linux-kernel - Re: missing madvise functionality

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:	Wed, 04 Apr 2007 14:08:47 -0400
From:	Rik van Riel <riel@...hat.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
CC:	Hugh Dickins <hugh@...itas.com>, Jakub Jelinek <jakub@...hat.com>,
	Ulrich Drepper <drepper@...hat.com>,
	Andi Kleen <andi@...stfloor.org>,
	Linux Kernel <linux-kernel@...r.kernel.org>, linux-mm@...ck.org
Subject: Re: missing madvise functionality

Andrew Morton wrote:

> There are other ways of doing it - I guess we could use a new page flag to
> indicate that this is one-of-those-pages, and add new code to handle it in
> all the right places.

That's what I did.  I'm currently working on the
zap_page_range() side of things.

> One thing which we haven't sorted out with all this stuff: once the
> application has marked an address range (and some pages) as
> whatever-were-going-call-this-feature, how does the application undo that
> change? 

It doesn't have to do anything.  Just access the page and the
MMU will mark it dirty/accessed and the VM will not reclaim
it.

> What effect will things like mremap, madvise and mlock have upon
> these pages?

Good point.  I had not thought about these.

Would you mind if I sent an initial proof of concept
patch that does not take these into account, before
we decide on what should happen in these cases? :)

-- 
Politics is the struggle between those who want to make their country
the best in the world, and those who believe it already is.  Each group
calls the other unpatriotic.
-
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/