# git rev-parse -q --verify d5c243989fb0cb03c74d7340daca3b819f706ee7^{commit} d5c243989fb0cb03c74d7340daca3b819f706ee7 already have revision, skipping fetch # git checkout -q -f -B kisskb d5c243989fb0cb03c74d7340daca3b819f706ee7 # git clean -qxdf # < git log -1 # commit d5c243989fb0cb03c74d7340daca3b819f706ee7 # Author: Christophe Leroy # Date: Mon Dec 21 06:18:03 2020 +0000 # # powerpc/32: Fix vmap stack - Properly set r1 before activating MMU on syscall too # # We need r1 to be properly set before activating MMU, otherwise any new # exception taken while saving registers into the stack in syscall # prologs will use the user stack, which is wrong and will even lockup # or crash when KUAP is selected. # # Do that by switching the meaning of r11 and r1 until we have saved r1 # to the stack: copy r1 into r11 and setup the new stack pointer in r1. # To avoid complicating and impacting all generic and specific prolog # code (and more), copy back r1 into r11 once r11 is save onto # the stack. # # We could get rid of copying r1 back and forth at the cost of rewriting # everything to use r1 instead of r11 all the way when CONFIG_VMAP_STACK # is set, but the effort is probably not worth it for now. # # Fixes: da7bb43ab9da ("powerpc/32: Fix vmap stack - Properly set r1 before activating MMU") # Cc: stable@vger.kernel.org # v5.10+ # Signed-off-by: Christophe Leroy # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/a3d819d5c348cee9783a311d5d3f3ba9b48fd219.1608531452.git.christophe.leroy@csgroup.eu # < /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 d5c243989fb0cb03c74d7340daca3b819f706ee7 # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_83xx_mpc837x_mds_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- 83xx/mpc837x_mds_defconfig # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_83xx_mpc837x_mds_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- INFO: Uncompressed kernel (size 0x706724) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x800000) Image Name: Linux-5.10.0-gd5c243989fb0 Created: Tue Dec 22 00:26:10 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 3109342 Bytes = 3036.47 KiB = 2.97 MiB Load Address: 00000000 Entry Point: 00000000 Completed OK # rm -rf /kisskb/build/powerpc-fixes_83xx_mpc837x_mds_defconfig_powerpc-gcc5 # Build took: 0:00:30.578643