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From:   Naresh Kamboju <naresh.kamboju@linaro.org>
Date:   Tue, 23 Aug 2022 15:44:06 +0530
Message-ID: <CA+G9fYsm_2WZncWJbwkJkbnOJFvnC76jQdUWkHhyih4GRKjMGg@mail.gmail.com>
Subject: [next] mm/pagewalk.c:318:12: error: variable 'err' is used
 uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
To:     open list <linux-kernel@vger.kernel.org>,
        Linux-Next Mailing List <linux-next@vger.kernel.org>,
        regressions@lists.linux.dev, lkft-triage@lists.linaro.org,
        linux-mm <linux-mm@kvack.org>
Cc:     Rolf Eike Beer <eb@emlix.com>,
        Andrew Morton <akpm@linux-foundation.org>
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x86_64 defconfig builds failed on Linux next-20220823 tag with clang toolchain.

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>

Regressions found on x86_64:
   - build-clang-13-x86_64_defconfig
   - build-clang-14-lkftconfig-kcsan
   - build-clang-nightly-lkftconfig
   - build-clang-11-x86_64_defconfig
   - build-clang-14-lkftconfig
   - build-clang-nightly-x86_64_defconfig
   - build-clang-14-x86_64_defconfig
   - build-clang-13-lkftconfig
   - build-clang-12-x86_64_defconfig
   - build-clang-12-lkftconfig

Regressions found on i386:
   - build-clang-11-defconfig
   - build-clang-nightly-lkftconfig
   - build-clang-nightly-defconfig
   - build-clang-14-lkftconfig
   - build-clang-14-defconfig
   - build-clang-12-defconfig
   - build-clang-13-lkftconfig
   - build-clang-13-defconfig
   - build-clang-12-lkftconfig

make --silent --keep-going --jobs=8 O=/home/tux   -
build-.cache/tuxmake/builds/1/build LLVM=1 LLVM_IAS=1 ARCH=x86_64
CROSS_COMPILE=x86_64-linux-gnu- 'HOSTCC=sccache clang' 'CC=sccache
clang' olddefconfig
.config:5286:warning: override: UNWINDER_FRAME_POINTER changes choice state
make --silent --keep-going --jobs=8 O=/home/tux   -
build-.cache/tuxmake/builds/1/build LLVM=1 LLVM_IAS=1 ARCH=x86_64
CROSS_COMPILE=x86_64-linux-gnu- 'HOSTCC=sccache clang' 'CC=sccache
clang'

mm/pagewalk.c:318:12: error: variable 'err' is used uninitialized
whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
                else if (ops->pte_hole)
                         ^~~~~~~~~~~~~
mm/pagewalk.c:321:7: note: uninitialized use occurs here
                if (err)
                    ^~~
mm/pagewalk.c:318:8: note: remove the 'if' if its condition is always true
                else if (ops->pte_hole)
                     ^~~~~~~~~~~~~~~~~~
mm/pagewalk.c:311:10: note: initialize the variable 'err' to silence
this warning
                int err;
                       ^
                        = 0
1 error generated.

metadata:
Build: https://builds.tuxbuild.com/2DkF28RfJ2VeMSGwDNhsXXu3dbo/
config: https://builds.tuxbuild.com/2DkF28RfJ2VeMSGwDNhsXXu3dbo/config
git_describe: next-20220823
git_repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next
git_sha: 05477f3653b82d8b3bcf39d2937d9893124976db
git_short_log: 05477f3653b8 ("Add linux-next specific files for 20220823")
toolchain: clang

Steps to reproduce:
------------------------
# To install tuxmake on your system globally:
# sudo pip3 install -U tuxmake
#
# See https://docs.tuxmake.org/ for complete documentation.
# Original tuxmake command with fragments listed below.

# tuxmake --runtime podman --target-arch x86_64 --toolchain clang-14
--kconfig x86_64_defconfig LLVM=1 LLVM_IAS=1

--
Linaro LKFT
https://lkft.linaro.org