From mboxrd@z Thu Jan 1 00:00:00 1970 From: roopa Subject: Re: [PATCH net-next] bridge: Fix setting a flag in br_fill_ifvlaninfo_range(). Date: Fri, 15 May 2015 12:11:00 -0700 Message-ID: <555644C4.8000401@cumulusnetworks.com> References: <1431700047-22560-1-git-send-email-rami.rosen@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "Rosen, Rami" , "davem@davemloft.net" , "netdev@vger.kernel.org" To: "Arad, Ronen" Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:36200 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753391AbbEOTLC (ORCPT ); Fri, 15 May 2015 15:11:02 -0400 Received: by pabts4 with SMTP id ts4so23668245pab.3 for ; Fri, 15 May 2015 12:11:02 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 5/15/15, 11:45 AM, Arad, Ronen wrote: > >> -----Original Message----- >> From: Rosen, Rami >> Sent: Friday, May 15, 2015 7:27 AM >> To: davem@davemloft.net >> Cc: netdev@vger.kernel.org; roopa@cumulusnetworks.com; Arad, Ronen; Rosen, >> Rami >> Subject: [PATCH net-next] bridge: Fix setting a flag in >> br_fill_ifvlaninfo_range(). >> >> This patch fixes setting of vinfo.flags in the br_fill_ifvlaninfo_range(). The >> assignment of vinfo.flags &= ~BRIDGE_VLAN_INFO_RANGE_BEGIN has no effect >> without >> this patch, as vinfo.flags value is overriden by the >> vinfo.flags = flags | BRIDGE_VLAN_INFO_RANGE_END assignement, which follows >> it immedialtely. >> >> Signed-off-by: Rami Rosen >> --- >> net/bridge/br_netlink.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c >> index 6b67ed3..fec65bb 100644 >> --- a/net/bridge/br_netlink.c >> +++ b/net/bridge/br_netlink.c >> @@ -167,7 +167,7 @@ static int br_fill_ifvlaninfo_range(struct sk_buff *skb, >> u16 vid_start, >> vinfo.flags &= ~BRIDGE_VLAN_INFO_RANGE_BEGIN; >> >> vinfo.vid = vid_end; >> - vinfo.flags = flags | BRIDGE_VLAN_INFO_RANGE_END; >> + vinfo.flags &= flags | BRIDGE_VLAN_INFO_RANGE_END; >> if (nla_put(skb, IFLA_BRIDGE_VLAN_INFO, >> sizeof(vinfo), &vinfo)) >> goto nla_put_failure; > > The first part of " &= flags " has no impact as it reverts vinfo.flags to > just the bits set in the flags argument. This is exactly what > "vinfo.flags &= ~BRIDGE_VLAN_INFO_RANGE_BEGIN" does. > > If original code was intended to indicate that the same flags are used for > both start and end attributes except for the RANGE_BEGIN/RANGE_END flags > it would be sufficient to keep the line that clears RANGE_BEGIN bit and > OR vinfo.flags with RANGE_END for the end attribute: > > vinfo.flags |= BRIDGE_VLAN_INFO_RANGE_END; > > If we want the code to show what is actually been written into each > attribute, the fix should be to just delete the line which clears > RANGE_BEGIN flag. I would prefer the fix to just delete the line that clears RANGE_BEGIN because as you and this patch points out that it is a no-op. > > In either case the code as exists today is working as expected. A fix is > only needed to improve readability. agreed. In any case Acked-by: Roopa Prabhu thanks!