======================================================== WARNING: possible irq lock inversion dependency detected 5.3.0-rc4-next-20190814 #66 Not tainted -------------------------------------------------------- kworker/u4:0/7 just changed the state of lock: ffff88808843fb58 (&(&ctx->ctx_lock)->rlock){..-.}, at: spin_lock_irq include/linux/spinlock.h:363 [inline] ffff88808843fb58 (&(&ctx->ctx_lock)->rlock){..-.}, at: free_ioctx_users+0x2d/0x490 fs/aio.c:618 but this lock took another, SOFTIRQ-unsafe lock in the past: (&fiq->waitq){+.+.} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fiq->waitq); local_irq_disable(); lock(&(&ctx->ctx_lock)->rlock); lock(&fiq->waitq); lock(&(&ctx->ctx_lock)->rlock); *** DEADLOCK *** 5 locks held by kworker/u4:0/7: #0: ffff888216018ba8 ((wq_completion)bat_events){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff888216018ba8 ((wq_completion)bat_events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888216018ba8 ((wq_completion)bat_events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff888216018ba8 ((wq_completion)bat_events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff888216018ba8 ((wq_completion)bat_events){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff888216018ba8 ((wq_completion)bat_events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff888216018ba8 ((wq_completion)bat_events){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2240 #1: ffff8880a989fdc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2244 #2: ffffffff88fa9a80 (rcu_read_lock){....}, at: batadv_nc_process_nc_paths.part.0+0xab/0x3c0 net/batman-adv/network-coding.c:683 #3: ffffffff88fa99c0 (rcu_callback){....}, at: __rcu_reclaim kernel/rcu/rcu.h:210 [inline] #3: ffffffff88fa99c0 (rcu_callback){....}, at: rcu_do_batch kernel/rcu/tree.c:2157 [inline] #3: ffffffff88fa99c0 (rcu_callback){....}, at: rcu_core+0x60e/0x1560 kernel/rcu/tree.c:2377 #4: ffffffff88fa9a00 (rcu_read_lock_sched){....}, at: percpu_ref_call_confirm_rcu lib/percpu-refcount.c:126 [inline] #4: ffffffff88fa9a00 (rcu_read_lock_sched){....}, at: percpu_ref_switch_to_atomic_rcu+0x20e/0x570 lib/percpu-refcount.c:165 the shortest dependencies between 2nd lock and 1st lock: -> (&fiq->waitq){+.+.} { HARDIRQ-ON-W at: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415 fuse_request_queue_background+0x2f8/0x5a0 fs/fuse/dev.c:676 fuse_request_send_background+0x58/0x110 fs/fuse/dev.c:687 cuse_send_init fs/fuse/cuse.c:459 [inline] cuse_channel_open+0x5ba/0x830 fs/fuse/cuse.c:519 misc_open+0x395/0x4c0 drivers/char/misc.c:141 chrdev_open+0x245/0x6b0 fs/char_dev.c:414 do_dentry_open+0x4df/0x1250 fs/open.c:797 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3416 [inline] path_openat+0x10e9/0x4630 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3fe/0x5d0 fs/open.c:1097 __do_sys_openat fs/open.c:1124 [inline] __se_sys_openat fs/open.c:1118 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1118 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe SOFTIRQ-ON-W at: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415 fuse_request_queue_background+0x2f8/0x5a0 fs/fuse/dev.c:676 fuse_request_send_background+0x58/0x110 fs/fuse/dev.c:687 cuse_send_init fs/fuse/cuse.c:459 [inline] cuse_channel_open+0x5ba/0x830 fs/fuse/cuse.c:519 misc_open+0x395/0x4c0 drivers/char/misc.c:141 chrdev_open+0x245/0x6b0 fs/char_dev.c:414 do_dentry_open+0x4df/0x1250 fs/open.c:797 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3416 [inline] path_openat+0x10e9/0x4630 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3fe/0x5d0 fs/open.c:1097 __do_sys_openat fs/open.c:1124 [inline] __se_sys_openat fs/open.c:1118 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1118 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe INITIAL USE at: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] flush_bg_queue+0x1f3/0x3c0 fs/fuse/dev.c:415 fuse_request_queue_background+0x2f8/0x5a0 fs/fuse/dev.c:676 fuse_request_send_background+0x58/0x110 fs/fuse/dev.c:687 cuse_send_init fs/fuse/cuse.c:459 [inline] cuse_channel_open+0x5ba/0x830 fs/fuse/cuse.c:519 misc_open+0x395/0x4c0 drivers/char/misc.c:141 chrdev_open+0x245/0x6b0 fs/char_dev.c:414 do_dentry_open+0x4df/0x1250 fs/open.c:797 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3416 [inline] path_openat+0x10e9/0x4630 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3fe/0x5d0 fs/open.c:1097 __do_sys_openat fs/open.c:1124 [inline] __se_sys_openat fs/open.c:1118 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1118 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe } ... key at: [] __key.45697+0x0/0x40 ... acquired at: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] aio_poll fs/aio.c:1748 [inline] __io_submit_one fs/aio.c:1822 [inline] io_submit_one+0xefa/0x2ef0 fs/aio.c:1859 __do_sys_io_submit fs/aio.c:1918 [inline] __se_sys_io_submit fs/aio.c:1888 [inline] __x64_sys_io_submit+0x1bd/0x570 fs/aio.c:1888 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> (&(&ctx->ctx_lock)->rlock){..-.} { IN-SOFTIRQ-W at: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:363 [inline] free_ioctx_users+0x2d/0x490 fs/aio.c:618 percpu_ref_put_many include/linux/percpu-refcount.h:293 [inline] percpu_ref_put include/linux/percpu-refcount.h:309 [inline] percpu_ref_call_confirm_rcu lib/percpu-refcount.c:130 [inline] percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 lib/percpu-refcount.c:165 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2157 [inline] rcu_core+0x581/0x1560 kernel/rcu/tree.c:2377 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2386 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 debug_lockdep_rcu_enabled+0x71/0xa0 kernel/rcu/update.c:251 rcu_read_unlock include/linux/rcupdate.h:649 [inline] batadv_nc_process_nc_paths.part.0+0x220/0x3c0 net/batman-adv/network-coding.c:698 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:678 [inline] batadv_nc_worker+0x5e4/0x760 net/batman-adv/network-coding.c:734 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INITIAL USE at: lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:363 [inline] aio_poll fs/aio.c:1746 [inline] __io_submit_one fs/aio.c:1822 [inline] io_submit_one+0xeb5/0x2ef0 fs/aio.c:1859 __do_sys_io_submit fs/aio.c:1918 [inline] __se_sys_io_submit fs/aio.c:1888 [inline] __x64_sys_io_submit+0x1bd/0x570 fs/aio.c:1888 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe } ... key at: [] __key.54228+0x0/0x40 ... acquired at: mark_lock_irq kernel/locking/lockdep.c:3317 [inline] mark_lock+0x517/0x1220 kernel/locking/lockdep.c:3666 mark_usage kernel/locking/lockdep.c:3566 [inline] __lock_acquire+0x1eaf/0x4e70 kernel/locking/lockdep.c:3909 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:363 [inline] free_ioctx_users+0x2d/0x490 fs/aio.c:618 percpu_ref_put_many include/linux/percpu-refcount.h:293 [inline] percpu_ref_put include/linux/percpu-refcount.h:309 [inline] percpu_ref_call_confirm_rcu lib/percpu-refcount.c:130 [inline] percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 lib/percpu-refcount.c:165 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2157 [inline] rcu_core+0x581/0x1560 kernel/rcu/tree.c:2377 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2386 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 debug_lockdep_rcu_enabled+0x71/0xa0 kernel/rcu/update.c:251 rcu_read_unlock include/linux/rcupdate.h:649 [inline] batadv_nc_process_nc_paths.part.0+0x220/0x3c0 net/batman-adv/network-coding.c:698 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:678 [inline] batadv_nc_worker+0x5e4/0x760 net/batman-adv/network-coding.c:734 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 stack backtrace: CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.3.0-rc4-next-20190814 #66 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_irq_inversion_bug.part.0+0x2e4/0x2f1 kernel/locking/lockdep.c:3179 print_irq_inversion_bug kernel/locking/lockdep.c:3180 [inline] check_usage_forwards.cold+0x20/0x29 kernel/locking/lockdep.c:3204 mark_lock_irq kernel/locking/lockdep.c:3317 [inline] mark_lock+0x517/0x1220 kernel/locking/lockdep.c:3666 mark_usage kernel/locking/lockdep.c:3566 [inline] __lock_acquire+0x1eaf/0x4e70 kernel/locking/lockdep.c:3909 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x60/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:363 [inline] free_ioctx_users+0x2d/0x490 fs/aio.c:618 percpu_ref_put_many include/linux/percpu-refcount.h:293 [inline] percpu_ref_put include/linux/percpu-refcount.h:309 [inline] percpu_ref_call_confirm_rcu lib/percpu-refcount.c:130 [inline] percpu_ref_switch_to_atomic_rcu+0x4c0/0x570 lib/percpu-refcount.c:165 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2157 [inline] rcu_core+0x581/0x1560 kernel/rcu/tree.c:2377 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2386 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:debug_lockdep_rcu_enabled+0x71/0xa0 kernel/rcu/update.c:253 Code: ff df 48 89 c1 83 e0 07 48 c1 e9 03 83 c0 03 0f b6 14 11 38 d0 7c 04 84 d2 75 23 8b 05 cc e7 67 08 85 c0 74 07 e8 2f ff ff ff <5d> c3 31 c0 5d c3 48 c7 c7 70 41 c6 89 e8 9d 82 4e 00 eb a9 48 c7 RSP: 0018:ffff8880a989fc58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffff8880a0b1b708 RCX: 1ffffffff138ce4e RDX: 0000000000000000 RSI: ffffffff8724ec2b RDI: ffff8880a9890a54 RBP: ffff8880a989fc58 R08: ffff8880a98901c0 R09: ffffed1015d06ad5 R10: ffffed1015d06ad4 R11: ffff8880ae8356a3 R12: 0000000000000000 R13: ffff8880a7a6c500 R14: ffff88808bdc2000 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:649 [inline] batadv_nc_process_nc_paths.part.0+0x220/0x3c0 net/batman-adv/network-coding.c:698 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:678 [inline] batadv_nc_worker+0x5e4/0x760 net/batman-adv/network-coding.c:734 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352