Re: possible deadlock in xfrm_policy_delete

On Thu, Sep 24, 2020 at 06:44:12AM +0200, Dmitry Vyukov wrote:

On Thu, Sep 24, 2020 at 6:36 AM Herbert Xu [off-list ref] wrote:

quoted

quoted

 (k-slock-AF_INET6){+.-.}-{2:2}

That's a seqlock.

quoted

What's going on with all these bogus lockdep reports?

These are two completely different locks, one is for TCP and the
other is for SCTP.  Why is lockdep suddenly beoming confused about
this?

FWIW this flood of bogus reports started on 16/Sep.

FWIW one of the dups of this issue was bisected to:

commit 1909760f5fc3f123e47b4e24e0ccdc0fc8f3f106
Author: Ahmed S. Darwish [off-list ref]
Date:   Fri Sep 4 15:32:31 2020 +0000

    seqlock: PREEMPT_RT: Do not starve seqlock_t writers

Can it be related?

Did that tree you're testing include 267580db047e ("seqlock: Unbreak
lockdep") ?