LXR linux/include/linux/ftrace

   1#ifndef _LINUX_FTRACE_EVENT_H
   2#define _LINUX_FTRACE_EVENT_H
   3
   4#include <linux/ring_buffer.h>
   5#include <linux/trace_seq.h>
   6#include <linux/percpu.h>
   7#include <linux/hardirq.h>
   8#include <linux/perf_event.h>
   9
  10struct trace_array;
  11struct trace_buffer;
  12struct tracer;
  13struct dentry;
  14
  15struct trace_print_flags {
  16        unsigned long           mask;
  17        const char              *name;
  18};
  19
  20struct trace_print_flags_u64 {
  21        unsigned long long      mask;
  22        const char              *name;
  23};
  24
  25const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
  26                                   unsigned long flags,
  27                                   const struct trace_print_flags *flag_array);
  28
  29const char *ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
  30                                     const struct trace_print_flags *symbol_array);
  31
  32#if BITS_PER_LONG == 32
  33const char *ftrace_print_symbols_seq_u64(struct trace_seq *p,
  34                                         unsigned long long val,
  35                                         const struct trace_print_flags_u64
  36                                                                 *symbol_array);
  37#endif
  38
  39const char *ftrace_print_hex_seq(struct trace_seq *p,
  40                                 const unsigned char *buf, int len);
  41
  42struct trace_iterator;
  43struct trace_event;
  44
  45int ftrace_raw_output_prep(struct trace_iterator *iter,
  46                           struct trace_event *event);
  47
  48/*
  49 * The trace entry - the most basic unit of tracing. This is what
  50 * is printed in the end as a single line in the trace output, such as:
  51 *
  52 *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  53 */
  54struct trace_entry {
  55        unsigned short          type;
  56        unsigned char           flags;
  57        unsigned char           preempt_count;
  58        int                     pid;
  59};
  60
  61#define FTRACE_MAX_EVENT                                                \
  62        ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  63
  64/*
  65 * Trace iterator - used by printout routines who present trace
  66 * results to users and which routines might sleep, etc:
  67 */
  68struct trace_iterator {
  69        struct trace_array      *tr;
  70        struct tracer           *trace;
  71        struct trace_buffer     *trace_buffer;
  72        void                    *private;
  73        int                     cpu_file;
  74        struct mutex            mutex;
  75        struct ring_buffer_iter **buffer_iter;
  76        unsigned long           iter_flags;
  77
  78        /* trace_seq for __print_flags() and __print_symbolic() etc. */
  79        struct trace_seq        tmp_seq;
  80
  81        /* The below is zeroed out in pipe_read */
  82        struct trace_seq        seq;
  83        struct trace_entry      *ent;
  84        unsigned long           lost_events;
  85        int                     leftover;
  86        int                     ent_size;
  87        int                     cpu;
  88        u64                     ts;
  89
  90        loff_t                  pos;
  91        long                    idx;
  92
  93        cpumask_var_t           started;
  94
  95        /* it's true when current open file is snapshot */
  96        bool                    snapshot;
  97};
  98
  99enum trace_iter_flags {
 100        TRACE_FILE_LAT_FMT      = 1,
 101        TRACE_FILE_ANNOTATE     = 2,
 102        TRACE_FILE_TIME_IN_NS   = 4,
 103};
 104
 105
 106typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
 107                                      int flags, struct trace_event *event);
 108
 109struct trace_event_functions {
 110        trace_print_func        trace;
 111        trace_print_func        raw;
 112        trace_print_func        hex;
 113        trace_print_func        binary;
 114};
 115
 116struct trace_event {
 117        struct hlist_node               node;
 118        struct list_head                list;
 119        int                             type;
 120        struct trace_event_functions    *funcs;
 121};
 122
 123extern int register_ftrace_event(struct trace_event *event);
 124extern int unregister_ftrace_event(struct trace_event *event);
 125
 126/* Return values for print_line callback */
 127enum print_line_t {
 128        TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 129        TRACE_TYPE_HANDLED      = 1,
 130        TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 131        TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 132};
 133
 134void tracing_generic_entry_update(struct trace_entry *entry,
 135                                  unsigned long flags,
 136                                  int pc);
 137struct ftrace_event_file;
 138
 139struct ring_buffer_event *
 140trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer,
 141                                struct ftrace_event_file *ftrace_file,
 142                                int type, unsigned long len,
 143                                unsigned long flags, int pc);
 144struct ring_buffer_event *
 145trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 146                                  int type, unsigned long len,
 147                                  unsigned long flags, int pc);
 148void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
 149                                        struct ring_buffer_event *event,
 150                                        unsigned long flags, int pc);
 151void trace_buffer_unlock_commit(struct ring_buffer *buffer,
 152                                struct ring_buffer_event *event,
 153                                unsigned long flags, int pc);
 154void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer,
 155                                     struct ring_buffer_event *event,
 156                                     unsigned long flags, int pc,
 157                                     struct pt_regs *regs);
 158void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 159                                         struct ring_buffer_event *event);
 160
 161void tracing_record_cmdline(struct task_struct *tsk);
 162
 163struct event_filter;
 164
 165enum trace_reg {
 166        TRACE_REG_REGISTER,
 167        TRACE_REG_UNREGISTER,
 168#ifdef CONFIG_PERF_EVENTS
 169        TRACE_REG_PERF_REGISTER,
 170        TRACE_REG_PERF_UNREGISTER,
 171        TRACE_REG_PERF_OPEN,
 172        TRACE_REG_PERF_CLOSE,
 173        TRACE_REG_PERF_ADD,
 174        TRACE_REG_PERF_DEL,
 175#endif
 176};
 177
 178struct ftrace_event_call;
 179
 180struct ftrace_event_class {
 181        char                    *system;
 182        void                    *probe;
 183#ifdef CONFIG_PERF_EVENTS
 184        void                    *perf_probe;
 185#endif
 186        int                     (*reg)(struct ftrace_event_call *event,
 187                                       enum trace_reg type, void *data);
 188        int                     (*define_fields)(struct ftrace_event_call *);
 189        struct list_head        *(*get_fields)(struct ftrace_event_call *);
 190        struct list_head        fields;
 191        int                     (*raw_init)(struct ftrace_event_call *);
 192};
 193
 194extern int ftrace_event_reg(struct ftrace_event_call *event,
 195                            enum trace_reg type, void *data);
 196
 197enum {
 198        TRACE_EVENT_FL_FILTERED_BIT,
 199        TRACE_EVENT_FL_CAP_ANY_BIT,
 200        TRACE_EVENT_FL_NO_SET_FILTER_BIT,
 201        TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
 202        TRACE_EVENT_FL_WAS_ENABLED_BIT,
 203};
 204
 205/*
 206 * Event flags:
 207 *  FILTERED      - The event has a filter attached
 208 *  CAP_ANY       - Any user can enable for perf
 209 *  NO_SET_FILTER - Set when filter has error and is to be ignored
 210 *  IGNORE_ENABLE - For ftrace internal events, do not enable with debugfs file
 211 *  WAS_ENABLED   - Set and stays set when an event was ever enabled
 212 *                    (used for module unloading, if a module event is enabled,
 213 *                     it is best to clear the buffers that used it).
 214 */
 215enum {
 216        TRACE_EVENT_FL_FILTERED         = (1 << TRACE_EVENT_FL_FILTERED_BIT),
 217        TRACE_EVENT_FL_CAP_ANY          = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
 218        TRACE_EVENT_FL_NO_SET_FILTER    = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
 219        TRACE_EVENT_FL_IGNORE_ENABLE    = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
 220        TRACE_EVENT_FL_WAS_ENABLED      = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT),
 221};
 222
 223struct ftrace_event_call {
 224        struct list_head        list;
 225        struct ftrace_event_class *class;
 226        char                    *name;
 227        struct trace_event      event;
 228        const char              *print_fmt;
 229        struct event_filter     *filter;
 230        struct list_head        *files;
 231        void                    *mod;
 232        void                    *data;
 233        /*
 234         *   bit 0:             filter_active
 235         *   bit 1:             allow trace by non root (cap any)
 236         *   bit 2:             failed to apply filter
 237         *   bit 3:             ftrace internal event (do not enable)
 238         *   bit 4:             Event was enabled by module
 239         */
 240        int                     flags; /* static flags of different events */
 241
 242#ifdef CONFIG_PERF_EVENTS
 243        int                             perf_refcount;
 244        struct hlist_head __percpu      *perf_events;
 245#endif
 246};
 247
 248struct trace_array;
 249struct ftrace_subsystem_dir;
 250
 251enum {
 252        FTRACE_EVENT_FL_ENABLED_BIT,
 253        FTRACE_EVENT_FL_RECORDED_CMD_BIT,
 254        FTRACE_EVENT_FL_SOFT_MODE_BIT,
 255        FTRACE_EVENT_FL_SOFT_DISABLED_BIT,
 256};
 257
 258/*
 259 * Ftrace event file flags:
 260 *  ENABLED       - The event is enabled
 261 *  RECORDED_CMD  - The comms should be recorded at sched_switch
 262 *  SOFT_MODE     - The event is enabled/disabled by SOFT_DISABLED
 263 *  SOFT_DISABLED - When set, do not trace the event (even though its
 264 *                   tracepoint may be enabled)
 265 */
 266enum {
 267        FTRACE_EVENT_FL_ENABLED         = (1 << FTRACE_EVENT_FL_ENABLED_BIT),
 268        FTRACE_EVENT_FL_RECORDED_CMD    = (1 << FTRACE_EVENT_FL_RECORDED_CMD_BIT),
 269        FTRACE_EVENT_FL_SOFT_MODE       = (1 << FTRACE_EVENT_FL_SOFT_MODE_BIT),
 270        FTRACE_EVENT_FL_SOFT_DISABLED   = (1 << FTRACE_EVENT_FL_SOFT_DISABLED_BIT),
 271};
 272
 273struct ftrace_event_file {
 274        struct list_head                list;
 275        struct ftrace_event_call        *event_call;
 276        struct dentry                   *dir;
 277        struct trace_array              *tr;
 278        struct ftrace_subsystem_dir     *system;
 279
 280        /*
 281         * 32 bit flags:
 282         *   bit 0:             enabled
 283         *   bit 1:             enabled cmd record
 284         *   bit 2:             enable/disable with the soft disable bit
 285         *   bit 3:             soft disabled
 286         *
 287         * Note: The bits must be set atomically to prevent races
 288         * from other writers. Reads of flags do not need to be in
 289         * sync as they occur in critical sections. But the way flags
 290         * is currently used, these changes do not affect the code
 291         * except that when a change is made, it may have a slight
 292         * delay in propagating the changes to other CPUs due to
 293         * caching and such. Which is mostly OK ;-)
 294         */
 295        unsigned long           flags;
 296        atomic_t                sm_ref; /* soft-mode reference counter */
 297};
 298
 299#define __TRACE_EVENT_FLAGS(name, value)                                \
 300        static int __init trace_init_flags_##name(void)                 \
 301        {                                                               \
 302                event_##name.flags = value;                             \
 303                return 0;                                               \
 304        }                                                               \
 305        early_initcall(trace_init_flags_##name);
 306
 307#define PERF_MAX_TRACE_SIZE     2048
 308
 309#define MAX_FILTER_STR_VAL      256     /* Should handle KSYM_SYMBOL_LEN */
 310
 311extern void destroy_preds(struct ftrace_event_call *call);
 312extern int filter_match_preds(struct event_filter *filter, void *rec);
 313extern int filter_current_check_discard(struct ring_buffer *buffer,
 314                                        struct ftrace_event_call *call,
 315                                        void *rec,
 316                                        struct ring_buffer_event *event);
 317
 318enum {
 319        FILTER_OTHER = 0,
 320        FILTER_STATIC_STRING,
 321        FILTER_DYN_STRING,
 322        FILTER_PTR_STRING,
 323        FILTER_TRACE_FN,
 324};
 325
 326#define EVENT_STORAGE_SIZE 128
 327extern struct mutex event_storage_mutex;
 328extern char event_storage[EVENT_STORAGE_SIZE];
 329
 330extern int trace_event_raw_init(struct ftrace_event_call *call);
 331extern int trace_define_field(struct ftrace_event_call *call, const char *type,
 332                              const char *name, int offset, int size,
 333                              int is_signed, int filter_type);
 334extern int trace_add_event_call(struct ftrace_event_call *call);
 335extern void trace_remove_event_call(struct ftrace_event_call *call);
 336
 337#define is_signed_type(type)    (((type)(-1)) < (type)1)
 338
 339int trace_set_clr_event(const char *system, const char *event, int set);
 340
 341/*
 342 * The double __builtin_constant_p is because gcc will give us an error
 343 * if we try to allocate the static variable to fmt if it is not a
 344 * constant. Even with the outer if statement optimizing out.
 345 */
 346#define event_trace_printk(ip, fmt, args...)                            \
 347do {                                                                    \
 348        __trace_printk_check_format(fmt, ##args);                       \
 349        tracing_record_cmdline(current);                                \
 350        if (__builtin_constant_p(fmt)) {                                \
 351                static const char *trace_printk_fmt                     \
 352                  __attribute__((section("__trace_printk_fmt"))) =      \
 353                        __builtin_constant_p(fmt) ? fmt : NULL;         \
 354                                                                        \
 355                __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 356        } else                                                          \
 357                __trace_printk(ip, fmt, ##args);                        \
 358} while (0)
 359
 360#ifdef CONFIG_PERF_EVENTS
 361struct perf_event;
 362
 363DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 364
 365extern int  perf_trace_init(struct perf_event *event);
 366extern void perf_trace_destroy(struct perf_event *event);
 367extern int  perf_trace_add(struct perf_event *event, int flags);
 368extern void perf_trace_del(struct perf_event *event, int flags);
 369extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 370                                     char *filter_str);
 371extern void ftrace_profile_free_filter(struct perf_event *event);
 372extern void *perf_trace_buf_prepare(int size, unsigned short type,
 373                                    struct pt_regs *regs, int *rctxp);
 374
 375static inline void
 376perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
 377                       u64 count, struct pt_regs *regs, void *head,
 378                       struct task_struct *task)
 379{
 380        perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task);
 381}
 382#endif
 383
 384#endif /* _LINUX_FTRACE_EVENT_H */
 385