# git rev-parse -q --verify a66de5283e16602b74658289360505ceeb308c90^{commit}
a66de5283e16602b74658289360505ceeb308c90
already have revision, skipping fetch
# git checkout -q -f -B kisskb a66de5283e16602b74658289360505ceeb308c90
# git clean -qxdf
# < git log -1
# commit a66de5283e16602b74658289360505ceeb308c90
# Author: Michael Ellerman <mpe@ellerman.id.au>
# Date:   Wed Sep 7 09:37:17 2022 +1000
# 
#     powerpc/pseries: Fix plpks crash on non-pseries
#     
#     As reported[1] by Nathan, the recently added plpks driver will crash if
#     it's built into the kernel and booted on a non-pseries machine, eg
#     powernv:
#     
#       kernel BUG at arch/powerpc/kernel/syscall.c:39!
#       Oops: Exception in kernel mode, sig: 5 [#1]
#       LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV
#       ...
#       NIP system_call_exception+0x90/0x3d0
#       LR  system_call_common+0xec/0x250
#       Call Trace:
#         0xc0000000035c3e10 (unreliable)
#         system_call_common+0xec/0x250
#       --- interrupt: c00 at plpar_hcall+0x38/0x60
#       NIP:  c0000000000e4300 LR: c00000000202945c CTR: 0000000000000000
#       REGS: c0000000035c3e80 TRAP: 0c00   Not tainted  (6.0.0-rc4)
#       MSR:  9000000002009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE>  CR: 28000284  XER: 00000000
#       ...
#       NIP plpar_hcall+0x38/0x60
#       LR  pseries_plpks_init+0x64/0x23c
#       --- interrupt: c00
#     
#     On powernv Linux is the hypervisor, so a hypercall just ends up going to
#     the syscall path, which BUGs if the syscall (hypercall) didn't come from
#     userspace.
#     
#     The fix is simply to not probe the plpks driver on non-pseries machines.
#     
#     [1] https://lore.kernel.org/linuxppc-dev/Yxe06fbq18Wv9y3W@dev-arch.thelio-3990X/
#     
#     Fixes: 2454a7af0f2a ("powerpc/pseries: define driver for Platform KeyStore")
#     Reported-by: Nathan Chancellor <nathan@kernel.org>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Tested-by: Dan Horák <dan@danny.cz>
#     Reviewed-by: Dan Horák <dan@danny.cz>
#     Tested-by: Nathan Chancellor <nathan@kernel.org>
#     Link: https://lore.kernel.org/r/20220907065038.1604504-1-mpe@ellerman.id.au
# < /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 a66de5283e16602b74658289360505ceeb308c90
# < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_tqm8548_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  85xx/tqm8548_defconfig
# < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_tqm8548_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_tqm8548_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_tqm8548_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_85xx_tqm8548_defconfig_powerpc-gcc5
# Build took: 0:00:33.709874