# git rev-parse -q --verify 7efd182a94e167c2cb0187009ae1fffa8c485e97^{commit}
7efd182a94e167c2cb0187009ae1fffa8c485e97
already have revision, skipping fetch
# git checkout -q -f -B kisskb 7efd182a94e167c2cb0187009ae1fffa8c485e97
# git clean -qxdf
# < git log -1
# commit 7efd182a94e167c2cb0187009ae1fffa8c485e97
# Author: Christophe Leroy <christophe.leroy@csgroup.eu>
# Date:   Wed Oct 13 17:09:54 2021 +0200
# 
#     lkdtm: Add a test for function descriptors protection
#     
#     Add WRITE_OPD to check that you can't modify function
#     descriptors.
#     
#     Gives the following result when function descriptors are
#     not protected:
#     
#             lkdtm: Performing direct entry WRITE_OPD
#             lkdtm: attempting bad 16 bytes write at c00000000269b358
#             lkdtm: FAIL: survived bad write
#             lkdtm: do_nothing was hijacked!
#     
#     Looks like a standard compiler barrier() is not enough to force
#     GCC to use the modified function descriptor. Had to add a fake empty
#     inline assembly to force GCC to reload the function descriptor.
#     
#     Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
#     Acked-by: Kees Cook <keescook@chromium.org>
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux-ld --version
# < git log --format=%s --max-count=1 7efd182a94e167c2cb0187009ae1fffa8c485e97
# < make -s -j 80 ARCH=arm64 O=/kisskb/build/chleroy_arm64-defconfig_arm64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux-  defconfig
# < make -s -j 80 ARCH=arm64 O=/kisskb/build/chleroy_arm64-defconfig_arm64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux-  help
# make -s -j 80 ARCH=arm64 O=/kisskb/build/chleroy_arm64-defconfig_arm64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux-  olddefconfig
# make -s -j 80 ARCH=arm64 O=/kisskb/build/chleroy_arm64-defconfig_arm64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux-  
Completed OK
# rm -rf /kisskb/build/chleroy_arm64-defconfig_arm64-gcc11
# Build took: 0:08:14.957822