From 1d892b609b9b8422bad3c98cf1a6d6afafb54c05 Mon Sep 17 00:00:00 2001 From: "kfraser@localhost.localdomain" Date: Wed, 29 Nov 2006 10:48:06 +0000 Subject: [PATCH] [XEN] Emulator fixes. 1. Fix RIP-relative EA calculation. Immediate operands are never 64-bit. 2. Displacements are sign-extended so used signed types. Signed-off-by: Keir Fraser --- xen/arch/x86/x86_emulate.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/xen/arch/x86/x86_emulate.c b/xen/arch/x86/x86_emulate.c index 2ce2dfb440..7fb5875a91 100644 --- a/xen/arch/x86/x86_emulate.c +++ b/xen/arch/x86/x86_emulate.c @@ -615,9 +615,9 @@ x86_emulate_memop( } switch ( modrm_mod ) { - case 0: if ( modrm_rm == 6 ) ea = insn_fetch(uint16_t); break; - case 1: ea += insn_fetch(uint8_t); break; - case 2: ea += insn_fetch(uint16_t); break; + case 0: if ( modrm_rm == 6 ) ea = insn_fetch(int16_t); break; + case 1: ea += insn_fetch(int8_t); break; + case 2: ea += insn_fetch(int16_t); break; } } else @@ -632,7 +632,7 @@ x86_emulate_memop( ea = *(long *)decode_register(sib_index, &_regs, 0); ea <<= (sib >> 6) & 3; if ( (modrm_mod == 0) && ((sib_base & 7) == 5) ) - ea += insn_fetch(uint32_t); + ea += insn_fetch(int32_t); else ea += *(long *)decode_register(sib_base, &_regs, 0); } @@ -646,13 +646,13 @@ x86_emulate_memop( case 0: if ( (modrm_rm & 7) != 5 ) break; - ea = insn_fetch(uint32_t); + ea = insn_fetch(int32_t); if ( mode != X86EMUL_MODE_PROT64 ) break; /* Relative to RIP of next instruction. Argh! */ ea += _regs.eip; if ( (d & SrcMask) == SrcImm ) - ea += (d & ByteOp) ? 1 : op_bytes; + ea += (d & ByteOp) ? 1 : ((op_bytes == 8) ? 4 : op_bytes); else if ( (d & SrcMask) == SrcImmByte ) ea += 1; else if ( ((b == 0xf6) || (b == 0xf7)) && @@ -661,8 +661,8 @@ x86_emulate_memop( ea += (d & ByteOp) ? 1 : ((op_bytes == 8) ? 4 : op_bytes); break; - case 1: ea += insn_fetch(uint8_t); break; - case 2: ea += insn_fetch(uint32_t); break; + case 1: ea += insn_fetch(int8_t); break; + case 2: ea += insn_fetch(int32_t); break; } } -- 2.30.2