FYI, we noticed the following commit (built with gcc-7): commit: f8bf55f05f7d665fdf5942ceb28a82089ddad44a ("mm/debug: add tests validating architecture page table helpers") https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master in testcase: boot 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): +-------------------------------------------+------------+------------+ | | bf99016ea0 | f8bf55f05f | +-------------------------------------------+------------+------------+ | boot_successes | 20 | 0 | | boot_failures | 0 | 20 | | BUG:non-zero_pgtables_bytes_on_freeing_mm | 0 | 18 | | BUG:kernel_hang_in_boot_stage | 0 | 1 | | BUG:workqueue_lockup-pool | 0 | 1 | +-------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 7.050643] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest0/status [ 7.051641] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest0/status [ 7.054849] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest0/status [ 7.054850] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest1/status [ 7.056452] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest1/status [ 7.059482] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest1/status [ 7.059483] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest2/status [ 7.076240] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest2/status [ 7.082878] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest2/status [ 7.082881] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest3/status [ 7.085979] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest3/status [ 7.093291] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest3/status [ 7.094066] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest5/status [ 7.096582] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest5/status [ 7.102576] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest5/status [ 7.102599] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest6/status [ 7.107367] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest6/status [ 7.113918] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest6/status [ 7.113920] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest7/status [ 7.117058] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest7/status [ 7.124533] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest7/status [ 7.125013] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/status [ 7.127918] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/status [ 7.134354] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/status [ 7.134357] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/property-foo [ 7.137419] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/property-foo [ 7.143157] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/property-foo [ 7.143160] ### dt-test ### EXPECT \ : OF: overlay: node_overlaps_later_cs: #6 overlaps with #7 @/testcase-data/overlay-node/test-bus/test-unittest8 [ 7.146130] ### dt-test ### EXPECT \ : OF: overlay: overlay #6 is not topmost [ 7.148434] OF: overlay: node_overlaps_later_cs: #6 overlaps with #7 @/testcase-data/overlay-node/test-bus/test-unittest8 [ 7.151941] OF: overlay: overlay #6 is not topmost [ 7.152965] ### dt-test ### EXPECT / : OF: overlay: overlay #6 is not topmost [ 7.152966] ### dt-test ### EXPECT / : OF: overlay: node_overlaps_later_cs: #6 overlaps with #7 @/testcase-data/overlay-node/test-bus/test-unittest8 [ 7.157527] ### dt-test ### EXPECT \ : i2c i2c-1: Added multiplexed i2c bus 2 [ 7.159418] i2c i2c-0: Added multiplexed i2c bus 1 [ 7.175401] ### dt-test ### EXPECT / : i2c i2c-1: Added multiplexed i2c bus 2 [ 7.175404] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest12/status [ 7.176802] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest12/status [ 7.183238] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest12/status [ 7.183241] ### dt-test ### EXPECT \ : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest13/status [ 7.186407] OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest13/status [ 7.193861] ### dt-test ### EXPECT / : OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest13/status [ 7.193864] ### dt-test ### EXPECT \ : i2c i2c-1: Added multiplexed i2c bus 3 [ 7.200011] i2c i2c-0: Added multiplexed i2c bus 2 [ 7.202698] ### dt-test ### EXPECT / : i2c i2c-1: Added multiplexed i2c bus 3 [ 7.209235] ### dt-test ### EXPECT \ : GPIO line <> (line-B-input) hogged as input [ 7.212134] ### dt-test ### EXPECT \ : GPIO line <> (line-A-input) hogged as input [ 7.213792] GPIO line 509 (line-B-input) hogged as input [ 7.215209] GPIO line 503 (line-A-input) hogged as input [ 7.216541] ### dt-test ### EXPECT / : GPIO line <> (line-A-input) hogged as input [ 7.218292] ### dt-test ### EXPECT / : GPIO line <> (line-B-input) hogged as input [ 7.219753] ### dt-test ### EXPECT \ : GPIO line <> (line-D-input) hogged as input [ 7.224715] GPIO line 501 (line-D-input) hogged as input [ 7.226085] ### dt-test ### EXPECT / : GPIO line <> (line-D-input) hogged as input [ 7.229424] ### dt-test ### EXPECT \ : GPIO line <> (line-C-input) hogged as input [ 7.231653] GPIO line 495 (line-C-input) hogged as input [ 7.232861] ### dt-test ### EXPECT / : GPIO line <> (line-C-input) hogged as input [ 7.239447] ### dt-test ### FAIL of_unittest_overlay_high_level():2982 overlay_base_root not initialized [ 7.240485] ### dt-test ### end of unittest - 254 passed, 1 failed [ 7.570301] CE: hpet increased min_delta_ns to 5000 nsec [ 7.570449] CE: hpet increased min_delta_ns to 7500 nsec [ 7.570563] CE: hpet increased min_delta_ns to 11250 nsec [ 7.570645] CE: hpet increased min_delta_ns to 16875 nsec [ 7.570783] CE: hpet increased min_delta_ns to 25312 nsec [ 9.273375] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX [ 9.276257] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 9.279231] _warn_unseeded_randomness: 27 callbacks suppressed [ 9.279239] random: get_random_bytes called from addrconf_dad_kick+0x55/0xb0 with crng_init=1 [ 9.292890] Sending DHCP requests . [ 9.292901] random: get_random_bytes called from ip_auto_config+0x510/0xebf with crng_init=1 [ 9.293233] , OK [ 9.296007] IP-Config: Got DHCP answer from 10.0.2.2, my address is 10.0.2.15 [ 9.297449] IP-Config: Complete: [ 9.298054] device=eth0, hwaddr=52:54:00:12:34:56, ipaddr=10.0.2.15, mask=255.255.255.0, gw=10.0.2.2 [ 9.299789] host=vm-snb-6, domain=, nis-domain=(none) [ 9.300976] bootserver=10.0.2.2, rootserver=10.0.2.2, rootpath= [ 9.300978] nameserver0=10.0.2.3 [ 9.304270] debug_vm_pgtable: debug_vm_pgtable: Validating architecture page table helpers [ 9.306147] random: get_random_u32 called from debug_vm_pgtable+0x2c/0x6a5 with crng_init=1 [ 9.306206] BUG: non-zero pgtables_bytes on freeing mm: -4096 [ 9.317950] Freeing unused kernel image (initmem) memory: 872K [ 9.319376] Write protecting kernel text and read-only data: 21104k [ 9.322456] NX-protecting the kernel data: 14216k [ 9.324940] x86/mm: Checked W+X mappings: passed, no W+X pages found. [ 9.326221] rodata_test: all tests were successful [ 9.327341] x86/mm: Checking user space page tables [ 9.328395] x86/mm: Checked W+X mappings: passed, no W+X pages found. [ 9.329867] Run /init as init process [ 9.330602] with arguments: [ 9.331216] /init [ 9.331698] with environment: [ 9.332360] HOME=/ [ 9.333015] TERM=linux [ 9.333592] user=lkp [ 9.334128] job=/lkp/jobs/scheduled/vm-snb-6/boot-1-openwrt-i386-generic-20190428.cgz-f8bf55f05f7d665fdf5942ceb28a82089ddad44a-20200328-60525-1ymm2c4-11.yaml [ 9.337271] ARCH=i386 [ 9.337855] kconfig=i386-randconfig-h003-20200326 [ 9.338861] branch=linux-devel/devel-catchup-202003270319 [ 9.340058] commit=f8bf55f05f7d665fdf5942ceb28a82089ddad44a [ 9.341438] BOOT_IMAGE=/pkg/linux/i386-randconfig-h003-20200326/gcc-7/f8bf55f05f7d665fdf5942ceb28a82089ddad44a/vmlinuz-5.6.0-rc7-12014-gf8bf55f05f7d6 [ 9.343123] max_uptime=600 [ 9.343456] RESULT_ROOT=/result/boot/1/vm-snb/openwrt-i386-generic-20190428.cgz/i386-randconfig-h003-20200326/gcc-7/f8bf55f05f7d665fdf5942ceb28a82089ddad44a/8 [ 9.345009] LKP_SERVER=inn [ 9.345337] selinux=0 [ 9.345618] apic=debug [ 9.345908] softlockup_panic=1 [ 9.346285] nmi_watchdog=panic [ 9.346643] prompt_ramdisk=0 [ 9.346984] vga=normal [ 9.347272] watchdog_thresh=60 [ 9.352224] init: Console is alive [ 9.353943] kmodloader: loading kernel modules from /etc/modules-boot.d/* [ 9.355146] kmodloader: done loading kernel modules from /etc/modules-boot.d/* [ 9.367256] init: - preinit - Press the [f] key and hit [enter] to enter failsafe mode Press the [1], [2], [3] or [4] key and hit [enter] to select the debug level [ 10.425360] _warn_unseeded_randomness: 56 callbacks suppressed [ 10.425370] random: get_random_bytes called from flow_hash_from_keys+0xd6/0x1c0 with crng_init=1 [ 10.425630] random: get_random_bytes called from addrconf_dad_kick+0x55/0xb0 with crng_init=1 [ 10.426200] random: get_random_u32 called from arch_pick_mmap_layout+0x59/0x130 with crng_init=1 [ 11.560234] _warn_unseeded_randomness: 3 callbacks suppressed [ 11.560242] random: get_random_u32 called from cache_alloc_refill+0x62d/0xf10 with crng_init=1 [ 11.560951] random: get_random_u32 called from arch_pick_mmap_layout+0x59/0x130 with crng_init=1 [ 11.560960] random: get_random_u32 called from randomize_stack_top+0x1d/0x40 with crng_init=1 [ 12.584597] _warn_unseeded_randomness: 7 callbacks suppressed [ 12.584607] random: get_random_u32 called from arch_pick_mmap_layout+0x59/0x130 with crng_init=1 [ 12.587470] random: get_random_u32 called from randomize_stack_top+0x1d/0x40 with crng_init=1 [ 12.587477] random: get_random_u32 called from arch_align_stack+0x35/0x50 with crng_init=1 [ 12.609699] mount_root: mounting /dev/root [ 12.632418] urandom-seed: Seed file not found (/etc/urandom.seed) [ 12.642196] procd: - early - [ 13.190774] procd: - ubus - [ 13.196472] random: ubusd: uninitialized urandom read (4 bytes read) [ 13.242855] random: ubusd: uninitialized urandom read (4 bytes read) [ 13.244220] random: ubusd: uninitialized urandom read (4 bytes read) [ 13.249986] procd: - init - Please press Enter to activate this console. [ 13.327004] kmodloader: loading kernel modules from /etc/modules.d/* [ 13.330177] kmodloader: done loading kernel modules from /etc/modules.d/* [ 14.336904] _warn_unseeded_randomness: 102 callbacks suppressed [ 14.336912] random: get_random_u32 called from arch_pick_mmap_layout+0x59/0x130 with crng_init=1 [ 14.336922] random: get_random_u32 called from randomize_stack_top+0x1d/0x40 with crng_init=1 [ 14.336927] random: get_random_u32 called from arch_align_stack+0x35/0x50 with crng_init=1 [ 14.556753] urandom_read: 5 callbacks suppressed [ 14.556755] random: jshn: uninitialized urandom read (4 bytes read) [ 14.564888] random: ubusd: uninitialized urandom read (4 bytes read) [ 15.345890] _warn_unseeded_randomness: 615 callbacks suppressed [ 15.345898] random: get_random_u32 called from arch_pick_mmap_layout+0x59/0x130 with crng_init=1 [ 15.345905] random: get_random_u32 called from randomize_stack_top+0x1d/0x40 with crng_init=1 [ 15.345909] random: get_random_u32 called from arch_align_stack+0x35/0x50 with crng_init=1 [ 16.361307] _warn_unseeded_randomness: 390 callbacks suppressed [ 16.361314] random: get_random_u32 called from arch_pick_mmap_layout+0x59/0x130 with crng_init=1 [ 16.361322] random: get_random_u32 called from randomize_stack_top+0x1d/0x40 with crng_init=1 [ 16.361327] random: get_random_u32 called from arch_align_stack+0x35/0x50 with crng_init=1 [ 17.365403] _warn_unseeded_randomness: 284 callbacks suppressed [ 17.365412] random: get_random_u32 called from arch_pick_mmap_layout+0x59/0x130 with crng_init=1 [ 17.365420] random: get_random_u32 called from randomize_stack_top+0x1d/0x40 with crng_init=1 [ 17.365425] random: get_random_u32 called from arch_align_stack+0x35/0x50 with crng_init=1 LKP: HOSTNAME vm-snb-6, MAC 52:54:00:12:34:56, kernel 5.6.0-rc7-12014-gf8bf55f05f7d6 2, serial console /dev/ttyS0 [ 18.346174] Kernel tests: Boot OK! [ 18.346174] /lkp/lkp/src/bin/run-lkp [ 18.346174] RESULT_ROOT=/result/boot/1/vm-snb/openwrt-i386-generic-20190428.cgz/i386-randconfig-h003-20200326/gcc-7/f8bf55f05f7d665fdf5942ceb28a82089ddad44a/8 [ 18.346174] job=/lkp/jobs/scheduled/vm-snb-6/boot-1-openwrt-i386-generic-20190428.cgz-f8bf55f05f7d665fdf5942ceb28a82089ddad44a-20200328-60525-1ymm2c4-11.yaml [ 18.346174] result_service=raw_upload, RESULT_MNT=/inn/result, RESULT_ROOT=/inn/result/boot/1/vm-snb/openwrt-i386-generic-20190428.cgz/i386-randconfig-h003-20200326/gcc-7/f8bf55f05f7d665fdf5942ceb28a82089ddad44a/8 [ 18.346174] run-job /lkp/jobs/scheduled/vm-snb-6/boot-1-openwrt-i386-generic-20190428.cgz-f8bf55f05f7d665fdf5942ceb28a82089ddad44a-20200328-60525-1ymm2c4-11.yaml [ 18.491299] _warn_unseeded_randomness: 216 callbacks suppressed [ 18.491308] random: get_random_u32 called from arch_pick_mmap_layout+0x59/0x130 with crng_init=1 [ 18.491318] random: get_random_u32 called from randomize_stack_top+0x1d/0x40 with crng_init=1 [ 18.491323] random: get_random_u32 called from arch_align_stack+0x35/0x50 with crng_init=1 [ 19.892854] random: crng init done [ 19.893497] random: 82 get_random_xx warning(s) missed due to ratelimiting [ 23.382687] target ucode: [ 24.383652] sleep started [ 25.384495] /bin/wget -q http://inn:80/~lkp/cgi-bin/lkp-jobfile-append-var?job_file=/lkp/jobs/scheduled/vm-snb-6/boot-1-openwrt-i386-generic-20190428.cgz-f8bf55f05f7d665fdf5942ceb28a82089ddad44a-20200328-60525-1ymm2c4-11.yaml&job_state=post_run -O /dev/null [ 32.652245] kill 869 vmstat --timestamp -n 10 [ 32.652245] kill 865 cat /proc/kmsg [ 32.652245] wait for background processes: 878 873 oom-killer meminfo [ 34.365971] CE: hpet increased min_delta_ns to 37968 nsec [ 35.265079] CE: hpet increased min_delta_ns to 56952 nsec [ 36.654596] /bin/wget -q http://inn:80/~lkp/cgi-bin/lkp-jobfile-append-var?job_file=/lkp/jobs/scheduled/vm-snb-6/boot-1-openwrt-i386-generic-20190428.cgz-f8bf55f05f7d665fdf5942ceb28a82089ddad44a-20200328-60525-1ymm2c4-11.yaml&loadavg=1.46%200.37%200.12%201/75%201017&start_time=1585341190&end_time=1585341191&version=/lkp/lkp/.src-20200327-172855:1a2d9638:5a9d8b33b& -O /dev/null To reproduce: # build kernel cd linux cp config-5.6.0-rc7-12014-gf8bf55f05f7d6 .config make HOSTCC=gcc-7 CC=gcc-7 ARCH=i386 olddefconfig prepare modules_prepare bzImage git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, lkp