Re: [PATCH net] net: mscc: ocelot: return error if VCAP filter is not found

[David Miller <davem@davemloft.net>]

From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Tue, 22 Sep 2020 02:36:37 +0300

> From: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
> 
> There are 2 separate, but related, issues.
> 
> First, the ocelot_vcap_block_get_filter_index function, née
> ocelot_ace_rule_get_index_id prior to the aae4e500e106 ("net: mscc:
> ocelot: generalize the "ACE/ACL" names") rename, does not do what the
> author probably intended. If the desired filter entry is not present in
> the ACL block, this function returns an index equal to the total number
> of filters, instead of -1, which is maybe what was intended, judging
> from the curious initialization with -1, and the "++index" idioms.
> Either way, none of the callers seems to expect this behavior.
> 
> Second issue, the callers don't actually check the return value at all.
> So in case the filter is not found in the rule list, propagate the
> return code to avoid kernel panics.
> 
> So update the callers and also take the opportunity to get rid of the
> odd coding idioms that appear to work but don't.
> 
> Signed-off-by: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Please repost this with an appropriate Fixes: tag.

Thank you.