netdev - RE: [PATCH 3/3] dsa: fix freeing of sparse port allocation

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Message-ID: <AE90C24D6B3A694183C094C60CF0A2F6026B71B3@saturn3.aculab.com>
Date:	Mon, 25 Mar 2013 16:03:23 -0000
From:	"David Laight" <David.Laight@...LAB.COM>
To:	"Florian Fainelli" <florian@...nwrt.org>, <davem@...emloft.net>
Cc:	<netdev@...r.kernel.org>
Subject: RE: [PATCH 3/3] dsa: fix freeing of sparse port allocation

> If we have defined a sparse port allocation which is non-contiguous and
> contains gaps, the code freeing port_names will just stop when it
> encouters a first NULL port_names, which is not right, we should iterate
> over all possible number of ports (DSA_MAX_PORTS) until we are done.
...
>  		port_index = 0;
> -		while (pd->chip[i].port_names &&
> -			pd->chip[i].port_names[++port_index])
> -			kfree(pd->chip[i].port_names[port_index]);
> +		while (port_index < DSA_MAX_PORTS) {
> +			if (pd->chip[i].port_names[port_index])
> +				kfree(pd->chip[i].port_names[port_index]);
> +			port_index++;
> +		}

A couple of 'odd' differences:

The old code checked pd->chip[i].port_names (as if it
might be a pointer) that is absent from the new version.
(If it is separately allocated it is leaked).

The new code tests and frees pd->chip[i].port_names[0]
whereas the old code ignored the 0th entry.

These may, or may not, be relevant!

	David



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