tracing: Fix traceoff_on_warning handling on boot command line

According to the documentation, adding "traceoff_on_warning" to the boot
command line should be enough to enable the feature. But right now it is
necessary to specify "traceoff_on_warning=". Along with fixing that, also
verify if the value passed, if any, is either "0" or "off".

Link: http://lkml.kernel.org/r/20141112231400.GL12281@uudg.org
Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8a528392b1f465da19d297a84699c4931102cf3d..75798ab8eb88a6b85df209f127d9a7014f95ccca 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -155,10 +155,11 @@ __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
 
 static int __init stop_trace_on_warning(char *str)
 {
-       __disable_trace_on_warning = 1;
+       if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0))
+               __disable_trace_on_warning = 1;
        return 1;
 }
-__setup("traceoff_on_warning=", stop_trace_on_warning);
+__setup("traceoff_on_warning", stop_trace_on_warning);
 
 static int __init boot_alloc_snapshot(char *str)
 {