include/linux/ftrace_event.h

   1 #ifndef _LINUX_FTRACE_EVENT_H
   2 #define _LINUX_FTRACE_EVENT_H
   3
   4 #include <linux/trace_seq.h>
   5 #include <linux/ring_buffer.h>
   6
   7
   8 struct trace_array;
   9 struct tracer;
  10 struct dentry;
  11
  12 /*
  13  * The trace entry - the most basic unit of tracing. This is what
  14  * is printed in the end as a single line in the trace output, such as:
  15  *
  16  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  17  */
  18 struct trace_entry {
  19         int                     type;
  20         unsigned char           flags;
  21         unsigned char           preempt_count;
  22         int                     pid;
  23         int                     tgid;
  24 };
  25
  26 /*
  27  * Trace iterator - used by printout routines who present trace
  28  * results to users and which routines might sleep, etc:
  29  */
  30 struct trace_iterator {
  31         struct trace_array      *tr;
  32         struct tracer           *trace;
  33         void                    *private;
  34         int                     cpu_file;
  35         struct mutex            mutex;
  36         struct ring_buffer_iter *buffer_iter[NR_CPUS];
  37
  38         /* The below is zeroed out in pipe_read */
  39         struct trace_seq        seq;
  40         struct trace_entry      *ent;
  41         int                     cpu;
  42         u64                     ts;
  43
  44         unsigned long           iter_flags;
  45         loff_t                  pos;
  46         long                    idx;
  47
  48         cpumask_var_t           started;
  49 };
  50
  51
  52 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  53                                               int flags);
  54 struct trace_event {
  55         struct hlist_node       node;
  56         int                     type;
  57         trace_print_func        trace;
  58         trace_print_func        raw;
  59         trace_print_func        hex;
  60         trace_print_func        binary;
  61 };
  62
  63 extern int register_ftrace_event(struct trace_event *event);
  64 extern int unregister_ftrace_event(struct trace_event *event);
  65
  66 /* Return values for print_line callback */
  67 enum print_line_t {
  68         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
  69         TRACE_TYPE_HANDLED      = 1,
  70         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
  71         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
  72 };
  73
  74
  75 struct ring_buffer_event *
  76 trace_current_buffer_lock_reserve(int type, unsigned long len,
  77                                   unsigned long flags, int pc);
  78 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
  79                                         unsigned long flags, int pc);
  80 void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
  81                                         unsigned long flags, int pc);
  82 void trace_current_buffer_discard_commit(struct ring_buffer_event *event);
  83
  84 void tracing_record_cmdline(struct task_struct *tsk);
  85
  86 struct ftrace_event_call {
  87         struct list_head        list;
  88         char                    *name;
  89         char                    *system;
  90         struct dentry           *dir;
  91         struct trace_event      *event;
  92         int                     enabled;
  93         int                     (*regfunc)(void);
  94         void                    (*unregfunc)(void);
  95         int                     id;
  96         int                     (*raw_init)(void);
  97         int                     (*show_format)(struct trace_seq *s);
  98         int                     (*define_fields)(void);
  99         struct list_head        fields;
 100         int                     n_preds;
 101         struct filter_pred      **preds;
 102         void                    *mod;
 103
 104 #ifdef CONFIG_EVENT_PROFILE
 105         atomic_t        profile_count;
 106         int             (*profile_enable)(struct ftrace_event_call *);
 107         void            (*profile_disable)(struct ftrace_event_call *);
 108 #endif
 109 };
 110
 111 #define MAX_FILTER_PRED         8
 112 #define MAX_FILTER_STR_VAL      128
 113
 114 extern int init_preds(struct ftrace_event_call *call);
 115 extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
 116 extern int filter_current_check_discard(struct ftrace_event_call *call,
 117                                         void *rec,
 118                                         struct ring_buffer_event *event);
 119
 120 extern int trace_define_field(struct ftrace_event_call *call, char *type,
 121                               char *name, int offset, int size);
 122
 123
 124 /*
 125  * The double __builtin_constant_p is because gcc will give us an error
 126  * if we try to allocate the static variable to fmt if it is not a
 127  * constant. Even with the outer if statement optimizing out.
 128  */
 129 #define event_trace_printk(ip, fmt, args...)                            \
 130 do {                                                                    \
 131         __trace_printk_check_format(fmt, ##args);                       \
 132         tracing_record_cmdline(current);                                \
 133         if (__builtin_constant_p(fmt)) {                                \
 134                 static const char *trace_printk_fmt                     \
 135                   __attribute__((section("__trace_printk_fmt"))) =      \
 136                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 137                                                                         \
 138                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 139         } else                                                          \
 140                 __trace_printk(ip, fmt, ##args);                        \
 141 } while (0)
 142
 143 #define __common_field(type, item)                                      \
 144         ret = trace_define_field(event_call, #type, "common_" #item,    \
 145                                  offsetof(typeof(field.ent), item),     \
 146                                  sizeof(field.ent.item));               \
 147         if (ret)                                                        \
 148                 return ret;
 149
 150 #endif /* _LINUX_FTRACE_EVENT_H */