# git rev-parse -q --verify fe673d3f5bf1fc50cdc4b754831db91a2ec10126^{commit} # git fetch -q -n -f git://fs.ozlabs.ibm.com/kernel/linus master # git rev-parse -q --verify fe673d3f5bf1fc50cdc4b754831db91a2ec10126^{commit} fe673d3f5bf1fc50cdc4b754831db91a2ec10126 # git checkout -q -f -B kisskb fe673d3f5bf1fc50cdc4b754831db91a2ec10126 # git clean -qxdf # < git log -1 # commit fe673d3f5bf1fc50cdc4b754831db91a2ec10126 # Author: Linus Torvalds # 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 # 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 # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux-ld --version # < git log --format=%s --max-count=1 fe673d3f5bf1fc50cdc4b754831db91a2ec10126 # < make -s -j 80 ARCH=x86_64 O=/kisskb/build/linus_x86_64-allnoconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux- allnoconfig # < make -s -j 80 ARCH=x86_64 O=/kisskb/build/linus_x86_64-allnoconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux- help # make -s -j 80 ARCH=x86_64 O=/kisskb/build/linus_x86_64-allnoconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux- olddefconfig # make -s -j 80 ARCH=x86_64 O=/kisskb/build/linus_x86_64-allnoconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/x86_64-linux/bin/x86_64-linux- Completed OK # rm -rf /kisskb/build/linus_x86_64-allnoconfig_x86_64-gcc8 # Build took: 0:01:03.143827