Messages in this thread | | | Subject | Re: [PATCH] datapath: Fix an error handling path in 'ovs_nla_init_match_and_action()' | From | Greg Rose <> | Date | Tue, 12 Sep 2017 15:48:40 -0700 |
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On 09/11/2017 12:20 PM, Christophe JAILLET wrote: > All other error handling paths in this function go through the 'error' > label. This one should do the same. > > Fixes: 9cc9a5cb176c ("datapath: Avoid using stack larger than 1024.") > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > --- > I think that the comment above the function could be improved. It looks > like the commit log which has introduced this function. > > I'm also not sure that commit 9cc9a5cb176c is of any help. It is > supposed to remove a warning, and I guess it does. But 'ovs_nla_init_match_and_action()' > is called unconditionnaly from 'ovs_flow_cmd_set()'. So even if the stack > used by each function is reduced, the overall stack should be the same, if > not larger. > > So this commit sounds like adding a bug where the code was fine and states > to fix an issue but, at the best, only hides it.
Having a large stack frame isn't really a bug per se. But the Linux kernel warns about stack frames that are too large so reordering the code to get the warning to go away seems fine to me.
> > Instead of fixing the code with the proposed patch, reverting the initial > commit could also be considered.
Then the warning will come back.
- Greg
> --- > net/openvswitch/datapath.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c > index 76cf273a56c7..c3aec6227c91 100644 > --- a/net/openvswitch/datapath.c > +++ b/net/openvswitch/datapath.c > @@ -1112,7 +1112,8 @@ static int ovs_nla_init_match_and_action(struct net *net, > if (!a[OVS_FLOW_ATTR_KEY]) { > OVS_NLERR(log, > "Flow key attribute not present in set flow."); > - return -EINVAL; > + error = -EINVAL; > + goto error; > } > > *acts = get_flow_actions(net, a[OVS_FLOW_ATTR_ACTIONS], key, >
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