From e9d0d0b01f89750d66f3e324607f6bb1f4db387a Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 26 Feb 2014 13:37:38 -0500 Subject: tracing: Do not add event files for modules that fail tracepoints commit 45ab2813d40d88fc575e753c38478de242d03f88 upstream. If a module fails to add its tracepoints due to module tainting, do not create the module event infrastructure in the debugfs directory. As the events will not work and worse yet, they will silently fail, making the user wonder why the events they enable do not display anything. Having a warning on module load and the events not visible to the users will make the cause of the problem much clearer. Link: http://lkml.kernel.org/r/20140227154923.265882695@goodmis.org Fixes: 6d723736e472 "tracing/events: add support for modules to TRACE_EVENT" Acked-by: Mathieu Desnoyers Cc: Rusty Russell Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings --- kernel/trace/trace_events.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index c212a7f..875fed4 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1345,6 +1345,16 @@ static void trace_module_add_events(struct module *mod) struct ftrace_module_file_ops *file_ops = NULL; struct ftrace_event_call **call, **start, **end; + if (!mod->num_trace_events) + return; + + /* Don't add infrastructure for mods without tracepoints */ + if (trace_module_has_bad_taint(mod)) { + pr_err("%s: module has bad taint, not creating trace events\n", + mod->name); + return; + } + start = mod->trace_events; end = mod->trace_events + mod->num_trace_events; -- cgit v1.1