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authorRalf Baechle <ralf@linux-mips.org>2017-01-26 02:16:47 +0100
committerBen Hutchings <ben@decadent.org.uk>2017-06-05 21:13:49 +0100
commit08b2e7644094195c098ffd2cae7ac5f3281445f0 (patch)
tree0278681f97647f188ab9520899f039bf32800506
parentc0d3aa116fac34a3b39c2f57908aa4788354bf46 (diff)
MIPS: Fix special case in 64 bit IP checksumming.
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>
-rw-r--r--arch/mips/include/asm/checksum.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h
index f2f7c6c264da..9b8401798d8b 100644
--- a/arch/mips/include/asm/checksum.h
+++ b/arch/mips/include/asm/checksum.h
@@ -155,7 +155,9 @@ static inline __wsum csum_tcpudp_nofold(__be32 saddr,
" 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)