This is a note to let you know that I've just added the patch titled
powerpc: Remove linker flag from KBUILD_AFLAGS
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-remove-linker-flag-from-kbuild_aflags.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8672a97c1b3b48054eb56f3b7b26747feccd66bb
Author: Nathan Chancellor <nathan@xxxxxxxxxx>
Date: Wed Jan 11 20:05:02 2023 -0700
powerpc: Remove linker flag from KBUILD_AFLAGS
[ Upstream commit 31f48f16264bc70962fb3e7ec62da64d0a2ba04a ]
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it
points out that KBUILD_AFLAGS contains a linker flag, which will be
unused:
clang: error: -Wl,-a32: 'linker' input unused [-Werror,-Wunused-command-line-argument]
This was likely supposed to be '-Wa,-a$(BITS)'. However, this change is
unnecessary, as all supported versions of clang and gcc will pass '-a64'
or '-a32' to GNU as based on the value of '-m'; the behavior of the
latest stable release of the oldest supported major version of each
compiler is shown below and each compiler's latest release exhibits the
same behavior (GCC 12.2.0 and Clang 15.0.6).
$ powerpc64-linux-gcc --version | head -1
powerpc64-linux-gcc (GCC) 5.5.0
$ powerpc64-linux-gcc -m64 -### -x assembler-with-cpp -c -o /dev/null /dev/null &| grep 'as '
.../as -a64 -mppc64 -many -mbig -o /dev/null /tmp/cctwuBzZ.s
$ powerpc64-linux-gcc -m32 -### -x assembler-with-cpp -c -o /dev/null /dev/null &| grep 'as '
.../as -a32 -mppc -many -mbig -o /dev/null /tmp/ccaZP4mF.sg
$ clang --version | head -1
Ubuntu clang version 11.1.0-++20211011094159+1fdec59bffc1-1~exp1~20211011214622.5
$ clang --target=powerpc64-linux-gnu -fno-integrated-as -m64 -### \
-x assembler-with-cpp -c -o /dev/null /dev/null &| grep gnu-as
"/usr/bin/powerpc64-linux-gnu-as" "-a64" "-mppc64" "-many" "-o" "/dev/null" "/tmp/null-80267c.s"
$ clang --target=powerpc64-linux-gnu -fno-integrated-as -m64 -### \
-x assembler-with-cpp -c -o /dev/null /dev/null &| grep gnu-as
"/usr/bin/powerpc64-linux-gnu-as" "-a32" "-mppc" "-many" "-o" "/dev/null" "/tmp/null-ab8f8d.s"
Remove this flag altogether to avoid future issues.
Fixes: 1421dc6d4829 ("powerpc/kbuild: Use flags variables rather than overriding LD/CC/AS")
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Tested-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
Tested-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 5987ae0d8fbbb..9b33cd4e0e177 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -109,7 +109,7 @@ aflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mlittle-endian
ifeq ($(HAS_BIARCH),y)
KBUILD_CFLAGS += -m$(BITS)
-KBUILD_AFLAGS += -m$(BITS) -Wl,-a$(BITS)
+KBUILD_AFLAGS += -m$(BITS)
KBUILD_LDFLAGS += -m elf$(BITS)$(LDEMULATION)
KBUILD_ARFLAGS += --target=elf$(BITS)-$(GNUTARGET)
endif
