KVM: x86 emulator: fix faulty check for two-byte opcode

[linux-2.6-omap-h63xx.git] / drivers / kvm / x86_emulate.c

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 4b8a0cc9665eda6662c5248782ec846e1e6367e7..ef7518a2d7ac7a19531e22e2b42d2df176fd71dc 100644 (file)
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -6,7 +6,7 @@
  * Copyright (c) 2005 Keir Fraser
  *
  * Linux coding style, mod r/m decoder, segment base fixes, real-mode
- * privieged instructions:
+ * privileged instructions:
  *
  * Copyright (C) 2006 Qumranet
  *
@@ -443,8 +443,13 @@ struct operand {
                           (((reg) + _inc) & ((1UL << (ad_bytes << 3)) - 1)); \
        } while (0)
 
-void *decode_register(u8 modrm_reg, unsigned long *regs,
-                     int highbyte_regs)
+/*
+ * Given the 'reg' portion of a ModRM byte, and a register block, return a
+ * pointer into the block that addresses the relevant register.
+ * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
+ */
+static void *decode_register(u8 modrm_reg, unsigned long *regs,
+                            int highbyte_regs)
 {
        void *p;
 
@@ -814,7 +819,7 @@ done_prefixes:
        case DstReg:
                dst.type = OP_REG;
                if ((d & ByteOp)
-                   && !(twobyte_table && (b == 0xb6 || b == 0xb7))) {
+                   && !(twobyte && (b == 0xb6 || b == 0xb7))) {
                        dst.ptr = decode_register(modrm_reg, _regs,
                                                  (rex_prefix == 0));
                        dst.val = *(u8 *) dst.ptr;
@@ -1230,40 +1235,40 @@ twobyte_insn:
                break;
        case 0x40 ... 0x4f:     /* cmov */
                dst.val = dst.orig_val = src.val;
-               d &= ~Mov;      /* default to no move */
+               no_wb = 1;
                /*
                 * First, assume we're decoding an even cmov opcode
                 * (lsb == 0).
                 */
                switch ((b & 15) >> 1) {
                case 0: /* cmovo */
-                       d |= (_eflags & EFLG_OF) ? Mov : 0;
+                       no_wb = (_eflags & EFLG_OF) ? 0 : 1;
                        break;
                case 1: /* cmovb/cmovc/cmovnae */
-                       d |= (_eflags & EFLG_CF) ? Mov : 0;
+                       no_wb = (_eflags & EFLG_CF) ? 0 : 1;
                        break;
                case 2: /* cmovz/cmove */
-                       d |= (_eflags & EFLG_ZF) ? Mov : 0;
+                       no_wb = (_eflags & EFLG_ZF) ? 0 : 1;
                        break;
                case 3: /* cmovbe/cmovna */
-                       d |= (_eflags & (EFLG_CF | EFLG_ZF)) ? Mov : 0;
+                       no_wb = (_eflags & (EFLG_CF | EFLG_ZF)) ? 0 : 1;
                        break;
                case 4: /* cmovs */
-                       d |= (_eflags & EFLG_SF) ? Mov : 0;
+                       no_wb = (_eflags & EFLG_SF) ? 0 : 1;
                        break;
                case 5: /* cmovp/cmovpe */
-                       d |= (_eflags & EFLG_PF) ? Mov : 0;
+                       no_wb = (_eflags & EFLG_PF) ? 0 : 1;
                        break;
                case 7: /* cmovle/cmovng */
-                       d |= (_eflags & EFLG_ZF) ? Mov : 0;
+                       no_wb = (_eflags & EFLG_ZF) ? 0 : 1;
                        /* fall through */
                case 6: /* cmovl/cmovnge */
-                       d |= (!(_eflags & EFLG_SF) !=
-                             !(_eflags & EFLG_OF)) ? Mov : 0;
+                       no_wb &= (!(_eflags & EFLG_SF) !=
+                             !(_eflags & EFLG_OF)) ? 0 : 1;
                        break;
                }
                /* Odd cmov opcodes (lsb == 1) have inverted sense. */
-               d ^= (b & 1) ? Mov : 0;
+               no_wb ^= b & 1;
                break;
        case 0xb0 ... 0xb1:     /* cmpxchg */
                /*