From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id c6XYFf1GGVuiOgAAmS7hNA ; Thu, 07 Jun 2018 14:55:09 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 2033D608B8; Thu, 7 Jun 2018 14:55:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id 1BD6D606DD; Thu, 7 Jun 2018 14:55:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 1BD6D606DD Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935452AbeFGOzE (ORCPT + 25 others); Thu, 7 Jun 2018 10:55:04 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41037 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935431AbeFGOzC (ORCPT ); Thu, 7 Jun 2018 10:55:02 -0400 Received: from [148.252.241.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1fQvbO-0005Zs-O2; Thu, 07 Jun 2018 15:09:23 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvbD-0003Gi-FR; Thu, 07 Jun 2018 15:09:11 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Daniel Borkmann" , "David S. Miller" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 372/410] skb: Add skb_postpush_rcsum() In-Reply-To: X-SA-Exim-Connect-IP: 148.252.241.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.57-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings This is based on commit f8ffad69c9f8b8dfb0b633425d4ef4d2493ba61a upstream, "bpf: add skb_postpush_rcsum and fix dev_forward_skb occasions". We don't need the bpf fixes here, just the new function. Cc: Daniel Borkmann Cc: David S. Miller Signed-off-by: Ben Hutchings --- --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2477,6 +2477,23 @@ static inline void skb_postpull_rcsum(st unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); +static inline void skb_postpush_rcsum(struct sk_buff *skb, + const void *start, unsigned int len) +{ + /* For performing the reverse operation to skb_postpull_rcsum(), + * we can instead of ... + * + * skb->csum = csum_add(skb->csum, csum_partial(start, len, 0)); + * + * ... just use this equivalent version here to save a few + * instructions. Feeding csum of 0 in csum_partial() and later + * on adding skb->csum is equivalent to feed skb->csum in the + * first place. + */ + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = csum_partial(start, len, skb->csum); +} + /** * pskb_trim_rcsum - trim received skb and update checksum * @skb: buffer to trim