linux-ext4 - Re: [PATCH v6 01/10] mm: add zone device coherent type memory support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 16 Feb 2022 13:28:53 -0400
From:   Jason Gunthorpe <jgg@...dia.com>
To:     Felix Kuehling <felix.kuehling@....com>
Cc:     Christoph Hellwig <hch@....de>,
        David Hildenbrand <david@...hat.com>,
        Alex Sierra <alex.sierra@....com>, akpm@...ux-foundation.org,
        linux-mm@...ck.org, rcampbell@...dia.com,
        linux-ext4@...r.kernel.org, linux-xfs@...r.kernel.org,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        jglisse@...hat.com, apopple@...dia.com, willy@...radead.org
Subject: Re: [PATCH v6 01/10] mm: add zone device coherent type memory support

On Wed, Feb 16, 2022 at 11:56:51AM -0500, Felix Kuehling wrote:

> In the case of DEVICE_COHERENT memory, the pfns correspond to real physical
> memory addresses. I don't think they have those PFN_DEV|PFN_MAP bits set.

So do DAX pages. The PTE flag does several things. As this would be
the first time ZONE_DEVICE pages do not set devmap it needs a full
audit.

eg the gup_fast bug Alistair pointed at needs fixing at least.

Jason