# git rev-parse -q --verify fe673d3f5bf1fc50cdc4b754831db91a2ec10126^{commit}
fe673d3f5bf1fc50cdc4b754831db91a2ec10126
already have revision, skipping fetch
# git checkout -q -f -B kisskb fe673d3f5bf1fc50cdc4b754831db91a2ec10126
# git clean -qxdf
# < git log -1
# commit fe673d3f5bf1fc50cdc4b754831db91a2ec10126
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Tue Mar 8 11:55:48 2022 -0800
# 
#     mm: gup: make fault_in_safe_writeable() use fixup_user_fault()
#     
#     Instead of using GUP, make fault_in_safe_writeable() actually force a
#     'handle_mm_fault()' using the same fixup_user_fault() machinery that
#     futexes already use.
#     
#     Using the GUP machinery meant that fault_in_safe_writeable() did not do
#     everything that a real fault would do, ranging from not auto-expanding
#     the stack segment, to not updating accessed or dirty flags in the page
#     tables (GUP sets those flags on the pages themselves).
#     
#     The latter causes problems on architectures (like s390) that do accessed
#     bit handling in software, which meant that fault_in_safe_writeable()
#     didn't actually do all the fault handling it needed to, and trying to
#     access the user address afterwards would still cause faults.
#     
#     Reported-and-tested-by: Andreas Gruenbacher <agruenba@redhat.com>
#     Fixes: cdd591fc86e3 ("iov_iter: Introduce fault_in_iov_iter_writeable")
#     Link: https://lore.kernel.org/all/CAHc6FU5nP+nziNGG0JAF1FUx-GV7kKFvM7aZuU_XD2_1v4vnvg@mail.gmail.com/
#     Acked-by: David Hildenbrand <david@redhat.com>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux-ld --version
# < git log --format=%s --max-count=1 fe673d3f5bf1fc50cdc4b754831db91a2ec10126
# < make -s -j 48 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux-  allmodconfig
# < make -s -j 48 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux-  help
# make -s -j 48 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux-  olddefconfig
# make -s -j 48 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux-  
Completed OK
# rm -rf /kisskb/build/linus_arm64-allmodconfig_arm64-gcc8
# Build took: 0:31:23.702777