[PATCH 07/11] efi/libstub: Disable some warnings for x86{,_64}

From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: linux-efi@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org>,
	Arend van Spriel <arend.vanspriel@broadcom.com>,
	Bhupesh Sharma <bhsharma@redhat.com>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@intel.com>,
	Eric Snowberg <eric.snowberg@oracle.com>,
	Hans de Goede <hdegoede@redhat.com>,
	Joe Perches <joe@perches.com>, Jon Hunter <jonathanh@nvidia.com>,
	Julien Thierry <julien.thierry@arm.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
	Sedat Dilek <sedat.dilek@gmail.com>,
	YiFei Zhu <zhuyifei1999@gmail.com>
Subject: [PATCH 07/11] efi/libstub: Disable some warnings for x86{,_64}
Date: Thu, 29 Nov 2018 18:12:26 +0100	[thread overview]
Message-ID: <20181129171230.18699-8-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20181129171230.18699-1-ard.biesheuvel@linaro.org>

From: Nathan Chancellor <natechancellor@gmail.com>

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@gmail.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 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

