FYI, we noticed the following commit: https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git x86/vmap_stack commit ddf4847e6f114c522fefb24c16fc7a1d75138f9f ("x86: Move thread_info into task_struct") on test machine: vm-kbuild-yocto-x86_64: 1 threads qemu-system-x86_64 -enable-kvm -cpu SandyBridge with 320M memory caused below changes: +------------------------------------------+------------+------------+ | | aeea9c1c41 | ddf4847e6f | +------------------------------------------+------------+------------+ | boot_successes | 6 | 0 | | boot_failures | 0 | 8 | | BUG:unable_to_handle_kernel | 0 | 8 | | Oops:#[##] | 0 | 8 | | RIP:entry_SYSCALL_64_after_swapgs | 0 | 8 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 8 | +------------------------------------------+------------+------------+ [ 10.105818] Freeing unused kernel memory: 1956K (ffff880001617000 - ffff880001800000) [ 10.113305] Freeing unused kernel memory: 836K (ffff880001b2f000 - ffff880001c00000) [ 10.132456] x86/mm: Checked W+X mappings: passed, no W+X pages found. [ 10.134895] BUG: unable to handle kernel paging request at ffffffff03862040 [ 10.136663] IP: [<ffffffff81610249>] entry_SYSCALL_64_after_swapgs+0x36/0x4c [ 10.138365] PGD 1c0d067 PUD 0 [ 10.139426] Oops: 0000 [#1] [ 10.140235] Modules linked in: [ 10.141200] CPU: 0 PID: 1 Comm: init Not tainted 4.7.0-rc4-00254-gddf4847 #1 [ 10.142752] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 10.147089] task: ffff88001205c040 ti: ffff88001205c040 task.ti: ffff88001205c040 [ 10.148945] RIP: 0010:[<ffffffff81610249>] [<ffffffff81610249>] entry_SYSCALL_64_after_swapgs+0x36/0x4c [ 10.151240] RSP: 0018:ffff880012063f58 EFLAGS: 00010082 [ 10.152485] RAX: 000000000000000c RBX: 0000000000000008 RCX: 00007f9b93195c9a [ 10.154058] RDX: 0000000000000000 RSI: 00007f9b931994a0 RDI: 0000000000000000 [ 10.155635] RBP: 00000000078bfbff R08: 00007ffe3cb83479 R09: 00007ffe3cbef000 [ 10.157205] R10: 000000000000037f R11: 0000000000000246 R12: 00007ffe3cb83489 [ 10.158778] R13: 0000000000000000 R14: 00000000004028c4 R15: 0000000000001000 [ 10.160481] FS: 0000000000000000(0000) GS:ffffffff81c2f000(0000) knlGS:0000000000000000 [ 10.163887] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 10.165221] CR2: ffffffff03862040 CR3: 0000000013928000 CR4: 00000000000406b0 [ 10.166802] Stack: [ 10.167469] 00007f9b93181a18 00007f9b93181320 00007f9b93181a18 0000000000000046 [ 10.169734] ffff880012063f98 ffffffff810a5c6a 0000000000000246 000000000000037f [ 10.171982] 00007ffe3cbef000 00007ffe3cb83479 ffffffffffffffda 00007f9b93195c9a [ 10.174223] Call Trace: [ 10.174990] [<ffffffff810a5c6a>] ? trace_hardirqs_off_caller+0x36/0xa4 [ 10.176457] Code: 25 84 a3 c2 81 e8 f4 0d 9f ff 6a 2b ff 34 25 00 80 c2 81 41 53 6a 33 51 50 57 56 52 51 6a da 41 50 41 51 41 52 41 53 48 83 ec 30 <65> 4c 8b 1c 25 40 30 c3 81 41 f7 03 ff ff 08 10 0f 85 c2 00 00 [ 10.194036] RIP [<ffffffff81610249>] entry_SYSCALL_64_after_swapgs+0x36/0x4c [ 10.195727] RSP <ffff880012063f58> [ 10.196655] CR2: ffffffff03862040 [ 10.197564] ---[ end trace bedce588960ef6c2 ]--- [ 10.198696] Kernel panic - not syncing: Fatal exception FYI, raw QEMU command line is: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -kernel /pkg/linux/x86_64-randconfig-h0-06262018/gcc-6/ddf4847e6f114c522fefb24c16fc7a1d75138f9f/vmlinuz-4.7.0-rc4-00254-gddf4847 -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-kbuild-yocto-x86_64-51/bisect_boot-1-yocto-minimal-x86_64.cgz-x86_64-randconfig-h0-06262018-ddf4847e6f114c522fefb24c16fc7a1d75138f9f-20160627-110660-dxqka-0.yaml ARCH=x86_64 kconfig=x86_64-randconfig-h0-06262018 branch=linux-devel/devel-catchup-201606270129 commit=ddf4847e6f114c522fefb24c16fc7a1d75138f9f BOOT_IMAGE=/pkg/linux/x86_64-randconfig-h0-06262018/gcc-6/ddf4847e6f114c522fefb24c16fc7a1d75138f9f/vmlinuz-4.7.0-rc4-00254-gddf4847 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-kbuild-yocto-x86_64/yocto-minimal-x86_64.cgz/x86_64-randconfig-h0-06262018/gcc-6/ddf4847e6f114c522fefb24c16fc7a1d75138f9f/0 LKP_SERVER=inn earlyprintk=ttyS0,115200 systemd.log_level=err debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal rw ip=::::vm-kbuild-yocto-x86_64-51::dhcp drbd.minor_count=8' -initrd /fs/sdf1/initrd-vm-kbuild-yocto-x86_64-51 -m 320 -smp 1 -device e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -drive file=/fs/sdf1/disk0-vm-kbuild-yocto-x86_64-51,media=disk,if=virtio -pidfile /dev/shm/kboot/pid-vm-kbuild-yocto-x86_64-51 -serial file:/dev/shm/kboot/serial-vm-kbuild-yocto-x86_64-51 -daemonize -display none -monitor null Thanks, Kernel Test Robot