# git rev-parse -q --verify f5b7769eb0400ec5217a47e41148a9f816ca1f9f^{commit}
f5b7769eb0400ec5217a47e41148a9f816ca1f9f
already have revision, skipping fetch
# git checkout -q -f -B kisskb f5b7769eb0400ec5217a47e41148a9f816ca1f9f
# git clean -qxdf
# < git log -1
# commit f5b7769eb0400ec5217a47e41148a9f816ca1f9f
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Tue Jun 12 20:52:16 2018 -0700
# 
#     Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"
#     
#     This reverts commit 95cde3c59966f6371b6bcd9e4e2da2ba64ee9775.
#     
#     The commit had good intentions, but it breaks kvm-tool and qemu-kvm.
#     
#     With it in place, "lkvm run" just fails with
#     
#       Error: KVM_CREATE_VM ioctl
#       Warning: Failed init: kvm__init
#     
#     which isn't a wonderful error message, but bisection pinpointed the
#     problematic commit.
#     
#     The problem is almost certainly due to the special kvm debugfs entries
#     created dynamically by kvm under /sys/kernel/debug/kvm/.  See
#     kvm_create_vm_debugfs()
#     
#     Bisected-and-reported-by: Linus Torvalds <torvalds@linux-foundation.org>
#     Cc: Wanpeng Li <kernellwp@gmail.com>
#     Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
#     Cc: Thomas Richter <tmricht@linux.ibm.com>
#     Cc: Kees Cook <keescook@chromium.org>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/gcc-5.2.0-nolibc/powerpc64le-linux/bin/powerpc64le-linux-gcc --version
# < git log --format=%s --max-count=1 f5b7769eb0400ec5217a47e41148a9f816ca1f9f
# < make -s -j 10 ARCH=powerpc O=/kisskb/build/linus_powernv_defconfig+THIN_ppc64le CROSS_COMPILE=/opt/cross/kisskb/gcc-5.2.0-nolibc/powerpc64le-linux/bin/powerpc64le-linux-  powernv_defconfig
# Added to kconfig CONFIG_USE_THIN_ARCHIVES=y
# yes \n | make -s -j 10 ARCH=powerpc O=/kisskb/build/linus_powernv_defconfig+THIN_ppc64le CROSS_COMPILE=/opt/cross/kisskb/gcc-5.2.0-nolibc/powerpc64le-linux/bin/powerpc64le-linux-  oldconfig
yes: standard output: Broken pipe
yes: write error
# make -s -j 10 ARCH=powerpc O=/kisskb/build/linus_powernv_defconfig+THIN_ppc64le CROSS_COMPILE=/opt/cross/kisskb/gcc-5.2.0-nolibc/powerpc64le-linux/bin/powerpc64le-linux-  
/kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter.
<stdin>:1332:2: warning: #warning syscall io_pgetevents not implemented [-Wcpp]
/kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter.
WARNING: modpost: Found 2 section mismatch(es).
To see full details build your kernel with:
'make CONFIG_DEBUG_SECTION_MISMATCH=y'
Completed OK
# rm -rf /kisskb/build/linus_powernv_defconfig+THIN_ppc64le
# Build took: 0:03:10.018750