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From:
Vitaliy Makkoveev <mvs@openbsd.org>
Subject:
Re: Push netlock down to ifconf() and move copyout() out of netlock
To:
Janne Johansson <icepic.dz@gmail.com>
Cc:
Alexander Bluhm <bluhm@openbsd.org>, tech@openbsd.org
Date:
Thu, 13 Nov 2025 22:44:44 +0300

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On Thu, Nov 13, 2025 at 07:58:21PM +0100, Janne Johansson wrote:
> Den tors 13 nov. 2025 kl 19:46 skrev Vitaliy Makkoveev <mvs@openbsd.org>:
> >
> > The pagefault handler releases exclusive netlock while copyout(9) needs
> > to load pages from swap. So in the cases like ifconf() netlock protected
> > lists could became inconsistent. Since we use shared netlock, pagefault
> > handler leaves it held, but this breaks swap on NFS. I doubt someone
> > uses swap on NFS, but we hold netlock for unpredictable time.
> 
> I use this at times on my octeons, so please don't break it.
> 

It is broken, this diff fixes it.