Changeset 103717 in vbox for trunk/src/VBox/Disassembler

Timestamp:

Mar 6, 2024 9:36:59 PM (12 months ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

162085

Message:

DIS: cmpxchg8b/16b fix

Location:

trunk/src/VBox/Disassembler

Files:

• DisasmCore-x86-amd64.cpp (modified) (3 diffs)
• DisasmInternal-x86-amd64.h (modified) (1 diff)
• DisasmTables-x86-amd64.cpp (modified) (1 diff)
• testcase/tstDisasm-1A.asm (modified) (1 diff)

trunk/src/VBox/Disassembler/DisasmCore-x86-amd64.cpp

@@ -2075 +2075 @@
 
     uint8_t const bRm = disReadByte(pDis, offInstr);
-    uint8_t const idx = MODRM_REG(bRm);
+    uint8_t       idx = MODRM_REG(bRm);
     if (MODRM_MOD(bRm) != X86_MOD_REG)
     {
@@ -2086 +2086 @@
         }
         /** @todo bLastPrefix is also set for OP_SEG & OP_ADDRSIZE which aren't relevant here or to any other of the table */
-        else if (pDis->x86.bLastPrefix != OP_LOCK && pDis->x86.bLastPrefix != OP_REPNE)
+        else if (pDis->x86.bLastPrefix != OP_REPNE && (pDis->x86.bLastPrefix != OP_LOCK || idx == 1 /*cmpxchg8/16b*/))
+        {
+            if ((pDis->x86.fRexPrefix & DISPREFIX_REX_FLAGS_W) && (pDis->x86.fPrefix & DISPREFIX_REX))
+                idx += 8;
             pOp = &g_aMapX86_Group9_mem_none[idx];
+        }
         else
             pOp = &g_InvalidOpcode[0];
@@ -2411 +2415 @@
     {
         /* simple: no variations */
-        case OP_CMPXCHG8B: /* == OP_CMPXCHG16B? */
+        case OP_CMPXCHG8B:
+        case OP_CMPXCHG16B:
             return;
 

trunk/src/VBox/Disassembler/DisasmInternal-x86-amd64.h

@@ -201 +201 @@
 extern const DISOPCODE g_aMapX86_Group7_mod11_reg111[8];
 extern const DISOPCODE g_aMapX86_Group8[8];
-extern const DISOPCODE g_aMapX86_Group9_mem_none[8];
+extern const DISOPCODE g_aMapX86_Group9_mem_none[8*2];
 extern const DISOPCODE g_aMapX86_Group9_mem_66[8];
 extern const DISOPCODE g_aMapX86_Group9_mem_f3[8];

trunk/src/VBox/Disassembler/DisasmTables-x86-amd64.cpp

@@ -3118 +3118 @@
 };
 
-/* 0F C7 mode=mem index by /reg - w/o SSE prefix */
-const DISOPCODE g_aMapX86_Group9_mem_none[8] =
-{
+/* 0F C7 mode=mem index by /reg + REX.W*8 - w/o SSE prefix */
+const DISOPCODE g_aMapX86_Group9_mem_none[8 * 2] =
+{
+    /* REX.W = 0 */
     INVALID_OPCODE_MOD_RM(0x0),
-    OP("cmpxchg8b %Mq",      IDX_ParseModRM,     0,          0,          OP_CMPXCHG8B, OP_PARM_Mq,       OP_PARM_NONE,   OP_PARM_NONE,   DISOPTYPE_HARMLESS),
+    OP("cmpxchg8b %Mq",      IDX_ParseModRM,     0,             0,       OP_CMPXCHG8B, OP_PARM_Mq,       OP_PARM_NONE,   OP_PARM_NONE,   DISOPTYPE_HARMLESS),
     INVALID_OPCODE_MOD_RM(0x2),
     INVALID_OPCODE_MOD_RM(0x3),
     INVALID_OPCODE_MOD_RM(0x4),
     INVALID_OPCODE_MOD_RM(0x5),
-    OP("vmptrld %M",         IDX_ParseModRM,     0,             0,       OP_VMPTRLD,   OP_PARM_Mq,       OP_PARM_NONE,   OP_PARM_NONE,   DISOPTYPE_HARMLESS),
-    OP("vmptrst %M",         IDX_ParseModRM,     0,             0,       OP_VMPTRST,   OP_PARM_Mq,       OP_PARM_NONE,   OP_PARM_NONE,   DISOPTYPE_HARMLESS),
+    OP("vmptrld %Mq",        IDX_ParseModRM,     0,             0,       OP_VMPTRLD,   OP_PARM_Mq,       OP_PARM_NONE,   OP_PARM_NONE,   DISOPTYPE_HARMLESS),
+    OP("vmptrst %Mq",        IDX_ParseModRM,     0,             0,       OP_VMPTRST,   OP_PARM_Mq,       OP_PARM_NONE,   OP_PARM_NONE,   DISOPTYPE_HARMLESS),
+    /* REX.W = 1 */
+    INVALID_OPCODE_MOD_RM(0x0),
+    OP("cmpxchg16b %Mdq",    IDX_ParseModRM,     0,             0,       OP_CMPXCHG16B, OP_PARM_Mdq,     OP_PARM_NONE,   OP_PARM_NONE,   DISOPTYPE_HARMLESS),
+    INVALID_OPCODE_MOD_RM(0x2),
+    INVALID_OPCODE_MOD_RM(0x3),
+    INVALID_OPCODE_MOD_RM(0x4),
+    INVALID_OPCODE_MOD_RM(0x5),
+    INVALID_OPCODE_MOD_RM(0x6),
+    INVALID_OPCODE_MOD_RM(0x7),
 };
 

trunk/src/VBox/Disassembler/testcase/tstDisasm-1A.asm

@@ -514 +514 @@
         vmxon [rax]
 
+        cmpxchg8b [rdi]
+        lock cmpxchg8b [rdi]
+        cmpxchg16b [rdi]
+        lock cmpxchg16b [rdi]
+        vmptrst [rsi + 1]
+
         ret
 ENDPROC   TestProc64