FYI, we noticed the following commit (built with gcc-7): commit: 71ab3fd618a57999aca56f35c8a68193737ef5a0 ("fold into pmtu run_test refactor") https://github.com/dsahern/linux 5.2-next-nh-v3 in testcase: kernel_selftests with following parameters: group: kselftests-02 test-description: The kernel contains a set of "self tests" under the tools/testing/selftests/ directory. These are intended to be small unit tests to exercise individual code paths in the kernel. test-url: https://www.kernel.org/doc/Documentation/kselftest.txt on test machine: qemu-system-x86_64 -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 <rong.a.chen(a)intel.com&gt; KERNEL SELFTESTS: linux_headers_dir is /usr/src/linux-headers-x86_64-rhel-7.6-71ab3fd618a57999aca56f35c8a68193737ef5a0 media_tests test: not in Makefile 2019-05-24 13:31:27 make TARGETS=media_tests make[1]: Entering directory '/usr/src/perf_selftests-x86_64-rhel-7.6-71ab3fd618a57999aca56f35c8a68193737ef5a0/tools/testing/selftests/media_tests' gcc -I../ -I../../../../usr/include/ media_device_test.c -o /usr/src/perf_selftests-x86_64-rhel-7.6-71ab3fd618a57999aca56f35c8a68193737ef5a0/tools/testing/selftests/media_tests/media_device_test gcc -I../ -I../../../../usr/include/ media_device_open.c -o /usr/src/perf_selftests-x86_64-rhel-7.6-71ab3fd618a57999aca56f35c8a68193737ef5a0/tools/testing/selftests/media_tests/media_device_open gcc -I../ -I../../../../usr/include/ video_device_test.c -o /usr/src/perf_selftests-x86_64-rhel-7.6-71ab3fd618a57999aca56f35c8a68193737ef5a0/tools/testing/selftests/media_tests/video_device_test make[1]: Leaving directory '/usr/src/perf_selftests-x86_64-rhel-7.6-71ab3fd618a57999aca56f35c8a68193737ef5a0/tools/testing/selftests/media_tests' ignored_by_lkp media_tests test selftests: net: fib-onlink-tests.sh ======================================== ######################################## Configuring interfaces RTNETLINK answers: File exists not ok 1..14 selftests: net: fib-onlink-tests.sh [FAIL] selftests: net: pmtu.sh ======================================== TEST: ipv4: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. RTNETLINK answers: Network is unreachable TEST: ipv4: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding MTU TEST: ipv6: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. RTNETLINK answers: Network is unreachable TEST: ipv6: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding MTU TEST: IPv4 over vxlan4: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv4 over vxlan4: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on vxlan interface TEST: IPv6 over vxlan4: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv6 over vxlan4: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on vxlan interface TEST: IPv4 over vxlan6: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv4 over vxlan6: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on vxlan interface TEST: IPv6 over vxlan6: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv6 over vxlan6: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on vxlan interface TEST: IPv4 over geneve4: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv4 over geneve4: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on geneve interface TEST: IPv6 over geneve4: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv6 over geneve4: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on geneve interface TEST: IPv4 over geneve6: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv4 over geneve6: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on geneve interface TEST: IPv6 over geneve6: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv6 over geneve6: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on geneve interface TEST: IPv4 over fou4: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv4 over fou4: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on fou interface TEST: IPv6 over fou4: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv6 over fou4: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on fou interface TEST: IPv4 over fou6: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv4 over fou6: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on fou interface TEST: IPv6 over fou6: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv6 over fou6: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on fou interface TEST: IPv4 over gue4: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv4 over gue4: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on gue interface TEST: IPv6 over gue4: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv6 over gue4: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on gue interface TEST: IPv4 over gue6: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv4 over gue6: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on gue interface TEST: IPv6 over gue6: PMTU exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: IPv6 over gue6: PMTU exceptions - nexthop objects [FAIL] PMTU exception wasn't created after exceeding link layer MTU on gue interface xfrm6 not supported TEST: vti6: PMTU exceptions [SKIP] xfrm6 not supported TEST: vti6: PMTU exceptions - nexthop objects [SKIP] xfrm4 not supported TEST: vti4: PMTU exceptions [SKIP] xfrm4 not supported TEST: vti4: PMTU exceptions - nexthop objects [SKIP] TEST: vti4: default MTU assignment [ OK ] TEST: vti4: default MTU assignment - nexthop objects [ OK ] TEST: vti6: default MTU assignment [ OK ] TEST: vti6: default MTU assignment - nexthop objects [ OK ] TEST: vti4: MTU setting on link creation [ OK ] TEST: vti4: MTU setting on link creation - nexthop objects [ OK ] TEST: vti6: MTU setting on link creation [ OK ] TEST: vti6: MTU setting on link creation - nexthop objects [ OK ] TEST: vti6: MTU changes on link changes [ OK ] TEST: vti6: MTU changes on link changes - nexthop objects [ OK ] TEST: ipv4: cleanup of cached exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: ipv4: cleanup of cached exceptions - nexthop objects [ OK ] TEST: ipv6: cleanup of cached exceptions [ OK ] new routing Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Object "nexthop" is unknown, try "ip help". Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. Error: either "to" is duplicate, or "nhid" is a garbage. TEST: ipv6: cleanup of cached exceptions - nexthop objects [ OK ] not ok 1..15 selftests: net: pmtu.sh [FAIL] To reproduce: # build kernel cd linux cp config-5.1.0-rc7-02038-g71ab3fd .config make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 prepare make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 modules_prepare make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 SHELL=/bin/bash make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 bzImage git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email Thanks, Rong Chen