# git rev-parse -q --verify a9f675f950a07d5c1dbcbb97aabac56f5ed085e3^{commit}
a9f675f950a07d5c1dbcbb97aabac56f5ed085e3
already have revision, skipping fetch
# git checkout -q -f -B kisskb a9f675f950a07d5c1dbcbb97aabac56f5ed085e3
# git clean -qxdf
# < git log -1
# commit a9f675f950a07d5c1dbcbb97aabac56f5ed085e3
# Author: Milton Miller <miltonm@us.ibm.com>
# Date:   Thu Jul 16 09:37:04 2020 +1000
# 
#     powerpc/vdso: Fix vdso cpu truncation
#     
#     The code in vdso_cpu_init that exposes the cpu and numa node to
#     userspace via SPRG_VDSO incorrctly masks the cpu to 12 bits. This means
#     that any kernel running on a box with more than 4096 threads (NR_CPUS
#     advertises a limit of of 8192 cpus) would expose userspace to two cpu
#     contexts running at the same time with the same cpu number.
#     
#     Note: I'm not aware of any distro shipping a kernel with support for more
#     than 4096 threads today, nor of any system image that currently exceeds
#     4096 threads. Found via code browsing.
#     
#     Fixes: 18ad51dd342a7eb09dbcd059d0b451b616d4dafc ("powerpc: Add VDSO version of getcpu")
#     Signed-off-by: Milton Miller <miltonm@us.ibm.com>
#     Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20200715233704.1352257-1-anton@ozlabs.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 a9f675f950a07d5c1dbcbb97aabac56f5ed085e3
# < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  randconfig
KCONFIG_SEED=0x791FC324
# Added to kconfig CONFIG_STANDALONE=y
# Added to kconfig CONFIG_BUILD_DOCSRC=n
# Added to kconfig CONFIG_MODULE_SIG=n
# Added to kconfig CONFIG_CPU_BIG_ENDIAN=y
# Added to kconfig CONFIG_PPC64=y
# Added to kconfig CONFIG_PPC_DISABLE_WERROR=y
# Added to kconfig CONFIG_SECTION_MISMATCH_WARN_ONLY=y
# Added to kconfig CONFIG_PREVENT_FIRMWARE_BUILD=y
# Added to kconfig CONFIG_CC_STACKPROTECTOR_STRONG=n
# Added to kconfig CONFIG_GCC_PLUGINS=n
# Added to kconfig CONFIG_LD_HEAD_STUB_CATCH=y
# Added to kconfig CONFIG_TRIM_UNUSED_KSYMS=n
# Added to kconfig CONFIG_UBSAN=n
# < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
.config:4281:warning: override: reassigning to symbol PPC_DISABLE_WERROR
.config:4283:warning: override: reassigning to symbol PREVENT_FIRMWARE_BUILD
.config:4286:warning: override: reassigning to symbol LD_HEAD_STUB_CATCH
# make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  
/kisskb/src/arch/powerpc/platforms/cell/spufs/sched.c:1061:12: warning: 'show_spu_loadavg' defined but not used [-Wunused-function]
 static int show_spu_loadavg(struct seq_file *s, void *private)
            ^
/kisskb/src/arch/powerpc/kernel/eeh.c:1707:12: warning: 'proc_eeh_show' defined but not used [-Wunused-function]
 static int proc_eeh_show(struct seq_file *m, void *v)
            ^
Segmentation fault (core dumped)
make[1]: *** [/kisskb/src/Makefile:1139: vmlinux] Error 139
make: *** [Makefile:185: __sub-make] Error 2
Command 'make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_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/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.9
# Build took: 0:04:06.208408