linux/kernel/trace/trace.h
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   1#ifndef _LINUX_KERNEL_TRACE_H
   2#define _LINUX_KERNEL_TRACE_H
   3
   4#include <linux/fs.h>
   5#include <linux/atomic.h>
   6#include <linux/sched.h>
   7#include <linux/clocksource.h>
   8#include <linux/ring_buffer.h>
   9#include <linux/mmiotrace.h>
  10#include <linux/tracepoint.h>
  11#include <linux/ftrace.h>
  12#include <linux/hw_breakpoint.h>
  13#include <linux/trace_seq.h>
  14#include <linux/ftrace_event.h>
  15
  16#ifdef CONFIG_FTRACE_SYSCALLS
  17#include <asm/unistd.h>         /* For NR_SYSCALLS           */
  18#include <asm/syscall.h>        /* some archs define it here */
  19#endif
  20
  21enum trace_type {
  22        __TRACE_FIRST_TYPE = 0,
  23
  24        TRACE_FN,
  25        TRACE_CTX,
  26        TRACE_WAKE,
  27        TRACE_STACK,
  28        TRACE_PRINT,
  29        TRACE_BPRINT,
  30        TRACE_MMIO_RW,
  31        TRACE_MMIO_MAP,
  32        TRACE_BRANCH,
  33        TRACE_GRAPH_RET,
  34        TRACE_GRAPH_ENT,
  35        TRACE_USER_STACK,
  36        TRACE_BLK,
  37        TRACE_BPUTS,
  38
  39        __TRACE_LAST_TYPE,
  40};
  41
  42
  43#undef __field
  44#define __field(type, item)             type    item;
  45
  46#undef __field_struct
  47#define __field_struct(type, item)      __field(type, item)
  48
  49#undef __field_desc
  50#define __field_desc(type, container, item)
  51
  52#undef __array
  53#define __array(type, item, size)       type    item[size];
  54
  55#undef __array_desc
  56#define __array_desc(type, container, item, size)
  57
  58#undef __dynamic_array
  59#define __dynamic_array(type, item)     type    item[];
  60
  61#undef F_STRUCT
  62#define F_STRUCT(args...)               args
  63
  64#undef FTRACE_ENTRY
  65#define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)     \
  66        struct struct_name {                                            \
  67                struct trace_entry      ent;                            \
  68                tstruct                                                 \
  69        }
  70
  71#undef TP_ARGS
  72#define TP_ARGS(args...)        args
  73
  74#undef FTRACE_ENTRY_DUP
  75#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
  76
  77#undef FTRACE_ENTRY_REG
  78#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
  79                         filter, regfn) \
  80        FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
  81                     filter)
  82
  83#include "trace_entries.h"
  84
  85/*
  86 * syscalls are special, and need special handling, this is why
  87 * they are not included in trace_entries.h
  88 */
  89struct syscall_trace_enter {
  90        struct trace_entry      ent;
  91        int                     nr;
  92        unsigned long           args[];
  93};
  94
  95struct syscall_trace_exit {
  96        struct trace_entry      ent;
  97        int                     nr;
  98        long                    ret;
  99};
 100
 101struct kprobe_trace_entry_head {
 102        struct trace_entry      ent;
 103        unsigned long           ip;
 104};
 105
 106struct kretprobe_trace_entry_head {
 107        struct trace_entry      ent;
 108        unsigned long           func;
 109        unsigned long           ret_ip;
 110};
 111
 112/*
 113 * trace_flag_type is an enumeration that holds different
 114 * states when a trace occurs. These are:
 115 *  IRQS_OFF            - interrupts were disabled
 116 *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 117 *  NEED_RESCHED        - reschedule is requested
 118 *  HARDIRQ             - inside an interrupt handler
 119 *  SOFTIRQ             - inside a softirq handler
 120 */
 121enum trace_flag_type {
 122        TRACE_FLAG_IRQS_OFF             = 0x01,
 123        TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 124        TRACE_FLAG_NEED_RESCHED         = 0x04,
 125        TRACE_FLAG_HARDIRQ              = 0x08,
 126        TRACE_FLAG_SOFTIRQ              = 0x10,
 127};
 128
 129#define TRACE_BUF_SIZE          1024
 130
 131struct trace_array;
 132
 133struct trace_cpu {
 134        struct trace_array      *tr;
 135        struct dentry           *dir;
 136        int                     cpu;
 137};
 138
 139/*
 140 * The CPU trace array - it consists of thousands of trace entries
 141 * plus some other descriptor data: (for example which task started
 142 * the trace, etc.)
 143 */
 144struct trace_array_cpu {
 145        struct trace_cpu        trace_cpu;
 146        atomic_t                disabled;
 147        void                    *buffer_page;   /* ring buffer spare */
 148
 149        unsigned long           entries;
 150        unsigned long           saved_latency;
 151        unsigned long           critical_start;
 152        unsigned long           critical_end;
 153        unsigned long           critical_sequence;
 154        unsigned long           nice;
 155        unsigned long           policy;
 156        unsigned long           rt_priority;
 157        unsigned long           skipped_entries;
 158        cycle_t                 preempt_timestamp;
 159        pid_t                   pid;
 160        kuid_t                  uid;
 161        char                    comm[TASK_COMM_LEN];
 162};
 163
 164struct tracer;
 165
 166struct trace_buffer {
 167        struct trace_array              *tr;
 168        struct ring_buffer              *buffer;
 169        struct trace_array_cpu __percpu *data;
 170        cycle_t                         time_start;
 171        int                             cpu;
 172};
 173
 174/*
 175 * The trace array - an array of per-CPU trace arrays. This is the
 176 * highest level data structure that individual tracers deal with.
 177 * They have on/off state as well:
 178 */
 179struct trace_array {
 180        struct list_head        list;
 181        char                    *name;
 182        struct trace_buffer     trace_buffer;
 183#ifdef CONFIG_TRACER_MAX_TRACE
 184        /*
 185         * The max_buffer is used to snapshot the trace when a maximum
 186         * latency is reached, or when the user initiates a snapshot.
 187         * Some tracers will use this to store a maximum trace while
 188         * it continues examining live traces.
 189         *
 190         * The buffers for the max_buffer are set up the same as the trace_buffer
 191         * When a snapshot is taken, the buffer of the max_buffer is swapped
 192         * with the buffer of the trace_buffer and the buffers are reset for
 193         * the trace_buffer so the tracing can continue.
 194         */
 195        struct trace_buffer     max_buffer;
 196        bool                    allocated_snapshot;
 197#endif
 198        int                     buffer_disabled;
 199        struct trace_cpu        trace_cpu;      /* place holder */
 200#ifdef CONFIG_FTRACE_SYSCALLS
 201        int                     sys_refcount_enter;
 202        int                     sys_refcount_exit;
 203        DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
 204        DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
 205#endif
 206        int                     stop_count;
 207        int                     clock_id;
 208        struct tracer           *current_trace;
 209        unsigned int            flags;
 210        raw_spinlock_t          start_lock;
 211        struct dentry           *dir;
 212        struct dentry           *options;
 213        struct dentry           *percpu_dir;
 214        struct dentry           *event_dir;
 215        struct list_head        systems;
 216        struct list_head        events;
 217        struct task_struct      *waiter;
 218        int                     ref;
 219};
 220
 221enum {
 222        TRACE_ARRAY_FL_GLOBAL   = (1 << 0)
 223};
 224
 225extern struct list_head ftrace_trace_arrays;
 226
 227/*
 228 * The global tracer (top) should be the first trace array added,
 229 * but we check the flag anyway.
 230 */
 231static inline struct trace_array *top_trace_array(void)
 232{
 233        struct trace_array *tr;
 234
 235        tr = list_entry(ftrace_trace_arrays.prev,
 236                        typeof(*tr), list);
 237        WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
 238        return tr;
 239}
 240
 241#define FTRACE_CMP_TYPE(var, type) \
 242        __builtin_types_compatible_p(typeof(var), type *)
 243
 244#undef IF_ASSIGN
 245#define IF_ASSIGN(var, entry, etype, id)                \
 246        if (FTRACE_CMP_TYPE(var, etype)) {              \
 247                var = (typeof(var))(entry);             \
 248                WARN_ON(id && (entry)->type != id);     \
 249                break;                                  \
 250        }
 251
 252/* Will cause compile errors if type is not found. */
 253extern void __ftrace_bad_type(void);
 254
 255/*
 256 * The trace_assign_type is a verifier that the entry type is
 257 * the same as the type being assigned. To add new types simply
 258 * add a line with the following format:
 259 *
 260 * IF_ASSIGN(var, ent, type, id);
 261 *
 262 *  Where "type" is the trace type that includes the trace_entry
 263 *  as the "ent" item. And "id" is the trace identifier that is
 264 *  used in the trace_type enum.
 265 *
 266 *  If the type can have more than one id, then use zero.
 267 */
 268#define trace_assign_type(var, ent)                                     \
 269        do {                                                            \
 270                IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 271                IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 272                IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 273                IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 274                IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 275                IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 276                IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);   \
 277                IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 278                          TRACE_MMIO_RW);                               \
 279                IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 280                          TRACE_MMIO_MAP);                              \
 281                IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 282                IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 283                          TRACE_GRAPH_ENT);             \
 284                IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 285                          TRACE_GRAPH_RET);             \
 286                __ftrace_bad_type();                                    \
 287        } while (0)
 288
 289/*
 290 * An option specific to a tracer. This is a boolean value.
 291 * The bit is the bit index that sets its value on the
 292 * flags value in struct tracer_flags.
 293 */
 294struct tracer_opt {
 295        const char      *name; /* Will appear on the trace_options file */
 296        u32             bit; /* Mask assigned in val field in tracer_flags */
 297};
 298
 299/*
 300 * The set of specific options for a tracer. Your tracer
 301 * have to set the initial value of the flags val.
 302 */
 303struct tracer_flags {
 304        u32                     val;
 305        struct tracer_opt       *opts;
 306};
 307
 308/* Makes more easy to define a tracer opt */
 309#define TRACER_OPT(s, b)        .name = #s, .bit = b
 310
 311
 312/**
 313 * struct tracer - a specific tracer and its callbacks to interact with debugfs
 314 * @name: the name chosen to select it on the available_tracers file
 315 * @init: called when one switches to this tracer (echo name > current_tracer)
 316 * @reset: called when one switches to another tracer
 317 * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 318 * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 319 * @open: called when the trace file is opened
 320 * @pipe_open: called when the trace_pipe file is opened
 321 * @wait_pipe: override how the user waits for traces on trace_pipe
 322 * @close: called when the trace file is released
 323 * @pipe_close: called when the trace_pipe file is released
 324 * @read: override the default read callback on trace_pipe
 325 * @splice_read: override the default splice_read callback on trace_pipe
 326 * @selftest: selftest to run on boot (see trace_selftest.c)
 327 * @print_headers: override the first lines that describe your columns
 328 * @print_line: callback that prints a trace
 329 * @set_flag: signals one of your private flags changed (trace_options file)
 330 * @flags: your private flags
 331 */
 332struct tracer {
 333        const char              *name;
 334        int                     (*init)(struct trace_array *tr);
 335        void                    (*reset)(struct trace_array *tr);
 336        void                    (*start)(struct trace_array *tr);
 337        void                    (*stop)(struct trace_array *tr);
 338        void                    (*open)(struct trace_iterator *iter);
 339        void                    (*pipe_open)(struct trace_iterator *iter);
 340        void                    (*wait_pipe)(struct trace_iterator *iter);
 341        void                    (*close)(struct trace_iterator *iter);
 342        void                    (*pipe_close)(struct trace_iterator *iter);
 343        ssize_t                 (*read)(struct trace_iterator *iter,
 344                                        struct file *filp, char __user *ubuf,
 345                                        size_t cnt, loff_t *ppos);
 346        ssize_t                 (*splice_read)(struct trace_iterator *iter,
 347                                               struct file *filp,
 348                                               loff_t *ppos,
 349                                               struct pipe_inode_info *pipe,
 350                                               size_t len,
 351                                               unsigned int flags);
 352#ifdef CONFIG_FTRACE_STARTUP_TEST
 353        int                     (*selftest)(struct tracer *trace,
 354                                            struct trace_array *tr);
 355#endif
 356        void                    (*print_header)(struct seq_file *m);
 357        enum print_line_t       (*print_line)(struct trace_iterator *iter);
 358        /* If you handled the flag setting, return 0 */
 359        int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 360        /* Return 0 if OK with change, else return non-zero */
 361        int                     (*flag_changed)(struct tracer *tracer,
 362                                                u32 mask, int set);
 363        struct tracer           *next;
 364        struct tracer_flags     *flags;
 365        bool                    print_max;
 366        bool                    enabled;
 367#ifdef CONFIG_TRACER_MAX_TRACE
 368        bool                    use_max_tr;
 369#endif
 370};
 371
 372
 373/* Only current can touch trace_recursion */
 374
 375/*
 376 * For function tracing recursion:
 377 *  The order of these bits are important.
 378 *
 379 *  When function tracing occurs, the following steps are made:
 380 *   If arch does not support a ftrace feature:
 381 *    call internal function (uses INTERNAL bits) which calls...
 382 *   If callback is registered to the "global" list, the list
 383 *    function is called and recursion checks the GLOBAL bits.
 384 *    then this function calls...
 385 *   The function callback, which can use the FTRACE bits to
 386 *    check for recursion.
 387 *
 388 * Now if the arch does not suppport a feature, and it calls
 389 * the global list function which calls the ftrace callback
 390 * all three of these steps will do a recursion protection.
 391 * There's no reason to do one if the previous caller already
 392 * did. The recursion that we are protecting against will
 393 * go through the same steps again.
 394 *
 395 * To prevent the multiple recursion checks, if a recursion
 396 * bit is set that is higher than the MAX bit of the current
 397 * check, then we know that the check was made by the previous
 398 * caller, and we can skip the current check.
 399 */
 400enum {
 401        TRACE_BUFFER_BIT,
 402        TRACE_BUFFER_NMI_BIT,
 403        TRACE_BUFFER_IRQ_BIT,
 404        TRACE_BUFFER_SIRQ_BIT,
 405
 406        /* Start of function recursion bits */
 407        TRACE_FTRACE_BIT,
 408        TRACE_FTRACE_NMI_BIT,
 409        TRACE_FTRACE_IRQ_BIT,
 410        TRACE_FTRACE_SIRQ_BIT,
 411
 412        /* GLOBAL_BITs must be greater than FTRACE_BITs */
 413        TRACE_GLOBAL_BIT,
 414        TRACE_GLOBAL_NMI_BIT,
 415        TRACE_GLOBAL_IRQ_BIT,
 416        TRACE_GLOBAL_SIRQ_BIT,
 417
 418        /* INTERNAL_BITs must be greater than GLOBAL_BITs */
 419        TRACE_INTERNAL_BIT,
 420        TRACE_INTERNAL_NMI_BIT,
 421        TRACE_INTERNAL_IRQ_BIT,
 422        TRACE_INTERNAL_SIRQ_BIT,
 423
 424        TRACE_CONTROL_BIT,
 425
 426/*
 427 * Abuse of the trace_recursion.
 428 * As we need a way to maintain state if we are tracing the function
 429 * graph in irq because we want to trace a particular function that
 430 * was called in irq context but we have irq tracing off. Since this
 431 * can only be modified by current, we can reuse trace_recursion.
 432 */
 433        TRACE_IRQ_BIT,
 434};
 435
 436#define trace_recursion_set(bit)        do { (current)->trace_recursion |= (1<<(bit)); } while (0)
 437#define trace_recursion_clear(bit)      do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
 438#define trace_recursion_test(bit)       ((current)->trace_recursion & (1<<(bit)))
 439
 440#define TRACE_CONTEXT_BITS      4
 441
 442#define TRACE_FTRACE_START      TRACE_FTRACE_BIT
 443#define TRACE_FTRACE_MAX        ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
 444
 445#define TRACE_GLOBAL_START      TRACE_GLOBAL_BIT
 446#define TRACE_GLOBAL_MAX        ((1 << (TRACE_GLOBAL_START + TRACE_CONTEXT_BITS)) - 1)
 447
 448#define TRACE_LIST_START        TRACE_INTERNAL_BIT
 449#define TRACE_LIST_MAX          ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
 450
 451#define TRACE_CONTEXT_MASK      TRACE_LIST_MAX
 452
 453static __always_inline int trace_get_context_bit(void)
 454{
 455        int bit;
 456
 457        if (in_interrupt()) {
 458                if (in_nmi())
 459                        bit = 0;
 460
 461                else if (in_irq())
 462                        bit = 1;
 463                else
 464                        bit = 2;
 465        } else
 466                bit = 3;
 467
 468        return bit;
 469}
 470
 471static __always_inline int trace_test_and_set_recursion(int start, int max)
 472{
 473        unsigned int val = current->trace_recursion;
 474        int bit;
 475
 476        /* A previous recursion check was made */
 477        if ((val & TRACE_CONTEXT_MASK) > max)
 478                return 0;
 479
 480        bit = trace_get_context_bit() + start;
 481        if (unlikely(val & (1 << bit)))
 482                return -1;
 483
 484        val |= 1 << bit;
 485        current->trace_recursion = val;
 486        barrier();
 487
 488        return bit;
 489}
 490
 491static __always_inline void trace_clear_recursion(int bit)
 492{
 493        unsigned int val = current->trace_recursion;
 494
 495        if (!bit)
 496                return;
 497
 498        bit = 1 << bit;
 499        val &= ~bit;
 500
 501        barrier();
 502        current->trace_recursion = val;
 503}
 504
 505static inline struct ring_buffer_iter *
 506trace_buffer_iter(struct trace_iterator *iter, int cpu)
 507{
 508        if (iter->buffer_iter && iter->buffer_iter[cpu])
 509                return iter->buffer_iter[cpu];
 510        return NULL;
 511}
 512
 513int tracer_init(struct tracer *t, struct trace_array *tr);
 514int tracing_is_enabled(void);
 515void tracing_reset(struct trace_buffer *buf, int cpu);
 516void tracing_reset_online_cpus(struct trace_buffer *buf);
 517void tracing_reset_current(int cpu);
 518void tracing_reset_all_online_cpus(void);
 519int tracing_open_generic(struct inode *inode, struct file *filp);
 520struct dentry *trace_create_file(const char *name,
 521                                 umode_t mode,
 522                                 struct dentry *parent,
 523                                 void *data,
 524                                 const struct file_operations *fops);
 525
 526struct dentry *tracing_init_dentry_tr(struct trace_array *tr);
 527struct dentry *tracing_init_dentry(void);
 528
 529struct ring_buffer_event;
 530
 531struct ring_buffer_event *
 532trace_buffer_lock_reserve(struct ring_buffer *buffer,
 533                          int type,
 534                          unsigned long len,
 535                          unsigned long flags,
 536                          int pc);
 537
 538struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 539                                                struct trace_array_cpu *data);
 540
 541struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 542                                          int *ent_cpu, u64 *ent_ts);
 543
 544void __buffer_unlock_commit(struct ring_buffer *buffer,
 545                            struct ring_buffer_event *event);
 546
 547int trace_empty(struct trace_iterator *iter);
 548
 549void *trace_find_next_entry_inc(struct trace_iterator *iter);
 550
 551void trace_init_global_iter(struct trace_iterator *iter);
 552
 553void tracing_iter_reset(struct trace_iterator *iter, int cpu);
 554
 555void poll_wait_pipe(struct trace_iterator *iter);
 556
 557void ftrace(struct trace_array *tr,
 558                            struct trace_array_cpu *data,
 559                            unsigned long ip,
 560                            unsigned long parent_ip,
 561                            unsigned long flags, int pc);
 562void tracing_sched_switch_trace(struct trace_array *tr,
 563                                struct task_struct *prev,
 564                                struct task_struct *next,
 565                                unsigned long flags, int pc);
 566
 567void tracing_sched_wakeup_trace(struct trace_array *tr,
 568                                struct task_struct *wakee,
 569                                struct task_struct *cur,
 570                                unsigned long flags, int pc);
 571void trace_function(struct trace_array *tr,
 572                    unsigned long ip,
 573                    unsigned long parent_ip,
 574                    unsigned long flags, int pc);
 575void trace_graph_function(struct trace_array *tr,
 576                    unsigned long ip,
 577                    unsigned long parent_ip,
 578                    unsigned long flags, int pc);
 579void trace_latency_header(struct seq_file *m);
 580void trace_default_header(struct seq_file *m);
 581void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
 582int trace_empty(struct trace_iterator *iter);
 583
 584void trace_graph_return(struct ftrace_graph_ret *trace);
 585int trace_graph_entry(struct ftrace_graph_ent *trace);
 586void set_graph_array(struct trace_array *tr);
 587
 588void tracing_start_cmdline_record(void);
 589void tracing_stop_cmdline_record(void);
 590void tracing_sched_switch_assign_trace(struct trace_array *tr);
 591void tracing_stop_sched_switch_record(void);
 592void tracing_start_sched_switch_record(void);
 593int register_tracer(struct tracer *type);
 594int is_tracing_stopped(void);
 595
 596extern cpumask_var_t __read_mostly tracing_buffer_mask;
 597
 598#define for_each_tracing_cpu(cpu)       \
 599        for_each_cpu(cpu, tracing_buffer_mask)
 600
 601extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 602
 603extern unsigned long tracing_thresh;
 604
 605#ifdef CONFIG_TRACER_MAX_TRACE
 606extern unsigned long tracing_max_latency;
 607
 608void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 609void update_max_tr_single(struct trace_array *tr,
 610                          struct task_struct *tsk, int cpu);
 611#endif /* CONFIG_TRACER_MAX_TRACE */
 612
 613#ifdef CONFIG_STACKTRACE
 614void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 615                        int skip, int pc);
 616
 617void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
 618                             int skip, int pc, struct pt_regs *regs);
 619
 620void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 621                            int pc);
 622
 623void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 624                   int pc);
 625#else
 626static inline void ftrace_trace_stack(struct ring_buffer *buffer,
 627                                      unsigned long flags, int skip, int pc)
 628{
 629}
 630
 631static inline void ftrace_trace_stack_regs(struct ring_buffer *buffer,
 632                                           unsigned long flags, int skip,
 633                                           int pc, struct pt_regs *regs)
 634{
 635}
 636
 637static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
 638                                          unsigned long flags, int pc)
 639{
 640}
 641
 642static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 643                                 int skip, int pc)
 644{
 645}
 646#endif /* CONFIG_STACKTRACE */
 647
 648extern cycle_t ftrace_now(int cpu);
 649
 650extern void trace_find_cmdline(int pid, char comm[]);
 651
 652#ifdef CONFIG_DYNAMIC_FTRACE
 653extern unsigned long ftrace_update_tot_cnt;
 654#endif
 655#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 656extern int DYN_FTRACE_TEST_NAME(void);
 657#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
 658extern int DYN_FTRACE_TEST_NAME2(void);
 659
 660extern bool ring_buffer_expanded;
 661extern bool tracing_selftest_disabled;
 662DECLARE_PER_CPU(int, ftrace_cpu_disabled);
 663
 664#ifdef CONFIG_FTRACE_STARTUP_TEST
 665extern int trace_selftest_startup_function(struct tracer *trace,
 666                                           struct trace_array *tr);
 667extern int trace_selftest_startup_function_graph(struct tracer *trace,
 668                                                 struct trace_array *tr);
 669extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 670                                          struct trace_array *tr);
 671extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 672                                             struct trace_array *tr);
 673extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 674                                                 struct trace_array *tr);
 675extern int trace_selftest_startup_wakeup(struct tracer *trace,
 676                                         struct trace_array *tr);
 677extern int trace_selftest_startup_nop(struct tracer *trace,
 678                                         struct trace_array *tr);
 679extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 680                                               struct trace_array *tr);
 681extern int trace_selftest_startup_branch(struct tracer *trace,
 682                                         struct trace_array *tr);
 683#endif /* CONFIG_FTRACE_STARTUP_TEST */
 684
 685extern void *head_page(struct trace_array_cpu *data);
 686extern unsigned long long ns2usecs(cycle_t nsec);
 687extern int
 688trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 689extern int
 690trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 691extern int
 692trace_array_vprintk(struct trace_array *tr,
 693                    unsigned long ip, const char *fmt, va_list args);
 694int trace_array_printk(struct trace_array *tr,
 695                       unsigned long ip, const char *fmt, ...);
 696int trace_array_printk_buf(struct ring_buffer *buffer,
 697                           unsigned long ip, const char *fmt, ...);
 698void trace_printk_seq(struct trace_seq *s);
 699enum print_line_t print_trace_line(struct trace_iterator *iter);
 700
 701extern unsigned long trace_flags;
 702
 703/* Standard output formatting function used for function return traces */
 704#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 705
 706/* Flag options */
 707#define TRACE_GRAPH_PRINT_OVERRUN       0x1
 708#define TRACE_GRAPH_PRINT_CPU           0x2
 709#define TRACE_GRAPH_PRINT_OVERHEAD      0x4
 710#define TRACE_GRAPH_PRINT_PROC          0x8
 711#define TRACE_GRAPH_PRINT_DURATION      0x10
 712#define TRACE_GRAPH_PRINT_ABS_TIME      0x20
 713
 714extern enum print_line_t
 715print_graph_function_flags(struct trace_iterator *iter, u32 flags);
 716extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
 717extern enum print_line_t
 718trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 719extern void graph_trace_open(struct trace_iterator *iter);
 720extern void graph_trace_close(struct trace_iterator *iter);
 721extern int __trace_graph_entry(struct trace_array *tr,
 722                               struct ftrace_graph_ent *trace,
 723                               unsigned long flags, int pc);
 724extern void __trace_graph_return(struct trace_array *tr,
 725                                 struct ftrace_graph_ret *trace,
 726                                 unsigned long flags, int pc);
 727
 728
 729#ifdef CONFIG_DYNAMIC_FTRACE
 730/* TODO: make this variable */
 731#define FTRACE_GRAPH_MAX_FUNCS          32
 732extern int ftrace_graph_filter_enabled;
 733extern int ftrace_graph_count;
 734extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 735
 736static inline int ftrace_graph_addr(unsigned long addr)
 737{
 738        int i;
 739
 740        if (!ftrace_graph_filter_enabled)
 741                return 1;
 742
 743        for (i = 0; i < ftrace_graph_count; i++) {
 744                if (addr == ftrace_graph_funcs[i]) {
 745                        /*
 746                         * If no irqs are to be traced, but a set_graph_function
 747                         * is set, and called by an interrupt handler, we still
 748                         * want to trace it.
 749                         */
 750                        if (in_irq())
 751                                trace_recursion_set(TRACE_IRQ_BIT);
 752                        else
 753                                trace_recursion_clear(TRACE_IRQ_BIT);
 754                        return 1;
 755                }
 756        }
 757
 758        return 0;
 759}
 760#else
 761static inline int ftrace_graph_addr(unsigned long addr)
 762{
 763        return 1;
 764}
 765#endif /* CONFIG_DYNAMIC_FTRACE */
 766#else /* CONFIG_FUNCTION_GRAPH_TRACER */
 767static inline enum print_line_t
 768print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 769{
 770        return TRACE_TYPE_UNHANDLED;
 771}
 772#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 773
 774extern struct list_head ftrace_pids;
 775
 776#ifdef CONFIG_FUNCTION_TRACER
 777static inline int ftrace_trace_task(struct task_struct *task)
 778{
 779        if (list_empty(&ftrace_pids))
 780                return 1;
 781
 782        return test_tsk_trace_trace(task);
 783}
 784extern int ftrace_is_dead(void);
 785#else
 786static inline int ftrace_trace_task(struct task_struct *task)
 787{
 788        return 1;
 789}
 790static inline int ftrace_is_dead(void) { return 0; }
 791#endif
 792
 793int ftrace_event_is_function(struct ftrace_event_call *call);
 794
 795/*
 796 * struct trace_parser - servers for reading the user input separated by spaces
 797 * @cont: set if the input is not complete - no final space char was found
 798 * @buffer: holds the parsed user input
 799 * @idx: user input length
 800 * @size: buffer size
 801 */
 802struct trace_parser {
 803        bool            cont;
 804        char            *buffer;
 805        unsigned        idx;
 806        unsigned        size;
 807};
 808
 809static inline bool trace_parser_loaded(struct trace_parser *parser)
 810{
 811        return (parser->idx != 0);
 812}
 813
 814static inline bool trace_parser_cont(struct trace_parser *parser)
 815{
 816        return parser->cont;
 817}
 818
 819static inline void trace_parser_clear(struct trace_parser *parser)
 820{
 821        parser->cont = false;
 822        parser->idx = 0;
 823}
 824
 825extern int trace_parser_get_init(struct trace_parser *parser, int size);
 826extern void trace_parser_put(struct trace_parser *parser);
 827extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 828        size_t cnt, loff_t *ppos);
 829
 830/*
 831 * trace_iterator_flags is an enumeration that defines bit
 832 * positions into trace_flags that controls the output.
 833 *
 834 * NOTE: These bits must match the trace_options array in
 835 *       trace.c.
 836 */
 837enum trace_iterator_flags {
 838        TRACE_ITER_PRINT_PARENT         = 0x01,
 839        TRACE_ITER_SYM_OFFSET           = 0x02,
 840        TRACE_ITER_SYM_ADDR             = 0x04,
 841        TRACE_ITER_VERBOSE              = 0x08,
 842        TRACE_ITER_RAW                  = 0x10,
 843        TRACE_ITER_HEX                  = 0x20,
 844        TRACE_ITER_BIN                  = 0x40,
 845        TRACE_ITER_BLOCK                = 0x80,
 846        TRACE_ITER_STACKTRACE           = 0x100,
 847        TRACE_ITER_PRINTK               = 0x200,
 848        TRACE_ITER_PREEMPTONLY          = 0x400,
 849        TRACE_ITER_BRANCH               = 0x800,
 850        TRACE_ITER_ANNOTATE             = 0x1000,
 851        TRACE_ITER_USERSTACKTRACE       = 0x2000,
 852        TRACE_ITER_SYM_USEROBJ          = 0x4000,
 853        TRACE_ITER_PRINTK_MSGONLY       = 0x8000,
 854        TRACE_ITER_CONTEXT_INFO         = 0x10000, /* Print pid/cpu/time */
 855        TRACE_ITER_LATENCY_FMT          = 0x20000,
 856        TRACE_ITER_SLEEP_TIME           = 0x40000,
 857        TRACE_ITER_GRAPH_TIME           = 0x80000,
 858        TRACE_ITER_RECORD_CMD           = 0x100000,
 859        TRACE_ITER_OVERWRITE            = 0x200000,
 860        TRACE_ITER_STOP_ON_FREE         = 0x400000,
 861        TRACE_ITER_IRQ_INFO             = 0x800000,
 862        TRACE_ITER_MARKERS              = 0x1000000,
 863        TRACE_ITER_FUNCTION             = 0x2000000,
 864};
 865
 866/*
 867 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 868 * control the output of kernel symbols.
 869 */
 870#define TRACE_ITER_SYM_MASK \
 871        (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 872
 873extern struct tracer nop_trace;
 874
 875#ifdef CONFIG_BRANCH_TRACER
 876extern int enable_branch_tracing(struct trace_array *tr);
 877extern void disable_branch_tracing(void);
 878static inline int trace_branch_enable(struct trace_array *tr)
 879{
 880        if (trace_flags & TRACE_ITER_BRANCH)
 881                return enable_branch_tracing(tr);
 882        return 0;
 883}
 884static inline void trace_branch_disable(void)
 885{
 886        /* due to races, always disable */
 887        disable_branch_tracing();
 888}
 889#else
 890static inline int trace_branch_enable(struct trace_array *tr)
 891{
 892        return 0;
 893}
 894static inline void trace_branch_disable(void)
 895{
 896}
 897#endif /* CONFIG_BRANCH_TRACER */
 898
 899/* set ring buffers to default size if not already done so */
 900int tracing_update_buffers(void);
 901
 902/* trace event type bit fields, not numeric */
 903enum {
 904        TRACE_EVENT_TYPE_PRINTF         = 1,
 905        TRACE_EVENT_TYPE_RAW            = 2,
 906};
 907
 908struct ftrace_event_field {
 909        struct list_head        link;
 910        const char              *name;
 911        const char              *type;
 912        int                     filter_type;
 913        int                     offset;
 914        int                     size;
 915        int                     is_signed;
 916};
 917
 918struct event_filter {
 919        int                     n_preds;        /* Number assigned */
 920        int                     a_preds;        /* allocated */
 921        struct filter_pred      *preds;
 922        struct filter_pred      *root;
 923        char                    *filter_string;
 924};
 925
 926struct event_subsystem {
 927        struct list_head        list;
 928        const char              *name;
 929        struct event_filter     *filter;
 930        int                     ref_count;
 931};
 932
 933struct ftrace_subsystem_dir {
 934        struct list_head                list;
 935        struct event_subsystem          *subsystem;
 936        struct trace_array              *tr;
 937        struct dentry                   *entry;
 938        int                             ref_count;
 939        int                             nr_events;
 940};
 941
 942#define FILTER_PRED_INVALID     ((unsigned short)-1)
 943#define FILTER_PRED_IS_RIGHT    (1 << 15)
 944#define FILTER_PRED_FOLD        (1 << 15)
 945
 946/*
 947 * The max preds is the size of unsigned short with
 948 * two flags at the MSBs. One bit is used for both the IS_RIGHT
 949 * and FOLD flags. The other is reserved.
 950 *
 951 * 2^14 preds is way more than enough.
 952 */
 953#define MAX_FILTER_PRED         16384
 954
 955struct filter_pred;
 956struct regex;
 957
 958typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
 959
 960typedef int (*regex_match_func)(char *str, struct regex *r, int len);
 961
 962enum regex_type {
 963        MATCH_FULL = 0,
 964        MATCH_FRONT_ONLY,
 965        MATCH_MIDDLE_ONLY,
 966        MATCH_END_ONLY,
 967};
 968
 969struct regex {
 970        char                    pattern[MAX_FILTER_STR_VAL];
 971        int                     len;
 972        int                     field_len;
 973        regex_match_func        match;
 974};
 975
 976struct filter_pred {
 977        filter_pred_fn_t        fn;
 978        u64                     val;
 979        struct regex            regex;
 980        unsigned short          *ops;
 981        struct ftrace_event_field *field;
 982        int                     offset;
 983        int                     not;
 984        int                     op;
 985        unsigned short          index;
 986        unsigned short          parent;
 987        unsigned short          left;
 988        unsigned short          right;
 989};
 990
 991extern enum regex_type
 992filter_parse_regex(char *buff, int len, char **search, int *not);
 993extern void print_event_filter(struct ftrace_event_call *call,
 994                               struct trace_seq *s);
 995extern int apply_event_filter(struct ftrace_event_call *call,
 996                              char *filter_string);
 997extern int apply_subsystem_event_filter(struct ftrace_subsystem_dir *dir,
 998                                        char *filter_string);
 999extern void print_subsystem_event_filter(struct event_subsystem *system,
1000                                         struct trace_seq *s);
1001extern int filter_assign_type(const char *type);
1002
1003struct ftrace_event_field *
1004trace_find_event_field(struct ftrace_event_call *call, char *name);
1005
1006static inline int
1007filter_check_discard(struct ftrace_event_call *call, void *rec,
1008                     struct ring_buffer *buffer,
1009                     struct ring_buffer_event *event)
1010{
1011        if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
1012            !filter_match_preds(call->filter, rec)) {
1013                ring_buffer_discard_commit(buffer, event);
1014                return 1;
1015        }
1016
1017        return 0;
1018}
1019
1020extern void trace_event_enable_cmd_record(bool enable);
1021extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
1022extern int event_trace_del_tracer(struct trace_array *tr);
1023
1024extern struct mutex event_mutex;
1025extern struct list_head ftrace_events;
1026
1027extern const char *__start___trace_bprintk_fmt[];
1028extern const char *__stop___trace_bprintk_fmt[];
1029
1030void trace_printk_init_buffers(void);
1031void trace_printk_start_comm(void);
1032int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
1033int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
1034
1035/*
1036 * Normal trace_printk() and friends allocates special buffers
1037 * to do the manipulation, as well as saves the print formats
1038 * into sections to display. But the trace infrastructure wants
1039 * to use these without the added overhead at the price of being
1040 * a bit slower (used mainly for warnings, where we don't care
1041 * about performance). The internal_trace_puts() is for such
1042 * a purpose.
1043 */
1044#define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
1045
1046#undef FTRACE_ENTRY
1047#define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter)     \
1048        extern struct ftrace_event_call                                 \
1049        __attribute__((__aligned__(4))) event_##call;
1050#undef FTRACE_ENTRY_DUP
1051#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter) \
1052        FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
1053                     filter)
1054#include "trace_entries.h"
1055
1056#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
1057int perf_ftrace_event_register(struct ftrace_event_call *call,
1058                               enum trace_reg type, void *data);
1059#else
1060#define perf_ftrace_event_register NULL
1061#endif
1062
1063#endif /* _LINUX_KERNEL_TRACE_H */
1064