linux-kernel - Re: [PATCH] slab: deal with NULL pointers passed to kmem_cache

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Message-ID: <Pine.LNX.4.64.0703191414330.8328@schroedinger.engr.sgi.com>
Date:	Mon, 19 Mar 2007 14:16:01 -0700 (PDT)
From:	Christoph Lameter <clameter@....com>
To:	Matt Mackall <mpm@...enic.com>
cc:	Pekka J Enberg <penberg@...helsinki.fi>, akpm@...ux-foundation.org,
	ast@...dv.de, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] slab: deal with NULL pointers passed to kmem_cache_free

On Mon, 19 Mar 2007, Matt Mackall wrote:

> I think this sort of thing should work:
> 
> a = kmalloc(...)
> b = kmem_cache_alloc(..)
> c = allocate_some_id(...)
> if (!a || !b || !c) {
>    free_some_id(c)
>    kmem_cache_free(c)

^^^^ this requires the specification of a kmem_cache structure and the 
object must be allocated by that cache.

>    kfree(a);

Here we dynamically determine the slab cache and do not verify even which 
slab it came from.

So you can always use kfree if you do not care. kmem_cache_free verifies
correctness.
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