From: Atsushi Nemoto Date: Wed, 24 Jan 2007 06:43:34 +0000 (+0900) Subject: [MIPS] Fix wrong checksum calculation on 64-bit MIPS X-Git-Tag: v2.6.20-rc6~1^2 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=66218da212bf141532d678a699f5789c78145ab1;p=linux-2.6-omap-h63xx.git [MIPS] Fix wrong checksum calculation on 64-bit MIPS The commit 8e3d8433d8c22ca6c42cba4a67d300c39aae7822 ([NET]: MIPS checksum annotations and cleanups) broke 64-bit MIPS. The problem is the commit replaces some unsigned long with __be32. On 64bit MIPS, a __be32 (i.e. unsigned int) value is represented as a sign-extented 32-bit value in a 64-bit argument register. So the address 192.168.0.1 (0xc0a80001) is passed as 0xffffffffc0a80001 to csum_tcpudp_nofold() but the asm code in the function expects 0x00000000c0a80001, therefore it returns a wrong checksum. Explicit cast to unsigned long is needed to drop high 32bit. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- diff --git a/include/asm-mips/checksum.h b/include/asm-mips/checksum.h index 24cdcc6eaab..20a81e1548f 100644 --- a/include/asm-mips/checksum.h +++ b/include/asm-mips/checksum.h @@ -159,7 +159,8 @@ static inline __wsum csum_tcpudp_nofold(__be32 saddr, #endif " .set pop" : "=r" (sum) - : "0" (daddr), "r"(saddr), + : "0" ((__force unsigned long)daddr), + "r" ((__force unsigned long)saddr), #ifdef __MIPSEL__ "r" ((proto + len) << 8), #else