FYI, we noticed the following commit (built with gcc-7): commit: 0e2bc33d204ba5407465d09f8622077ad5739839 ("x86/alternatives: Teach text_poke_bp() to emulate instructions") https://git.kernel.org/cgit/linux/kernel/git/peterz/queue.git x86/static_call in testcase: boot 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): +-------------------------------------------------------+------------+------------+ | | 68b46ce8b9 | 0e2bc33d20 | +-------------------------------------------------------+------------+------------+ | boot_successes | 91 | 64 | | boot_failures | 21 | 42 | | BUG:kernel_reboot-without-warning_in_test_stage | 21 | 11 | | BUG:kernel_NULL_pointer_dereference,address | 0 | 24 | | Oops:#[##] | 0 | 31 | | RIP:native_write_msr | 0 | 3 | | Kernel_panic-not_syncing:Fatal_exception_in_interrupt | 0 | 29 | | RIP:native_safe_halt | 0 | 22 | | RIP:smp_call_function_single | 0 | 17 | | RIP:on_each_cpu | 0 | 1 | | BUG:unable_to_handle_page_fault_for_address | 0 | 7 | | RIP:__text_poke | 0 | 1 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 2 | +-------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot <lkp(a)intel.com&gt; [ 2.869246] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 2.869246] #PF: supervisor instruction fetch in kernel mode [ 2.869246] #PF: error_code(0x0010) - not-present page [ 2.869246] PGD 0 P4D 0 [ 2.869246] Oops: 0010 [#1] SMP PTI [ 2.869246] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc4-00079-g0e2bc33 #1 [ 2.869246] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 2.869246] RIP: 0010:0x0 [ 2.869246] Code: Bad RIP value. [ 2.869246] RSP: 0000:ffffbcc1c0003f98 EFLAGS: 00010087 [ 2.869246] RAX: 0000000000005ba8 RBX: ffffffffb6114f5f RCX: ffff9eb8f00177f0 [ 2.869246] RDX: 0000000000000000 RSI: 00000000000f4240 RDI: 0000000000d8abf8 [ 2.869246] RBP: ffff9eb8ef4b3c00 R08: 0000000000000000 R09: 0000000000000000 [ 2.869246] R10: 0000000000000000 R11: 0000003b9aca0000 R12: 0000000000000000 [ 2.869246] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 2.869246] FS: 0000000000000000(0000) GS:ffff9eb8f0000000(0000) knlGS:0000000000000000 [ 2.869246] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.869246] CR2: ffffffffffffffd6 CR3: 000000006660a000 CR4: 00000000000406f0 [ 2.869246] Call Trace: [ 2.869246] <IRQ> [ 2.869246] update_process_times+0x1c/0x50 [ 2.869246] tick_periodic+0x27/0x80 [ 2.869246] tick_handle_periodic+0x20/0x60 [ 2.869246] smp_apic_timer_interrupt+0x6a/0x150 [ 2.869246] apic_timer_interrupt+0xf/0x20 [ 2.869246] </IRQ> [ 2.869246] RIP: 0010:smp_call_function_single+0xea/0x110 [ 2.869246] Code: 00 00 00 75 44 48 83 c4 48 41 5a 5d 49 8d 62 f8 c3 48 89 d1 48 89 f2 48 8d 75 b0 e8 60 fe ff ff 8b 55 c8 83 e2 01 74 0a f3 90 <8b> 55 c8 83 e2 01 75 f6 eb bb 8b 05 86 57 c7 01 85 c0 0f 85 76 ff [ 2.869246] RSP: 0000:ffffbcc1c0327d60 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 [ 2.869246] RAX: 0000000000000000 RBX: ffffffffb7dcc8d2 RCX: 0000000000000830 [ 2.869246] RDX: 0000000000000001 RSI: 00000000000000fb RDI: 0000000000000830 [ 2.869246] RBP: ffffbcc1c0327db0 R08: 0000000000000001 R09: 0000000000000001 [ 2.869246] R10: ffffbcc1c0327dd8 R11: 00000000000001a9 R12: 0000000000000000 [ 2.869246] R13: ffffffffb7dcc932 R14: 0000000000000000 R15: 0000000000000000 [ 2.869246] ? poke_int3_handler+0xe0/0xe0 [ 2.869246] ? cpumask_next_and+0x19/0x20 [ 2.869246] ? smp_call_function_many+0xa8/0x230 [ 2.869246] ? poke_int3_handler+0xe0/0xe0 [ 2.869246] ? on_each_cpu+0x36/0x70 [ 2.869246] on_each_cpu+0x36/0x70 [ 2.869246] text_poke_bp_batch+0x8b/0x150 [ 2.869246] ? kvm_init_platform+0x16/0x16 [ 2.869246] ? set_debug_rodata+0x11/0x11 [ 2.869246] arch_jump_label_transform_apply+0x2f/0x50 [ 2.869246] static_key_slow_inc_cpuslocked+0x8d/0xa0 [ 2.869246] static_key_slow_inc+0x16/0x20 [ 2.869246] activate_jump_labels+0x1a/0x32 [ 2.869246] do_one_initcall+0x46/0x214 [ 2.869246] kernel_init_freeable+0x1bb/0x278 [ 2.869246] ? rest_init+0xd0/0xd0 [ 2.869246] kernel_init+0xa/0x110 [ 2.869246] ret_from_fork+0x35/0x40 [ 2.869246] Modules linked in: [ 2.869246] CR2: 0000000000000000 [ 2.870246] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 2.869246] ---[ end trace 0d81c5e5ac5901cf ]--- To reproduce: # build kernel cd linux cp config-5.2.0-rc4-00079-g0e2bc33 .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 bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email Thanks, lkp