On Thu, May 05, 2022 at 01:50:01PM +0200, Paolo Abeni wrote:
> On Thu, 2022-05-05 at 14:03 +0300, Dan Carpenter wrote:
> > The mptcp_data_lock/unlock(sk) functions are taking the same spin lock
> > as the lock_sock()/release_sock() functions. So we're already holding
> > the lock at this point and taking it again will lead to a deadlock.
>
> Note that lock_sock() (and release_sock()) releases the relevant
> spinlock before completion. AFAICs the above deadlock is not possible.
>
Oh. Yeah. You're right. I had hard coded into my local copy of Smatch
that it took that lock.
{"lock_sock_nested", LOCK, spin_lock, 0, "&$->sk_lock.slock"},
{"release_sock", UNLOCK, spin_lock, 0, "&$->sk_lock.slock"},
But that's wrong... It drops the lock as you say.
regards,
dan carpenter
