Messages in this thread | | | From | Alexander Lam <> | Date | Mon, 1 Jul 2013 19:21:14 -0700 | Subject | Re: [PATCH 3/3] tracing: Protect ftrace_trace_arrays list in trace_events.c |
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Oh, sorry, that is an incomplete patch; some bits are in a patch I dropped. I'll send you a new one in about 20 minutes.
- Alex
On Mon, Jul 1, 2013 at 6:25 PM, Steven Rostedt <rostedt@goodmis.org> wrote: > On Mon, 2013-07-01 at 15:31 -0700, Alexander Z Lam wrote: >> There are multiple places where the ftrace_trace_arrays list is accessed in >> trace_events.c without the trace_types_lock held. > > Hmm, doesn't compile. Not a complete patch? trace_types_lock is local to > trace.c, and needs to be in trace.h and non static. > > -- Steve > >> >> Cc: David Sharp <dhsharp@google.com> >> Cc: Alexander Z Lam <lambchop468@gmail.com> >> Signed-off-by: Alexander Z Lam <azl@google.com> >> --- >> kernel/trace/trace_events.c | 9 ++++++++- >> 1 file changed, 8 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c >> index 6db3290..26351cc 100644 >> --- a/kernel/trace/trace_events.c >> +++ b/kernel/trace/trace_events.c >> @@ -1586,6 +1586,7 @@ static void __add_event_to_tracers(struct ftrace_event_call *call, >> int trace_add_event_call(struct ftrace_event_call *call) >> { >> int ret; >> + mutex_lock(&trace_types_lock); >> mutex_lock(&event_mutex); >> >> ret = __register_event(call, NULL); >> @@ -1593,11 +1594,13 @@ int trace_add_event_call(struct ftrace_event_call *call) >> __add_event_to_tracers(call, NULL); >> >> mutex_unlock(&event_mutex); >> + mutex_unlock(&trace_types_lock); >> return ret; >> } >> >> /* >> - * Must be called under locking both of event_mutex and trace_event_sem. >> + * Must be called under locking of trace_types_lock, event_mutex and >> + * trace_event_sem. >> */ >> static void __trace_remove_event_call(struct ftrace_event_call *call) >> { >> @@ -1609,11 +1612,13 @@ static void __trace_remove_event_call(struct ftrace_event_call *call) >> /* Remove an event_call */ >> void trace_remove_event_call(struct ftrace_event_call *call) >> { >> + mutex_lock(&trace_types_lock); >> mutex_lock(&event_mutex); >> down_write(&trace_event_sem); >> __trace_remove_event_call(call); >> up_write(&trace_event_sem); >> mutex_unlock(&event_mutex); >> + mutex_unlock(&trace_types_lock); >> } >> >> #define for_each_event(event, start, end) \ >> @@ -1757,6 +1762,7 @@ static int trace_module_notify(struct notifier_block *self, >> { >> struct module *mod = data; >> >> + mutex_lock(&trace_types_lock); >> mutex_lock(&event_mutex); >> switch (val) { >> case MODULE_STATE_COMING: >> @@ -1767,6 +1773,7 @@ static int trace_module_notify(struct notifier_block *self, >> break; >> } >> mutex_unlock(&event_mutex); >> + mutex_unlock(&trace_types_lock); >> >> return 0; >> } > >
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