tracing/ftrace: change the type of the init() callback
Impact: extend the ->init() method with the ability to fail
This bring a way to know if the initialization of a tracer successed.
A tracer must return 0 on success and a traditional error (ie:
-ENOMEM) if it fails.
If a tracer fails to init, it is free to print a detailed warn. The
tracing api will not and switch to a new tracer will just return the
error from the init callback.
Note: this will be used for the return tracer.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 8693b7a..e74f6d0 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -42,9 +42,10 @@
tracing_stop_cmdline_record();
}
-static void function_trace_init(struct trace_array *tr)
+static int function_trace_init(struct trace_array *tr)
{
start_function_trace(tr);
+ return 0;
}
static void function_trace_reset(struct trace_array *tr)