1 #ifndef _LINUX_TRACEPOINT_H
2 #define _LINUX_TRACEPOINT_H
5 * Kernel Tracepoint API.
7 * See Documentation/tracepoint.txt.
9 * (C) Copyright 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
11 * Heavily inspired from the Linux Kernel Markers.
13 * This file is released under the GPLv2.
14 * See the file COPYING for more details.
17 #include <linux/types.h>
18 #include <linux/rcupdate.h>
24 const char *name; /* Tracepoint name */
25 int state; /* State. */
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.
34 #define TPPROTO(args...) args
35 #define TPARGS(args...) args
37 #ifdef CONFIG_TRACEPOINTS
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.
43 #define __DO_TRACE(tp, proto, args) \
47 rcu_read_lock_sched_notrace(); \
48 it_func = rcu_dereference((tp)->funcs); \
51 ((void(*)(proto))(*it_func))(args); \
52 } while (*(++it_func)); \
54 rcu_read_unlock_sched_notrace(); \
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.
62 #define DECLARE_TRACE(name, proto, args) \
63 extern struct tracepoint __tracepoint_##name; \
64 static inline void trace_##name(proto) \
66 if (unlikely(__tracepoint_##name.state)) \
67 __DO_TRACE(&__tracepoint_##name, \
68 TPPROTO(proto), TPARGS(args)); \
70 static inline int register_trace_##name(void (*probe)(proto)) \
72 return tracepoint_probe_register(#name, (void *)probe); \
74 static inline int unregister_trace_##name(void (*probe)(proto)) \
76 return tracepoint_probe_unregister(#name, (void *)probe);\
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 }
86 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
87 EXPORT_SYMBOL_GPL(__tracepoint_##name)
88 #define EXPORT_TRACEPOINT_SYMBOL(name) \
89 EXPORT_SYMBOL(__tracepoint_##name)
91 extern void tracepoint_update_probe_range(struct tracepoint *begin,
92 struct tracepoint *end);
94 #else /* !CONFIG_TRACEPOINTS */
95 #define DECLARE_TRACE(name, proto, args) \
96 static inline void _do_trace_##name(struct tracepoint *tp, proto) \
98 static inline void trace_##name(proto) \
100 static inline int register_trace_##name(void (*probe)(proto)) \
104 static inline int unregister_trace_##name(void (*probe)(proto)) \
109 #define DEFINE_TRACE(name)
110 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
111 #define EXPORT_TRACEPOINT_SYMBOL(name)
113 static inline void tracepoint_update_probe_range(struct tracepoint *begin,
114 struct tracepoint *end)
116 #endif /* CONFIG_TRACEPOINTS */
119 * Connect a probe to a tracepoint.
120 * Internal API, should not be used directly.
122 extern int tracepoint_probe_register(const char *name, void *probe);
125 * Disconnect a probe from a tracepoint.
126 * Internal API, should not be used directly.
128 extern int tracepoint_probe_unregister(const char *name, void *probe);
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);
134 struct tracepoint_iter {
135 struct module *module;
136 struct tracepoint *tracepoint;
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);
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.
151 static inline void tracepoint_synchronize_unregister(void)