====================================================== WARNING: possible circular locking dependency detected 6.4.0-rc2-syzkaller-00290-gd635f6cc934b #0 Not tainted ------------------------------------------------------ kworker/u17:7/1079 is trying to acquire lock: ffff88807ffdaba0 (&pgdat->kswapd_wait){-.-.}-{2:2}, at: __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 but task is already holding lock: ffff88802c82b858 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline] ffff88802c82b858 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x23e/0xbe0 kernel/time/hrtimer.c:1749 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (hrtimer_bases.lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:173 [inline] hrtimer_start_range_ns+0xe9/0xd80 kernel/time/hrtimer.c:1296 hrtimer_start_expires include/linux/hrtimer.h:432 [inline] do_start_rt_bandwidth kernel/sched/rt.c:116 [inline] start_rt_bandwidth kernel/sched/rt.c:127 [inline] inc_rt_group kernel/sched/rt.c:1241 [inline] inc_rt_tasks kernel/sched/rt.c:1285 [inline] __enqueue_rt_entity kernel/sched/rt.c:1461 [inline] enqueue_rt_entity kernel/sched/rt.c:1510 [inline] enqueue_task_rt+0xa86/0xfc0 kernel/sched/rt.c:1545 enqueue_task+0xad/0x330 kernel/sched/core.c:2082 __sched_setscheduler.constprop.0+0xb89/0x25d0 kernel/sched/core.c:7774 _sched_setscheduler kernel/sched/core.c:7820 [inline] sched_setscheduler_nocheck kernel/sched/core.c:7867 [inline] sched_set_fifo+0xb1/0x110 kernel/sched/core.c:7891 irq_thread+0xe3/0x540 kernel/irq/manage.c:1302 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #3 (&rt_b->rt_runtime_lock){-.-.}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 __enable_runtime kernel/sched/rt.c:876 [inline] rq_online_rt+0xb3/0x3b0 kernel/sched/rt.c:2485 set_rq_online.part.0+0xf9/0x140 kernel/sched/core.c:9541 set_rq_online kernel/sched/core.c:9533 [inline] sched_cpu_activate+0x216/0x440 kernel/sched/core.c:9649 cpuhp_invoke_callback+0x645/0xeb0 kernel/cpu.c:192 cpuhp_thread_fun+0x47f/0x700 kernel/cpu.c:815 smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #2 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x34/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2f/0x120 kernel/sched/core.c:558 raw_spin_rq_lock kernel/sched/sched.h:1366 [inline] rq_lock kernel/sched/sched.h:1653 [inline] task_fork_fair+0x74/0x4f0 kernel/sched/fair.c:12095 sched_cgroup_fork+0x3d1/0x540 kernel/sched/core.c:4777 copy_process+0x4b8a/0x7600 kernel/fork.c:2618 kernel_clone+0xeb/0x890 kernel/fork.c:2918 user_mode_thread+0xb1/0xf0 kernel/fork.c:2996 rest_init+0x27/0x2b0 init/main.c:700 arch_call_rest_init+0x13/0x30 init/main.c:834 start_kernel+0x3b6/0x490 init/main.c:1088 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0xb3/0xc0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0xf4/0xfb -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 try_to_wake_up+0xab/0x1c40 kernel/sched/core.c:4191 autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:419 __wake_up_common+0x147/0x650 kernel/sched/wait.c:107 __wake_up_common_lock+0xd4/0x140 kernel/sched/wait.c:138 wakeup_kswapd+0x3fe/0x5c0 mm/vmscan.c:7798 rmqueue mm/page_alloc.c:3057 [inline] get_page_from_freelist+0x6c5/0x2c00 mm/page_alloc.c:3499 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4768 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] kmem_cache_alloc_node+0x138/0x3e0 mm/slub.c:3496 __alloc_skb+0x288/0x330 net/core/skbuff.c:644 alloc_skb include/linux/skbuff.h:1288 [inline] __tcp_send_ack.part.0+0x67/0x760 net/ipv4/tcp_output.c:3957 __tcp_send_ack net/ipv4/tcp_output.c:3989 [inline] tcp_send_ack+0x81/0xa0 net/ipv4/tcp_output.c:3989 __tcp_ack_snd_check+0x156/0x9e0 net/ipv4/tcp_input.c:5536 tcp_ack_snd_check net/ipv4/tcp_input.c:5582 [inline] tcp_rcv_established+0x912/0x1f90 net/ipv4/tcp_input.c:6022 tcp_v4_do_rcv+0x65a/0x9c0 net/ipv4/tcp_ipv4.c:1722 tcp_v4_rcv+0x30ed/0x3300 net/ipv4/tcp_ipv4.c:2144 ip_protocol_deliver_rcu+0x9f/0x480 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2ec/0x520 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:303 [inline] NF_HOOK include/linux/netfilter.h:297 [inline] ip_local_deliver+0x1ae/0x200 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:468 [inline] ip_sublist_rcv_finish+0x9a/0x2c0 net/ipv4/ip_input.c:580 ip_list_rcv_finish.constprop.0+0x4f9/0x6c0 net/ipv4/ip_input.c:630 ip_sublist_rcv net/ipv4/ip_input.c:638 [inline] ip_list_rcv+0x347/0x4a0 net/ipv4/ip_input.c:673 __netif_receive_skb_list_ptype net/core/dev.c:5534 [inline] __netif_receive_skb_list_core+0x548/0x8f0 net/core/dev.c:5582 __netif_receive_skb_list net/core/dev.c:5634 [inline] netif_receive_skb_list_internal+0x75f/0xdc0 net/core/dev.c:5725 gro_normal_list include/net/gro.h:433 [inline] gro_normal_one include/net/gro.h:446 [inline] napi_skb_finish net/core/gro.c:627 [inline] napi_gro_receive+0x8aa/0xab0 net/core/gro.c:657 e1000_receive_skb drivers/net/ethernet/intel/e1000/e1000_main.c:4008 [inline] e1000_clean_rx_irq+0x50e/0x1010 drivers/net/ethernet/intel/e1000/e1000_main.c:4461 e1000_clean+0x9bf/0x26b0 drivers/net/ethernet/intel/e1000/e1000_main.c:3803 __napi_poll+0xb7/0x6f0 net/core/dev.c:6496 napi_poll net/core/dev.c:6563 [inline] net_rx_action+0x8a9/0xcb0 net/core/dev.c:6696 __do_softirq+0x1d4/0x905 kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:939 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:931 smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #0 (&pgdat->kswapd_wait){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3108 [inline] check_prevs_add kernel/locking/lockdep.c:3227 [inline] validate_chain kernel/locking/lockdep.c:3842 [inline] __lock_acquire+0x2f21/0x5df0 kernel/locking/lockdep.c:5074 lock_acquire kernel/locking/lockdep.c:5691 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 wakeup_kswapd+0x3fe/0x5c0 mm/vmscan.c:7798 wake_all_kswapds+0x182/0x2d0 mm/page_alloc.c:4028 __alloc_pages_slowpath.constprop.0+0x1724/0x2170 mm/page_alloc.c:4296 __alloc_pages+0x408/0x4a0 mm/page_alloc.c:4781 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x38e/0x3b0 mm/slub.c:3475 kmem_cache_zalloc include/linux/slab.h:670 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:168 debug_objects_fill_pool lib/debugobjects.c:597 [inline] debug_object_activate+0xfd/0x400 lib/debugobjects.c:693 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:475 [inline] enqueue_hrtimer+0x27/0x320 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xa5b/0xbe0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 __sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:526 get_random_u8+0x427/0x7d0 drivers/char/random.c:530 get_random_u32_below include/linux/random.h:78 [inline] __nf_conntrack_confirm+0x560/0x1420 net/netfilter/nf_conntrack_core.c:1227 nf_conntrack_confirm include/net/netfilter/nf_conntrack_core.h:62 [inline] nf_confirm+0xf65/0x11c0 net/netfilter/nf_conntrack_proto.c:155 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_slow+0xc9/0x1f0 net/netfilter/core.c:626 nf_hook+0x431/0x730 include/linux/netfilter.h:258 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip6_output+0x334/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:458 [inline] ip6_local_out+0xb3/0x1a0 net/ipv6/output_core.c:155 ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline] udp_tunnel6_xmit_skb+0x740/0xbd0 net/ipv6/ip6_udp_tunnel.c:109 send6+0x48d/0xd00 drivers/net/wireguard/socket.c:152 wg_socket_send_skb_to_peer+0xf9/0x220 drivers/net/wireguard/socket.c:178 wg_socket_send_buffer_to_peer+0x115/0x160 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_initiation+0x20d/0x340 drivers/net/wireguard/send.c:40 wg_packet_handshake_send_worker+0x1c/0x30 drivers/net/wireguard/send.c:51 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 other info that might help us debug this: Chain exists of: &pgdat->kswapd_wait --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hrtimer_bases.lock); lock(&rt_b->rt_runtime_lock); lock(hrtimer_bases.lock); lock(&pgdat->kswapd_wait); *** DEADLOCK *** 8 locks held by kworker/u17:7/1079: #0: ffff88801e7f7138 ((wq_completion)wg-kex-wg0#7){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801e7f7138 ((wq_completion)wg-kex-wg0#7){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88801e7f7138 ((wq_completion)wg-kex-wg0#7){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff88801e7f7138 ((wq_completion)wg-kex-wg0#7){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff88801e7f7138 ((wq_completion)wg-kex-wg0#7){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff88801e7f7138 ((wq_completion)wg-kex-wg0#7){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc90006e7fdb0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 #2: ffff888075f9c2e0 (&peer->endpoint_lock){++..}-{2:2}, at: wg_socket_send_skb_to_peer+0x62/0x220 drivers/net/wireguard/socket.c:173 #3: ffffffff8c798fe0 (rcu_read_lock_bh){....}-{1:2}, at: send6+0x2c8/0xd00 drivers/net/wireguard/socket.c:116 #4: ffffffff8c799040 (rcu_read_lock){....}-{1:2}, at: nf_hook+0x0/0x730 include/linux/skbuff.h:2865 #5: ffffffff8c46ed98 (&nf_conntrack_locks[i]){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] #5: ffffffff8c46ed98 (&nf_conntrack_locks[i]){+.-.}-{2:2}, at: nf_conntrack_lock net/netfilter/nf_conntrack_core.c:107 [inline] #5: ffffffff8c46ed98 (&nf_conntrack_locks[i]){+.-.}-{2:2}, at: nf_conntrack_double_lock.constprop.0+0x4a/0x1c0 net/netfilter/nf_conntrack_core.c:145 #6: ffffffff8c473c98 (&nf_conntrack_locks[i]/1){+.-.}-{2:2}, at: nf_conntrack_double_lock.constprop.0+0x10e/0x1c0 net/netfilter/nf_conntrack_core.c:147 #7: ffff88802c82b858 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline] #7: ffff88802c82b858 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x23e/0xbe0 kernel/time/hrtimer.c:1749 stack backtrace: CPU: 2 PID: 1079 Comm: kworker/u17:7 Not tainted 6.4.0-rc2-syzkaller-00290-gd635f6cc934b #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2188 check_prev_add kernel/locking/lockdep.c:3108 [inline] check_prevs_add kernel/locking/lockdep.c:3227 [inline] validate_chain kernel/locking/lockdep.c:3842 [inline] __lock_acquire+0x2f21/0x5df0 kernel/locking/lockdep.c:5074 lock_acquire kernel/locking/lockdep.c:5691 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 wakeup_kswapd+0x3fe/0x5c0 mm/vmscan.c:7798 wake_all_kswapds+0x182/0x2d0 mm/page_alloc.c:4028 __alloc_pages_slowpath.constprop.0+0x1724/0x2170 mm/page_alloc.c:4296 __alloc_pages+0x408/0x4a0 mm/page_alloc.c:4781 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x38e/0x3b0 mm/slub.c:3475 kmem_cache_zalloc include/linux/slab.h:670 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:168 debug_objects_fill_pool lib/debugobjects.c:597 [inline] debug_object_activate+0xfd/0x400 lib/debugobjects.c:693 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:475 [inline] enqueue_hrtimer+0x27/0x320 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xa5b/0xbe0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:200 Code: f6 d7 8e 02 66 0f 1f 44 00 00 f3 0f 1e fa 48 8b be a8 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1e fa 65 8b 05 ed 78 7f 7e 89 c1 48 8b 34 24 81 e1 00 01 00 RSP: 0018:ffffc90006e7f530 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000000000 RDX: ffff88801ec2c800 RSI: ffffffff848bab81 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000200 R11: 0000000000000020 R12: ffff88802c839300 R13: 1ffff92000dcfeaa R14: 0000000000000002 R15: 0000000000000040 get_random_u8+0x427/0x7d0 drivers/char/random.c:530 get_random_u32_below include/linux/random.h:78 [inline] __nf_conntrack_confirm+0x560/0x1420 net/netfilter/nf_conntrack_core.c:1227 nf_conntrack_confirm include/net/netfilter/nf_conntrack_core.h:62 [inline] nf_confirm+0xf65/0x11c0 net/netfilter/nf_conntrack_proto.c:155 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_slow+0xc9/0x1f0 net/netfilter/core.c:626 nf_hook+0x431/0x730 include/linux/netfilter.h:258 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip6_output+0x334/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:458 [inline] ip6_local_out+0xb3/0x1a0 net/ipv6/output_core.c:155 ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline] udp_tunnel6_xmit_skb+0x740/0xbd0 net/ipv6/ip6_udp_tunnel.c:109 send6+0x48d/0xd00 drivers/net/wireguard/socket.c:152 wg_socket_send_skb_to_peer+0xf9/0x220 drivers/net/wireguard/socket.c:178 wg_socket_send_buffer_to_peer+0x115/0x160 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_initiation+0x20d/0x340 drivers/net/wireguard/send.c:40 wg_packet_handshake_send_worker+0x1c/0x30 drivers/net/wireguard/send.c:51 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 ---------------- Code disassembly (best guess): 0: f6 d7 not %bh 2: 8e 02 mov (%rdx),%es 4: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) a: f3 0f 1e fa endbr64 e: 48 8b be a8 01 00 00 mov 0x1a8(%rsi),%rdi 15: e8 b0 ff ff ff callq 0xffffffca 1a: 31 c0 xor %eax,%eax 1c: c3 retq 1d: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 24: 00 00 00 00 28: 66 90 xchg %ax,%ax * 2a: f3 0f 1e fa endbr64 <-- trapping instruction 2e: 65 8b 05 ed 78 7f 7e mov %gs:0x7e7f78ed(%rip),%eax # 0x7e7f7922 35: 89 c1 mov %eax,%ecx 37: 48 8b 34 24 mov (%rsp),%rsi 3b: 81 .byte 0x81 3c: e1 00 loope 0x3e 3e: 01 00 add %eax,(%rax)