INFO: task kworker/u8:0:11 blocked for more than 143 seconds. Not tainted 6.13.0-rc2-syzkaller-00031-gf92f4749861b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:0 state:D stack:21048 pid:11 tgid:11 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-bcachefs-18) Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 io_schedule+0x8d/0x110 kernel/sched/core.c:7681 folio_wait_bit_common+0x839/0xee0 mm/filemap.c:1308 folio_lock include/linux/pagemap.h:1151 [inline] writeback_get_folio mm/page-writeback.c:2515 [inline] writeback_iter+0x8ad/0x12b0 mm/page-writeback.c:2609 write_cache_pages+0x14d/0x230 mm/page-writeback.c:2658 bch2_writepages+0x156/0x390 fs/bcachefs/fs-io-buffered.c:639 do_writepages+0x35f/0x880 mm/page-writeback.c:2702 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158 wb_check_background_flush fs/fs-writeback.c:2228 [inline] wb_do_writeback fs/fs-writeback.c:2316 [inline] wb_workfn+0xc4b/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task syz.7.237:7786 blocked for more than 144 seconds. Not tainted 6.13.0-rc2-syzkaller-00031-gf92f4749861b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.237 state:D stack:21520 pid:7786 tgid:7757 ppid:7073 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 io_schedule+0x8d/0x110 kernel/sched/core.c:7681 folio_wait_bit_common+0x839/0xee0 mm/filemap.c:1308 folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3194 truncate_inode_partial_folio+0x169/0x5e0 mm/truncate.c:192 truncate_inode_pages_range+0x965/0x10e0 mm/truncate.c:352 bchfs_fpunch+0x1c1/0x780 fs/bcachefs/fs-io.c:514 bch2_fallocate_dispatch+0x3e4/0x540 fs/bcachefs/fs-io.c:782 vfs_fallocate+0x569/0x6e0 fs/open.c:327 ksys_fallocate fs/open.c:351 [inline] __do_sys_fallocate fs/open.c:356 [inline] __se_sys_fallocate fs/open.c:354 [inline] __x64_sys_fallocate+0xbc/0x110 fs/open.c:354 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8f78d7ff19 RSP: 002b:00007f8f79ab1058 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007f8f78f46080 RCX: 00007f8f78d7ff19 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 0000000000000005 RBP: 00007f8f78df3cc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000002328 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8f78f46080 R15: 00007ffd64f443a8 INFO: task syz.7.237:7804 blocked for more than 146 seconds. Not tainted 6.13.0-rc2-syzkaller-00031-gf92f4749861b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.237 state:D stack:27360 pid:7804 tgid:7757 ppid:7073 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578 inode_lock include/linux/fs.h:818 [inline] bch2_write_iter+0x13a/0x2c10 fs/bcachefs/fs-io-buffered.c:1040 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaeb/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8f78d7ff19 RSP: 002b:00007f8f767d3058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f8f78f46240 RCX: 00007f8f78d7ff19 RDX: 000000000000fea0 RSI: 0000000020000040 RDI: 0000000000000006 RBP: 00007f8f78df3cc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8f78f46240 R15: 00007ffd64f443a8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e7e3168 ( wq_pool_mutex ){+.+.}-{4:4} , at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] , at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 8 locks held by kworker/0:0/8: 3 locks held by kworker/u8:0/11: #0: ffff8881436eb948 ( (wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] (wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90000107d00 ( (work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3205 [inline] , at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff88804f7e40e0 ( &type->s_umount_key #72 ){++++}-{4:4} , at: super_trylock_shared+0x22/0xf0 fs/super.c:562 1 lock held by khungtaskd/30: #0: ffffffff8e937ae0 (rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] , at: rcu_read_lock include/linux/rcupdate.h:849 [inline] , at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 3 locks held by kworker/u8:2/35: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90000ab7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000ab7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc9f008 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:281 3 locks held by kworker/u8:5/968: #0: ffff88807fc9a148 ((wq_completion)ext4-rsv-conversion#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88807fc9a148 ((wq_completion)ext4-rsv-conversion#2){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000475fd00 ((work_completion)(&ei->i_rsv_conversion_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000475fd00 ((work_completion)(&ei->i_rsv_conversion_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff8880598fbdf8 ( &ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x7a6/0x1990 fs/ext4/inode.c:701 5 locks held by kworker/u8:6/2994: 4 locks held by udevd/5194: #0: ffff88804f185418 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb4/0xd70 fs/seq_file.c:182 #1: ffff8880121e3088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff88805d203788 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff88804c9b9a20 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff88804c9b9a20 (&dev->mutex){....}-{4:4}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2729 2 locks held by getty/5572: #0: ffff88803207c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:8/5900: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc900040f7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900040f7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc9f008 ( rtnl_mutex ){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 5 locks held by kworker/u8:9/6194: #0: ffff88801baeb148 ( (wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] (wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc900049bfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900049bfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc92b90 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:586 #3: ffffffff8fc9f008 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x6af/0xcc0 net/core/net_namespace.c:622 #4: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 2 locks held by syz.7.237/7758: #0: ffff88806e8e47f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1191 #1: ffff88804f7e4420 (sb_writers#22){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2964 [inline] #1: ffff88804f7e4420 (sb_writers#22){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:675 2 locks held by syz.7.237/7786: #0: ffff88804f7e4420 (sb_writers#22){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2964 [inline] #0: ffff88804f7e4420 (sb_writers#22){.+.+}-{0:0}, at: vfs_fallocate+0x4fe/0x6e0 fs/open.c:326 #1: ffff888059999048 (&sb->s_type->i_mutex_key#29){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline] #1: ffff888059999048 (&sb->s_type->i_mutex_key#29){++++}-{4:4}, at: bch2_fallocate_dispatch+0x1e2/0x540 fs/bcachefs/fs-io.c:771 5 locks held by syz.7.237/7798: #0: ffff88804f7e4420 (sb_writers#22){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff88805999b5c8 (&sb->s_type->i_mutex_key#29){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline] #1: ffff88805999b5c8 (&sb->s_type->i_mutex_key#29){++++}-{4:4}, at: do_truncate+0x20c/0x310 fs/open.c:63 #2: ffff88806fa00a38 (&c->snapshot_create_lock){.+.+}-{4:4}, at: bch2_truncate+0x166/0x2d0 fs/bcachefs/io_misc.c:292 #3: ffff88806fa04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:158 [inline] #3: ffff88806fa04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:249 [inline] #3: ffff88806fa04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7e1/0xd30 fs/bcachefs/btree_iter.c:3228 #4: ffff88806fa266d0 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x682/0x14e0 fs/bcachefs/btree_update_interior.c:1197 3 locks held by syz.7.237/7804: #0: ffff8880333569b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1191 #1: ffff88804f7e4420 (sb_writers#22){.+.+}-{0:0} , at: file_start_write include/linux/fs.h:2964 [inline] , at: vfs_write+0x225/0xd30 fs/read_write.c:675 #2: ffff88805999b5c8 ( &sb->s_type->i_mutex_key#29){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline] &sb->s_type->i_mutex_key#29){++++}-{4:4}, at: bch2_write_iter+0x13a/0x2c10 fs/bcachefs/fs-io-buffered.c:1040 4 locks held by bch-reclaim/loo/7770: #0: ffff88806fa4b0a8 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x167/0x560 fs/bcachefs/journal_reclaim.c:739 #1: ffff88806fa04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:158 [inline] #1: ffff88806fa04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:249 [inline] #1: ffff88806fa04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7e1/0xd30 fs/bcachefs/btree_iter.c:3228 #2: ffff88806fa04740 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x1b19/0x1cc0 fs/bcachefs/btree_write_buffer.c:516 #3: ffff88806fa266d0 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x682/0x14e0 fs/bcachefs/btree_update_interior.c:1197 2 locks held by syz-executor/10831: #0: ffffffff8f448d20 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:555 #1: ffffffff8fc9f008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fc9f008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #1: ffffffff8fc9f008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xbb0/0x20e0 net/core/rtnetlink.c:4008 3 locks held by syz.4.564/10958: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc2-syzkaller-00031-gf92f4749861b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.13.0-rc2-syzkaller-00031-gf92f4749861b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events uhid_device_add_worker RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:409 Code: 20 35 57 fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 e1 0a bb fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c RSP: 0018:ffffc900000d6c78 EFLAGS: 00000002 RAX: 1ffffffff34d7400 RBX: ffffffff9a6ba5e0 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000000 R08: ffffffff854828c6 R09: 1ffff11004aaf046 R10: dffffc0000000000 R11: ffffffff85482880 R12: dffffc0000000000 R13: ffffffff9a3b4f70 R14: 00000000000003fd R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9ebe6a9440 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr drivers/tty/serial/8250/8250_port.c:2087 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3334 [inline] serial8250_console_write+0x1373/0x1ed0 drivers/tty/serial/8250/8250_port.c:3412 console_emit_next_record kernel/printk/printk.c:3122 [inline] console_flush_all+0x869/0xeb0 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432 dev_vprintk_emit+0x2ae/0x330 drivers/base/core.c:4935 dev_printk_emit+0xdd/0x120 drivers/base/core.c:4946 _dev_warn+0x122/0x170 drivers/base/core.c:5002 hid_parser_main+0x71f/0xaa0 drivers/hid/hid-core.c:660 hid_open_report+0xbd8/0x1580 drivers/hid/hid-core.c:1322 hid_parse include/linux/hid.h:1123 [inline] hid_generic_probe+0x3d/0x90 drivers/hid/hid-generic.c:66 __hid_device_probe drivers/hid/hid-core.c:2718 [inline] hid_device_probe+0x3bf/0x710 drivers/hid/hid-core.c:2755 really_probe+0x2b8/0xad0 drivers/base/dd.c:658 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800 driver_probe_device+0x50/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:459 __device_attach+0x333/0x520 drivers/base/dd.c:1030 bus_probe_device+0x189/0x260 drivers/base/bus.c:534 device_add+0x856/0xbf0 drivers/base/core.c:3665 hid_add_device+0x3b6/0x520 drivers/hid/hid-core.c:2901 uhid_device_add_worker+0x44/0xf0 drivers/hid/uhid.c:73 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244