ioq3/code/qcommon/vm_x86.c
Thilo Schulz 4b1418c4ad - Implement opStack protection: Use register %ebx for scaled indexed addressing mode to access opStack, make opStack push/pop operate on %bl portion only
- Add a third pass to VM compilation for computation of jump address offsets, removing the need to dereference into vm->instructionPointers[] for every call/jump
- Make use of 0F opcode prefix relative jumps
- Call Com_Memcpy for OP_BLOCK_COPY
- Fix several missing range checks for vm->dataBase memory access
2011-05-23 00:46:46 +00:00

1626 lines
40 KiB
C

/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
This file is part of Quake III Arena source code.
Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.
Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
// vm_x86.c -- load time compiler and execution environment for x86
#include "vm_local.h"
#ifdef _WIN32
#include <windows.h>
#endif
#ifdef __FreeBSD__
#include <sys/types.h>
#endif
#ifndef _WIN32
#include <sys/mman.h> // for PROT_ stuff
#endif
/* need this on NX enabled systems (i386 with PAE kernel or
* noexec32=on x86_64) */
#if defined(__linux__) || defined(__FreeBSD__)
#define VM_X86_MMAP
#endif
static void VM_Destroy_Compiled(vm_t* self);
/*
eax scratch
ebx/bl opStack offset
ecx scratch (required for shifts)
edx scratch (required for divisions)
esi program stack
edi opStack base
*/
#define VMFREE_BUFFERS() do {Z_Free(buf); Z_Free(jused);} while(0)
static byte *buf = NULL;
static byte *jused = NULL;
static int jusedSize = 0;
static int compiledOfs = 0;
static byte *code = NULL;
static int pc = 0;
#define FTOL_PTR
#ifdef _MSC_VER
#if defined( FTOL_PTR )
int _ftol( float );
static int ftolPtr = (int)_ftol;
#endif
#else // _MSC_VER
#if defined( FTOL_PTR )
int qftol( void );
int qftol027F( void );
int qftol037F( void );
int qftol0E7F( void );
int qftol0F7F( void );
static int ftolPtr = (int)qftol0F7F;
#endif // FTOL_PTR
#endif
static int instruction, pass;
static int lastConst = 0;
static int oc0, oc1, pop0, pop1;
static int jlabel;
typedef enum
{
LAST_COMMAND_NONE = 0,
LAST_COMMAND_MOV_STACK_EAX,
LAST_COMMAND_SUB_BL_1,
LAST_COMMAND_SUB_BL_2,
} ELastCommand;
typedef enum
{
VM_BLOCK_COPY = 0,
} ESysCallType;
static ELastCommand LastCommand;
static void ErrJump( void )
{
Com_Error(ERR_DROP, "program tried to execute code outside VM");
exit(1);
}
static void (*const errJumpPtr)(void) = ErrJump;
static inline int iss8(int32_t v)
{
return (v >= -0x80 && v <= 0x7f);
}
static inline int isu8(uint32_t v)
{
return (v <= 0xff);
}
static int NextConstant4(void)
{
return (code[pc] | (code[pc+1]<<8) | (code[pc+2]<<16) | (code[pc+3]<<24));
}
static int Constant4( void ) {
int v;
v = NextConstant4();
pc += 4;
return v;
}
static int Constant1( void ) {
int v;
v = code[pc];
pc += 1;
return v;
}
static void Emit1( int v )
{
buf[ compiledOfs ] = v;
compiledOfs++;
LastCommand = LAST_COMMAND_NONE;
}
static void Emit2(int v)
{
Emit1(v & 255);
Emit1((v >> 8) & 255);
}
static void Emit4( int v ) {
Emit1( v & 255 );
Emit1( ( v >> 8 ) & 255 );
Emit1( ( v >> 16 ) & 255 );
Emit1( ( v >> 24 ) & 255 );
}
static int Hex( int c ) {
if ( c >= 'a' && c <= 'f' ) {
return 10 + c - 'a';
}
if ( c >= 'A' && c <= 'F' ) {
return 10 + c - 'A';
}
if ( c >= '0' && c <= '9' ) {
return c - '0';
}
VMFREE_BUFFERS();
Com_Error( ERR_DROP, "Hex: bad char '%c'", c );
return 0;
}
static void EmitString( const char *string ) {
int c1, c2;
int v;
while ( 1 ) {
c1 = string[0];
c2 = string[1];
v = ( Hex( c1 ) << 4 ) | Hex( c2 );
Emit1( v );
if ( !string[2] ) {
break;
}
string += 3;
}
}
#define MASK_REG(modrm, mask) \
EmitString("81"); \
EmitString((modrm)); \
Emit4((mask))
// add bl, bytes
#define STACK_PUSH(bytes) \
EmitString("80 C3"); \
Emit1(bytes)
// sub bl, bytes
#define STACK_POP(bytes) \
EmitString("80 EB"); \
Emit1(bytes)
static void EmitCommand(ELastCommand command)
{
switch(command)
{
case LAST_COMMAND_MOV_STACK_EAX:
EmitString("89 04 9F"); // mov dword ptr [edi + ebx * 4], eax
break;
case LAST_COMMAND_SUB_BL_1:
STACK_POP(1); // sub bl, 1
break;
case LAST_COMMAND_SUB_BL_2:
STACK_POP(2); // sub bl, 2
break;
default:
break;
}
LastCommand = command;
}
static void EmitPushStack(vm_t *vm)
{
if (!jlabel)
{
if(LastCommand == LAST_COMMAND_SUB_BL_1)
{ // sub bl, 1
compiledOfs -= 3;
vm->instructionPointers[instruction - 1] = compiledOfs;
return;
}
if(LastCommand == LAST_COMMAND_SUB_BL_2)
{ // sub bl, 2
compiledOfs -= 3;
vm->instructionPointers[instruction - 1] = compiledOfs;
STACK_POP(1); // sub bl, 1
return;
}
}
STACK_PUSH(1); // add bl, 1
}
static void EmitMovEAXStack(vm_t *vm, int andit)
{
if(!jlabel)
{
if(LastCommand == LAST_COMMAND_MOV_STACK_EAX)
{ // mov [edi + ebx * 4], eax
compiledOfs -= 3;
vm->instructionPointers[instruction - 1] = compiledOfs;
}
else if(pop1 == OP_CONST && buf[compiledOfs-7] == 0xC7 && buf[compiledOfs-6] == 0x04 && buf[compiledOfs - 5] == 0x9F)
{ // mov [edi + ebx * 4], 0x12345678
compiledOfs -= 7;
vm->instructionPointers[instruction - 1] = compiledOfs;
EmitString("B8"); // mov eax, 0x12345678
if(andit)
Emit4(lastConst & andit);
else
Emit4(lastConst);
return;
}
else if(pop1 != OP_DIVI && pop1 != OP_DIVU && pop1 != OP_MULI && pop1 != OP_MULU &&
pop1 != OP_STORE4 && pop1 != OP_STORE2 && pop1 != OP_STORE1)
{
EmitString("8B 04 9F"); // mov eax, dword ptr [edi + ebx * 4]
}
}
else
EmitString("8B 04 9F"); // mov eax, dword ptr [edi + ebx * 4]
if(andit)
{
EmitString("25"); // and eax, 0x12345678
Emit4(andit);
}
}
void EmitMovECXStack(vm_t *vm)
{
if(!jlabel)
{
if(LastCommand == LAST_COMMAND_MOV_STACK_EAX) // mov [edi + ebx * 4], eax
{
compiledOfs -= 3;
vm->instructionPointers[instruction - 1] = compiledOfs;
EmitString("89 C1"); // mov ecx, eax
return;
}
if(pop1 == OP_DIVI || pop1 == OP_DIVU || pop1 == OP_MULI || pop1 == OP_MULU ||
pop1 == OP_STORE4 || pop1 == OP_STORE2 || pop1 == OP_STORE1)
{
EmitString("89 C1"); // mov ecx, eax
return;
}
}
EmitString("8B 0C 9F"); // mov ecx, dword ptr [edi + ebx * 4]
}
void EmitMovEDXStack(vm_t *vm, int andit)
{
if(!jlabel)
{
if(LastCommand == LAST_COMMAND_MOV_STACK_EAX)
{ // mov dword ptr [edi + ebx * 4], eax
compiledOfs -= 3;
vm->instructionPointers[instruction - 1] = compiledOfs;
EmitString("8B D0"); // mov edx, eax
}
else if(pop1 == OP_DIVI || pop1 == OP_DIVU || pop1 == OP_MULI || pop1 == OP_MULU ||
pop1 == OP_STORE4 || pop1 == OP_STORE2 || pop1 == OP_STORE1)
{
EmitString("8B D0"); // mov edx, eax
}
else if(pop1 == OP_CONST && buf[compiledOfs-7] == 0xC7 && buf[compiledOfs-6] == 0x07 && buf[compiledOfs - 5] == 0x9F)
{ // mov dword ptr [edi + ebx * 4], 0x12345678
compiledOfs -= 7;
vm->instructionPointers[instruction - 1] = compiledOfs;
EmitString("BA"); // mov edx, 0x12345678
if(andit)
Emit4(lastConst & andit);
else
Emit4(lastConst);
return;
}
else
EmitString("8B 14 9F"); // mov edx, dword ptr [edi + ebx * 4]
}
else
EmitString("8B 14 9F"); // mov edx, dword ptr [edi + ebx * 4]
if(andit)
MASK_REG("E2", andit); // and edx, 0x12345678
}
#define JUSED(x) \
do { \
if (x < 0 || x >= vm->instructionCount) { \
VMFREE_BUFFERS(); \
Com_Error( ERR_DROP, \
"VM_CompileX86: jump target out of range at offset %d", pc ); \
} \
jused[x] = 1; \
} while(0)
#define SET_JMPOFS(x) do { buf[(x)] = compiledOfs - ((x) + 1); } while(0)
/*
=================
DoBlockCopy
Executes OP_BLOCK_COPY
=================
*/
void DoBlockCopy(unsigned int dest, unsigned int src, size_t n)
{
unsigned int dataMask = currentVM->dataMask;
if ((dest & dataMask) != dest
|| (src & dataMask) != src
|| ((dest + n) & dataMask) != dest + n
|| ((src + n) & dataMask) != src + n)
{
Com_Error(ERR_DROP, "OP_BLOCK_COPY out of range!");
}
memcpy(currentVM->dataBase + dest, currentVM->dataBase + src, n);
}
/*
=================
DoSyscall
Uses asm to retrieve arguments from registers to work around different calling conventions
=================
*/
static void DoSyscall(void)
{
vm_t *savedVM;
int *data;
intptr_t syscallNum;
intptr_t programStack;
intptr_t *opStackBase;
intptr_t opStackOfs;
intptr_t arg;
#ifdef _MSC_VER
__asm
{
mov dword ptr syscallNum, eax
mov dword ptr programStack, esi
mov dword ptr opStackBase, edi
mov dword ptr opStackOfs, ebx
mov dword ptr arg, ecx
}
#else
__asm__ volatile(
""
: "=a" (syscallNum), "=S" (programStack), "=D" (opStackBase), "=b" (opStackOfs),
"=c" (arg)
:
: "memory"
);
#endif
if(syscallNum < 0)
{
// save currentVM so as to allow for recursive VM entry
savedVM = currentVM;
data = (int *) (savedVM->dataBase + programStack + 4);
// modify VM stack pointer for recursive VM entry
savedVM->programStack = programStack - 4;
*data = ~syscallNum;
opStackBase[opStackOfs + 1] = savedVM->systemCall(data);
currentVM = savedVM;
}
else
{
switch(syscallNum)
{
case VM_BLOCK_COPY:
if(opStackOfs < 1)
Com_Error(ERR_DROP, "VM_BLOCK_COPY failed due to corrupted opStack");
DoBlockCopy(opStackBase[opStackOfs - 1], opStackBase[opStackOfs], arg);
break;
default:
Com_Error(ERR_DROP, "Unknown VM operation %d", syscallNum);
break;
}
}
}
/*
=================
EmitCallDoSyscall
Call to DoSyscall()
=================
*/
int EmitCallDoSyscall(vm_t *vm)
{
// use edx register to store DoSyscall address
EmitString("BA"); // mov edx, DoSyscall
Emit4((intptr_t) DoSyscall);
// align the stack pointer to a 16-byte-boundary
EmitString("55"); // push ebp
EmitString("89 E5"); // mov ebp, esp
EmitString("83 E4 F0"); // and esp, 0xFFFFFFF0
// call the syscall wrapper function
EmitString("FF D2"); // call edx
// reset the stack pointer to its previous value
EmitString("89 EC"); // mov esp, ebp
EmitString("5D"); // pop ebp
EmitString("C3"); // ret
return compiledOfs;
}
/*
=================
EmitCallRel
Relative call to vm->codeBase + callOfs
=================
*/
void EmitCallRel(vm_t *vm, int callOfs)
{
EmitString("E8"); // call 0x12345678
Emit4(callOfs - compiledOfs - 4);
}
/*
=================
EmitCallProcedure
VM OP_CALL procedure for call destinations obtained at runtime
=================
*/
int EmitCallProcedure(vm_t *vm, int sysCallOfs)
{
int jmpSystemCall, jmpBadAddr;
int retval;
EmitString("8B 04 9F"); // mov eax, dword ptr [edi + ebx * 4]
STACK_POP(1); // sub bl, 1
EmitString("85 C0"); // test eax, eax
// Jump to syscall code
EmitString("7C"); // jl systemCall
jmpSystemCall = compiledOfs++;
/************ Call inside VM ************/
EmitString("81 F8"); // cmp eax, vm->instructionCount
Emit4(vm->instructionCount);
// Error jump if invalid jump target
EmitString("73"); // jae badAddr
jmpBadAddr = compiledOfs++;
EmitString("FF 14 85"); // call dword ptr [vm->instructionPointers + eax * 4]
Emit4((intptr_t) vm->instructionPointers);
EmitString("8B 04 9F"); // mov eax, dword ptr [edi + ebx * 4]
EmitString("C3"); // ret
// badAddr:
SET_JMPOFS(jmpBadAddr);
EmitString("B8"); // mov eax, ErrJump
Emit4((intptr_t) ErrJump);
EmitString("FF D0"); // call eax
/************ System Call ************/
// systemCall:
SET_JMPOFS(jmpSystemCall);
retval = compiledOfs;
EmitCallRel(vm, sysCallOfs);
// have opStack reg point at return value
STACK_PUSH(1); // add bl, 1
EmitString("C3"); // ret
return retval;
}
/*
=================
EmitJumpIns
Jump to constant instruction number
=================
*/
void EmitJumpIns(vm_t *vm, const char *jmpop, int cdest)
{
JUSED(cdest);
EmitString(jmpop); // j??? 0x12345678
// we only know all the jump addresses in the third pass
if(pass == 2)
Emit4(vm->instructionPointers[cdest] - compiledOfs - 4);
else
compiledOfs += 4;
}
/*
=================
EmitCallIns
Call to constant instruction number
=================
*/
void EmitCallIns(vm_t *vm, int cdest)
{
JUSED(cdest);
EmitString("E8"); // call 0x12345678
// we only know all the jump addresses in the third pass
if(pass)
Emit4(vm->instructionPointers[cdest] - compiledOfs - 4);
else
compiledOfs += 4;
}
/*
=================
EmitCallConst
Call to constant instruction number or syscall
=================
*/
void EmitCallConst(vm_t *vm, int cdest, int callProcOfsSyscall)
{
if(cdest < 0)
{
EmitString("B8"); // mov eax, cdest
Emit4(cdest);
EmitCallRel(vm, callProcOfsSyscall);
}
else
EmitCallIns(vm, cdest);
}
/*
=================
EmitBranchConditions
Emits x86 branch condition as given in op
=================
*/
void EmitBranchConditions(vm_t *vm, int op)
{
switch(op)
{
case OP_EQ:
EmitJumpIns(vm, "0F 84", Constant4()); // je 0x12345678
break;
case OP_NE:
EmitJumpIns(vm, "0F 85", Constant4()); // jne 0x12345678
break;
case OP_LTI:
EmitJumpIns(vm, "0F 8C", Constant4()); // jl 0x12345678
break;
case OP_LEI:
EmitJumpIns(vm, "0F 8E", Constant4()); // jle 0x12345678
break;
case OP_GTI:
EmitJumpIns(vm, "0F 8F", Constant4()); // jg 0x12345678
break;
case OP_GEI:
EmitJumpIns(vm, "0F 8D", Constant4()); // jge 0x12345678
break;
case OP_LTU:
EmitJumpIns(vm, "0F 82", Constant4()); // jb 0x12345678
break;
case OP_LEU:
EmitJumpIns(vm, "0F 86", Constant4()); // jbe 0x12345678
break;
case OP_GTU:
EmitJumpIns(vm, "0F 87", Constant4()); // ja 0x12345678
break;
case OP_GEU:
EmitJumpIns(vm, "0F 83", Constant4()); // jae 0x12345678
break;
}
}
/*
=================
ConstOptimize
Constant values for immediately following instructions may be translated to immediate values
instead of opStack operations, which will save expensive operations on memory
=================
*/
qboolean ConstOptimize(vm_t *vm, int callProcOfsSyscall)
{
int v;
int op1;
// we can safely perform optimizations only in case if
// we are 100% sure that next instruction is not a jump label
if (vm->jumpTableTargets && !jused[instruction])
op1 = code[pc+4];
else
return qfalse;
switch ( op1 ) {
case OP_LOAD4:
EmitPushStack(vm);
EmitString("B8"); // mov eax, 0x12345678
Emit4((Constant4() & vm->dataMask) + (intptr_t) vm->dataBase);
EmitString("8B 00"); // mov eax, dword ptr [eax]
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
pc++; // OP_LOAD4
instruction += 1;
return qtrue;
case OP_LOAD2:
EmitPushStack(vm);
EmitString("B8"); // mov eax, 0x12345678
Emit4((Constant4() & vm->dataMask) + (intptr_t) vm->dataBase);
EmitString("0F B7 00"); // movzx eax, word ptr [eax]
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
pc++; // OP_LOAD2
instruction += 1;
return qtrue;
case OP_LOAD1:
EmitPushStack(vm);
EmitString("B8"); // mov eax, 0x12345678
Emit4((Constant4() & vm->dataMask) + (intptr_t) vm->dataBase);
EmitString("0F B6 00"); // movzx eax, byte ptr [eax]
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
pc++; // OP_LOAD1
instruction += 1;
return qtrue;
case OP_STORE4:
EmitMovEAXStack(vm, (vm->dataMask & ~3));
EmitString("C7 80"); // mov dword ptr [eax + 0x12345678], 0x12345678
Emit4((intptr_t) vm->dataBase);
Emit4(Constant4());
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
pc++; // OP_STORE4
instruction += 1;
return qtrue;
case OP_STORE2:
EmitMovEAXStack(vm, (vm->dataMask & ~1));
EmitString("66 C7 80"); // mov word ptr [eax + 0x12345678], 0x1234
Emit4((intptr_t) vm->dataBase);
Emit2(Constant4());
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
pc++; // OP_STORE2
instruction += 1;
return qtrue;
case OP_STORE1:
EmitMovEAXStack(vm, vm->dataMask);
EmitString("C6 80"); // mov byte ptr [eax + 0x12345678], 0x12
Emit4((intptr_t) vm->dataBase);
Emit1(Constant4());
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
pc++; // OP_STORE4
instruction += 1;
return qtrue;
case OP_ADD:
v = Constant4();
EmitMovEAXStack(vm, 0);
if(iss8(v))
{
EmitString("83 C0"); // add eax, 0x7F
Emit1(v);
}
else
{
EmitString("05"); // add eax, 0x12345678
Emit4(v);
}
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
pc++; // OP_ADD
instruction += 1;
return qtrue;
case OP_SUB:
v = Constant4();
EmitMovEAXStack(vm, 0);
if(iss8(v))
{
EmitString("83 E8"); // sub eax, 0x7F
Emit1(v);
}
else
{
EmitString("2D"); // sub eax, 0x12345678
Emit4(v);
}
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
pc++; // OP_SUB
instruction += 1;
return qtrue;
case OP_MULI:
v = Constant4();
EmitMovEAXStack(vm, 0);
if(iss8(v))
{
EmitString("6B C0"); // imul eax, 0x7F
Emit1(v);
}
else
{
EmitString("69 C0"); // imul eax, 0x12345678
Emit4(v);
}
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
pc++; // OP_MULI
instruction += 1;
return qtrue;
case OP_LSH:
v = NextConstant4();
if(v < 0 || v > 31)
break;
EmitMovEAXStack(vm, 0);
EmitString("C1 E0"); // shl eax, 0x12
Emit1(v);
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
pc += 5; // CONST + OP_LSH
instruction += 1;
return qtrue;
case OP_RSHI:
v = NextConstant4();
if(v < 0 || v > 31)
break;
EmitMovEAXStack(vm, 0);
EmitString("C1 F8"); // sar eax, 0x12
Emit1(v);
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
pc += 5; // CONST + OP_RSHI
instruction += 1;
return qtrue;
case OP_RSHU:
v = NextConstant4();
if(v < 0 || v > 31)
break;
EmitMovEAXStack(vm, 0);
EmitString("C1 E8"); // shr eax, 0x12
Emit1(v);
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
pc += 5; // CONST + OP_RSHU
instruction += 1;
return qtrue;
case OP_BAND:
v = Constant4();
EmitMovEAXStack(vm, 0);
if(iss8(v))
{
EmitString("83 E0"); // and eax, 0x7F
Emit1(v);
}
else
{
EmitString("25"); // and eax, 0x12345678
Emit4(v);
}
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
pc += 1; // OP_BAND
instruction += 1;
return qtrue;
case OP_BOR:
v = Constant4();
EmitMovEAXStack(vm, 0);
if(iss8(v))
{
EmitString("83 C8"); // or eax, 0x7F
Emit1(v);
}
else
{
EmitString("0D"); // or eax, 0x12345678
Emit4(v);
}
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
pc += 1; // OP_BOR
instruction += 1;
return qtrue;
case OP_BXOR:
v = Constant4();
EmitMovEAXStack(vm, 0);
if(iss8(v))
{
EmitString("83 F0"); // xor eax, 0x7F
Emit1(v);
}
else
{
EmitString("35"); // xor eax, 0x12345678
Emit4(v);
}
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
pc += 1; // OP_BXOR
instruction += 1;
return qtrue;
case OP_EQ:
case OP_NE:
case OP_LTI:
case OP_LEI:
case OP_GTI:
case OP_GEI:
case OP_LTU:
case OP_LEU:
case OP_GTU:
case OP_GEU:
EmitMovEAXStack(vm, 0);
EmitCommand(LAST_COMMAND_SUB_BL_1);
EmitString("3D"); // cmp eax, 0x12345678
Emit4(Constant4());
pc++; // OP_*
EmitBranchConditions(vm, op1);
instruction++;
return qtrue;
case OP_EQF:
case OP_NEF:
if(NextConstant4())
break;
pc += 5; // CONST + OP_EQF|OP_NEF
EmitMovEAXStack(vm, 0);
EmitCommand(LAST_COMMAND_SUB_BL_1);
// floating point hack :)
EmitString("25"); // and eax, 0x7FFFFFFF
Emit4(0x7FFFFFFF);
if(op1 == OP_EQF)
EmitJumpIns(vm, "0F 84", Constant4()); // jz 0x12345678
else
EmitJumpIns(vm, "0F 85", Constant4()); // jnz 0x12345678
instruction += 1;
return qtrue;
case OP_JUMP:
EmitJumpIns(vm, "E9", Constant4()); // jmp 0x12345678
pc += 1; // OP_JUMP
instruction += 1;
return qtrue;
case OP_CALL:
v = Constant4();
EmitCallConst(vm, v, callProcOfsSyscall);
pc += 1; // OP_CALL
instruction += 1;
return qtrue;
default:
break;
}
return qfalse;
}
/*
=================
VM_Compile
=================
*/
void VM_Compile(vm_t *vm, vmHeader_t *header)
{
int op;
int maxLength;
int v;
int i;
int callProcOfsSyscall, callProcOfs;
jusedSize = header->instructionCount + 2;
// allocate a very large temp buffer, we will shrink it later
maxLength = header->codeLength * 8 + 64;
buf = Z_Malloc(maxLength);
jused = Z_Malloc(jusedSize);
code = Z_Malloc(header->codeLength+32);
Com_Memset(jused, 0, jusedSize);
Com_Memset(buf, 0, maxLength);
// copy code in larger buffer and put some zeros at the end
// so we can safely look ahead for a few instructions in it
// without a chance to get false-positive because of some garbage bytes
Com_Memset(code, 0, header->codeLength+32);
Com_Memcpy(code, (byte *)header + header->codeOffset, header->codeLength );
// ensure that the optimisation pass knows about all the jump
// table targets
for( i = 0; i < vm->numJumpTableTargets; i++ ) {
jused[ *(int *)(vm->jumpTableTargets + ( i * sizeof( int ) ) ) ] = 1;
}
// Start buffer with x86-VM specific procedures
compiledOfs = 0;
callProcOfs = EmitCallDoSyscall(vm);
callProcOfsSyscall = EmitCallProcedure(vm, 0);
vm->entryOfs = compiledOfs;
for(pass=0; pass < 3; pass++) {
oc0 = -23423;
oc1 = -234354;
pop0 = -43435;
pop1 = -545455;
// translate all instructions
pc = 0;
instruction = 0;
//code = (byte *)header + header->codeOffset;
compiledOfs = vm->entryOfs;
LastCommand = LAST_COMMAND_NONE;
while(instruction < header->instructionCount)
{
if(compiledOfs > maxLength - 16)
{
VMFREE_BUFFERS();
Com_Error(ERR_DROP, "VM_CompileX86: maxLength exceeded");
}
vm->instructionPointers[ instruction ] = compiledOfs;
if ( !vm->jumpTableTargets )
jlabel = 1;
else
jlabel = jused[ instruction ];
instruction++;
if(pc > header->codeLength)
{
VMFREE_BUFFERS();
Com_Error(ERR_DROP, "VM_CompileX86: pc > header->codeLength");
}
op = code[ pc ];
pc++;
switch ( op ) {
case 0:
break;
case OP_BREAK:
EmitString("CC"); // int 3
break;
case OP_ENTER:
EmitString("81 EE"); // sub esi, 0x12345678
Emit4(Constant4());
break;
case OP_CONST:
if(ConstOptimize(vm, callProcOfsSyscall))
break;
EmitPushStack(vm);
EmitString("C7 04 9F"); // mov dword ptr [edi + ebx * 4], 0x12345678
lastConst = Constant4();
Emit4(lastConst);
if(code[pc] == OP_JUMP)
JUSED(lastConst);
break;
case OP_LOCAL:
EmitPushStack(vm);
EmitString("8D 86"); // lea eax, [0x12345678 + esi]
oc0 = oc1;
oc1 = Constant4();
Emit4(oc1);
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
break;
case OP_ARG:
EmitMovEAXStack(vm, 0); // mov eax, dword ptr [edi + ebx * 4]
EmitString("8B D6"); // mov edx, esi
EmitString("81 C2"); // add edx, 0x12345678
Emit4((Constant1() & 0xFF));
MASK_REG("E2", vm->dataMask); // and edx, 0x12345678
EmitString("89 82"); // mov dword ptr [edx + 0x12345678], eax
Emit4((intptr_t) vm->dataBase);
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_CALL:
EmitCallRel(vm, callProcOfs);
break;
case OP_PUSH:
EmitPushStack(vm);
break;
case OP_POP:
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_LEAVE:
v = Constant4();
EmitString("81 C6"); // add esi, 0x12345678
Emit4(v);
EmitString("C3"); // ret
break;
case OP_LOAD4:
if (code[pc] == OP_CONST && code[pc+5] == OP_ADD && code[pc+6] == OP_STORE4)
{
if(oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL)
{
compiledOfs -= 12;
vm->instructionPointers[instruction - 1] = compiledOfs;
}
pc++; // OP_CONST
v = Constant4();
EmitMovEDXStack(vm, vm->dataMask);
if(v == 1 && oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL)
{
EmitString("FF 82"); // inc dword ptr [edx + 0x12345678]
Emit4((intptr_t) vm->dataBase);
}
else
{
EmitString("8B 82"); // mov eax, dword ptr [edx + 0x12345678]
Emit4((intptr_t) vm->dataBase);
EmitString("05"); // add eax, const
Emit4(v);
if (oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL)
{
EmitString("89 82"); // mov dword ptr [edx + 0x12345678], eax
Emit4((intptr_t) vm->dataBase);
}
else
{
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
EmitString("8B 14 9F"); // mov edx, dword ptr [edi + ebx * 4]
MASK_REG("E2", vm->dataMask); // and edx, 0x12345678
EmitString("89 82"); // mov dword ptr [edx + 0x12345678], eax
Emit4((intptr_t) vm->dataBase);
}
}
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
pc++; // OP_ADD
pc++; // OP_STORE
instruction += 3;
break;
}
if(code[pc] == OP_CONST && code[pc+5] == OP_SUB && code[pc+6] == OP_STORE4)
{
if(oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL)
{
compiledOfs -= 12;
vm->instructionPointers[instruction - 1] = compiledOfs;
}
pc++; // OP_CONST
v = Constant4();
EmitMovEDXStack(vm, vm->dataMask);
if(v == 1 && oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL)
{
EmitString("FF 8A"); // dec dword ptr [edx + 0x12345678]
Emit4((intptr_t) vm->dataBase);
}
else
{
EmitString("8B 82"); // mov eax, dword ptr [edx + 0x12345678]
Emit4((intptr_t) vm->dataBase);
EmitString("2D"); // sub eax, const
Emit4(v);
if(oc0 == oc1 && pop0 == OP_LOCAL && pop1 == OP_LOCAL)
{
EmitString("89 82"); // mov dword ptr [edx + 0x12345678], eax
Emit4((intptr_t) vm->dataBase);
}
else
{
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
EmitString("8B 14 9F"); // mov edx, dword ptr [edi + ebx * 4]
MASK_REG("E2", vm->dataMask); // and edx, 0x12345678
EmitString("89 82"); // mov dword ptr [edx + 0x12345678], eax
Emit4((intptr_t) vm->dataBase);
}
}
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
pc++; // OP_SUB
pc++; // OP_STORE
instruction += 3;
break;
}
if(buf[compiledOfs - 3] == 0x89 && buf[compiledOfs - 2] == 0x04 && buf[compiledOfs - 1] == 0x9F)
{
compiledOfs -= 3;
vm->instructionPointers[instruction - 1] = compiledOfs;
MASK_REG("E0", vm->dataMask); // and eax, 0x12345678
EmitString("8B 80"); // mov eax, dword ptr [eax + 0x1234567]
Emit4((intptr_t) vm->dataBase);
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
break;
}
EmitMovEAXStack(vm, vm->dataMask);
EmitString("8B 80"); // mov eax, dword ptr [eax + 0x12345678]
Emit4((intptr_t) vm->dataBase);
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
break;
case OP_LOAD2:
EmitMovEAXStack(vm, vm->dataMask);
EmitString("0F B7 80"); // movzx eax, word ptr [eax + 0x12345678]
Emit4((intptr_t) vm->dataBase);
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
break;
case OP_LOAD1:
EmitMovEAXStack(vm, vm->dataMask);
EmitString("0F B6 80"); // movzx eax, byte ptr [eax + 0x12345678]
Emit4((intptr_t) vm->dataBase);
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
break;
case OP_STORE4:
EmitMovEAXStack(vm, 0);
EmitString("8B 54 9F FC"); // mov edx, dword ptr -4[edi + ebx * 4]
MASK_REG("E2", vm->dataMask & ~3); // and edx, 0x12345678
EmitString("89 82"); // mov dword ptr [edx + 0x12345678], eax
Emit4((intptr_t) vm->dataBase);
EmitCommand(LAST_COMMAND_SUB_BL_2); // sub bl, 2
break;
case OP_STORE2:
EmitMovEAXStack(vm, 0);
EmitString("8B 54 9F FC"); // mov edx, dword ptr -4[edi + ebx * 4]
MASK_REG("E2", vm->dataMask & ~1); // and edx, 0x12345678
EmitString("66 89 82"); // mov word ptr [edx + 0x12345678], eax
Emit4((intptr_t) vm->dataBase);
EmitCommand(LAST_COMMAND_SUB_BL_2); // sub bl, 2
break;
case OP_STORE1:
EmitMovEAXStack(vm, 0);
EmitString("8B 54 9F FC"); // mov edx, dword ptr -4[edi + ebx * 4]
MASK_REG("E2", vm->dataMask); // and edx, 0x12345678
EmitString("88 82"); // mov byte ptr [edx + 0x12345678], eax
Emit4((intptr_t) vm->dataBase);
EmitCommand(LAST_COMMAND_SUB_BL_2); // sub bl, 2
break;
case OP_EQ:
case OP_NE:
case OP_LTI:
case OP_LEI:
case OP_GTI:
case OP_GEI:
case OP_LTU:
case OP_LEU:
case OP_GTU:
case OP_GEU:
EmitMovEAXStack(vm, 0);
EmitCommand(LAST_COMMAND_SUB_BL_2); // sub bl, 2
EmitString("39 44 9F 04"); // cmp eax, dword ptr 4[edi + ebx * 4]
EmitBranchConditions(vm, op);
break;
case OP_EQF:
case OP_NEF:
case OP_LTF:
case OP_LEF:
case OP_GTF:
case OP_GEF:
EmitCommand(LAST_COMMAND_SUB_BL_2); // sub bl, 2
EmitString("D9 44 9F 04"); // fld dword ptr 4[edi + ebx * 4]
EmitString("D8 5C 9F 08"); // fcomp dword ptr 8[edi + ebx * 4]
EmitString("DF E0"); // fnstsw ax
switch(op)
{
case OP_EQF:
EmitString("F6 C4 40"); // test ah,0x40
EmitJumpIns(vm, "0F 85", Constant4()); // jne 0x12345678
break;
case OP_NEF:
EmitString("F6 C4 40"); // test ah,0x40
EmitJumpIns(vm, "0F 84", Constant4()); // je 0x12345678
break;
case OP_LTF:
EmitString("F6 C4 01"); // test ah,0x01
EmitJumpIns(vm, "0F 85", Constant4()); // jne 0x12345678
break;
case OP_LEF:
EmitString("F6 C4 41"); // test ah,0x41
EmitJumpIns(vm, "0F 85", Constant4()); // jne 0x12345678
break;
case OP_GTF:
EmitString("F6 C4 41"); // test ah,0x41
EmitJumpIns(vm, "0F 84", Constant4()); // je 0x12345678
break;
case OP_GEF:
EmitString("F6 C4 01"); // test ah,0x01
EmitJumpIns(vm, "0F 84", Constant4()); // je 0x12345678
break;
}
break;
case OP_NEGI:
EmitMovEAXStack(vm, 0);
EmitString("F7 D8"); // neg eax
EmitCommand(LAST_COMMAND_MOV_STACK_EAX);
break;
case OP_ADD:
EmitMovEAXStack(vm, 0); // mov eax, dword ptr [edi + ebx * 4]
EmitString("01 44 9F FC"); // add dword ptr -4[edi + ebx * 4], eax
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_SUB:
EmitMovEAXStack(vm, 0); // mov eax, dword ptr [edi + ebx * 4]
EmitString("29 44 9F FC"); // sub dword ptr -4[edi + ebx * 4], eax
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_DIVI:
EmitString("8B 44 9F FC"); // mov eax,dword ptr -4[edi + ebx * 4]
EmitString("99"); // cdq
EmitString("F7 3C 9F"); // idiv dword ptr [edi + ebx * 4]
EmitString("89 44 9F FC"); // mov dword ptr -4[edi + ebx * 4],eax
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_DIVU:
EmitString("8B 44 9F FC"); // mov eax,dword ptr -4[edi + ebx * 4]
EmitString("33 D2"); // xor edx, edx
EmitString("F7 34 9F"); // div dword ptr [edi + ebx * 4]
EmitString("89 44 9F FC"); // mov dword ptr -4[edi + ebx * 4],eax
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_MODI:
EmitString("8B 44 9F FC"); // mov eax,dword ptr -4[edi + ebx * 4]
EmitString("99" ); // cdq
EmitString("F7 3C 9F"); // idiv dword ptr [edi + ebx * 4]
EmitString("89 54 9F FC"); // mov dword ptr -4[edi + ebx * 4],edx
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_MODU:
EmitString("8B 44 9F FC"); // mov eax,dword ptr -4[edi + ebx * 4]
EmitString("33 D2"); // xor edx, edx
EmitString("F7 34 9F"); // div dword ptr [edi + ebx * 4]
EmitString("89 54 9F FC"); // mov dword ptr -4[edi + ebx * 4],edx
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_MULI:
EmitString("8B 44 9F FC"); // mov eax,dword ptr -4[edi + ebx * 4]
EmitString("F7 2C 9F"); // imul dword ptr [edi + ebx * 4]
EmitString("89 44 9F FC"); // mov dword ptr -4[edi + ebx * 4],eax
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_MULU:
EmitString("8B 44 9F FC"); // mov eax,dword ptr -4[edi + ebx * 4]
EmitString("F7 24 9F"); // mul dword ptr [edi + ebx * 4]
EmitString("89 44 9F FC"); // mov dword ptr -4[edi + ebx * 4],eax
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_BAND:
EmitMovEAXStack(vm, 0); // mov eax, dword ptr [edi + ebx * 4]
EmitString("21 44 9F FC"); // and dword ptr -4[edi + ebx * 4],eax
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_BOR:
EmitMovEAXStack(vm, 0); // mov eax, dword ptr [edi + ebx * 4]
EmitString("09 44 9F FC"); // or dword ptr -4[edi + ebx * 4],eax
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_BXOR:
EmitMovEAXStack(vm, 0); // mov eax, dword ptr [edi + ebx * 4]
EmitString("31 44 9F FC"); // xor dword ptr -4[edi + ebx * 4],eax
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_BCOM:
EmitString("F7 14 9F"); // not dword ptr [edi + ebx * 4]
break;
case OP_LSH:
EmitMovECXStack(vm);
EmitString("D3 64 9F FC"); // shl dword ptr -4[edi + ebx * 4], cl
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_RSHI:
EmitMovECXStack(vm);
EmitString("D3 7C 9F FC"); // sar dword ptr -4[edi + ebx * 4], cl
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_RSHU:
EmitMovECXStack(vm);
EmitString("D3 6C 9F FC"); // shr dword ptr -4[edi + ebx * 4], cl
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_NEGF:
EmitString("D9 04 9F"); // fld dword ptr [edi + ebx * 4]
EmitString("D9 E0"); // fchs
EmitString("D9 1C 9F"); // fstp dword ptr [edi + ebx * 4]
break;
case OP_ADDF:
EmitString("D9 44 9F FC"); // fld dword ptr -4[edi + ebx * 4]
EmitString("D8 04 9F"); // fadd dword ptr [edi + ebx * 4]
EmitString("D9 5C 9F FC"); // fstp dword ptr -4[edi + ebx * 4]
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
break;
case OP_SUBF:
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
EmitString("D9 04 9F"); // fld dword ptr [edi + ebx * 4]
EmitString("D8 64 9F 04"); // fsub dword ptr 4[edi + ebx * 4]
EmitString("D9 1C 9F"); // fstp dword ptr [edi + ebx * 4]
break;
case OP_DIVF:
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
EmitString("D9 04 9F"); // fld dword ptr [edi + ebx * 4]
EmitString("D8 74 9F 04"); // fdiv dword ptr 4[edi + ebx * 4]
EmitString("D9 1C 9F"); // fstp dword ptr [edi + ebx * 4]
break;
case OP_MULF:
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
EmitString("D9 04 9F"); // fld dword ptr [edi + ebx * 4]
EmitString("D8 4C 9F 04"); // fmul dword ptr 4[edi + ebx * 4]
EmitString("D9 1C 9F"); // fstp dword ptr [edi + ebx * 4]
break;
case OP_CVIF:
EmitString("DB 04 9F"); // fild dword ptr [edi + ebx * 4]
EmitString("D9 1C 9F"); // fstp dword ptr [edi + ebx * 4]
break;
case OP_CVFI:
#ifndef FTOL_PTR // WHENHELLISFROZENOVER
// not IEEE complient, but simple and fast
EmitString("D9 04 9F"); // fld dword ptr [edi + ebx * 4]
EmitString("DB 1C 9F"); // fistp dword ptr [edi + ebx * 4]
#else // FTOL_PTR
// call the library conversion function
EmitString("D9 04 9F"); // fld dword ptr [edi + ebx * 4]
EmitString("FF 15"); // call ftolPtr
Emit4( (int)&ftolPtr );
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
#endif
break;
case OP_SEX8:
EmitString("0F BE 04 9F"); // movsx eax, byte ptr [edi + ebx * 4]
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
break;
case OP_SEX16:
EmitString("0F BF 04 9F"); // movsx eax, word ptr [edi + ebx * 4]
EmitCommand(LAST_COMMAND_MOV_STACK_EAX); // mov dword ptr [edi + ebx * 4], eax
break;
case OP_BLOCK_COPY:
EmitString("B8"); // mov eax, 0x12345678
Emit4(VM_BLOCK_COPY);
EmitString("B9"); // mov ecx, 0x12345678
Emit4(Constant4());
EmitCallRel(vm, 0);
EmitCommand(LAST_COMMAND_SUB_BL_2); // sub bl, 2
break;
case OP_JUMP:
EmitCommand(LAST_COMMAND_SUB_BL_1); // sub bl, 1
EmitString("8B 44 9F 04"); // mov eax,dword ptr 4[edi + ebx * 4]
EmitString("81 F8"); // cmp eax, vm->instructionCount
Emit4(vm->instructionCount);
EmitString("73 07"); // jae +7
EmitString("FF 24 85"); // jmp dword ptr [instructionPointers + eax * 4]
Emit4((intptr_t) vm->instructionPointers);
EmitString("FF 15"); // call errJumpPtr
Emit4((intptr_t) &errJumpPtr);
break;
default:
VMFREE_BUFFERS();
Com_Error(ERR_DROP, "VM_CompileX86: bad opcode %i at offset %i", op, pc);
}
pop0 = pop1;
pop1 = op;
}
}
// copy to an exact sized buffer with the appropriate permission bits
vm->codeLength = compiledOfs;
#ifdef VM_X86_MMAP
vm->codeBase = mmap(NULL, compiledOfs, PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
if(vm->codeBase == MAP_FAILED)
Com_Error(ERR_FATAL, "VM_CompileX86: can't mmap memory");
#elif _WIN32
// allocate memory with EXECUTE permissions under windows.
vm->codeBase = VirtualAlloc(NULL, compiledOfs, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
if(!vm->codeBase)
Com_Error(ERR_FATAL, "VM_CompileX86: VirtualAlloc failed");
#else
vm->codeBase = malloc(compiledOfs);
if(!vm->codeBase)
Com_Error(ERR_FATAL, "VM_CompileX86: malloc failed");
#endif
Com_Memcpy( vm->codeBase, buf, compiledOfs );
#ifdef VM_X86_MMAP
if(mprotect(vm->codeBase, compiledOfs, PROT_READ|PROT_EXEC))
Com_Error(ERR_FATAL, "VM_CompileX86: mprotect failed");
#elif _WIN32
{
DWORD oldProtect = 0;
// remove write permissions.
if(!VirtualProtect(vm->codeBase, compiledOfs, PAGE_EXECUTE_READ, &oldProtect))
Com_Error(ERR_FATAL, "VM_CompileX86: VirtualProtect failed");
}
#endif
Z_Free( code );
Z_Free( buf );
Z_Free( jused );
Com_Printf( "VM file %s compiled to %i bytes of code\n", vm->name, compiledOfs );
vm->destroy = VM_Destroy_Compiled;
// offset all the instruction pointers for the new location
for ( i = 0 ; i < header->instructionCount ; i++ ) {
vm->instructionPointers[i] += (int)vm->codeBase;
}
}
void VM_Destroy_Compiled(vm_t* self)
{
#ifdef VM_X86_MMAP
munmap(self->codeBase, self->codeLength);
#elif _WIN32
VirtualFree(self->codeBase, 0, MEM_RELEASE);
#else
free(self->codeBase);
#endif
}
/*
==============
VM_CallCompiled
This function is called directly by the generated code
==============
*/
int VM_CallCompiled(vm_t *vm, int *args)
{
int stack[OPSTACK_SIZE + 3];
void *entryPoint;
int programCounter;
int programStack, stackOnEntry;
byte *image;
int *opStack, *opStackOnEntry;
int opStackOfs;
currentVM = vm;
// interpret the code
vm->currentlyInterpreting = qtrue;
// we might be called recursively, so this might not be the very top
programStack = stackOnEntry = vm->programStack;
// set up the stack frame
image = vm->dataBase;
programCounter = 0;
programStack -= 48;
*(int *)&image[ programStack + 44] = args[9];
*(int *)&image[ programStack + 40] = args[8];
*(int *)&image[ programStack + 36] = args[7];
*(int *)&image[ programStack + 32] = args[6];
*(int *)&image[ programStack + 28] = args[5];
*(int *)&image[ programStack + 24] = args[4];
*(int *)&image[ programStack + 20] = args[3];
*(int *)&image[ programStack + 16] = args[2];
*(int *)&image[ programStack + 12] = args[1];
*(int *)&image[ programStack + 8 ] = args[0];
*(int *)&image[ programStack + 4 ] = 0; // return stack
*(int *)&image[ programStack ] = -1; // will terminate the loop on return
// off we go into generated code...
entryPoint = vm->codeBase + vm->entryOfs;
opStack = opStackOnEntry = PADP(stack, 4);
*opStack = 0xDEADBEEF;
opStackOfs = 0;
#ifdef _MSC_VER
__asm
{
pushad
mov esi, programStack
mov edi, opStack
mov ebx, opStackOfs
call entryPoint
mov opStackOfs, ebx
mov opStack, edi
mov programStack, esi
popad
}
#else
__asm__ volatile(
"calll *%3\r\n"
: "+S" (programStack), "+D" (opStack), "+b" (opStackOfs)
: "g" (entryPoint)
: "cc", "memory", "%eax", "%ecx", "%edx"
);
#endif
if(opStack != opStackOnEntry || opStackOfs != 1 || *opStack != 0xDEADBEEF)
Com_Error(ERR_DROP, "opStack corrupted in compiled code");
if(programStack != stackOnEntry - 48)
Com_Error(ERR_DROP, "programStack corrupted in compiled code");
vm->programStack = stackOnEntry;
return opStack[opStackOfs];
}