The following build warnings / errors noticed on the riscv and s390 with allyesconfig build on the Linux next-20250912 tag.

Regression Analysis: - New regression? yes - Reproducibility? yes

Build regression: next-20250912 mm/kasan/shadow.c 'kasan_populate_vmalloc_pte' pgtable.h error statement with no effect [-Werror=unused-value]

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

$ git log --oneline next-20250911..next-20250912 -- mm/kasan/shadow.c aed53ec0b797a mm: introduce local state for lazy_mmu sections 307f2dc9b308e kasan: introduce ARCH_DEFER_KASAN and unify static key across modes

## Test log In file included from include/linux/kasan.h:37, from mm/kasan/shadow.c:14: mm/kasan/shadow.c: In function 'kasan_populate_vmalloc_pte': include/linux/pgtable.h:247:41: error: statement with no effect [-Werror=unused-value] 247 | #define arch_enter_lazy_mmu_mode() (LAZY_MMU_DEFAULT) | ^ mm/kasan/shadow.c:322:9: note: in expansion of macro 'arch_enter_lazy_mmu_mode' 322 | arch_enter_lazy_mmu_mode(); | ^~~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/shadow.c: In function 'kasan_depopulate_vmalloc_pte': include/linux/pgtable.h:247:41: error: statement with no effect [-Werror=unused-value] 247 | #define arch_enter_lazy_mmu_mode() (LAZY_MMU_DEFAULT) | ^ mm/kasan/shadow.c:497:9: note: in expansion of macro 'arch_enter_lazy_mmu_mode' 497 | arch_enter_lazy_mmu_mode(); | ^~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors

## Source * Kernel version: 6.17.0-rc5 * Git tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git * Git describe: 6.17.0-rc5-next-20250912 * Git commit: 590b221ed4256fd6c34d3dea77aa5bd6e741bbc1 * Architectures: riscv, s390 * Toolchains: gcc (Debian 13.3.0-16) 13.3.0 * Kconfigs: allyesconfig

## Build * Build log: https://qa-reports.linaro.org/api/testruns/29863344/log_file/ * Build details: https://regressions.linaro.org/lkft/linux-next-master/next-20250912/log-pars... * Build plan: https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/builds/32aTGVWBLz... * Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/32aTGVWBLzkF7PsIq9FBt... * Kernel config: https://storage.tuxsuite.com/public/linaro/lkft/builds/32aTGVWBLzkF7PsIq9FBt...

## Steps to reproduce $ tuxmake --runtime podman --target-arch riscv --toolchain gcc-13 --kconfig allyesconfig

-- Linaro LKFT