linux-kernel - Re: [RFC V2] mm:add zero_page _mapcount when mapped into user space

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: <20141202113014.GA22683@node.dhcp.inet.fi>
Date:	Tue, 2 Dec 2014 13:30:14 +0200
From:	"Kirill A. Shutemov" <kirill@...temov.name>
To:	"Wang, Yalin" <Yalin.Wang@...ymobile.com>
Cc:	"'linux-kernel@...r.kernel.org'" <linux-kernel@...r.kernel.org>,
	"'linux-mm@...ck.org'" <linux-mm@...ck.org>,
	"'linux-arm-kernel@...ts.infradead.org'" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [RFC V2] mm:add zero_page _mapcount when mapped into user space

On Tue, Dec 02, 2014 at 05:27:36PM +0800, Wang, Yalin wrote:
> This patch add/dec zero_page's _mapcount to make sure
> the mapcount is correct for zero_page,
> so that when read from /proc/kpagecount, zero_page's
> mapcount is also correct, userspace process like procrank can
> calculate PSS correctly.

I don't have specific code path to point to, but I would expect zero page
with non-zero mapcount would cause a problem with rmap.

How do you test the change?

-- 
 Kirill A. Shutemov
--
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/