linux-kernel - Re: [PATCH, RFC 2/2] Implement sharing/unsharing of PMDs for FS/DAX

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 linux-cve-announce PHC
Open Source and information security mailing list archives

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

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

Message-ID: <20190612020749.sjpuquzxrprkalfy@box>
Date:   Wed, 12 Jun 2019 05:07:49 +0300
From:   "Kirill A. Shutemov" <kirill@...temov.name>
To:     Larry Bassel <larry.bassel@...cle.com>
Cc:     mike.kravetz@...cle.com, willy@...radead.org,
        dan.j.williams@...el.com, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, linux-nvdimm@...ts.01.org
Subject: Re: [PATCH, RFC 2/2] Implement sharing/unsharing of PMDs for FS/DAX

On Fri, May 24, 2019 at 09:07:11AM -0700, Larry Bassel wrote:
> Again, I don't think this can happen in DAX. The only sharing allowed
> is for FS/DAX/2MiB pagesize.

Hm. I still don't follow. How do you guarantee that DAX actually allocated
continues space for the file on backing storage and you can map it with
PMD page? I believe you don't have such guarantee.


-- 
 Kirill A. Shutemov