lockdep/selftest: Add spin_nest_lock test (e04ce676) · Commits · 戴 / test

Add a self test case to test the behavior for the following case: lock(A); lock_nest_lock(C1, A); lock(B); lock_nest_lock(C2, A); This is a reproducer for a problem[1] reported by Chris Wilson, and is helpful to prevent this. [1]: https://lore.kernel.org/lkml/160390684819.31966.12048967113267928793@build.alporthouse.com/ Signed-off-by:

lib/locking-selftest.c

+17 −0

Original line number	Diff line number	Diff line
		@@ -2009,6 +2009,19 @@ static void ww_test_spin_nest_unlocked(void)
		U(A);
		}

		/* This is not a deadlock, because we have X1 to serialize Y1 and Y2 */
		static void ww_test_spin_nest_lock(void)
		{
		spin_lock(&lock_X1);
		spin_lock_nest_lock(&lock_Y1, &lock_X1);
		spin_lock(&lock_A);
		spin_lock_nest_lock(&lock_Y2, &lock_X1);
		spin_unlock(&lock_A);
		spin_unlock(&lock_Y2);
		spin_unlock(&lock_Y1);
		spin_unlock(&lock_X1);
		}

		static void ww_test_unneeded_slow(void)
		{
		WWAI(&t);
		@@ -2226,6 +2239,10 @@ static void ww_tests(void)
		dotest(ww_test_spin_nest_unlocked, FAILURE, LOCKTYPE_WW);
		pr_cont("\n");

		print_testname("spinlock nest test");
		dotest(ww_test_spin_nest_lock, SUCCESS, LOCKTYPE_WW);
		pr_cont("\n");

		printk(" -----------------------------------------------------\n");
		printk(" \|block \| try \|context\|\n");
		printk(" -----------------------------------------------------\n");