tracing: Postpone tracer start-up tests till the system is more robust (9afecfbb) · Commits · 戴 / test

kernel/trace/trace.c

+71 −0

Original line number	Diff line number	Diff line
		@@ -1424,6 +1424,28 @@ static int wait_on_pipe(struct trace_iterator *iter, bool full)
		}

		#ifdef CONFIG_FTRACE_STARTUP_TEST
		static bool selftests_can_run;

		struct trace_selftests {
		struct list_head list;
		struct tracer *type;
		};

		static LIST_HEAD(postponed_selftests);

		static int save_selftest(struct tracer *type)
		{
		struct trace_selftests *selftest;

		selftest = kmalloc(sizeof(*selftest), GFP_KERNEL);
		if (!selftest)
		return -ENOMEM;

		selftest->type = type;
		list_add(&selftest->list, &postponed_selftests);
		return 0;
		}

		static int run_tracer_selftest(struct tracer *type)
		{
		struct trace_array *tr = &global_trace;
		@@ -1433,6 +1455,14 @@ static int run_tracer_selftest(struct tracer *type)
		if (!type->selftest \|\| tracing_selftest_disabled)
		return 0;

		/*
		* If a tracer registers early in boot up (before scheduling is
		* initialized and such), then do not run its selftests yet.
		* Instead, run it a little later in the boot process.
		*/
		if (!selftests_can_run)
		return save_selftest(type);

		/*
		* Run a selftest on this tracer.
		* Here we reset the trace buffer, and set the current
		@@ -1482,6 +1512,47 @@ static int run_tracer_selftest(struct tracer *type)
		printk(KERN_CONT "PASSED\n");
		return 0;
		}

		static __init int init_trace_selftests(void)
		{
		struct trace_selftests p, n;
		struct tracer t, *last;
		int ret;

		selftests_can_run = true;

		mutex_lock(&trace_types_lock);

		if (list_empty(&postponed_selftests))
		goto out;

		pr_info("Running postponed tracer tests:\n");

		list_for_each_entry_safe(p, n, &postponed_selftests, list) {
		ret = run_tracer_selftest(p->type);
		/* If the test fails, then warn and remove from available_tracers */
		if (ret < 0) {
		WARN(1, "tracer: %s failed selftest, disabling\n",
		p->type->name);
		last = &trace_types;
		for (t = trace_types; t; t = t->next) {
		if (t == p->type) {
		*last = t->next;
		break;
		}
		last = &t->next;
		}
		}
		list_del(&p->list);
		kfree(p);
		}

		out:
		mutex_unlock(&trace_types_lock);

		return 0;
		}
		early_initcall(init_trace_selftests);
		#else
		static inline int run_tracer_selftest(struct tracer *type)
		{

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