[PATCH v2 2/2] hardening: Enable i386 FORTIFY_SOURCE on Clang 16+

[Kees Cook]

The i386 regparm bug exposed with FORTIFY_SOURCE with Clang was fixed
in Clang 16[1].

Link: https://github.com/llvm/llvm-project/commit/c167c0a4dcdb998affb2756ce76903a12f7d8ca5 [1]
Signed-off-by: Kees Cook <kees at kernel.org>
---
 arch/x86/Makefile          | 2 +-
 security/Kconfig.hardening | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index d25ed25fb7d9..917459d1ad40 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -137,7 +137,7 @@ ifeq ($(CONFIG_X86_32),y)
         include $(srctree)/arch/x86/Makefile_32.cpu
         KBUILD_CFLAGS += $(cflags-y)
 
-    ifeq ($(CONFIG_CC_IS_CLANG),y)
+    ifneq ($(call clang-min-version, 160000),y)
         # temporary until string.h is fixed
         KBUILD_CFLAGS += -ffreestanding
     endif
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index 23ffb0d7c845..c17366ce8224 100644
--- a/security/Kconfig.hardening
+++ b/security/Kconfig.hardening
@@ -286,7 +286,7 @@ config FORTIFY_SOURCE
 	bool "Harden common str/mem functions against buffer overflows"
 	depends on ARCH_HAS_FORTIFY_SOURCE
 	# https://github.com/llvm/llvm-project/issues/53645
-	depends on !CC_IS_CLANG || !X86_32
+	depends on !X86_32 || !CC_IS_CLANG || CLANG_VERSION >= 160000
 	help
 	  Detect overflows of buffers in common string and memory functions
 	  where the compiler can determine and validate the buffer sizes.
-- 
2.34.1