linux-kernel - Re: [PATCH] fs, dlm: Don't leak, don't do pointless NULL checks and use kzalloc

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Date:	Wed, 29 Jun 2011 17:40:56 -0400
From:	David Teigland <teigland@...hat.com>
To:	Jesper Juhl <jj@...osbits.net>
Cc:	linux-kernel@...r.kernel.org, cluster-devel@...hat.com,
	Christine Caulfield <ccaulfie@...hat.com>
Subject: Re: [PATCH] fs, dlm: Don't leak, don't do pointless NULL checks and
 use kzalloc

On Wed, Jun 29, 2011 at 11:09:27PM +0200, Jesper Juhl wrote:
> In fs/dlm/lock.c in the dlm_scan_waiters() function there are 3 small
> issues:
> 
> 1) first time through the loop we allocate memory for 'warned', if we
> then (in the loop) don't take the "if (!warned)" path and loop again,
> the second time through the loop we'll allocate memory again and store
> it to 'warned' without freeing the previous allocation - this leaks
> memory.

I don't think so; num_nodes won't be set to zero.

> 2) There's no need to test the return value of the allocation and do a
> memset if is succeedes. Just use kzalloc() to obtain zeroed memory.

fine

> 3) Since kfree() handles NULL pointers gracefully, the test of
> 'warned' against NULL before the kfree() after the loop is completely
> pointless. Remove it.

fine

ack if you want to push those two out yourself.
Dave
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