From: karl beldan <karl.bel...@gmail.com> 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 <karl.bel...@rivierawaves.com> Cc: Al Viro <v...@zeniv.linux.org.uk> Cc: Eric Dumazet <eric.duma...@gmail.com> Cc: Arnd Bergmann <a...@arndb.de> Cc: Mike Frysinger <vap...@gentoo.org> Cc: net...@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Eric Dumazet <eduma...@google.com> Signed-off-by: David S. Miller <da...@davemloft.net> Signed-off-by: Zefan Li <lize...@huawei.com> --- 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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/