diff options
Diffstat (limited to 'include/linux/tracepoint.h')
-rw-r--r-- | include/linux/tracepoint.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h new file mode 100644 index 00000000000..e623a6fca5c --- /dev/null +++ b/include/linux/tracepoint.h @@ -0,0 +1,127 @@ +#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); + +#endif |