FYI, we noticed the following commit (built with gcc-8): commit: 6579c39594aeb9da617e319dbb679ded14c05105 ("drm/bochs: atomic: switch planes to atomic, wire up helpers.") https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master in testcase: trinity with following parameters: runtime: 300s test-description: Trinity is a linux system call fuzz tester. test-url: http://codemonkey.org.uk/projects/trinity/ 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): +--------------------------------------------------------------------------------------------+------------+------------+ | | 6309200184 | 6579c39594 | +--------------------------------------------------------------------------------------------+------------+------------+ | boot_successes | 0 | 0 | | boot_failures | 10 | 12 | | kobject((____ptrval____)):tried_to_init_an_initialized_object,something_is_seriously_wrong | 10 | 12 | | BUG:unable_to_handle_kernel | 2 | 1 | | Oops:#[##] | 2 | 1 | | RIP:dd_insert_requests | 2 | 1 | | Kernel_panic-not_syncing:Fatal_exception | 2 | 1 | | WARNING:at_drivers/gpu/drm/drm_mode_config.c:#drm_mode_config_cleanup | 0 | 12 | | RIP:drm_mode_config_cleanup | 0 | 12 | +--------------------------------------------------------------------------------------------+------------+------------+ [ 22.270322] WARNING: CPU: 1 PID: 1 at drivers/gpu/drm/drm_mode_config.c:456 drm_mode_config_cleanup+0xa4/0x2a4 [ 22.272861] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc1-00131-g6579c39 #1 [ 22.272861] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 22.272861] RIP: 0010:drm_mode_config_cleanup+0xa4/0x2a4 [ 22.272861] Code: ff eb e8 48 89 e7 e8 22 9c ff ff 48 8d bb 80 08 00 00 e8 7e d4 8b ff 48 8b 83 68 08 00 00 48 8d 93 68 08 00 00 48 39 c2 74 37 <0f> 0b 48 89 e6 48 89 df 48 c7 c5 93 bc 65 83 e8 0c 9b ff ff 48 89 [ 22.272861] RSP: 0000:ffff88813a243cd8 EFLAGS: 00010206 [ 22.272861] RAX: ffff8881247a2738 RBX: ffff888139d9c000 RCX: 0000000000001150 [ 22.272861] RDX: ffff888139d9c868 RSI: 000000007fffffff RDI: ffff888139d9c880 [ 22.272861] RBP: ffff888139d9c8d0 R08: 00000000be162c32 R09: 0000000000000004 [ 22.272861] R10: ffffffff840eebd4 R11: 0000000000000002 R12: ffff888139d9c8d8 [ 22.272861] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 [ 22.272861] FS: 0000000000000000(0000) GS:ffff88813b200000(0000) knlGS:0000000000000000 [ 22.272861] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 22.272861] CR2: 00000000ffffffff CR3: 0000000003a8a000 CR4: 00000000000406e0 [ 22.272861] Call Trace: [ 22.272861] bochs_kms_fini+0x1b/0x25 [ 22.272861] bochs_unload+0x1e/0x41 [ 22.272861] bochs_pci_remove+0x1d/0x26 [ 22.272861] pci_device_remove+0x36/0x8e [ 22.272861] really_probe+0x1d4/0x3ea [ 22.272861] driver_probe_device+0xd4/0x104 [ 22.272861] __driver_attach+0xcb/0xfc [ 22.272861] ? driver_probe_device+0x104/0x104 [ 22.272861] bus_for_each_dev+0x71/0xa3 [ 22.272861] bus_add_driver+0x134/0x20e [ 22.272861] ? qxl_init+0x47/0x47 [ 22.272861] driver_register+0x99/0xcb [ 22.272861] ? qxl_init+0x47/0x47 [ 22.272861] do_one_initcall+0xb3/0x1c6 [ 22.272861] kernel_init_freeable+0x207/0x297 [ 22.272861] ? rest_init+0x13b/0x13b [ 22.272861] kernel_init+0xa/0xff [ 22.272861] ret_from_fork+0x1f/0x30 [ 22.272861] _warn_unseeded_randomness: 16 callbacks suppressed [ 22.272861] random: get_random_bytes called from init_oops_id+0x22/0x31 with crng_init=0 [ 22.272861] ---[ end trace c320b1bd2fc19904 ]--- To reproduce: 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, Rong Chen