From: Nathan Chancellor <natechancellor@xxxxxxxxx> When building the kernel with Clang, some disabled warnings appear because this Makefile overrides KBUILD_CFLAGS for x86{,_64}. Add them to this list so that the build is clean again. -Wpointer-sign was disabled for the whole kernel before the beginning of git history. -Waddress-of-packed-member was disabled for the whole kernel in commit bfb38988c51e ("kbuild: clang: Disable 'address-of-packed-member' warning") and for x86/boot/compressed in commit 20c6c1890455 ("x86/boot: Disable the address-of-packed-member compiler warning"). -Wgnu was disabled for the whole kernel in commit 61163efae020 ("kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang") and for x86/boot/compressed in commit 6c3b56b19730 ("x86/boot: Disable Clang warnings about GNU extensions"). Link: https://github.com/ClangBuiltLinux/linux/issues/112 Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Reviewed-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> Tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> --- drivers/firmware/efi/libstub/Makefile | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index c51627660dbb..d9845099635e 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -9,7 +9,10 @@ cflags-$(CONFIG_X86_32) := -march=i386 cflags-$(CONFIG_X86_64) := -mcmodel=small cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -O2 \ -fPIC -fno-strict-aliasing -mno-red-zone \ - -mno-mmx -mno-sse -fshort-wchar + -mno-mmx -mno-sse -fshort-wchar \ + -Wno-pointer-sign \ + $(call cc-disable-warning, address-of-packed-member) \ + $(call cc-disable-warning, gnu) # arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly # disable the stackleak plugin -- 2.19.1