Hello, kernel test robot noticed "kernel_BUG_at_arch/x86/kernel/alternative.c" on: commit: a512fcf757ce329c284853fbe1e8bd9b810fc975 ("x86/ibt: Implement IBT+") https://git.kernel.org/cgit/linux/kernel/git/peterz/queue.git x86/ibt in testcase: boot compiler: clang-18 test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G (please refer to attached dmesg/kmsg for entire log/backtrace) +---------------------------------------------+------------+------------+ | | e78683161e | a512fcf757 | +---------------------------------------------+------------+------------+ | boot_successes | 18 | 0 | | boot_failures | 0 | 18 | | kernel_BUG_at_arch/x86/kernel/alternative.c | 0 | 18 | | Oops:invalid_opcode:#[##]PREEMPT_SMP_PTI | 0 | 18 | | RIP:apply_direct_call_offset | 0 | 18 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 18 | +---------------------------------------------+------------+------------+ If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-lkp/202410111436.282a8f8a-lkp@xxxxxxxxx [ 0.596045][ T0] ------------[ cut here ]------------ [ 0.596942][ T0] kernel BUG at arch/x86/kernel/alternative.c:302! [ 0.597962][ T0] Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 0.599029][ T0] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc2-00010-ga512fcf757ce #1 [ 0.599197][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 0.599197][ T0] RIP: 0010:apply_direct_call_offset (arch/x86/kernel/alternative.c:302) [ 0.599197][ T0] Code: 04 eb db 83 f8 0f 75 0f 80 7c 24 19 8f 7f 1d 43 83 44 2e 02 04 eb c7 3d eb 00 00 00 74 a3 eb 0c 0f 0b eb ba f3 0f 1e fa eb b4 <0f> 0b 0f b6 54 24 52 48 c7 c7 1c 7e 89 82 4c 89 e6 4c 89 e1 e8 43 All code ======== 0: 04 eb add $0xeb,%al 2: db 83 f8 0f 75 0f fildl 0xf750ff8(%rbx) 8: 80 7c 24 19 8f cmpb $0x8f,0x19(%rsp) d: 7f 1d jg 0x2c f: 43 83 44 2e 02 04 addl $0x4,0x2(%r14,%r13,1) 15: eb c7 jmp 0xffffffffffffffde 17: 3d eb 00 00 00 cmp $0xeb,%eax 1c: 74 a3 je 0xffffffffffffffc1 1e: eb 0c jmp 0x2c 20: 0f 0b ud2 22: eb ba jmp 0xffffffffffffffde 24: f3 0f 1e fa endbr64 28: eb b4 jmp 0xffffffffffffffde 2a:* 0f 0b ud2 <-- trapping instruction 2c: 0f b6 54 24 52 movzbl 0x52(%rsp),%edx 31: 48 c7 c7 1c 7e 89 82 mov $0xffffffff82897e1c,%rdi 38: 4c 89 e6 mov %r12,%rsi 3b: 4c 89 e1 mov %r12,%rcx 3e: e8 .byte 0xe8 3f: 43 rex.XB Code starting with the faulting instruction =========================================== 0: 0f 0b ud2 2: 0f b6 54 24 52 movzbl 0x52(%rsp),%edx 7: 48 c7 c7 1c 7e 89 82 mov $0xffffffff82897e1c,%rdi e: 4c 89 e6 mov %r12,%rsi 11: 4c 89 e1 mov %r12,%rcx 14: e8 .byte 0xe8 15: 43 rex.XB [ 0.599197][ T0] RSP: 0000:ffffffff82a03e58 EFLAGS: 00010297 [ 0.599197][ T0] RAX: 0000000000000082 RBX: ffffffff83803d80 RCX: 0000000000000000 [ 0.599197][ T0] RDX: 0000000000000001 RSI: ffffffff81b4e7eb RDI: 00000000000000eb [ 0.599197][ T0] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffffff82a03e58 [ 0.599197][ T0] R10: 000000000000000f R11: 0000000000000040 R12: ffffffff81b4e780 [ 0.599197][ T0] R13: fffffffffe35283c R14: ffffffff837fbf44 R15: ffffffff82a03e58 [ 0.599197][ T0] FS: 0000000000000000(0000) GS:ffff88842fc00000(0000) knlGS:0000000000000000 [ 0.599197][ T0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.599197][ T0] CR2: ffff88843ffff000 CR3: 0000000002a32000 CR4: 00000000000406f0 [ 0.599197][ T0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 0.599197][ T0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 0.599197][ T0] Call Trace: [ 0.599197][ T0] <TASK> [ 0.599197][ T0] ? __die_body (arch/x86/kernel/dumpstack.c:421) [ 0.599197][ T0] ? die (arch/x86/kernel/dumpstack.c:? arch/x86/kernel/dumpstack.c:447) [ 0.599197][ T0] ? do_trap (arch/x86/kernel/traps.c:196) [ 0.599197][ T0] ? apply_direct_call_offset (arch/x86/kernel/alternative.c:302) [ 0.599197][ T0] ? do_error_trap (arch/x86/kernel/traps.c:242) [ 0.599197][ T0] ? apply_direct_call_offset (arch/x86/kernel/alternative.c:302) [ 0.599197][ T0] ? handle_invalid_op (arch/x86/kernel/traps.c:279) [ 0.599197][ T0] ? apply_direct_call_offset (arch/x86/kernel/alternative.c:302) [ 0.599197][ T0] ? exc_invalid_op (arch/x86/kernel/traps.c:361) [ 0.599197][ T0] ? asm_exc_invalid_op (arch/x86/include/asm/idtentry.h:621) [ 0.599197][ T0] ? rtl8169_netpoll (drivers/net/ethernet/realtek/r8169_main.c:4875) [ 0.599197][ T0] ? rtl8169_fix_features (drivers/net/ethernet/realtek/r8169_main.c:1689) [ 0.599197][ T0] ? apply_direct_call_offset (arch/x86/kernel/alternative.c:302) [ 0.599197][ T0] ? apply_direct_call_offset (arch/x86/kernel/alternative.c:885) [ 0.599197][ T0] ? rtl8169_netpoll (drivers/net/ethernet/realtek/r8169_main.c:4875) [ 0.599197][ T0] ? rtl8169_netpoll (drivers/net/ethernet/realtek/r8169_main.c:4875) [ 0.599197][ T0] ? rtl8169_netpoll (drivers/net/ethernet/realtek/r8169_main.c:4875) [ 0.599197][ T0] alternative_instructions (arch/x86/kernel/alternative.c:1822) [ 0.599197][ T0] arch_cpu_finalize_init (arch/x86/kernel/cpu/common.c:2397) [ 0.599197][ T0] start_kernel (init/main.c:1073) [ 0.599197][ T0] x86_64_start_reservations (??:?) [ 0.599197][ T0] x86_64_start_kernel (arch/x86/kernel/head64.c:437) [ 0.599197][ T0] common_startup_64 (arch/x86/kernel/head_64.S:414) [ 0.599197][ T0] </TASK> [ 0.599197][ T0] Modules linked in: [ 0.599201][ T0] ---[ end trace 0000000000000000 ]--- [ 0.600092][ T0] RIP: 0010:apply_direct_call_offset (arch/x86/kernel/alternative.c:302) [ 0.603203][ T0] Code: 04 eb db 83 f8 0f 75 0f 80 7c 24 19 8f 7f 1d 43 83 44 2e 02 04 eb c7 3d eb 00 00 00 74 a3 eb 0c 0f 0b eb ba f3 0f 1e fa eb b4 <0f> 0b 0f b6 54 24 52 48 c7 c7 1c 7e 89 82 4c 89 e6 4c 89 e1 e8 43 All code ======== 0: 04 eb add $0xeb,%al 2: db 83 f8 0f 75 0f fildl 0xf750ff8(%rbx) 8: 80 7c 24 19 8f cmpb $0x8f,0x19(%rsp) d: 7f 1d jg 0x2c f: 43 83 44 2e 02 04 addl $0x4,0x2(%r14,%r13,1) 15: eb c7 jmp 0xffffffffffffffde 17: 3d eb 00 00 00 cmp $0xeb,%eax 1c: 74 a3 je 0xffffffffffffffc1 1e: eb 0c jmp 0x2c 20: 0f 0b ud2 22: eb ba jmp 0xffffffffffffffde 24: f3 0f 1e fa endbr64 28: eb b4 jmp 0xffffffffffffffde 2a:* 0f 0b ud2 <-- trapping instruction 2c: 0f b6 54 24 52 movzbl 0x52(%rsp),%edx 31: 48 c7 c7 1c 7e 89 82 mov $0xffffffff82897e1c,%rdi 38: 4c 89 e6 mov %r12,%rsi 3b: 4c 89 e1 mov %r12,%rcx 3e: e8 .byte 0xe8 3f: 43 rex.XB Code starting with the faulting instruction =========================================== 0: 0f 0b ud2 2: 0f b6 54 24 52 movzbl 0x52(%rsp),%edx 7: 48 c7 c7 1c 7e 89 82 mov $0xffffffff82897e1c,%rdi e: 4c 89 e6 mov %r12,%rsi 11: 4c 89 e1 mov %r12,%rcx 14: e8 .byte 0xe8 15: 43 rex.XB The kernel config and materials to reproduce are available at: https://download.01.org/0day-ci/archive/20241011/202410111436.282a8f8a-lkp@xxxxxxxxx -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki