# git rev-parse -q --verify 06af8679449d4ed282df13191fc52d5ba28ec536^{commit}
06af8679449d4ed282df13191fc52d5ba28ec536
already have revision, skipping fetch
# git checkout -q -f -B kisskb 06af8679449d4ed282df13191fc52d5ba28ec536
# git clean -qxdf
# < git log -1
# commit 06af8679449d4ed282df13191fc52d5ba28ec536
# Author: Eric W. Biederman <ebiederm@xmission.com>
# Date:   Thu Jun 10 15:11:11 2021 -0500
# 
#     coredump: Limit what can interrupt coredumps
#     
#     Olivier Langlois has been struggling with coredumps being incompletely written in
#     processes using io_uring.
#     
#     Olivier Langlois <olivier@trillion01.com> writes:
#     > io_uring is a big user of task_work and any event that io_uring made a
#     > task waiting for that occurs during the core dump generation will
#     > generate a TIF_NOTIFY_SIGNAL.
#     >
#     > Here are the detailed steps of the problem:
#     > 1. io_uring calls vfs_poll() to install a task to a file wait queue
#     >    with io_async_wake() as the wakeup function cb from io_arm_poll_handler()
#     > 2. wakeup function ends up calling task_work_add() with TWA_SIGNAL
#     > 3. task_work_add() sets the TIF_NOTIFY_SIGNAL bit by calling
#     >    set_notify_signal()
#     
#     The coredump code deliberately supports being interrupted by SIGKILL,
#     and depends upon prepare_signal to filter out all other signals.   Now
#     that signal_pending includes wake ups for TIF_NOTIFY_SIGNAL this hack
#     in dump_emitted by the coredump code no longer works.
#     
#     Make the coredump code more robust by explicitly testing for all of
#     the wakeup conditions the coredump code supports.  This prevents
#     new wakeup conditions from breaking the coredump code, as well
#     as fixing the current issue.
#     
#     The filesystem code that the coredump code uses already limits
#     itself to only aborting on fatal_signal_pending.  So it should
#     not develop surprising wake-up reasons either.
#     
#     v2: Don't remove the now unnecessary code in prepare_signal.
#     
#     Cc: stable@vger.kernel.org
#     Fixes: 12db8b690010 ("entry: Add support for TIF_NOTIFY_SIGNAL")
#     Reported-by: Olivier Langlois <olivier@trillion01.com>
#     Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux-ld --version
# < git log --format=%s --max-count=1 06af8679449d4ed282df13191fc52d5ba28ec536
# < make -s -j 24 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux-  defconfig
# < make -s -j 24 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux-  help
# make -s -j 24 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux-  olddefconfig
# make -s -j 24 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/s390-linux/bin/s390-linux-  
Completed OK
# rm -rf /kisskb/build/linus_s390-defconfig_s390x-gcc8
# Build took: 0:05:10.428125