Re: [PATCH v3 2/2] Bluetooth: fix inconsistent lock state in rfcomm_connect_ind

From: Marcel Holtmann
Date: Thu Jul 29 2021 - 15:53:24 EST


Hi Desmond,

> Commit fad003b6c8e3d ("Bluetooth: Fix inconsistent lock state with
> RFCOMM") fixed a lockdep warning due to sk->sk_lock.slock being
> acquired without disabling softirq while the lock is also used in
> softirq context. This was done by disabling interrupts before calling
> bh_lock_sock in rfcomm_sk_state_change.
>
> Later, this was changed in commit e6da0edc24ee ("Bluetooth: Acquire
> sk_lock.slock without disabling interrupts") to disable softirqs
> only.
>
> However, there is another instance of sk->sk_lock.slock being acquired
> without disabling softirq in rfcomm_connect_ind. This patch fixes this
> by disabling local bh before the call to bh_lock_sock.

back in the days, the packet processing was done in a tasklet, but these days it is done in a workqueue. So shouldn’t this be just converted into a lock_sock(). Am I missing something?

Regards

Marcel