From: karl beldan <[email protected]> 3.12-stable 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 <[email protected]> Cc: Al Viro <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Mike Frysinger <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> --- lib/checksum.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/lib/checksum.c b/lib/checksum.c index 129775eb6de6..fcf38943132c 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; @@ -195,8 +204,7 @@ __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 -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
