tracing/filters: a better event parser
[safe/jmp/linux-2.6] / 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 int filter_match_preds(struct ftrace_event_call *call, void *rec);
120 extern int filter_current_check_discard(struct ftrace_event_call *call,
121                                         void *rec,
122                                         struct ring_buffer_event *event);
123
124 extern int trace_define_field(struct ftrace_event_call *call, char *type,
125                               char *name, int offset, int size, int is_signed);
126
127 #define is_signed_type(type)    (((type)(-1)) < 0)
128
129 /*
130  * The double __builtin_constant_p is because gcc will give us an error
131  * if we try to allocate the static variable to fmt if it is not a
132  * constant. Even with the outer if statement optimizing out.
133  */
134 #define event_trace_printk(ip, fmt, args...)                            \
135 do {                                                                    \
136         __trace_printk_check_format(fmt, ##args);                       \
137         tracing_record_cmdline(current);                                \
138         if (__builtin_constant_p(fmt)) {                                \
139                 static const char *trace_printk_fmt                     \
140                   __attribute__((section("__trace_printk_fmt"))) =      \
141                         __builtin_constant_p(fmt) ? fmt : NULL;         \
142                                                                         \
143                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
144         } else                                                          \
145                 __trace_printk(ip, fmt, ##args);                        \
146 } while (0)
147
148 #define __common_field(type, item, is_signed)                           \
149         ret = trace_define_field(event_call, #type, "common_" #item,    \
150                                  offsetof(typeof(field.ent), item),     \
151                                  sizeof(field.ent.item), is_signed);    \
152         if (ret)                                                        \
153                 return ret;
154
155 #endif /* _LINUX_FTRACE_EVENT_H */