include/linux/ftrace_event.h

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