# git rev-parse -q --verify 5a72345e6a78120368fcc841b570331b6c5a50da^{commit}
# git fetch -q -n -f git://gitlab.ozlabs.ibm.com/linuxppc/linux.git next-test
# git rev-parse -q --verify 5a72345e6a78120368fcc841b570331b6c5a50da^{commit}
5a72345e6a78120368fcc841b570331b6c5a50da
# git checkout -q -f -B kisskb 5a72345e6a78120368fcc841b570331b6c5a50da
# git clean -qxdf
# < git log -1
# commit 5a72345e6a78120368fcc841b570331b6c5a50da
# Author: Michael Ellerman <mpe@ellerman.id.au>
# Date:   Fri Feb 11 17:32:37 2022 +1100
# 
#     powerpc: Fix STACKTRACE=n build
#     
#     Our skiroot_defconfig doesn't enable FTRACE, and so doesn't get
#     STACKTRACE enabled either. That leads to a build failure since commit
#     1614b2b11fab ("arch: Make ARCH_STACKWALK independent of STACKTRACE")
#     made stacktrace.c build even when STACKTRACE=n.
#     
#       arch/powerpc/kernel/stacktrace.c: In function ‘handle_backtrace_ipi’:
#       arch/powerpc/kernel/stacktrace.c:171:2: error: implicit declaration of function ‘nmi_cpu_backtrace’
#         171 |  nmi_cpu_backtrace(regs);
#             |  ^~~~~~~~~~~~~~~~~
#       arch/powerpc/kernel/stacktrace.c: In function ‘arch_trigger_cpumask_backtrace’:
#       arch/powerpc/kernel/stacktrace.c:226:2: error: implicit declaration of function ‘nmi_trigger_cpumask_backtrace’
#         226 |  nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi);
#             |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#     
#     This happens because our headers haven't defined
#     arch_trigger_cpumask_backtrace, which causes lib/nmi_backtrace.c not to
#     build nmi_cpu_backtrace().
#     
#     The code in question doesn't actually depend on STACKTRACE=y, that was
#     just added because arch_trigger_cpumask_backtrace() lived in
#     stacktrace.c for convenience. So drop the dependency on
#     CONFIG_STACKTRACE, that causes lib/nmi_backtrace.c to build
#     nmi_cpu_backtrace() etc. and fixes the build.
#     
#     Fixes: 1614b2b11fab ("arch: Make ARCH_STACKWALK independent of STACKTRACE")
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20220212111349.2806972-1-mpe@ellerman.id.au
# < /opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-gcc --version
# < /opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-ld --version
# < git log --format=%s --max-count=1 5a72345e6a78120368fcc841b570331b6c5a50da
# < make -s -j 80 ARCH=microblaze O=/kisskb/build/powerpc-next_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-  mmu_defconfig
# < make -s -j 80 ARCH=microblaze O=/kisskb/build/powerpc-next_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-  help
# make -s -j 80 ARCH=microblaze O=/kisskb/build/powerpc-next_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-  olddefconfig
# make -s -j 80 ARCH=microblaze O=/kisskb/build/powerpc-next_mmu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-  
Kernel: arch/microblaze/boot/linux.bin is ready  (#1)
Completed OK
# rm -rf /kisskb/build/powerpc-next_mmu_defconfig_microblaze
# Build took: 0:01:11.779938