Red Hat Bugzilla – Bug 1429977
workqueue: use rcu_readlock() in put_pwq_unlocked()
Last modified: 2017-08-01 20:25:36 EDT
The RCU sched protection was changed to RCU only and so all IRQ-off and preempt-off disabled region were changed to the relevant rcu-read-lock primitives. One was missed and triggered: |[ BUG: bad unlock balance detected! ] |4.4.30-rt41 #51 Tainted: G W |btattach/345 is trying to release lock ( |Unable to handle kernel paging request at virtual address 6b6b6bbb |Backtrace: |[<c016b5a0>] (lock_release) from [<c0804844>] (rt_spin_unlock+0x20/0x30) |[<c0804824>] (rt_spin_unlock) from [<c0138954>] (put_pwq_unlocked+0xa4/0x118) |[<c01388b0>] (put_pwq_unlocked) from [<c0138b2c>] (destroy_workqueue+0x164/0x1b0) |[<c01389c8>] (destroy_workqueue) from [<c078e1ac>] (hci_unregister_dev+0x120/0x21c) |[<c078e08c>] (hci_unregister_dev) from [<c054f658>] (hci_uart_tty_close+0x90/0xbc) |[<c054f5c8>] (hci_uart_tty_close) from [<c03a2be8>] (tty_ldisc_close+0x50/0x58) |[<c03a2b98>] (tty_ldisc_close) from [<c03a2cb4>] (tty_ldisc_kill+0x18/0x78) |[<c03a2c9c>] (tty_ldisc_kill) from [<c03a3528>] (tty_ldisc_release+0x100/0x134) |[<c03a3428>] (tty_ldisc_release) from [<c039cd68>] (tty_release+0x3bc/0x460) |[<c039c9ac>] (tty_release) from [<c020cc08>] (__fput+0xe0/0x1b4) |[<c020cb28>] (__fput) from [<c020cd3c>] (____fput+0x10/0x14) |[<c020cd2c>] (____fput) from [<c013e0d4>] (task_work_run+0xa4/0xb8) |[<c013e030>] (task_work_run) from [<c0121754>] (do_exit+0x40c/0x8b0) |[<c0121348>] (do_exit) from [<c0122ff8>] (do_group_exit+0x54/0xc4)
Created attachment 1260854 [details] workqueue-use-rcu_readlock-in-put_pwq_unlocked
no reproducer available setting sanityonly
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2017:2077