INFO: task kworker/u8:7:174 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:7 state:D stack:20488 pid:174 tgid:174 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-btrfs-14)
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
wait_extent_bit fs/btrfs/extent-io-tree.c:811 [inline]
btrfs_lock_extent_bits+0x59c/0x700 fs/btrfs/extent-io-tree.c:1914
btrfs_lock_extent fs/btrfs/extent-io-tree.h:152 [inline]
btrfs_invalidate_folio+0x43d/0xc40 fs/btrfs/inode.c:7685
extent_writepage fs/btrfs/extent_io.c:1852 [inline]
extent_write_cache_pages fs/btrfs/extent_io.c:2580 [inline]
btrfs_writepages+0x12ff/0x2440 fs/btrfs/extent_io.c:2713
do_writepages+0x32e/0x550 mm/page-writeback.c:2554
__writeback_single_inode+0x133/0x11a0 fs/fs-writeback.c:1750
writeback_sb_inodes+0x995/0x19d0 fs/fs-writeback.c:2042
wb_writeback+0x456/0xb70 fs/fs-writeback.c:2227
wb_do_writeback fs/fs-writeback.c:2374 [inline]
wb_workfn+0x41a/0xf60 fs/fs-writeback.c:2414
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.2.111:6663 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.111 state:D stack:21792 pid:6663 tgid:6662 ppid:5797 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
__writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2838
try_to_writeback_inodes_sb+0x9a/0xc0 fs/fs-writeback.c:2886
btrfs_start_delalloc_flush fs/btrfs/transaction.c:2159 [inline]
btrfs_commit_transaction+0x82e/0x31a0 fs/btrfs/transaction.c:2348
__iterate_supers+0x13d/0x290 fs/super.c:927
ksys_sync fs/sync.c:104 [inline]
__ia32_sys_sync+0xbe/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f937be4c799
RSP: 002b:00007f937a09e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f937c0c5fa0 RCX: 00007f937be4c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f937c0c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f937c0c6038 R14: 00007f937c0c5fa0 R15: 00007ffdd0044388
INFO: task syz.4.114:6675 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.114 state:D stack:26944 pid:6675 tgid:6675 ppid:5798 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7286
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x132/0x200 kernel/locking/rwsem.c:1539
btrfs_page_mkwrite+0x60e/0x1b10 fs/btrfs/file.c:1918
do_page_mkwrite+0x150/0x310 mm/memory.c:3589
wp_page_shared mm/memory.c:3990 [inline]
do_wp_page+0x203b/0x49d0 mm/memory.c:4209
handle_pte_fault mm/memory.c:6333 [inline]
__handle_mm_fault mm/memory.c:6455 [inline]
handle_mm_fault+0x9f5/0x13c0 mm/memory.c:6624
do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f0954bab62b
RSP: 002b:00007ffedb64eee8 EFLAGS: 00010202
RAX: 0000200000000100 RBX: 0000000000000004 RCX: 000000000078696e
RDX: 0000000000000006 RSI: 00000000696e696d RDI: 0000200000000100
RBP: fffffffffffffffe R08: 0000001b2df20000 R09: 0000000000000001
R10: 7ffffffffffffff9 R11: 0000000000000009 R12: 00007ffedb64f010
R13: 00007f0954e55fac R14: 0000000000021a78 R15: 00007ffedb64eff0
INFO: task syz.4.114:6676 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.114 state:D stack:22304 pid:6676 tgid:6675 ppid:5798 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
wait_current_trans+0x39f/0x590 fs/btrfs/transaction.c:535
start_transaction+0x6a7/0x1650 fs/btrfs/transaction.c:705
clone_copy_inline_extent fs/btrfs/reflink.c:299 [inline]
btrfs_clone+0x128a/0x24d0 fs/btrfs/reflink.c:529
btrfs_clone_files+0x271/0x3f0 fs/btrfs/reflink.c:750
btrfs_remap_file_range+0x76b/0x1320 fs/btrfs/reflink.c:903
vfs_copy_file_range+0xda7/0x1390 fs/read_write.c:1600
__do_sys_copy_file_range fs/read_write.c:1683 [inline]
__se_sys_copy_file_range+0x2fb/0x480 fs/read_write.c:1650
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0954bdc799
RSP: 002b:00007f0952e36028 EFLAGS: 00000246 ORIG_RAX: 0000000000000146
RAX: ffffffffffffffda RBX: 00007f0954e55fa0 RCX: 00007f0954bdc799
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f0954c72c99 R08: 0000000000000863 R09: 0000000000000000
R10: 00002000000000c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0954e56038 R14: 00007f0954e55fa0 R15: 00007ffedb64ed88
Showing all locks held in the system:
3 locks held by kworker/0:0/9:
#0: ffff888019c03938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888019c03938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc900000e7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc900000e7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffff88802a76c260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490
4 locks held by kworker/u8:1/13:
#0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90000127c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffffffff8f14b940 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
#3: ffffffff8f15a0f8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#3: ffffffff8f15a0f8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248
1 lock held by khungtaskd/37:
#0: ffffffff8ddcb880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:3/56:
#0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc9000122fc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000122fc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
3 locks held by kworker/u9:0/60:
#0: ffff888063a78938 ((wq_completion)hci7){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888063a78938 ((wq_completion)hci7){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc9000126fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc9000126fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffff8880607ccf80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
2 locks held by kworker/u8:7/174:
#0: ffff88801f2e7138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88801f2e7138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90003c97c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90003c97c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
2 locks held by getty/5552:
#0: ffff8880337aa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:4/5838:
#0: ffff888019c03938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888019c03938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90004587c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90004587c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffffffff8f15a0f8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
4 locks held by syz.2.111/6663:
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff88806b53b118 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x41b/0xc90 fs/btrfs/transaction.c:298
#2: ffff88806b53b140 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x41b/0xc90 fs/btrfs/transaction.c:298
#3: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: try_to_writeback_inodes_sb+0x22/0xc0 fs/fs-writeback.c:2883
3 locks held by syz.4.114/6675:
#0: ffff88802ba2f6c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
#1: ffff88803aff05f8 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x150/0x310 mm/memory.c:3589
#2: ffff88804092ade8 (&ei->i_mmap_lock){++++}-{4:4}, at: btrfs_page_mkwrite+0x60e/0x1b10 fs/btrfs/file.c:1918
4 locks held by syz.4.114/6676:
#0: ffff88803aff0480 (sb_writers#24){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff88803aff0480 (sb_writers#24){.+.+}-{0:0}, at: vfs_copy_file_range+0x9bb/0x1390 fs/read_write.c:1588
#1: ffff88804092af88 (&sb->s_type->i_mutex_key#32){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#1: ffff88804092af88 (&sb->s_type->i_mutex_key#32){++++}-{4:4}, at: btrfs_inode_lock+0x51/0xe0 fs/btrfs/inode.c:369
#2: ffff88804092ade8 (&ei->i_mmap_lock){++++}-{4:4}, at: btrfs_inode_lock+0xcb/0xe0 fs/btrfs/inode.c:372
#3: ffff88803aff0770 (sb_internal#4){.+.+}-{0:0}, at: clone_copy_inline_extent fs/btrfs/reflink.c:299 [inline]
#3: ffff88803aff0770 (sb_internal#4){.+.+}-{0:0}, at: btrfs_clone+0x128a/0x24d0 fs/btrfs/reflink.c:529
1 lock held by btrfs-transacti/6718:
#0: ffff88806b538d98 (&fs_info->transaction_kthread_mutex){+.+.}-{4:4}, at: transaction_kthread+0xe4/0x450 fs/btrfs/disk-io.c:1515
2 locks held by syz.3.240/7849:
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff888029bf88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff888029bf88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2922
2 locks held by syz.0.242/8370:
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff888029bf88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff888029bf88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2922
2 locks held by syz.0.242/8371:
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff888029bf88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff888029bf88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2922
2 locks held by syz.0.242/8374:
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88803aff00d0 (&type->s_umount_key#66){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff888029bf88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff888029bf88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2922
1 lock held by syz.9.364/9113:
2 locks held by syz.2.365/9127:
2 locks held by cmp/9150:
7 locks held by udevd/9151:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 28 Comm: rcuc/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
RIP: 0010:slab_free_after_rcu_debug+0x96/0x220 mm/slub.c:6229
Code: 81 f9 00 00 20 00 0f 93 c1 48 85 c0 0f 94 c0 08 c8 0f 84 e7 00 00 00 4d 85 e4 0f 84 e4 00 00 00 4d 8b 7c 24 08 41 f6 47 09 02 <0f> 84 da 00 00 00 0f 1f 44 00 00 31 ed 41 8b 77 1c 48 89 df e8 d1
RSP: 0018:ffffc90000a2fba0 EFLAGS: 00000202
RAX: ffff88823be00001 RBX: ffff88805ad89900 RCX: fffffffe1ef89901
RDX: 0000000000000003 RSI: ffffffff8d55f238 RDI: ffffffff8ba65f80
RBP: ffffc90000a2fd78 R08: ffffffff8f6a31b7 R09: 1ffffffff1ed4636
R10: dffffc0000000000 R11: fffffbfff1ed4637 R12: ffffea00016b6240
R13: dffffc0000000000 R14: ffffea00016b6240 R15: ffff88801b2a0140
FS: 0000000000000000(0000) GS:ffff88812643f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0532bc4e9c CR3: 0000000034b14000 CR4: 00000000003526f0
Call Trace:
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core kernel/rcu/tree.c:2869 [inline]
rcu_cpu_kthread+0x99e/0x1470 kernel/rcu/tree.c:2957
smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245