From: Greg Kroah-Hartman <gregkh@linuxfoundation•org>
To: linux-kernel@vger•kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
stable@vger•kernel.org,
Karl Beldan <karl.beldan@rivierawaves•com>,
Al Viro <viro@ZenIV•linux.org.uk>,
Eric Dumazet <eric.dumazet@gmail•com>,
Arnd Bergmann <arnd@arndb•de>, Mike Frysinger <vapier@gentoo•org>,
netdev@vger•kernel.org, Eric Dumazet <edumazet@google•com>,
"David S. Miller" <davem@davemloft•net>
Subject: [PATCH 3.10 07/17] lib/checksum.c: fix carry in csum_tcpudp_nofold
Date: Mon, 9 Feb 2015 16:33:34 +0800 [thread overview]
Message-ID: <20150209083040.052922946@linuxfoundation.org> (raw)
In-Reply-To: <20150209083039.240170510@linuxfoundation.org>
3.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: karl beldan <karl.beldan@gmail•com>
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 <karl.beldan@rivierawaves•com>
Cc: Al Viro <viro@ZenIV•linux.org.uk>
Cc: Eric Dumazet <eric.dumazet@gmail•com>
Cc: Arnd Bergmann <arnd@arndb•de>
Cc: Mike Frysinger <vapier@gentoo•org>
Cc: netdev@vger•kernel.org
Cc: linux-kernel@vger•kernel.org
Signed-off-by: Eric Dumazet <edumazet@google•com>
Signed-off-by: David S. Miller <davem@davemloft•net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation•org>
---
lib/checksum.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
--- a/lib/checksum.c
+++ b/lib/checksum.c
@@ -47,6 +47,15 @@ static inline unsigned short from32to16(
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;
@@ -195,8 +204,7 @@ __wsum csum_tcpudp_nofold(__be32 saddr,
#else
s += (proto + len) << 8;
#endif
- s += (s >> 32);
- return (__force __wsum)s;
+ return (__force __wsum)from64to32(s);
}
EXPORT_SYMBOL(csum_tcpudp_nofold);
#endif
parent reply other threads:[~2015-02-09 8:33 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20150209083039.240170510@linuxfoundation.org>]
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