# git rev-parse -q --verify 0460534b532e5518c657c7d6492b9337d975eaa3^{commit}
0460534b532e5518c657c7d6492b9337d975eaa3
already have revision, skipping fetch
# git checkout -q -f -B kisskb 0460534b532e5518c657c7d6492b9337d975eaa3
# git clean -qxdf
# < git log -1
# commit 0460534b532e5518c657c7d6492b9337d975eaa3
# Author: Vaibhav Jain <vaibhav@linux.ibm.com>
# Date:   Mon Sep 7 16:35:40 2020 +0530
# 
#     powerpc/papr_scm: Limit the readability of 'perf_stats' sysfs attribute
#     
#     The newly introduced 'perf_stats' attribute uses the default access
#     mode of 0444, allowing non-root users to access performance stats of
#     an nvdimm and potentially force the kernel into issuing a large number
#     of expensive hypercalls. Since the information exposed by this
#     attribute cannot be cached it is better to ward off access to this
#     attribute from users who don't need to access to these performance
#     statistics.
#     
#     Hence update the access mode of 'perf_stats' attribute to be only
#     readable by root users.
#     
#     Fixes: 2d02bf835e57 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
#     Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
#     Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
#     Reviewed-by: Ira Weiny <ira.weiny@intel.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20200907110540.21349-1-vaibhav@linux.ibm.com
# < /opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 0460534b532e5518c657c7d6492b9337d975eaa3
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_powernv_defconfig+NO_PERF_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  powernv_defconfig
# Added to kconfig CONFIG_PERF_EVENTS=n
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_powernv_defconfig+NO_PERF_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_powernv_defconfig+NO_PERF_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_powernv_defconfig+NO_PERF_powerpc-gcc9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-9.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_powernv_defconfig+NO_PERF_powerpc-gcc9
# Build took: 0:03:34.119599