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   1 #ifndef _LINUX_KERNEL_TRACE_H
   2 #define _LINUX_KERNEL_TRACE_H
   3
   4 #include <linux/fs.h>
   5 #include <asm/atomic.h>
   6 #include <linux/sched.h>
   7 #include <linux/clocksource.h>
   8 #include <linux/ring_buffer.h>
   9 #include <linux/mmiotrace.h>
  10 #include <linux/ftrace.h>
  11 #include <trace/boot.h>
  12 #include <linux/kmemtrace.h>
  13 #include <trace/power.h>
  14
  15 #include <linux/trace_seq.h>
  16 #include <linux/ftrace_event.h>
  17
  18 enum trace_type {
  19         __TRACE_FIRST_TYPE = 0,
  20
  21         TRACE_FN,
  22         TRACE_CTX,
  23         TRACE_WAKE,
  24         TRACE_STACK,
  25         TRACE_PRINT,
  26         TRACE_BPRINT,
  27         TRACE_SPECIAL,
  28         TRACE_MMIO_RW,
  29         TRACE_MMIO_MAP,
  30         TRACE_BRANCH,
  31         TRACE_BOOT_CALL,
  32         TRACE_BOOT_RET,
  33         TRACE_GRAPH_RET,
  34         TRACE_GRAPH_ENT,
  35         TRACE_USER_STACK,
  36         TRACE_HW_BRANCHES,
  37         TRACE_KMEM_ALLOC,
  38         TRACE_KMEM_FREE,
  39         TRACE_POWER,
  40         TRACE_BLK,
  41
  42         __TRACE_LAST_TYPE,
  43 };
  44
  45 enum kmemtrace_type_id {
  46         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
  47         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
  48         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
  49 };
  50
  51 extern struct tracer boot_tracer;
  52
  53 #undef __field
  54 #define __field(type, item)             type    item;
  55
  56 #undef __array
  57 #define __array(type, item, size)       type    item[size];
  58
  59 #undef __dynamic_array
  60 #define __dynamic_array(type, item)     type    item[];
  61
  62 #undef F_STRUCT
  63 #define F_STRUCT(args...)               args
  64
  65 #undef FTRACE_ENTRY
  66 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)     \
  67         struct struct_name {                                    \
  68                 struct trace_entry      ent;                    \
  69                 tstruct                                         \
  70         }
  71
  72 #undef TP_ARGS
  73 #define TP_ARGS(args...)        args
  74
  75 #undef FTRACE_ENTRY_DUP
  76 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
  77
  78 #include "trace_entries.h"
  79
  80 /*
  81  * syscalls are special, and need special handling, this is why
  82  * they are not included in trace_entries.h
  83  */
  84 struct syscall_trace_enter {
  85         struct trace_entry      ent;
  86         int                     nr;
  87         unsigned long           args[];
  88 };
  89
  90 struct syscall_trace_exit {
  91         struct trace_entry      ent;
  92         int                     nr;
  93         unsigned long           ret;
  94 };
  95
  96 /*
  97  * trace_flag_type is an enumeration that holds different
  98  * states when a trace occurs. These are:
  99  *  IRQS_OFF            - interrupts were disabled
 100  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 101  *  NEED_RESCHED        - reschedule is requested
 102  *  HARDIRQ             - inside an interrupt handler
 103  *  SOFTIRQ             - inside a softirq handler
 104  */
 105 enum trace_flag_type {
 106         TRACE_FLAG_IRQS_OFF             = 0x01,
 107         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 108         TRACE_FLAG_NEED_RESCHED         = 0x04,
 109         TRACE_FLAG_HARDIRQ              = 0x08,
 110         TRACE_FLAG_SOFTIRQ              = 0x10,
 111 };
 112
 113 #define TRACE_BUF_SIZE          1024
 114
 115 /*
 116  * The CPU trace array - it consists of thousands of trace entries
 117  * plus some other descriptor data: (for example which task started
 118  * the trace, etc.)
 119  */
 120 struct trace_array_cpu {
 121         atomic_t                disabled;
 122         void                    *buffer_page;   /* ring buffer spare */
 123
 124         unsigned long           saved_latency;
 125         unsigned long           critical_start;
 126         unsigned long           critical_end;
 127         unsigned long           critical_sequence;
 128         unsigned long           nice;
 129         unsigned long           policy;
 130         unsigned long           rt_priority;
 131         unsigned long           skipped_entries;
 132         cycle_t                 preempt_timestamp;
 133         pid_t                   pid;
 134         uid_t                   uid;
 135         char                    comm[TASK_COMM_LEN];
 136 };
 137
 138 /*
 139  * The trace array - an array of per-CPU trace arrays. This is the
 140  * highest level data structure that individual tracers deal with.
 141  * They have on/off state as well:
 142  */
 143 struct trace_array {
 144         struct ring_buffer      *buffer;
 145         unsigned long           entries;
 146         int                     cpu;
 147         cycle_t                 time_start;
 148         struct task_struct      *waiter;
 149         struct trace_array_cpu  *data[NR_CPUS];
 150 };
 151
 152 #define FTRACE_CMP_TYPE(var, type) \
 153         __builtin_types_compatible_p(typeof(var), type *)
 154
 155 #undef IF_ASSIGN
 156 #define IF_ASSIGN(var, entry, etype, id)                \
 157         if (FTRACE_CMP_TYPE(var, etype)) {              \
 158                 var = (typeof(var))(entry);             \
 159                 WARN_ON(id && (entry)->type != id);     \
 160                 break;                                  \
 161         }
 162
 163 /* Will cause compile errors if type is not found. */
 164 extern void __ftrace_bad_type(void);
 165
 166 /*
 167  * The trace_assign_type is a verifier that the entry type is
 168  * the same as the type being assigned. To add new types simply
 169  * add a line with the following format:
 170  *
 171  * IF_ASSIGN(var, ent, type, id);
 172  *
 173  *  Where "type" is the trace type that includes the trace_entry
 174  *  as the "ent" item. And "id" is the trace identifier that is
 175  *  used in the trace_type enum.
 176  *
 177  *  If the type can have more than one id, then use zero.
 178  */
 179 #define trace_assign_type(var, ent)                                     \
 180         do {                                                            \
 181                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 182                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 183                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 184                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 185                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 186                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 187                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 188                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 189                           TRACE_MMIO_RW);                               \
 190                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 191                           TRACE_MMIO_MAP);                              \
 192                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 193                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 194                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 195                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 196                           TRACE_GRAPH_ENT);             \
 197                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 198                           TRACE_GRAPH_RET);             \
 199                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 200                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 201                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 202                           TRACE_KMEM_ALLOC);    \
 203                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 204                           TRACE_KMEM_FREE);     \
 205                 __ftrace_bad_type();                                    \
 206         } while (0)
 207
 208 /*
 209  * An option specific to a tracer. This is a boolean value.
 210  * The bit is the bit index that sets its value on the
 211  * flags value in struct tracer_flags.
 212  */
 213 struct tracer_opt {
 214         const char      *name; /* Will appear on the trace_options file */
 215         u32             bit; /* Mask assigned in val field in tracer_flags */
 216 };
 217
 218 /*
 219  * The set of specific options for a tracer. Your tracer
 220  * have to set the initial value of the flags val.
 221  */
 222 struct tracer_flags {
 223         u32                     val;
 224         struct tracer_opt       *opts;
 225 };
 226
 227 /* Makes more easy to define a tracer opt */
 228 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 229
 230
 231 /**
 232  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 233  * @name: the name chosen to select it on the available_tracers file
 234  * @init: called when one switches to this tracer (echo name > current_tracer)
 235  * @reset: called when one switches to another tracer
 236  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 237  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 238  * @open: called when the trace file is opened
 239  * @pipe_open: called when the trace_pipe file is opened
 240  * @wait_pipe: override how the user waits for traces on trace_pipe
 241  * @close: called when the trace file is released
 242  * @read: override the default read callback on trace_pipe
 243  * @splice_read: override the default splice_read callback on trace_pipe
 244  * @selftest: selftest to run on boot (see trace_selftest.c)
 245  * @print_headers: override the first lines that describe your columns
 246  * @print_line: callback that prints a trace
 247  * @set_flag: signals one of your private flags changed (trace_options file)
 248  * @flags: your private flags
 249  */
 250 struct tracer {
 251         const char              *name;
 252         int                     (*init)(struct trace_array *tr);
 253         void                    (*reset)(struct trace_array *tr);
 254         void                    (*start)(struct trace_array *tr);
 255         void                    (*stop)(struct trace_array *tr);
 256         void                    (*open)(struct trace_iterator *iter);
 257         void                    (*pipe_open)(struct trace_iterator *iter);
 258         void                    (*wait_pipe)(struct trace_iterator *iter);
 259         void                    (*close)(struct trace_iterator *iter);
 260         ssize_t                 (*read)(struct trace_iterator *iter,
 261                                         struct file *filp, char __user *ubuf,
 262                                         size_t cnt, loff_t *ppos);
 263         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 264                                                struct file *filp,
 265                                                loff_t *ppos,
 266                                                struct pipe_inode_info *pipe,
 267                                                size_t len,
 268                                                unsigned int flags);
 269 #ifdef CONFIG_FTRACE_STARTUP_TEST
 270         int                     (*selftest)(struct tracer *trace,
 271                                             struct trace_array *tr);
 272 #endif
 273         void                    (*print_header)(struct seq_file *m);
 274         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 275         /* If you handled the flag setting, return 0 */
 276         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 277         struct tracer           *next;
 278         int                     print_max;
 279         struct tracer_flags     *flags;
 280 };
 281
 282
 283 #define TRACE_PIPE_ALL_CPU      -1
 284
 285 int tracer_init(struct tracer *t, struct trace_array *tr);
 286 int tracing_is_enabled(void);
 287 void trace_wake_up(void);
 288 void tracing_reset(struct trace_array *tr, int cpu);
 289 void tracing_reset_online_cpus(struct trace_array *tr);
 290 void tracing_reset_current(int cpu);
 291 void tracing_reset_current_online_cpus(void);
 292 int tracing_open_generic(struct inode *inode, struct file *filp);
 293 struct dentry *trace_create_file(const char *name,
 294                                  mode_t mode,
 295                                  struct dentry *parent,
 296                                  void *data,
 297                                  const struct file_operations *fops);
 298
 299 struct dentry *tracing_init_dentry(void);
 300 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 301
 302 struct ring_buffer_event;
 303
 304 struct ring_buffer_event *
 305 trace_buffer_lock_reserve(struct ring_buffer *buffer,
 306                           int type,
 307                           unsigned long len,
 308                           unsigned long flags,
 309                           int pc);
 310 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
 311                                 struct ring_buffer_event *event,
 312                                 unsigned long flags, int pc);
 313
 314 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 315                                                 struct trace_array_cpu *data);
 316
 317 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 318                                           int *ent_cpu, u64 *ent_ts);
 319
 320 void default_wait_pipe(struct trace_iterator *iter);
 321 void poll_wait_pipe(struct trace_iterator *iter);
 322
 323 void ftrace(struct trace_array *tr,
 324                             struct trace_array_cpu *data,
 325                             unsigned long ip,
 326                             unsigned long parent_ip,
 327                             unsigned long flags, int pc);
 328 void tracing_sched_switch_trace(struct trace_array *tr,
 329                                 struct task_struct *prev,
 330                                 struct task_struct *next,
 331                                 unsigned long flags, int pc);
 332
 333 void tracing_sched_wakeup_trace(struct trace_array *tr,
 334                                 struct task_struct *wakee,
 335                                 struct task_struct *cur,
 336                                 unsigned long flags, int pc);
 337 void trace_special(struct trace_array *tr,
 338                    struct trace_array_cpu *data,
 339                    unsigned long arg1,
 340                    unsigned long arg2,
 341                    unsigned long arg3, int pc);
 342 void trace_function(struct trace_array *tr,
 343                     unsigned long ip,
 344                     unsigned long parent_ip,
 345                     unsigned long flags, int pc);
 346
 347 void trace_graph_return(struct ftrace_graph_ret *trace);
 348 int trace_graph_entry(struct ftrace_graph_ent *trace);
 349 void set_graph_array(struct trace_array *tr);
 350
 351 void tracing_start_cmdline_record(void);
 352 void tracing_stop_cmdline_record(void);
 353 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 354 void tracing_stop_sched_switch_record(void);
 355 void tracing_start_sched_switch_record(void);
 356 int register_tracer(struct tracer *type);
 357 void unregister_tracer(struct tracer *type);
 358 int is_tracing_stopped(void);
 359
 360 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 361
 362 #ifdef CONFIG_TRACER_MAX_TRACE
 363 extern unsigned long tracing_max_latency;
 364 extern unsigned long tracing_thresh;
 365
 366 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 367 void update_max_tr_single(struct trace_array *tr,
 368                           struct task_struct *tsk, int cpu);
 369 #endif /* CONFIG_TRACER_MAX_TRACE */
 370
 371 #ifdef CONFIG_STACKTRACE
 372 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 373                         int skip, int pc);
 374
 375 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 376                             int pc);
 377
 378 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 379                    int pc);
 380 #else
 381 static inline void ftrace_trace_stack(struct trace_array *tr,
 382                                       unsigned long flags, int skip, int pc)
 383 {
 384 }
 385
 386 static inline void ftrace_trace_userstack(struct trace_array *tr,
 387                                           unsigned long flags, int pc)
 388 {
 389 }
 390
 391 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 392                                  int skip, int pc)
 393 {
 394 }
 395 #endif /* CONFIG_STACKTRACE */
 396
 397 extern cycle_t ftrace_now(int cpu);
 398
 399 extern void trace_find_cmdline(int pid, char comm[]);
 400
 401 #ifdef CONFIG_DYNAMIC_FTRACE
 402 extern unsigned long ftrace_update_tot_cnt;
 403 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 404 extern int DYN_FTRACE_TEST_NAME(void);
 405 #endif
 406
 407 extern int ring_buffer_expanded;
 408 extern bool tracing_selftest_disabled;
 409 DECLARE_PER_CPU(local_t, ftrace_cpu_disabled);
 410
 411 #ifdef CONFIG_FTRACE_STARTUP_TEST
 412 extern int trace_selftest_startup_function(struct tracer *trace,
 413                                            struct trace_array *tr);
 414 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 415                                                  struct trace_array *tr);
 416 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 417                                           struct trace_array *tr);
 418 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 419                                              struct trace_array *tr);
 420 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 421                                                  struct trace_array *tr);
 422 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 423                                          struct trace_array *tr);
 424 extern int trace_selftest_startup_nop(struct tracer *trace,
 425                                          struct trace_array *tr);
 426 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 427                                                struct trace_array *tr);
 428 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 429                                                struct trace_array *tr);
 430 extern int trace_selftest_startup_branch(struct tracer *trace,
 431                                          struct trace_array *tr);
 432 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
 433                                               struct trace_array *tr);
 434 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 435
 436 extern void *head_page(struct trace_array_cpu *data);
 437 extern unsigned long long ns2usecs(cycle_t nsec);
 438 extern int
 439 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 440 extern int
 441 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 442 extern int
 443 trace_array_vprintk(struct trace_array *tr,
 444                     unsigned long ip, const char *fmt, va_list args);
 445 int trace_array_printk(struct trace_array *tr,
 446                        unsigned long ip, const char *fmt, ...);
 447
 448 extern unsigned long trace_flags;
 449
 450 extern int trace_clock_id;
 451
 452 /* Standard output formatting function used for function return traces */
 453 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 454 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 455 extern enum print_line_t
 456 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 457
 458 #ifdef CONFIG_DYNAMIC_FTRACE
 459 /* TODO: make this variable */
 460 #define FTRACE_GRAPH_MAX_FUNCS          32
 461 extern int ftrace_graph_count;
 462 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 463
 464 static inline int ftrace_graph_addr(unsigned long addr)
 465 {
 466         int i;
 467
 468         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 469                 return 1;
 470
 471         for (i = 0; i < ftrace_graph_count; i++) {
 472                 if (addr == ftrace_graph_funcs[i])
 473                         return 1;
 474         }
 475
 476         return 0;
 477 }
 478 #else
 479 static inline int ftrace_trace_addr(unsigned long addr)
 480 {
 481         return 1;
 482 }
 483 static inline int ftrace_graph_addr(unsigned long addr)
 484 {
 485         return 1;
 486 }
 487 #endif /* CONFIG_DYNAMIC_FTRACE */
 488 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 489 static inline enum print_line_t
 490 print_graph_function(struct trace_iterator *iter)
 491 {
 492         return TRACE_TYPE_UNHANDLED;
 493 }
 494 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 495
 496 extern struct pid *ftrace_pid_trace;
 497
 498 #ifdef CONFIG_FUNCTION_TRACER
 499 static inline int ftrace_trace_task(struct task_struct *task)
 500 {
 501         if (!ftrace_pid_trace)
 502                 return 1;
 503
 504         return test_tsk_trace_trace(task);
 505 }
 506 #else
 507 static inline int ftrace_trace_task(struct task_struct *task)
 508 {
 509         return 1;
 510 }
 511 #endif
 512
 513 /*
 514  * struct trace_parser - servers for reading the user input separated by spaces
 515  * @cont: set if the input is not complete - no final space char was found
 516  * @buffer: holds the parsed user input
 517  * @idx: user input lenght
 518  * @size: buffer size
 519  */
 520 struct trace_parser {
 521         bool            cont;
 522         char            *buffer;
 523         unsigned        idx;
 524         unsigned        size;
 525 };
 526
 527 static inline bool trace_parser_loaded(struct trace_parser *parser)
 528 {
 529         return (parser->idx != 0);
 530 }
 531
 532 static inline bool trace_parser_cont(struct trace_parser *parser)
 533 {
 534         return parser->cont;
 535 }
 536
 537 static inline void trace_parser_clear(struct trace_parser *parser)
 538 {
 539         parser->cont = false;
 540         parser->idx = 0;
 541 }
 542
 543 extern int trace_parser_get_init(struct trace_parser *parser, int size);
 544 extern void trace_parser_put(struct trace_parser *parser);
 545 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 546         size_t cnt, loff_t *ppos);
 547
 548 /*
 549  * trace_iterator_flags is an enumeration that defines bit
 550  * positions into trace_flags that controls the output.
 551  *
 552  * NOTE: These bits must match the trace_options array in
 553  *       trace.c.
 554  */
 555 enum trace_iterator_flags {
 556         TRACE_ITER_PRINT_PARENT         = 0x01,
 557         TRACE_ITER_SYM_OFFSET           = 0x02,
 558         TRACE_ITER_SYM_ADDR             = 0x04,
 559         TRACE_ITER_VERBOSE              = 0x08,
 560         TRACE_ITER_RAW                  = 0x10,
 561         TRACE_ITER_HEX                  = 0x20,
 562         TRACE_ITER_BIN                  = 0x40,
 563         TRACE_ITER_BLOCK                = 0x80,
 564         TRACE_ITER_STACKTRACE           = 0x100,
 565         TRACE_ITER_SCHED_TREE           = 0x200,
 566         TRACE_ITER_PRINTK               = 0x400,
 567         TRACE_ITER_PREEMPTONLY          = 0x800,
 568         TRACE_ITER_BRANCH               = 0x1000,
 569         TRACE_ITER_ANNOTATE             = 0x2000,
 570         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 571         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 572         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 573         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 574         TRACE_ITER_LATENCY_FMT          = 0x40000,
 575         TRACE_ITER_SLEEP_TIME           = 0x80000,
 576         TRACE_ITER_GRAPH_TIME           = 0x100000,
 577 };
 578
 579 /*
 580  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 581  * control the output of kernel symbols.
 582  */
 583 #define TRACE_ITER_SYM_MASK \
 584         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 585
 586 extern struct tracer nop_trace;
 587
 588 /**
 589  * ftrace_preempt_disable - disable preemption scheduler safe
 590  *
 591  * When tracing can happen inside the scheduler, there exists
 592  * cases that the tracing might happen before the need_resched
 593  * flag is checked. If this happens and the tracer calls
 594  * preempt_enable (after a disable), a schedule might take place
 595  * causing an infinite recursion.
 596  *
 597  * To prevent this, we read the need_resched flag before
 598  * disabling preemption. When we want to enable preemption we
 599  * check the flag, if it is set, then we call preempt_enable_no_resched.
 600  * Otherwise, we call preempt_enable.
 601  *
 602  * The rational for doing the above is that if need_resched is set
 603  * and we have yet to reschedule, we are either in an atomic location
 604  * (where we do not need to check for scheduling) or we are inside
 605  * the scheduler and do not want to resched.
 606  */
 607 static inline int ftrace_preempt_disable(void)
 608 {
 609         int resched;
 610
 611         resched = need_resched();
 612         preempt_disable_notrace();
 613
 614         return resched;
 615 }
 616
 617 /**
 618  * ftrace_preempt_enable - enable preemption scheduler safe
 619  * @resched: the return value from ftrace_preempt_disable
 620  *
 621  * This is a scheduler safe way to enable preemption and not miss
 622  * any preemption checks. The disabled saved the state of preemption.
 623  * If resched is set, then we are either inside an atomic or
 624  * are inside the scheduler (we would have already scheduled
 625  * otherwise). In this case, we do not want to call normal
 626  * preempt_enable, but preempt_enable_no_resched instead.
 627  */
 628 static inline void ftrace_preempt_enable(int resched)
 629 {
 630         if (resched)
 631                 preempt_enable_no_resched_notrace();
 632         else
 633                 preempt_enable_notrace();
 634 }
 635
 636 #ifdef CONFIG_BRANCH_TRACER
 637 extern int enable_branch_tracing(struct trace_array *tr);
 638 extern void disable_branch_tracing(void);
 639 static inline int trace_branch_enable(struct trace_array *tr)
 640 {
 641         if (trace_flags & TRACE_ITER_BRANCH)
 642                 return enable_branch_tracing(tr);
 643         return 0;
 644 }
 645 static inline void trace_branch_disable(void)
 646 {
 647         /* due to races, always disable */
 648         disable_branch_tracing();
 649 }
 650 #else
 651 static inline int trace_branch_enable(struct trace_array *tr)
 652 {
 653         return 0;
 654 }
 655 static inline void trace_branch_disable(void)
 656 {
 657 }
 658 #endif /* CONFIG_BRANCH_TRACER */
 659
 660 /* set ring buffers to default size if not already done so */
 661 int tracing_update_buffers(void);
 662
 663 /* trace event type bit fields, not numeric */
 664 enum {
 665         TRACE_EVENT_TYPE_PRINTF         = 1,
 666         TRACE_EVENT_TYPE_RAW            = 2,
 667 };
 668
 669 struct ftrace_event_field {
 670         struct list_head        link;
 671         char                    *name;
 672         char                    *type;
 673         int                     filter_type;
 674         int                     offset;
 675         int                     size;
 676         int                     is_signed;
 677 };
 678
 679 struct event_filter {
 680         int                     n_preds;
 681         struct filter_pred      **preds;
 682         char                    *filter_string;
 683         bool                    no_reset;
 684 };
 685
 686 struct event_subsystem {
 687         struct list_head        list;
 688         const char              *name;
 689         struct dentry           *entry;
 690         struct event_filter     *filter;
 691         int                     nr_events;
 692 };
 693
 694 struct filter_pred;
 695
 696 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 697                                  int val1, int val2);
 698
 699 struct filter_pred {
 700         filter_pred_fn_t fn;
 701         u64 val;
 702         char str_val[MAX_FILTER_STR_VAL];
 703         int str_len;
 704         char *field_name;
 705         int offset;
 706         int not;
 707         int op;
 708         int pop_n;
 709 };
 710
 711 extern void print_event_filter(struct ftrace_event_call *call,
 712                                struct trace_seq *s);
 713 extern int apply_event_filter(struct ftrace_event_call *call,
 714                               char *filter_string);
 715 extern int apply_subsystem_event_filter(struct event_subsystem *system,
 716                                         char *filter_string);
 717 extern void print_subsystem_event_filter(struct event_subsystem *system,
 718                                          struct trace_seq *s);
 719 extern int filter_assign_type(const char *type);
 720
 721 static inline int
 722 filter_check_discard(struct ftrace_event_call *call, void *rec,
 723                      struct ring_buffer *buffer,
 724                      struct ring_buffer_event *event)
 725 {
 726         if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) {
 727                 ring_buffer_discard_commit(buffer, event);
 728                 return 1;
 729         }
 730
 731         return 0;
 732 }
 733
 734 extern struct mutex event_mutex;
 735 extern struct list_head ftrace_events;
 736
 737 extern const char *__start___trace_bprintk_fmt[];
 738 extern const char *__stop___trace_bprintk_fmt[];
 739
 740 #undef TRACE_EVENT_FORMAT
 741 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
 742         extern struct ftrace_event_call event_##call;
 743 #undef TRACE_EVENT_FORMAT_NOFILTER
 744 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt)
 745 #include "trace_event_types.h"
 746
 747 #endif /* _LINUX_KERNEL_TRACE_H */