On May 4, 2019, at 11:25 PM, kernel test robot <lkp(a)intel.com&gt; wrote: FYI, we noticed the following commit (built with gcc-7): commit: 4fc19708b165c1c152fa1f12f6600e66184b7786 ("x86/alternatives: Initialize temporary mm for patching") https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.ker... master in testcase: trinity with following parameters: runtime: 300s test-description: Trinity is a linux system call fuzz tester. test-url: https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fcodemonk... 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): +------------------------------------------+------------+------------+ | | 13585fa066 | 4fc19708b1 | +------------------------------------------+------------+------------+ | boot_successes | 4 | 0 | | boot_failures | 0 | 4 | | kernel_BUG_at_arch/x86/mm/init.c | 0 | 4 | | invalid_opcode:#[##] | 0 | 4 | | EIP:poking_init | 0 | 4 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 4 | +------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot <lkp(a)intel.com&gt; [ 5.118979] kernel BUG at arch/x86/mm/init.c:716! [ 5.119018] invalid opcode: 0000 [#1] SMP [ 5.122979] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.1.0-rc7-00022-g4fc1970 #1 [ 5.122979] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 5.122979] EIP: poking_init+0x21/0xb8 [ 5.122979] Code: db 8d 65 f4 5b 5e 5f 5d c3 55 89 e5 53 52 8b 1d f8 2e 5e db 31 eb 81 f3 e3 02 89 18 e8 43 a2 1d ff a3 0c a1 56 db 85 c0 75 02 <0f> 0b d1 c3 c7 05 08 a1 56 db 00 00 00 40 b8 28 1b 48 db e8 82 a9 [ 5.122979] EAX: 00000000 EBX: 239c2c8f ECX: da865bad EDX: 00000007 [ 5.122979] ESI: 000003ca EDI: 00000000 EBP: db5bff78 ESP: db5bff70 [ 5.122979] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210246 [ 5.122979] CR0: 80050033 CR2: ffffffff CR3: 1b766000 CR4: 000006b0 [ 5.122979] Call Trace: [ 5.122979] start_kernel+0x447/0x47b [ 5.122979] i386_start_kernel+0xd6/0xee [ 5.122979] startup_32_smp+0x15f/0x170 [ 5.122979] Modules linked in: [ 5.123041] random: get_random_bytes called from print_oops_end_marker+0x4f/0x60 with crng_init=0 [ 5.127013] ---[ end trace 790e10dcf838c933 ]--- To reproduce: # build kernel cd linux cp config-5.1.0-rc7-00022-g4fc1970 .config make HOSTCC=gcc-7 CC=gcc-7 ARCH=i386 olddefconfig make HOSTCC=gcc-7 CC=gcc-7 ARCH=i386 prepare make HOSTCC=gcc-7 CC=gcc-7 ARCH=i386 modules_prepare make HOSTCC=gcc-7 CC=gcc-7 ARCH=i386 SHELL=/bin/bash make HOSTCC=gcc-7 CC=gcc-7 ARCH=i386 bzImage git clone https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.... cd lkp-tests bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email Thanks, lkp <config-5.1.0-rc7-00022-g4fc1970><job-script.txt><dmesg.xz>