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 /*
  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  */
  47 struct 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  */
  62 struct 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
  90 struct trace_event;
  91
  92 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  93                                       int flags, struct trace_event *event);
  94
  95 struct 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
 102 struct trace_event {
 103         struct hlist_node               node;
 104         struct list_head                list;
 105         int                             type;
 106         struct trace_event_functions    *funcs;
 107 };
 108
 109 extern int register_ftrace_event(struct trace_event *event);
 110 extern int unregister_ftrace_event(struct trace_event *event);
 111
 112 /* Return values for print_line callback */
 113 enum 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
 120 void tracing_generic_entry_update(struct trace_entry *entry,
 121                                   unsigned long flags,
 122                                   int pc);
 123 struct ring_buffer_event *
 124 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 125                                   int type, unsigned long len,
 126                                   unsigned long flags, int pc);
 127 void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
 128                                         struct ring_buffer_event *event,
 129                                         unsigned long flags, int pc);
 130 void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
 131                                        struct ring_buffer_event *event,
 132                                         unsigned long flags, int pc);
 133 void 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);
 137 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 138                                          struct ring_buffer_event *event);
 139
 140 void tracing_record_cmdline(struct task_struct *tsk);
 141
 142 struct event_filter;
 143
 144 enum 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
 157 struct ftrace_event_call;
 158
 159 struct 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
 173 extern int ftrace_event_reg(struct ftrace_event_call *event,
 174                             enum trace_reg type, void *data);
 175
 176 enum {
 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
 185 enum {
 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
 194 struct 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
 243 extern void destroy_preds(struct ftrace_event_call *call);
 244 extern int filter_match_preds(struct event_filter *filter, void *rec);
 245 extern 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
 250 enum {
 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
 259 extern struct mutex event_storage_mutex;
 260 extern char event_storage[EVENT_STORAGE_SIZE];
 261
 262 extern int trace_event_raw_init(struct ftrace_event_call *call);
 263 extern 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);
 266 extern int trace_add_event_call(struct ftrace_event_call *call);
 267 extern void trace_remove_event_call(struct ftrace_event_call *call);
 268
 269 #define is_signed_type(type)    (((type)(-1)) < 0)
 270
 271 int 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...)                            \
 279 do {                                                                    \
 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
 293 struct perf_event;
 294
 295 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 296
 297 extern int  perf_trace_init(struct perf_event *event);
 298 extern void perf_trace_destroy(struct perf_event *event);
 299 extern int  perf_trace_add(struct perf_event *event, int flags);
 300 extern void perf_trace_del(struct perf_event *event, int flags);
 301 extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 302                                      char *filter_str);
 303 extern void ftrace_profile_free_filter(struct perf_event *event);
 304 extern void *perf_trace_buf_prepare(int size, unsigned short type,
 305                                     struct pt_regs *regs, int *rctxp);
 306
 307 static inline void
 308 perf_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 */