# git rev-parse -q --verify ea721ec55c8a4a166373978b9c8ce77374d684d6^{commit}
# git fetch -q -n -f git://gitlab.ozlabs.ibm.com/linuxppc/linux.git next-test
# git rev-parse -q --verify ea721ec55c8a4a166373978b9c8ce77374d684d6^{commit}
ea721ec55c8a4a166373978b9c8ce77374d684d6
# git checkout -q -f -B kisskb ea721ec55c8a4a166373978b9c8ce77374d684d6
# git clean -qxdf
# < git log -1
# commit ea721ec55c8a4a166373978b9c8ce77374d684d6
# Author: Jordan Niethe <jniethe5@gmail.com>
# Date:   Mon Feb 8 14:29:57 2021 +1100
# 
#     selftests/powerpc: Test for spurious kernel memory faults on radix
#     
#     Previously when mapping kernel memory on radix, no ptesync was included
#     which would periodically lead to unhandled spurious faults. Mapping
#     kernel memory is used when code patching with Strict RWX enabled.  As
#     suggested by Chris Riedl, turning ftrace on and off does a large amount
#     of code patching so is a convenient way to see this kind of fault.
#     
#     Add a selftest to try and trigger this kind of a spurious fault. It
#     tests for 30 seconds which is usually long enough for the issue to show
#     up.
#     
#     Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20210208032957.1232102-2-jniethe5@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 ea721ec55c8a4a166373978b9c8ce77374d684d6
# < make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64e_defconfig+UP_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  ppc64e_defconfig
# Added to kconfig CONFIG_SMP=n
# < make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64e_defconfig+UP_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64e_defconfig+UP_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64e_defconfig+UP_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
INFO: Uncompressed kernel (size 0xc66cf4) overlaps the address of the wrapper(0x400000)
INFO: Fixing the link_address of wrapper to (0xd00000)
Image Name:   Linux-5.11.0-rc2-gea721ec55c8a
Created:      Thu Feb 11 02:00:11 2021
Image Type:   PowerPC Linux Kernel Image (gzip compressed)
Data Size:    5002201 Bytes = 4884.96 KiB = 4.77 MiB
Load Address: 00000000
Entry Point:  00000000
Completed OK
# rm -rf /kisskb/build/powerpc-next_ppc64e_defconfig+UP_powerpc-gcc5
# Build took: 0:02:19.813332