FYI, we noticed the following commit (built with gcc-7): commit: 2ce62cbf3ebf647d3ef3640969b81e8b0b9466ad ("srcu: Allocate per-CPU data for DEFINE_SRCU() in modules") https://git.kernel.org/cgit/linux/kernel/git/paulmck/linux-rcu.git dev.2019.04.28a in testcase: locktorture with following parameters: runtime: 300s test: cpuhotplug test-description: This torture test consists of creating a number of kernel threads which acquire the lock and hold it for specific amount of time, thus simulating different critical region behaviors. test-url: https://www.kernel.org/doc/Documentation/locking/locktorture.txt on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 2G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +-----------------------------------------------------------------------------+------------+------------+ | | dccea1a8c4 | 2ce62cbf3e | +-----------------------------------------------------------------------------+------------+------------+ | boot_successes | 6 | 0 | | boot_failures | 4 | 10 | | BUG:kernel_reboot-without-warning_in_test_stage | 4 | | | kobject(#):tried_to_init_an_initialized_object,something_is_seriously_wrong | 0 | 10 | | general_protection_fault:#[##] | 0 | 1 | | RIP:string | 0 | 1 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 1 | | BUG:kernel_hang_in_test_stage | 0 | 1 | +-----------------------------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot <lkp(a)intel.com&gt; [ 23.381931] [TTM] Finalizing DMA pool allocator LKP: HOSTNAME vm-snb-2G-162, MAC 52:54:00:12:34:56, kernel 5.1.0-rc1-00102-g2ce62cb 1, serial console /dev/ttyS0 [ 23.407428] [TTM] Zone kernel: Used memory at exit: 0 kiB [ 23.441178] [drm] Found bochs VGA, ID 0xb0c0. [ 23.442080] [drm] Framebuffer size 16384 kB @ 0xfd000000, mmio @ 0xfebf0000. [ 23.482582] kobject ((____ptrval____)): tried to init an initialized object, something is seriously wrong. [ 23.484087] CPU: 0 PID: 348 Comm: systemd-udevd Not tainted 5.1.0-rc1-00102-g2ce62cb #1 [ 23.485247] Call Trace: [ 23.485633] dump_stack+0x6c/0x8f [ 23.486173] kobject_init+0x45/0xa5 [ 23.486748] kobject_init_and_add+0x3d/0xa6 [ 23.487541] ? __module_address+0x8b/0xac [ 23.488122] ? is_module_address+0x10/0x1f [ 23.488729] ? static_obj+0x32/0x4a [ 23.489236] ? 0xffffffffa00ef000 [ 23.489781] ttm_mem_global_init+0xb6/0x319 [ttm] [ 23.490525] ? vprintk_func+0xd1/0xda [ 23.491139] ? drm_dbg+0x7e/0x8b [drm] [ 23.491714] ? printk+0x53/0x5b [ 23.492176] ttm_bo_device_init+0x68/0x2c3 [ttm] [ 23.492913] bochs_mm_init+0x40/0xa8 [bochs_drm] [ 23.493761] bochs_pci_probe+0x117/0x17f [bochs_drm] [ 23.494837] local_pci_probe+0x47/0x9d [ 23.495594] pci_device_probe+0x17f/0x1cd [ 23.496443] ? pci_device_remove+0xcf/0xcf [ 23.497255] really_probe+0x255/0x584 [ 23.498033] ? pm_runtime_put_noidle+0x1c/0x1f [ 23.498958] driver_probe_device+0x128/0x176 [ 23.499834] device_driver_attach+0x4e/0x6a [ 23.500737] __driver_attach+0x170/0x182 [ 23.501538] ? device_driver_attach+0x6a/0x6a [ 23.502398] bus_for_each_dev+0x9d/0xc5 [ 23.503143] driver_attach+0x22/0x25 [ 23.503848] bus_add_driver+0x157/0x240 [ 23.504622] driver_register+0xe4/0x131 [ 23.505361] __pci_register_driver+0x78/0x7f [ 23.506189] bochs_init+0x62/0x1000 [bochs_drm] [ 23.507075] ? 0xffffffffa012e000 [ 23.507921] do_one_initcall+0x7f/0x17f [ 23.508785] ? cache_alloc_debugcheck_after+0x4b/0x148 [ 23.509793] ? do_init_module+0x21/0x3b1 [ 23.510569] ? kmem_cache_alloc+0x9b/0xbb [ 23.511393] do_init_module+0x5a/0x3b1 [ 23.512133] load_module+0x11c6/0x1786 [ 23.512878] ? vfs_read+0xf3/0x102 [ 23.519413] ? allow_write_access+0x27/0x2a [ 23.520276] ? kernel_read_file+0x17f/0x191 [ 23.521214] __do_sys_finit_module+0xb5/0xc5 [ 23.522138] ? __do_sys_finit_module+0xb5/0xc5 [ 23.523121] __x64_sys_finit_module+0x15/0x17 [ 23.524236] do_syscall_64+0x1a0/0x1bd [ 23.525042] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 23.526078] RIP: 0033:0x7f1b0a25a229 [ 23.526845] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 3f 4c 2b 00 f7 d8 64 89 01 48 [ 23.530673] RSP: 002b:00007ffd8ca3e9f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 23.532210] RAX: ffffffffffffffda RBX: 0000559388c5d5a0 RCX: 00007f1b0a25a229 [ 23.533655] RDX: 0000000000000000 RSI: 00007f1b0ab73265 RDI: 0000000000000014 [ 23.535344] RBP: 00007f1b0ab73265 R08: 0000000000000000 R09: 00007ffd8ca3ef70 [ 23.536799] R10: 0000000000000014 R11: 0000000000000246 R12: 0000000000000000 [ 23.538252] R13: 0000559388c5cb30 R14: 0000000000020000 R15: 000055938884ecbc [ 23.539976] [TTM] Zone kernel: Available graphics memory: 1007378 kiB [ 23.541308] [TTM] Zone kernel: Available graphics memory: 1007378 kiB [ 23.542643] [TTM] Initializing pool allocator [ 23.543570] [TTM] Initializing DMA pool allocator [ 23.544623] kobject ((____ptrval____)): tried to init an initialized object, something is seriously wrong. [ 23.546549] CPU: 0 PID: 348 Comm: systemd-udevd Not tainted 5.1.0-rc1-00102-g2ce62cb #1 [ 23.548159] Call Trace: [ 23.548694] dump_stack+0x6c/0x8f [ 23.549389] kobject_init+0x45/0xa5 [ 23.550098] kobject_init_and_add+0x3d/0xa6 [ 23.550961] ? alloc_pages_current+0xcb/0xdb [ 23.551860] ttm_bo_device_init+0x156/0x2c3 [ttm] [ 23.552850] bochs_mm_init+0x40/0xa8 [bochs_drm] [ 23.553817] bochs_pci_probe+0x117/0x17f [bochs_drm] [ 23.554945] local_pci_probe+0x47/0x9d [ 23.555560] piix4_smbus 0000:00:01.3: SMBus Host Controller at 0x700, revision 0 [ 23.566712] pci_device_probe+0x17f/0x1cd [ 23.566721] ? pci_device_remove+0xcf/0xcf [ 23.566732] really_probe+0x255/0x584 [ 23.576323] ? pm_runtime_put_noidle+0x1c/0x1f [ 23.577326] driver_probe_device+0x128/0x176 [ 23.578213] device_driver_attach+0x4e/0x6a [ 23.581556] __driver_attach+0x170/0x182 [ 23.582294] ? device_driver_attach+0x6a/0x6a [ 23.583115] bus_for_each_dev+0x9d/0xc5 [ 23.583852] driver_attach+0x22/0x25 [ 23.584553] bus_add_driver+0x157/0x240 [ 23.585292] driver_register+0xe4/0x131 [ 23.586166] __pci_register_driver+0x78/0x7f [ 23.586987] bochs_init+0x62/0x1000 [bochs_drm] [ 23.587839] ? 0xffffffffa012e000 [ 23.588481] do_one_initcall+0x7f/0x17f [ 23.589209] ? cache_alloc_debugcheck_after+0x4b/0x148 [ 23.590167] ? do_init_module+0x21/0x3b1 [ 23.590913] ? kmem_cache_alloc+0x9b/0xbb [ 23.591676] do_init_module+0x5a/0x3b1 [ 23.592395] load_module+0x11c6/0x1786 [ 23.593109] ? vfs_read+0xf3/0x102 [ 23.593740] ? allow_write_access+0x27/0x2a [ 23.594511] ? kernel_read_file+0x17f/0x191 [ 23.595269] __do_sys_finit_module+0xb5/0xc5 [ 23.596054] ? __do_sys_finit_module+0xb5/0xc5 [ 23.596865] __x64_sys_finit_module+0x15/0x17 [ 23.597656] do_syscall_64+0x1a0/0x1bd [ 23.598345] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 23.599297] RIP: 0033:0x7f1b0a25a229 [ 23.599976] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 3f 4c 2b 00 f7 d8 64 89 01 48 [ 23.603530] RSP: 002b:00007ffd8ca3e9f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 23.604925] RAX: ffffffffffffffda RBX: 0000559388c5d5a0 RCX: 00007f1b0a25a229 [ 23.606369] RDX: 0000000000000000 RSI: 00007f1b0ab73265 RDI: 0000000000000014 [ 23.607728] RBP: 00007f1b0ab73265 R08: 0000000000000000 R09: 00007ffd8ca3ef70 [ 23.609066] R10: 0000000000000014 R11: 0000000000000246 R12: 0000000000000000 [ 23.612060] R13: 0000559388c5cb30 R14: 0000000000020000 R15: 000055938884ecbc [ 23.625106] [drm] Initialized bochs-drm 1.0.0 20130925 for 0000:00:02.0 on minor 0 [ 23.830835] Probing IDE interface ide1... [ 23.949174] input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input6 To reproduce: # build kernel cd linux cp config-5.1.0-rc1-00102-g2ce62cb .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 find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz bin/lkp qemu -k <bzImage> -m modules.cgz job-script # job-script is attached in this email Thanks, lkp