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