tracing: Verify if trace array exists before destroying it. (e585e646) · Commits · 戴 / test

kernel/module.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -3728,7 +3728,6 @@ static int complete_formation(struct module mod, struct load_info info)

		module_enable_ro(mod, false);
		module_enable_nx(mod);
		module_enable_x(mod);

		/* Mark state as coming so strong_try_module_get() ignores us,
		* but kallsyms etc. can see us. */
		@@ -3751,6 +3750,11 @@ static int prepare_coming_module(struct module *mod)
		if (err)
		return err;

		/* Make module executable after ftrace is enabled */
		mutex_lock(&module_mutex);
		module_enable_x(mod);
		mutex_unlock(&module_mutex);

		blocking_notifier_call_chain(&module_notify_list,
		MODULE_STATE_COMING, mod);
		return 0;

+12 −3

Original line number	Diff line number	Diff line
		@@ -8556,17 +8556,26 @@ static int __remove_instance(struct trace_array *tr)
		return 0;
		}

		int trace_array_destroy(struct trace_array *tr)
		int trace_array_destroy(struct trace_array *this_tr)
		{
		struct trace_array *tr;
		int ret;

		if (!tr)
		if (!this_tr)
		return -EINVAL;

		mutex_lock(&event_mutex);
		mutex_lock(&trace_types_lock);

		ret = -ENODEV;

		/* Making sure trace array exists before destroying it. */
		list_for_each_entry(tr, &ftrace_trace_arrays, list) {
		if (tr == this_tr) {
		ret = __remove_instance(tr);
		break;
		}
		}

		mutex_unlock(&trace_types_lock);
		mutex_unlock(&event_mutex);