# git rev-parse -q --verify b49f9d9b0e428909796b4a7e7f1049f489859e0f^{commit} b49f9d9b0e428909796b4a7e7f1049f489859e0f already have revision, skipping fetch # git checkout -q -f -B kisskb b49f9d9b0e428909796b4a7e7f1049f489859e0f # git clean -qxdf # < git log -1 # commit b49f9d9b0e428909796b4a7e7f1049f489859e0f # Author: Naveen N. Rao # Date: Wed May 19 16:17:17 2021 +0530 # # powerpc/kprobes: Fix validation of prefixed instructions across page boundary # # When checking if the probed instruction is the suffix of a prefixed # instruction, we access the instruction at the previous word. If the # probed instruction is the very first word of a module, we can end up # trying to access an invalid page. # # Fix this by skipping the check for all instructions at the beginning of # a page. Prefixed instructions cannot cross a 64-byte boundary and as # such, we don't expect to encounter a suffix as the very first word in a # page for kernel text. Even if there are prefixed instructions crossing # a page boundary (from a module, for instance), the instruction will be # illegal, so preventing probing on the suffix of such prefix instructions # isn't worthwhile. # # Fixes: b4657f7650ba ("powerpc/kprobes: Don't allow breakpoints on suffixes") # Cc: stable@vger.kernel.org # v5.8+ # Reported-by: Christophe Leroy # Signed-off-by: Naveen N. Rao # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/0df9a032a05576a2fa8e97d1b769af2ff0eafbd6.1621416666.git.naveen.n.rao@linux.vnet.ibm.com # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 b49f9d9b0e428909796b4a7e7f1049f489859e0f # < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- pseries_defconfig # < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- Completed OK # rm -rf /kisskb/build/powerpc-fixes_pseries_defconfig_powerpc-gcc5 # Build took: 0:03:58.457955