# 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-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 aee101d7b95a03078945681dd7f7ea5e4a1e7686 # < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc85xx_defconfig+KVM_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- mpc85xx_defconfig # Added to kconfig CONFIG_PPC_E500MC=y # Added to kconfig CONFIG_VIRTUALIZATION=y # Added to kconfig CONFIG_KVM_E500MC=y # Added to kconfig # < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc85xx_defconfig+KVM_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc85xx_defconfig+KVM_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig .config:4311:warning: override: reassigning to symbol PPC_E500MC .config:4312:warning: override: reassigning to symbol VIRTUALIZATION # make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc85xx_defconfig+KVM_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- In file included from /kisskb/src/include/linux/bitops.h:33, from /kisskb/src/include/linux/kernel.h:13, from /kisskb/src/include/linux/cpumask.h:10, from /kisskb/src/include/linux/smp.h:13, from /kisskb/src/include/linux/lockdep.h:14, from /kisskb/src/include/linux/mutex.h:17, from /kisskb/src/arch/powerpc/include/asm/kvm_ppc.h:15, from /kisskb/src/arch/powerpc/kvm/e500_emulate.c:12: /kisskb/src/arch/powerpc/include/asm/bitops.h: In function 'kvmppc_core_emulate_op_e500': /kisskb/src/arch/powerpc/include/asm/bitops.h:104:3: error: asm operand 2 probably doesn't match constraints [-Werror] 104 | asm volatile ( \ | ^~~ /kisskb/src/arch/powerpc/include/asm/bitops.h:126:1: note: in expansion of macro 'DEFINE_CLROP' 126 | DEFINE_CLROP(clear_bits, "") | ^~~~~~~~~~~~ /kisskb/src/arch/powerpc/include/asm/bitops.h:104:3: error: impossible constraint in 'asm' 104 | asm volatile ( \ | ^~~ /kisskb/src/arch/powerpc/include/asm/bitops.h:126:1: note: in expansion of macro 'DEFINE_CLROP' 126 | DEFINE_CLROP(clear_bits, "") | ^~~~~~~~~~~~ cc1: all warnings being treated as errors make[3]: *** [/kisskb/src/scripts/Makefile.build:288: arch/powerpc/kvm/e500_emulate.o] Error 1 make[3]: *** Waiting for unfinished jobs.... make[2]: *** [/kisskb/src/scripts/Makefile.build:550: arch/powerpc/kvm] Error 2 make[2]: *** Waiting for unfinished jobs.... make[1]: *** [/kisskb/src/Makefile:1840: arch/powerpc] Error 2 make[1]: *** Waiting for unfinished jobs.... make: *** [Makefile:219: __sub-make] Error 2 Command 'make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc85xx_defconfig+KVM_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux- ' returned non-zero exit status 2 # rm -rf /kisskb/build/powerpc-fixes_mpc85xx_defconfig+KVM_powerpc-gcc9 # Build took: 0:01:29.247725