# git rev-parse -q --verify aee101d7b95a03078945681dd7f7ea5e4a1e7686^{commit} aee101d7b95a03078945681dd7f7ea5e4a1e7686 already have revision, skipping fetch # git checkout -q -f -B kisskb aee101d7b95a03078945681dd7f7ea5e4a1e7686 # git clean -qxdf # < git log -1 # commit aee101d7b95a03078945681dd7f7ea5e4a1e7686 # Author: Nicholas Piggin # Date: Mon Jan 17 23:44:03 2022 +1000 # # powerpc/64s: Mask SRR0 before checking against the masked NIP # # Commit 314f6c23dd8d ("powerpc/64s: Mask NIP before checking against # SRR0") masked off the low 2 bits of the NIP value in the interrupt # stack frame in case they are non-zero and mis-compare against a SRR0 # register value of a CPU which always reads back 0 from the 2 low bits # which are reserved. # # This now causes the opposite problem that an implementation which does # implement those bits in SRR0 will mis-compare against the masked NIP # value in which they have been cleared. QEMU is one such implementation, # and this is allowed by the architecture. # # This can be triggered by sigfuz by setting low bits of PT_NIP in the # signal context. # # Fix this for now by masking the SRR0 bits as well. Cleaner is probably # to sanitise these values before putting them in registers or stack, but # this is the quick and backportable fix. # # Fixes: 314f6c23dd8d ("powerpc/64s: Mask NIP before checking against SRR0") # Signed-off-by: Nicholas Piggin # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20220117134403.2995059-1-npiggin@gmail.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 aee101d7b95a03078945681dd7f7ea5e4a1e7686 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet32_smp_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- corenet32_smp_defconfig # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet32_smp_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet32_smp_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet32_smp_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_corenet32_smp_defconfig_powerpc-gcc5 # Build took: 0:02:23.751936