From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner+w=401wt.eu-S1754887AbYJGSLt@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1754887AbYJGSLt (ORCPT <rfc822;w@1wt.eu>);
	Tue, 7 Oct 2008 14:11:49 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753479AbYJGSLl
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Tue, 7 Oct 2008 14:11:41 -0400
Received: from casper.infradead.org ([85.118.1.10]:48508 "EHLO
	casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753460AbYJGSLl (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Tue, 7 Oct 2008 14:11:41 -0400
Subject: Re: [BUG] SLOB's krealloc() seems bust
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>,
       Christoph Lameter <cl@linux-foundation.org>,
       linux-mm <linux-mm@kvack.org>, Nick Piggin <nickpiggin@yahoo.com.au>,
       Ingo Molnar <mingo@elte.hu>,
       linux-kernel <linux-kernel@vger.kernel.org>,
       akpm <akpm@linuxfoundation.org>,
       Pekka J Enberg <penberg@cs.helsinki.fi>
In-Reply-To: <alpine.LFD.2.00.0810071053540.3208@nehalem.linux-foundation.org>
References: <1223387841.26330.36.camel@lappy.programming.kicks-ass.net>
	 <48EB6D2C.30806@linux-foundation.org>  <1223391655.13453.344.camel@calx>
	 <1223395846.26330.55.camel@lappy.programming.kicks-ass.net>
	 <1223397455.13453.385.camel@calx>
	 <alpine.LFD.2.00.0810071053540.3208@nehalem.linux-foundation.org>
Content-Type: text/plain
Date: Tue, 07 Oct 2008 20:11:22 +0200
Message-Id: <1223403082.26330.78.camel@lappy.programming.kicks-ass.net>
Mime-Version: 1.0
X-Mailer: Evolution 2.22.3.1 
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, 2008-10-07 at 10:57 -0700, Linus Torvalds wrote:

> Peter - can you check with that
> 
> >  	if (slob_page(sp))
> > -		return ((slob_t *)block - 1)->units + SLOB_UNIT;
> > +		return (((slob_t *)block - 1)->units - 1) * SLOB_UNIT;
> 
> thing using
> 
> -		return ((slob_t *)block - 1)->units + SLOB_UNIT;
> +		return ((slob_t *)block - 1)->units * SLOB_UNIT;
> 
> instead? 

went splat on the second run...