Re: powerpc: clang: arch/powerpc/kernel/exceptions-64s.S:2976: Error: junk at end of line: `0b01010'

[Nathan Chancellor]

On Tue, Jun 06, 2023 at 08:31:50AM -0700, Nathan Chancellor wrote:
> Hi Naresh,
> 
> On Tue, Jun 06, 2023 at 01:57:46PM +0530, Naresh Kamboju wrote:
> > Linux next-20230606 powerpc build failed.
> > 
> > Regressions found on powerpc:
> > 
> >  - build/clang-16-maple_defconfig
> >  - build/clang-nightly-maple_defconfig
> >  - build/clang-16-defconfig
> >  - build/clang-nightly-defconfig
> >  - build/clang-nightly-cell_defconfig
> >  - build/clang-16-cell_defconfig
> > 
> > Boot:
> > =====
> > make --silent --keep-going --jobs=8
> > O=/home/tuxbuild/.cache/tuxmake/builds/1/build ARCH=powerpc
> >  CROSS_COMPILE=powerpc64le-linux-gnu-
> >  HOSTCC=clang
> >  CC=clang
> >  LLVM=1
> >  LLVM_IAS=0
> >  LD=powerpc64le-linux-gnu-ld
> > 
> > arch/powerpc/kernel/exceptions-64s.S: Assembler messages:
> > arch/powerpc/kernel/exceptions-64s.S:2976: Error: junk at end of line: `0b01010'
> > arch/powerpc/kernel/exceptions-64s.S:2996: Error: junk at end of line: `0b01010'
> > arch/powerpc/kernel/exceptions-64s.S:3011: Error: junk at end of line: `0b01010'
> > arch/powerpc/kernel/exceptions-64s.S:3029: Error: junk at end of line: `0b01010'
> > arch/powerpc/kernel/exceptions-64s.S:3049: Error: junk at end of line: `0b01010'
> > arch/powerpc/kernel/exceptions-64s.S:3096: Error: junk at end of line: `0b01010'
> > clang: error: assembler command failed with exit code 1 (use -v to see
> > invocation)
> > make[4]: *** [scripts/Makefile.build:374: arch/powerpc/kernel/head_64.o] Error 1
> > arch/powerpc/kernel/entry_64.S: Assembler messages:
> > arch/powerpc/kernel/entry_64.S:174: Error: junk at end of line: `0b01010'
> > clang: error: assembler command failed with exit code 1 (use -v to see
> > invocation)
> > make[4]: *** [scripts/Makefile.build:374:
> > arch/powerpc/kernel/entry_64.o] Error 1
> > make[4]: Target 'arch/powerpc/kernel/' not remade because of errors.
> > make[3]: *** [scripts/Makefile.build:494: arch/powerpc/kernel] Error 2
> > arch/powerpc/lib/copyuser_power7.S: Assembler messages:
> > arch/powerpc/lib/copyuser_power7.S:305: Error: junk at end of line: `0b01000'
> > arch/powerpc/lib/copyuser_power7.S:306: Error: junk at end of line: `0b01010'
> > arch/powerpc/lib/copyuser_power7.S:308: Error: junk at end of line: `0b01000'
> > arch/powerpc/lib/copyuser_power7.S:309: Error: junk at end of line: `0b01010'
> > arch/powerpc/lib/copyuser_power7.S:311: Error: junk at end of line: `0b01010'
> > clang: error: assembler command failed with exit code 1 (use -v to see
> > invocation)
> > make[4]: *** [scripts/Makefile.build:374:
> > arch/powerpc/lib/copyuser_power7.o] Error 1
> > arch/powerpc/lib/copypage_power7.S: Assembler messages:
> > arch/powerpc/lib/copypage_power7.S:34: Error: junk at end of line: `0b01000'
> > arch/powerpc/lib/copypage_power7.S:35: Error: junk at end of line: `0b01010'
> > arch/powerpc/lib/copypage_power7.S:37: Error: junk at end of line: `0b01000'
> > arch/powerpc/lib/copypage_power7.S:38: Error: junk at end of line: `0b01010'
> > arch/powerpc/lib/copypage_power7.S:40: Error: junk at end of line: `0b01010'
> > clang: error: assembler command failed with exit code 1 (use -v to see
> > invocation)
> > make[4]: *** [scripts/Makefile.build:374:
> > arch/powerpc/lib/copypage_power7.o] Error 1
> > arch/powerpc/lib/memcpy_power7.S: Assembler messages:
> > arch/powerpc/lib/memcpy_power7.S:250: Error: junk at end of line: `0b01000'
> > arch/powerpc/lib/memcpy_power7.S:251: Error: junk at end of line: `0b01010'
> > arch/powerpc/lib/memcpy_power7.S:252: Error: junk at end of line: `0b01000'
> > arch/powerpc/lib/memcpy_power7.S:253: Error: junk at end of line: `0b01010'
> > arch/powerpc/lib/memcpy_power7.S:255: Error: junk at end of line: `0b01010'
> > clang: error: assembler command failed with exit code 1 (use -v to see
> > invocation)
> > make[4]: *** [scripts/Makefile.build:374:
> > arch/powerpc/lib/memcpy_power7.o] Error 1
> > 
> > Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> 
> Thank you for the report, this is caused by the move of CLANG_FLAGS from
> KBUILD_{A,C}FLAGS to KBUILD_CPPFLAGS, as as-option does not contain
> KBUILD_CPPFLAGS, so we fail to pass necessary flags to the assembler.
> The following diff resolves this particular issue for me, can you test
> it to make sure it works for you?  I will write up a changelog and sent
> along a formal patch later today.

I have now sent [1] to address this, please consider providing a tag
there assuming it passes all of your tests.

[1]: https://lore.kernel.org/20230606-fix-as-option-after-clang_flags-move-v1-1-a7f7b23a35e3@xxxxxxxxxx/

Cheers,
Nathan

> diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
> index 437013f8def3..e31f18625fcf 100644
> --- a/scripts/Makefile.compiler
> +++ b/scripts/Makefile.compiler
> @@ -32,7 +32,7 @@ try-run = $(shell set -e;		\
>  # Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,)
>  
>  as-option = $(call try-run,\
> -	$(CC) -Werror $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2))
> +	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2))
>  
>  # as-instr
>  # Usage: aflags-y += $(call as-instr,instr,option1,option2)
>