linux-kernel - Re: Linux 2.6.26-rc1 - pgtable_32.c:178 pmd

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: <alpine.LFD.1.10.0805060807520.32269@woody.linux-foundation.org>
Date:	Tue, 6 May 2008 08:09:35 -0700 (PDT)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Ingo Molnar <mingo@...e.hu>
cc:	Hugh Dickins <hugh@...itas.com>,
	Jeff Chua <jeff.chua.linux@...il.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	Gabriel C <nix.or.die@...glemail.com>,
	Jeremy Fitzhardinge <jeremy@...p.org>
Subject: Re: Linux 2.6.26-rc1 - pgtable_32.c:178 pmd_bad



On Tue, 6 May 2008, Ingo Molnar wrote:
> 
> hm, the main objection was about whether to turn PAGE_SIZE from unsigned 
> into signed though - and that we didnt do.

No it wasn't.

The main objection was that you SHOULD NOT USE PAGE_SIZE_MASK AT ALL!

You should have used a pagetable-specific macro, becuse PAGE_MASK is 
simply fundamentally WRONG, and has absolutely nothing to do with the PFN 
bits, whether sign-extended or not!

The fact is, the page frane number bits are *not* ~PAGE_MASK or anything 
like that. They share only the low bits - not the high bits.

			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/