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