From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:46832 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932733AbaESR0W (ORCPT ); Mon, 19 May 2014 13:26:22 -0400 Message-ID: <1400520341.3819.15.camel@dcbw.local> (sfid-20140519_192705_138648_0D6B13C5) Subject: Re: [PATCH 1/13] libertas: make return of 0 explicit From: Dan Williams To: Sergei Shtylyov Cc: Julia Lawall , "John W. Linville" , kernel-janitors@vger.kernel.org, libertas-dev@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 19 May 2014 12:25:41 -0500 In-Reply-To: <5379FCD0.2030506@cogentembedded.com> References: <1400473875-22228-1-git-send-email-Julia.Lawall@lip6.fr> <1400473875-22228-2-git-send-email-Julia.Lawall@lip6.fr> <5379FCD0.2030506@cogentembedded.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, 2014-05-19 at 16:45 +0400, Sergei Shtylyov wrote: > Hello. > > On 19-05-2014 8:31, Julia Lawall wrote: > > > From: Julia Lawall > > > Delete unnecessary local variable whose value is always 0 and that hides > > the fact that the result is always 0. > > > A simplified version of the semantic patch that fixes this problem is as > > follows: (http://coccinelle.lip6.fr/) > > > // > > @r exists@ > > local idexpression ret; > > expression e; > > position p; > > @@ > > > > -ret = 0; > > ... when != ret = e > > return > > - ret > > + 0 > > ; > > // > > > Signed-off-by: Julia Lawall > > > --- > > Alternatively, was an error code intended in the bad length case, as is > > done in process_brxed_802_11_packet? > > > drivers/net/wireless/libertas/rx.c | 7 ++----- > > 1 file changed, 2 insertions(+), 5 deletions(-) > > > diff --git a/drivers/net/wireless/libertas/rx.c b/drivers/net/wireless/libertas/rx.c > > index c7366b0..807c5b8 100644 > > --- a/drivers/net/wireless/libertas/rx.c > > +++ b/drivers/net/wireless/libertas/rx.c > [...] > > @@ -154,10 +152,9 @@ int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb) > > else > > netif_rx_ni(skb); > > > > - ret = 0; > > done: > > - lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret); > > - return ret; > > + lbs_deb_leave_args(LBS_DEB_RX, "ret %d", 0); > > Why not just "ret 0"? I think instead we want: diff --git a/drivers/net/wireless/libertas/rx.c b/drivers/net/wireless/libertas/rx.c index c7366b0..e446fed 100644 --- a/drivers/net/wireless/libertas/rx.c +++ b/drivers/net/wireless/libertas/rx.c @@ -67,30 +67,32 @@ int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb) lbs_deb_enter(LBS_DEB_RX); BUG_ON(!skb); skb->ip_summed = CHECKSUM_NONE; - if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) - return process_rxed_802_11_packet(priv, skb); + if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) { + ret = process_rxed_802_11_packet(priv, skb); + goto done; + } p_rx_pd = (struct rxpd *) skb->data; p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd + le32_to_cpu(p_rx_pd->pkt_ptr)); dev = lbs_mesh_set_dev(priv, dev, p_rx_pd); lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min_t(unsigned int, skb->len, 100)); if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) { lbs_deb_rx("rx err: frame received with bad length\n"); dev->stats.rx_length_errors++; - ret = 0; + ret = -EINVAL; dev_kfree_skb(skb); goto done; } lbs_deb_rx("rx data: skb->len - pkt_ptr = %d-%zd = %zd\n", skb->len, (size_t)le32_to_cpu(p_rx_pd->pkt_ptr), skb->len - (size_t)le32_to_cpu(p_rx_pd->pkt_ptr)); Since that (a) preserves the enter/leave balance when monitor mode is enabled, and (b) fixes the return code that has been 0 since the driver was added to the tree in early 2007. Dave Woodhouse fixed the process_rxed_802_11_packet() return code for EINVAL case in commit 7bf02c29 from late 2007, and I think the normal codepath should do EINVAL too. (though it turns out nothing cares about the return code anyway, we should still fix it) Dan