# git rev-parse -q --verify a68a0262abdaa251e12c53715f48e698a18ef402^{commit}
a68a0262abdaa251e12c53715f48e698a18ef402
already have revision, skipping fetch
# git checkout -q -f -B kisskb a68a0262abdaa251e12c53715f48e698a18ef402
# git clean -qxdf
# < git log -1
# commit a68a0262abdaa251e12c53715f48e698a18ef402
# Author: Minchan Kim <minchan@kernel.org>
# Date:   Tue Dec 8 20:57:18 2020 -0800
# 
#     mm/madvise: remove racy mm ownership check
#     
#     Jann spotted the security hole due to race of mm ownership check.
#     
#     If the task is sharing the mm_struct but goes through execve() before
#     mm_access(), it could skip process_madvise_behavior_valid check.  That
#     makes *any advice hint* to reach into the remote process.
#     
#     This patch removes the mm ownership check.  With it, it will lose the
#     ability that local process could give *any* advice hint with vector
#     interface for some reason (e.g., performance).  Since there is no
#     concrete example in upstream yet, it would be better to remove the
#     abiliity at this moment and need to review when such new advice comes
#     up.
#     
#     Fixes: ecb8ac8b1f14 ("mm/madvise: introduce process_madvise() syscall: an external memory hinting API")
#     Reported-by: Jann Horn <jannh@google.com>
#     Suggested-by: Jann Horn <jannh@google.com>
#     Signed-off-by: Minchan Kim <minchan@kernel.org>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 a68a0262abdaa251e12c53715f48e698a18ef402
# < make -s -j 8 ARCH=powerpc O=/kisskb/build/linus_pmac32_defconfig+SMP_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  pmac32_defconfig
# Added to kconfig CONFIG_SMP=y
# < make -s -j 8 ARCH=powerpc O=/kisskb/build/linus_pmac32_defconfig+SMP_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 8 ARCH=powerpc O=/kisskb/build/linus_pmac32_defconfig+SMP_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
.config:4119:warning: override: reassigning to symbol SMP
# make -s -j 8 ARCH=powerpc O=/kisskb/build/linus_pmac32_defconfig+SMP_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  
/kisskb/src/arch/powerpc/platforms/powermac/smp.c: In function 'smp_core99_cpu_disable':
/kisskb/src/arch/powerpc/platforms/powermac/smp.c:914:2: error: implicit declaration of function 'cleanup_cpu_mmu_context' [-Werror=implicit-function-declaration]
  cleanup_cpu_mmu_context();
  ^
cc1: all warnings being treated as errors
make[4]: *** [/kisskb/src/scripts/Makefile.build:279: arch/powerpc/platforms/powermac/smp.o] Error 1
make[3]: *** [/kisskb/src/scripts/Makefile.build:496: arch/powerpc/platforms/powermac] Error 2
make[2]: *** [/kisskb/src/scripts/Makefile.build:496: arch/powerpc/platforms] Error 2
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [/kisskb/src/Makefile:1805: arch/powerpc] Error 2
make[1]: *** Waiting for unfinished jobs....
make: *** [Makefile:185: __sub-make] Error 2
Command 'make -s -j 8 ARCH=powerpc O=/kisskb/build/linus_pmac32_defconfig+SMP_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  ' returned non-zero exit status 2
# rm -rf /kisskb/build/linus_pmac32_defconfig+SMP_powerpc-gcc4.9
# Build took: 0:01:00.185358