[ 10.074626][ T251]
[ 10.074825][ T251] ============================================
[ 10.075052][ T251] WARNING: possible recursive locking detected
[ 10.075279][ T251] 6.13.0-rc5-virtme #1 Not tainted
[ 10.075462][ T251] --------------------------------------------
[ 10.075680][ T251] busy_poll_test./251 is trying to acquire lock:
[ 10.075902][ T251] ffffffff881f6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x50/0x90
[ 10.076266][ T251]
[ 10.076266][ T251] but task is already holding lock:
[ 10.076539][ T251] ffffffff881f6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x50/0x90
[ 10.076897][ T251]
[ 10.076897][ T251] other info that might help us debug this:
[ 10.077212][ T251] Possible unsafe locking scenario:
[ 10.077212][ T251]
[ 10.077462][ T251] CPU0
[ 10.077588][ T251] ----
[ 10.077712][ T251] lock((netdev_chain).rwsem);
[ 10.077878][ T251] lock((netdev_chain).rwsem);
[ 10.078052][ T251]
[ 10.078052][ T251] *** DEADLOCK ***
[ 10.078052][ T251]
[ 10.078299][ T251] May be due to missing lock nesting notation
[ 10.078299][ T251]
[ 10.078544][ T251] 8 locks held by busy_poll_test./251:
[ 10.078714][ T251] #0: ffff88800b0443f0 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0xf8/0x1d0
[ 10.079017][ T251] #1: ffff88800c148e88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x20b/0x460
[ 10.079320][ T251] #2: ffff888009530910 (kn->active#33){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22e/0x460
[ 10.079656][ T251] #3: ffffffffc060e628 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12a/0x690 [netdevsim]
[ 10.080049][ T251] #4: ffff888005b720e8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x76/0x3f0
[ 10.080354][ T251] #5: ffff888005b73a50 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_probe+0xb7/0x8b0 [netdevsim]
[ 10.080703][ T251] #6: ffffffff88207e88 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x46a/0xa60 [netdevsim]
[ 10.081009][ T251] #7: ffffffff881f6a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x50/0x90
[ 10.081360][ T251]
[ 10.081360][ T251] stack backtrace:
[ 10.081569][ T251] CPU: 0 UID: 0 PID: 251 Comm: busy_poll_test. Not tainted 6.13.0-rc5-virtme #1
[ 10.081858][ T251] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 10.082066][ T251] Call Trace:
[ 10.082194][ T251] <TASK>
[ 10.082283][ T251] dump_stack_lvl+0x82/0xd0
[ 10.082454][ T251] print_deadlock_bug+0x40a/0x650
[ 10.082629][ T251] validate_chain+0x5bf/0xae0
[ 10.082801][ T251] ? __pfx_validate_chain+0x10/0x10
[ 10.082972][ T251] ? hlock_class+0x4e/0x130
[ 10.083138][ T251] ? mark_lock+0x38/0x3e0
[ 10.083267][ T251] __lock_acquire+0xb9a/0x1680
[ 10.083436][ T251] ? udp_tunnel_nic_netdevice_event+0xd1/0x5c0
[ 10.083648][ T251] ? really_probe+0x1df/0x920
[ 10.083816][ T251] lock_acquire.part.0+0xeb/0x330
[ 10.083986][ T251] ? blocking_notifier_call_chain+0x50/0x90
[ 10.084195][ T251] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 10.084403][ T251] ? find_held_lock+0x2c/0x110
[ 10.084569][ T251] ? __pfx_lock_acquire.part.0+0x10/0x10
[ 10.084737][ T251] ? trace_lock_acquire+0x14c/0x1f0
[ 10.084905][ T251] ? lock_acquire+0x32/0xc0
[ 10.085074][ T251] ? blocking_notifier_call_chain+0x50/0x90
[ 10.085287][ T251] down_read+0x9f/0x340
[ 10.085419][ T251] ? blocking_notifier_call_chain+0x50/0x90
[ 10.085628][ T251] ? __pfx_down_read+0x10/0x10
[ 10.085796][ T251] ? notifier_call_chain+0xcd/0x150
[ 10.085966][ T251] blocking_notifier_call_chain+0x50/0x90
[ 10.086136][ T251] call_netdevice_notifiers+0x71/0xa0
[ 10.086306][ T251] ? __pfx_call_netdevice_notifiers+0x10/0x10
[ 10.086519][ T251] ? mutex_is_locked+0x1c/0x60
[ 10.086688][ T251] udp_tunnel_nic_register+0x591/0x870
[ 10.086859][ T251] udp_tunnel_nic_netdevice_event+0x11d/0x5c0
[ 10.087070][ T251] notifier_call_chain+0xcd/0x150
[ 10.087239][ T251] blocking_notifier_call_chain+0x66/0x90
[ 10.087408][ T251] register_netdevice+0xe75/0x1360
[ 10.087581][ T251] ? __pfx_register_netdevice+0x10/0x10
[ 10.087751][ T251] nsim_create+0x6c2/0xa60 [netdevsim]
[ 10.087933][ T251] __nsim_dev_port_add+0x22f/0x6e0 [netdevsim]
[ 10.088150][ T251] ? mark_lock+0x38/0x3e0
[ 10.088279][ T251] ? __pfx___nsim_dev_port_add+0x10/0x10 [netdevsim]
[ 10.088500][ T251] ? lockdep_hardirqs_on_prepare+0x275/0x410
[ 10.088709][ T251] nsim_dev_port_add_all+0x39/0xf0 [netdevsim]
[ 10.088931][ T251] nsim_drv_probe+0x61e/0x8b0 [netdevsim]
[ 10.089110][ T251] ? __pfx_nsim_drv_probe+0x10/0x10 [netdevsim]
[ 10.089328][ T251] ? kernfs_create_link+0x173/0x240
[ 10.089495][ T251] ? kernfs_put+0x1c/0x40
[ 10.089624][ T251] ? sysfs_do_create_link_sd+0x8c/0x100
[ 10.089794][ T251] really_probe+0x1df/0x920
[ 10.089965][ T251] __driver_probe_device+0x2e6/0x3e0
[ 10.090133][ T251] driver_probe_device+0x49/0x140
[ 10.090304][ T251] __device_attach_driver+0x192/0x2b0
[ 10.090472][ T251] ? __pfx___device_attach_driver+0x10/0x10
[ 10.090679][ T251] bus_for_each_drv+0x107/0x1a0
[ 10.090847][ T251] ? __pfx_bus_for_each_drv+0x10/0x10
[ 10.091016][ T251] ? bus_to_subsys+0xd5/0x110
[ 10.091186][ T251] ? __pfx___lock_release+0x10/0x10
[ 10.091363][ T251] ? __pfx_lock_acquire.part.0+0x10/0x10
[ 10.091533][ T251] __device_attach+0x1a3/0x3f0
[ 10.091702][ T251] ? __pfx___device_attach+0x10/0x10
[ 10.091869][ T251] ? bus_to_subsys+0xd5/0x110
[ 10.092035][ T251] ? do_raw_spin_unlock+0x58/0x220
[ 10.092204][ T251] bus_probe_device+0x133/0x180
[ 10.092375][ T251] device_add+0x99d/0x1110
[ 10.092544][ T251] ? __pfx_device_add+0x10/0x10
[ 10.092711][ T251] ? __init_waitqueue_head+0xcf/0x150
[ 10.092884][ T251] new_device_store+0x393/0x690 [netdevsim]
[ 10.093105][ T251] ? __pfx_new_device_store+0x10/0x10 [netdevsim]
[ 10.093326][ T251] ? __pfx_sysfs_kf_write+0x10/0x10
[ 10.093493][ T251] ? sysfs_file_ops+0x11e/0x170
[ 10.093667][ T251] ? __pfx_sysfs_kf_write+0x10/0x10
[ 10.093835][ T251] kernfs_fop_write_iter+0x2ba/0x460
[ 10.094003][ T251] vfs_write+0xa81/0x11e0
[ 10.094131][ T251] ? __pfx_vfs_write+0x10/0x10
[ 10.094299][ T251] ? __lock_release+0x103/0x460
[ 10.094467][ T251] ? do_user_addr_fault+0x972/0xe30
[ 10.094638][ T251] ? __pfx___up_read+0x10/0x10
[ 10.094809][ T251] ksys_write+0xf8/0x1d0
[ 10.094941][ T251] ? __pfx_ksys_write+0x10/0x10
[ 10.095110][ T251] ? do_user_addr_fault+0x97c/0xe30
[ 10.095280][ T251] do_syscall_64+0xc1/0x1d0
[ 10.095451][ T251] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 10.095659][ T251] RIP: 0033:0x7f5f6f90fb77
[ 10.095832][ T251] Code: 0b 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
[ 10.096425][ T251] RSP: 002b:00007ffc632b9fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 10.096676][ T251] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f5f6f90fb77
[ 10.096928][ T251] RDX: 0000000000000004 RSI: 000055fb2d1d9f80 RDI: 0000000000000001
[ 10.097185][ T251] RBP: 000055fb2d1d9f80 R08: 0000000000000003 R09: 0000000000000000
[ 10.097437][ T251] R10: 0000000000000020 R11: 0000000000000246 R12: 0000000000000004
[ 10.097689][ T251] R13: 00007f5f6f9cb760 R14: 0000000000000004 R15: 00007f5f6f9c69c0
[ 10.097944][ T251] </TASK>
[ 10.183989][ T255] netdevsim netdevsim462 eni462np1: renamed from eth0
[ 10.279828][ T254] netdevsim netdevsim546 eni546np1: renamed from eth1