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 trace_buffer;
  12 struct tracer;
  13 struct dentry;
  14
  15 struct trace_print_flags {
  16         unsigned long           mask;
  17         const char              *name;
  18 };
  19
  20 struct trace_print_flags_u64 {
  21         unsigned long long      mask;
  22         const char              *name;
  23 };
  24
  25 const 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
  29 const 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
  33 const 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
  39 const char *ftrace_print_hex_seq(struct trace_seq *p,
  40                                  const unsigned char *buf, int len);
  41
  42 struct trace_iterator;
  43 struct trace_event;
  44
  45 int 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  */
  54 struct 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  */
  68 struct 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
  99 enum trace_iter_flags {
 100         TRACE_FILE_LAT_FMT      = 1,
 101         TRACE_FILE_ANNOTATE     = 2,
 102         TRACE_FILE_TIME_IN_NS   = 4,
 103 };
 104
 105
 106 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
 107                                       int flags, struct trace_event *event);
 108
 109 struct 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
 116 struct trace_event {
 117         struct hlist_node               node;
 118         struct list_head                list;
 119         int                             type;
 120         struct trace_event_functions    *funcs;
 121 };
 122
 123 extern int register_ftrace_event(struct trace_event *event);
 124 extern int unregister_ftrace_event(struct trace_event *event);
 125
 126 /* Return values for print_line callback */
 127 enum 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
 134 void tracing_generic_entry_update(struct trace_entry *entry,
 135                                   unsigned long flags,
 136                                   int pc);
 137 struct ftrace_event_file;
 138
 139 struct ring_buffer_event *
 140 trace_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);
 144 struct ring_buffer_event *
 145 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 146                                   int type, unsigned long len,
 147                                   unsigned long flags, int pc);
 148 void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
 149                                         struct ring_buffer_event *event,
 150                                         unsigned long flags, int pc);
 151 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
 152                                 struct ring_buffer_event *event,
 153                                 unsigned long flags, int pc);
 154 void 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);
 158 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 159                                          struct ring_buffer_event *event);
 160
 161 void tracing_record_cmdline(struct task_struct *tsk);
 162
 163 struct event_filter;
 164
 165 enum 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
 178 struct ftrace_event_call;
 179
 180 struct 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
 194 extern int ftrace_event_reg(struct ftrace_event_call *event,
 195                             enum trace_reg type, void *data);
 196
 197 enum {
 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  */
 215 enum {
 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
 223 struct 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
 248 struct trace_array;
 249 struct ftrace_subsystem_dir;
 250
 251 enum {
 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  */
 266 enum {
 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
 273 struct 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
 311 extern void destroy_preds(struct ftrace_event_call *call);
 312 extern int filter_match_preds(struct event_filter *filter, void *rec);
 313 extern 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
 318 enum {
 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
 327 extern struct mutex event_storage_mutex;
 328 extern char event_storage[EVENT_STORAGE_SIZE];
 329
 330 extern int trace_event_raw_init(struct ftrace_event_call *call);
 331 extern 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);
 334 extern int trace_add_event_call(struct ftrace_event_call *call);
 335 extern void trace_remove_event_call(struct ftrace_event_call *call);
 336
 337 #define is_signed_type(type)    (((type)(-1)) < (type)1)
 338
 339 int 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...)                            \
 347 do {                                                                    \
 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
 361 struct perf_event;
 362
 363 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 364
 365 extern int  perf_trace_init(struct perf_event *event);
 366 extern void perf_trace_destroy(struct perf_event *event);
 367 extern int  perf_trace_add(struct perf_event *event, int flags);
 368 extern void perf_trace_del(struct perf_event *event, int flags);
 369 extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 370                                      char *filter_str);
 371 extern void ftrace_profile_free_filter(struct perf_event *event);
 372 extern void *perf_trace_buf_prepare(int size, unsigned short type,
 373                                     struct pt_regs *regs, int *rctxp);
 374
 375 static inline void
 376 perf_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 */