PatchSet    : 8540
Branch      : MAIN
Author      : ralf
Date        : 2005/09/20 10:56:26 (1127213786)
Revisions   :
	include/asm-mips/checksum.h : 1.30->1.31
Log:
The type of sum in csum_tcpudp_nofold is "unsigned int", so when we assign
to it in an asm() block, and we're running on a system with 64-bit
registers, it is vitally important that we sign extend it correctly before
returning to C.  Otherwise the stray high bits will be preserved into
csum_fold, and on the SB-1 processor, 32-bit arithmetic on a non
sign-extended register will yield surprising results.

This caused incorrect checksums in some UDP packets for NFS root.  The
problem was mild when using a 10.0.1.x IP address, but severe when
using 192.168.1.x.

Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>


cvs -q -d /home/cvs rdiff -u -kk -r 1.30 -r 1.31 linux/include/asm-mips/checksum.h
Index: linux/include/asm-mips/checksum.h
diff -u linux/include/asm-mips/checksum.h:1.30 linux/include/asm-mips/checksum.h:1.31
--- linux/include/asm-mips/checksum.h:1.30	Thu Jul 14 13:05:08 2005
+++ linux/include/asm-mips/checksum.h	Tue Sep 20 11:56:26 2005
@@ -149,7 +149,7 @@
 	"	daddu	%0, %4		\n"
 	"	dsll32	$1, %0, 0	\n"
 	"	daddu	%0, $1		\n"
-	"	dsrl32	%0, %0, 0	\n"
+	"	dsra32	%0, %0, 0	\n"
 #endif
 	"	.set	pop"
 	: "=r" (sum)