The x86_64 builds failed with clang-19 and clang-nightly on the Linux next-20241125 tag. Same build pass with gcc-13.

First seen on Linux next-20241125 tag. Good: next-20241122 Bad: next-20241125 and next-20241126

x86_64: build: * clang-19-lkftconfig * clang-nightly-lkftconfig-lto-full * clang-nightly-lkftconfig * clang-19-lkftconfig-kcsan * korg-clang-19-lkftconfig-lto-full * clang-nightly-lkftconfig-lto-thing * clang-nightly-lkftconfig-kselftest * clang-19-x86_64_defconfig * rustclang-nightly-lkftconfig-kselftest * clang-19-lkftconfig-no-kselftest-frag * korg-clang-19-lkftconfig-hardening * korg-clang-19-lkftconfig-lto-thing * clang-19-lkftconfig-compat * clang-nightly-lkftconfig-hardening * clang-nightly-x86_64_defconfig

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

Build error: --------- fs/netfs/read_retry.c:235:20: error: variable 'subreq' is uninitialized when used here [-Werror,-Wuninitialized] 235 | if (list_is_last(&subreq->rreq_link, &stream->subrequests)) | ^~~~~~ fs/netfs/read_retry.c:28:36: note: initialize the variable 'subreq' to silence this warning 28 | struct netfs_io_subrequest *subreq; | ^ | = NULL 1 error generated. make[5]: *** [scripts/Makefile.build:194: fs/netfs/read_retry.o] Error 1

Build image: ----------- - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20241126/tes... - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20241126/tes... - https://storage.tuxsuite.com/public/linaro/lkft/builds/2pNKzjvChfT6aOWplZaZe...

Steps to reproduce: ------------ - tuxmake --runtime podman --target-arch x86_64 --toolchain clang-19 --kconfig https://storage.tuxsuite.com/public/linaro/lkft/builds/2pNKzjvChfT6aOWplZaZe... LLVM=1 LLVM_IAS=1

The git log shows $ git log --oneline next-20241122..next-20241125 -- fs/netfs/read_retry.c 1bd9011ee163e netfs: Change the read result collector to only use one work item 5c962f9982cd9 netfs: Don't use bh spinlock 3c8a83f74e0ea netfs: Drop the was_async arg from netfs_read_subreq_terminated() 2029a747a14d2 netfs: Abstract out a rolling folio buffer implementation

metadata: ---- git describe: next-20241125 and next-20241126 git repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git sha: ed9a4ad6e5bd3a443e81446476718abebee47e82 kernel config: https://storage.tuxsuite.com/public/linaro/lkft/builds/2pNKzjvChfT6aOWplZaZe... build url: https://storage.tuxsuite.com/public/linaro/lkft/builds/2pNKzjvChfT6aOWplZaZe... toolchain: clang-19 and clang-nightly config: defconfig, lkftconfig etc arch: x86_64

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