linux-kernel - Re: [PATCH] Change ZERO_SIZE_PTR to point at unmapped 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: <20090530230022.GO6535@oblivion.subreption.com>
Date:	Sat, 30 May 2009 16:00:22 -0700
From:	"Larry H." <research@...reption.com>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	linux-mm@...ck.org, Alan Cox <alan@...rguk.ukuu.org.uk>,
	Rik van Riel <riel@...hat.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Change ZERO_SIZE_PTR to point at unmapped space

On 15:29 Sat 30 May     , Linus Torvalds wrote:
> 
> 
> On Sat, 30 May 2009, Larry H. wrote:
> > 
> > The ZERO_OR_NULL_PTR macro is changed accordingly. This patch does
> > not modify its behavior nor has any performance nor functionality
> > impact.
> 
> I'm sure it makes a code generation difference, with (a) big constants and 
> (b) no longer possible to merge the conditional into one single one.

Like I said in the reply to Peter, this is 3 extra bytes for amd64 with
gcc 4.3.3. I can't be bothered to check other architectures at the
moment.

	Larry
--
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/