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[NR_CPUS];
  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                     cpu;
  80         u64                     ts;
  81
  82         loff_t                  pos;
  83         long                    idx;
  84
  85         cpumask_var_t           started;
  86 };
  87
  88
  89 struct trace_event;
  90
  91 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  92                                       int flags, struct trace_event *event);
  93
  94 struct trace_event_functions {
  95         trace_print_func        trace;
  96         trace_print_func        raw;
  97         trace_print_func        hex;
  98         trace_print_func        binary;
  99 };
 100
 101 struct trace_event {
 102         struct hlist_node               node;
 103         struct list_head                list;
 104         int                             type;
 105         struct trace_event_functions    *funcs;
 106 };
 107
 108 extern int register_ftrace_event(struct trace_event *event);
 109 extern int unregister_ftrace_event(struct trace_event *event);
 110
 111 /* Return values for print_line callback */
 112 enum print_line_t {
 113         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 114         TRACE_TYPE_HANDLED      = 1,
 115         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 116         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 117 };
 118
 119 void tracing_generic_entry_update(struct trace_entry *entry,
 120                                   unsigned long flags,
 121                                   int pc);
 122 struct ring_buffer_event *
 123 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 124                                   int type, unsigned long len,
 125                                   unsigned long flags, int pc);
 126 void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
 127                                         struct ring_buffer_event *event,
 128                                         unsigned long flags, int pc);
 129 void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
 130                                        struct ring_buffer_event *event,
 131                                         unsigned long flags, int pc);
 132 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 133                                          struct ring_buffer_event *event);
 134
 135 void tracing_record_cmdline(struct task_struct *tsk);
 136
 137 struct event_filter;
 138
 139 enum trace_reg {
 140         TRACE_REG_REGISTER,
 141         TRACE_REG_UNREGISTER,
 142         TRACE_REG_PERF_REGISTER,
 143         TRACE_REG_PERF_UNREGISTER,
 144 };
 145
 146 struct ftrace_event_call;
 147
 148 struct ftrace_event_class {
 149         char                    *system;
 150         void                    *probe;
 151 #ifdef CONFIG_PERF_EVENTS
 152         void                    *perf_probe;
 153 #endif
 154         int                     (*reg)(struct ftrace_event_call *event,
 155                                        enum trace_reg type);
 156         int                     (*define_fields)(struct ftrace_event_call *);
 157         struct list_head        *(*get_fields)(struct ftrace_event_call *);
 158         struct list_head        fields;
 159         int                     (*raw_init)(struct ftrace_event_call *);
 160 };
 161
 162 extern int ftrace_event_reg(struct ftrace_event_call *event,
 163                             enum trace_reg type);
 164
 165 enum {
 166         TRACE_EVENT_FL_ENABLED_BIT,
 167         TRACE_EVENT_FL_FILTERED_BIT,
 168         TRACE_EVENT_FL_RECORDED_CMD_BIT,
 169         TRACE_EVENT_FL_CAP_ANY_BIT,
 170 };
 171
 172 enum {
 173         TRACE_EVENT_FL_ENABLED          = (1 << TRACE_EVENT_FL_ENABLED_BIT),
 174         TRACE_EVENT_FL_FILTERED         = (1 << TRACE_EVENT_FL_FILTERED_BIT),
 175         TRACE_EVENT_FL_RECORDED_CMD     = (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),
 176         TRACE_EVENT_FL_CAP_ANY          = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
 177 };
 178
 179 struct ftrace_event_call {
 180         struct list_head        list;
 181         struct ftrace_event_class *class;
 182         char                    *name;
 183         struct dentry           *dir;
 184         struct trace_event      event;
 185         const char              *print_fmt;
 186         struct event_filter     *filter;
 187         void                    *mod;
 188         void                    *data;
 189
 190         /*
 191          * 32 bit flags:
 192          *   bit 1:             enabled
 193          *   bit 2:             filter_active
 194          *   bit 3:             enabled cmd record
 195          *
 196          * Changes to flags must hold the event_mutex.
 197          *
 198          * Note: Reads of flags do not hold the event_mutex since
 199          * they occur in critical sections. But the way flags
 200          * is currently used, these changes do no affect the code
 201          * except that when a change is made, it may have a slight
 202          * delay in propagating the changes to other CPUs due to
 203          * caching and such.
 204          */
 205         unsigned int            flags;
 206
 207 #ifdef CONFIG_PERF_EVENTS
 208         int                             perf_refcount;
 209         struct hlist_head __percpu      *perf_events;
 210 #endif
 211 };
 212
 213 #define __TRACE_EVENT_FLAGS(name, value)                                \
 214         static int __init trace_init_flags_##name(void)                 \
 215         {                                                               \
 216                 event_##name.flags = value;                             \
 217                 return 0;                                               \
 218         }                                                               \
 219         early_initcall(trace_init_flags_##name);
 220
 221 #define PERF_MAX_TRACE_SIZE     2048
 222
 223 #define MAX_FILTER_STR_VAL      256     /* Should handle KSYM_SYMBOL_LEN */
 224
 225 extern void destroy_preds(struct ftrace_event_call *call);
 226 extern int filter_match_preds(struct event_filter *filter, void *rec);
 227 extern int filter_current_check_discard(struct ring_buffer *buffer,
 228                                         struct ftrace_event_call *call,
 229                                         void *rec,
 230                                         struct ring_buffer_event *event);
 231
 232 enum {
 233         FILTER_OTHER = 0,
 234         FILTER_STATIC_STRING,
 235         FILTER_DYN_STRING,
 236         FILTER_PTR_STRING,
 237 };
 238
 239 #define EVENT_STORAGE_SIZE 128
 240 extern struct mutex event_storage_mutex;
 241 extern char event_storage[EVENT_STORAGE_SIZE];
 242
 243 extern int trace_event_raw_init(struct ftrace_event_call *call);
 244 extern int trace_define_field(struct ftrace_event_call *call, const char *type,
 245                               const char *name, int offset, int size,
 246                               int is_signed, int filter_type);
 247 extern int trace_add_event_call(struct ftrace_event_call *call);
 248 extern void trace_remove_event_call(struct ftrace_event_call *call);
 249
 250 #define is_signed_type(type)    (((type)(-1)) < 0)
 251
 252 int trace_set_clr_event(const char *system, const char *event, int set);
 253
 254 /*
 255  * The double __builtin_constant_p is because gcc will give us an error
 256  * if we try to allocate the static variable to fmt if it is not a
 257  * constant. Even with the outer if statement optimizing out.
 258  */
 259 #define event_trace_printk(ip, fmt, args...)                            \
 260 do {                                                                    \
 261         __trace_printk_check_format(fmt, ##args);                       \
 262         tracing_record_cmdline(current);                                \
 263         if (__builtin_constant_p(fmt)) {                                \
 264                 static const char *trace_printk_fmt                     \
 265                   __attribute__((section("__trace_printk_fmt"))) =      \
 266                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 267                                                                         \
 268                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 269         } else                                                          \
 270                 __trace_printk(ip, fmt, ##args);                        \
 271 } while (0)
 272
 273 #ifdef CONFIG_PERF_EVENTS
 274 struct perf_event;
 275
 276 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 277
 278 extern int  perf_trace_init(struct perf_event *event);
 279 extern void perf_trace_destroy(struct perf_event *event);
 280 extern int  perf_trace_add(struct perf_event *event, int flags);
 281 extern void perf_trace_del(struct perf_event *event, int flags);
 282 extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 283                                      char *filter_str);
 284 extern void ftrace_profile_free_filter(struct perf_event *event);
 285 extern void *perf_trace_buf_prepare(int size, unsigned short type,
 286                                     struct pt_regs *regs, int *rctxp);
 287
 288 static inline void
 289 perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
 290                        u64 count, struct pt_regs *regs, void *head)
 291 {
 292         perf_tp_event(addr, count, raw_data, size, regs, head, rctx);
 293 }
 294 #endif
 295
 296 #endif /* _LINUX_FTRACE_EVENT_H */