linux-kernel - Re: [PATCH v5 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" 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 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] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAPcyv4gj1E75rZ7kUVfO--CDK_u=-Qci06qmu+cQhaH8V=szGA@mail.gmail.com>
Date:   Fri, 14 Sep 2018 10:40:52 -0700
From:   Dan Williams <dan.j.williams@...el.com>
To:     Christoph Hellwig <hch@....de>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Jérôme Glisse <jglisse@...hat.com>,
        Logan Gunthorpe <logang@...tatee.com>,
        Alexander Duyck <alexander.h.duyck@...el.com>,
        Linux MM <linux-mm@...ck.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v5 2/7] mm, devm_memremap_pages: Kill mapping "System RAM" support

On Fri, Sep 14, 2018 at 6:14 AM, Christoph Hellwig <hch@....de> wrote:
> On Wed, Sep 12, 2018 at 07:22:11PM -0700, Dan Williams wrote:
>> Given the fact that devm_memremap_pages() requires a percpu_ref that is
>> torn down by devm_memremap_pages_release() the current support for
>> mapping RAM is broken.
>
> I agree.  Do you remember why we even added it in the first place?

It was initially a copy over from memremap() that catches these
attempts and returns a direct-map pointer.