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-rw-r--r--include/linux/tracepoint.h137
1 files changed, 137 insertions, 0 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
new file mode 100644
index 000000000000..c5bb39c7a770
--- /dev/null
+++ b/include/linux/tracepoint.h
@@ -0,0 +1,137 @@
+#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