kcsan: Add atomic builtin test case (f9ea6319) · Commits · 戴 / test

kernel/kcsan/kcsan-test.c

+63 −0

Original line number	Diff line number	Diff line
		@@ -390,6 +390,15 @@ static noinline void test_kernel_seqlock_writer(void)
		write_sequnlock_irqrestore(&test_seqlock, flags);
		}

		static noinline void test_kernel_atomic_builtins(void)
		{
		/*
		* Generate concurrent accesses, expecting no reports, ensuring KCSAN
		* treats builtin atomics as actually atomic.
		*/
		__atomic_load_n(&test_var, __ATOMIC_RELAXED);
		}

		/* ===== Test cases ===== */

		/* Simple test with normal data race. */
		@@ -852,6 +861,59 @@ static void test_seqlock_noreport(struct kunit *test)
		KUNIT_EXPECT_FALSE(test, match_never);
		}

		/*
		* Test atomic builtins work and required instrumentation functions exist. We
		* also test that KCSAN understands they're atomic by racing with them via
		* test_kernel_atomic_builtins(), and expect no reports.
		*
		* The atomic builtins _SHOULD NOT_ be used in normal kernel code!
		*/
		static void test_atomic_builtins(struct kunit *test)
		{
		bool match_never = false;

		begin_test_checks(test_kernel_atomic_builtins, test_kernel_atomic_builtins);
		do {
		long tmp;

		kcsan_enable_current();

		__atomic_store_n(&test_var, 42L, __ATOMIC_RELAXED);
		KUNIT_EXPECT_EQ(test, 42L, __atomic_load_n(&test_var, __ATOMIC_RELAXED));

		KUNIT_EXPECT_EQ(test, 42L, __atomic_exchange_n(&test_var, 20, __ATOMIC_RELAXED));
		KUNIT_EXPECT_EQ(test, 20L, test_var);

		tmp = 20L;
		KUNIT_EXPECT_TRUE(test, __atomic_compare_exchange_n(&test_var, &tmp, 30L,
		0, __ATOMIC_RELAXED,
		__ATOMIC_RELAXED));
		KUNIT_EXPECT_EQ(test, tmp, 20L);
		KUNIT_EXPECT_EQ(test, test_var, 30L);
		KUNIT_EXPECT_FALSE(test, __atomic_compare_exchange_n(&test_var, &tmp, 40L,
		1, __ATOMIC_RELAXED,
		__ATOMIC_RELAXED));
		KUNIT_EXPECT_EQ(test, tmp, 30L);
		KUNIT_EXPECT_EQ(test, test_var, 30L);

		KUNIT_EXPECT_EQ(test, 30L, __atomic_fetch_add(&test_var, 1, __ATOMIC_RELAXED));
		KUNIT_EXPECT_EQ(test, 31L, __atomic_fetch_sub(&test_var, 1, __ATOMIC_RELAXED));
		KUNIT_EXPECT_EQ(test, 30L, __atomic_fetch_and(&test_var, 0xf, __ATOMIC_RELAXED));
		KUNIT_EXPECT_EQ(test, 14L, __atomic_fetch_xor(&test_var, 0xf, __ATOMIC_RELAXED));
		KUNIT_EXPECT_EQ(test, 1L, __atomic_fetch_or(&test_var, 0xf0, __ATOMIC_RELAXED));
		KUNIT_EXPECT_EQ(test, 241L, __atomic_fetch_nand(&test_var, 0xf, __ATOMIC_RELAXED));
		KUNIT_EXPECT_EQ(test, -2L, test_var);

		__atomic_thread_fence(__ATOMIC_SEQ_CST);
		__atomic_signal_fence(__ATOMIC_SEQ_CST);

		kcsan_disable_current();

		match_never = report_available();
		} while (!end_test_checks(match_never));
		KUNIT_EXPECT_FALSE(test, match_never);
		}

		/*
		* Each test case is run with different numbers of threads. Until KUnit supports
		* passing arguments for each test case, we encode #threads in the test case
		@@ -891,6 +953,7 @@ static struct kunit_case kcsan_test_cases[] = {
		KCSAN_KUNIT_CASE(test_assert_exclusive_access_scoped),
		KCSAN_KUNIT_CASE(test_jiffies_noreport),
		KCSAN_KUNIT_CASE(test_seqlock_noreport),
		KCSAN_KUNIT_CASE(test_atomic_builtins),
		{},
		};

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