Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933551AbbDII5M (ORCPT ); Thu, 9 Apr 2015 04:57:12 -0400 Received: from mail.kernel.org ([198.145.29.136]:43290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933515AbbDII47 (ORCPT ); Thu, 9 Apr 2015 04:56:59 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, karl beldan , Karl Beldan , Al Viro , Eric Dumazet , Arnd Bergmann , Mike Frysinger , netdev@vger.kernel.org, Eric Dumazet , "David S. Miller" , Zefan Li Subject: [PATCH 3.4 140/176] lib/checksum.c: fix carry in csum_tcpudp_nofold Date: Thu, 9 Apr 2015 16:46:28 +0800 Message-Id: <1428569224-23820-140-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1428569028-23762-1-git-send-email-lizf@kernel.org> References: <1428569028-23762-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1871 Lines: 65 From: karl beldan 3.4.107-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit 150ae0e94634714b23919f0c333fee28a5b199d5 upstream. The carry from the 64->32bits folding was dropped, e.g with: saddr=0xFFFFFFFF daddr=0xFF0000FF len=0xFFFF proto=0 sum=1, csum_tcpudp_nofold returned 0 instead of 1. Signed-off-by: Karl Beldan Cc: Al Viro Cc: Eric Dumazet Cc: Arnd Bergmann Cc: Mike Frysinger Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Zefan Li --- lib/checksum.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/lib/checksum.c b/lib/checksum.c index 12dceb2..edbf473 100644 --- a/lib/checksum.c +++ b/lib/checksum.c @@ -47,6 +47,15 @@ static inline unsigned short from32to16(unsigned int x) return x; } +static inline u32 from64to32(u64 x) +{ + /* add up 32-bit and 32-bit for 32+c bit */ + x = (x & 0xffffffff) + (x >> 32); + /* add up carry.. */ + x = (x & 0xffffffff) + (x >> 32); + return (u32)x; +} + static unsigned int do_csum(const unsigned char *buff, int len) { int odd; @@ -193,8 +202,7 @@ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, #else s += (proto + len) << 8; #endif - s += (s >> 32); - return (__force __wsum)s; + return (__force __wsum)from64to32(s); } EXPORT_SYMBOL(csum_tcpudp_nofold); #endif -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/