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         unsigned short          type;
  20         unsigned char           flags;
  21         unsigned char           preempt_count;
  22         int                     pid;
  23         int                     tgid;
  24 };
  25
  26 #define FTRACE_MAX_EVENT                                                \
  27         ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  28
  29 /*
  30  * Trace iterator - used by printout routines who present trace
  31  * results to users and which routines might sleep, etc:
  32  */
  33 struct trace_iterator {
  34         struct trace_array      *tr;
  35         struct tracer           *trace;
  36         void                    *private;
  37         int                     cpu_file;
  38         struct mutex            mutex;
  39         struct ring_buffer_iter *buffer_iter[NR_CPUS];
  40
  41         /* The below is zeroed out in pipe_read */
  42         struct trace_seq        seq;
  43         struct trace_entry      *ent;
  44         int                     cpu;
  45         u64                     ts;
  46
  47         unsigned long           iter_flags;
  48         loff_t                  pos;
  49         long                    idx;
  50
  51         cpumask_var_t           started;
  52 };
  53
  54
  55 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
  56                                               int flags);
  57 struct trace_event {
  58         struct hlist_node       node;
  59         struct list_head        list;
  60         int                     type;
  61         trace_print_func        trace;
  62         trace_print_func        raw;
  63         trace_print_func        hex;
  64         trace_print_func        binary;
  65 };
  66
  67 extern int register_ftrace_event(struct trace_event *event);
  68 extern int unregister_ftrace_event(struct trace_event *event);
  69
  70 /* Return values for print_line callback */
  71 enum print_line_t {
  72         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
  73         TRACE_TYPE_HANDLED      = 1,
  74         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
  75         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
  76 };
  77
  78
  79 struct ring_buffer_event *
  80 trace_current_buffer_lock_reserve(int type, unsigned long len,
  81                                   unsigned long flags, int pc);
  82 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
  83                                         unsigned long flags, int pc);
  84 void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
  85                                         unsigned long flags, int pc);
  86 void trace_current_buffer_discard_commit(struct ring_buffer_event *event);
  87
  88 void tracing_record_cmdline(struct task_struct *tsk);
  89
  90 struct ftrace_event_call {
  91         struct list_head        list;
  92         char                    *name;
  93         char                    *system;
  94         struct dentry           *dir;
  95         struct trace_event      *event;
  96         int                     enabled;
  97         int                     (*regfunc)(void);
  98         void                    (*unregfunc)(void);
  99         int                     id;
 100         int                     (*raw_init)(void);
 101         int                     (*show_format)(struct trace_seq *s);
 102         int                     (*define_fields)(void);
 103         struct list_head        fields;
 104         int                     filter_active;
 105         void                    *filter;
 106         void                    *mod;
 107
 108 #ifdef CONFIG_EVENT_PROFILE
 109         atomic_t        profile_count;
 110         int             (*profile_enable)(struct ftrace_event_call *);
 111         void            (*profile_disable)(struct ftrace_event_call *);
 112 #endif
 113 };
 114
 115 #define MAX_FILTER_PRED         32
 116 #define MAX_FILTER_STR_VAL      128
 117
 118 extern int init_preds(struct ftrace_event_call *call);
 119 extern void destroy_preds(struct ftrace_event_call *call);
 120 extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
 121 extern int filter_current_check_discard(struct ftrace_event_call *call,
 122                                         void *rec,
 123                                         struct ring_buffer_event *event);
 124
 125 extern int trace_define_field(struct ftrace_event_call *call, char *type,
 126                               char *name, int offset, int size, int is_signed);
 127
 128 #define is_signed_type(type)    (((type)(-1)) < 0)
 129
 130 /*
 131  * The double __builtin_constant_p is because gcc will give us an error
 132  * if we try to allocate the static variable to fmt if it is not a
 133  * constant. Even with the outer if statement optimizing out.
 134  */
 135 #define event_trace_printk(ip, fmt, args...)                            \
 136 do {                                                                    \
 137         __trace_printk_check_format(fmt, ##args);                       \
 138         tracing_record_cmdline(current);                                \
 139         if (__builtin_constant_p(fmt)) {                                \
 140                 static const char *trace_printk_fmt                     \
 141                   __attribute__((section("__trace_printk_fmt"))) =      \
 142                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 143                                                                         \
 144                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 145         } else                                                          \
 146                 __trace_printk(ip, fmt, ##args);                        \
 147 } while (0)
 148
 149 #define __common_field(type, item, is_signed)                           \
 150         ret = trace_define_field(event_call, #type, "common_" #item,    \
 151                                  offsetof(typeof(field.ent), item),     \
 152                                  sizeof(field.ent.item), is_signed);    \
 153         if (ret)                                                        \
 154                 return ret;
 155
 156 #endif /* _LINUX_FTRACE_EVENT_H */