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Date: Mon, 5 Oct 2020 09:52:16 -0300
From: Jason Gunthorpe <jgg@nvidia.com>
To: Jann Horn <jannh@google.com>
CC: Michel Lespinasse <walken@google.com>, Andrew Morton
	<akpm@linux-foundation.org>, linux-mm <linux-mm@kvack.org>, LKML
	<linux-kernel@vger.kernel.org>, "Eric W . Biederman" <ebiederm@xmission.com>,
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Subject: Re: [PATCH 1/2] mmap locking API: Order lock of nascent mm outside
 lock of live mm
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On Mon, Oct 05, 2020 at 03:30:43AM +0200, Jann Horn wrote:
> But another place where lockdep asserts should be added is find_vma();
> there are currently several architectures that sometimes improperly
> call that with no lock held:

Yes, I've seen several cases of this mis-use in drivers too

Jason