FYI, we noticed the following commit (built with gcc-7): commit: 4d7883fabfdc73e271e75c9b0b7866ea7e7ae699 ("drm: Set final_kfree in drm_dev_alloc") url: https://github.com/0day-ci/linux/commits/UPDATE-20200326-004731/Daniel-Vetter/drm_device-managed-resources-v5/20200324-045435 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): +-----------------------------------------------------------------------------+------------+------------+ | | 7f89874a78 | 4d7883fabf | +-----------------------------------------------------------------------------+------------+------------+ | boot_successes | 11 | 0 | | boot_failures | 1 | 11 | | BUG:kernel_hang_in_early-boot_stage,last_printk:early_console_in_setup_code | 1 | | | WARNING:at_drivers/gpu/drm/drm_managed.c:#drmm_add_final_kfree[drm] | 0 | 11 | | RIP:drmm_add_final_kfree[drm] | 0 | 11 | +-----------------------------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 249.726375] WARNING: CPU: 0 PID: 334 at drivers/gpu/drm/drm_managed.c:119 drmm_add_final_kfree+0x3d/0x50 [drm] [ 249.728604] Modules linked in: bochs_drm(+) drm_vram_helper drm_ttm_helper ttm drm_kms_helper drm psmouse i6300esb qemu_fw_cfg drm_panel_orientation_quirks [ 249.731136] CPU: 0 PID: 334 Comm: udevd Not tainted 5.6.0-rc7-01663-g4d7883fabfdc7 #1 [ 249.732599] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 [ 249.734188] RIP: 0010:drmm_add_final_kfree+0x3d/0x50 [drm] [ 249.735169] Code: 25 48 89 ef e8 f4 42 18 e1 48 8d 93 c0 05 00 00 48 01 e8 48 39 c2 73 12 48 89 6b 30 5b 5d c3 0f 0b 48 39 eb 73 db 0f 0b eb d7 <0f> 0b 48 89 6b 30 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 41 54 55 [ 249.738423] RSP: 0018:ffff888220fe3b58 EFLAGS: 00010246 [ 249.739410] RAX: ffff88822199ade0 RBX: ffff88822199a820 RCX: 0000000000000000 [ 249.740764] RDX: ffff88822199ade0 RSI: ffff88822199a820 RDI: ffff88822199a820 [ 249.742147] RBP: ffff88822199a820 R08: 3a30303a30303030 R09: 00302e32303a3030 [ 249.743487] R10: ffff888220beb000 R11: 000000000000000b R12: ffff888236b1a0b0 [ 249.744866] R13: ffffffffa0107000 R14: 0000000000000005 R15: ffffffffa01072c0 [ 249.746231] FS: 00007fe4e9609300(0000) GS:ffffffff82a2d000(0000) knlGS:0000000000000000 [ 249.747730] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 249.748839] CR2: 0000000000243000 CR3: 0000000220fb8000 CR4: 00000000000406b0 [ 249.752487] Call Trace: [ 249.752944] drm_dev_alloc+0x47/0x70 [drm] [ 249.753713] bochs_pci_probe+0x65/0x130 [bochs_drm] [ 249.754653] ? pci_match_device+0xc5/0xf0 [ 249.755432] pci_device_probe+0xb3/0x120 [ 249.756164] really_probe+0xe4/0x320 [ 249.756870] device_driver_attach+0x4a/0x50 [ 249.757689] __driver_attach+0x67/0xb0 [ 249.758426] ? device_driver_attach+0x50/0x50 [ 249.759270] bus_for_each_dev+0x60/0x90 [ 249.759984] bus_add_driver+0x170/0x1f0 [ 249.760726] ? 0xffffffffa010a000 [ 249.761391] driver_register+0x56/0xf0 [ 249.762115] ? 0xffffffffa010a000 [ 249.762451] do_one_initcall+0x49/0x1e0 [ 249.762834] ? do_init_module+0x16/0x1de [ 249.763236] ? __kmalloc+0x57/0x180 [ 249.763586] ? trace_hardirqs_on+0x2a/0xc0 [ 249.763993] do_init_module+0x4e/0x1de [ 249.764366] load_module+0x16d5/0x1cc0 [ 249.764739] ? __do_sys_finit_module+0x96/0xb0 [ 249.765178] __do_sys_finit_module+0x96/0xb0 [ 249.765603] do_syscall_64+0x6a/0x240 [ 249.765969] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 249.766484] RIP: 0033:0x7fe4e971eb99 [ 249.766842] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d c7 12 0c 00 f7 d8 64 89 01 48 [ 249.768639] RSP: 002b:00007ffe2c279298 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 249.769372] RAX: ffffffffffffffda RBX: 0000558a63e342b0 RCX: 00007fe4e971eb99 [ 249.770078] RDX: 0000000000000000 RSI: 00007fe4e97f71e3 RDI: 000000000000000f [ 249.771197] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 249.772544] R10: 000000000000000f R11: 0000000000000246 R12: 00007fe4e97f71e3 [ 249.773896] R13: 0000000000020000 R14: 00007ffe2c279390 R15: 0000000000000000 [ 249.775227] ---[ end trace f8d95502aef0064a ]--- To reproduce: # build kernel cd linux cp config-5.6.0-rc7-01663-g4d7883fabfdc7 .config make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 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, Rong Chen