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Diffstat (limited to 'src/qcommon/vm_x86.c')
-rw-r--r--src/qcommon/vm_x86.c386
1 files changed, 320 insertions, 66 deletions
diff --git a/src/qcommon/vm_x86.c b/src/qcommon/vm_x86.c
index afa29d4c..ec43b631 100644
--- a/src/qcommon/vm_x86.c
+++ b/src/qcommon/vm_x86.c
@@ -57,12 +57,11 @@ static void VM_Destroy_Compiled(vm_t* self);
#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;
-static int *instructionPointers = NULL;
-
#define FTOL_PTR
#ifdef _MSC_VER
@@ -92,8 +91,6 @@ void AsmCall(void);
static void (*const asmCallPtr)(void) = AsmCall;
-static int callMask = 0;
-
static int instruction, pass;
static int lastConst = 0;
static int oc0, oc1, pop0, pop1;
@@ -108,6 +105,14 @@ typedef enum
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;
+
/*
=================
AsmCall
@@ -125,13 +130,21 @@ __asm {
sub edi, 4
test eax,eax
jl systemCall
+ cmp eax, [currentVM->instructionCount]
+ jae badAddr
// calling another vm function
shl eax,2
- add eax, dword ptr [instructionPointers]
+ add eax, dword ptr [currentVM->instructionPointers]
call dword ptr [eax]
mov eax, dword ptr [edi]
- and eax, [callMask]
ret
+badAddr:
+ call ErrJump
+ // leave something on the opstack
+ //add edi, 4
+ //mov dword ptr [edi], 0
+ //ret
+
systemCall:
// convert negative num to system call number
@@ -202,44 +215,61 @@ static void __attribute__((cdecl, used)) CallAsmCall(int const syscallNum,
currentVM = vm;
}
-__asm__(
- ".text\n\t"
- ".p2align 4,,15\n\t"
-#if defined __ELF__
- ".type " CMANGFUNC(AsmCall) ", @function\n"
-#endif
- CMANGFUNC(AsmCall) ":\n\t"
- "movl (%edi), %eax\n\t"
- "subl $4, %edi\n\t"
- "testl %eax, %eax\n\t"
+void AsmCall(void)
+{
+__asm__ __volatile__(
+// ".text\n\t"
+// ".p2align 4,,15\n\t"
+// #if defined __ELF__
+// ".type " CMANGFUNC(AsmCall) ", @function\n"
+// #endif
+// CMANGFUNC(AsmCall) ":\n\t"
+ "movl (%%edi), %%eax\n\t"
+ "subl $4, %%edi\n\t"
+// "movl " CMANGVAR(currentVM) ", %ebx\n\t"
+ "testl %%eax, %%eax\n\t"
"jl 0f\n\t"
- "shll $2, %eax\n\t"
- "addl " CMANGVAR(instructionPointers) ", %eax\n\t"
- "call *(%eax)\n\t"
- "movl (%edi), %eax\n\t"
- "andl " CMANGVAR(callMask) ", %eax\n\t"
- "ret\n"
+ "cmpl %0, %%eax\n\t"
+// "cmpl 0x68(%ebx), %eax\n\t"
+ "jae 1f\n\t"
+ "shll $2, %%eax\n\t"
+ "addl %1, %%eax\n\t"
+// "addl 0x64(%ebx), %eax\n\t"
+ "call *(%%eax)\n\t"
+ "movl (%%edi), %%eax\n\t"
+ "jmp 2f\n\t"
+ "1:\n\t" // bad address, leave something on the opstack
+ "call " CMANGFUNC(ErrJump) "\n\t"
+ //"addl $4, %edi\n\t"
+ //"movl $0, (%edi)\n\t"
+ //"ret\n\t"
"0:\n\t" // system call
- "notl %eax\n\t"
- "pushl %ebp\n\t"
- "movl %esp, %ebp\n\t"
- "andl $-16, %esp\n\t" // align the stack so engine can use sse
- "pushl %ecx\n\t"
- "pushl %edi\n\t" // opStack
- "pushl %esi\n\t" // programStack
- "pushl %eax\n\t" // syscallNum
+ "notl %%eax\n\t"
+ "pushl %%ebp\n\t"
+ "movl %%esp, %%ebp\n\t"
+
+ "andl $-16, %%esp\n\t" // align the stack so engine can use sse
+ "addl $4, %%esp\n\t"
+ "pushl %%edi\n\t" // opStack
+ "pushl %%esi\n\t" // programStack
+ "pushl %%eax\n\t" // syscallNum
"call " CMANGFUNC(CallAsmCall) "\n\t"
- "addl $12, %esp\n\t"
- "popl %ecx\n\t"
- "movl %ebp, %esp\n\t"
- "popl %ebp\n\t"
- "addl $4, %edi\n\t"
- "ret\n\t"
+// "addl $12, %%esp\n\t"
+ "movl %%ebp, %%esp\n\t"
+ "popl %%ebp\n\t"
+ "addl $4, %%edi\n\t"
+ "2:\n\t"
+// "ret\n\t"
#if defined __ELF__
- ".size " CMANGFUNC(AsmCall)", .-" CMANGFUNC(AsmCall)
+// ".size " CMANGFUNC(AsmCall)", .-" CMANGFUNC(AsmCall)
#endif
+ :
+ : "g" (currentVM->instructionCount), "g" (currentVM->instructionPointers)
+ : "%eax"
);
+}
+
#endif
static int Constant4( void ) {
@@ -250,6 +280,11 @@ static int Constant4( void ) {
return v;
}
+static int NextConstant4( void ) {
+ return (code[pc] | (code[pc+1]<<8) | (code[pc+2]<<16) | (code[pc+3]<<24));
+}
+
+
static int Constant1( void ) {
int v;
@@ -420,23 +455,150 @@ qboolean EmitMovEBXEDI(vm_t *vm, int andit) {
/*
=================
+DoSyscall
+Uses asm to get arguments from stack to work around different calling conventions
+=================
+*/
+
+static void DoSyscall(void)
+{
+ vm_t *savedVM;
+ int *data;
+
+ int syscallNum;
+ int programStack;
+ int *opStack;
+
+ // Get arguments directly from registers to work around different calling conventions
+#ifdef _MSC_VER
+ __asm
+ {
+ mov dword ptr syscallNum, eax
+ mov dword ptr programStack, esi
+ mov dword ptr opStack, edi
+ }
+#else
+ __asm__ volatile(
+ ""
+ : "=a" (syscallNum), "=S" (programStack), "=D" (opStack)
+ :
+ : "memory"
+ );
+#endif
+
+ // save currentVM 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;
+ opStack[1] = savedVM->systemCall(data);
+
+ currentVM = savedVM;
+}
+
+/*
+=================
+EmitVMCall
+=================
+*/
+
+void EmitVMCall(void)
+{
+ EmitString("FF 25"); // jmp dword ptr [instructionPointers + 0x12345678]
+ Emit4((intptr_t) vm->instructionPointers + v*4);
+}
+
+/*
+=================
+EmitSysCall
+=================
+*/
+
+void EmitSysCall(void)
+{
+ EmitString("F7 D0"); // not eax
+
+ // use ecx register to store DoSyscall address
+ EmitString("51"); // push ecx
+ EmitString("B1"); // mov ecx, [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 D1"); // call ecx
+
+ // reset the stack pointer to its previous value
+ EmitString("89 EC"); // mov esp, ebp
+ EmitString("5D"); // pop ebp
+ EmitString("59"); // pop ecx
+
+ // have opStack reg point at return value
+ EmitString("83 C7 04"); // add edi, 4
+}
+
+/*
+=================
+EmitCall
+=================
+*/
+
+void EmitCall(qboolean got_const, int cdest)
+{
+ if(got_const)
+ {
+ EmitString("B8"); // mov eax, cdest
+ Emit4(cdest);
+
+ if(cdest < 0)
+ EmitSysCall();
+ else
+ {
+ JUSED(cdest);
+ EmitVMCall();
+ }
+ }
+ else
+ {
+// EmitString();
+ }
+
+}
+
+/*
+=================
VM_Compile
=================
*/
void VM_Compile( vm_t *vm, vmHeader_t *header ) {
int op;
+ int op1;
int maxLength;
int v;
int i;
qboolean opt;
- int jusedSize = header->instructionCount + 2;
+
+ jusedSize = header->instructionCount + 2;
// allocate a very large temp buffer, we will shrink it later
maxLength = header->codeLength * 8;
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
@@ -453,7 +615,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
// translate all instructions
pc = 0;
instruction = 0;
- code = (byte *)header + header->codeOffset;
+ //code = (byte *)header + header->codeOffset;
compiledOfs = 0;
LastCommand = LAST_COMMAND_NONE;
@@ -488,7 +650,14 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
Emit4( Constant4() );
break;
case OP_CONST:
- if (code[pc+4] == OP_LOAD4) {
+ // we can safely perform optimizations only in case if
+ // we are 100% sure that next instruction is not a jump label
+ if ( !jused[instruction] && vm->jumpTableTargets )
+ op1 = code[pc+4];
+ else
+ op1 = OP_UNDEF;
+
+ if ( op1 == OP_LOAD4 ) {
EmitAddEDI4(vm);
EmitString( "BB" ); // mov ebx, 0x12345678
Emit4( (Constant4()&vm->dataMask) + (int)vm->dataBase);
@@ -498,7 +667,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
instruction += 1;
break;
}
- if (code[pc+4] == OP_LOAD2) {
+ if ( op1 == OP_LOAD2 ) {
EmitAddEDI4(vm);
EmitString( "BB" ); // mov ebx, 0x12345678
Emit4( (Constant4()&vm->dataMask) + (int)vm->dataBase);
@@ -508,7 +677,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
instruction += 1;
break;
}
- if (code[pc+4] == OP_LOAD1) {
+ if ( op1 == OP_LOAD1 ) {
EmitAddEDI4(vm);
EmitString( "BB" ); // mov ebx, 0x12345678
Emit4( (Constant4()&vm->dataMask) + (int)vm->dataBase);
@@ -518,7 +687,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
instruction += 1;
break;
}
- if (code[pc+4] == OP_STORE4) {
+ if ( op1 == OP_STORE4 ) {
opt = EmitMovEBXEDI(vm, (vm->dataMask & ~3));
EmitString( "B8" ); // mov eax, 0x12345678
Emit4( Constant4() );
@@ -533,7 +702,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
instruction += 1;
break;
}
- if (code[pc+4] == OP_STORE2) {
+ if ( op1 == OP_STORE2 ) {
opt = EmitMovEBXEDI(vm, (vm->dataMask & ~1));
EmitString( "B8" ); // mov eax, 0x12345678
Emit4( Constant4() );
@@ -548,7 +717,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
instruction += 1;
break;
}
- if (code[pc+4] == OP_STORE1) {
+ if ( op1 == OP_STORE1 ) {
opt = EmitMovEBXEDI(vm, vm->dataMask);
EmitString( "B8" ); // mov eax, 0x12345678
Emit4( Constant4() );
@@ -563,20 +732,113 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
instruction += 1;
break;
}
- if (code[pc+4] == OP_ADD) {
+ if ( op1 == OP_ADD ) {
+ v = NextConstant4();
+ if ( v == 1 ) {
+ EmitString( "FF 07" ); // inc dword ptr [edi]
+ pc += 5; // OP_CONST + OP_ADD
+ instruction += 1;
+ break;
+ }
EmitString( "81 07" ); // add dword ptr [edi], 0x1234567
Emit4( Constant4() );
pc++; // OP_ADD
instruction += 1;
break;
}
- if (code[pc+4] == OP_SUB) {
+ if ( op1 == OP_SUB ) {
+ v = NextConstant4();
+ if ( v == 1 ) {
+ EmitString( "FF 0F" ); // dec dword ptr [edi]
+ pc += 5; // OP_CONST + OP_SUB
+ instruction += 1;
+ break;
+ }
EmitString( "81 2F" ); // sub dword ptr [edi], 0x1234567
Emit4( Constant4() );
pc++; // OP_ADD
instruction += 1;
break;
}
+ if ( op1 == OP_LSH ) {
+ v = NextConstant4();
+ if ( v >=1 && v <= 31 ) {
+ EmitString( "C1 27" ); // shl dword ptr [edi], 0x12
+ Emit1( v );
+ pc += 5; // OP_CONST + OP_LSH
+ instruction += 1;
+ break;
+ }
+ }
+ if ( op1 == OP_RSHI ) {
+ v = NextConstant4();
+ if ( v >=1 && v <= 31 ) {
+ EmitString( "C1 3F" ); // sar dword ptr [edi], 0x12
+ Emit1( v );
+ pc += 5; // OP_CONST + OP_RSHI
+ instruction += 1;
+ break;
+ }
+ }
+ if ( op1 == OP_RSHU ) {
+ v = NextConstant4();
+ if ( v >=1 && v <= 31 ) {
+ EmitString( "C1 2F" ); // shr dword ptr [edi], 0x12
+ Emit1( v );
+ pc += 5; // OP_CONST + OP_RSHU
+ instruction += 1;
+ break;
+ }
+ }
+ if ( op1 == OP_BAND ) {
+ v = NextConstant4();
+ // try to generate shorter version
+ if ( v >= 0 && v <= 127 ) {
+ EmitString( "83 27" ); // and dword ptr[edi], 0x7F
+ Emit1( v );
+ } else {
+ EmitString( "81 27" ); // and dword ptr[edi], 0x7FFFF
+ Emit4( v );
+ }
+ pc += 5; // OP_CONST + OP_BAND
+ instruction += 1;
+ break;
+ }
+ if ( op1 == OP_BOR ) {
+ v = NextConstant4();
+ // try to generate shorter version
+ if ( v >= 0 && v <= 127 ) {
+ EmitString( "83 0F" ); // or dword ptr[edi], 0x7F
+ Emit1( v );
+ } else {
+ EmitString( "81 0F" ); // or dword ptr[edi], 0x7FFFF
+ Emit4( v );
+ }
+ pc += 5; // OP_CONST + OP_BOR
+ instruction += 1;
+ break;
+ }
+ if ( op1 == OP_JUMP ) {
+ v = Constant4();
+ JUSED(v);
+ EmitString( "FF 25" ); // jmp dword ptr [instructionPointers + 0x12345678]
+ Emit4( (intptr_t) vm->instructionPointers + v*4 );
+ pc += 1; // OP_JUMP
+ instruction += 1;
+ break;
+ }
+
+ if ( op1 == OP_CALL && NextConstant4() >= 0 ) {
+ v = Constant4();
+ JUSED(v);
+ EmitString( "FF 15" ); // call dword ptr [instructionPointers + 0x12345678]
+ Emit4( (intptr_t) vm->instructionPointers + v*4 );
+ EmitString( "8B 07" ); // mov eax, dword ptr [edi]
+ pc += 1; // OP_CALL
+ instruction += 1;
+ break;
+ }
+
EmitAddEDI4(vm);
EmitString( "C7 07" ); // mov dword ptr [edi], 0x12345678
lastConst = Constant4();
@@ -596,14 +858,10 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
case OP_ARG:
EmitMovEAXEDI(vm); // mov eax,dword ptr [edi]
EmitString( "89 86" ); // mov dword ptr [esi+database],eax
- // FIXME: range check
- Emit4( Constant1() + (int)vm->dataBase );
+ Emit4((Constant1() & vm->dataMask & 0xFF) + (int)vm->dataBase);
EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
break;
case OP_CALL:
- EmitString( "C7 86" ); // mov dword ptr [esi+database],0x12345678
- Emit4( (int)vm->dataBase );
- Emit4( pc );
EmitString( "FF 15" ); // call asmCallPtr
Emit4( (int)&asmCallPtr );
break;
@@ -1077,11 +1335,15 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
break;
case OP_JUMP:
- EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
- EmitString( "8B 47 04" ); // mov eax,dword ptr [edi+4]
- // FIXME: range check
- EmitString( "FF 24 85" ); // jmp dword ptr [instructionPointers + eax * 4]
+ EmitCommand(LAST_COMMAND_SUB_DI_4); // sub edi, 4
+ EmitString( "8B 47 04" ); // mov eax,dword ptr [edi+4]
+ EmitString( "3B 05" ); // cmp eax,[callMask]
+ Emit4( (int)&vm->instructionCount );
+ EmitString( "73 07" ); // jae +7
+ EmitString( "FF 24 85" ); // jmp dword ptr [instructionPointers + eax * 4]
Emit4( (int)vm->instructionPointers );
+ EmitString( "FF 15" ); // call errJumpPtr
+ Emit4( (int)&errJumpPtr );
break;
default:
VMFREE_BUFFERS();
@@ -1092,7 +1354,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
}
}
- // copy to an exact size buffer on the hunk
+ // 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);
@@ -1124,6 +1386,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
}
#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 );
@@ -1161,18 +1424,12 @@ int VM_CallCompiled( vm_t *vm, int *args ) {
int stackOnEntry;
byte *image;
void *opStack;
- int *oldInstructionPointers;
-
- oldInstructionPointers = instructionPointers;
currentVM = vm;
- instructionPointers = vm->instructionPointers;
// interpret the code
vm->currentlyInterpreting = qtrue;
- callMask = vm->dataMask;
-
// we might be called recursively, so this might not be the very top
programStack = vm->programStack;
stackOnEntry = programStack;
@@ -1240,8 +1497,5 @@ int VM_CallCompiled( vm_t *vm, int *args ) {
vm->programStack = stackOnEntry;
- // in case we were recursively called by another vm
- instructionPointers = oldInstructionPointers;
-
return *(int *)opStack;
}
generated by cgit (git 2.34.1) at 2024-11-18 03:17:34 +0000