From b80a1b80818cd83c6c2109081b43551e7af72c84 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Sat, 20 Sep 2008 17:20:04 +0200 Subject: [PATCH] [MIPS] Fix 64-bit IP checksum code Use unsigned loads to avoid possible misscalculation of IP checksums. This bug was instruced in f761106cd728bcf65b7fe161b10221ee00cf7132 (lmo) / ed99e2bc1dc5dc54eb5a019f4975562dbef20103 (kernel.org). [Original fix by Atsushi. Improved instruction scheduling and fix for unaligned unsigned load by me -- Ralf] Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- arch/mips/lib/csum_partial.S | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/arch/mips/lib/csum_partial.S b/arch/mips/lib/csum_partial.S index 8d7784122c14..edac9892c51a 100644 --- a/arch/mips/lib/csum_partial.S +++ b/arch/mips/lib/csum_partial.S @@ -39,12 +39,14 @@ #ifdef USE_DOUBLE #define LOAD ld +#define LOAD32 lwu #define ADD daddu #define NBYTES 8 #else #define LOAD lw +#define LOAD32 lw #define ADD addu #define NBYTES 4 @@ -60,6 +62,14 @@ ADD sum, v1; \ .set pop +#define ADDC32(sum,reg) \ + .set push; \ + .set noat; \ + addu sum, reg; \ + sltu v1, sum, reg; \ + addu sum, v1; \ + .set pop + #define CSUM_BIGCHUNK1(src, offset, sum, _t0, _t1, _t2, _t3) \ LOAD _t0, (offset + UNIT(0))(src); \ LOAD _t1, (offset + UNIT(1))(src); \ @@ -132,7 +142,7 @@ LEAF(csum_partial) beqz t8, .Lqword_align andi t8, src, 0x8 - lw t0, 0x00(src) + LOAD32 t0, 0x00(src) LONG_SUBU a1, a1, 0x4 ADDC(sum, t0) PTR_ADDU src, src, 0x4 @@ -211,7 +221,7 @@ LEAF(csum_partial) LONG_SRL t8, t8, 0x2 .Lend_words: - lw t0, (src) + LOAD32 t0, (src) LONG_SUBU t8, t8, 0x1 ADDC(sum, t0) .set reorder /* DADDI_WAR */ @@ -230,6 +240,9 @@ LEAF(csum_partial) /* Still a full word to go */ ulw t1, (src) PTR_ADDIU src, 4 +#ifdef USE_DOUBLE + dsll t1, t1, 32 /* clear lower 32bit */ +#endif ADDC(sum, t1) 1: move t1, zero @@ -280,7 +293,7 @@ LEAF(csum_partial) 1: .set reorder /* Add the passed partial csum. */ - ADDC(sum, a2) + ADDC32(sum, a2) jr ra .set noreorder END(csum_partial) @@ -681,7 +694,7 @@ EXC( sb t0, NBYTES-2(dst), .Ls_exc) .set pop 1: .set reorder - ADDC(sum, psum) + ADDC32(sum, psum) jr ra .set noreorder -- 2.20.1