[PATCH v2 00/14] Remove clang's -Qunused-arguments from KBUILD_CPPFLAGS

[Nathan Chancellor]

Hi Naresh,

On Mon, Jan 23, 2023 at 07:28:10PM +0530, Naresh Kamboju wrote:
> FYI,
> [ please provide comments, feedback and improvements on build/ ltp smoke tests ]
> 
> LKFT test farm have fetched your patch series [1]
> [PATCH v2 00/14] Remove clang's -Qunused-arguments from KBUILD_CPPFLAGS
>  [1] https://lore.kernel.org/llvm/20221228-drop-qunused-arguments-v2-0-9adbddd20d86@kernel.org/

Thank you a lot for testing this series, it is much appreciated!

It looks like this was applied on top of 6.2-rc3 if I am reading your
logs right but your mainline testing is recent, 6.2-rc5. I think the
errors you are seeing here are just existing mainline regressions that
were later fixed.

> Following build warnings and errors reported.
> 
> sh:
> gcc-11-defconfig — FAIL
> gcc-11-shx3_defconfig — FAIL
> https://qa-reports.linaro.org/~anders.roxell/linux-mainline-patches/build/https___lore_kernel_org_llvm_20221228-drop-qunused-arguments-v2-1-9adbddd20d86_kernel_org/testrun/14221835/suite/build/tests/
> 
> mainline getting passed.
> https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.2-rc5/testrun/14298156/suite/build/test/gcc-11-defconfig/history/
> https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.2-rc5/testrun/14298156/suite/build/test/gcc-11-shx3_defconfig/history/
> 
> Build error:
> In function 'follow_pmd_mask',
>     inlined from 'follow_pud_mask' at /builds/linux/mm/gup.c:735:9,
>     inlined from 'follow_p4d_mask' at /builds/linux/mm/gup.c:752:9,
>     inlined from 'follow_page_mask' at /builds/linux/mm/gup.c:809:9:
> /builds/linux/include/linux/compiler_types.h:358:45: error: call to
> '__compiletime_assert_263' declared with attribute error: Unsupported
> access size for {READ,WRITE}_ONCE().
>   358 |         _compiletime_assert(condition, msg,
> __compiletime_assert_, __COUNTER__)

I think this was fixed with mainline commit 526970be53d5 ("sh/mm: Fix
pmd_t for real"), released in 6.2-rc4. You can see a previous build
failing in the same manner:

https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.2-rc3-9-g5a41237ad1d4/testrun/14056384/suite/build/tests/

> s390:
> clang-15-defconfig — FAIL
> https://qa-reports.linaro.org/~anders.roxell/linux-mainline-patches/build/https___lore_kernel_org_llvm_20221228-drop-qunused-arguments-v2-1-9adbddd20d86_kernel_org/testrun/14221913/suite/build/tests/
> 
> mainline getting passed.
> https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.2-rc5/testrun/14300495/suite/build/test/clang-15-defconfig/history/
> 
> Build error:
> make --silent --keep-going --jobs=8
> O=/home/tuxbuild/.cache/tuxmake/builds/1/build LLVM_IAS=0 ARCH=s390
> CROSS_COMPILE=s390x-linux-gnu- 'HOSTCC=sccache clang' 'CC=sccache
> clang'
> `.exit.text' referenced in section `__jump_table' of fs/fuse/inode.o:
> defined in discarded section `.exit.text' of fs/fuse/inode.o
> `.exit.text' referenced in section `__jump_table' of fs/fuse/inode.o:
> defined in discarded section `.exit.text' of fs/fuse/inode.o
> `.exit.text' referenced in section `__bug_table' of crypto/algboss.o:
> defined in discarded section `.exit.text' of crypto/algboss.o
> `.exit.text' referenced in section `__bug_table' of drivers/scsi/sd.o:
> defined in discarded section `.exit.text' of drivers/scsi/sd.o
> `.exit.text' referenced in section `__jump_table' of drivers/md/md.o:
> defined in discarded section `.exit.text' of drivers/md/md.o
> `.exit.text' referenced in section `__jump_table' of drivers/md/md.o:
> defined in discarded section `.exit.text' of drivers/md/md.o
> `.exit.text' referenced in section `.altinstructions' of
> drivers/md/md.o: defined in discarded section `.exit.text' of
> drivers/md/md.o
> `.exit.text' referenced in section `.altinstructions' of
> drivers/md/md.o: defined in discarded section `.exit.text' of
> drivers/md/md.o
> `.exit.text' referenced in section `.altinstructions' of
> net/iucv/iucv.o: defined in discarded section `.exit.text' of
> net/iucv/iucv.o
> `.exit.text' referenced in section `__bug_table' of
> drivers/s390/cio/qdio_thinint.o: defined in discarded section
> `.exit.text' of drivers/s390/cio/qdio_thinint.o
> `.exit.text' referenced in section `__bug_table' of
> drivers/s390/net/qeth_l3_main.o: defined in discarded section
> `.exit.text' of drivers/s390/net/qeth_l3_main.o
> `.exit.text' referenced in section `__bug_table' of
> drivers/s390/net/qeth_l3_main.o: defined in discarded section
> `.exit.text' of drivers/s390/net/qeth_l3_main.o
> s390x-linux-gnu-ld: BFD (GNU Binutils for Debian) 2.35.2 assertion
> fail ../../bfd/elf64-s390.c:3349
> make[2]: *** [/builds/linux/scripts/Makefile.vmlinux:34: vmlinux] Error 1

This should be fixed with mainline commit a494398bde27 ("s390: define
RUNTIME_DISCARD_EXIT to fix link error with GNU ld < 2.36"), released in
6.2-rc4 as well. Same as before, visible in mainline at one point
without this series:

https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.2-rc3-9-g5a41237ad1d4/testrun/14057142/suite/build/tests/

> But,
> Build and boot pass on arm64, arm, x86_64 and i386.
> Build test performed for mips, parisc, riscv, s390, sh, sparc and
> powerpc (known build errors for maple_defconfig and cell_defconfig),

Good to hear!

Please consider retesting this series on top of 6.2-rc5 or testing the
current kbuild tree, which has this series applied in it:

https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git/log/?h=for-next

Cheers,
Nathan