# git rev-parse -q --verify 8734b41b3efe0fc6082c1937b0e88556c396dc96^{commit} 8734b41b3efe0fc6082c1937b0e88556c396dc96 already have revision, skipping fetch # git checkout -q -f -B kisskb 8734b41b3efe0fc6082c1937b0e88556c396dc96 # git clean -qxdf # < git log -1 # commit 8734b41b3efe0fc6082c1937b0e88556c396dc96 # Author: Russell Currey # Date: Tue Nov 23 18:15:20 2021 +1000 # # powerpc/module_64: Fix livepatching for RO modules # # Livepatching a loaded module involves applying relocations through # apply_relocate_add(), which attempts to write to read-only memory when # CONFIG_STRICT_MODULE_RWX=y. Work around this by performing these # writes through the text poke area by using patch_instruction(). # # R_PPC_REL24 is the only relocation type generated by the kpatch-build # userspace tool or klp-convert kernel tree that I observed applying a # relocation to a post-init module. # # A more comprehensive solution is planned, but using patch_instruction() # for R_PPC_REL24 on should serve as a sufficient fix. # # This does have a performance impact, I observed ~15% overhead in # module_load() on POWER8 bare metal with checksum verification off. # # Fixes: c35717c71e98 ("powerpc: Set ARCH_HAS_STRICT_MODULE_RWX") # Cc: stable@vger.kernel.org # v5.14+ # Reported-by: Joe Lawrence # Signed-off-by: Russell Currey # Tested-by: Joe Lawrence # [mpe: Check return codes from patch_instruction()] # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20211214121248.777249-1-mpe@ellerman.id.au # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 8734b41b3efe0fc6082c1937b0e88556c396dc96 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig+NO_MEMORY_HOTPLUG_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- pseries_defconfig # Added to kconfig CONFIG_MEMORY_HOTPLUG=n # Added to kconfig CONFIG_MEMORY_HOTREMOVE=n # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig+NO_MEMORY_HOTPLUG_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig+NO_MEMORY_HOTPLUG_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig+NO_MEMORY_HOTPLUG_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- :1559:2: warning: #warning syscall futex_waitv not implemented [-Wcpp] Completed OK # rm -rf /kisskb/build/powerpc-fixes_pseries_defconfig+NO_MEMORY_HOTPLUG_powerpc-gcc11 # Build took: 0:04:14.051736