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Date: Fri, 23 Mar 2007 08:12:39 -0700 (PDT)
From: Christoph Lameter <clameter@sgi.com>
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To: Stephane Eranian <eranian@hpl.hp.com>
cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, ak@suse.de
Subject: Re: kmalloc() with size zero
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On Thu, 22 Mar 2007, Stephane Eranian wrote:

> I ran into an issue with perfmon where I ended up calling
> kmalloc() with a size of zero. To my surprise, this did
> not return NULL but a valid data address.
> 
> I am wondering if this is a property of kmalloc() or simply
> a bug. It is the case that the __kmalloc() code does not
> check for zero size.

Correct SLAB will give you the smallest possible allocation. I'd say these 
calls should be fixed. SLUB does check for zero and will throw a stack 
dump.