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        int                     time_stamp_abs_ref;
 277        struct list_head        hist_vars;
 278};
 279
 280enum {
 281        TRACE_ARRAY_FL_GLOBAL   = (1 << 0)
 282};
 283
 284extern struct list_head ftrace_trace_arrays;
 285
 286extern struct mutex trace_types_lock;
 287
 288extern int trace_array_get(struct trace_array *tr);
 289extern void trace_array_put(struct trace_array *tr);
 290
 291extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
 292extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
 293
 294extern bool trace_clock_in_ns(struct trace_array *tr);
 295
 296/*
 297 * The global tracer (top) should be the first trace array added,
 298 * but we check the flag anyway.
 299 */
 300static inline struct trace_array *top_trace_array(void)
 301{
 302        struct trace_array *tr;
 303
 304        if (list_empty(&ftrace_trace_arrays))
 305                return NULL;
 306
 307        tr = list_entry(ftrace_trace_arrays.prev,
 308                        typeof(*tr), list);
 309        WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
 310        return tr;
 311}
 312
 313#define FTRACE_CMP_TYPE(var, type) \
 314        __builtin_types_compatible_p(typeof(var), type *)
 315
 316#undef IF_ASSIGN
 317#define IF_ASSIGN(var, entry, etype, id)                \
 318        if (FTRACE_CMP_TYPE(var, etype)) {              \
 319                var = (typeof(var))(entry);             \
 320                WARN_ON(id && (entry)->type != id);     \
 321                break;                                  \
 322        }
 323
 324/* Will cause compile errors if type is not found. */
 325extern void __ftrace_bad_type(void);
 326
 327/*
 328 * The trace_assign_type is a verifier that the entry type is
 329 * the same as the type being assigned. To add new types simply
 330 * add a line with the following format:
 331 *
 332 * IF_ASSIGN(var, ent, type, id);
 333 *
 334 *  Where "type" is the trace type that includes the trace_entry
 335 *  as the "ent" item. And "id" is the trace identifier that is
 336 *  used in the trace_type enum.
 337 *
 338 *  If the type can have more than one id, then use zero.
 339 */
 340#define trace_assign_type(var, ent)                                     \
 341        do {                                                            \
 342                IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 343                IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 344                IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 345                IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 346                IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 347                IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 348                IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);   \
 349                IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);   \
 350                IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
 351                IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 352                          TRACE_MMIO_RW);                               \
 353                IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 354                          TRACE_MMIO_MAP);                              \
 355                IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 356                IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 357                          TRACE_GRAPH_ENT);             \
 358                IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 359                          TRACE_GRAPH_RET);             \
 360                __ftrace_bad_type();                                    \
 361        } while (0)
 362
 363/*
 364 * An option specific to a tracer. This is a boolean value.
 365 * The bit is the bit index that sets its value on the
 366 * flags value in struct tracer_flags.
 367 */
 368struct tracer_opt {
 369        const char      *name; /* Will appear on the trace_options file */
 370        u32             bit; /* Mask assigned in val field in tracer_flags */
 371};
 372
 373/*
 374 * The set of specific options for a tracer. Your tracer
 375 * have to set the initial value of the flags val.
 376 */
 377struct tracer_flags {
 378        u32                     val;
 379        struct tracer_opt       *opts;
 380        struct tracer           *trace;
 381};
 382
 383/* Makes more easy to define a tracer opt */
 384#define TRACER_OPT(s, b)        .name = #s, .bit = b
 385
 386
 387struct trace_option_dentry {
 388        struct tracer_opt               *opt;
 389        struct tracer_flags             *flags;
 390        struct trace_array              *tr;
 391        struct dentry                   *entry;
 392};
 393
 394/**
 395 * struct tracer - a specific tracer and its callbacks to interact with tracefs
 396 * @name: the name chosen to select it on the available_tracers file
 397 * @init: called when one switches to this tracer (echo name > current_tracer)
 398 * @reset: called when one switches to another tracer
 399 * @start: called when tracing is unpaused (echo 1 > tracing_on)
 400 * @stop: called when tracing is paused (echo 0 > tracing_on)
 401 * @update_thresh: called when tracing_thresh is updated
 402 * @open: called when the trace file is opened
 403 * @pipe_open: called when the trace_pipe file is opened
 404 * @close: called when the trace file is released
 405 * @pipe_close: called when the trace_pipe file is released
 406 * @read: override the default read callback on trace_pipe
 407 * @splice_read: override the default splice_read callback on trace_pipe
 408 * @selftest: selftest to run on boot (see trace_selftest.c)
 409 * @print_headers: override the first lines that describe your columns
 410 * @print_line: callback that prints a trace
 411 * @set_flag: signals one of your private flags changed (trace_options file)
 412 * @flags: your private flags
 413 */
 414struct tracer {
 415        const char              *name;
 416        int                     (*init)(struct trace_array *tr);
 417        void                    (*reset)(struct trace_array *tr);
 418        void                    (*start)(struct trace_array *tr);
 419        void                    (*stop)(struct trace_array *tr);
 420        int                     (*update_thresh)(struct trace_array *tr);
 421        void                    (*open)(struct trace_iterator *iter);
 422        void                    (*pipe_open)(struct trace_iterator *iter);
 423        void                    (*close)(struct trace_iterator *iter);
 424        void                    (*pipe_close)(struct trace_iterator *iter);
 425        ssize_t                 (*read)(struct trace_iterator *iter,
 426                                        struct file *filp, char __user *ubuf,
 427                                        size_t cnt, loff_t *ppos);
 428        ssize_t                 (*splice_read)(struct trace_iterator *iter,
 429                                               struct file *filp,
 430                                               loff_t *ppos,
 431                                               struct pipe_inode_info *pipe,
 432                                               size_t len,
 433                                               unsigned int flags);
 434#ifdef CONFIG_FTRACE_STARTUP_TEST
 435        int                     (*selftest)(struct tracer *trace,
 436                                            struct trace_array *tr);
 437#endif
 438        void                    (*print_header)(struct seq_file *m);
 439        enum print_line_t       (*print_line)(struct trace_iterator *iter);
 440        /* If you handled the flag setting, return 0 */
 441        int                     (*set_flag)(struct trace_array *tr,
 442                                            u32 old_flags, u32 bit, int set);
 443        /* Return 0 if OK with change, else return non-zero */
 444        int                     (*flag_changed)(struct trace_array *tr,
 445                                                u32 mask, int set);
 446        struct tracer           *next;
 447        struct tracer_flags     *flags;
 448        int                     enabled;
 449        int                     ref;
 450        bool                    print_max;
 451        bool                    allow_instances;
 452#ifdef CONFIG_TRACER_MAX_TRACE
 453        bool                    use_max_tr;
 454#endif
 455        /* True if tracer cannot be enabled in kernel param */
 456        bool                    noboot;
 457};
 458
 459
 460/* Only current can touch trace_recursion */
 461
 462/*
 463 * For function tracing recursion:
 464 *  The order of these bits are important.
 465 *
 466 *  When function tracing occurs, the following steps are made:
 467 *   If arch does not support a ftrace feature:
 468 *    call internal function (uses INTERNAL bits) which calls...
 469 *   If callback is registered to the "global" list, the list
 470 *    function is called and recursion checks the GLOBAL bits.
 471 *    then this function calls...
 472 *   The function callback, which can use the FTRACE bits to
 473 *    check for recursion.
 474 *
 475 * Now if the arch does not suppport a feature, and it calls
 476 * the global list function which calls the ftrace callback
 477 * all three of these steps will do a recursion protection.
 478 * There's no reason to do one if the previous caller already
 479 * did. The recursion that we are protecting against will
 480 * go through the same steps again.
 481 *
 482 * To prevent the multiple recursion checks, if a recursion
 483 * bit is set that is higher than the MAX bit of the current
 484 * check, then we know that the check was made by the previous
 485 * caller, and we can skip the current check.
 486 */
 487enum {
 488        TRACE_BUFFER_BIT,
 489        TRACE_BUFFER_NMI_BIT,
 490        TRACE_BUFFER_IRQ_BIT,
 491        TRACE_BUFFER_SIRQ_BIT,
 492
 493        /* Start of function recursion bits */
 494        TRACE_FTRACE_BIT,
 495        TRACE_FTRACE_NMI_BIT,
 496        TRACE_FTRACE_IRQ_BIT,
 497        TRACE_FTRACE_SIRQ_BIT,
 498
 499        /* INTERNAL_BITs must be greater than FTRACE_BITs */
 500        TRACE_INTERNAL_BIT,
 501        TRACE_INTERNAL_NMI_BIT,
 502        TRACE_INTERNAL_IRQ_BIT,
 503        TRACE_INTERNAL_SIRQ_BIT,
 504
 505        TRACE_BRANCH_BIT,
 506/*
 507 * Abuse of the trace_recursion.
 508 * As we need a way to maintain state if we are tracing the function
 509 * graph in irq because we want to trace a particular function that
 510 * was called in irq context but we have irq tracing off. Since this
 511 * can only be modified by current, we can reuse trace_recursion.
 512 */
 513        TRACE_IRQ_BIT,
 514};
 515
 516#define trace_recursion_set(bit)        do { (current)->trace_recursion |= (1<<(bit)); } while (0)
 517#define trace_recursion_clear(bit)      do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
 518#define trace_recursion_test(bit)       ((current)->trace_recursion & (1<<(bit)))
 519
 520#define TRACE_CONTEXT_BITS      4
 521
 522#define TRACE_FTRACE_START      TRACE_FTRACE_BIT
 523#define TRACE_FTRACE_MAX        ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
 524
 525#define TRACE_LIST_START        TRACE_INTERNAL_BIT
 526#define TRACE_LIST_MAX          ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
 527
 528#define TRACE_CONTEXT_MASK      TRACE_LIST_MAX
 529
 530static __always_inline int trace_get_context_bit(void)
 531{
 532        int bit;
 533
 534        if (in_interrupt()) {
 535                if (in_nmi())
 536                        bit = 0;
 537
 538                else if (in_irq())
 539                        bit = 1;
 540                else
 541                        bit = 2;
 542        } else
 543                bit = 3;
 544
 545        return bit;
 546}
 547
 548static __always_inline int trace_test_and_set_recursion(int start, int max)
 549{
 550        unsigned int val = current->trace_recursion;
 551        int bit;
 552
 553        /* A previous recursion check was made */
 554        if ((val & TRACE_CONTEXT_MASK) > max)
 555                return 0;
 556
 557        bit = trace_get_context_bit() + start;
 558        if (unlikely(val & (1 << bit)))
 559                return -1;
 560
 561        val |= 1 << bit;
 562        current->trace_recursion = val;
 563        barrier();
 564
 565        return bit;
 566}
 567
 568static __always_inline void trace_clear_recursion(int bit)
 569{
 570        unsigned int val = current->trace_recursion;
 571
 572        if (!bit)
 573                return;
 574
 575        bit = 1 << bit;
 576        val &= ~bit;
 577
 578        barrier();
 579        current->trace_recursion = val;
 580}
 581
 582static inline struct ring_buffer_iter *
 583trace_buffer_iter(struct trace_iterator *iter, int cpu)
 584{
 585        if (iter->buffer_iter && iter->buffer_iter[cpu])
 586                return iter->buffer_iter[cpu];
 587        return NULL;
 588}
 589
 590int tracer_init(struct tracer *t, struct trace_array *tr);
 591int tracing_is_enabled(void);
 592void tracing_reset(struct trace_buffer *buf, int cpu);
 593void tracing_reset_online_cpus(struct trace_buffer *buf);
 594void tracing_reset_current(int cpu);
 595void tracing_reset_all_online_cpus(void);
 596int tracing_open_generic(struct inode *inode, struct file *filp);
 597bool tracing_is_disabled(void);
 598int tracer_tracing_is_on(struct trace_array *tr);
 599void tracer_tracing_on(struct trace_array *tr);
 600void tracer_tracing_off(struct trace_array *tr);
 601struct dentry *trace_create_file(const char *name,
 602                                 umode_t mode,
 603                                 struct dentry *parent,
 604                                 void *data,
 605                                 const struct file_operations *fops);
 606
 607struct dentry *tracing_init_dentry(void);
 608
 609struct ring_buffer_event;
 610
 611struct ring_buffer_event *
 612trace_buffer_lock_reserve(struct ring_buffer *buffer,
 613                          int type,
 614                          unsigned long len,
 615                          unsigned long flags,
 616                          int pc);
 617
 618struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 619                                                struct trace_array_cpu *data);
 620
 621struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 622                                          int *ent_cpu, u64 *ent_ts);
 623
 624void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
 625                                        struct ring_buffer_event *event);
 626
 627int trace_empty(struct trace_iterator *iter);
 628
 629void *trace_find_next_entry_inc(struct trace_iterator *iter);
 630
 631void trace_init_global_iter(struct trace_iterator *iter);
 632
 633void tracing_iter_reset(struct trace_iterator *iter, int cpu);
 634
 635void trace_function(struct trace_array *tr,
 636                    unsigned long ip,
 637                    unsigned long parent_ip,
 638                    unsigned long flags, int pc);
 639void trace_graph_function(struct trace_array *tr,
 640                    unsigned long ip,
 641                    unsigned long parent_ip,
 642                    unsigned long flags, int pc);
 643void trace_latency_header(struct seq_file *m);
 644void trace_default_header(struct seq_file *m);
 645void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
 646int trace_empty(struct trace_iterator *iter);
 647
 648void trace_graph_return(struct ftrace_graph_ret *trace);
 649int trace_graph_entry(struct ftrace_graph_ent *trace);
 650void set_graph_array(struct trace_array *tr);
 651
 652void tracing_start_cmdline_record(void);
 653void tracing_stop_cmdline_record(void);
 654void tracing_start_tgid_record(void);
 655void tracing_stop_tgid_record(void);
 656
 657int register_tracer(struct tracer *type);
 658int is_tracing_stopped(void);
 659
 660loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
 661
 662extern cpumask_var_t __read_mostly tracing_buffer_mask;
 663
 664#define for_each_tracing_cpu(cpu)       \
 665        for_each_cpu(cpu, tracing_buffer_mask)
 666
 667extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 668
 669extern unsigned long tracing_thresh;
 670
 671/* PID filtering */
 672
 673extern int pid_max;
 674
 675bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
 676                             pid_t search_pid);
 677bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
 678                            struct task_struct *task);
 679void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
 680                                  struct task_struct *self,
 681                                  struct task_struct *task);
 682void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
 683void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
 684int trace_pid_show(struct seq_file *m, void *v);
 685void trace_free_pid_list(struct trace_pid_list *pid_list);
 686int trace_pid_write(struct trace_pid_list *filtered_pids,
 687                    struct trace_pid_list **new_pid_list,
 688                    const char __user *ubuf, size_t cnt);
 689
 690#ifdef CONFIG_TRACER_MAX_TRACE
 691void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 692void update_max_tr_single(struct trace_array *tr,
 693                          struct task_struct *tsk, int cpu);
 694#endif /* CONFIG_TRACER_MAX_TRACE */
 695
 696#ifdef CONFIG_STACKTRACE
 697void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 698                            int pc);
 699
 700void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 701                   int pc);
 702#else
 703static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
 704                                          unsigned long flags, int pc)
 705{
 706}
 707
 708static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 709                                 int skip, int pc)
 710{
 711}
 712#endif /* CONFIG_STACKTRACE */
 713
 714extern u64 ftrace_now(int cpu);
 715
 716extern void trace_find_cmdline(int pid, char comm[]);
 717extern int trace_find_tgid(int pid);
 718extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
 719
 720#ifdef CONFIG_DYNAMIC_FTRACE
 721extern unsigned long ftrace_update_tot_cnt;
 722void ftrace_init_trace_array(struct trace_array *tr);
 723#else
 724static inline void ftrace_init_trace_array(struct trace_array *tr) { }
 725#endif
 726#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 727extern int DYN_FTRACE_TEST_NAME(void);
 728#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
 729extern int DYN_FTRACE_TEST_NAME2(void);
 730
 731extern bool ring_buffer_expanded;
 732extern bool tracing_selftest_disabled;
 733
 734#ifdef CONFIG_FTRACE_STARTUP_TEST
 735extern int trace_selftest_startup_function(struct tracer *trace,
 736                                           struct trace_array *tr);
 737extern int trace_selftest_startup_function_graph(struct tracer *trace,
 738                                                 struct trace_array *tr);
 739extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 740                                          struct trace_array *tr);
 741extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 742                                             struct trace_array *tr);
 743extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 744                                                 struct trace_array *tr);
 745extern int trace_selftest_startup_wakeup(struct tracer *trace,
 746                                         struct trace_array *tr);
 747extern int trace_selftest_startup_nop(struct tracer *trace,
 748                                         struct trace_array *tr);
 749extern int trace_selftest_startup_branch(struct tracer *trace,
 750                                         struct trace_array *tr);
 751/*
 752 * Tracer data references selftest functions that only occur
 753 * on boot up. These can be __init functions. Thus, when selftests
 754 * are enabled, then the tracers need to reference __init functions.
 755 */
 756#define __tracer_data           __refdata
 757#else
 758/* Tracers are seldom changed. Optimize when selftests are disabled. */
 759#define __tracer_data           __read_mostly
 760#endif /* CONFIG_FTRACE_STARTUP_TEST */
 761
 762extern void *head_page(struct trace_array_cpu *data);
 763extern unsigned long long ns2usecs(u64 nsec);
 764extern int
 765trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 766extern int
 767trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 768extern int
 769trace_array_vprintk(struct trace_array *tr,
 770                    unsigned long ip, const char *fmt, va_list args);
 771int trace_array_printk(struct trace_array *tr,
 772                       unsigned long ip, const char *fmt, ...);
 773int trace_array_printk_buf(struct ring_buffer *buffer,
 774                           unsigned long ip, const char *fmt, ...);
 775void trace_printk_seq(struct trace_seq *s);
 776enum print_line_t print_trace_line(struct trace_iterator *iter);
 777
 778extern char trace_find_mark(unsigned long long duration);
 779
 780struct ftrace_hash;
 781
 782struct ftrace_mod_load {
 783        struct list_head        list;
 784        char                    *func;
 785        char                    *module;
 786        int                      enable;
 787};
 788
 789enum {
 790        FTRACE_HASH_FL_MOD      = (1 << 0),
 791};
 792
 793struct ftrace_hash {
 794        unsigned long           size_bits;
 795        struct hlist_head       *buckets;
 796        unsigned long           count;
 797        unsigned long           flags;
 798        struct rcu_head         rcu;
 799};
 800
 801struct ftrace_func_entry *
 802ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
 803
 804static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
 805{
 806        return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
 807}
 808
 809/* Standard output formatting function used for function return traces */
 810#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 811
 812/* Flag options */
 813#define TRACE_GRAPH_PRINT_OVERRUN       0x1
 814#define TRACE_GRAPH_PRINT_CPU           0x2
 815#define TRACE_GRAPH_PRINT_OVERHEAD      0x4
 816#define TRACE_GRAPH_PRINT_PROC          0x8
 817#define TRACE_GRAPH_PRINT_DURATION      0x10
 818#define TRACE_GRAPH_PRINT_ABS_TIME      0x20
 819#define TRACE_GRAPH_PRINT_IRQS          0x40
 820#define TRACE_GRAPH_PRINT_TAIL          0x80
 821#define TRACE_GRAPH_SLEEP_TIME          0x100
 822#define TRACE_GRAPH_GRAPH_TIME          0x200
 823#define TRACE_GRAPH_PRINT_FILL_SHIFT    28
 824#define TRACE_GRAPH_PRINT_FILL_MASK     (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
 825
 826extern void ftrace_graph_sleep_time_control(bool enable);
 827extern void ftrace_graph_graph_time_control(bool enable);
 828
 829extern enum print_line_t
 830print_graph_function_flags(struct trace_iterator *iter, u32 flags);
 831extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
 832extern void
 833trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 834extern void graph_trace_open(struct trace_iterator *iter);
 835extern void graph_trace_close(struct trace_iterator *iter);
 836extern int __trace_graph_entry(struct trace_array *tr,
 837                               struct ftrace_graph_ent *trace,
 838                               unsigned long flags, int pc);
 839extern void __trace_graph_return(struct trace_array *tr,
 840                                 struct ftrace_graph_ret *trace,
 841                                 unsigned long flags, int pc);
 842
 843#ifdef CONFIG_DYNAMIC_FTRACE
 844extern struct ftrace_hash *ftrace_graph_hash;
 845extern struct ftrace_hash *ftrace_graph_notrace_hash;
 846
 847static inline int ftrace_graph_addr(unsigned long addr)
 848{
 849        int ret = 0;
 850
 851        preempt_disable_notrace();
 852
 853        if (ftrace_hash_empty(ftrace_graph_hash)) {
 854                ret = 1;
 855                goto out;
 856        }
 857
 858        if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
 859                /*
 860                 * If no irqs are to be traced, but a set_graph_function
 861                 * is set, and called by an interrupt handler, we still
 862                 * want to trace it.
 863                 */
 864                if (in_irq())
 865                        trace_recursion_set(TRACE_IRQ_BIT);
 866                else
 867                        trace_recursion_clear(TRACE_IRQ_BIT);
 868                ret = 1;
 869        }
 870
 871out:
 872        preempt_enable_notrace();
 873        return ret;
 874}
 875
 876static inline int ftrace_graph_notrace_addr(unsigned long addr)
 877{
 878        int ret = 0;
 879
 880        preempt_disable_notrace();
 881
 882        if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
 883                ret = 1;
 884
 885        preempt_enable_notrace();
 886        return ret;
 887}
 888#else
 889static inline int ftrace_graph_addr(unsigned long addr)
 890{
 891        return 1;
 892}
 893
 894static inline int ftrace_graph_notrace_addr(unsigned long addr)
 895{
 896        return 0;
 897}
 898#endif /* CONFIG_DYNAMIC_FTRACE */
 899
 900extern unsigned int fgraph_max_depth;
 901
 902static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
 903{
 904        /* trace it when it is-nested-in or is a function enabled. */
 905        return !(trace->depth || ftrace_graph_addr(trace->func)) ||
 906                (trace->depth < 0) ||
 907                (fgraph_max_depth && trace->depth >= fgraph_max_depth);
 908}
 909
 910#else /* CONFIG_FUNCTION_GRAPH_TRACER */
 911static inline enum print_line_t
 912print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 913{
 914        return TRACE_TYPE_UNHANDLED;
 915}
 916#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 917
 918extern struct list_head ftrace_pids;
 919
 920#ifdef CONFIG_FUNCTION_TRACER
 921struct ftrace_func_command {
 922        struct list_head        list;
 923        char                    *name;
 924        int                     (*func)(struct trace_array *tr,
 925                                        struct ftrace_hash *hash,
 926                                        char *func, char *cmd,
 927                                        char *params, int enable);
 928};
 929extern bool ftrace_filter_param __initdata;
 930static inline int ftrace_trace_task(struct trace_array *tr)
 931{
 932        return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
 933}
 934extern int ftrace_is_dead(void);
 935int ftrace_create_function_files(struct trace_array *tr,
 936                                 struct dentry *parent);
 937void ftrace_destroy_function_files(struct trace_array *tr);
 938void ftrace_init_global_array_ops(struct trace_array *tr);
 939void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
 940void ftrace_reset_array_ops(struct trace_array *tr);
 941int using_ftrace_ops_list_func(void);
 942void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
 943void ftrace_init_tracefs_toplevel(struct trace_array *tr,
 944                                  struct dentry *d_tracer);
 945void ftrace_clear_pids(struct trace_array *tr);
 946int init_function_trace(void);
 947void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
 948#else
 949static inline int ftrace_trace_task(struct trace_array *tr)
 950{
 951        return 1;
 952}
 953static inline int ftrace_is_dead(void) { return 0; }
 954static inline int
 955ftrace_create_function_files(struct trace_array *tr,
 956                             struct dentry *parent)
 957{
 958        return 0;
 959}
 960static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
 961static inline __init void
 962ftrace_init_global_array_ops(struct trace_array *tr) { }
 963static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
 964static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
 965static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
 966static inline void ftrace_clear_pids(struct trace_array *tr) { }
 967static inline int init_function_trace(void) { return 0; }
 968static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
 969/* ftace_func_t type is not defined, use macro instead of static inline */
 970#define ftrace_init_array_ops(tr, func) do { } while (0)
 971#endif /* CONFIG_FUNCTION_TRACER */
 972
 973#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
 974
 975struct ftrace_probe_ops {
 976        void                    (*func)(unsigned long ip,
 977                                        unsigned long parent_ip,
 978                                        struct trace_array *tr,
 979                                        struct ftrace_probe_ops *ops,
 980                                        void *data);
 981        int                     (*init)(struct ftrace_probe_ops *ops,
 982                                        struct trace_array *tr,
 983                                        unsigned long ip, void *init_data,
 984                                        void **data);
 985        void                    (*free)(struct ftrace_probe_ops *ops,
 986                                        struct trace_array *tr,
 987                                        unsigned long ip, void *data);
 988        int                     (*print)(struct seq_file *m,
 989                                         unsigned long ip,
 990                                         struct ftrace_probe_ops *ops,
 991                                         void *data);
 992};
 993
 994struct ftrace_func_mapper;
 995typedef int (*ftrace_mapper_func)(void *data);
 996
 997struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
 998void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
 999                                           unsigned long ip);
1000int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
1001                               unsigned long ip, void *data);
1002void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
1003                                   unsigned long ip);
1004void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
1005                             ftrace_mapper_func free_func);
1006
1007extern int
1008register_ftrace_function_probe(char *glob, struct trace_array *tr,
1009                               struct ftrace_probe_ops *ops, void *data);
1010extern int
1011unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
1012                                      struct ftrace_probe_ops *ops);
1013extern void clear_ftrace_function_probes(struct trace_array *tr);
1014
1015int register_ftrace_command(struct ftrace_func_command *cmd);
1016int unregister_ftrace_command(struct ftrace_func_command *cmd);
1017
1018void ftrace_create_filter_files(struct ftrace_ops *ops,
1019                                struct dentry *parent);
1020void ftrace_destroy_filter_files(struct ftrace_ops *ops);
1021#else
1022struct ftrace_func_command;
1023
1024static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
1025{
1026        return -EINVAL;
1027}
1028static inline __init int unregister_ftrace_command(char *cmd_name)
1029{
1030        return -EINVAL;
1031}
1032static inline void clear_ftrace_function_probes(struct trace_array *tr)
1033{
1034}
1035
1036/*
1037 * The ops parameter passed in is usually undefined.
1038 * This must be a macro.
1039 */
1040#define ftrace_create_filter_files(ops, parent) do { } while (0)
1041#define ftrace_destroy_filter_files(ops) do { } while (0)
1042#endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
1043
1044bool ftrace_event_is_function(struct trace_event_call *call);
1045
1046/*
1047 * struct trace_parser - servers for reading the user input separated by spaces
1048 * @cont: set if the input is not complete - no final space char was found
1049 * @buffer: holds the parsed user input
1050 * @idx: user input length
1051 * @size: buffer size
1052 */
1053struct trace_parser {
1054        bool            cont;
1055        char            *buffer;
1056        unsigned        idx;
1057        unsigned        size;
1058};
1059
1060static inline bool trace_parser_loaded(struct trace_parser *parser)
1061{
1062        return (parser->idx != 0);
1063}
1064
1065static inline bool trace_parser_cont(struct trace_parser *parser)
1066{
1067        return parser->cont;
1068}
1069
1070static inline void trace_parser_clear(struct trace_parser *parser)
1071{
1072        parser->cont = false;
1073        parser->idx = 0;
1074}
1075
1076extern int trace_parser_get_init(struct trace_parser *parser, int size);
1077extern void trace_parser_put(struct trace_parser *parser);
1078extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
1079        size_t cnt, loff_t *ppos);
1080
1081/*
1082 * Only create function graph options if function graph is configured.
1083 */
1084#ifdef CONFIG_FUNCTION_GRAPH_TRACER
1085# define FGRAPH_FLAGS                                           \
1086                C(DISPLAY_GRAPH,        "display-graph"),
1087#else
1088# define FGRAPH_FLAGS
1089#endif
1090
1091#ifdef CONFIG_BRANCH_TRACER
1092# define BRANCH_FLAGS                                   \
1093                C(BRANCH,               "branch"),
1094#else
1095# define BRANCH_FLAGS
1096#endif
1097
1098#ifdef CONFIG_FUNCTION_TRACER
1099# define FUNCTION_FLAGS                                         \
1100                C(FUNCTION,             "function-trace"),      \
1101                C(FUNC_FORK,            "function-fork"),
1102# define FUNCTION_DEFAULT_FLAGS         TRACE_ITER_FUNCTION
1103#else
1104# define FUNCTION_FLAGS
1105# define FUNCTION_DEFAULT_FLAGS         0UL
1106# define TRACE_ITER_FUNC_FORK           0UL
1107#endif
1108
1109#ifdef CONFIG_STACKTRACE
1110# define STACK_FLAGS                            \
1111                C(STACKTRACE,           "stacktrace"),
1112#else
1113# define STACK_FLAGS
1114#endif
1115
1116/*
1117 * trace_iterator_flags is an enumeration that defines bit
1118 * positions into trace_flags that controls the output.
1119 *
1120 * NOTE: These bits must match the trace_options array in
1121 *       trace.c (this macro guarantees it).
1122 */
1123#define TRACE_FLAGS                                             \
1124                C(PRINT_PARENT,         "print-parent"),        \
1125                C(SYM_OFFSET,           "sym-offset"),          \
1126                C(SYM_ADDR,             "sym-addr"),            \
1127                C(VERBOSE,              "verbose"),             \
1128                C(RAW,                  "raw"),                 \
1129                C(HEX,                  "hex"),                 \
1130                C(BIN,                  "bin"),                 \
1131                C(BLOCK,                "block"),               \
1132                C(PRINTK,               "trace_printk"),        \
1133                C(ANNOTATE,             "annotate"),            \
1134                C(USERSTACKTRACE,       "userstacktrace"),      \
1135                C(SYM_USEROBJ,          "sym-userobj"),         \
1136                C(PRINTK_MSGONLY,       "printk-msg-only"),     \
1137                C(CONTEXT_INFO,         "context-info"),   /* Print pid/cpu/time */ \
1138                C(LATENCY_FMT,          "latency-format"),      \
1139                C(RECORD_CMD,           "record-cmd"),          \
1140                C(RECORD_TGID,          "record-tgid"),         \
1141                C(OVERWRITE,            "overwrite"),           \
1142                C(STOP_ON_FREE,         "disable_on_free"),     \
1143                C(IRQ_INFO,             "irq-info"),            \
1144                C(MARKERS,              "markers"),             \
1145                C(EVENT_FORK,           "event-fork"),          \
1146                FUNCTION_FLAGS                                  \
1147                FGRAPH_FLAGS                                    \
1148                STACK_FLAGS                                     \
1149                BRANCH_FLAGS
1150
1151/*
1152 * By defining C, we can make TRACE_FLAGS a list of bit names
1153 * that will define the bits for the flag masks.
1154 */
1155#undef C
1156#define C(a, b) TRACE_ITER_##a##_BIT
1157
1158enum trace_iterator_bits {
1159        TRACE_FLAGS
1160        /* Make sure we don't go more than we have bits for */
1161        TRACE_ITER_LAST_BIT
1162};
1163
1164/*
1165 * By redefining C, we can make TRACE_FLAGS a list of masks that
1166 * use the bits as defined above.
1167 */
1168#undef C
1169#define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
1170
1171enum trace_iterator_flags { TRACE_FLAGS };
1172
1173/*
1174 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
1175 * control the output of kernel symbols.
1176 */
1177#define TRACE_ITER_SYM_MASK \
1178        (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
1179
1180extern struct tracer nop_trace;
1181
1182#ifdef CONFIG_BRANCH_TRACER
1183extern int enable_branch_tracing(struct trace_array *tr);
1184extern void disable_branch_tracing(void);
1185static inline int trace_branch_enable(struct trace_array *tr)
1186{
1187        if (tr->trace_flags & TRACE_ITER_BRANCH)
1188                return enable_branch_tracing(tr);
1189        return 0;
1190}
1191static inline void trace_branch_disable(void)
1192{
1193        /* due to races, always disable */
1194        disable_branch_tracing();
1195}
1196#else
1197static inline int trace_branch_enable(struct trace_array *tr)
1198{
1199        return 0;
1200}
1201static inline void trace_branch_disable(void)
1202{
1203}
1204#endif /* CONFIG_BRANCH_TRACER */
1205
1206/* set ring buffers to default size if not already done so */
1207int tracing_update_buffers(void);
1208
1209struct ftrace_event_field {
1210        struct list_head        link;
1211        const char              *name;
1212        const char              *type;
1213        int                     filter_type;
1214        int                     offset;
1215        int                     size;
1216        int                     is_signed;
1217};
1218
1219struct prog_entry;
1220
1221struct event_filter {
1222        struct prog_entry __rcu *prog;
1223        char                    *filter_string;
1224};
1225
1226struct event_subsystem {
1227        struct list_head        list;
1228        const char              *name;
1229        struct event_filter     *filter;
1230        int                     ref_count;
1231};
1232
1233struct trace_subsystem_dir {
1234        struct list_head                list;
1235        struct event_subsystem          *subsystem;
1236        struct trace_array              *tr;
1237        struct dentry                   *entry;
1238        int                             ref_count;
1239        int                             nr_events;
1240};
1241
1242extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
1243                                     struct ring_buffer *buffer,
1244                                     struct ring_buffer_event *event);
1245
1246void trace_buffer_unlock_commit_regs(struct trace_array *tr,
1247                                     struct ring_buffer *buffer,
1248                                     struct ring_buffer_event *event,
1249                                     unsigned long flags, int pc,
1250                                     struct pt_regs *regs);
1251
1252static inline void trace_buffer_unlock_commit(struct trace_array *tr,
1253                                              struct ring_buffer *buffer,
1254                                              struct ring_buffer_event *event,
1255                                              unsigned long flags, int pc)
1256{
1257        trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL);
1258}
1259
1260DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
1261DECLARE_PER_CPU(int, trace_buffered_event_cnt);
1262void trace_buffered_event_disable(void);
1263void trace_buffered_event_enable(void);
1264
1265static inline void
1266__trace_event_discard_commit(struct ring_buffer *buffer,
1267                             struct ring_buffer_event *event)
1268{
1269        if (this_cpu_read(trace_buffered_event) == event) {
1270                /* Simply release the temp buffer */
1271                this_cpu_dec(trace_buffered_event_cnt);
1272                return;
1273        }
1274        ring_buffer_discard_commit(buffer, event);
1275}
1276
1277/*
1278 * Helper function for event_trigger_unlock_commit{_regs}().
1279 * If there are event triggers attached to this event that requires
1280 * filtering against its fields, then they wil be called as the
1281 * entry already holds the field information of the current event.
1282 *
1283 * It also checks if the event should be discarded or not.
1284 * It is to be discarded if the event is soft disabled and the
1285 * event was only recorded to process triggers, or if the event
1286 * filter is active and this event did not match the filters.
1287 *
1288 * Returns true if the event is discarded, false otherwise.
1289 */
1290static inline bool
1291__event_trigger_test_discard(struct trace_event_file *file,
1292                             struct ring_buffer *buffer,
1293                             struct ring_buffer_event *event,
1294                             void *entry,
1295                             enum event_trigger_type *tt)
1296{
1297        unsigned long eflags = file->flags;
1298
1299        if (eflags & EVENT_FILE_FL_TRIGGER_COND)
1300                *tt = event_triggers_call(file, entry, event);
1301
1302        if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
1303            (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
1304             !filter_match_preds(file->filter, entry))) {
1305                __trace_event_discard_commit(buffer, event);
1306                return true;
1307        }
1308
1309        return false;
1310}
1311
1312/**
1313 * event_trigger_unlock_commit - handle triggers and finish event commit
1314 * @file: The file pointer assoctiated to the event
1315 * @buffer: The ring buffer that the event is being written to
1316 * @event: The event meta data in the ring buffer
1317 * @entry: The event itself
1318 * @irq_flags: The state of the interrupts at the start of the event
1319 * @pc: The state of the preempt count at the start of the event.
1320 *
1321 * This is a helper function to handle triggers that require data
1322 * from the event itself. It also tests the event against filters and
1323 * if the event is soft disabled and should be discarded.
1324 */
1325static inline void
1326event_trigger_unlock_commit(struct trace_event_file *file,
1327                            struct ring_buffer *buffer,
1328                            struct ring_buffer_event *event,
1329                            void *entry, unsigned long irq_flags, int pc)
1330{
1331        enum event_trigger_type tt = ETT_NONE;
1332
1333        if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1334                trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
1335
1336        if (tt)
1337                event_triggers_post_call(file, tt, entry, event);
1338}
1339
1340/**
1341 * event_trigger_unlock_commit_regs - handle triggers and finish event commit
1342 * @file: The file pointer assoctiated to the event
1343 * @buffer: The ring buffer that the event is being written to
1344 * @event: The event meta data in the ring buffer
1345 * @entry: The event itself
1346 * @irq_flags: The state of the interrupts at the start of the event
1347 * @pc: The state of the preempt count at the start of the event.
1348 *
1349 * This is a helper function to handle triggers that require data
1350 * from the event itself. It also tests the event against filters and
1351 * if the event is soft disabled and should be discarded.
1352 *
1353 * Same as event_trigger_unlock_commit() but calls
1354 * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
1355 */
1356static inline void
1357event_trigger_unlock_commit_regs(struct trace_event_file *file,
1358                                 struct ring_buffer *buffer,
1359                                 struct ring_buffer_event *event,
1360                                 void *entry, unsigned long irq_flags, int pc,
1361                                 struct pt_regs *regs)
1362{
1363        enum event_trigger_type tt = ETT_NONE;
1364
1365        if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
1366                trace_buffer_unlock_commit_regs(file->tr, buffer, event,
1367                                                irq_flags, pc, regs);
1368
1369        if (tt)
1370                event_triggers_post_call(file, tt, entry, event);
1371}
1372
1373#define FILTER_PRED_INVALID     ((unsigned short)-1)
1374#define FILTER_PRED_IS_RIGHT    (1 << 15)
1375#define FILTER_PRED_FOLD        (1 << 15)
1376
1377/*
1378 * The max preds is the size of unsigned short with
1379 * two flags at the MSBs. One bit is used for both the IS_RIGHT
1380 * and FOLD flags. The other is reserved.
1381 *
1382 * 2^14 preds is way more than enough.
1383 */
1384#define MAX_FILTER_PRED         16384
1385
1386struct filter_pred;
1387struct regex;
1388
1389typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
1390
1391typedef int (*regex_match_func)(char *str, struct regex *r, int len);
1392
1393enum regex_type {
1394        MATCH_FULL = 0,
1395        MATCH_FRONT_ONLY,
1396        MATCH_MIDDLE_ONLY,
1397        MATCH_END_ONLY,
1398        MATCH_GLOB,
1399};
1400
1401struct regex {
1402        char                    pattern[MAX_FILTER_STR_VAL];
1403        int                     len;
1404        int                     field_len;
1405        regex_match_func        match;
1406};
1407
1408struct filter_pred {
1409        filter_pred_fn_t        fn;
1410        u64                     val;
1411        struct regex            regex;
1412        unsigned short          *ops;
1413        struct ftrace_event_field *field;
1414        int                     offset;
1415        int                     not;
1416        int                     op;
1417};
1418
1419static inline bool is_string_field(struct ftrace_event_field *field)
1420{
1421        return field->filter_type == FILTER_DYN_STRING ||
1422               field->filter_type == FILTER_STATIC_STRING ||
1423               field->filter_type == FILTER_PTR_STRING ||
1424               field->filter_type == FILTER_COMM;
1425}
1426
1427static inline bool is_function_field(struct ftrace_event_field *field)
1428{
1429        return field->filter_type == FILTER_TRACE_FN;
1430}
1431
1432extern enum regex_type
1433filter_parse_regex(char *buff, int len, char **search, int *not);
1434extern void print_event_filter(struct trace_event_file *file,
1435                               struct trace_seq *s);
1436extern int apply_event_filter(struct trace_event_file *file,
1437                              char *filter_string);
1438extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
1439                                        char *filter_string);
1440extern void print_subsystem_event_filter(struct event_subsystem *system,
1441                                         struct trace_seq *s);
1442extern int filter_assign_type(const char *type);
1443extern int create_event_filter(struct trace_event_call *call,
1444                               char *filter_str, bool set_str,
1445                               struct event_filter **filterp);
1446extern void free_event_filter(struct event_filter *filter);
1447
1448struct ftrace_event_field *
1449trace_find_event_field(struct trace_event_call *call, char *name);
1450
1451extern void trace_event_enable_cmd_record(bool enable);
1452extern void trace_event_enable_tgid_record(bool enable);
1453
1454extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1455extern int event_trace_del_tracer(struct trace_array *tr);
1456
1457extern struct trace_event_file *find_event_file(struct trace_array *tr,
1458                                                const char *system,
1459                                                const char *event);
1460
1461static inline void *event_file_data(struct file *filp)
1462{
1463        return READ_ONCE(file_inode(filp)->i_private);
1464}
1465
1466extern struct mutex event_mutex;
1467extern struct list_head ftrace_events;
1468
1469extern const struct file_operations event_trigger_fops;
1470extern const struct file_operations event_hist_fops;
1471
1472#ifdef CONFIG_HIST_TRIGGERS
1473extern int register_trigger_hist_cmd(void);
1474extern int register_trigger_hist_enable_disable_cmds(void);
1475#else
1476static inline int register_trigger_hist_cmd(void) { return 0; }
1477static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
1478#endif
1479
1480extern int register_trigger_cmds(void);
1481extern void clear_event_triggers(struct trace_array *tr);
1482
1483struct event_trigger_data {
1484        unsigned long                   count;
1485        int                             ref;
1486        struct event_trigger_ops        *ops;
1487        struct event_command            *cmd_ops;
1488        struct event_filter __rcu       *filter;
1489        char                            *filter_str;
1490        void                            *private_data;
1491        bool                            paused;
1492        bool                            paused_tmp;
1493        struct list_head                list;
1494        char                            *name;
1495        struct list_head                named_list;
1496        struct event_trigger_data       *named_data;
1497};
1498
1499/* Avoid typos */
1500#define ENABLE_EVENT_STR        "enable_event"
1501#define DISABLE_EVENT_STR       "disable_event"
1502#define ENABLE_HIST_STR         "enable_hist"
1503#define DISABLE_HIST_STR        "disable_hist"
1504
1505struct enable_trigger_data {
1506        struct trace_event_file         *file;
1507        bool                            enable;
1508        bool                            hist;
1509};
1510
1511extern int event_enable_trigger_print(struct seq_file *m,
1512                                      struct event_trigger_ops *ops,
1513                                      struct event_trigger_data *data);
1514extern void event_enable_trigger_free(struct event_trigger_ops *ops,
1515                                      struct event_trigger_data *data);
1516extern int event_enable_trigger_func(struct event_command *cmd_ops,
1517                                     struct trace_event_file *file,
1518                                     char *glob, char *cmd, char *param);
1519extern int event_enable_register_trigger(char *glob,
1520                                         struct event_trigger_ops *ops,
1521                                         struct event_trigger_data *data,
1522                                         struct trace_event_file *file);
1523extern void event_enable_unregister_trigger(char *glob,
1524                                            struct event_trigger_ops *ops,
1525                                            struct event_trigger_data *test,
1526                                            struct trace_event_file *file);
1527extern void trigger_data_free(struct event_trigger_data *data);
1528extern int event_trigger_init(struct event_trigger_ops *ops,
1529                              struct event_trigger_data *data);
1530extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
1531                                              int trigger_enable);
1532extern void update_cond_flag(struct trace_event_file *file);
1533extern void unregister_trigger(char *glob, struct event_trigger_ops *ops,
1534                               struct event_trigger_data *test,
1535                               struct trace_event_file *file);
1536extern int set_trigger_filter(char *filter_str,
1537                              struct event_trigger_data *trigger_data,
1538                              struct trace_event_file *file);
1539extern struct event_trigger_data *find_named_trigger(const char *name);
1540extern bool is_named_trigger(struct event_trigger_data *test);
1541extern int save_named_trigger(const char *name,
1542                              struct event_trigger_data *data);
1543extern void del_named_trigger(struct event_trigger_data *data);
1544extern void pause_named_trigger(struct event_trigger_data *data);
1545extern void unpause_named_trigger(struct event_trigger_data *data);
1546extern void set_named_trigger_data(struct event_trigger_data *data,
1547                                   struct event_trigger_data *named_data);
1548extern struct event_trigger_data *
1549get_named_trigger_data(struct event_trigger_data *data);
1550extern int register_event_command(struct event_command *cmd);
1551extern int unregister_event_command(struct event_command *cmd);
1552extern int register_trigger_hist_enable_disable_cmds(void);
1553
1554/**
1555 * struct event_trigger_ops - callbacks for trace event triggers
1556 *
1557 * The methods in this structure provide per-event trigger hooks for
1558 * various trigger operations.
1559 *
1560 * All the methods below, except for @init() and @free(), must be
1561 * implemented.
1562 *
1563 * @func: The trigger 'probe' function called when the triggering
1564 *      event occurs.  The data passed into this callback is the data
1565 *      that was supplied to the event_command @reg() function that
1566 *      registered the trigger (see struct event_command) along with
1567 *      the trace record, rec.
1568 *
1569 * @init: An optional initialization function called for the trigger
1570 *      when the trigger is registered (via the event_command reg()
1571 *      function).  This can be used to perform per-trigger
1572 *      initialization such as incrementing a per-trigger reference
1573 *      count, for instance.  This is usually implemented by the
1574 *      generic utility function @event_trigger_init() (see
1575 *      trace_event_triggers.c).
1576 *
1577 * @free: An optional de-initialization function called for the
1578 *      trigger when the trigger is unregistered (via the
1579 *      event_command @reg() function).  This can be used to perform
1580 *      per-trigger de-initialization such as decrementing a
1581 *      per-trigger reference count and freeing corresponding trigger
1582 *      data, for instance.  This is usually implemented by the
1583 *      generic utility function @event_trigger_free() (see
1584 *      trace_event_triggers.c).
1585 *
1586 * @print: The callback function invoked to have the trigger print
1587 *      itself.  This is usually implemented by a wrapper function
1588 *      that calls the generic utility function @event_trigger_print()
1589 *      (see trace_event_triggers.c).
1590 */
1591struct event_trigger_ops {
1592        void                    (*func)(struct event_trigger_data *data,
1593                                        void *rec,
1594                                        struct ring_buffer_event *rbe);
1595        int                     (*init)(struct event_trigger_ops *ops,
1596                                        struct event_trigger_data *data);
1597        void                    (*free)(struct event_trigger_ops *ops,
1598                                        struct event_trigger_data *data);
1599        int                     (*print)(struct seq_file *m,
1600                                         struct event_trigger_ops *ops,
1601                                         struct event_trigger_data *data);
1602};
1603
1604/**
1605 * struct event_command - callbacks and data members for event commands
1606 *
1607 * Event commands are invoked by users by writing the command name
1608 * into the 'trigger' file associated with a trace event.  The
1609 * parameters associated with a specific invocation of an event
1610 * command are used to create an event trigger instance, which is
1611 * added to the list of trigger instances associated with that trace
1612 * event.  When the event is hit, the set of triggers associated with
1613 * that event is invoked.
1614 *
1615 * The data members in this structure provide per-event command data
1616 * for various event commands.
1617 *
1618 * All the data members below, except for @post_trigger, must be set
1619 * for each event command.
1620 *
1621 * @name: The unique name that identifies the event command.  This is
1622 *      the name used when setting triggers via trigger files.
1623 *
1624 * @trigger_type: A unique id that identifies the event command
1625 *      'type'.  This value has two purposes, the first to ensure that
1626 *      only one trigger of the same type can be set at a given time
1627 *      for a particular event e.g. it doesn't make sense to have both
1628 *      a traceon and traceoff trigger attached to a single event at
1629 *      the same time, so traceon and traceoff have the same type
1630 *      though they have different names.  The @trigger_type value is
1631 *      also used as a bit value for deferring the actual trigger
1632 *      action until after the current event is finished.  Some
1633 *      commands need to do this if they themselves log to the trace
1634 *      buffer (see the @post_trigger() member below).  @trigger_type
1635 *      values are defined by adding new values to the trigger_type
1636 *      enum in include/linux/trace_events.h.
1637 *
1638 * @flags: See the enum event_command_flags below.
1639 *
1640 * All the methods below, except for @set_filter() and @unreg_all(),
1641 * must be implemented.
1642 *
1643 * @func: The callback function responsible for parsing and
1644 *      registering the trigger written to the 'trigger' file by the
1645 *      user.  It allocates the trigger instance and registers it with
1646 *      the appropriate trace event.  It makes use of the other
1647 *      event_command callback functions to orchestrate this, and is
1648 *      usually implemented by the generic utility function
1649 *      @event_trigger_callback() (see trace_event_triggers.c).
1650 *
1651 * @reg: Adds the trigger to the list of triggers associated with the
1652 *      event, and enables the event trigger itself, after
1653 *      initializing it (via the event_trigger_ops @init() function).
1654 *      This is also where commands can use the @trigger_type value to
1655 *      make the decision as to whether or not multiple instances of
1656 *      the trigger should be allowed.  This is usually implemented by
1657 *      the generic utility function @register_trigger() (see
1658 *      trace_event_triggers.c).
1659 *
1660 * @unreg: Removes the trigger from the list of triggers associated
1661 *      with the event, and disables the event trigger itself, after
1662 *      initializing it (via the event_trigger_ops @free() function).
1663 *      This is usually implemented by the generic utility function
1664 *      @unregister_trigger() (see trace_event_triggers.c).
1665 *
1666 * @unreg_all: An optional function called to remove all the triggers
1667 *      from the list of triggers associated with the event.  Called
1668 *      when a trigger file is opened in truncate mode.
1669 *
1670 * @set_filter: An optional function called to parse and set a filter
1671 *      for the trigger.  If no @set_filter() method is set for the
1672 *      event command, filters set by the user for the command will be
1673 *      ignored.  This is usually implemented by the generic utility
1674 *      function @set_trigger_filter() (see trace_event_triggers.c).
1675 *
1676 * @get_trigger_ops: The callback function invoked to retrieve the
1677 *      event_trigger_ops implementation associated with the command.
1678 */
1679struct event_command {
1680        struct list_head        list;
1681        char                    *name;
1682        enum event_trigger_type trigger_type;
1683        int                     flags;
1684        int                     (*func)(struct event_command *cmd_ops,
1685                                        struct trace_event_file *file,
1686                                        char *glob, char *cmd, char *params);
1687        int                     (*reg)(char *glob,
1688                                       struct event_trigger_ops *ops,
1689                                       struct event_trigger_data *data,
1690                                       struct trace_event_file *file);
1691        void                    (*unreg)(char *glob,
1692                                         struct event_trigger_ops *ops,
1693                                         struct event_trigger_data *data,
1694                                         struct trace_event_file *file);
1695        void                    (*unreg_all)(struct trace_event_file *file);
1696        int                     (*set_filter)(char *filter_str,
1697                                              struct event_trigger_data *data,
1698                                              struct trace_event_file *file);
1699        struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
1700};
1701
1702/**
1703 * enum event_command_flags - flags for struct event_command
1704 *
1705 * @POST_TRIGGER: A flag that says whether or not this command needs
1706 *      to have its action delayed until after the current event has
1707 *      been closed.  Some triggers need to avoid being invoked while
1708 *      an event is currently in the process of being logged, since
1709 *      the trigger may itself log data into the trace buffer.  Thus
1710 *      we make sure the current event is committed before invoking
1711 *      those triggers.  To do that, the trigger invocation is split
1712 *      in two - the first part checks the filter using the current
1713 *      trace record; if a command has the @post_trigger flag set, it
1714 *      sets a bit for itself in the return value, otherwise it
1715 *      directly invokes the trigger.  Once all commands have been
1716 *      either invoked or set their return flag, the current record is
1717 *      either committed or discarded.  At that point, if any commands
1718 *      have deferred their triggers, those commands are finally
1719 *      invoked following the close of the current event.  In other
1720 *      words, if the event_trigger_ops @func() probe implementation
1721 *      itself logs to the trace buffer, this flag should be set,
1722 *      otherwise it can be left unspecified.
1723 *
1724 * @NEEDS_REC: A flag that says whether or not this command needs
1725 *      access to the trace record in order to perform its function,
1726 *      regardless of whether or not it has a filter associated with
1727 *      it (filters make a trigger require access to the trace record
1728 *      but are not always present).
1729 */
1730enum event_command_flags {
1731        EVENT_CMD_FL_POST_TRIGGER       = 1,
1732        EVENT_CMD_FL_NEEDS_REC          = 2,
1733};
1734
1735static inline bool event_command_post_trigger(struct event_command *cmd_ops)
1736{
1737        return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
1738}
1739
1740static inline bool event_command_needs_rec(struct event_command *cmd_ops)
1741{
1742        return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
1743}
1744
1745extern int trace_event_enable_disable(struct trace_event_file *file,
1746                                      int enable, int soft_disable);
1747extern int tracing_alloc_snapshot(void);
1748
1749extern const char *__start___trace_bprintk_fmt[];
1750extern const char *__stop___trace_bprintk_fmt[];
1751
1752extern const char *__start___tracepoint_str[];
1753extern const char *__stop___tracepoint_str[];
1754
1755void trace_printk_control(bool enabled);
1756void trace_printk_init_buffers(void);
1757void trace_printk_start_comm(void);
1758int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1759int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1760
1761#define MAX_EVENT_NAME_LEN      64
1762
1763extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
1764extern ssize_t trace_parse_run_command(struct file *file,
1765                const char __user *buffer, size_t count, loff_t *ppos,
1766                int (*createfn)(int, char**));
1767
1768/*
1769 * Normal trace_printk() and friends allocates special buffers
1770 * to do the manipulation, as well as saves the print formats
1771 * into sections to display. But the trace infrastructure wants
1772 * to use these without the added overhead at the price of being
1773 * a bit slower (used mainly for warnings, where we don't care
1774 * about performance). The internal_trace_puts() is for such
1775 * a purpose.
1776 */
1777#define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1778
1779#undef FTRACE_ENTRY
1780#define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)     \
1781        extern struct trace_event_call                                  \
1782        __aligned(4) event_##call;
1783#undef FTRACE_ENTRY_DUP
1784#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter) \
1785        FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1786                     filter)
1787#undef FTRACE_ENTRY_PACKED
1788#define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print, filter) \
1789        FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1790                     filter)
1791
1792#include "trace_entries.h"
1793
1794#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1795int perf_ftrace_event_register(struct trace_event_call *call,
1796                               enum trace_reg type, void *data);
1797#else
1798#define perf_ftrace_event_register NULL
1799#endif
1800
1801#ifdef CONFIG_FTRACE_SYSCALLS
1802void init_ftrace_syscalls(void);
1803const char *get_syscall_name(int syscall);
1804#else
1805static inline void init_ftrace_syscalls(void) { }
1806static inline const char *get_syscall_name(int syscall)
1807{
1808        return NULL;
1809}
1810#endif
1811
1812#ifdef CONFIG_EVENT_TRACING
1813void trace_event_init(void);
1814void trace_event_eval_update(struct trace_eval_map **map, int len);
1815#else
1816static inline void __init trace_event_init(void) { }
1817static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
1818#endif
1819
1820#ifdef CONFIG_TRACER_SNAPSHOT
1821void tracing_snapshot_instance(struct trace_array *tr);
1822int tracing_alloc_snapshot_instance(struct trace_array *tr);
1823#else
1824static inline void tracing_snapshot_instance(struct trace_array *tr) { }
1825static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
1826{
1827        return 0;
1828}
1829#endif
1830
1831extern struct trace_iterator *tracepoint_print_iter;
1832
1833#endif /* _LINUX_KERNEL_TRACE_H */
1834