linux/include/linux/ftrace_event.h
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   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 tracer;
  12struct dentry;
  13
  14struct trace_print_flags {
  15        unsigned long           mask;
  16        const char              *name;
  17};
  18
  19struct trace_print_flags_u64 {
  20        unsigned long long      mask;
  21        const char              *name;
  22};
  23
  24const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
  25                                   unsigned long flags,
  26                                   const struct trace_print_flags *flag_array);
  27
  28const char *ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
  29                                     const struct trace_print_flags *symbol_array);
  30
  31#if BITS_PER_LONG == 32
  32const char *ftrace_print_symbols_seq_u64(struct trace_seq *p,
  33                                         unsigned long long val,
  34                                         const struct trace_print_flags_u64
  35                                                                 *symbol_array);
  36#endif
  37
  38const char *ftrace_print_hex_seq(struct trace_seq *p,
  39                                 const unsigned char *buf, int len);
  40
  41/*
  42 * The trace entry - the most basic unit of tracing. This is what
  43 * is printed in the end as a single line in the trace output, such as:
  44 *
  45 *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  46 */
  47struct trace_entry {
  48        unsigned short          type;
  49        unsigned char           flags;
  50        unsigned char           preempt_count;
  51        int                     pid;
  52        int                     padding;
  53};
  54
  55#define FTRACE_MAX_EVENT                                                \
  56        ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  57
  58/*
  59 * Trace iterator - used by printout routines who present trace
  60 * results to users and which routines might sleep, etc:
  61 */
  62struct trace_iterator {
  63        struct trace_array      *tr;
  64        struct tracer           *trace;
  65        void                    *private;
  66        int                     cpu_file;
  67        struct mutex            mutex;
  68        struct ring_buffer_iter **buffer_iter;
  69        unsigned long           iter_flags;
  70
  71        /* trace_seq for __print_flags() and __print_symbolic() etc. */
  72        struct trace_seq        tmp_seq;
  73
  74        /* The below is zeroed out in pipe_read */
  75        struct trace_seq        seq;
  76        struct trace_entry      *ent;
  77        unsigned long           lost_events;
  78        int                     leftover;
  79        int                     ent_size;
  80        int                     cpu;
  81        u64                     ts;
  82
  83        loff_t                  pos;
  84        long                    idx;
  85
  86        cpumask_var_t           started;
  87};
  88
  89
  90struct trace_event;
  91
  92typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  93                                      int flags, struct trace_event *event);
  94
  95struct trace_event_functions {
  96        trace_print_func        trace;
  97        trace_print_func        raw;
  98        trace_print_func        hex;
  99        trace_print_func        binary;
 100};
 101
 102struct trace_event {
 103        struct hlist_node               node;
 104        struct list_head                list;
 105        int                             type;
 106        struct trace_event_functions    *funcs;
 107};
 108
 109extern int register_ftrace_event(struct trace_event *event);
 110extern int unregister_ftrace_event(struct trace_event *event);
 111
 112/* Return values for print_line callback */
 113enum print_line_t {
 114        TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 115        TRACE_TYPE_HANDLED      = 1,
 116        TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 117        TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 118};
 119
 120void tracing_generic_entry_update(struct trace_entry *entry,
 121                                  unsigned long flags,
 122                                  int pc);
 123struct ring_buffer_event *
 124trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 125                                  int type, unsigned long len,
 126                                  unsigned long flags, int pc);
 127void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
 128                                        struct ring_buffer_event *event,
 129                                        unsigned long flags, int pc);
 130void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
 131                                       struct ring_buffer_event *event,
 132                                        unsigned long flags, int pc);
 133void trace_nowake_buffer_unlock_commit_regs(struct ring_buffer *buffer,
 134                                            struct ring_buffer_event *event,
 135                                            unsigned long flags, int pc,
 136                                            struct pt_regs *regs);
 137void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 138                                         struct ring_buffer_event *event);
 139
 140void tracing_record_cmdline(struct task_struct *tsk);
 141
 142struct event_filter;
 143
 144enum trace_reg {
 145        TRACE_REG_REGISTER,
 146        TRACE_REG_UNREGISTER,
 147#ifdef CONFIG_PERF_EVENTS
 148        TRACE_REG_PERF_REGISTER,
 149        TRACE_REG_PERF_UNREGISTER,
 150        TRACE_REG_PERF_OPEN,
 151        TRACE_REG_PERF_CLOSE,
 152        TRACE_REG_PERF_ADD,
 153        TRACE_REG_PERF_DEL,
 154#endif
 155};
 156
 157struct ftrace_event_call;
 158
 159struct ftrace_event_class {
 160        char                    *system;
 161        void                    *probe;
 162#ifdef CONFIG_PERF_EVENTS
 163        void                    *perf_probe;
 164#endif
 165        int                     (*reg)(struct ftrace_event_call *event,
 166                                       enum trace_reg type, void *data);
 167        int                     (*define_fields)(struct ftrace_event_call *);
 168        struct list_head        *(*get_fields)(struct ftrace_event_call *);
 169        struct list_head        fields;
 170        int                     (*raw_init)(struct ftrace_event_call *);
 171};
 172
 173extern int ftrace_event_reg(struct ftrace_event_call *event,
 174                            enum trace_reg type, void *data);
 175
 176enum {
 177        TRACE_EVENT_FL_ENABLED_BIT,
 178        TRACE_EVENT_FL_FILTERED_BIT,
 179        TRACE_EVENT_FL_RECORDED_CMD_BIT,
 180        TRACE_EVENT_FL_CAP_ANY_BIT,
 181        TRACE_EVENT_FL_NO_SET_FILTER_BIT,
 182        TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
 183};
 184
 185enum {
 186        TRACE_EVENT_FL_ENABLED          = (1 << TRACE_EVENT_FL_ENABLED_BIT),
 187        TRACE_EVENT_FL_FILTERED         = (1 << TRACE_EVENT_FL_FILTERED_BIT),
 188        TRACE_EVENT_FL_RECORDED_CMD     = (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),
 189        TRACE_EVENT_FL_CAP_ANY          = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
 190        TRACE_EVENT_FL_NO_SET_FILTER    = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
 191        TRACE_EVENT_FL_IGNORE_ENABLE    = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
 192};
 193
 194struct ftrace_event_call {
 195        struct list_head        list;
 196        struct ftrace_event_class *class;
 197        char                    *name;
 198        struct dentry           *dir;
 199        struct trace_event      event;
 200        const char              *print_fmt;
 201        struct event_filter     *filter;
 202        void                    *mod;
 203        void                    *data;
 204
 205        /*
 206         * 32 bit flags:
 207         *   bit 1:             enabled
 208         *   bit 2:             filter_active
 209         *   bit 3:             enabled cmd record
 210         *   bit 4:             allow trace by non root (cap any)
 211         *   bit 5:             failed to apply filter
 212         *   bit 6:             ftrace internal event (do not enable)
 213         *
 214         * Changes to flags must hold the event_mutex.
 215         *
 216         * Note: Reads of flags do not hold the event_mutex since
 217         * they occur in critical sections. But the way flags
 218         * is currently used, these changes do no affect the code
 219         * except that when a change is made, it may have a slight
 220         * delay in propagating the changes to other CPUs due to
 221         * caching and such.
 222         */
 223        unsigned int            flags;
 224
 225#ifdef CONFIG_PERF_EVENTS
 226        int                             perf_refcount;
 227        struct hlist_head __percpu      *perf_events;
 228#endif
 229};
 230
 231#define __TRACE_EVENT_FLAGS(name, value)                                \
 232        static int __init trace_init_flags_##name(void)                 \
 233        {                                                               \
 234                event_##name.flags = value;                             \
 235                return 0;                                               \
 236        }                                                               \
 237        early_initcall(trace_init_flags_##name);
 238
 239#define PERF_MAX_TRACE_SIZE     2048
 240
 241#define MAX_FILTER_STR_VAL      256     /* Should handle KSYM_SYMBOL_LEN */
 242
 243extern void destroy_preds(struct ftrace_event_call *call);
 244extern int filter_match_preds(struct event_filter *filter, void *rec);
 245extern int filter_current_check_discard(struct ring_buffer *buffer,
 246                                        struct ftrace_event_call *call,
 247                                        void *rec,
 248                                        struct ring_buffer_event *event);
 249
 250enum {
 251        FILTER_OTHER = 0,
 252        FILTER_STATIC_STRING,
 253        FILTER_DYN_STRING,
 254        FILTER_PTR_STRING,
 255        FILTER_TRACE_FN,
 256};
 257
 258#define EVENT_STORAGE_SIZE 128
 259extern struct mutex event_storage_mutex;
 260extern char event_storage[EVENT_STORAGE_SIZE];
 261
 262extern int trace_event_raw_init(struct ftrace_event_call *call);
 263extern int trace_define_field(struct ftrace_event_call *call, const char *type,
 264                              const char *name, int offset, int size,
 265                              int is_signed, int filter_type);
 266extern int trace_add_event_call(struct ftrace_event_call *call);
 267extern void trace_remove_event_call(struct ftrace_event_call *call);
 268
 269#define is_signed_type(type)    (((type)(-1)) < 0)
 270
 271int trace_set_clr_event(const char *system, const char *event, int set);
 272
 273/*
 274 * The double __builtin_constant_p is because gcc will give us an error
 275 * if we try to allocate the static variable to fmt if it is not a
 276 * constant. Even with the outer if statement optimizing out.
 277 */
 278#define event_trace_printk(ip, fmt, args...)                            \
 279do {                                                                    \
 280        __trace_printk_check_format(fmt, ##args);                       \
 281        tracing_record_cmdline(current);                                \
 282        if (__builtin_constant_p(fmt)) {                                \
 283                static const char *trace_printk_fmt                     \
 284                  __attribute__((section("__trace_printk_fmt"))) =      \
 285                        __builtin_constant_p(fmt) ? fmt : NULL;         \
 286                                                                        \
 287                __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 288        } else                                                          \
 289                __trace_printk(ip, fmt, ##args);                        \
 290} while (0)
 291
 292#ifdef CONFIG_PERF_EVENTS
 293struct perf_event;
 294
 295DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 296
 297extern int  perf_trace_init(struct perf_event *event);
 298extern void perf_trace_destroy(struct perf_event *event);
 299extern int  perf_trace_add(struct perf_event *event, int flags);
 300extern void perf_trace_del(struct perf_event *event, int flags);
 301extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 302                                     char *filter_str);
 303extern void ftrace_profile_free_filter(struct perf_event *event);
 304extern void *perf_trace_buf_prepare(int size, unsigned short type,
 305                                    struct pt_regs *regs, int *rctxp);
 306
 307static inline void
 308perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
 309                       u64 count, struct pt_regs *regs, void *head,
 310                       struct task_struct *task)
 311{
 312        perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task);
 313}
 314#endif
 315
 316#endif /* _LINUX_FTRACE_EVENT_H */
 317
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