From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752970Ab2GWBmW (ORCPT ); Sun, 22 Jul 2012 21:42:22 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53962 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752857Ab2GWBmL (ORCPT ); Sun, 22 Jul 2012 21:42:11 -0400 Message-Id: <20120723010654.135814246@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 23 Jul 2012 02:07:08 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jason Wang , "Michael S. Tsirkin" Subject: [ 017/108] macvtap: zerocopy: fix truesize underestimation In-Reply-To: <20120723010651.408577075@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang commit 4ef67ebedffa44ed9939b34708ac2fee06d2f65f upstream. As the skb fragment were pinned/built from user pages, we should account the page instead of length for truesize. Signed-off-by: Jason Wang Signed-off-by: Michael S. Tsirkin Signed-off-by: Ben Hutchings --- drivers/net/macvtap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index bd4a70d..7cb2684 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -519,6 +519,7 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, struct page *page[MAX_SKB_FRAGS]; int num_pages; unsigned long base; + unsigned long truesize; len = from->iov_len - offset; if (!len) { @@ -533,10 +534,11 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from, (num_pages > MAX_SKB_FRAGS - skb_shinfo(skb)->nr_frags)) /* put_page is in skb free */ return -EFAULT; + truesize = size * PAGE_SIZE; skb->data_len += len; skb->len += len; - skb->truesize += len; - atomic_add(len, &skb->sk->sk_wmem_alloc); + skb->truesize += truesize; + atomic_add(truesize, &skb->sk->sk_wmem_alloc); while (len) { int off = base & ~PAGE_MASK; int size = min_t(int, len, PAGE_SIZE - off);