linux/kernel/trace/trace.h
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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
  18enum 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_SYSCALL_ENTER,
  38        TRACE_SYSCALL_EXIT,
  39        TRACE_KMEM_ALLOC,
  40        TRACE_KMEM_FREE,
  41        TRACE_POWER,
  42        TRACE_BLK,
  43
  44        __TRACE_LAST_TYPE,
  45};
  46
  47/*
  48 * Function trace entry - function address and parent function addres:
  49 */
  50struct ftrace_entry {
  51        struct trace_entry      ent;
  52        unsigned long           ip;
  53        unsigned long           parent_ip;
  54};
  55
  56/* Function call entry */
  57struct ftrace_graph_ent_entry {
  58        struct trace_entry              ent;
  59        struct ftrace_graph_ent         graph_ent;
  60};
  61
  62/* Function return entry */
  63struct ftrace_graph_ret_entry {
  64        struct trace_entry              ent;
  65        struct ftrace_graph_ret         ret;
  66};
  67extern struct tracer boot_tracer;
  68
  69/*
  70 * Context switch trace entry - which task (and prio) we switched from/to:
  71 */
  72struct ctx_switch_entry {
  73        struct trace_entry      ent;
  74        unsigned int            prev_pid;
  75        unsigned char           prev_prio;
  76        unsigned char           prev_state;
  77        unsigned int            next_pid;
  78        unsigned char           next_prio;
  79        unsigned char           next_state;
  80        unsigned int            next_cpu;
  81};
  82
  83/*
  84 * Special (free-form) trace entry:
  85 */
  86struct special_entry {
  87        struct trace_entry      ent;
  88        unsigned long           arg1;
  89        unsigned long           arg2;
  90        unsigned long           arg3;
  91};
  92
  93/*
  94 * Stack-trace entry:
  95 */
  96
  97#define FTRACE_STACK_ENTRIES    8
  98
  99struct stack_entry {
 100        struct trace_entry      ent;
 101        unsigned long           caller[FTRACE_STACK_ENTRIES];
 102};
 103
 104struct userstack_entry {
 105        struct trace_entry      ent;
 106        unsigned long           caller[FTRACE_STACK_ENTRIES];
 107};
 108
 109/*
 110 * trace_printk entry:
 111 */
 112struct bprint_entry {
 113        struct trace_entry      ent;
 114        unsigned long           ip;
 115        const char              *fmt;
 116        u32                     buf[];
 117};
 118
 119struct print_entry {
 120        struct trace_entry      ent;
 121        unsigned long           ip;
 122        char                    buf[];
 123};
 124
 125#define TRACE_OLD_SIZE          88
 126
 127struct trace_field_cont {
 128        unsigned char           type;
 129        /* Temporary till we get rid of this completely */
 130        char                    buf[TRACE_OLD_SIZE - 1];
 131};
 132
 133struct trace_mmiotrace_rw {
 134        struct trace_entry      ent;
 135        struct mmiotrace_rw     rw;
 136};
 137
 138struct trace_mmiotrace_map {
 139        struct trace_entry      ent;
 140        struct mmiotrace_map    map;
 141};
 142
 143struct trace_boot_call {
 144        struct trace_entry      ent;
 145        struct boot_trace_call boot_call;
 146};
 147
 148struct trace_boot_ret {
 149        struct trace_entry      ent;
 150        struct boot_trace_ret boot_ret;
 151};
 152
 153#define TRACE_FUNC_SIZE 30
 154#define TRACE_FILE_SIZE 20
 155struct trace_branch {
 156        struct trace_entry      ent;
 157        unsigned                line;
 158        char                    func[TRACE_FUNC_SIZE+1];
 159        char                    file[TRACE_FILE_SIZE+1];
 160        char                    correct;
 161};
 162
 163struct hw_branch_entry {
 164        struct trace_entry      ent;
 165        u64                     from;
 166        u64                     to;
 167};
 168
 169struct trace_power {
 170        struct trace_entry      ent;
 171        struct power_trace      state_data;
 172};
 173
 174enum kmemtrace_type_id {
 175        KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
 176        KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
 177        KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
 178};
 179
 180struct kmemtrace_alloc_entry {
 181        struct trace_entry      ent;
 182        enum kmemtrace_type_id type_id;
 183        unsigned long call_site;
 184        const void *ptr;
 185        size_t bytes_req;
 186        size_t bytes_alloc;
 187        gfp_t gfp_flags;
 188        int node;
 189};
 190
 191struct kmemtrace_free_entry {
 192        struct trace_entry      ent;
 193        enum kmemtrace_type_id type_id;
 194        unsigned long call_site;
 195        const void *ptr;
 196};
 197
 198struct syscall_trace_enter {
 199        struct trace_entry      ent;
 200        int                     nr;
 201        unsigned long           args[];
 202};
 203
 204struct syscall_trace_exit {
 205        struct trace_entry      ent;
 206        int                     nr;
 207        unsigned long           ret;
 208};
 209
 210
 211/*
 212 * trace_flag_type is an enumeration that holds different
 213 * states when a trace occurs. These are:
 214 *  IRQS_OFF            - interrupts were disabled
 215 *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 216 *  NEED_RESCED         - reschedule is requested
 217 *  HARDIRQ             - inside an interrupt handler
 218 *  SOFTIRQ             - inside a softirq handler
 219 */
 220enum trace_flag_type {
 221        TRACE_FLAG_IRQS_OFF             = 0x01,
 222        TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 223        TRACE_FLAG_NEED_RESCHED         = 0x04,
 224        TRACE_FLAG_HARDIRQ              = 0x08,
 225        TRACE_FLAG_SOFTIRQ              = 0x10,
 226};
 227
 228#define TRACE_BUF_SIZE          1024
 229
 230/*
 231 * The CPU trace array - it consists of thousands of trace entries
 232 * plus some other descriptor data: (for example which task started
 233 * the trace, etc.)
 234 */
 235struct trace_array_cpu {
 236        atomic_t                disabled;
 237        void                    *buffer_page;   /* ring buffer spare */
 238
 239        /* these fields get copied into max-trace: */
 240        unsigned long           trace_idx;
 241        unsigned long           overrun;
 242        unsigned long           saved_latency;
 243        unsigned long           critical_start;
 244        unsigned long           critical_end;
 245        unsigned long           critical_sequence;
 246        unsigned long           nice;
 247        unsigned long           policy;
 248        unsigned long           rt_priority;
 249        cycle_t                 preempt_timestamp;
 250        pid_t                   pid;
 251        uid_t                   uid;
 252        char                    comm[TASK_COMM_LEN];
 253};
 254
 255/*
 256 * The trace array - an array of per-CPU trace arrays. This is the
 257 * highest level data structure that individual tracers deal with.
 258 * They have on/off state as well:
 259 */
 260struct trace_array {
 261        struct ring_buffer      *buffer;
 262        unsigned long           entries;
 263        int                     cpu;
 264        cycle_t                 time_start;
 265        struct task_struct      *waiter;
 266        struct trace_array_cpu  *data[NR_CPUS];
 267};
 268
 269#define FTRACE_CMP_TYPE(var, type) \
 270        __builtin_types_compatible_p(typeof(var), type *)
 271
 272#undef IF_ASSIGN
 273#define IF_ASSIGN(var, entry, etype, id)                \
 274        if (FTRACE_CMP_TYPE(var, etype)) {              \
 275                var = (typeof(var))(entry);             \
 276                WARN_ON(id && (entry)->type != id);     \
 277                break;                                  \
 278        }
 279
 280/* Will cause compile errors if type is not found. */
 281extern void __ftrace_bad_type(void);
 282
 283/*
 284 * The trace_assign_type is a verifier that the entry type is
 285 * the same as the type being assigned. To add new types simply
 286 * add a line with the following format:
 287 *
 288 * IF_ASSIGN(var, ent, type, id);
 289 *
 290 *  Where "type" is the trace type that includes the trace_entry
 291 *  as the "ent" item. And "id" is the trace identifier that is
 292 *  used in the trace_type enum.
 293 *
 294 *  If the type can have more than one id, then use zero.
 295 */
 296#define trace_assign_type(var, ent)                                     \
 297        do {                                                            \
 298                IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 299                IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 300                IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 301                IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 302                IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 303                IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 304                IF_ASSIGN(var, ent, struct special_entry, 0);           \
 305                IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 306                          TRACE_MMIO_RW);                               \
 307                IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 308                          TRACE_MMIO_MAP);                              \
 309                IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 310                IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 311                IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 312                IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 313                          TRACE_GRAPH_ENT);             \
 314                IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 315                          TRACE_GRAPH_RET);             \
 316                IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 317                IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 318                IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 319                          TRACE_KMEM_ALLOC);    \
 320                IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 321                          TRACE_KMEM_FREE);     \
 322                IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
 323                          TRACE_SYSCALL_ENTER);                         \
 324                IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
 325                          TRACE_SYSCALL_EXIT);                          \
 326                __ftrace_bad_type();                                    \
 327        } while (0)
 328
 329/*
 330 * An option specific to a tracer. This is a boolean value.
 331 * The bit is the bit index that sets its value on the
 332 * flags value in struct tracer_flags.
 333 */
 334struct tracer_opt {
 335        const char      *name; /* Will appear on the trace_options file */
 336        u32             bit; /* Mask assigned in val field in tracer_flags */
 337};
 338
 339/*
 340 * The set of specific options for a tracer. Your tracer
 341 * have to set the initial value of the flags val.
 342 */
 343struct tracer_flags {
 344        u32                     val;
 345        struct tracer_opt       *opts;
 346};
 347
 348/* Makes more easy to define a tracer opt */
 349#define TRACER_OPT(s, b)        .name = #s, .bit = b
 350
 351
 352/**
 353 * struct tracer - a specific tracer and its callbacks to interact with debugfs
 354 * @name: the name chosen to select it on the available_tracers file
 355 * @init: called when one switches to this tracer (echo name > current_tracer)
 356 * @reset: called when one switches to another tracer
 357 * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 358 * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 359 * @open: called when the trace file is opened
 360 * @pipe_open: called when the trace_pipe file is opened
 361 * @wait_pipe: override how the user waits for traces on trace_pipe
 362 * @close: called when the trace file is released
 363 * @read: override the default read callback on trace_pipe
 364 * @splice_read: override the default splice_read callback on trace_pipe
 365 * @selftest: selftest to run on boot (see trace_selftest.c)
 366 * @print_headers: override the first lines that describe your columns
 367 * @print_line: callback that prints a trace
 368 * @set_flag: signals one of your private flags changed (trace_options file)
 369 * @flags: your private flags
 370 */
 371struct tracer {
 372        const char              *name;
 373        int                     (*init)(struct trace_array *tr);
 374        void                    (*reset)(struct trace_array *tr);
 375        void                    (*start)(struct trace_array *tr);
 376        void                    (*stop)(struct trace_array *tr);
 377        void                    (*open)(struct trace_iterator *iter);
 378        void                    (*pipe_open)(struct trace_iterator *iter);
 379        void                    (*wait_pipe)(struct trace_iterator *iter);
 380        void                    (*close)(struct trace_iterator *iter);
 381        ssize_t                 (*read)(struct trace_iterator *iter,
 382                                        struct file *filp, char __user *ubuf,
 383                                        size_t cnt, loff_t *ppos);
 384        ssize_t                 (*splice_read)(struct trace_iterator *iter,
 385                                               struct file *filp,
 386                                               loff_t *ppos,
 387                                               struct pipe_inode_info *pipe,
 388                                               size_t len,
 389                                               unsigned int flags);
 390#ifdef CONFIG_FTRACE_STARTUP_TEST
 391        int                     (*selftest)(struct tracer *trace,
 392                                            struct trace_array *tr);
 393#endif
 394        void                    (*print_header)(struct seq_file *m);
 395        enum print_line_t       (*print_line)(struct trace_iterator *iter);
 396        /* If you handled the flag setting, return 0 */
 397        int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 398        struct tracer           *next;
 399        int                     print_max;
 400        struct tracer_flags     *flags;
 401        struct tracer_stat      *stats;
 402};
 403
 404
 405#define TRACE_PIPE_ALL_CPU      -1
 406
 407int tracer_init(struct tracer *t, struct trace_array *tr);
 408int tracing_is_enabled(void);
 409void trace_wake_up(void);
 410void tracing_reset(struct trace_array *tr, int cpu);
 411void tracing_reset_online_cpus(struct trace_array *tr);
 412void tracing_reset_current(int cpu);
 413void tracing_reset_current_online_cpus(void);
 414int tracing_open_generic(struct inode *inode, struct file *filp);
 415struct dentry *trace_create_file(const char *name,
 416                                 mode_t mode,
 417                                 struct dentry *parent,
 418                                 void *data,
 419                                 const struct file_operations *fops);
 420
 421struct dentry *tracing_init_dentry(void);
 422void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 423
 424struct ring_buffer_event;
 425
 426struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
 427                                                    int type,
 428                                                    unsigned long len,
 429                                                    unsigned long flags,
 430                                                    int pc);
 431void trace_buffer_unlock_commit(struct trace_array *tr,
 432                                struct ring_buffer_event *event,
 433                                unsigned long flags, int pc);
 434
 435struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 436                                                struct trace_array_cpu *data);
 437
 438struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 439                                          int *ent_cpu, u64 *ent_ts);
 440
 441void default_wait_pipe(struct trace_iterator *iter);
 442void poll_wait_pipe(struct trace_iterator *iter);
 443
 444void ftrace(struct trace_array *tr,
 445                            struct trace_array_cpu *data,
 446                            unsigned long ip,
 447                            unsigned long parent_ip,
 448                            unsigned long flags, int pc);
 449void tracing_sched_switch_trace(struct trace_array *tr,
 450                                struct task_struct *prev,
 451                                struct task_struct *next,
 452                                unsigned long flags, int pc);
 453
 454void tracing_sched_wakeup_trace(struct trace_array *tr,
 455                                struct task_struct *wakee,
 456                                struct task_struct *cur,
 457                                unsigned long flags, int pc);
 458void trace_special(struct trace_array *tr,
 459                   struct trace_array_cpu *data,
 460                   unsigned long arg1,
 461                   unsigned long arg2,
 462                   unsigned long arg3, int pc);
 463void trace_function(struct trace_array *tr,
 464                    unsigned long ip,
 465                    unsigned long parent_ip,
 466                    unsigned long flags, int pc);
 467
 468void trace_graph_return(struct ftrace_graph_ret *trace);
 469int trace_graph_entry(struct ftrace_graph_ent *trace);
 470
 471void tracing_start_cmdline_record(void);
 472void tracing_stop_cmdline_record(void);
 473void tracing_sched_switch_assign_trace(struct trace_array *tr);
 474void tracing_stop_sched_switch_record(void);
 475void tracing_start_sched_switch_record(void);
 476int register_tracer(struct tracer *type);
 477void unregister_tracer(struct tracer *type);
 478
 479extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 480
 481extern unsigned long tracing_max_latency;
 482extern unsigned long tracing_thresh;
 483
 484void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 485void update_max_tr_single(struct trace_array *tr,
 486                          struct task_struct *tsk, int cpu);
 487
 488void __trace_stack(struct trace_array *tr,
 489                   unsigned long flags,
 490                   int skip, int pc);
 491
 492extern cycle_t ftrace_now(int cpu);
 493
 494#ifdef CONFIG_CONTEXT_SWITCH_TRACER
 495typedef void
 496(*tracer_switch_func_t)(void *private,
 497                        void *__rq,
 498                        struct task_struct *prev,
 499                        struct task_struct *next);
 500
 501struct tracer_switch_ops {
 502        tracer_switch_func_t            func;
 503        void                            *private;
 504        struct tracer_switch_ops        *next;
 505};
 506#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 507
 508extern void trace_find_cmdline(int pid, char comm[]);
 509
 510#ifdef CONFIG_DYNAMIC_FTRACE
 511extern unsigned long ftrace_update_tot_cnt;
 512#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 513extern int DYN_FTRACE_TEST_NAME(void);
 514#endif
 515
 516#ifdef CONFIG_FTRACE_STARTUP_TEST
 517extern int trace_selftest_startup_function(struct tracer *trace,
 518                                           struct trace_array *tr);
 519extern int trace_selftest_startup_function_graph(struct tracer *trace,
 520                                                 struct trace_array *tr);
 521extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 522                                          struct trace_array *tr);
 523extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 524                                             struct trace_array *tr);
 525extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 526                                                 struct trace_array *tr);
 527extern int trace_selftest_startup_wakeup(struct tracer *trace,
 528                                         struct trace_array *tr);
 529extern int trace_selftest_startup_nop(struct tracer *trace,
 530                                         struct trace_array *tr);
 531extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 532                                               struct trace_array *tr);
 533extern int trace_selftest_startup_sysprof(struct tracer *trace,
 534                                               struct trace_array *tr);
 535extern int trace_selftest_startup_branch(struct tracer *trace,
 536                                         struct trace_array *tr);
 537extern int trace_selftest_startup_hw_branches(struct tracer *trace,
 538                                              struct trace_array *tr);
 539#endif /* CONFIG_FTRACE_STARTUP_TEST */
 540
 541extern void *head_page(struct trace_array_cpu *data);
 542extern unsigned long long ns2usecs(cycle_t nsec);
 543extern int
 544trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 545extern int
 546trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 547
 548extern unsigned long trace_flags;
 549
 550/* Standard output formatting function used for function return traces */
 551#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 552extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 553extern enum print_line_t
 554trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 555
 556#ifdef CONFIG_DYNAMIC_FTRACE
 557/* TODO: make this variable */
 558#define FTRACE_GRAPH_MAX_FUNCS          32
 559extern int ftrace_graph_count;
 560extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 561
 562static inline int ftrace_graph_addr(unsigned long addr)
 563{
 564        int i;
 565
 566        if (!ftrace_graph_count || test_tsk_trace_graph(current))
 567                return 1;
 568
 569        for (i = 0; i < ftrace_graph_count; i++) {
 570                if (addr == ftrace_graph_funcs[i])
 571                        return 1;
 572        }
 573
 574        return 0;
 575}
 576#else
 577static inline int ftrace_trace_addr(unsigned long addr)
 578{
 579        return 1;
 580}
 581static inline int ftrace_graph_addr(unsigned long addr)
 582{
 583        return 1;
 584}
 585#endif /* CONFIG_DYNAMIC_FTRACE */
 586#else /* CONFIG_FUNCTION_GRAPH_TRACER */
 587static inline enum print_line_t
 588print_graph_function(struct trace_iterator *iter)
 589{
 590        return TRACE_TYPE_UNHANDLED;
 591}
 592#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 593
 594extern struct pid *ftrace_pid_trace;
 595
 596#ifdef CONFIG_FUNCTION_TRACER
 597static inline int ftrace_trace_task(struct task_struct *task)
 598{
 599        if (!ftrace_pid_trace)
 600                return 1;
 601
 602        return test_tsk_trace_trace(task);
 603}
 604#else
 605static inline int ftrace_trace_task(struct task_struct *task)
 606{
 607        return 1;
 608}
 609#endif
 610
 611/*
 612 * trace_iterator_flags is an enumeration that defines bit
 613 * positions into trace_flags that controls the output.
 614 *
 615 * NOTE: These bits must match the trace_options array in
 616 *       trace.c.
 617 */
 618enum trace_iterator_flags {
 619        TRACE_ITER_PRINT_PARENT         = 0x01,
 620        TRACE_ITER_SYM_OFFSET           = 0x02,
 621        TRACE_ITER_SYM_ADDR             = 0x04,
 622        TRACE_ITER_VERBOSE              = 0x08,
 623        TRACE_ITER_RAW                  = 0x10,
 624        TRACE_ITER_HEX                  = 0x20,
 625        TRACE_ITER_BIN                  = 0x40,
 626        TRACE_ITER_BLOCK                = 0x80,
 627        TRACE_ITER_STACKTRACE           = 0x100,
 628        TRACE_ITER_SCHED_TREE           = 0x200,
 629        TRACE_ITER_PRINTK               = 0x400,
 630        TRACE_ITER_PREEMPTONLY          = 0x800,
 631        TRACE_ITER_BRANCH               = 0x1000,
 632        TRACE_ITER_ANNOTATE             = 0x2000,
 633        TRACE_ITER_USERSTACKTRACE       = 0x4000,
 634        TRACE_ITER_SYM_USEROBJ          = 0x8000,
 635        TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 636        TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 637        TRACE_ITER_LATENCY_FMT          = 0x40000,
 638        TRACE_ITER_GLOBAL_CLK           = 0x80000,
 639        TRACE_ITER_SLEEP_TIME           = 0x100000,
 640        TRACE_ITER_GRAPH_TIME           = 0x200000,
 641};
 642
 643/*
 644 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 645 * control the output of kernel symbols.
 646 */
 647#define TRACE_ITER_SYM_MASK \
 648        (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 649
 650extern struct tracer nop_trace;
 651
 652/**
 653 * ftrace_preempt_disable - disable preemption scheduler safe
 654 *
 655 * When tracing can happen inside the scheduler, there exists
 656 * cases that the tracing might happen before the need_resched
 657 * flag is checked. If this happens and the tracer calls
 658 * preempt_enable (after a disable), a schedule might take place
 659 * causing an infinite recursion.
 660 *
 661 * To prevent this, we read the need_resched flag before
 662 * disabling preemption. When we want to enable preemption we
 663 * check the flag, if it is set, then we call preempt_enable_no_resched.
 664 * Otherwise, we call preempt_enable.
 665 *
 666 * The rational for doing the above is that if need_resched is set
 667 * and we have yet to reschedule, we are either in an atomic location
 668 * (where we do not need to check for scheduling) or we are inside
 669 * the scheduler and do not want to resched.
 670 */
 671static inline int ftrace_preempt_disable(void)
 672{
 673        int resched;
 674
 675        resched = need_resched();
 676        preempt_disable_notrace();
 677
 678        return resched;
 679}
 680
 681/**
 682 * ftrace_preempt_enable - enable preemption scheduler safe
 683 * @resched: the return value from ftrace_preempt_disable
 684 *
 685 * This is a scheduler safe way to enable preemption and not miss
 686 * any preemption checks. The disabled saved the state of preemption.
 687 * If resched is set, then we are either inside an atomic or
 688 * are inside the scheduler (we would have already scheduled
 689 * otherwise). In this case, we do not want to call normal
 690 * preempt_enable, but preempt_enable_no_resched instead.
 691 */
 692static inline void ftrace_preempt_enable(int resched)
 693{
 694        if (resched)
 695                preempt_enable_no_resched_notrace();
 696        else
 697                preempt_enable_notrace();
 698}
 699
 700#ifdef CONFIG_BRANCH_TRACER
 701extern int enable_branch_tracing(struct trace_array *tr);
 702extern void disable_branch_tracing(void);
 703static inline int trace_branch_enable(struct trace_array *tr)
 704{
 705        if (trace_flags & TRACE_ITER_BRANCH)
 706                return enable_branch_tracing(tr);
 707        return 0;
 708}
 709static inline void trace_branch_disable(void)
 710{
 711        /* due to races, always disable */
 712        disable_branch_tracing();
 713}
 714#else
 715static inline int trace_branch_enable(struct trace_array *tr)
 716{
 717        return 0;
 718}
 719static inline void trace_branch_disable(void)
 720{
 721}
 722#endif /* CONFIG_BRANCH_TRACER */
 723
 724/* set ring buffers to default size if not already done so */
 725int tracing_update_buffers(void);
 726
 727/* trace event type bit fields, not numeric */
 728enum {
 729        TRACE_EVENT_TYPE_PRINTF         = 1,
 730        TRACE_EVENT_TYPE_RAW            = 2,
 731};
 732
 733struct ftrace_event_field {
 734        struct list_head        link;
 735        char                    *name;
 736        char                    *type;
 737        int                     offset;
 738        int                     size;
 739        int                     is_signed;
 740};
 741
 742struct event_filter {
 743        int                     n_preds;
 744        struct filter_pred      **preds;
 745        char                    *filter_string;
 746};
 747
 748struct event_subsystem {
 749        struct list_head        list;
 750        const char              *name;
 751        struct dentry           *entry;
 752        void                    *filter;
 753};
 754
 755struct filter_pred;
 756
 757typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 758                                 int val1, int val2);
 759
 760struct filter_pred {
 761        filter_pred_fn_t fn;
 762        u64 val;
 763        char str_val[MAX_FILTER_STR_VAL];
 764        int str_len;
 765        char *field_name;
 766        int offset;
 767        int not;
 768        int op;
 769        int pop_n;
 770};
 771
 772extern void print_event_filter(struct ftrace_event_call *call,
 773                               struct trace_seq *s);
 774extern int apply_event_filter(struct ftrace_event_call *call,
 775                              char *filter_string);
 776extern int apply_subsystem_event_filter(struct event_subsystem *system,
 777                                        char *filter_string);
 778extern void print_subsystem_event_filter(struct event_subsystem *system,
 779                                         struct trace_seq *s);
 780
 781static inline int
 782filter_check_discard(struct ftrace_event_call *call, void *rec,
 783                     struct ring_buffer *buffer,
 784                     struct ring_buffer_event *event)
 785{
 786        if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) {
 787                ring_buffer_discard_commit(buffer, event);
 788                return 1;
 789        }
 790
 791        return 0;
 792}
 793
 794#define DEFINE_COMPARISON_PRED(type)                                    \
 795static int filter_pred_##type(struct filter_pred *pred, void *event,    \
 796                              int val1, int val2)                       \
 797{                                                                       \
 798        type *addr = (type *)(event + pred->offset);                    \
 799        type val = (type)pred->val;                                     \
 800        int match = 0;                                                  \
 801                                                                        \
 802        switch (pred->op) {                                             \
 803        case OP_LT:                                                     \
 804                match = (*addr < val);                                  \
 805                break;                                                  \
 806        case OP_LE:                                                     \
 807                match = (*addr <= val);                                 \
 808                break;                                                  \
 809        case OP_GT:                                                     \
 810                match = (*addr > val);                                  \
 811                break;                                                  \
 812        case OP_GE:                                                     \
 813                match = (*addr >= val);                                 \
 814                break;                                                  \
 815        default:                                                        \
 816                break;                                                  \
 817        }                                                               \
 818                                                                        \
 819        return match;                                                   \
 820}
 821
 822#define DEFINE_EQUALITY_PRED(size)                                      \
 823static int filter_pred_##size(struct filter_pred *pred, void *event,    \
 824                              int val1, int val2)                       \
 825{                                                                       \
 826        u##size *addr = (u##size *)(event + pred->offset);              \
 827        u##size val = (u##size)pred->val;                               \
 828        int match;                                                      \
 829                                                                        \
 830        match = (val == *addr) ^ pred->not;                             \
 831                                                                        \
 832        return match;                                                   \
 833}
 834
 835extern struct mutex event_mutex;
 836extern struct list_head ftrace_events;
 837
 838extern const char *__start___trace_bprintk_fmt[];
 839extern const char *__stop___trace_bprintk_fmt[];
 840
 841#undef TRACE_EVENT_FORMAT
 842#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
 843        extern struct ftrace_event_call event_##call;
 844#undef TRACE_EVENT_FORMAT_NOFILTER
 845#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt)
 846#include "trace_event_types.h"
 847
 848#endif /* _LINUX_KERNEL_TRACE_H */
 849
The original LXR software by the LXR community, this experimental version by lxr@linux.no.
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