tracepoints: API doc update to tracepoint_probe_register() return value
Describe the return values of tracepoint_probe_register(), including
-ENODEV added by commit:
Author: Steven Rostedt <rostedt@goodmis.org>
tracing: Warn if a tracepoint is not set via debugfs
Link: http://lkml.kernel.org/r/1394499898-1537-2-git-send-email-mathieu.desnoyers@efficios.com
CC: Ingo Molnar <mingo@kernel.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index a4f629d..e2a58a2 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -378,7 +378,17 @@
* @probe: probe handler
* @data: probe private data
*
- * Returns 0 if ok, error value on error.
+ * Returns:
+ * - 0 if the probe was successfully registered, and tracepoint
+ * callsites are currently loaded for that probe,
+ * - -ENODEV if the probe was successfully registered, but no tracepoint
+ * callsite is currently loaded for that probe,
+ * - other negative error value on error.
+ *
+ * When tracepoint_probe_register() returns either 0 or -ENODEV,
+ * parameters @name, @probe, and @data may be used by the tracepoint
+ * infrastructure until the probe is unregistered.
+ *
* The probe address must at least be aligned on the architecture pointer size.
*/
int tracepoint_probe_register(const char *name, void *probe, void *data)