This is a note to let you know that I've just added the patch titled kernel: don't call do_exit() for PF_IO_WORKER threads to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kernel-don-t-call-do_exit-for-pf_io_worker-threads.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e11f9f61752f252ee19e9c0dee22218f9078a75b Mon Sep 17 00:00:00 2001 From: Jens Axboe <axboe@xxxxxxxxx> Date: Fri, 26 Mar 2021 08:57:10 -0600 Subject: kernel: don't call do_exit() for PF_IO_WORKER threads From: Jens Axboe <axboe@xxxxxxxxx> [ Upstream commit 10442994ba195efef6fdcc0c3699e4633cb5161b ] Right now we're never calling get_signal() from PF_IO_WORKER threads, but in preparation for doing so, don't handle a fatal signal for them. The workers have state they need to cleanup when exiting, so just return instead of calling do_exit() on their behalf. The threads themselves will detect a fatal signal and do proper shutdown. Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/signal.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2755,13 +2755,21 @@ relock: } /* + * PF_IO_WORKER threads will catch and exit on fatal signals + * themselves. They have cleanup that must be performed, so + * we cannot call do_exit() on their behalf. + */ + if (current->flags & PF_IO_WORKER) + goto out; + + /* * Death signals, no core dump. */ do_group_exit(ksig->info.si_signo); /* NOTREACHED */ } spin_unlock_irq(&sighand->siglock); - +out: ksig->sig = signr; return ksig->sig > 0; } Patches currently in stable-queue which might be from axboe@xxxxxxxxx are queue-5.10/x86-process-setup-io_threads-more-like-normal-user-space-threads.patch queue-5.10/powerpc-add-support-for-tif_notify_signal.patch queue-5.10/eventfd-provide-a-eventfd_signal_mask-helper.patch queue-5.10/fs-provide-locked-helper-variant-of-close_fd_get_file.patch queue-5.10/relay-fix-type-mismatch-when-allocating-memory-in-re.patch queue-5.10/eventfd-change-int-to-__u64-in-eventfd_signal-ifndef.patch queue-5.10/io_uring-pass-in-epoll_uring_wake-for-eventfd-signaling-and-wakeups.patch queue-5.10/blk-mq-fix-possible-memleak-when-register-hctx-faile.patch queue-5.10/fix-handling-of-nd-depth-on-lookup_cached-failures-in-try_to_unlazy.patch queue-5.10/net-provide-__sys_shutdown_sock-that-takes-a-socket.patch queue-5.10/task_work-unconditionally-run-task_work-from-get_signal.patch queue-5.10/openrisc-add-support-for-tif_notify_signal.patch queue-5.10/signal-add-task_sigpending-helper.patch queue-5.10/net-remove-cmsg-restriction-from-io_uring-based-send-recvmsg-calls.patch queue-5.10/alpha-add-support-for-tif_notify_signal.patch queue-5.10/nios32-add-support-for-tif_notify_signal.patch queue-5.10/ia64-don-t-call-handle_signal-unless-there-s-actually-a-signal-queued.patch queue-5.10/task_work-remove-legacy-twa_signal-path.patch queue-5.10/revert-proc-don-t-allow-async-path-resolution-of-proc-self-components.patch queue-5.10/m68k-add-support-for-tif_notify_signal.patch queue-5.10/s390-add-support-for-tif_notify_signal.patch queue-5.10/um-add-support-for-tif_notify_signal.patch queue-5.10/tools-headers-uapi-sync-openat2.h-with-the-kernel-sources.patch queue-5.10/kernel-provide-create_io_thread-helper.patch queue-5.10/iov_iter-add-helper-to-save-iov_iter-state.patch queue-5.10/arc-unbork-5.11-bootup-fix-snafu-in-_tif_notify_signal-handling.patch queue-5.10/arch-ensure-parisc-powerpc-handle-pf_io_worker-in-copy_thread.patch queue-5.10/csky-add-support-for-tif_notify_signal.patch queue-5.10/arm-add-support-for-tif_notify_signal.patch queue-5.10/kernel-stop-masking-signals-in-create_io_thread.patch queue-5.10/fs-expose-lookup_cached-through-openat2-resolve_cached.patch queue-5.10/task_work-add-helper-for-more-targeted-task_work-canceling.patch queue-5.10/nds32-add-support-for-tif_notify_signal.patch queue-5.10/signal-kill-jobctl_task_work.patch queue-5.10/hexagon-add-support-for-tif_notify_signal.patch queue-5.10/sh-add-support-for-tif_notify_signal.patch queue-5.10/riscv-add-support-for-tif_notify_signal.patch queue-5.10/h8300-add-support-for-tif_notify_signal.patch queue-5.10/io_uring-import-5.15-stable-io_uring.patch queue-5.10/sparc-add-support-for-tif_notify_signal.patch queue-5.10/blktrace-fix-output-non-blktrace-event-when-blk_clas.patch queue-5.10/eventpoll-add-epoll_uring_wake-poll-wakeup-flag.patch queue-5.10/parisc-add-support-for-tif_notify_signal.patch queue-5.10/entry-add-support-for-tif_notify_signal.patch queue-5.10/x86-wire-up-tif_notify_signal.patch queue-5.10/task_work-use-tif_notify_signal-if-available.patch queue-5.10/drbd-fix-an-invalid-memory-access-caused-by-incorrec.patch queue-5.10/kernel-don-t-call-do_exit-for-pf_io_worker-threads.patch queue-5.10/kernel-allow-fork-with-tif_notify_signal-pending.patch queue-5.10/pata_ipx4xx_cf-fix-unsigned-comparison-with-less-tha.patch queue-5.10/mips-add-support-for-tif_notify_signal.patch queue-5.10/xtensa-add-support-for-tif_notify_signal.patch queue-5.10/c6x-add-support-for-tif_notify_signal.patch queue-5.10/microblaze-add-support-for-tif_notify_signal.patch queue-5.10/net-add-accept-helper-not-installing-fd.patch queue-5.10/ia64-add-support-for-tif_notify_signal.patch queue-5.10/arm64-add-support-for-tif_notify_signal.patch queue-5.10/arc-add-support-for-tif_notify_signal.patch queue-5.10/revert-proc-don-t-allow-async-path-resolution-of-proc-thread-self-components.patch queue-5.10/fs-make-do_renameat2-take-struct-filename.patch queue-5.10/kernel-remove-checking-for-tif_notify_signal.patch queue-5.10/arch-setup-pf_io_worker-threads-like-pf_kthread.patch queue-5.10/nvme-pci-fix-mempool-alloc-size.patch queue-5.10/fs-add-support-for-lookup_cached.patch