From: Arvid Brodin Date: Tue, 24 Nov 2015 13:42:41 +0000 Subject: Re: [PATCH] net-hsr: Delete unnecessary checks before the function call "kfree_skb" Message-Id: <56546951.9080101@alten.se> List-Id: References: <5307CAA2.8060406@users.sourceforge.net> <530A086E.8010901@users.sourceforge.net> <530A72AA.3000601@users.sourceforge.net> <530B5FB6.6010207@users.sourceforge.net> <530C5E18.1020800@users.sourceforge.net> <530CD2C4.4050903@users.sourceforge.net> <530CF8FF.8080600@users.sourceforge.net> <530DD06F.4090703@users.sourceforge.net> <5317A59D.4@users.sourceforge.net> <5647A77E.6040501@users.sourceforge.net> In-Reply-To: <5647A77E.6040501@users.sourceforge.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: SF Markus Elfring Cc: "David S. Miller" , netdev@vger.kernel.org, LKML , kernel-janitors@vger.kernel.org, Julia Lawall , Arvid Brodin On 2015-11-14 22:28, SF Markus Elfring wrote: > From: Markus Elfring > Date: Sat, 14 Nov 2015 22:23:48 +0100 > > The kfree_skb() function tests whether its argument is NULL and then > returns immediately. Thus the test around the calls is not needed. > > diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c > index 7871ed6..55ba943 100644 > --- a/net/hsr/hsr_forward.c > +++ b/net/hsr/hsr_forward.c > @@ -355,11 +355,8 @@ void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port) > goto out_drop; > hsr_register_frame_in(frame.node_src, port, frame.sequence_nr); > hsr_forward_do(&frame); > - > - if (frame.skb_hsr != NULL) > - kfree_skb(frame.skb_hsr); > - if (frame.skb_std != NULL) > - kfree_skb(frame.skb_std); > + kfree_skb(frame.skb_hsr); > + kfree_skb(frame.skb_std); Thanks for doing checks on the HSR code, and I apologise for the late reply! Not sure if this has already been applied, but: You're right of course that these checks are not strictly necessary. However, it is likely that at least one of these (.skb_hsr or .skb_std) will be NULL here, so it could be considered nice form to check for this and not just trust kfree_skb() to do this. I'm not sure what's considered more correct in the kernel, so I will just say that I'm agnostic about this and let others decide. Again, thanks! -- Arvid Brodin ALTEN Sweden www.alten.com | www.alten.se