 204
 205 struct syscall_trace_enter {
 206         struct trace_entry      ent;
 207         int                     nr;
 208         unsigned long           args[];
 209 };
 210
 211 struct syscall_trace_exit {
 212         struct trace_entry      ent;
 213         int                     nr;
 214         unsigned long           ret;
 215 };
 216
 217
 218 /*
 219  * trace_flag_type is an enumeration that holds different
 220  * states when a trace occurs. These are:
 221  *  IRQS_OFF            - interrupts were disabled
 222  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 223  *  NEED_RESCED         - reschedule is requested
 224  *  HARDIRQ             - inside an interrupt handler
 225  *  SOFTIRQ             - inside a softirq handler
 226  */
 227 enum trace_flag_type {
 228         TRACE_FLAG_IRQS_OFF             = 0x01,
 229         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 230         TRACE_FLAG_NEED_RESCHED         = 0x04,
 231         TRACE_FLAG_HARDIRQ              = 0x08,
 232         TRACE_FLAG_SOFTIRQ              = 0x10,
 233 };
 234
 235 #define TRACE_BUF_SIZE          1024
 236
 237 /*
 238  * The CPU trace array - it consists of thousands of trace entries
 239  * plus some other descriptor data: (for example which task started
 240  * the trace, etc.)
 241  */
 242 struct trace_array_cpu {
 243         atomic_t                disabled;
 244         void                    *buffer_page;   /* ring buffer spare */
 245
 246         /* these fields get copied into max-trace: */
 247         unsigned long           trace_idx;
 248         unsigned long           overrun;
 249         unsigned long           saved_latency;
 250         unsigned long           critical_start;
 251         unsigned long           critical_end;
 252         unsigned long           critical_sequence;
 253         unsigned long           nice;
 254         unsigned long           policy;
 255         unsigned long           rt_priority;
 256         cycle_t                 preempt_timestamp;
 257         pid_t                   pid;
 258         uid_t                   uid;
 259         char                    comm[TASK_COMM_LEN];
 260 };
 261
 262 struct trace_iterator;
 263
 264 /*
 265  * The trace array - an array of per-CPU trace arrays. This is the
 266  * highest level data structure that individual tracers deal with.
 267  * They have on/off state as well:
 268  */
 269 struct trace_array {
 270         struct ring_buffer      *buffer;
 271         unsigned long           entries;
 272         int                     cpu;
 273         cycle_t                 time_start;
 274         struct task_struct      *waiter;
 275         struct trace_array_cpu  *data[NR_CPUS];
 276 };
 277
 278 #define FTRACE_CMP_TYPE(var, type) \
 279         __builtin_types_compatible_p(typeof(var), type *)
 280
 281 #undef IF_ASSIGN
 282 #define IF_ASSIGN(var, entry, etype, id)                \
 283         if (FTRACE_CMP_TYPE(var, etype)) {              \
 284                 var = (typeof(var))(entry);             \
 285                 WARN_ON(id && (entry)->type != id);     \
 286                 break;                                  \
 287         }
 288
 289 /* Will cause compile errors if type is not found. */
 290 extern void __ftrace_bad_type(void);
 291
 292 /*
 293  * The trace_assign_type is a verifier that the entry type is
 294  * the same as the type being assigned. To add new types simply
 295  * add a line with the following format:
 296  *
 297  * IF_ASSIGN(var, ent, type, id);
 298  *
 299  *  Where "type" is the trace type that includes the trace_entry
 300  *  as the "ent" item. And "id" is the trace identifier that is
 301  *  used in the trace_type enum.
 302  *
 303  *  If the type can have more than one id, then use zero.
 304  */
 305 #define trace_assign_type(var, ent)                                     \
 306         do {                                                            \
 307                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 308                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 309                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 310                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 311                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 312                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 313                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 314                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 315                           TRACE_MMIO_RW);                               \
 316                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 317                           TRACE_MMIO_MAP);                              \
 318                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 319                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 320                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 321                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 322                           TRACE_GRAPH_ENT);             \
 323                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 324                           TRACE_GRAPH_RET);             \
 325                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 326                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 327                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 328                           TRACE_KMEM_ALLOC);    \
 329                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 330                           TRACE_KMEM_FREE);     \
 331                 IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
 332                           TRACE_SYSCALL_ENTER);                         \
 333                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
 334                           TRACE_SYSCALL_EXIT);                          \
 335                 __ftrace_bad_type();                                    \
 336         } while (0)
 337
 338 /* Return values for print_line callback */
 339 enum print_line_t {
 340         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 341         TRACE_TYPE_HANDLED      = 1,
 342         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 343         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 344 };
 345
 346
 347 /*
 348  * An option specific to a tracer. This is a boolean value.
 349  * The bit is the bit index that sets its value on the
 350  * flags value in struct tracer_flags.
 351  */
 352 struct tracer_opt {
 353         const char      *name; /* Will appear on the trace_options file */
 354         u32             bit; /* Mask assigned in val field in tracer_flags */
 355 };
 356
 357 /*
 358  * The set of specific options for a tracer. Your tracer
 359  * have to set the initial value of the flags val.
 360  */
 361 struct tracer_flags {
 362         u32                     val;
 363         struct tracer_opt       *opts;
 364 };
 365
 366 /* Makes more easy to define a tracer opt */
 367 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 368
 369
 370 /**
 371  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 372  * @name: the name chosen to select it on the available_tracers file
 373  * @init: called when one switches to this tracer (echo name > current_tracer)
 374  * @reset: called when one switches to another tracer
 375  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 376  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 377  * @open: called when the trace file is opened
 378  * @pipe_open: called when the trace_pipe file is opened
 379  * @wait_pipe: override how the user waits for traces on trace_pipe
 380  * @close: called when the trace file is released
 381  * @read: override the default read callback on trace_pipe
 382  * @splice_read: override the default splice_read callback on trace_pipe
 383  * @selftest: selftest to run on boot (see trace_selftest.c)
 384  * @print_headers: override the first lines that describe your columns
 385  * @print_line: callback that prints a trace
 386  * @set_flag: signals one of your private flags changed (trace_options file)
 387  * @flags: your private flags
 388  */
 389 struct tracer {
 390         const char              *name;
 391         int                     (*init)(struct trace_array *tr);
 392         void                    (*reset)(struct trace_array *tr);
 393         void                    (*start)(struct trace_array *tr);
 394         void                    (*stop)(struct trace_array *tr);
 395         void                    (*open)(struct trace_iterator *iter);
 396         void                    (*pipe_open)(struct trace_iterator *iter);
 397         void                    (*wait_pipe)(struct trace_iterator *iter);
 398         void                    (*close)(struct trace_iterator *iter);
 399         ssize_t                 (*read)(struct trace_iterator *iter,
 400                                         struct file *filp, char __user *ubuf,
 401                                         size_t cnt, loff_t *ppos);
 402         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 403                                                struct file *filp,
 404                                                loff_t *ppos,
 405                                                struct pipe_inode_info *pipe,
 406                                                size_t len,
 407                                                unsigned int flags);
 408 #ifdef CONFIG_FTRACE_STARTUP_TEST
 409         int                     (*selftest)(struct tracer *trace,
 410                                             struct trace_array *tr);
 411 #endif
 412         void                    (*print_header)(struct seq_file *m);
 413         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 414         /* If you handled the flag setting, return 0 */
 415         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 416         struct tracer           *next;
 417         int                     print_max;
 418         struct tracer_flags     *flags;
 419         struct tracer_stat      *stats;
 420 };
 421
 422 struct trace_seq {
 423         unsigned char           buffer[PAGE_SIZE];
 424         unsigned int            len;
 425         unsigned int            readpos;
 426 };
 427
 428 static inline void
 429 trace_seq_init(struct trace_seq *s)
 430 {
 431         s->len = 0;
 432         s->readpos = 0;
 433 }
 434
 435
 436 #define TRACE_PIPE_ALL_CPU      -1
 437
 438 /*
 439  * Trace iterator - used by printout routines who present trace
 440  * results to users and which routines might sleep, etc:
 441  */
 442 struct trace_iterator {
 443         struct trace_array      *tr;
 444         struct tracer           *trace;
 445         void                    *private;
 446         int                     cpu_file;
 447         struct mutex            mutex;
 448         struct ring_buffer_iter *buffer_iter[NR_CPUS];
 449
 450         /* The below is zeroed out in pipe_read */
 451         struct trace_seq        seq;
 452         struct trace_entry      *ent;
 453         int                     cpu;
 454         u64                     ts;
 455
 456         unsigned long           iter_flags;
 457         loff_t                  pos;
 458         long                    idx;
 459
 460         cpumask_var_t           started;
 461 };
 462
 463 int tracer_init(struct tracer *t, struct trace_array *tr);
 464 int tracing_is_enabled(void);
 465 void trace_wake_up(void);
 466 void tracing_reset(struct trace_array *tr, int cpu);
 467 void tracing_reset_online_cpus(struct trace_array *tr);
 468 int tracing_open_generic(struct inode *inode, struct file *filp);
 469 struct dentry *tracing_init_dentry(void);
 470 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 471
 472 struct ring_buffer_event;
 473
 474 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
 475                                                     unsigned char type,
 476                                                     unsigned long len,
 477                                                     unsigned long flags,
 478                                                     int pc);
 479 void trace_buffer_unlock_commit(struct trace_array *tr,
 480                                 struct ring_buffer_event *event,
 481                                 unsigned long flags, int pc);
 482
 483 struct ring_buffer_event *
 484 trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
 485                                   unsigned long flags, int pc);
 486 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
 487                                         unsigned long flags, int pc);
 488
 489 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 490                                                 struct trace_array_cpu *data);
 491
 492 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 493                                           int *ent_cpu, u64 *ent_ts);
 494
 495 void tracing_generic_entry_update(struct trace_entry *entry,
 496                                   unsigned long flags,
 497                                   int pc);
 498
 499 void default_wait_pipe(struct trace_iterator *iter);
 500 void poll_wait_pipe(struct trace_iterator *iter);
 501
 502 void ftrace(struct trace_array *tr,
 503                             struct trace_array_cpu *data,
 504                             unsigned long ip,
 505                             unsigned long parent_ip,
 506                             unsigned long flags, int pc);
 507 void tracing_sched_switch_trace(struct trace_array *tr,
 508                                 struct task_struct *prev,
 509                                 struct task_struct *next,
 510                                 unsigned long flags, int pc);
 511 void tracing_record_cmdline(struct task_struct *tsk);
 512
 513 void tracing_sched_wakeup_trace(struct trace_array *tr,
 514                                 struct task_struct *wakee,
 515                                 struct task_struct *cur,
 516                                 unsigned long flags, int pc);
 517 void trace_special(struct trace_array *tr,
 518                    struct trace_array_cpu *data,
 519                    unsigned long arg1,
 520                    unsigned long arg2,
 521                    unsigned long arg3, int pc);
 522 void trace_function(struct trace_array *tr,
 523                     unsigned long ip,
 524                     unsigned long parent_ip,
 525                     unsigned long flags, int pc);
 526
 527 void trace_graph_return(struct ftrace_graph_ret *trace);
 528 int trace_graph_entry(struct ftrace_graph_ent *trace);
 529
 530 void tracing_start_cmdline_record(void);
 531 void tracing_stop_cmdline_record(void);
 532 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 533 void tracing_stop_sched_switch_record(void);
 534 void tracing_start_sched_switch_record(void);
 535 int register_tracer(struct tracer *type);
 536 void unregister_tracer(struct tracer *type);
 537
 538 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 539
 540 extern unsigned long tracing_max_latency;
 541 extern unsigned long tracing_thresh;
 542
 543 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 544 void update_max_tr_single(struct trace_array *tr,
 545                           struct task_struct *tsk, int cpu);
 546
 547 void __trace_stack(struct trace_array *tr,
 548                    unsigned long flags,
 549                    int skip, int pc);
 550
 551 extern cycle_t ftrace_now(int cpu);
 552
 553 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 554 typedef void
 555 (*tracer_switch_func_t)(void *private,
 556                         void *__rq,
 557                         struct task_struct *prev,
 558                         struct task_struct *next);
 559
 560 struct tracer_switch_ops {
 561         tracer_switch_func_t            func;
 562         void                            *private;
 563         struct tracer_switch_ops        *next;
 564 };
 565 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 566
 567 extern void trace_find_cmdline(int pid, char comm[]);
 568
 569 #ifdef CONFIG_DYNAMIC_FTRACE
 570 extern unsigned long ftrace_update_tot_cnt;
 571 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 572 extern int DYN_FTRACE_TEST_NAME(void);
 573 #endif
 574
 575 #ifdef CONFIG_FTRACE_STARTUP_TEST
 576 extern int trace_selftest_startup_function(struct tracer *trace,
 577                                            struct trace_array *tr);
 578 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 579                                                  struct trace_array *tr);
 580 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 581                                           struct trace_array *tr);
 582 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 583                                              struct trace_array *tr);
 584 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 585                                                  struct trace_array *tr);
 586 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 587                                          struct trace_array *tr);
 588 extern int trace_selftest_startup_nop(struct tracer *trace,
 589                                          struct trace_array *tr);
 590 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 591                                                struct trace_array *tr);
 592 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 593                                                struct trace_array *tr);
 594 extern int trace_selftest_startup_branch(struct tracer *trace,
 595                                          struct trace_array *tr);
 596 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 597
 598 extern void *head_page(struct trace_array_cpu *data);
 599 extern long ns2usecs(cycle_t nsec);
 600 extern int
 601 trace_vbprintk(unsigned long ip, int depth, const char *fmt, va_list args);
 602 extern int
 603 trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args);
 604
 605 extern unsigned long trace_flags;
 606
 607 /* Standard output formatting function used for function return traces */
 608 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 609 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 610
 611 #ifdef CONFIG_DYNAMIC_FTRACE
 612 /* TODO: make this variable */
 613 #define FTRACE_GRAPH_MAX_FUNCS          32
 614 extern int ftrace_graph_count;
 615 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 616
 617 static inline int ftrace_graph_addr(unsigned long addr)
 618 {
 619         int i;
 620
 621         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 622                 return 1;
 623
 624         for (i = 0; i < ftrace_graph_count; i++) {
 625                 if (addr == ftrace_graph_funcs[i])
 626                         return 1;
 627         }
 628
 629         return 0;
 630 }
 631 #else
 632 static inline int ftrace_trace_addr(unsigned long addr)
 633 {
 634         return 1;
 635 }
 636 static inline int ftrace_graph_addr(unsigned long addr)
 637 {
 638         return 1;
 639 }
 640 #endif /* CONFIG_DYNAMIC_FTRACE */
 641
 642 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 643 static inline enum print_line_t
 644 print_graph_function(struct trace_iterator *iter)
 645 {
 646         return TRACE_TYPE_UNHANDLED;
 647 }
 648 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 649
 650 extern struct pid *ftrace_pid_trace;
 651
 652 static inline int ftrace_trace_task(struct task_struct *task)
 653 {
 654         if (!ftrace_pid_trace)
 655                 return 1;
 656
 657         return test_tsk_trace_trace(task);
 658 }
 659
 660 /*
 661  * trace_iterator_flags is an enumeration that defines bit
 662  * positions into trace_flags that controls the output.
 663  *
 664  * NOTE: These bits must match the trace_options array in
 665  *       trace.c.
 666  */
 667 enum trace_iterator_flags {
 668         TRACE_ITER_PRINT_PARENT         = 0x01,
 669         TRACE_ITER_SYM_OFFSET           = 0x02,
 670         TRACE_ITER_SYM_ADDR             = 0x04,
 671         TRACE_ITER_VERBOSE              = 0x08,
 672         TRACE_ITER_RAW                  = 0x10,
 673         TRACE_ITER_HEX                  = 0x20,
 674         TRACE_ITER_BIN                  = 0x40,
 675         TRACE_ITER_BLOCK                = 0x80,
 676         TRACE_ITER_STACKTRACE           = 0x100,
 677         TRACE_ITER_SCHED_TREE           = 0x200,
 678         TRACE_ITER_PRINTK               = 0x400,
 679         TRACE_ITER_PREEMPTONLY          = 0x800,
 680         TRACE_ITER_BRANCH               = 0x1000,
 681         TRACE_ITER_ANNOTATE             = 0x2000,
 682         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 683         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 684         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 685         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 686         TRACE_ITER_LATENCY_FMT          = 0x40000,
 687         TRACE_ITER_GLOBAL_CLK           = 0x80000,
 688 };
 689
 690 /*
 691  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 692  * control the output of kernel symbols.
 693  */
 694 #define TRACE_ITER_SYM_MASK \
 695         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 696
 697 extern struct tracer nop_trace;
 698
 699 /**
 700  * ftrace_preempt_disable - disable preemption scheduler safe
 701  *
 702  * When tracing can happen inside the scheduler, there exists
 703  * cases that the tracing might happen before the need_resched
 704  * flag is checked. If this happens and the tracer calls
 705  * preempt_enable (after a disable), a schedule might take place
 706  * causing an infinite recursion.
 707  *
 708  * To prevent this, we read the need_resched flag before
 709  * disabling preemption. When we want to enable preemption we
 710  * check the flag, if it is set, then we call preempt_enable_no_resched.
 711  * Otherwise, we call preempt_enable.
 712  *
 713  * The rational for doing the above is that if need_resched is set
 714  * and we have yet to reschedule, we are either in an atomic location
 715  * (where we do not need to check for scheduling) or we are inside
 716  * the scheduler and do not want to resched.
 717  */
 718 static inline int ftrace_preempt_disable(void)
 719 {
 720         int resched;
 721
 722         resched = need_resched();
 723         preempt_disable_notrace();
 724
 725         return resched;
 726 }
 727
 728 /**
 729  * ftrace_preempt_enable - enable preemption scheduler safe
 730  * @resched: the return value from ftrace_preempt_disable
 731  *
 732  * This is a scheduler safe way to enable preemption and not miss
 733  * any preemption checks. The disabled saved the state of preemption.
 734  * If resched is set, then we are either inside an atomic or
 735  * are inside the scheduler (we would have already scheduled
 736  * otherwise). In this case, we do not want to call normal
 737  * preempt_enable, but preempt_enable_no_resched instead.
 738  */
 739 static inline void ftrace_preempt_enable(int resched)
 740 {
 741         if (resched)
 742                 preempt_enable_no_resched_notrace();
 743         else
 744                 preempt_enable_notrace();
 745 }
 746
 747 #ifdef CONFIG_BRANCH_TRACER
 748 extern int enable_branch_tracing(struct trace_array *tr);
 749 extern void disable_branch_tracing(void);
 750 static inline int trace_branch_enable(struct trace_array *tr)
 751 {
 752         if (trace_flags & TRACE_ITER_BRANCH)
 753                 return enable_branch_tracing(tr);
 754         return 0;
 755 }
 756 static inline void trace_branch_disable(void)
 757 {
 758         /* due to races, always disable */
 759         disable_branch_tracing();
 760 }
 761 #else
 762 static inline int trace_branch_enable(struct trace_array *tr)
 763 {
 764         return 0;
 765 }
 766 static inline void trace_branch_disable(void)
 767 {
 768 }
 769 #endif /* CONFIG_BRANCH_TRACER */
 770
 771 /* set ring buffers to default size if not already done so */
 772 int tracing_update_buffers(void);
 773
 774 /* trace event type bit fields, not numeric */
 775 enum {
 776         TRACE_EVENT_TYPE_PRINTF         = 1,
 777         TRACE_EVENT_TYPE_RAW            = 2,
 778 };
 779
 780 struct ftrace_event_call {
 781         char            *name;
 782         char            *system;
 783         struct dentry   *dir;
 784         int             enabled;
 785         int             (*regfunc)(void);
 786         void            (*unregfunc)(void);
 787         int             id;
 788         int             (*raw_init)(void);
 789         int             (*show_format)(struct trace_seq *s);
 790 };
 791
 792 void event_trace_printk(unsigned long ip, const char *fmt, ...);
 793 extern struct ftrace_event_call __start_ftrace_events[];
 794 extern struct ftrace_event_call __stop_ftrace_events[];
 795
 796 extern const char *__start___trace_bprintk_fmt[];
 797 extern const char *__stop___trace_bprintk_fmt[];
 798
 799 /*
 800  * The double __builtin_constant_p is because gcc will give us an error
 801  * if we try to allocate the static variable to fmt if it is not a
 802  * constant. Even with the outer if statement optimizing out.
 803  */
 804 #define event_trace_printk(ip, fmt, args...)                            \
 805 do {                                                                    \
 806         __trace_printk_check_format(fmt, ##args);                       \
 807         tracing_record_cmdline(current);                                \
 808         if (__builtin_constant_p(fmt)) {                                \
 809                 static const char *trace_printk_fmt                     \
 810                   __attribute__((section("__trace_printk_fmt"))) =      \
 811                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 812                                                                         \
 813                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 814         } else                                                          \
 815                 __trace_printk(ip, fmt, ##args);                        \
 816 } while (0)
 817
 818 #endif /* _LINUX_KERNEL_TRACE_H */