stk1135: probe of 4-1:0.24 failed with error -71 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to enable software MII access usb 4-1: USB disconnect, device number 111 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to read reg index 0x0000: -71 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71 INFO: task kworker/1:4:5540 blocked for more than 143 seconds. asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to enable software MII access Not tainted 5.1.0-rc4-319354-g9a33b36 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:4 D24048 5540 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to read reg index 0x0000: -71 schedule+0x8f/0x180 kernel/sched/core.c:3562 schedule_timeout+0x477/0xdb0 kernel/time/timer.c:1803 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to enable software MII access usb_start_wait_urb.constprop.0+0x2a2/0x2e0 drivers/net/usb/kaweth.c:1250 kaweth_internal_control_msg drivers/net/usb/kaweth.c:1286 [inline] kaweth_control.constprop.0+0x365/0x4f0 drivers/net/usb/kaweth.c:281 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to read reg index 0x0000: -71 kaweth_read_configuration drivers/net/usb/kaweth.c:299 [inline] kaweth_probe.cold+0xb1/0x1359 drivers/net/usb/kaweth.c:1077 usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71 really_probe+0x2da/0xb10 drivers/base/dd.c:509 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to enable software MII access __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to read reg index 0x0000: -71 __device_attach+0x223/0x3a0 drivers/base/dd.c:844 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71 device_add+0xad2/0x16e0 drivers/base/core.c:2106 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to enable software MII access usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021 generic_probe+0xa2/0xda drivers/usb/core/generic.c:210 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to read reg index 0x0000: -71 usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266 really_probe+0x2da/0xb10 drivers/base/dd.c:509 driver_probe_device+0x21d/0x350 drivers/base/dd.c:671 __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778 bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to enable software MII access __device_attach+0x223/0x3a0 drivers/base/dd.c:844 bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to read reg index 0x0000: -71 device_add+0xad2/0x16e0 drivers/base/core.c:2106 usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534 hub_port_connect drivers/usb/core/hub.c:5089 [inline] hub_port_connect_change drivers/usb/core/hub.c:5204 [inline] port_event drivers/usb/core/hub.c:5350 [inline] hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to write reg index 0x0000: -71 process_one_work+0x90f/0x1580 kernel/workqueue.c:2269 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to enable software MII access process_scheduled_works kernel/workqueue.c:2331 [inline] worker_thread+0x7b0/0xe20 kernel/workqueue.c:2417 kthread+0x313/0x420 kernel/kthread.c:253 asix 1-1:0.185 (unnamed net_device) (uninitialized): Failed to read reg index 0x0000: -71 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 usb 2-1: new high-speed USB device number 106 using dummy_hcd Showing all locks held in the system: 5 locks held by kworker/0:1/12: #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81f/0x1580 kernel/workqueue.c:2240 #1: 000000001f4c9517 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x853/0x1580 kernel/workqueue.c:2244 #2: 000000003e87146a (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #2: 000000003e87146a (&dev->mutex){....}, at: hub_event+0x18a/0x3b00 drivers/usb/core/hub.c:5378 #3: 00000000eba188db (&port_dev->status_lock){+.+.}, at: usb_lock_port drivers/usb/core/hub.c:2994 [inline] #3: 00000000eba188db (&port_dev->status_lock){+.+.}, at: hub_port_connect drivers/usb/core/hub.c:5020 [inline] #3: 00000000eba188db (&port_dev->status_lock){+.+.}, at: hub_port_connect_change drivers/usb/core/hub.c:5204 [inline] #3: 00000000eba188db (&port_dev->status_lock){+.+.}, at: port_event drivers/usb/core/hub.c:5350 [inline] #3: 00000000eba188db (&port_dev->status_lock){+.+.}, at: hub_event+0x11a3/0x3b00 drivers/usb/core/hub.c:5432 #4: 000000007e71c6c6 (hcd->address0_mutex){+.+.}, at: hub_port_init+0x1bb/0x2d30 drivers/usb/core/hub.c:4529 6 locks held by kworker/1:1/21: #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81f/0x1580 kernel/workqueue.c:2240 #1: 00000000300627e5 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x853/0x1580 kernel/workqueue.c:2244 #2: 0000000018f45842 (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #2: 0000000018f45842 (&dev->mutex){....}, at: hub_event+0x18a/0x3b00 drivers/usb/core/hub.c:5378 #3: 00000000461bbd6a (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #3: 00000000461bbd6a (&dev->mutex){....}, at: __device_attach+0x80/0x3a0 drivers/base/dd.c:821 #4: 0000000049c78b62 (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #4: 0000000049c78b62 (&dev->mutex){....}, at: __device_attach+0x80/0x3a0 drivers/base/dd.c:821 #5: 000000008764230b (&dev->phy_mutex){+.+.}, at: asix_mdio_read+0x9d/0x2d0 drivers/net/usb/asix_common.c:465 1 lock held by khungtaskd/23: #0: 00000000abd5d395 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:5059 3 locks held by kworker/0:2/533: #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81f/0x1580 kernel/workqueue.c:2240 #1: 000000002e7192e5 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x853/0x1580 kernel/workqueue.c:2244 #2: 0000000069a8b80b (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #2: 0000000069a8b80b (&dev->mutex){....}, at: hub_event+0x18a/0x3b00 drivers/usb/core/hub.c:5378 5 locks held by kworker/1:2/551: #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81f/0x1580 kernel/workqueue.c:2240 #1: 000000004cc7c30c ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x853/0x1580 kernel/workqueue.c:2244 #2: 000000003c5ac933 (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #2: 000000003c5ac933 (&dev->mutex){....}, at: hub_event+0x18a/0x3b00 drivers/usb/core/hub.c:5378 #3: 00000000c69dc599 (&port_dev->status_lock){+.+.}, at: usb_lock_port drivers/usb/core/hub.c:2994 [inline] #3: 00000000c69dc599 (&port_dev->status_lock){+.+.}, at: hub_port_connect drivers/usb/core/hub.c:5020 [inline] #3: 00000000c69dc599 (&port_dev->status_lock){+.+.}, at: hub_port_connect_change drivers/usb/core/hub.c:5204 [inline] #3: 00000000c69dc599 (&port_dev->status_lock){+.+.}, at: port_event drivers/usb/core/hub.c:5350 [inline] #3: 00000000c69dc599 (&port_dev->status_lock){+.+.}, at: hub_event+0x11a3/0x3b00 drivers/usb/core/hub.c:5432 #4: 00000000f25cad65 (hcd->address0_mutex){+.+.}, at: hub_port_init+0x1bb/0x2d30 drivers/usb/core/hub.c:4529 1 lock held by rsyslogd/5303: 2 locks held by getty/5393: #0: 00000000ca5096be (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x27/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000fc84dd4c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21c/0x1a60 drivers/tty/n_tty.c:2156 2 locks held by getty/5394: #0: 00000000450af6aa (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x27/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000004fa33668 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21c/0x1a60 drivers/tty/n_tty.c:2156 2 locks held by getty/5395: #0: 00000000532c4f5a (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x27/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000008ee4d8a5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21c/0x1a60 drivers/tty/n_tty.c:2156 usb 2-1: device descriptor read/64, error 18 2 locks held by getty/5396: #0: 00000000409725cd (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x27/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000b468440f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21c/0x1a60 drivers/tty/n_tty.c:2156 2 locks held by getty/5397: #0: 0000000019d695bc (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x27/0x80 drivers/tty/tty_ldisc.c:272 #1: 0000000009008f2d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21c/0x1a60 drivers/tty/n_tty.c:2156 2 locks held by getty/5398: #0: 000000003539064d (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x27/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000ccc33bf8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21c/0x1a60 drivers/tty/n_tty.c:2156 2 locks held by getty/5399: #0: 00000000ae26695e (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x27/0x80 drivers/tty/tty_ldisc.c:272 usb 4-1: new high-speed USB device number 112 using dummy_hcd #1: 00000000ddde57fb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21c/0x1a60 drivers/tty/n_tty.c:2156 5 locks held by kworker/0:5/5517: #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81f/0x1580 kernel/workqueue.c:2240 #1: 000000002d853ac5 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x853/0x1580 kernel/workqueue.c:2244 #2: 0000000027e13d26 (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #2: 0000000027e13d26 (&dev->mutex){....}, at: hub_event+0x18a/0x3b00 drivers/usb/core/hub.c:5378 #3: 00000000bfc6978a (&port_dev->status_lock){+.+.}, at: usb_lock_port drivers/usb/core/hub.c:2994 [inline] #3: 00000000bfc6978a (&port_dev->status_lock){+.+.}, at: hub_port_connect drivers/usb/core/hub.c:5020 [inline] #3: 00000000bfc6978a (&port_dev->status_lock){+.+.}, at: hub_port_connect_change drivers/usb/core/hub.c:5204 [inline] #3: 00000000bfc6978a (&port_dev->status_lock){+.+.}, at: port_event drivers/usb/core/hub.c:5350 [inline] #3: 00000000bfc6978a (&port_dev->status_lock){+.+.}, at: hub_event+0x11a3/0x3b00 drivers/usb/core/hub.c:5432 #4: 000000002b96a88c (hcd->address0_mutex){+.+.}, at: hub_port_init+0x1bb/0x2d30 drivers/usb/core/hub.c:4529 5 locks held by kworker/1:4/5540: #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 000000000c3766e6 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x81f/0x1580 kernel/workqueue.c:2240 #1: 00000000f4e0839a ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x853/0x1580 kernel/workqueue.c:2244 #2: 00000000bb0b4196 (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #2: 00000000bb0b4196 (&dev->mutex){....}, at: hub_event+0x18a/0x3b00 drivers/usb/core/hub.c:5378 #3: 0000000032c703f3 (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #3: 0000000032c703f3 (&dev->mutex){....}, at: __device_attach+0x80/0x3a0 drivers/base/dd.c:821 #4: 00000000393f4322 (&dev->mutex){....}, at: device_lock include/linux/device.h:1207 [inline] #4: 00000000393f4322 (&dev->mutex){....}, at: __device_attach+0x80/0x3a0 drivers/base/dd.c:821 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 5.1.0-rc4-319354-g9a33b36 #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xe8/0x16e lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x48/0x87 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1bd lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0x98e/0xe20 kernel/hung_task.c:288 kthread+0x313/0x420 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.1.0-rc4-319354-g9a33b36 #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:mark_lock+0x33/0x10d0 kernel/locking/lockdep.c:3388 Code: df 41 57 89 d1 49 89 ff 41 56 4c 8d 76 20 41 55 41 bd 01 00 00 00 41 54 41 89 d4 4c 89 f2 41 d3 e5 55 48 c1 ea 03 48 89 f5 53 <48> 83 ec 18 0f b6 04 02 84 c0 74 08 3c 01 0f 8e 69 06 00 00 0f b7 RSP: 0018:ffff8880a8487b00 EFLAGS: 00000806 RAX: dffffc0000000000 RBX: 0000000000000002 RCX: 0000000000000008 RDX: 1ffff1101508ed56 RSI: ffff8880a8476a90 RDI: ffff8880a8476200 RBP: ffff8880a8476a90 R08: 0000000000000028 R09: 0000000000000028 R10: ffff8880a8476a90 R11: ffff8880a8476200 R12: 0000000000000008 R13: 0000000000000100 R14: ffff8880a8476ab0 R15: ffff8880a8476200 FS: 0000000000000000(0000) GS:ffff8880ad000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000750000 CR3: 000000007eb88000 CR4: 00000000001406f0 Call Trace: __lock_acquire+0x522/0x37c0 kernel/locking/lockdep.c:3657 lock_acquire+0x10d/0x2f0 kernel/locking/lockdep.c:4211 rcu_lock_acquire include/linux/rcupdate.h:210 [inline] rcu_read_lock include/linux/rcupdate.h:595 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:419 [inline] batadv_nc_worker+0x11b/0x770 net/batman-adv/network-coding.c:730 process_one_work+0x90f/0x1580 kernel/workqueue.c:2269 worker_thread+0x9b/0xe20 kernel/workqueue.c:2415 kthread+0x313/0x420 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352