FYI, we noticed the following commit (built with gcc-7): commit: 661ccd4df38fdcddfeb1f314ac1a1de6c947c3f9 ("[RFC PATCH] SUNRPC: Harden the cache 'channel' interface to only allow legitimate daemons") url: https://github.com/0day-ci/linux/commits/Dave-Wysochanski/SUNRPC-Harden-t... base: git://linux-nfs.org/~bfields/linux.git nfsd-next in testcase: ltp with following parameters: disk: 1HDD fs: btrfs test: fs-02 test-description: The LTP testsuite contains a collection of tools for testing the Linux kernel and related features. test-url: http://linux-test-project.github.io/ on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G 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 <rong.a.chen(a)intel.com&gt; <<<test_start>>> tag=proc01 stime=1564252108 cmdline="proc01 -m 128" contacts="" analysis=exit <<<test_output>>> proc01 0 TINFO : /proc/sys/fs/binfmt_misc/register: is write-only. proc01 0 TINFO : /proc/sys/net/ipv6/conf/all/stable_secret: known issue: errno=EIO(5): Input/output error proc01 0 TINFO : /proc/sys/net/ipv6/conf/default/stable_secret: known issue: errno=EIO(5): Input/output error proc01 0 TINFO : /proc/sys/net/ipv6/conf/eth0/stable_secret: known issue: errno=EIO(5): Input/output error proc01 0 TINFO : /proc/sys/net/ipv6/conf/lo/stable_secret: known issue: errno=EIO(5): Input/output error proc01 0 TINFO : /proc/kmsg: known issue: errno=EAGAIN/EWOULDBLOCK(11): Resource temporarily unavailable proc01 0 TINFO : /proc/sysrq-trigger: is write-only. proc01 1 TFAIL : proc01.c:397: read failed: /proc/self/task/2597/net/rpc/auth.unix.ip/channel: errno=EIO(5): Input/output error proc01 2 TFAIL : proc01.c:397: read failed: /proc/self/task/2597/net/rpc/auth.unix.gid/channel: errno=EIO(5): Input/output error proc01 0 TINFO : /proc/self/task/2597/mem: known issue: errno=EIO(5): Input/output error proc01 0 TINFO : /proc/self/task/2597/clear_refs: is write-only. proc01 0 TINFO : /proc/self/task/2597/pagemap: reached maxmbytes (-m) proc01 3 TFAIL : proc01.c:397: read failed: /proc/self/net/rpc/auth.unix.ip/channel: errno=EIO(5): Input/output error proc01 4 TFAIL : proc01.c:397: read failed: /proc/self/net/rpc/auth.unix.gid/channel: errno=EIO(5): Input/output error proc01 0 TINFO : /proc/self/mem: known issue: errno=EIO(5): Input/output error proc01 0 TINFO : /proc/self/clear_refs: is write-only. proc01 0 TINFO : /proc/self/pagemap: reached maxmbytes (-m) proc01 5 TFAIL : proc01.c:466: readproc() failed with 4 errors. <<<execution_status>>> initiation_status="ok" duration=0 termination_type=exited termination_id=1 corefile=no cutime=7 cstime=73 <<<test_end>>> To reproduce: # build kernel cd linux cp config-5.2.0-rc2-00038-g661ccd4df38fdc .config make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage modules make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 INSTALL_MOD_PATH=<mod-install-dir> modules_install cd <mod-install-dir> 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 <bzImage> -m modules.cgz job-script # job-script is attached in this email Thanks, Rong Chen