Regressions noticed while building x86_64 and i386 builds with clang-nightly and clang-20 toolchains on the Linux next-20250725 tag.

First seen on the Linux next-20250725 Good: next-20250724 Bad: next-20250725

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

## Build regressions * i386, build - clang-20-defconfig - clang-nightly-defconfig

* x86_64, build - clang-20-allyesconfig - clang-20-lkftconfig - clang-20-lkftconfig-compat - clang-20-lkftconfig-kcsan - clang-20-lkftconfig-no-kselftest-frag - clang-20-x86_64_defconfig - clang-nightly-lkftconfig - clang-nightly-lkftconfig-hardening - clang-nightly-lkftconfig-kselftest - clang-nightly-lkftconfig-lto-full - clang-nightly-lkftconfig-lto-thing - clang-nightly-x86_64_defconfig - gcc-13-allyesconfig - korg-clang-20-lkftconfig-hardening - korg-clang-20-lkftconfig-lto-full - korg-clang-20-lkftconfig-lto-thing - rustclang-nightly-lkftconfig-kselftest

Build regression: next-20250725 i386 x86_64 virtio_ring.c error variable 'id' is uninitialized when used here [-Werror,-Wuninitialized]

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

## Build log drivers/virtio/virtio_ring.c:2113:40: error: variable 'id' is uninitialized when used here [-Werror,-Wuninitialized] 2113 | BAD_RING(vq, "id %u out of range\n", id); | ^~ drivers/virtio/virtio_ring.c:2077:19: note: initialize the variable 'id' to silence this warning 2077 | u16 last_used, id, last_used_idx; | ^ | = 0 1 error generated.

## Source * Git tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git * Project: https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20250725/ * Git sha: d7af19298454ed155f5cf67201a70f5cf836c842 * Git describe: 6.16.0-rc7-next-20250725 * kernel version: next-20250725 * Architectures: i386, x86_64 * Toolchains: clang-nightly clang-20 * Kconfigs: defconfig hardening lto-thing lto-full

## Test * Test log: https://qa-reports.linaro.org/api/testruns/29243926/log_file/ * Test details: https://regressions.linaro.org/lkft/linux-next-master/next-20250725/build/cl... * Test run: https://regressions.linaro.org/lkft/linux-next-master/next-20250725/testruns... * Test history: https://regressions.linaro.org/lkft/linux-next-master/next-20250725/log-pars... * Test plan: https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/builds/30LiHiVcyj... * Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/30LiHiVcyjXbMOk2IAEwl... * Kernel config: https://storage.tuxsuite.com/public/linaro/lkft/builds/30LiHiVcyjXbMOk2IAEwl...

## steps to reproduce * tuxmake --runtime podman --target-arch i386 --toolchain clang-nightly --kconfig defconfig LLVM=1 LLVM_IAS=1

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