linux-kernel - Re: [RFC] Track mlock()ed pages

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 for Android: free password hash cracker in your pocket

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

Message-ID: <45B9ED45.5090002@yahoo.com.au>
Date:	Fri, 26 Jan 2007 23:00:05 +1100
From:	Nick Piggin <nickpiggin@...oo.com.au>
To:	Andrew Morton <akpm@...l.org>
CC:	Christoph Lameter <clameter@....com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC] Track mlock()ed pages

Andrew Morton wrote:
> On Thu, 25 Jan 2007 22:36:17 -0800 (PST)
> Christoph Lameter <clameter@....com> wrote:
> 

>>>I can't think of an easy way to do this without per-page state. ie.
>>>another page flag.
>>
>>Thats what I am trying to avoid.
> 
> 
> You could perhaps go for a walk across all the other vmas which presently
> map this page.  If any of them have VM_LOCKED, don't increment the counter.
> Similar on removal: only decrement the counter when the final mlocked VMA
> is dropping the pte.

Can't do with un-racily because you can't get that information
atomically, AFAIKS. When / if we ever lock the page in fault handler,
this could become easier... but that seems nasty to do in fault path,
even if only for VM_LOCKED vmas.

-- 
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com 
-
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/