#ifndef _LINUX_TRACEPOINT_H
#define _LINUX_TRACEPOINT_H
/*
* Kernel Tracepoint API.
*
* See Documentation/tracepoint.txt.
*
* (C) Copyright 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
*
* Heavily inspired from the Linux Kernel Markers.
*
* This file is released under the GPLv2.
* See the file COPYING for more details.
*/
#include <linux/types.h>
#include <linux/rcupdate.h>
struct module;
struct tracepoint;
struct tracepoint {
const char *name; /* Tracepoint name */
int state; /* State. */
void **funcs;
} __attribute__((aligned(8)));
#define TPPROTO(args...) args
#define TPARGS(args...) args
#ifdef CONFIG_TRACEPOINTS
/*
* it_func[0] is never NULL because there is at least one element in the array
* when the array itself is non NULL.
*/
#define __DO_TRACE(tp, proto, args) \
do { \
void **it_func; \
\
rcu_read_lock_sched(); \
it_func = rcu_dereference((tp)->funcs); \
if (it_func) { \
do { \
((void(*)(proto))(*it_func))(args); \
} while (*(++it_func)); \
} \
rcu_read_unlock_sched(); \
} while (0)
/*
* Make sure the alignment of the structure in the __tracepoints section will
* not add unwanted padding between the beginning of the section and the
* structure. Force alignment to the same alignment as the section start.
*/
#define DEFINE_TRACE(name, proto, args) \
static inline void trace_##name(proto) \
{ \
static const char __tpstrtab_##name[] \
__attribute__((section("__tracepoints_strings"))) \
= #name ":" #proto; \
static struct tracepoint __tracepoint_##name \
__attribute__((section("__tracepoints"), aligned(8))) = \
{ __tpstrtab_##name, 0, NULL }; \
if (unlikely(__tracepoint_##name.state)) \
__DO_TRACE(&__tracepoint_##name, \
TPPROTO(proto), TPARGS(args)); \
} \
static inline int register_trace_##name(void (*probe)(proto)) \
{ \
return tracepoint_probe_register(#name ":" #proto, \
(void *)probe); \
} \
static inline void unregister_trace_##name(void (*probe)(proto))\
{ \
tracepoint_probe_unregister(#name ":" #proto, \
(void *)probe); \
}
extern void tracepoint_update_probe_range(struct tracepoint *begin,
struct tracepoint *end);
#else /* !CONFIG_TRACEPOINTS */
#define DEFINE_TRACE(name, proto, args) \
static inline void _do_trace_##name(struct tracepoint *tp, proto) \
{ } \
static inline void trace_##name(proto) \
{ } \
static inline int register_trace_##name(void (*probe)(proto)) \
{ \
return -ENOSYS; \
} \
static inline void unregister_trace_##name(void (*probe)(proto))\
{ }
static inline void tracepoint_update_probe_range(struct tracepoint *begin,
struct tracepoint *end)
{ }
#endif /* CONFIG_TRACEPOINTS */
/*
* Connect a probe to a tracepoint.
* Internal API, should not be used directly.
*/
extern int tracepoint_probe_register(const char *name, void *probe);
/*
* Disconnect a probe from a tracepoint.
* Internal API, should not be used directly.
*/
extern int tracepoint_probe_unregister(const char *name, void *probe);
struct tracepoint_iter {
struct module *module;
struct tracepoint *tracepoint;
};
extern void tracepoint_iter_start(struct tracepoint_iter *iter);
extern void tracepoint_iter_next(struct tracepoint_iter *iter);
extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
extern int tracepoint_get_iter_range(struct tracepoint **tracepoint,
struct tracepoint *begin, struct tracepoint *end);
/*
* tracepoint_synchronize_unregister must be called between the last tracepoint
* probe unregistration and the end of module exit to make sure there is no
* caller executing a probe when it is freed.
*/
static inline void tracepoint_synchronize_unregister(void)
{
synchronize_sched();
}
#endif
