linux/kernel/trace/trace.h
<<
>>
Prefs
   1/* SPDX-License-Identifier: GPL-2.0 */
   2
   3#ifndef _LINUX_KERNEL_TRACE_H
   4#define _LINUX_KERNEL_TRACE_H
   5
   6#include <linux/fs.h>
   7#include <linux/atomic.h>
   8#include <linux/sched.h>
   9#include <linux/clocksource.h>
  10#include <linux/ring_buffer.h>
  11#include <linux/mmiotrace.h>
  12#include <linux/tracepoint.h>
  13#include <linux/ftrace.h>
  14#include <linux/hw_breakpoint.h>
  15#include <linux/trace_seq.h>
  16#include <linux/trace_events.h>
  17#include <linux/compiler.h>
  18#include <linux/trace_seq.h>
  19#include <linux/glob.h>
  20
  21#ifdef CONFIG_FTRACE_SYSCALLS
  22#include <asm/unistd.h>         /* For NR_SYSCALLS           */
  23#include <asm/syscall.h>        /* some archs define it here */
  24#endif
  25
  26enum trace_type {
  27        __TRACE_FIRST_TYPE = 0,
  28
  29        TRACE_FN,
  30        TRACE_CTX,
  31        TRACE_WAKE,
  32        TRACE_STACK,
  33        TRACE_PRINT,
  34        TRACE_BPRINT,
  35        TRACE_MMIO_RW,
  36        TRACE_MMIO_MAP,
  37        TRACE_BRANCH,
  38        TRACE_GRAPH_RET,
  39        TRACE_GRAPH_ENT,
  40        TRACE_USER_STACK,
  41        TRACE_BLK,
  42        TRACE_BPUTS,
  43        TRACE_HWLAT,
  44        TRACE_RAW_DATA,
  45
  46        __TRACE_LAST_TYPE,
  47};
  48
  49
  50#undef __field
  51#define __field(type, item)             type    item;
  52
  53#undef __field_struct
  54#define __field_struct(type, item)      __field(type, item)
  55
  56#undef __field_desc
  57#define __field_desc(type, container, item)
  58
  59#undef __array
  60#define __array(type, item, size)       type    item[size];
  61
  62#undef __array_desc
  63#define __array_desc(type, container, item, size)
  64
  65#undef __dynamic_array
  66#define __dynamic_array(type, item)     type    item[];
  67
  68#undef F_STRUCT
  69#define F_STRUCT(args...)               args
  70
  71#undef FTRACE_ENTRY
  72#define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)     \
  73        struct struct_name {                                            \
  74                struct trace_entry      ent;                            \
  75                tstruct                                                 \
  76        }
  77
  78#undef FTRACE_ENTRY_DUP
  79#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
  80
  81#undef FTRACE_ENTRY_REG
  82#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
  83                         filter, regfn) \
  84        FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
  85                     filter)
  86
  87#undef FTRACE_ENTRY_PACKED
  88#define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print,      \
  89                            filter)                                     \
  90        FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
  91                     filter) __packed
  92
  93#include "trace_entries.h"
  94
  95/*
  96 * syscalls are special, and need special handling, this is why
  97 * they are not included in trace_entries.h
  98 */
  99struct syscall_trace_enter {
 100        struct trace_entry      ent;
 101        int                     nr;
 102        unsigned long           args[];
 103};
 104
 105struct syscall_trace_exit {
 106        struct trace_entry      ent;
 107        int                     nr;
 108        long                    ret;
 109};
 110
 111struct kprobe_trace_entry_head {
 112        struct trace_entry      ent;
 113        unsigned long           ip;
 114};
 115
 116struct kretprobe_trace_entry_head {
 117        struct trace_entry      ent;
 118        unsigned long           func;
 119        unsigned long           ret_ip;
 120};
 121
 122/*
 123 * trace_flag_type is an enumeration that holds different
 124 * states when a trace occurs. These are:
 125 *  IRQS_OFF            - interrupts were disabled
 126 *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 127 *  NEED_RESCHED        - reschedule is requested
 128 *  HARDIRQ             - inside an interrupt handler
 129 *  SOFTIRQ             - inside a softirq handler
 130 */
 131enum trace_flag_type {
 132        TRACE_FLAG_IRQS_OFF             = 0x01,
 133        TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 134        TRACE_FLAG_NEED_RESCHED         = 0x04,
 135        TRACE_FLAG_HARDIRQ              = 0x08,
 136        TRACE_FLAG_SOFTIRQ              = 0x10,
 137        TRACE_FLAG_PREEMPT_RESCHED      = 0x20,
 138        TRACE_FLAG_NMI                  = 0x40,
 139};
 140
 141#define TRACE_BUF_SIZE          1024
 142
 143struct trace_array;
 144
 145/*
 146 * The CPU trace array - it consists of thousands of trace entries
 147 * plus some other descriptor data: (for example which task started
 148 * the trace, etc.)
 149 */
 150struct trace_array_cpu {
 151        atomic_t                disabled;
 152        void                    *buffer_page;   /* ring buffer spare */
 153
 154        unsigned long           entries;
 155        unsigned long           saved_latency;
 156        unsigned long           critical_start;
 157        unsigned long           critical_end;
 158        unsigned long           critical_sequence;
 159        unsigned long           nice;
 160        unsigned long           policy;
 161        unsigned long           rt_priority;
 162        unsigned long           skipped_entries;
 163        u64                     preempt_timestamp;
 164        pid_t                   pid;
 165        kuid_t                  uid;
 166        char                    comm[TASK_COMM_LEN];
 167
 168        bool                    ignore_pid;
 169#ifdef CONFIG_FUNCTION_TRACER
 170        bool                    ftrace_ignore_pid;
 171#endif
 172};
 173
 174struct tracer;
 175struct trace_option_dentry;
 176
 177struct trace_buffer {
 178        struct trace_array              *tr;
 179        struct ring_buffer              *buffer;
 180        struct trace_array_cpu __percpu *data;
 181        u64                             time_start;
 182        int                             cpu;
 183};
 184
 185#define TRACE_FLAGS_MAX_SIZE            32
 186
 187struct trace_options {
 188        struct tracer                   *tracer;
 189        struct trace_option_dentry      *topts;
 190};
 191
 192struct trace_pid_list {
 193        int                             pid_max;
 194        unsigned long                   *pids;
 195};
 196
 197/*
 198 * The trace array - an array of per-CPU trace arrays. This is the
 199 * highest level data structure that individual tracers deal with.
 200 * They have on/off state as well:
 201 */
 202struct trace_array {
 203        struct list_head        list;
 204        char                    *name;
 205        struct trace_buffer     trace_buffer;
 206#ifdef CONFIG_TRACER_MAX_TRACE
 207        /*
 208         * The max_buffer is used to snapshot the trace when a maximum
 209         * latency is reached, or when the user initiates a snapshot.
 210         * Some tracers will use this to store a maximum trace while
 211         * it continues examining live traces.
 212         *
 213         * The buffers for the max_buffer are set up the same as the trace_buffer
 214         * When a snapshot is taken, the buffer of the max_buffer is swapped
 215         * with the buffer of the trace_buffer and the buffers are reset for
 216         * the trace_buffer so the tracing can continue.
 217         */
 218        struct trace_buffer     max_buffer;
 219        bool                    allocated_snapshot;
 220#endif
 221#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
 222        unsigned long           max_latency;
 223#endif
 224        struct trace_pid_list   __rcu *filtered_pids;
 225        /*
 226         * max_lock is used to protect the swapping of buffers
 227         * when taking a max snapshot. The buffers themselves are
 228         * protected by per_cpu spinlocks. But the action of the swap
 229         * needs its own lock.
 230         *
 231         * This is defined as a arch_spinlock_t in order to help
 232         * with performance when lockdep debugging is enabled.
 233         *
 234         * It is also used in other places outside the update_max_tr
 235         * so it needs to be defined outside of the
 236         * CONFIG_TRACER_MAX_TRACE.
 237         */
 238        arch_spinlock_t         max_lock;
 239        int                     buffer_disabled;
 240#ifdef CONFIG_FTRACE_SYSCALLS
 241        int                     sys_refcount_enter;
 242        int                     sys_refcount_exit;
 243        struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
 244        struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
 245#endif
 246        int                     stop_count;
 247        int                     clock_id;
 248        int                     nr_topts;
 249        bool                    clear_trace;
 250        struct tracer           *current_trace;
 251        unsigned int            trace_flags;
 252        unsigned char           trace_flags_index[TRACE_FLAGS_MAX_SIZE];
 253        unsigned int            flags;
 254        raw_spinlock_t          start_lock;
 255        struct dentry           *dir;
 256        struct dentry           *options;
 257        struct dentry           *percpu_dir;
 258        struct dentry           *event_dir;
 259        struct trace_options    *topts;
 260        struct list_head        systems;
 261        struct list_head        events;
 262        cpumask_var_t           tracing_cpumask; /* only trace on set CPUs */
 263        int                     ref;
 264#ifdef CONFIG_FUNCTION_TRACER
 265        struct ftrace_ops       *ops;
 266        struct trace_pid_list   __rcu *function_pids;
 267#ifdef CONFIG_DYNAMIC_FTRACE
 268        /* All of these are protected by the ftrace_lock */
 269        struct list_head        func_probes;
 270        struct list_head        mod_trace;
 271        struct list_head        mod_notrace;
 272#endif
 273        /* function tracing enabled */
 274        int                     function_enabled;
 275#endif
 276};
 277
 278enum {
 279        TRACE_ARRAY_FL_GLOBAL   = (1 << 0)
 280};
 281
 282extern struct list_head ftrace_trace_arrays;
 283
 284extern struct mutex trace_types_lock;
 285
 286extern int trace_array_get(struct trace_array *tr);
 287extern void trace_array_put(struct trace_array *tr);
 288
 289/*
 290 * The global tracer (top) should be the first trace array added,
 291 * but we check the flag anyway.
 292 */
 293static inline struct trace_array *top_trace_array(void)
 294{
 295        struct trace_array *tr;
 296
 297        if (list_empty(&ftrace_trace_arrays))
 298                return NULL;
 299
 300        tr = list_entry(ftrace_trace_arrays.prev,
 301                        typeof(*tr), list);
 302        WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
 303        return tr;
 304}
 305
 306#define FTRACE_CMP_TYPE(var, type) \
 307        __builtin_types_compatible_p(typeof(var), type *)
 308
 309#undef IF_ASSIGN
 310#define IF_ASSIGN(var, entry, etype, id)                \
 311        if (FTRACE_CMP_TYPE(var, etype)) {              \
 312                var = (typeof(var))(entry);             \
 313                WARN_ON(id && (entry)->type != id);     \
 314                break;                                  \
 315        }
 316
 317/* Will cause compile errors if type is not found. */
 318extern void __ftrace_bad_type(void);
 319
 320/*
 321 * The trace_assign_type is a verifier that the entry type is
 322 * the same as the type being assigned. To add new types simply
 323 * add a line with the following format:
 324 *
 325 * IF_ASSIGN(var, ent, type, id);
 326 *
 327 *  Where "type" is the trace type that includes the trace_entry
 328 *  as the "ent" item. And "id" is the trace identifier that is
 329 *  used in the trace_type enum.
 330 *
 331 *  If the type can have more than one id, then use zero.
 332 */
 333#define trace_assign_type(var, ent)                                     \
 334        do {                                                            \
 335                IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 336                IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 337                IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 338                IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 339                IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 340                IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 341                IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);   \
 342                IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);   \
 343                IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
 344                IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 345                          TRACE_MMIO_RW);                               \
 346                IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 347                          TRACE_MMIO_MAP);                              \
 348                IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 349                IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 350                          TRACE_GRAPH_ENT);             \
 351                IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 352                          TRACE_GRAPH_RET);             \
 353                __ftrace_bad_type();                                    \
 354        } while (0)
 355
 356/*
 357 * An option specific to a tracer. This is a boolean value.
 358 * The bit is the bit index that sets its value on the
 359 * flags value in struct tracer_flags.
 360 */
 361struct tracer_opt {
 362        const char      *name; /* Will appear on the trace_options file */
 363        u32             bit; /* Mask assigned in val field in tracer_flags */
 364};
 365
 366/*
 367 * The set of specific options for a tracer. Your tracer
 368 * have to set the initial value of the flags val.
 369 */
 370struct tracer_flags {
 371        u32                     val;
 372        struct tracer_opt       *opts;
 373        struct tracer           *trace;
 374};
 375
 376/* Makes more easy to define a tracer opt */
 377#define TRACER_OPT(s, b)        .name = #s, .bit = b
 378
 379
 380struct trace_option_dentry {
 381        struct tracer_opt               *opt;
 382        struct tracer_flags             *flags;
 383        struct trace_array              *tr;
 384        struct dentry                   *entry;
 385};
 386
 387/**
 388 * struct tracer - a specific tracer and its callbacks to interact with tracefs
 389 * @name: the name chosen to select it on the available_tracers file
 390 * @init: called when one switches to this tracer (echo name > current_tracer)
 391 * @reset: called when one switches to another tracer
 392 * @start: called when tracing is unpaused (echo 1 > tracing_on)
 393 * @stop: called when tracing is paused (echo 0 > tracing_on)
 394 * @update_thresh: called when tracing_thresh is updated
 395 * @open: called when the trace file is opened
 396 * @pipe_open: called when the trace_pipe file is opened
 397 * @close: called when the trace file is released
 398 * @pipe_close: called when the trace_pipe file is released
 399 * @read: override the default read callback on trace_pipe
 400 * @splice_read: override the default splice_read callback on trace_pipe
 401 * @selftest: selftest to run on boot (see trace_selftest.c)
 402 * @print_headers: override the first lines that describe your columns
 403 * @print_line: callback that prints a trace
 404 * @set_flag: signals one of your private flags changed (trace_options file)
 405 * @flags: your private flags
 406 */
 407struct tracer {
 408        const char              *name;
 409        int                     (*init)(struct trace_array *tr);
 410        void                    (*reset)(struct trace_array *tr);
 411        void                    (*start)(struct trace_array *tr);
 412        void                    (*stop)(struct trace_array *tr);
 413        int                     (*update_thresh)(struct trace_array *tr);
 414        void                    (*open)(struct trace_iterator *iter);
 415        void                    (*pipe_open)(struct trace_iterator *iter);
 416        void                    (*close)(struct trace_iterator *iter);
 417        void                    (*pipe_close)(struct trace_iterator *iter);
 418        ssize_t                 (*read)(struct trace_iterator *iter,
 419                                        struct file *filp, char __user *ubuf,
 420                                        size_t cnt, loff_t *ppos);
 421        ssize_t                 (*splice_read)(struct trace_iterator *iter,
 422                                               struct file *filp,
 423                                               loff_t *ppos,
 424                                               struct pipe_inode_info *pipe,
 425                                               size_t len,
 426                                               unsigned int flags);
 427#ifdef CONFIG_FTRACE_STARTUP_TEST
 428        int                     (*selftest)(struct tracer *trace,
 429                                            struct trace_array *tr);
 430#endif
 431        void                    (*print_header)(struct seq_file *m);
 432        enum print_line_t       (*print_line)(struct trace_iterator *iter);
 433        /* If you handled the flag setting, return 0 */
 434        int                     (*set_flag)(struct trace_array *tr,
 435                                            u32 old_flags, u32 bit, int set);
 436        /* Return 0 if OK with change, else return non-zero */
 437        int                     (*flag_changed)(struct trace_array *tr,
 438                                                u32 mask, int set);
 439        struct tracer           *next;
 440        struct tracer_flags     *flags;
 441        int                     enabled;
 442        int                     ref;
 443        bool                    print_max;
 444        bool                    allow_instances;
 445#ifdef CONFIG_TRACER_MAX_TRACE
 446        bool                    use_max_tr;
 447#endif
 448        /* True if tracer cannot be enabled in kernel param */
 449        bool                    noboot;
 450};
 451
 452
 453/* Only current can touch trace_recursion */
 454
 455/*
 456 * For function tracing recursion:
 457 *  The order of these bits are important.
 458 *
 459 *  When function tracing occurs, the following steps are made:
 460 *   If arch does not support a ftrace feature:
 461 *    call internal function (uses INTERNAL bits) which calls...
 462 *   If callback is registered to the "global" list, the list
 463 *    function is called and recursion checks the GLOBAL bits.
 464 *    then this function calls...
 465 *   The function callback, which can use the FTRACE bits to
 466 *    check for recursion.
 467 *
 468 * Now if the arch does not suppport a feature, and it calls
 469 * the global list function which calls the ftrace callback
 470 * all three of these steps will do a recursion protection.
 471 * There's no reason to do one if the previous caller already
 472 * did. The recursion that we are protecting against will
 473 * go through the same steps again.
 474 *
 475 * To prevent the multiple recursion checks, if a recursion
 476 * bit is set that is higher than the MAX bit of the current
 477 * check, then we know that the check was made by the previous
 478 * caller, and we can skip the current check.
 479 */
 480enum {
 481        TRACE_BUFFER_BIT,
 482        TRACE_BUFFER_NMI_BIT,
 483        TRACE_BUFFER_IRQ_BIT,
 484        TRACE_BUFFER_SIRQ_BIT,
 485
 486        /* Start of function recursion bits */
 487        TRACE_FTRACE_BIT,
 488        TRACE_FTRACE_NMI_BIT,
 489        TRACE_FTRACE_IRQ_BIT,
 490        TRACE_FTRACE_SIRQ_BIT,
 491
 492        /* INTERNAL_BITs must be greater than FTRACE_BITs */
 493        TRACE_INTERNAL_BIT,
 494        TRACE_INTERNAL_NMI_BIT,
 495        TRACE_INTERNAL_IRQ_BIT,
 496        TRACE_INTERNAL_SIRQ_BIT,
 497
 498        TRACE_BRANCH_BIT,
 499/*
 500 * Abuse of the trace_recursion.
 501 * As we need a way to maintain state if we are tracing the function
 502 * graph in irq because we want to trace a particular function that
 503 * was called in irq context but we have irq tracing off. Since this
 504 * can only be modified by current, we can reuse trace_recursion.
 505 */
 506        TRACE_IRQ_BIT,
 507};
 508
 509#define trace_recursion_set(bit)        do { (current)->trace_recursion |= (1<<(bit)); } while (0)
 510#define trace_recursion_clear(bit)      do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
 511#define trace_recursion_test(bit)       ((current)->trace_recursion & (1<<(bit)))
 512
 513#define TRACE_CONTEXT_BITS      4
 514
 515#define TRACE_FTRACE_START      TRACE_FTRACE_BIT
 516#define TRACE_FTRACE_MAX        ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
 517
 518#define TRACE_LIST_START        TRACE_INTERNAL_BIT
 519#define TRACE_LIST_MAX          ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
 520
 521#define TRACE_CONTEXT_MASK      TRACE_LIST_MAX
 522
 523static __always_inline int trace_get_context_bit(void)
 524{
 525        int bit;
 526
 527        if (in_interrupt()) {
 528                if (in_nmi())
 529                        bit = 0;
 530
 531                else if (in_irq())
 532                        bit = 1;
 533                else
 534                        bit = 2;
 535        } else
 536                bit = 3;
 537
 538        return bit;
 539}
 540
 541static __always_inline int trace_test_and_set_recursion(int start, int max)
 542{
 543        unsigned int val = current->trace_recursion;
 544        int bit;
 545
 546        /* A previous recursion check was made */
 547        if ((val & TRACE_CONTEXT_MASK) > max)
 548                return 0;
 549
 550        bit = trace_get_context_bit() + start;
 551        if (unlikely(val & (1 << bit)))
 552                return -1;
 553
 554        val |= 1 << bit;
 555        current->trace_recursion = val;
 556        barrier();
 557
 558        return bit;
 559}
 560
 561static __always_inline void trace_clear_recursion(int bit)
 562{
 563        unsigned int val = current->trace_recursion;
 564
 565        if (!bit)
 566                return;
 567
 568        bit = 1 << bit;
 569        val &= ~bit;
 570
 571        barrier();
 572        current->trace_recursion = val;
 573}
 574
 575static inline struct ring_buffer_iter *
 576trace_buffer_iter(struct trace_iterator *iter, int cpu)
 577{
 578        if (iter->buffer_iter && iter->buffer_iter[cpu])
 579                return iter->buffer_iter[cpu];
 580        return NULL;
 581}
 582
 583int tracer_init(struct tracer *t, struct trace_array *tr);
 584int tracing_is_enabled(void);
 585void tracing_reset(struct trace_buffer *buf, int cpu);
 586void tracing_reset_online_cpus(struct trace_buffer *buf);
 587void tracing_reset_current(int cpu);
 588void tracing_reset_all_online_cpus(void);
 589int tracing_open_generic(struct inode *inode, struct file *filp);
 590bool tracing_is_disabled(void);
 591int tracer_tracing_is_on(struct trace_array *tr);
 592void tracer_tracing_on(struct trace_array *tr);
 593void tracer_tracing_off(struct trace_array *tr);
 594struct dentry *trace_create_file(const char *name,
 595                                 umode_t mode,
 596                                 struct dentry *parent,
 597                                 void *data,
 598                                 const struct file_operations *fops);
 599
 600struct dentry *tracing_init_dentry(void);
 601
 602struct ring_buffer_event;
 603
 604struct ring_buffer_event *
 605trace_buffer_lock_reserve(struct ring_buffer *buffer,
 606                          int type,
 607                          unsigned long len,
 608                          unsigned long flags,
 609                          int pc);
 610
 611struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 612                                                struct trace_array_cpu *data);
 613
 614struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 615                                          int *ent_cpu, u64 *ent_ts);
 616
 617void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
 618                                        struct ring_buffer_event *event);
 619
 620int trace_empty(struct trace_iterator *iter);
 621
 622void *trace_find_next_entry_inc(struct trace_iterator *iter);
 623
 624void trace_init_global_iter(struct trace_iterator *iter);
 625
 626void tracing_iter_reset(struct trace_iterator *iter, int cpu);
 627
 628void trace_function(struct trace_array *tr,
 629                    unsigned long ip,
 630                    unsigned long parent_ip,
 631                    unsigned long flags, int pc);
 632void trace_graph_function(struct trace_array *tr,
 633                    unsigned long ip,
 634                    unsigned long parent_ip,
 635                    unsigned long flags, int pc);
 636void trace_latency_header(struct seq_file *m);
 637void trace_default_header(struct seq_file *m);
 638void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
 639int trace_empty(struct trace_iterator *iter);
 640
 641void trace_graph_return(struct ftrace_graph_ret *trace);
 642int trace_graph_entry(struct ftrace_graph_ent *trace);
 643void set_graph_array(struct trace_array *tr);
 644
 645void tracing_start_cmdline_record(void);
 646void tracing_stop_cmdline_record(void);
 647void tracing_start_tgid_record(void);
 648void tracing_stop_tgid_record(void);
 649
 650int register_tracer(struct tracer *type);
 651int is_tracing_stopped(void);
 652
 653loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
 654
 655extern cpumask_var_t __read_mostly tracing_buffer_mask;
 656
 657#define for_each_tracing_cpu(cpu)       \
 658        for_each_cpu(cpu, tracing_buffer_mask)
 659
 660extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 661
 662extern unsigned long tracing_thresh;
 663
 664/* PID filtering */
 665
 666extern int pid_max;
 667
 668bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
 669                             pid_t search_pid);
 670bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
 671                            struct task_struct *task);
 672void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
 673                                  struct task_struct *self,
 674                                  struct task_struct *task);
 675void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
 676void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
 677int trace_pid_show(struct seq_file *m, void *v);
 678void trace_free_pid_list(struct trace_pid_list *pid_list);
 679int trace_pid_write(struct trace_pid_list *filtered_pids,
 680                    struct trace_pid_list **new_pid_list,
 681                    const char __user *ubuf, size_t cnt);
 682
 683#ifdef CONFIG_TRACER_MAX_TRACE
 684void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 685void update_max_tr_single(struct trace_array *tr,
 686                          struct task_struct *tsk, int cpu);
 687#endif /* CONFIG_TRACER_MAX_TRACE */
 688
 689#ifdef CONFIG_STACKTRACE
 690void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 691                            int pc);
 692
 693void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 694                   int pc);
 695#else
 696static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
 697                                          unsigned long flags, int pc)
 698{
 699}
 700
 701static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 702                                 int skip, int pc)
 703{
 704}
 705#endif /* CONFIG_STACKTRACE */
 706
 707extern u64 ftrace_now(int cpu);
 708
 709extern void trace_find_cmdline(int pid, char comm[]);
 710extern int trace_find_tgid(int pid);
 711extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
 712
 713#ifdef CONFIG_DYNAMIC_FTRACE
 714extern unsigned long ftrace_update_tot_cnt;
 715void ftrace_init_trace_array(struct trace_array *tr);
 716#else
 717static inline void ftrace_init_trace_array(struct trace_array *tr) { }
 718#endif
 719#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 720extern int DYN_FTRACE_TEST_NAME(void);
 721#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
 722extern int DYN_FTRACE_TEST_NAME2(void);
 723
 724extern bool ring_buffer_expanded;
 725extern bool tracing_selftest_disabled;
 726
 727#ifdef CONFIG_FTRACE_STARTUP_TEST
 728extern int trace_selftest_startup_function(struct tracer *trace,
 729                                           struct trace_array *tr);
 730extern int trace_selftest_startup_function_graph(struct tracer *trace,
 731                                                 struct trace_array *tr);
 732extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 733                                          struct trace_array *tr);
 734extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 735                                             struct trace_array *tr);
 736extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 737                                                 struct trace_array *tr);
 738extern int trace_selftest_startup_wakeup(struct tracer *trace,
 739                                         struct trace_array *tr);
 740extern int trace_selftest_startup_nop(struct tracer *trace,
 741                                         struct trace_array *tr);
 742extern int trace_selftest_startup_branch(struct tracer *trace,
 743                                         struct trace_array *tr);
 744/*
 745 * Tracer data references selftest functions that only occur
 746 * on boot up. These can be __init functions. Thus, when selftests
 747 * are enabled, then the tracers need to reference __init functions.
 748 */
 749#define __tracer_data           __refdata
 750#else
 751/* Tracers are seldom changed. Optimize when selftests are disabled. */
 752#define __tracer_data           __read_mostly
 753#endif /* CONFIG_FTRACE_STARTUP_TEST */
 754
 755extern void *head_page(struct trace_array_cpu *data);
 756extern unsigned long long ns2usecs(u64 nsec);
 757extern int
 758trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 759extern int
 760trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 761extern int
 762trace_array_vprintk(struct trace_array *tr,
 763                    unsigned long ip, const char *fmt, va_list args);
 764int trace_array_printk(struct trace_array *tr,
 765                       unsigned long ip, const char *fmt, ...);
 766int trace_array_printk_buf(struct ring_buffer *buffer,
 767                           unsigned long ip, const char *fmt, ...);
 768void trace_printk_seq(struct trace_seq *s);
 769enum print_line_t print_trace_line(struct trace_iterator *iter);
 770
 771extern char trace_find_mark(unsigned long long duration);
 772
 773struct ftrace_hash;
 774
 775struct ftrace_mod_load {
 776        struct list_head        list;
 777        char                    *func;
 778        char                    *module;
 779        int                      enable;
 780};
 781
 782enum {
 783        FTRACE_HASH_FL_MOD      = (1 << 0),
 784};
 785
 786struct ftrace_hash {
 787        unsigned long           size_bits;
 788        struct hlist_head       *buckets;
 789        unsigned long           count;
 790        unsigned long           flags;
 791        struct rcu_head         rcu;
 792};
 793
 794struct ftrace_func_entry *
 795ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
 796
 797static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
 798{
 799        return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
 800}
 801
 802/* Standard output formatting function used for function return traces */
 803#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 804
 805/* Flag options */
 806#define TRACE_GRAPH_PRINT_OVERRUN       0x1
 807#define TRACE_GRAPH_PRINT_CPU           0x2
 808#define TRACE_GRAPH_PRINT_OVERHEAD      0x4
 809#define TRACE_GRAPH_PRINT_PROC          0x8
 810#define TRACE_GRAPH_PRINT_DURATION      0x10
 811#define TRACE_GRAPH_PRINT_ABS_TIME      0x20
 812#define TRACE_GRAPH_PRINT_IRQS          0x40
 813#define TRACE_GRAPH_PRINT_TAIL          0x80
 814#define TRACE_GRAPH_SLEEP_TIME          0x100
 815#define TRACE_GRAPH_GRAPH_TIME          0x200
 816#define TRACE_GRAPH_PRINT_FILL_SHIFT    28
 817#define TRACE_GRAPH_PRINT_FILL_MASK     (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
 818
 819extern void ftrace_graph_sleep_time_control(bool enable);
 820extern void ftrace_graph_graph_time_control(bool enable);
 821
 822extern enum print_line_t
 823print_graph_function_flags(struct trace_iterator *iter, u32 flags);
 824extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
 825extern void
 826trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 827extern void graph_trace_open(struct trace_iterator *iter);
 828extern void graph_trace_close(struct trace_iterator *iter);
 829extern int __trace_graph_entry(struct trace_array *tr,
 830                               struct ftrace_graph_ent *trace,
 831                               unsigned long flags, int pc);
 832extern void __trace_graph_return(struct trace_array *tr,
 833                                 struct ftrace_graph_ret *trace,
 834                                 unsigned long flags, int pc);
 835
 836#ifdef CONFIG_DYNAMIC_FTRACE
 837extern struct ftrace_hash *ftrace_graph_hash;
 838extern struct ftrace_hash *ftrace_graph_notrace_hash;
 839
 840static inline int ftrace_graph_addr(unsigned long addr)
 841{
 842        int ret = 0;
 843
 844        preempt_disable_notrace();
 845
 846        if (ftrace_hash_empty(ftrace_graph_hash)) {
 847                ret = 1;
 848                goto out;
 849        }
 850
 851        if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
 852                /*
 853                 * If no irqs are to be traced, but a set_graph_function
 854                 * is set, and called by an interrupt handler, we still
 855                 * want to trace it.
 856                 */
 857                if (in_irq())
 858                        trace_recursion_set(TRACE_IRQ_BIT);
 859                else
 860                        trace_recursion_clear(TRACE_IRQ_BIT);
 861                ret = 1;
 862        }
 863
 864out:
 865        preempt_enable_notrace();
 866        return ret;
 867}
 868
 869static inline int ftrace_graph_notrace_addr(unsigned long addr)
 870{
 871        int ret = 0;
 872
 873        preempt_disable_notrace();
 874
 875        if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
 876                ret = 1;
 877
 878        preempt_enable_notrace();
 879        return ret;
 880}
 881#else
 882static inline int ftrace_graph_addr(unsigned long addr)
 883{
 884        return 1;
 885}
 886
 887static inline int ftrace_graph_notrace_addr(unsigned long addr)
 888{
 889        return 0;
 890}
 891#endif /* CONFIG_DYNAMIC_FTRACE */
 892
 893extern unsigned int fgraph_max_depth;
 894
 895static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
 896{
 897        /* trace it when it is-nested-in or is a function enabled. */
 898        return !(trace->depth || ftrace_graph_addr(trace->func)) ||
 899                (trace->depth < 0) ||
 900                (fgraph_max_depth && trace->depth >= fgraph_max_depth);
 901}
 902
 903#else /* CONFIG_FUNCTION_GRAPH_TRACER */
 904static inline enum print_line_t
 905print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 906{
 907        return TRACE_TYPE_UNHANDLED;
 908}
 909#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 910
 911extern struct list_head ftrace_pids;
 912
 913#ifdef CONFIG_FUNCTION_TRACER
 914struct ftrace_func_command {
 915        struct list_head        list;
 916        char                    *name;
 917        int                     (*func)(struct trace_array *tr,
 918                                        struct ftrace_hash *hash,
 919                                        char *func, char *cmd,
 920                                        char *params, int enable);
 921};
 922extern bool ftrace_filter_param __initdata;
 923static inline int ftrace_trace_task(struct trace_array *tr)
 924{
 925        return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
 926}
 927extern int ftrace_is_dead(void);
 928int ftrace_create_function_files(struct trace_array *tr,
 929                                 struct dentry *parent);
 930void ftrace_destroy_function_files(struct trace_array *tr);
 931void ftrace_init_global_array_ops(struct trace_array *tr);
 932void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
 933void ftrace_reset_array_ops(struct trace_array *tr);
 934int using_ftrace_ops_list_func(void);
 935void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
 936void ftrace_init_tracefs_toplevel(struct trace_array *tr,
 937                                  struct dentry *d_tracer);
 938void ftrace_clear_pids(struct trace_array *tr);
 939int init_function_trace(void);
 940void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
 941#else
 942static inline int ftrace_trace_task(struct trace_array *tr)
 943{
 944        return 1;
 945}
 946static inline int ftrace_is_dead(void) { return 0; }
 947static inline int
 948ftrace_create_function_files(struct trace_array *tr,
 949                             struct dentry *parent)
 950{
 951        return 0;
 952}
 953static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
 954static inline __init void
 955ftrace_init_global_array_ops(struct trace_array *tr) { }
 956static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
 957static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
 958static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
 959static inline void ftrace_clear_pids(struct trace_array *tr) { }
 960static inline int init_function_trace(void) { return 0; }
 961static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
 962/* ftace_func_t type is not defined, use macro instead of static inline */
 963#define ftrace_init_array_ops(tr, func) do { } while (0)
 964#endif /* CONFIG_FUNCTION_TRACER */
 965
 966#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
 967
 968struct ftrace_probe_ops {
 969        void                    (*func)(unsigned long ip,
 970                                        unsigned long parent_ip,
 971                                        struct trace_array *tr,
 972                                        struct ftrace_probe_ops *ops,
 973                                        void *data);
 974        int                     (*init)(struct ftrace_probe_ops *ops,
 975                                        struct trace_array *tr,
 976                                        unsigned long ip, void *init_data,
 977                                        void **data);
 978        void                    (*free)(struct ftrace_probe_ops *ops,
 979                                        struct trace_array *tr,
 980                                        unsigned long ip, void *data);
 981        int                     (*print)(struct seq_file *m,
 982                                         unsigned long ip,
 983                                         struct ftrace_probe_ops *ops,
 984                                         void *data);
 985};
 986
 987struct ftrace_func_mapper;
 988typedef int (*ftrace_mapper_func)(void *data);
 989
 990struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
 991void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
 992                                           unsigned long ip);
 993int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
 994                               unsigned long ip, void *data);
 995void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
 996                                   unsigned long ip);
 997void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
 998                             ftrace_mapper_func free_func);
 999
1000extern int
1001register_ftrace_function_probe(char *glob, struct trace_array *tr,
1002                               struct ftrace_probe_ops *ops, void *data);
1003extern int
1004unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1005                                      struct ftrace_probe_ops *ops);
1006extern void clear_ftrace_function_probes(struct trace_array *tr);
1007
1008int register_ftrace_command(struct ftrace_func_command *cmd);
1009int unregister_ftrace_command(struct ftrace_func_command *cmd);
1010
1011void ftrace_create_filter_files(struct ftrace_ops *ops,
1012                                struct dentry *parent);
1013void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1014#else
1015struct ftrace_func_command;
1016
1017static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1018{
1019        return -EINVAL;
1020}
1021static inline __init int unregister_ftrace_command(char *cmd_name)
1022{
1023        return -EINVAL;
1024}
1025static inline void clear_ftrace_function_probes(struct trace_array *tr)
1026{
1027}
1028
1029/*
1030 * The ops parameter passed in is usually undefined.
1031 * This must be a macro.
1032 */
1033#define ftrace_create_filter_files(ops, parent) do { } while (0)
1034#define ftrace_destroy_filter_files(ops) do { } while (0)
1035#endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1036
1037bool ftrace_event_is_function(struct trace_event_call *call);
1038
1039/*
1040 * struct trace_parser - servers for reading the user input separated by spaces
1041 * @cont: set if the input is not complete - no final space char was found
1042 * @buffer: holds the parsed user input
1043 * @idx: user input length
1044 * @size: buffer size
1045 */
1046struct trace_parser {
1047        bool            cont;
1048        char            *buffer;
1049        unsigned        idx;
1050        unsigned        size;
1051};
1052
1053static inline bool trace_parser_loaded(struct trace_parser *parser)
1054{
1055        return (parser->idx != 0);
1056}
1057
1058static inline bool trace_parser_cont(struct trace_parser *parser)
1059{
1060        return parser->cont;
1061}
1062
1063static inline void trace_parser_clear(struct trace_parser *parser)
1064{
1065        parser->cont = false;
1066        parser->idx = 0;
1067}
1068
1069extern int trace_parser_get_init(struct trace_parser *parser, int size);
1070extern void trace_parser_put(struct trace_parser *parser);
1071extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1072        size_t cnt, loff_t *ppos);
1073
1074/*
1075 * Only create function graph options if function graph is configured.
1076 */
1077#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1078# define FGRAPH_FLAGS                                           \
1079                C(DISPLAY_GRAPH,        "display-graph"),
1080#else
1081# define FGRAPH_FLAGS
1082#endif
1083
1084#ifdef CONFIG_BRANCH_TRACER
1085# define BRANCH_FLAGS                                   \
1086                C(BRANCH,               "branch"),
1087#else
1088# define BRANCH_FLAGS
1089#endif
1090
1091#ifdef CONFIG_FUNCTION_TRACER
1092# define FUNCTION_FLAGS                                         \
1093                C(FUNCTION,             "function-trace"),      \
1094                C(FUNC_FORK,            "function-fork"),
1095# define FUNCTION_DEFAULT_FLAGS         TRACE_ITER_FUNCTION
1096#else
1097# define FUNCTION_FLAGS
1098# define FUNCTION_DEFAULT_FLAGS         0UL
1099# define TRACE_ITER_FUNC_FORK           0UL
1100#endif
1101
1102#ifdef CONFIG_STACKTRACE
1103# define STACK_FLAGS                            \
1104                C(STACKTRACE,           "stacktrace"),
1105#else
1106# define STACK_FLAGS
1107#endif
1108
1109/*
1110 * trace_iterator_flags is an enumeration that defines bit
1111 * positions into trace_flags that controls the output.
1112 *
1113 * NOTE: These bits must match the trace_options array in
1114 *       trace.c (this macro guarantees it).
1115 */
1116#define TRACE_FLAGS                                             \
1117                C(PRINT_PARENT,         "print-parent"),        \
1118                C(SYM_OFFSET,           "sym-offset"),          \
1119                C(SYM_ADDR,             "sym-addr"),            \
1120                C(VERBOSE,              "verbose"),             \
1121                C(RAW,                  "raw"),                 \
1122                C(HEX,                  "hex"),                 \
1123                C(BIN,                  "bin"),                 \
1124                C(BLOCK,                "block"),               \
1125                C(PRINTK,               "trace_printk"),        \
1126                C(ANNOTATE,             "annotate"),            \
1127                C(USERSTACKTRACE,       "userstacktrace"),      \
1128                C(SYM_USEROBJ,          "sym-userobj"),         \
1129                C(PRINTK_MSGONLY,       "printk-msg-only"),     \
1130                C(CONTEXT_INFO,         "context-info"),   /* Print pid/cpu/time */ \
1131                C(LATENCY_FMT,          "latency-format"),      \
1132                C(RECORD_CMD,           "record-cmd"),          \
1133                C(RECORD_TGID,          "record-tgid"),         \
1134                C(OVERWRITE,            "overwrite"),           \
1135                C(STOP_ON_FREE,         "disable_on_free"),     \
1136                C(IRQ_INFO,             "irq-info"),            \
1137                C(MARKERS,              "markers"),             \
1138                C(EVENT_FORK,           "event-fork"),          \
1139                FUNCTION_FLAGS                                  \
1140                FGRAPH_FLAGS                                    \
1141                STACK_FLAGS                                     \
1142                BRANCH_FLAGS
1143
1144/*
1145 * By defining C, we can make TRACE_FLAGS a list of bit names
1146 * that will define the bits for the flag masks.
1147 */
1148#undef C
1149#define C(a, b) TRACE_ITER_##a##_BIT
1150
1151enum trace_iterator_bits {
1152        TRACE_FLAGS
1153        /* Make sure we don't go more than we have bits for */
1154        TRACE_ITER_LAST_BIT
1155};
1156
1157/*
1158 * By redefining C, we can make TRACE_FLAGS a list of masks that
1159 * use the bits as defined above.
1160 */
1161#undef C
1162#define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1163
1164enum trace_iterator_flags { TRACE_FLAGS };
1165
1166/*
1167 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1168 * control the output of kernel symbols.
1169 */
1170#define TRACE_ITER_SYM_MASK \
1171        (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1172
1173extern struct tracer nop_trace;
1174
1175#ifdef CONFIG_BRANCH_TRACER
1176extern int enable_branch_tracing(struct trace_array *tr);
1177extern void disable_branch_tracing(void);
1178static inline int trace_branch_enable(struct trace_array *tr)
1179{
1180        if (tr->trace_flags & TRACE_ITER_BRANCH)
1181                return enable_branch_tracing(tr);
1182        return 0;
1183}
1184static inline void trace_branch_disable(void)
1185{
1186        /* due to races, always disable */
1187        disable_branch_tracing();
1188}
1189#else
1190static inline int trace_branch_enable(struct trace_array *tr)
1191{
1192        return 0;
1193}
1194static inline void trace_branch_disable(void)
1195{
1196}
1197#endif /* CONFIG_BRANCH_TRACER */
1198
1199/* set ring buffers to default size if not already done so */
1200int tracing_update_buffers(void);
1201
1202struct ftrace_event_field {
1203        struct list_head        link;
1204        const char              *name;
1205        const char              *type;
1206        int                     filter_type;
1207        int                     offset;
1208        int                     size;
1209        int                     is_signed;
1210};
1211
1212struct event_filter {
1213        int                     n_preds;        /* Number assigned */
1214        int                     a_preds;        /* allocated */
1215        struct filter_pred __rcu        *preds;
1216        struct filter_pred __rcu        *root;
1217        char                            *filter_string;
1218};
1219
1220struct event_subsystem {
1221        struct list_head        list;
1222        const char              *name;
1223        struct event_filter     *filter;
1224        int                     ref_count;
1225};
1226
1227struct trace_subsystem_dir {
1228        struct list_head                list;
1229        struct event_subsystem          *subsystem;
1230        struct trace_array              *tr;
1231        struct dentry                   *entry;
1232        int                             ref_count;
1233        int                             nr_events;
1234};
1235
1236extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1237                                     struct ring_buffer *buffer,
1238                                     struct ring_buffer_event *event);
1239
1240void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1241                                     struct ring_buffer *buffer,
1242                                     struct ring_buffer_event *event,
1243                                     unsigned long flags, int pc,
1244                                     struct pt_regs *regs);
1245
1246static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1247                                              struct ring_buffer *buffer,
1248                                              struct ring_buffer_event *event,
1249                                              unsigned long flags, int pc)
1250{
1251        trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1252}
1253
1254DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1255DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1256void trace_buffered_event_disable(void);
1257void trace_buffered_event_enable(void);
1258
1259static inline void
1260__trace_event_discard_commit(struct ring_buffer *buffer,
1261                             struct ring_buffer_event *event)
1262{
1263        if (this_cpu_read(trace_buffered_event) == event) {
1264                /* Simply release the temp buffer */
1265                this_cpu_dec(trace_buffered_event_cnt);
1266                return;
1267        }
1268        ring_buffer_discard_commit(buffer, event);
1269}
1270
1271/*
1272 * Helper function for event_trigger_unlock_commit{_regs}().
1273 * If there are event triggers attached to this event that requires
1274 * filtering against its fields, then they wil be called as the
1275 * entry already holds the field information of the current event.
1276 *
1277 * It also checks if the event should be discarded or not.
1278 * It is to be discarded if the event is soft disabled and the
1279 * event was only recorded to process triggers, or if the event
1280 * filter is active and this event did not match the filters.
1281 *
1282 * Returns true if the event is discarded, false otherwise.
1283 */
1284static inline bool
1285__event_trigger_test_discard(struct trace_event_file *file,
1286                             struct ring_buffer *buffer,
1287                             struct ring_buffer_event *event,
1288                             void *entry,
1289                             enum event_trigger_type *tt)
1290{
1291        unsigned long eflags = file->flags;
1292
1293        if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1294                *tt = event_triggers_call(file, entry);
1295
1296        if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1297            (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1298             !filter_match_preds(file->filter, entry))) {
1299                __trace_event_discard_commit(buffer, event);
1300                return true;
1301        }
1302
1303        return false;
1304}
1305
1306/**
1307 * event_trigger_unlock_commit - handle triggers and finish event commit
1308 * @file: The file pointer assoctiated to the event
1309 * @buffer: The ring buffer that the event is being written to
1310 * @event: The event meta data in the ring buffer
1311 * @entry: The event itself
1312 * @irq_flags: The state of the interrupts at the start of the event
1313 * @pc: The state of the preempt count at the start of the event.
1314 *
1315 * This is a helper function to handle triggers that require data
1316 * from the event itself. It also tests the event against filters and
1317 * if the event is soft disabled and should be discarded.
1318 */
1319static inline void
1320event_trigger_unlock_commit(struct trace_event_file *file,
1321                            struct ring_buffer *buffer,
1322                            struct ring_buffer_event *event,
1323                            void *entry, unsigned long irq_flags, int pc)
1324{
1325        enum event_trigger_type tt = ETT_NONE;
1326
1327        if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1328                trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1329
1330        if (tt)
1331                event_triggers_post_call(file, tt, entry);
1332}
1333
1334/**
1335 * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1336 * @file: The file pointer assoctiated to the event
1337 * @buffer: The ring buffer that the event is being written to
1338 * @event: The event meta data in the ring buffer
1339 * @entry: The event itself
1340 * @irq_flags: The state of the interrupts at the start of the event
1341 * @pc: The state of the preempt count at the start of the event.
1342 *
1343 * This is a helper function to handle triggers that require data
1344 * from the event itself. It also tests the event against filters and
1345 * if the event is soft disabled and should be discarded.
1346 *
1347 * Same as event_trigger_unlock_commit() but calls
1348 * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1349 */
1350static inline void
1351event_trigger_unlock_commit_regs(struct trace_event_file *file,
1352                                 struct ring_buffer *buffer,
1353                                 struct ring_buffer_event *event,
1354                                 void *entry, unsigned long irq_flags, int pc,
1355                                 struct pt_regs *regs)
1356{
1357        enum event_trigger_type tt = ETT_NONE;
1358
1359        if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1360                trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1361                                                irq_flags, pc, regs);
1362
1363        if (tt)
1364                event_triggers_post_call(file, tt, entry);
1365}
1366
1367#define FILTER_PRED_INVALID     ((unsigned short)-1)
1368#define FILTER_PRED_IS_RIGHT    (1 << 15)
1369#define FILTER_PRED_FOLD        (1 << 15)
1370
1371/*
1372 * The max preds is the size of unsigned short with
1373 * two flags at the MSBs. One bit is used for both the IS_RIGHT
1374 * and FOLD flags. The other is reserved.
1375 *
1376 * 2^14 preds is way more than enough.
1377 */
1378#define MAX_FILTER_PRED         16384
1379
1380struct filter_pred;
1381struct regex;
1382
1383typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1384
1385typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1386
1387enum regex_type {
1388        MATCH_FULL = 0,
1389        MATCH_FRONT_ONLY,
1390        MATCH_MIDDLE_ONLY,
1391        MATCH_END_ONLY,
1392        MATCH_GLOB,
1393};
1394
1395struct regex {
1396        char                    pattern[MAX_FILTER_STR_VAL];
1397        int                     len;
1398        int                     field_len;
1399        regex_match_func        match;
1400};
1401
1402struct filter_pred {
1403        filter_pred_fn_t        fn;
1404        u64                     val;
1405        struct regex            regex;
1406        unsigned short          *ops;
1407        struct ftrace_event_field *field;
1408        int                     offset;
1409        int                     not;
1410        int                     op;
1411        unsigned short          index;
1412        unsigned short          parent;
1413        unsigned short          left;
1414        unsigned short          right;
1415};
1416
1417static inline bool is_string_field(struct ftrace_event_field *field)
1418{
1419        return field->filter_type == FILTER_DYN_STRING ||
1420               field->filter_type == FILTER_STATIC_STRING ||
1421               field->filter_type == FILTER_PTR_STRING ||
1422               field->filter_type == FILTER_COMM;
1423}
1424
1425static inline bool is_function_field(struct ftrace_event_field *field)
1426{
1427        return field->filter_type == FILTER_TRACE_FN;
1428}
1429
1430extern enum regex_type
1431filter_parse_regex(char *buff, int len, char **search, int *not);
1432extern void print_event_filter(struct trace_event_file *file,
1433                               struct trace_seq *s);
1434extern int apply_event_filter(struct trace_event_file *file,
1435                              char *filter_string);
1436extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1437                                        char *filter_string);
1438extern void print_subsystem_event_filter(struct event_subsystem *system,
1439                                         struct trace_seq *s);
1440extern int filter_assign_type(const char *type);
1441extern int create_event_filter(struct trace_event_call *call,
1442                               char *filter_str, bool set_str,
1443                               struct event_filter **filterp);
1444extern void free_event_filter(struct event_filter *filter);
1445
1446struct ftrace_event_field *
1447trace_find_event_field(struct trace_event_call *call, char *name);
1448
1449extern void trace_event_enable_cmd_record(bool enable);
1450extern void trace_event_enable_tgid_record(bool enable);
1451
1452extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1453extern int event_trace_del_tracer(struct trace_array *tr);
1454
1455extern struct trace_event_file *find_event_file(struct trace_array *tr,
1456                                                const char *system,
1457                                                const char *event);
1458
1459static inline void *event_file_data(struct file *filp)
1460{
1461        return READ_ONCE(file_inode(filp)->i_private);
1462}
1463
1464extern struct mutex event_mutex;
1465extern struct list_head ftrace_events;
1466
1467extern const struct file_operations event_trigger_fops;
1468extern const struct file_operations event_hist_fops;
1469
1470#ifdef CONFIG_HIST_TRIGGERS
1471extern int register_trigger_hist_cmd(void);
1472extern int register_trigger_hist_enable_disable_cmds(void);
1473#else
1474static inline int register_trigger_hist_cmd(void) { return 0; }
1475static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1476#endif
1477
1478extern int register_trigger_cmds(void);
1479extern void clear_event_triggers(struct trace_array *tr);
1480
1481struct event_trigger_data {
1482        unsigned long                   count;
1483        int                             ref;
1484        struct event_trigger_ops        *ops;
1485        struct event_command            *cmd_ops;
1486        struct event_filter __rcu       *filter;
1487        char                            *filter_str;
1488        void                            *private_data;
1489        bool                            paused;
1490        bool                            paused_tmp;
1491        struct list_head                list;
1492        char                            *name;
1493        struct list_head                named_list;
1494        struct event_trigger_data       *named_data;
1495};
1496
1497/* Avoid typos */
1498#define ENABLE_EVENT_STR        "enable_event"
1499#define DISABLE_EVENT_STR       "disable_event"
1500#define ENABLE_HIST_STR         "enable_hist"
1501#define DISABLE_HIST_STR        "disable_hist"
1502
1503struct enable_trigger_data {
1504        struct trace_event_file         *file;
1505        bool                            enable;
1506        bool                            hist;
1507};
1508
1509extern int event_enable_trigger_print(struct seq_file *m,
1510                                      struct event_trigger_ops *ops,
1511                                      struct event_trigger_data *data);
1512extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1513                                      struct event_trigger_data *data);
1514extern int event_enable_trigger_func(struct event_command *cmd_ops,
1515                                     struct trace_event_file *file,
1516                                     char *glob, char *cmd, char *param);
1517extern int event_enable_register_trigger(char *glob,
1518                                         struct event_trigger_ops *ops,
1519                                         struct event_trigger_data *data,
1520                                         struct trace_event_file *file);
1521extern void event_enable_unregister_trigger(char *glob,
1522                                            struct event_trigger_ops *ops,
1523                                            struct event_trigger_data *test,
1524                                            struct trace_event_file *file);
1525extern void trigger_data_free(struct event_trigger_data *data);
1526extern int event_trigger_init(struct event_trigger_ops *ops,
1527                              struct event_trigger_data *data);
1528extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1529                                              int trigger_enable);
1530extern void update_cond_flag(struct trace_event_file *file);
1531extern void unregister_trigger(char *glob, struct event_trigger_ops *ops,
1532                               struct event_trigger_data *test,
1533                               struct trace_event_file *file);
1534extern int set_trigger_filter(char *filter_str,
1535                              struct event_trigger_data *trigger_data,
1536                              struct trace_event_file *file);
1537extern struct event_trigger_data *find_named_trigger(const char *name);
1538extern bool is_named_trigger(struct event_trigger_data *test);
1539extern int save_named_trigger(const char *name,
1540                              struct event_trigger_data *data);
1541extern void del_named_trigger(struct event_trigger_data *data);
1542extern void pause_named_trigger(struct event_trigger_data *data);
1543extern void unpause_named_trigger(struct event_trigger_data *data);
1544extern void set_named_trigger_data(struct event_trigger_data *data,
1545                                   struct event_trigger_data *named_data);
1546extern int register_event_command(struct event_command *cmd);
1547extern int unregister_event_command(struct event_command *cmd);
1548extern int register_trigger_hist_enable_disable_cmds(void);
1549
1550/**
1551 * struct event_trigger_ops - callbacks for trace event triggers
1552 *
1553 * The methods in this structure provide per-event trigger hooks for
1554 * various trigger operations.
1555 *
1556 * All the methods below, except for @init() and @free(), must be
1557 * implemented.
1558 *
1559 * @func: The trigger 'probe' function called when the triggering
1560 *      event occurs.  The data passed into this callback is the data
1561 *      that was supplied to the event_command @reg() function that
1562 *      registered the trigger (see struct event_command) along with
1563 *      the trace record, rec.
1564 *
1565 * @init: An optional initialization function called for the trigger
1566 *      when the trigger is registered (via the event_command reg()
1567 *      function).  This can be used to perform per-trigger
1568 *      initialization such as incrementing a per-trigger reference
1569 *      count, for instance.  This is usually implemented by the
1570 *      generic utility function @event_trigger_init() (see
1571 *      trace_event_triggers.c).
1572 *
1573 * @free: An optional de-initialization function called for the
1574 *      trigger when the trigger is unregistered (via the
1575 *      event_command @reg() function).  This can be used to perform
1576 *      per-trigger de-initialization such as decrementing a
1577 *      per-trigger reference count and freeing corresponding trigger
1578 *      data, for instance.  This is usually implemented by the
1579 *      generic utility function @event_trigger_free() (see
1580 *      trace_event_triggers.c).
1581 *
1582 * @print: The callback function invoked to have the trigger print
1583 *      itself.  This is usually implemented by a wrapper function
1584 *      that calls the generic utility function @event_trigger_print()
1585 *      (see trace_event_triggers.c).
1586 */
1587struct event_trigger_ops {
1588        void                    (*func)(struct event_trigger_data *data,
1589                                        void *rec);
1590        int                     (*init)(struct event_trigger_ops *ops,
1591                                        struct event_trigger_data *data);
1592        void                    (*free)(struct event_trigger_ops *ops,
1593                                        struct event_trigger_data *data);
1594        int                     (*print)(struct seq_file *m,
1595                                         struct event_trigger_ops *ops,
1596                                         struct event_trigger_data *data);
1597};
1598
1599/**
1600 * struct event_command - callbacks and data members for event commands
1601 *
1602 * Event commands are invoked by users by writing the command name
1603 * into the 'trigger' file associated with a trace event.  The
1604 * parameters associated with a specific invocation of an event
1605 * command are used to create an event trigger instance, which is
1606 * added to the list of trigger instances associated with that trace
1607 * event.  When the event is hit, the set of triggers associated with
1608 * that event is invoked.
1609 *
1610 * The data members in this structure provide per-event command data
1611 * for various event commands.
1612 *
1613 * All the data members below, except for @post_trigger, must be set
1614 * for each event command.
1615 *
1616 * @name: The unique name that identifies the event command.  This is
1617 *      the name used when setting triggers via trigger files.
1618 *
1619 * @trigger_type: A unique id that identifies the event command
1620 *      'type'.  This value has two purposes, the first to ensure that
1621 *      only one trigger of the same type can be set at a given time
1622 *      for a particular event e.g. it doesn't make sense to have both
1623 *      a traceon and traceoff trigger attached to a single event at
1624 *      the same time, so traceon and traceoff have the same type
1625 *      though they have different names.  The @trigger_type value is
1626 *      also used as a bit value for deferring the actual trigger
1627 *      action until after the current event is finished.  Some
1628 *      commands need to do this if they themselves log to the trace
1629 *      buffer (see the @post_trigger() member below).  @trigger_type
1630 *      values are defined by adding new values to the trigger_type
1631 *      enum in include/linux/trace_events.h.
1632 *
1633 * @flags: See the enum event_command_flags below.
1634 *
1635 * All the methods below, except for @set_filter() and @unreg_all(),
1636 * must be implemented.
1637 *
1638 * @func: The callback function responsible for parsing and
1639 *      registering the trigger written to the 'trigger' file by the
1640 *      user.  It allocates the trigger instance and registers it with
1641 *      the appropriate trace event.  It makes use of the other
1642 *      event_command callback functions to orchestrate this, and is
1643 *      usually implemented by the generic utility function
1644 *      @event_trigger_callback() (see trace_event_triggers.c).
1645 *
1646 * @reg: Adds the trigger to the list of triggers associated with the
1647 *      event, and enables the event trigger itself, after
1648 *      initializing it (via the event_trigger_ops @init() function).
1649 *      This is also where commands can use the @trigger_type value to
1650 *      make the decision as to whether or not multiple instances of
1651 *      the trigger should be allowed.  This is usually implemented by
1652 *      the generic utility function @register_trigger() (see
1653 *      trace_event_triggers.c).
1654 *
1655 * @unreg: Removes the trigger from the list of triggers associated
1656 *      with the event, and disables the event trigger itself, after
1657 *      initializing it (via the event_trigger_ops @free() function).
1658 *      This is usually implemented by the generic utility function
1659 *      @unregister_trigger() (see trace_event_triggers.c).
1660 *
1661 * @unreg_all: An optional function called to remove all the triggers
1662 *      from the list of triggers associated with the event.  Called
1663 *      when a trigger file is opened in truncate mode.
1664 *
1665 * @set_filter: An optional function called to parse and set a filter
1666 *      for the trigger.  If no @set_filter() method is set for the
1667 *      event command, filters set by the user for the command will be
1668 *      ignored.  This is usually implemented by the generic utility
1669 *      function @set_trigger_filter() (see trace_event_triggers.c).
1670 *
1671 * @get_trigger_ops: The callback function invoked to retrieve the
1672 *      event_trigger_ops implementation associated with the command.
1673 */
1674struct event_command {
1675        struct list_head        list;
1676        char                    *name;
1677        enum event_trigger_type trigger_type;
1678        int                     flags;
1679        int                     (*func)(struct event_command *cmd_ops,
1680                                        struct trace_event_file *file,
1681                                        char *glob, char *cmd, char *params);
1682        int                     (*reg)(char *glob,
1683                                       struct event_trigger_ops *ops,
1684                                       struct event_trigger_data *data,
1685                                       struct trace_event_file *file);
1686        void                    (*unreg)(char *glob,
1687                                         struct event_trigger_ops *ops,
1688                                         struct event_trigger_data *data,
1689                                         struct trace_event_file *file);
1690        void                    (*unreg_all)(struct trace_event_file *file);
1691        int                     (*set_filter)(char *filter_str,
1692                                              struct event_trigger_data *data,
1693                                              struct trace_event_file *file);
1694        struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1695};
1696
1697/**
1698 * enum event_command_flags - flags for struct event_command
1699 *
1700 * @POST_TRIGGER: A flag that says whether or not this command needs
1701 *      to have its action delayed until after the current event has
1702 *      been closed.  Some triggers need to avoid being invoked while
1703 *      an event is currently in the process of being logged, since
1704 *      the trigger may itself log data into the trace buffer.  Thus
1705 *      we make sure the current event is committed before invoking
1706 *      those triggers.  To do that, the trigger invocation is split
1707 *      in two - the first part checks the filter using the current
1708 *      trace record; if a command has the @post_trigger flag set, it
1709 *      sets a bit for itself in the return value, otherwise it
1710 *      directly invokes the trigger.  Once all commands have been
1711 *      either invoked or set their return flag, the current record is
1712 *      either committed or discarded.  At that point, if any commands
1713 *      have deferred their triggers, those commands are finally
1714 *      invoked following the close of the current event.  In other
1715 *      words, if the event_trigger_ops @func() probe implementation
1716 *      itself logs to the trace buffer, this flag should be set,
1717 *      otherwise it can be left unspecified.
1718 *
1719 * @NEEDS_REC: A flag that says whether or not this command needs
1720 *      access to the trace record in order to perform its function,
1721 *      regardless of whether or not it has a filter associated with
1722 *      it (filters make a trigger require access to the trace record
1723 *      but are not always present).
1724 */
1725enum event_command_flags {
1726        EVENT_CMD_FL_POST_TRIGGER       = 1,
1727        EVENT_CMD_FL_NEEDS_REC          = 2,
1728};
1729
1730static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1731{
1732        return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1733}
1734
1735static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1736{
1737        return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1738}
1739
1740extern int trace_event_enable_disable(struct trace_event_file *file,
1741                                      int enable, int soft_disable);
1742extern int tracing_alloc_snapshot(void);
1743
1744extern const char *__start___trace_bprintk_fmt[];
1745extern const char *__stop___trace_bprintk_fmt[];
1746
1747extern const char *__start___tracepoint_str[];
1748extern const char *__stop___tracepoint_str[];
1749
1750void trace_printk_control(bool enabled);
1751void trace_printk_init_buffers(void);
1752void trace_printk_start_comm(void);
1753int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1754int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1755
1756#define MAX_EVENT_NAME_LEN      64
1757
1758extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1759extern ssize_t trace_parse_run_command(struct file *file,
1760                const char __user *buffer, size_t count, loff_t *ppos,
1761                int (*createfn)(int, char**));
1762
1763/*
1764 * Normal trace_printk() and friends allocates special buffers
1765 * to do the manipulation, as well as saves the print formats
1766 * into sections to display. But the trace infrastructure wants
1767 * to use these without the added overhead at the price of being
1768 * a bit slower (used mainly for warnings, where we don't care
1769 * about performance). The internal_trace_puts() is for such
1770 * a purpose.
1771 */
1772#define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1773
1774#undef FTRACE_ENTRY
1775#define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)     \
1776        extern struct trace_event_call                                  \
1777        __aligned(4) event_##call;
1778#undef FTRACE_ENTRY_DUP
1779#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter) \
1780        FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1781                     filter)
1782#undef FTRACE_ENTRY_PACKED
1783#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1784        FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1785                     filter)
1786
1787#include "trace_entries.h"
1788
1789#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1790int perf_ftrace_event_register(struct trace_event_call *call,
1791                               enum trace_reg type, void *data);
1792#else
1793#define perf_ftrace_event_register NULL
1794#endif
1795
1796#ifdef CONFIG_FTRACE_SYSCALLS
1797void init_ftrace_syscalls(void);
1798const char *get_syscall_name(int syscall);
1799#else
1800static inline void init_ftrace_syscalls(void) { }
1801static inline const char *get_syscall_name(int syscall)
1802{
1803        return NULL;
1804}
1805#endif
1806
1807#ifdef CONFIG_EVENT_TRACING
1808void trace_event_init(void);
1809void trace_event_eval_update(struct trace_eval_map **map, int len);
1810#else
1811static inline void __init trace_event_init(void) { }
1812static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1813#endif
1814
1815extern struct trace_iterator *tracepoint_print_iter;
1816
1817#endif /* _LINUX_KERNEL_TRACE_H */
1818