From aa92127b227c6369a78c0fb56ca81dc0399998de Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Mon, 3 Mar 2008 11:47:40 +0000 Subject: [PATCH] x86_emulate: INS/OUTS need Mov attribute to force writeback (since dst.orig_val is not initialised). Also, Mov attribute on cmpxchg is not necessary -- when destination is memory (i.e., successful cmpxchg) then dst.orig_val is already correctly filled in. In case that dst.orig_val == dst.val then the instruction linearises at the point we first read the destination (and initialised dst.orig_val). Signed-off-by: Keir Fraser --- xen/arch/x86/x86_emulate.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/xen/arch/x86/x86_emulate.c b/xen/arch/x86/x86_emulate.c index d75f49c504..a9f60faacf 100644 --- a/xen/arch/x86/x86_emulate.c +++ b/xen/arch/x86/x86_emulate.c @@ -106,7 +106,7 @@ static uint8_t opcode_table[256] = { /* 0x68 - 0x6F */ ImplicitOps|Mov, DstReg|SrcImm|ModRM|Mov, ImplicitOps|Mov, DstReg|SrcImmByte|ModRM|Mov, - ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, + ImplicitOps|Mov, ImplicitOps|Mov, ImplicitOps|Mov, ImplicitOps|Mov, /* 0x70 - 0x77 */ ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, @@ -2862,8 +2862,6 @@ x86_emulate( src.orig_val = src.val; src.val = _regs.eax; emulate_2op_SrcV("cmp", src, dst, _regs.eflags); - /* Always write back. The question is: where to? */ - d |= Mov; if ( _regs.eflags & EFLG_ZF ) { /* Success: write back to memory. */ -- 2.30.2