LXR linux/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/tracepoint.h>
  11#include <linux/ftrace.h>
  12#include <trace/boot.h>
  13#include <linux/kmemtrace.h>
  14#include <linux/hw_breakpoint.h>
  15
  16#include <linux/trace_seq.h>
  17#include <linux/ftrace_event.h>
  18
  19enum trace_type {
  20        __TRACE_FIRST_TYPE = 0,
  21
  22        TRACE_FN,
  23        TRACE_CTX,
  24        TRACE_WAKE,
  25        TRACE_STACK,
  26        TRACE_PRINT,
  27        TRACE_BPRINT,
  28        TRACE_SPECIAL,
  29        TRACE_MMIO_RW,
  30        TRACE_MMIO_MAP,
  31        TRACE_BRANCH,
  32        TRACE_BOOT_CALL,
  33        TRACE_BOOT_RET,
  34        TRACE_GRAPH_RET,
  35        TRACE_GRAPH_ENT,
  36        TRACE_USER_STACK,
  37        TRACE_KMEM_ALLOC,
  38        TRACE_KMEM_FREE,
  39        TRACE_BLK,
  40        TRACE_KSYM,
  41
  42        __TRACE_LAST_TYPE,
  43};
  44
  45enum 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
  51extern struct tracer boot_tracer;
  52
  53#undef __field
  54#define __field(type, item)             type    item;
  55
  56#undef __field_struct
  57#define __field_struct(type, item)      __field(type, item)
  58
  59#undef __field_desc
  60#define __field_desc(type, container, item)
  61
  62#undef __array
  63#define __array(type, item, size)       type    item[size];
  64
  65#undef __array_desc
  66#define __array_desc(type, container, item, size)
  67
  68#undef __dynamic_array
  69#define __dynamic_array(type, item)     type    item[];
  70
  71#undef F_STRUCT
  72#define F_STRUCT(args...)               args
  73
  74#undef FTRACE_ENTRY
  75#define FTRACE_ENTRY(name, struct_name, id, tstruct, print)     \
  76        struct struct_name {                                    \
  77                struct trace_entry      ent;                    \
  78                tstruct                                         \
  79        }
  80
  81#undef TP_ARGS
  82#define TP_ARGS(args...)        args
  83
  84#undef FTRACE_ENTRY_DUP
  85#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
  86
  87#include "trace_entries.h"
  88
  89/*
  90 * syscalls are special, and need special handling, this is why
  91 * they are not included in trace_entries.h
  92 */
  93struct syscall_trace_enter {
  94        struct trace_entry      ent;
  95        int                     nr;
  96        unsigned long           args[];
  97};
  98
  99struct syscall_trace_exit {
 100        struct trace_entry      ent;
 101        int                     nr;
 102        long                    ret;
 103};
 104
 105struct kprobe_trace_entry_head {
 106        struct trace_entry      ent;
 107        unsigned long           ip;
 108};
 109
 110struct kretprobe_trace_entry_head {
 111        struct trace_entry      ent;
 112        unsigned long           func;
 113        unsigned long           ret_ip;
 114};
 115
 116/*
 117 * trace_flag_type is an enumeration that holds different
 118 * states when a trace occurs. These are:
 119 *  IRQS_OFF            - interrupts were disabled
 120 *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 121 *  NEED_RESCHED        - reschedule is requested
 122 *  HARDIRQ             - inside an interrupt handler
 123 *  SOFTIRQ             - inside a softirq handler
 124 */
 125enum trace_flag_type {
 126        TRACE_FLAG_IRQS_OFF             = 0x01,
 127        TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 128        TRACE_FLAG_NEED_RESCHED         = 0x04,
 129        TRACE_FLAG_HARDIRQ              = 0x08,
 130        TRACE_FLAG_SOFTIRQ              = 0x10,
 131};
 132
 133#define TRACE_BUF_SIZE          1024
 134
 135/*
 136 * The CPU trace array - it consists of thousands of trace entries
 137 * plus some other descriptor data: (for example which task started
 138 * the trace, etc.)
 139 */
 140struct trace_array_cpu {
 141        atomic_t                disabled;
 142        void                    *buffer_page;   /* ring buffer spare */
 143
 144        unsigned long           saved_latency;
 145        unsigned long           critical_start;
 146        unsigned long           critical_end;
 147        unsigned long           critical_sequence;
 148        unsigned long           nice;
 149        unsigned long           policy;
 150        unsigned long           rt_priority;
 151        unsigned long           skipped_entries;
 152        cycle_t                 preempt_timestamp;
 153        pid_t                   pid;
 154        uid_t                   uid;
 155        char                    comm[TASK_COMM_LEN];
 156};
 157
 158/*
 159 * The trace array - an array of per-CPU trace arrays. This is the
 160 * highest level data structure that individual tracers deal with.
 161 * They have on/off state as well:
 162 */
 163struct trace_array {
 164        struct ring_buffer      *buffer;
 165        unsigned long           entries;
 166        int                     cpu;
 167        cycle_t                 time_start;
 168        struct task_struct      *waiter;
 169        struct trace_array_cpu  *data[NR_CPUS];
 170};
 171
 172#define FTRACE_CMP_TYPE(var, type) \
 173        __builtin_types_compatible_p(typeof(var), type *)
 174
 175#undef IF_ASSIGN
 176#define IF_ASSIGN(var, entry, etype, id)                \
 177        if (FTRACE_CMP_TYPE(var, etype)) {              \
 178                var = (typeof(var))(entry);             \
 179                WARN_ON(id && (entry)->type != id);     \
 180                break;                                  \
 181        }
 182
 183/* Will cause compile errors if type is not found. */
 184extern void __ftrace_bad_type(void);
 185
 186/*
 187 * The trace_assign_type is a verifier that the entry type is
 188 * the same as the type being assigned. To add new types simply
 189 * add a line with the following format:
 190 *
 191 * IF_ASSIGN(var, ent, type, id);
 192 *
 193 *  Where "type" is the trace type that includes the trace_entry
 194 *  as the "ent" item. And "id" is the trace identifier that is
 195 *  used in the trace_type enum.
 196 *
 197 *  If the type can have more than one id, then use zero.
 198 */
 199#define trace_assign_type(var, ent)                                     \
 200        do {                                                            \
 201                IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 202                IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 203                IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 204                IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 205                IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 206                IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 207                IF_ASSIGN(var, ent, struct special_entry, 0);           \
 208                IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 209                          TRACE_MMIO_RW);                               \
 210                IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 211                          TRACE_MMIO_MAP);                              \
 212                IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 213                IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 214                IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 215                IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 216                          TRACE_GRAPH_ENT);             \
 217                IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 218                          TRACE_GRAPH_RET);             \
 219                IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 220                          TRACE_KMEM_ALLOC);    \
 221                IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 222                          TRACE_KMEM_FREE);     \
 223                IF_ASSIGN(var, ent, struct ksym_trace_entry, TRACE_KSYM);\
 224                __ftrace_bad_type();                                    \
 225        } while (0)
 226
 227/*
 228 * An option specific to a tracer. This is a boolean value.
 229 * The bit is the bit index that sets its value on the
 230 * flags value in struct tracer_flags.
 231 */
 232struct tracer_opt {
 233        const char      *name; /* Will appear on the trace_options file */
 234        u32             bit; /* Mask assigned in val field in tracer_flags */
 235};
 236
 237/*
 238 * The set of specific options for a tracer. Your tracer
 239 * have to set the initial value of the flags val.
 240 */
 241struct tracer_flags {
 242        u32                     val;
 243        struct tracer_opt       *opts;
 244};
 245
 246/* Makes more easy to define a tracer opt */
 247#define TRACER_OPT(s, b)        .name = #s, .bit = b
 248
 249
 250/**
 251 * struct tracer - a specific tracer and its callbacks to interact with debugfs
 252 * @name: the name chosen to select it on the available_tracers file
 253 * @init: called when one switches to this tracer (echo name > current_tracer)
 254 * @reset: called when one switches to another tracer
 255 * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 256 * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 257 * @open: called when the trace file is opened
 258 * @pipe_open: called when the trace_pipe file is opened
 259 * @wait_pipe: override how the user waits for traces on trace_pipe
 260 * @close: called when the trace file is released
 261 * @pipe_close: called when the trace_pipe file is released
 262 * @read: override the default read callback on trace_pipe
 263 * @splice_read: override the default splice_read callback on trace_pipe
 264 * @selftest: selftest to run on boot (see trace_selftest.c)
 265 * @print_headers: override the first lines that describe your columns
 266 * @print_line: callback that prints a trace
 267 * @set_flag: signals one of your private flags changed (trace_options file)
 268 * @flags: your private flags
 269 */
 270struct tracer {
 271        const char              *name;
 272        int                     (*init)(struct trace_array *tr);
 273        void                    (*reset)(struct trace_array *tr);
 274        void                    (*start)(struct trace_array *tr);
 275        void                    (*stop)(struct trace_array *tr);
 276        void                    (*open)(struct trace_iterator *iter);
 277        void                    (*pipe_open)(struct trace_iterator *iter);
 278        void                    (*wait_pipe)(struct trace_iterator *iter);
 279        void                    (*close)(struct trace_iterator *iter);
 280        void                    (*pipe_close)(struct trace_iterator *iter);
 281        ssize_t                 (*read)(struct trace_iterator *iter,
 282                                        struct file *filp, char __user *ubuf,
 283                                        size_t cnt, loff_t *ppos);
 284        ssize_t                 (*splice_read)(struct trace_iterator *iter,
 285                                               struct file *filp,
 286                                               loff_t *ppos,
 287                                               struct pipe_inode_info *pipe,
 288                                               size_t len,
 289                                               unsigned int flags);
 290#ifdef CONFIG_FTRACE_STARTUP_TEST
 291        int                     (*selftest)(struct tracer *trace,
 292                                            struct trace_array *tr);
 293#endif
 294        void                    (*print_header)(struct seq_file *m);
 295        enum print_line_t       (*print_line)(struct trace_iterator *iter);
 296        /* If you handled the flag setting, return 0 */
 297        int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 298        struct tracer           *next;
 299        int                     print_max;
 300        struct tracer_flags     *flags;
 301};
 302
 303
 304#define TRACE_PIPE_ALL_CPU      -1
 305
 306int tracer_init(struct tracer *t, struct trace_array *tr);
 307int tracing_is_enabled(void);
 308void trace_wake_up(void);
 309void tracing_reset(struct trace_array *tr, int cpu);
 310void tracing_reset_online_cpus(struct trace_array *tr);
 311void tracing_reset_current(int cpu);
 312void tracing_reset_current_online_cpus(void);
 313int tracing_open_generic(struct inode *inode, struct file *filp);
 314struct dentry *trace_create_file(const char *name,
 315                                 mode_t mode,
 316                                 struct dentry *parent,
 317                                 void *data,
 318                                 const struct file_operations *fops);
 319
 320struct dentry *tracing_init_dentry(void);
 321void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 322
 323struct ring_buffer_event;
 324
 325struct ring_buffer_event *
 326trace_buffer_lock_reserve(struct ring_buffer *buffer,
 327                          int type,
 328                          unsigned long len,
 329                          unsigned long flags,
 330                          int pc);
 331void trace_buffer_unlock_commit(struct ring_buffer *buffer,
 332                                struct ring_buffer_event *event,
 333                                unsigned long flags, int pc);
 334
 335struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 336                                                struct trace_array_cpu *data);
 337
 338struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 339                                          int *ent_cpu, u64 *ent_ts);
 340
 341void default_wait_pipe(struct trace_iterator *iter);
 342void poll_wait_pipe(struct trace_iterator *iter);
 343
 344void ftrace(struct trace_array *tr,
 345                            struct trace_array_cpu *data,
 346                            unsigned long ip,
 347                            unsigned long parent_ip,
 348                            unsigned long flags, int pc);
 349void tracing_sched_switch_trace(struct trace_array *tr,
 350                                struct task_struct *prev,
 351                                struct task_struct *next,
 352                                unsigned long flags, int pc);
 353
 354void tracing_sched_wakeup_trace(struct trace_array *tr,
 355                                struct task_struct *wakee,
 356                                struct task_struct *cur,
 357                                unsigned long flags, int pc);
 358void trace_special(struct trace_array *tr,
 359                   struct trace_array_cpu *data,
 360                   unsigned long arg1,
 361                   unsigned long arg2,
 362                   unsigned long arg3, int pc);
 363void trace_function(struct trace_array *tr,
 364                    unsigned long ip,
 365                    unsigned long parent_ip,
 366                    unsigned long flags, int pc);
 367void trace_default_header(struct seq_file *m);
 368void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
 369int trace_empty(struct trace_iterator *iter);
 370
 371void trace_graph_return(struct ftrace_graph_ret *trace);
 372int trace_graph_entry(struct ftrace_graph_ent *trace);
 373void set_graph_array(struct trace_array *tr);
 374
 375void tracing_start_cmdline_record(void);
 376void tracing_stop_cmdline_record(void);
 377void tracing_sched_switch_assign_trace(struct trace_array *tr);
 378void tracing_stop_sched_switch_record(void);
 379void tracing_start_sched_switch_record(void);
 380int register_tracer(struct tracer *type);
 381void unregister_tracer(struct tracer *type);
 382int is_tracing_stopped(void);
 383
 384extern int process_new_ksym_entry(char *ksymname, int op, unsigned long addr);
 385
 386extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 387
 388extern unsigned long tracing_thresh;
 389
 390#ifdef CONFIG_TRACER_MAX_TRACE
 391extern unsigned long tracing_max_latency;
 392
 393void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 394void update_max_tr_single(struct trace_array *tr,
 395                          struct task_struct *tsk, int cpu);
 396#endif /* CONFIG_TRACER_MAX_TRACE */
 397
 398#ifdef CONFIG_STACKTRACE
 399void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 400                        int skip, int pc);
 401
 402void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 403                            int pc);
 404
 405void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 406                   int pc);
 407#else
 408static inline void ftrace_trace_stack(struct ring_buffer *buffer,
 409                                      unsigned long flags, int skip, int pc)
 410{
 411}
 412
 413static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
 414                                          unsigned long flags, int pc)
 415{
 416}
 417
 418static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 419                                 int skip, int pc)
 420{
 421}
 422#endif /* CONFIG_STACKTRACE */
 423
 424extern cycle_t ftrace_now(int cpu);
 425
 426extern void trace_find_cmdline(int pid, char comm[]);
 427
 428#ifdef CONFIG_DYNAMIC_FTRACE
 429extern unsigned long ftrace_update_tot_cnt;
 430#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 431extern int DYN_FTRACE_TEST_NAME(void);
 432#endif
 433
 434extern int ring_buffer_expanded;
 435extern bool tracing_selftest_disabled;
 436DECLARE_PER_CPU(int, ftrace_cpu_disabled);
 437
 438#ifdef CONFIG_FTRACE_STARTUP_TEST
 439extern int trace_selftest_startup_function(struct tracer *trace,
 440                                           struct trace_array *tr);
 441extern int trace_selftest_startup_function_graph(struct tracer *trace,
 442                                                 struct trace_array *tr);
 443extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 444                                          struct trace_array *tr);
 445extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 446                                             struct trace_array *tr);
 447extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 448                                                 struct trace_array *tr);
 449extern int trace_selftest_startup_wakeup(struct tracer *trace,
 450                                         struct trace_array *tr);
 451extern int trace_selftest_startup_nop(struct tracer *trace,
 452                                         struct trace_array *tr);
 453extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 454                                               struct trace_array *tr);
 455extern int trace_selftest_startup_sysprof(struct tracer *trace,
 456                                               struct trace_array *tr);
 457extern int trace_selftest_startup_branch(struct tracer *trace,
 458                                         struct trace_array *tr);
 459extern int trace_selftest_startup_ksym(struct tracer *trace,
 460                                         struct trace_array *tr);
 461#endif /* CONFIG_FTRACE_STARTUP_TEST */
 462
 463extern void *head_page(struct trace_array_cpu *data);
 464extern unsigned long long ns2usecs(cycle_t nsec);
 465extern int
 466trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 467extern int
 468trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 469extern int
 470trace_array_vprintk(struct trace_array *tr,
 471                    unsigned long ip, const char *fmt, va_list args);
 472int trace_array_printk(struct trace_array *tr,
 473                       unsigned long ip, const char *fmt, ...);
 474
 475extern unsigned long trace_flags;
 476
 477extern int trace_clock_id;
 478
 479/* Standard output formatting function used for function return traces */
 480#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 481
 482/* Flag options */
 483#define TRACE_GRAPH_PRINT_OVERRUN       0x1
 484#define TRACE_GRAPH_PRINT_CPU           0x2
 485#define TRACE_GRAPH_PRINT_OVERHEAD      0x4
 486#define TRACE_GRAPH_PRINT_PROC          0x8
 487#define TRACE_GRAPH_PRINT_DURATION      0x10
 488#define TRACE_GRAPH_PRINT_ABS_TIME      0x20
 489
 490extern enum print_line_t
 491print_graph_function_flags(struct trace_iterator *iter, u32 flags);
 492extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
 493extern enum print_line_t
 494trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 495extern void graph_trace_open(struct trace_iterator *iter);
 496extern void graph_trace_close(struct trace_iterator *iter);
 497extern int __trace_graph_entry(struct trace_array *tr,
 498                               struct ftrace_graph_ent *trace,
 499                               unsigned long flags, int pc);
 500extern void __trace_graph_return(struct trace_array *tr,
 501                                 struct ftrace_graph_ret *trace,
 502                                 unsigned long flags, int pc);
 503
 504
 505#ifdef CONFIG_DYNAMIC_FTRACE
 506/* TODO: make this variable */
 507#define FTRACE_GRAPH_MAX_FUNCS          32
 508extern int ftrace_graph_filter_enabled;
 509extern int ftrace_graph_count;
 510extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 511
 512static inline int ftrace_graph_addr(unsigned long addr)
 513{
 514        int i;
 515
 516        if (!ftrace_graph_filter_enabled)
 517                return 1;
 518
 519        for (i = 0; i < ftrace_graph_count; i++) {
 520                if (addr == ftrace_graph_funcs[i])
 521                        return 1;
 522        }
 523
 524        return 0;
 525}
 526#else
 527static inline int ftrace_graph_addr(unsigned long addr)
 528{
 529        return 1;
 530}
 531#endif /* CONFIG_DYNAMIC_FTRACE */
 532#else /* CONFIG_FUNCTION_GRAPH_TRACER */
 533static inline enum print_line_t
 534print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 535{
 536        return TRACE_TYPE_UNHANDLED;
 537}
 538#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 539
 540extern struct list_head ftrace_pids;
 541
 542#ifdef CONFIG_FUNCTION_TRACER
 543static inline int ftrace_trace_task(struct task_struct *task)
 544{
 545        if (list_empty(&ftrace_pids))
 546                return 1;
 547
 548        return test_tsk_trace_trace(task);
 549}
 550#else
 551static inline int ftrace_trace_task(struct task_struct *task)
 552{
 553        return 1;
 554}
 555#endif
 556
 557/*
 558 * struct trace_parser - servers for reading the user input separated by spaces
 559 * @cont: set if the input is not complete - no final space char was found
 560 * @buffer: holds the parsed user input
 561 * @idx: user input length
 562 * @size: buffer size
 563 */
 564struct trace_parser {
 565        bool            cont;
 566        char            *buffer;
 567        unsigned        idx;
 568        unsigned        size;
 569};
 570
 571static inline bool trace_parser_loaded(struct trace_parser *parser)
 572{
 573        return (parser->idx != 0);
 574}
 575
 576static inline bool trace_parser_cont(struct trace_parser *parser)
 577{
 578        return parser->cont;
 579}
 580
 581static inline void trace_parser_clear(struct trace_parser *parser)
 582{
 583        parser->cont = false;
 584        parser->idx = 0;
 585}
 586
 587extern int trace_parser_get_init(struct trace_parser *parser, int size);
 588extern void trace_parser_put(struct trace_parser *parser);
 589extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 590        size_t cnt, loff_t *ppos);
 591
 592/*
 593 * trace_iterator_flags is an enumeration that defines bit
 594 * positions into trace_flags that controls the output.
 595 *
 596 * NOTE: These bits must match the trace_options array in
 597 *       trace.c.
 598 */
 599enum trace_iterator_flags {
 600        TRACE_ITER_PRINT_PARENT         = 0x01,
 601        TRACE_ITER_SYM_OFFSET           = 0x02,
 602        TRACE_ITER_SYM_ADDR             = 0x04,
 603        TRACE_ITER_VERBOSE              = 0x08,
 604        TRACE_ITER_RAW                  = 0x10,
 605        TRACE_ITER_HEX                  = 0x20,
 606        TRACE_ITER_BIN                  = 0x40,
 607        TRACE_ITER_BLOCK                = 0x80,
 608        TRACE_ITER_STACKTRACE           = 0x100,
 609        TRACE_ITER_PRINTK               = 0x200,
 610        TRACE_ITER_PREEMPTONLY          = 0x400,
 611        TRACE_ITER_BRANCH               = 0x800,
 612        TRACE_ITER_ANNOTATE             = 0x1000,
 613        TRACE_ITER_USERSTACKTRACE       = 0x2000,
 614        TRACE_ITER_SYM_USEROBJ          = 0x4000,
 615        TRACE_ITER_PRINTK_MSGONLY       = 0x8000,
 616        TRACE_ITER_CONTEXT_INFO         = 0x10000, /* Print pid/cpu/time */
 617        TRACE_ITER_LATENCY_FMT          = 0x20000,
 618        TRACE_ITER_SLEEP_TIME           = 0x40000,
 619        TRACE_ITER_GRAPH_TIME           = 0x80000,
 620};
 621
 622/*
 623 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 624 * control the output of kernel symbols.
 625 */
 626#define TRACE_ITER_SYM_MASK \
 627        (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 628
 629extern struct tracer nop_trace;
 630
 631/**
 632 * ftrace_preempt_disable - disable preemption scheduler safe
 633 *
 634 * When tracing can happen inside the scheduler, there exists
 635 * cases that the tracing might happen before the need_resched
 636 * flag is checked. If this happens and the tracer calls
 637 * preempt_enable (after a disable), a schedule might take place
 638 * causing an infinite recursion.
 639 *
 640 * To prevent this, we read the need_resched flag before
 641 * disabling preemption. When we want to enable preemption we
 642 * check the flag, if it is set, then we call preempt_enable_no_resched.
 643 * Otherwise, we call preempt_enable.
 644 *
 645 * The rational for doing the above is that if need_resched is set
 646 * and we have yet to reschedule, we are either in an atomic location
 647 * (where we do not need to check for scheduling) or we are inside
 648 * the scheduler and do not want to resched.
 649 */
 650static inline int ftrace_preempt_disable(void)
 651{
 652        int resched;
 653
 654        resched = need_resched();
 655        preempt_disable_notrace();
 656
 657        return resched;
 658}
 659
 660/**
 661 * ftrace_preempt_enable - enable preemption scheduler safe
 662 * @resched: the return value from ftrace_preempt_disable
 663 *
 664 * This is a scheduler safe way to enable preemption and not miss
 665 * any preemption checks. The disabled saved the state of preemption.
 666 * If resched is set, then we are either inside an atomic or
 667 * are inside the scheduler (we would have already scheduled
 668 * otherwise). In this case, we do not want to call normal
 669 * preempt_enable, but preempt_enable_no_resched instead.
 670 */
 671static inline void ftrace_preempt_enable(int resched)
 672{
 673        if (resched)
 674                preempt_enable_no_resched_notrace();
 675        else
 676                preempt_enable_notrace();
 677}
 678
 679#ifdef CONFIG_BRANCH_TRACER
 680extern int enable_branch_tracing(struct trace_array *tr);
 681extern void disable_branch_tracing(void);
 682static inline int trace_branch_enable(struct trace_array *tr)
 683{
 684        if (trace_flags & TRACE_ITER_BRANCH)
 685                return enable_branch_tracing(tr);
 686        return 0;
 687}
 688static inline void trace_branch_disable(void)
 689{
 690        /* due to races, always disable */
 691        disable_branch_tracing();
 692}
 693#else
 694static inline int trace_branch_enable(struct trace_array *tr)
 695{
 696        return 0;
 697}
 698static inline void trace_branch_disable(void)
 699{
 700}
 701#endif /* CONFIG_BRANCH_TRACER */
 702
 703/* set ring buffers to default size if not already done so */
 704int tracing_update_buffers(void);
 705
 706/* trace event type bit fields, not numeric */
 707enum {
 708        TRACE_EVENT_TYPE_PRINTF         = 1,
 709        TRACE_EVENT_TYPE_RAW            = 2,
 710};
 711
 712struct ftrace_event_field {
 713        struct list_head        link;
 714        char                    *name;
 715        char                    *type;
 716        int                     filter_type;
 717        int                     offset;
 718        int                     size;
 719        int                     is_signed;
 720};
 721
 722struct event_filter {
 723        int                     n_preds;
 724        struct filter_pred      **preds;
 725        char                    *filter_string;
 726};
 727
 728struct event_subsystem {
 729        struct list_head        list;
 730        const char              *name;
 731        struct dentry           *entry;
 732        struct event_filter     *filter;
 733        int                     nr_events;
 734};
 735
 736struct filter_pred;
 737struct regex;
 738
 739typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 740                                 int val1, int val2);
 741
 742typedef int (*regex_match_func)(char *str, struct regex *r, int len);
 743
 744enum regex_type {
 745        MATCH_FULL = 0,
 746        MATCH_FRONT_ONLY,
 747        MATCH_MIDDLE_ONLY,
 748        MATCH_END_ONLY,
 749};
 750
 751struct regex {
 752        char                    pattern[MAX_FILTER_STR_VAL];
 753        int                     len;
 754        int                     field_len;
 755        regex_match_func        match;
 756};
 757
 758struct filter_pred {
 759        filter_pred_fn_t        fn;
 760        u64                     val;
 761        struct regex            regex;
 762        char                    *field_name;
 763        int                     offset;
 764        int                     not;
 765        int                     op;
 766        int                     pop_n;
 767};
 768
 769extern enum regex_type
 770filter_parse_regex(char *buff, int len, char **search, int *not);
 771extern void print_event_filter(struct ftrace_event_call *call,
 772                               struct trace_seq *s);
 773extern int apply_event_filter(struct ftrace_event_call *call,
 774                              char *filter_string);
 775extern int apply_subsystem_event_filter(struct event_subsystem *system,
 776                                        char *filter_string);
 777extern void print_subsystem_event_filter(struct event_subsystem *system,
 778                                         struct trace_seq *s);
 779extern int filter_assign_type(const char *type);
 780
 781struct list_head *
 782trace_get_fields(struct ftrace_event_call *event_call);
 783
 784static inline int
 785filter_check_discard(struct ftrace_event_call *call, void *rec,
 786                     struct ring_buffer *buffer,
 787                     struct ring_buffer_event *event)
 788{
 789        if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
 790            !filter_match_preds(call->filter, rec)) {
 791                ring_buffer_discard_commit(buffer, event);
 792                return 1;
 793        }
 794
 795        return 0;
 796}
 797
 798extern struct mutex event_mutex;
 799extern struct list_head ftrace_events;
 800
 801extern const char *__start___trace_bprintk_fmt[];
 802extern const char *__stop___trace_bprintk_fmt[];
 803
 804#undef FTRACE_ENTRY
 805#define FTRACE_ENTRY(call, struct_name, id, tstruct, print)             \
 806        extern struct ftrace_event_call                                 \
 807        __attribute__((__aligned__(4))) event_##call;
 808#undef FTRACE_ENTRY_DUP
 809#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)         \
 810        FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 811#include "trace_entries.h"
 812
 813#endif /* _LINUX_KERNEL_TRACE_H */
 814