Merge tag 'hardening-v6.9-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull more hardening updates from Kees Cook:

 - CONFIG_MEMCPY_SLOW_KUNIT_TEST is no longer needed (Guenter Roeck)

 - Fix needless UTF-8 character in arch/Kconfig (Liu Song)

 - Improve __counted_by warning message in LKDTM (Nathan Chancellor)

 - Refactor DEFINE_FLEX() for default use of __counted_by

 - Disable signed integer overflow sanitizer on GCC < 8

* tag 'hardening-v6.9-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lkdtm/bugs: Improve warning message for compilers without counted_by support
  overflow: Change DEFINE_FLEX to take __counted_by member
  Revert "kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST"
  arch/Kconfig: eliminate needless UTF-8 character in Kconfig help
  ubsan: Disable signed integer overflow sanitizer on GCC < 8

4 files changed, 21 insertions, 15 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index f4a12980a8da..c63a5fbf1f1c 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2703,18 +2703,6 @@ config MEMCPY_KUNIT_TEST
 
 	  If unsure, say N.
 
-config MEMCPY_SLOW_KUNIT_TEST
-	bool "Include exhaustive memcpy tests"
-	depends on MEMCPY_KUNIT_TEST
-	default y
-	help
-	  Some memcpy tests are quite exhaustive in checking for overlaps
-	  and bit ranges. These can be very slow, so they are split out
-	  as a separate config, in case they need to be disabled.
-
-	  Note this config option will be replaced by the use of KUnit test
-	  attributes.
-
 config IS_SIGNED_TYPE_KUNIT_TEST
 	tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
 	depends on KUNIT
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index 48a67058f84e..e81e1ac4a919 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan
@@ -119,6 +119,8 @@ config UBSAN_SIGNED_WRAP
 	bool "Perform checking for signed arithmetic wrap-around"
 	default UBSAN
 	depends on !COMPILE_TEST
+	# The no_sanitize attribute was introduced in GCC with version 8.
+	depends on !CC_IS_GCC || GCC_VERSION >= 80000
 	depends on $(cc-option,-fsanitize=signed-integer-overflow)
 	help
 	  This option enables -fsanitize=signed-integer-overflow which checks
diff --git a/lib/memcpy_kunit.c b/lib/memcpy_kunit.c
index 30e00ef0bf2e..fd16e6ce53d1 100644
--- a/lib/memcpy_kunit.c
+++ b/lib/memcpy_kunit.c
@@ -309,9 +309,6 @@ static void set_random_nonzero(struct kunit *test, u8 *byte)
 
 static void init_large(struct kunit *test)
 {
-	if (!IS_ENABLED(CONFIG_MEMCPY_SLOW_KUNIT_TEST))
-		kunit_skip(test, "Slow test skipped. Enable with CONFIG_MEMCPY_SLOW_KUNIT_TEST=y");
-
 	/* Get many bit patterns. */
 	get_random_bytes(large_src, ARRAY_SIZE(large_src));
 
diff --git a/lib/overflow_kunit.c b/lib/overflow_kunit.c
index 65e8a72a83bf..4ef31b0bb74d 100644
--- a/lib/overflow_kunit.c
+++ b/lib/overflow_kunit.c
@@ -1172,6 +1172,24 @@ static void castable_to_type_test(struct kunit *test)
 #undef TEST_CASTABLE_TO_TYPE
 }
 
+struct foo {
+	int a;
+	u32 counter;
+	s16 array[] __counted_by(counter);
+};
+
+static void DEFINE_FLEX_test(struct kunit *test)
+{
+	DEFINE_RAW_FLEX(struct foo, two, array, 2);
+	DEFINE_FLEX(struct foo, eight, array, counter, 8);
+	DEFINE_FLEX(struct foo, empty, array, counter, 0);
+
+	KUNIT_EXPECT_EQ(test, __struct_size(two),
+			sizeof(struct foo) + sizeof(s16) + sizeof(s16));
+	KUNIT_EXPECT_EQ(test, __struct_size(eight), 24);
+	KUNIT_EXPECT_EQ(test, __struct_size(empty), sizeof(struct foo));
+}
+
 static struct kunit_case overflow_test_cases[] = {
 	KUNIT_CASE(u8_u8__u8_overflow_test),
 	KUNIT_CASE(s8_s8__s8_overflow_test),
@@ -1194,6 +1212,7 @@ static struct kunit_case overflow_test_cases[] = {
 	KUNIT_CASE(overflows_type_test),
 	KUNIT_CASE(same_type_test),
 	KUNIT_CASE(castable_to_type_test),
+	KUNIT_CASE(DEFINE_FLEX_test),
 	{}
 };