lkml.org 
[lkml]   [2017]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 3.16 133/212] MIPS: Fix special case in 64 bit IP checksumming.
3.16.44-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ralf Baechle <ralf@linux-mips.org>

commit 66fd848cadaa6be974a8c780fbeb328f0af4d3bd upstream.

For certain arguments such as saddr = 0xc0a8fd60, daddr = 0xc0a8fda1,
len = 80, proto = 17, sum = 0x7eae049d there will be a carry when
folding the intermediate 64 bit checksum to 32 bit but the code doesn't
add the carry back to the one's complement sum, thus an incorrect result
will be generated.

Reported-by: Mark Zhang <bomb.zhang@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/mips/include/asm/checksum.h | 2 ++
1 file changed, 2 insertions(+)

--- a/arch/mips/include/asm/checksum.h
+++ b/arch/mips/include/asm/checksum.h
@@ -185,7 +185,9 @@ static inline __wsum csum_tcpudp_nofold(
" daddu %0, %4 \n"
" dsll32 $1, %0, 0 \n"
" daddu %0, $1 \n"
+ " sltu $1, %0, $1 \n"
" dsra32 %0, %0, 0 \n"
+ " addu %0, $1 \n"
#endif
" .set pop"
: "=r" (sum)
\
 
 \ /
  Last update: 2017-06-01 18:12    [W:1.679 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site