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97e1c18e MD |
1 | #ifndef _LINUX_TRACEPOINT_H |
2 | #define _LINUX_TRACEPOINT_H | |
3 | ||
4 | /* | |
5 | * Kernel Tracepoint API. | |
6 | * | |
7 | * See Documentation/tracepoint.txt. | |
8 | * | |
9 | * (C) Copyright 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | |
10 | * | |
11 | * Heavily inspired from the Linux Kernel Markers. | |
12 | * | |
13 | * This file is released under the GPLv2. | |
14 | * See the file COPYING for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/types.h> | |
18 | #include <linux/rcupdate.h> | |
19 | ||
20 | struct module; | |
21 | struct tracepoint; | |
22 | ||
23 | struct tracepoint { | |
24 | const char *name; /* Tracepoint name */ | |
25 | int state; /* State. */ | |
26 | void **funcs; | |
7e066fb8 MD |
27 | } __attribute__((aligned(32))); /* |
28 | * Aligned on 32 bytes because it is | |
29 | * globally visible and gcc happily | |
30 | * align these on the structure size. | |
31 | * Keep in sync with vmlinux.lds.h. | |
32 | */ | |
97e1c18e MD |
33 | |
34 | #define TPPROTO(args...) args | |
35 | #define TPARGS(args...) args | |
36 | ||
37 | #ifdef CONFIG_TRACEPOINTS | |
38 | ||
39 | /* | |
40 | * it_func[0] is never NULL because there is at least one element in the array | |
41 | * when the array itself is non NULL. | |
42 | */ | |
43 | #define __DO_TRACE(tp, proto, args) \ | |
44 | do { \ | |
45 | void **it_func; \ | |
46 | \ | |
da7b3eab | 47 | rcu_read_lock_sched_notrace(); \ |
97e1c18e MD |
48 | it_func = rcu_dereference((tp)->funcs); \ |
49 | if (it_func) { \ | |
50 | do { \ | |
51 | ((void(*)(proto))(*it_func))(args); \ | |
52 | } while (*(++it_func)); \ | |
53 | } \ | |
da7b3eab | 54 | rcu_read_unlock_sched_notrace(); \ |
97e1c18e MD |
55 | } while (0) |
56 | ||
57 | /* | |
58 | * Make sure the alignment of the structure in the __tracepoints section will | |
59 | * not add unwanted padding between the beginning of the section and the | |
60 | * structure. Force alignment to the same alignment as the section start. | |
61 | */ | |
7e066fb8 MD |
62 | #define DECLARE_TRACE(name, proto, args) \ |
63 | extern struct tracepoint __tracepoint_##name; \ | |
97e1c18e MD |
64 | static inline void trace_##name(proto) \ |
65 | { \ | |
97e1c18e MD |
66 | if (unlikely(__tracepoint_##name.state)) \ |
67 | __DO_TRACE(&__tracepoint_##name, \ | |
68 | TPPROTO(proto), TPARGS(args)); \ | |
69 | } \ | |
70 | static inline int register_trace_##name(void (*probe)(proto)) \ | |
71 | { \ | |
5f382671 | 72 | return tracepoint_probe_register(#name, (void *)probe); \ |
97e1c18e | 73 | } \ |
c420970e | 74 | static inline int unregister_trace_##name(void (*probe)(proto)) \ |
97e1c18e | 75 | { \ |
5f382671 | 76 | return tracepoint_probe_unregister(#name, (void *)probe);\ |
97e1c18e MD |
77 | } |
78 | ||
7e066fb8 MD |
79 | #define DEFINE_TRACE(name) \ |
80 | static const char __tpstrtab_##name[] \ | |
81 | __attribute__((section("__tracepoints_strings"))) = #name; \ | |
82 | struct tracepoint __tracepoint_##name \ | |
83 | __attribute__((section("__tracepoints"), aligned(32))) = \ | |
84 | { __tpstrtab_##name, 0, NULL } | |
85 | ||
86 | #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \ | |
87 | EXPORT_SYMBOL_GPL(__tracepoint_##name) | |
88 | #define EXPORT_TRACEPOINT_SYMBOL(name) \ | |
89 | EXPORT_SYMBOL(__tracepoint_##name) | |
90 | ||
97e1c18e MD |
91 | extern void tracepoint_update_probe_range(struct tracepoint *begin, |
92 | struct tracepoint *end); | |
93 | ||
94 | #else /* !CONFIG_TRACEPOINTS */ | |
7e066fb8 | 95 | #define DECLARE_TRACE(name, proto, args) \ |
97e1c18e MD |
96 | static inline void _do_trace_##name(struct tracepoint *tp, proto) \ |
97 | { } \ | |
98 | static inline void trace_##name(proto) \ | |
99 | { } \ | |
100 | static inline int register_trace_##name(void (*probe)(proto)) \ | |
101 | { \ | |
102 | return -ENOSYS; \ | |
103 | } \ | |
c420970e MD |
104 | static inline int unregister_trace_##name(void (*probe)(proto)) \ |
105 | { \ | |
106 | return -ENOSYS; \ | |
107 | } | |
97e1c18e | 108 | |
7e066fb8 MD |
109 | #define DEFINE_TRACE(name) |
110 | #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) | |
111 | #define EXPORT_TRACEPOINT_SYMBOL(name) | |
112 | ||
97e1c18e MD |
113 | static inline void tracepoint_update_probe_range(struct tracepoint *begin, |
114 | struct tracepoint *end) | |
115 | { } | |
116 | #endif /* CONFIG_TRACEPOINTS */ | |
117 | ||
118 | /* | |
119 | * Connect a probe to a tracepoint. | |
120 | * Internal API, should not be used directly. | |
121 | */ | |
122 | extern int tracepoint_probe_register(const char *name, void *probe); | |
123 | ||
124 | /* | |
125 | * Disconnect a probe from a tracepoint. | |
126 | * Internal API, should not be used directly. | |
127 | */ | |
128 | extern int tracepoint_probe_unregister(const char *name, void *probe); | |
129 | ||
127cafbb LJ |
130 | extern int tracepoint_probe_register_noupdate(const char *name, void *probe); |
131 | extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe); | |
132 | extern void tracepoint_probe_update_all(void); | |
133 | ||
97e1c18e MD |
134 | struct tracepoint_iter { |
135 | struct module *module; | |
136 | struct tracepoint *tracepoint; | |
137 | }; | |
138 | ||
139 | extern void tracepoint_iter_start(struct tracepoint_iter *iter); | |
140 | extern void tracepoint_iter_next(struct tracepoint_iter *iter); | |
141 | extern void tracepoint_iter_stop(struct tracepoint_iter *iter); | |
142 | extern void tracepoint_iter_reset(struct tracepoint_iter *iter); | |
143 | extern int tracepoint_get_iter_range(struct tracepoint **tracepoint, | |
144 | struct tracepoint *begin, struct tracepoint *end); | |
145 | ||
f2461fc8 MD |
146 | /* |
147 | * tracepoint_synchronize_unregister must be called between the last tracepoint | |
148 | * probe unregistration and the end of module exit to make sure there is no | |
149 | * caller executing a probe when it is freed. | |
150 | */ | |
231375cc MD |
151 | static inline void tracepoint_synchronize_unregister(void) |
152 | { | |
153 | synchronize_sched(); | |
154 | } | |
f2461fc8 | 155 | |
97e1c18e | 156 | #endif |