# git rev-parse -q --verify 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3^{commit} 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 already have revision, skipping fetch # git checkout -q -f -B kisskb 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 # git clean -qxdf # < git log -1 # commit 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 # Author: Michael Neuling # Date: Fri Sep 14 11:14:11 2018 +1000 # # powerpc: Avoid code patching freed init sections # # This stops us from doing code patching in init sections after they've # been freed. # # In this chain: # kvm_guest_init() -> # kvm_use_magic_page() -> # fault_in_pages_readable() -> # __get_user() -> # __get_user_nocheck() -> # barrier_nospec(); # # We have a code patching location at barrier_nospec() and # kvm_guest_init() is an init function. This whole chain gets inlined, # so when we free the init section (hence kvm_guest_init()), this code # goes away and hence should no longer be patched. # # We seen this as userspace memory corruption when using a memory # checker while doing partition migration testing on powervm (this # starts the code patching post migration via # /sys/kernel/mobility/migration). In theory, it could also happen when # using /sys/kernel/debug/powerpc/barrier_nospec. # # Cc: stable@vger.kernel.org # 4.13+ # Signed-off-by: Michael Neuling # Reviewed-by: Nicholas Piggin # Reviewed-by: Christophe Leroy # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < git log --format=%s --max-count=1 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 # < make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_44x_iss476-smp_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- 44x/iss476-smp_defconfig WARNING: unmet direct dependencies detected for HOTPLUG_CPU Depends on [n]: SMP [=y] && (PPC_PSERIES [=n] || PPC_PMAC [=n] || PPC_POWERNV [=n] || FSL_SOC_BOOKE [=n]) Selected by [y]: - PM_SLEEP_SMP [=y] && SMP [=y] && (ARCH_SUSPEND_POSSIBLE [=y] || ARCH_HIBERNATION_POSSIBLE [=y]) && PM_SLEEP [=y] WARNING: unmet direct dependencies detected for HOTPLUG_CPU Depends on [n]: SMP [=y] && (PPC_PSERIES [=n] || PPC_PMAC [=n] || PPC_POWERNV [=n] || FSL_SOC_BOOKE [=n]) Selected by [y]: - PM_SLEEP_SMP [=y] && SMP [=y] && (ARCH_SUSPEND_POSSIBLE [=y] || ARCH_HIBERNATION_POSSIBLE [=y]) && PM_SLEEP [=y] WARNING: unmet direct dependencies detected for HOTPLUG_CPU Depends on [n]: SMP [=y] && (PPC_PSERIES [=n] || PPC_PMAC [=n] || PPC_POWERNV [=n] || FSL_SOC_BOOKE [=n]) Selected by [y]: - PM_SLEEP_SMP [=y] && SMP [=y] && (ARCH_SUSPEND_POSSIBLE [=y] || ARCH_HIBERNATION_POSSIBLE [=y]) && PM_SLEEP [=y] # make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_44x_iss476-smp_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- INFO: Uncompressed kernel (size 0x5d92ac) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5d92ac) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Completed OK # rm -rf /kisskb/build/powerpc-fixes_44x_iss476-smp_defconfig_powerpc-gcc5 # Build took: 0:00:50.034884