linux-kernel - Re: [PATCH 2/2] cuse: implement memory mapping

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]

Date:	Fri, 13 Jan 2012 10:19:50 -0800
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Miklos Szeredi <miklos@...redi.hu>
Cc:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	alsa-devel@...a-project.org, htejun@...il.com,
	david.henningsson@...onical.com, smcnam@...il.com,
	gmane@...in.guthr.ie, jamescaldwell1@...il.com,
	s.maddox@...tizia.me.uk, mszeredi@...e.cz
Subject: Re: [PATCH 2/2] cuse: implement memory mapping

On Fri, Jan 13, 2012 at 9:06 AM, Miklos Szeredi <miklos@...redi.hu> wrote:
> From: Tejun Heo <htejun@...il.com>
>
> This implements memory mapping of char devices.

I don't think this is how you want to do it.

It seems to maintain a page list of its own, and do the magic page
fault etc behavior. Which to me smells like a really bad design.

I would expect that what you actually want to do is to expose it as a
shared mmap, and depend on all the normal shmem support. Is there any
reason not to do that?

I guess you don't generally have big mappings, so an argument like
"that way you can page out pages etc" may not strike you as a very
strong argument, but I'd still prefer to at least see that approach
explored. Hmm?

                     Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/