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Date:   Tue, 18 Jun 2019 19:48:21 +0100
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Vicente Bergas <vicencb@gmail.com>
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: d_lookup: Unable to handle kernel paging request
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On Tue, Jun 18, 2019 at 07:35:48PM +0100, Al Viro wrote:

> So far it looks like something is buggering a forward reference
> in hash chain in a fairly specific way - the values seen had been
> 00000000010000000 and
> 00008800010000000.  Does that smell like anything from arm64-specific
> data structures (PTE, etc.)?

make that 0000000001000000 and 0000880001000000 resp.  Tests in the
patch are correct, just mistyped it here...

> Alternatively, we might've gone off rails a step (or more) before,
> with the previous iteration going through bogus, but at least mapped
> address - the one that has never been a dentry in the first place.