From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1032819Ab2I1Uah (ORCPT ); Fri, 28 Sep 2012 16:30:37 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:34785 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964981Ab2I1Uaa (ORCPT ); Fri, 28 Sep 2012 16:30:30 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Jason Wang , "Michael S. Tsirkin" , Ben Hutchings Subject: [ 167/218] macvtap: zerocopy: fix offset calculation when building skb Date: Fri, 28 Sep 2012 13:16:24 -0700 Message-Id: <20120928201520.679250618@linuxfoundation.org> X-Mailer: git-send-email 1.7.12.1.428.g652398a In-Reply-To: <20120928201501.208384923@linuxfoundation.org> References: <20120928201501.208384923@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang commit 3afc9621f15701c557e60f61eba9242bac2771dd upstream. This patch fixes the offset calculation when building skb: - offset1 were used as skb data offset not vector offset - reset offset to zero only when we advance to next vector Signed-off-by: Jason Wang Signed-off-by: Michael S. Tsirkin Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/net/macvtap.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -506,10 +506,11 @@ static int zerocopy_sg_from_iovec(struct if (copy > size) { ++from; --count; - } + offset = 0; + } else + offset += size; copy -= size; offset1 += size; - offset = 0; } if (len == offset1) @@ -520,13 +521,13 @@ static int zerocopy_sg_from_iovec(struct int num_pages; unsigned long base; - len = from->iov_len - offset1; + len = from->iov_len - offset; if (!len) { - offset1 = 0; + offset = 0; ++from; continue; } - base = (unsigned long)from->iov_base + offset1; + base = (unsigned long)from->iov_base + offset; size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT; if (i + size > MAX_SKB_FRAGS) return -EMSGSIZE; @@ -548,7 +549,7 @@ static int zerocopy_sg_from_iovec(struct len -= size; i++; } - offset1 = 0; + offset = 0; ++from; } return 0;