Re: [PATCH] bridge: Fix return value of br_multicast_add_group()

[Stephen Hemminger <shemminger@linux-foundation.org>]

On Thu,  9 Dec 2010 15:02:36 +0100
Tobias Klauser <tklauser@distanz.ch> wrote:

> If br_multicast_new_group returns NULL, we would return 0 (no error) to
> the caller, which is not what we want. Instead we should return -ENOMEM
> in this case.
> 
> Also replace IS_ERR(x) || !x by IS_ERR_OR_NULL(x)
> 
> Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
> ---
>  net/bridge/br_multicast.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index 326e599..d4e1e81 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -713,8 +713,11 @@ static int br_multicast_add_group(struct net_bridge *br,
>  
>  	mp = br_multicast_new_group(br, port, group);
>  	err = PTR_ERR(mp);
> -	if (unlikely(IS_ERR(mp) || !mp))
> +	if (IS_ERR_OR_NULL(mp)) {
> +		if (!mp)
> +			err = -ENOMEM;
>  		goto err;
> +	}
>  
>  	if (!port) {
>  		hlist_add_head(&mp->mglist, &br->mglist);

I would rather fix br_multicast_new_group so it never returns
NULL. Instead return PTR_ERR(-ENOMEM) on out of memory.

--