Following build warning / errors noticed while building x86_64 with clang on Linux next-20221025 tag. Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx> ## Build * kernel: 6.1.0-rc2 * git: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next * git branch: master * git commit: 89bf6e28373beef9577fa71f996a5f73a569617c * git describe: next-20221025 * test details: https://qa-reports.linaro.org/lkft/linux-next-master-sanity/build/next-20221025 ## Test Regressions (compared to next-20221024) Regressions found on x86_64: - clang-nightly-lkftconfig - clang-12-lkftconfig - clang-14-lkftconfig - clang-13-lkftconfig - clang-14-lkftconfig-kcsan make --silent --keep-going --jobs=8 O=/home/tuxbuild/.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/khugepaged.c:1729:7: error: variable 'index' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (!xas_nomem(&xas, GFP_KERNEL)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/khugepaged.c:2063:47: note: uninitialized use occurs here trace_mm_khugepaged_collapse_file(mm, hpage, index, is_shmem, ^~~~~ mm/khugepaged.c:1729:3: note: remove the 'if' if its condition is always false if (!xas_nomem(&xas, GFP_KERNEL)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/khugepaged.c:1716:6: error: variable 'index' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (result != SCAN_SUCCEED) ^~~~~~~~~~~~~~~~~~~~~~ mm/khugepaged.c:2063:47: note: uninitialized use occurs here trace_mm_khugepaged_collapse_file(mm, hpage, index, is_shmem, ^~~~~ mm/khugepaged.c:1716:2: note: remove the 'if' if its condition is always false if (result != SCAN_SUCCEED) ^~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/khugepaged.c:1705:15: note: initialize the variable 'index' to silence this warning pgoff_t index, end = start + HPAGE_PMD_NR; ^ = 0 mm/khugepaged.c:1729:7: error: variable 'nr' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (!xas_nomem(&xas, GFP_KERNEL)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/khugepaged.c:2064:15: note: uninitialized use occurs here addr, file, nr, result); ^~ mm/khugepaged.c:1729:3: note: remove the 'if' if its condition is always false if (!xas_nomem(&xas, GFP_KERNEL)) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/khugepaged.c:1716:6: error: variable 'nr' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (result != SCAN_SUCCEED) ^~~~~~~~~~~~~~~~~~~~~~ mm/khugepaged.c:2064:15: note: uninitialized use occurs here addr, file, nr, result); ^~ mm/khugepaged.c:1716:2: note: remove the 'if' if its condition is always false if (result != SCAN_SUCCEED) ^~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/khugepaged.c:1710:8: note: initialize the variable 'nr' to silence this warning int nr; ^ = 0 4 errors generated. make[3]: *** [scripts/Makefile.build:250: mm/khugepaged.o] Error 1 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 defconfig --kconfig-add https://raw.githubusercontent.com/Linaro/meta-lkft/kirkstone/meta/recipes-kernel/linux/files/lkft.config --kconfig-add https://raw.githubusercontent.com/Linaro/meta-lkft/kirkstone/meta/recipes-kernel/linux/files/lkft-crypto.config --kconfig-add https://raw.githubusercontent.com/Linaro/meta-lkft/kirkstone/meta/recipes-kernel/linux/files/distro-overrides.config --kconfig-add https://raw.githubusercontent.com/Linaro/meta-lkft/kirkstone/meta/recipes-kernel/linux/files/systemd.config --kconfig-add https://raw.githubusercontent.com/Linaro/meta-lkft/kirkstone/meta/recipes-kernel/linux/files/virtio.config --kconfig-add CONFIG_IGB=y --kconfig-add CONFIG_UNWINDER_FRAME_POINTER=y LLVM=1 LLVM_IAS=1 tuxmake --runtime podman --target-arch x86_64 --toolchain clang-14 --kconfig https://builds.tuxbuild.com/2Gc0JDbUOIN0veL39dqIt03qgEi/config LLVM=1 LLVM_IAS=1 Build link, - https://builds.tuxbuild.com/2Gc0JDbUOIN0veL39dqIt03qgEi/ -- Linaro LKFT https://lkft.linaro.org
