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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2014-02-26 18:37:38 (GMT)
committerSteven Rostedt <rostedt@goodmis.org>2014-03-04 02:11:05 (GMT)
commit45ab2813d40d88fc575e753c38478de242d03f88 (patch)
tree1859b05c3be128fd1c0a97c09c2fade4ad91e2e2 /kernel/trace
parent0414855fdc4a40da05221fc6062cccbc0c30f169 (diff)
downloadlinux-45ab2813d40d88fc575e753c38478de242d03f88.tar.xz
tracing: Do not add event files for modules that fail tracepoints
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 <mathieu.desnoyers@efficios.com> Cc: stable@vger.kernel.org # 2.6.31+ Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace_events.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index e71ffd4..f3989ce 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1777,6 +1777,16 @@ static void trace_module_add_events(struct module *mod)
{
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;