Greeting, FYI, we noticed the following commit (built with gcc-9): commit: 56348560d495d2501e87db559a61de717cd3ab02 ("debugfs: do not attempt to create a new file before the filesystem is initalized") https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master in testcase: boot on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 4G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 22.678378][ T1] UBI error: cannot create "ubi" debugfs directory, error -2 [ 22.679890][ T1] UBI error: cannot initialize UBI, error -2 To reproduce: # build kernel cd linux cp config-5.11.0-rc5-00034-g56348560d495 .config make HOSTCC=gcc-9 CC=gcc-9 ARCH=i386 olddefconfig prepare modules_prepare bzImage modules make HOSTCC=gcc-9 CC=gcc-9 ARCH=i386 INSTALL_MOD_PATH= modules_install cd find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k -m modules.cgz job-script # job-script is attached in this email # if come across any failure that blocks the test, # please remove ~/.lkp and /lkp dir to run from a clean state. --- 0DAY/LKP+ Test Infrastructure Open Source Technology Center https://lists.01.org/hyperkitty/list/lkp@lists.01.org Intel Corporation Thanks, Oliver Sang