pred@2504: /**
pred@2504:  * vim: set ts=4 :
pred@2504:  * =============================================================================
pred@2504:  * SourceMod BinTools Extension
pred@2504:  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
pred@2504:  * =============================================================================
pred@2504:  *
pred@2504:  * This program is free software; you can redistribute it and/or modify it under
pred@2504:  * the terms of the GNU General Public License, version 3.0, as published by the
pred@2504:  * Free Software Foundation.
pred@2504:  * 
pred@2504:  * This program is distributed in the hope that it will be useful, but WITHOUT
pred@2504:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
pred@2504:  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
pred@2504:  * details.
pred@2504:  *
pred@2504:  * You should have received a copy of the GNU General Public License along with
pred@2504:  * this program.  If not, see <http://www.gnu.org/licenses/>.
pred@2504:  *
pred@2504:  * As a special exception, AlliedModders LLC gives you permission to link the
pred@2504:  * code of this program (as well as its derivative works) to "Half-Life 2," the
pred@2504:  * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
pred@2504:  * by the Valve Corporation.  You must obey the GNU General Public License in
pred@2504:  * all respects for all other code used.  Additionally, AlliedModders LLC grants
pred@2504:  * this exception to all derivative works.  AlliedModders LLC defines further
pred@2504:  * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
pred@2504:  * or <http://www.sourcemod.net/license.php>.
pred@2504:  *
pred@2504:  * Version: $Id: CallMaker.h 1964 2008-03-27 04:54:56Z damagedsoul $
pred@2504:  */
pred@2504: 
pred@2504: #if defined HOOKING_ENABLED
pred@2504: 
pred@2504: #include "jit_compile.h"
pred@2504: #include "sm_platform.h"
pred@2504: #include "extension.h"
pred@2504: 
pred@2504: /********************
pred@2504:  * Assembly Opcodes *
pred@2504:  ********************/
pred@2504: 
pred@2504: inline void Write_Function_Prologue(JitWriter *jit, bool RetInMemory)
pred@2504: {
pred@2504: 	//push ebp
pred@2504: 	//push ebx
pred@2504: 	//mov ebp, esp
pred@2504: 	IA32_Push_Reg(jit, REG_EBP);
pred@2504: 	IA32_Push_Reg(jit, REG_EBX);
pred@2504: 	IA32_Mov_Reg_Rm(jit, REG_EBP, REG_ESP, MOD_REG);
pred@2504: #if defined PLATFORM_WINDOWS
pred@2504: 	//mov ebx, ecx
pred@2504: 	IA32_Mov_Reg_Rm(jit, REG_EBX, REG_ECX, MOD_REG);
pred@2504: #elif defined PLATFORM_LINUX
pred@2504: 	//mov ebx, [ebp+12+(RetInMemory)?4:0]
pred@2504: 	IA32_Mov_Reg_Rm_Disp8(jit, REG_EBX, REG_EBP, 12+((RetInMemory)?4:0));
pred@2504: #endif
pred@2504: }
pred@2504: 
pred@2504: inline void Write_Function_Epilogue(JitWriter *jit, unsigned short size)
pred@2504: {
pred@2504: 	//mov esp, ebp
pred@2504: 	//pop ebx
pred@2504: 	//pop ebp
pred@2504: 	//ret <value>
pred@2504: 	IA32_Mov_Reg_Rm(jit, REG_ESP, REG_EBP, MOD_REG);
pred@2504: 	IA32_Pop_Reg(jit, REG_EBX);
pred@2504: 	IA32_Pop_Reg(jit, REG_EBP);
pred@2504: 	if (size == 0)
pred@2504: 	{
pred@2504: 		IA32_Return(jit);
pred@2504: 	}
pred@2504: 	else
pred@2504: 	{
pred@2504: 		IA32_Return_Popstack(jit, size);
pred@2504: 	}
pred@2504: }
pred@2504: 
pred@2504: inline void Write_Stack_Alloc(JitWriter *jit, jit_uint32_t size)
pred@2504: {
pred@2504: 	//sub esp, <value>
pred@2504: 	if (size <= SCHAR_MAX)
pred@2504: 	{
pred@2504: 		IA32_Sub_Rm_Imm8(jit, REG_ESP, (jit_int8_t)size, MOD_REG);
pred@2504: 	}
pred@2504: 	else
pred@2504: 	{
pred@2504: 		IA32_Sub_Rm_Imm32(jit, REG_ESP, size, MOD_REG);
pred@2504: 	}
pred@2504: }
pred@2504: 
pred@2504: inline void Write_Copy_Params(JitWriter *jit, bool RetInMemory, jit_uint32_t retsize, jit_uint32_t paramsize)
pred@2504: {
pred@2504: 	//:TODO: inline this memcpy!! - For small numbers of params mov's (with clever reg allocation?) would be faster
pred@2504: 
pred@2504: 	//cld
pred@2504: 	//push edi
pred@2504: 	//push esi
pred@2504: 	//lea edi, [ebp-<retsize>-<paramsize>]
pred@2504: 	//lea esi, [ebp+12+(RetInMemory)?4:0]
pred@2504: 	//if dwords
pred@2504: 	// mov ecx, <dwords>
pred@2504: 	// rep movsd
pred@2504: 	//if bytes
pred@2504: 	// mov ecx, <bytes>
pred@2504: 	// rep movsb
pred@2504: 	//pop esi
pred@2504: 	//pop edi
pred@2504: 
pred@2504: 	jit_int32_t offs;
pred@2504: 	jit_uint32_t dwords = paramsize >> 2;
pred@2504: 	jit_uint32_t bytes = paramsize & 0x3;
pred@2504: 
pred@2504: 	IA32_Cld(jit);
pred@2504: 	IA32_Push_Reg(jit, REG_EDI);
pred@2504: 	IA32_Push_Reg(jit, REG_ESI);
pred@2504: 	offs = -(jit_int32_t)retsize - paramsize;
pred@2504: 
pred@2504: 	if (offs > SCHAR_MIN)
pred@2504: 	{
pred@2504: 		IA32_Lea_DispRegImm8(jit, REG_EDI, REG_EBP, (jit_int8_t)offs);
pred@2504: 	}
pred@2504: 	else
pred@2504: 	{
pred@2504: 		IA32_Lea_DispRegImm32(jit, REG_EDI, REG_EBP, offs);
pred@2504: 	}
pred@2504: 	offs = 12 + ((RetInMemory) ? sizeof(void *) : 0);
pred@2504: 
pred@2504: #if defined PLATFORM_LINUX
pred@2504: 	offs += 4;
pred@2504: #endif
pred@2504: 
pred@2504: 	if (offs < SCHAR_MAX)
pred@2504: 	{
pred@2504: 		IA32_Lea_DispRegImm8(jit, REG_ESI, REG_EBP, (jit_int8_t)offs);
pred@2504: 	}
pred@2504: 	else
pred@2504: 	{
pred@2504: 		IA32_Lea_DispRegImm32(jit, REG_ESI, REG_EBP, offs);
pred@2504: 	}
pred@2504: 	if (dwords)
pred@2504: 	{
pred@2504: 		IA32_Mov_Reg_Imm32(jit, REG_ECX, dwords);
pred@2504: 		IA32_Rep(jit);
pred@2504: 		IA32_Movsd(jit);
pred@2504: 	}
pred@2504: 	if (bytes)
pred@2504: 	{
pred@2504: 		IA32_Mov_Reg_Imm32(jit, REG_ECX, bytes);
pred@2504: 		IA32_Rep(jit);
pred@2504: 		IA32_Movsb(jit);
pred@2504: 	}
pred@2504: 	IA32_Pop_Reg(jit, REG_ESI);
pred@2504: 	IA32_Pop_Reg(jit, REG_EDI);
pred@2504: }
pred@2504: 
pred@2504: inline void Write_Push_Params(JitWriter *jit, 
pred@2504: 							  bool isretvoid, 
pred@2504: 							  bool isvoid, 
pred@2504: 							  jit_uint32_t retsize, 
pred@2504: 							  jit_uint32_t paramsize, 
pred@2504: 							  HookWrapper *pWrapper)
pred@2504: {
pred@2504: 	//and esp, 0xFFFFFFF0
pred@2504: 	IA32_And_Rm_Imm8(jit, REG_ESP, MOD_REG, -16);
pred@2504: 
pred@2504: 	//if retvoid
pred@2504: 	// push 0
pred@2504: 	//else
pred@2504: 	// lea reg, [ebp-<retsize>]
pred@2504: 	// push reg
pred@2504: 	if (isretvoid)
pred@2504: 	{
pred@2504: 		IA32_Push_Imm8(jit, 0);
pred@2504: 	}
pred@2504: 	else
pred@2504: 	{
pred@2504: 		jit_int32_t offs = -(jit_int32_t)retsize;
pred@2504: 		if (offs >= SCHAR_MIN)
pred@2504: 		{
pred@2504: 			IA32_Lea_DispRegImm8(jit, REG_EAX, REG_EBP, (jit_int8_t)offs);
pred@2504: 		}
pred@2504: 		else
pred@2504: 		{
pred@2504: 			IA32_Lea_DispRegImm32(jit, REG_EAX, REG_EBP, offs);
pred@2504: 		}
pred@2504: 		IA32_Push_Reg(jit, REG_EAX);
pred@2504: 	}
pred@2504: 
pred@2504: 	//if void
pred@2504: 	// push 0
pred@2504: 	//else
pred@2504: 	// lea reg, [ebp-<retsize>-<paramsize>]
pred@2504: 	// push reg
pred@2504: 	if (isvoid)
pred@2504: 	{
pred@2504: 		IA32_Push_Imm8(jit, 0);
pred@2504: 	}
pred@2504: 	else
pred@2504: 	{
pred@2504: 		jit_int32_t offs = -(jit_int32_t)retsize - paramsize;
pred@2504: 		if (offs > SCHAR_MIN)
pred@2504: 		{
pred@2504: 			IA32_Lea_DispRegImm8(jit, REG_EDX, REG_EBP, (jit_int8_t)offs);
pred@2504: 		} else {
pred@2504: 			IA32_Lea_DispRegImm32(jit, REG_EDX, REG_EBP, offs);
pred@2504: 		}
pred@2504: 		IA32_Push_Reg(jit, REG_EDX);
pred@2504: 	}
pred@2504: 
pred@2504: 	//push eax (thisptr)
pred@2504: 	//IA32_Push_Reg(jit, REG_ECX);
pred@2504: 
pred@2504: 	//push ebx
pred@2504: 	IA32_Push_Reg(jit, REG_EBX);
pred@2504: 
pred@2504: 	//push <pWrapper>
pred@2504: 	IA32_Push_Imm32(jit, (jit_int32_t)pWrapper);
pred@2504: }
pred@2504: 
pred@2504: inline void Write_Call_Handler(JitWriter *jit, void *addr)
pred@2504: {
pred@2504: 	//call <addr>
pred@2504: 	jitoffs_t call = IA32_Call_Imm32(jit, 0);
pred@2504: 	IA32_Write_Jump32_Abs(jit, call, addr);
pred@2504: }
pred@2504: 
pred@2504: inline void Write_Copy_RetVal(JitWriter *jit, SourceHook::PassInfo *pRetInfo)
pred@2504: {
pred@2504: 	/* If the return value is a reference the size will probably be >sizeof(void *)
pred@2504: 	* for objects, we need to fix that so we can actually return the reference.
pred@2504: 	*/
pred@2504: 	size_t size = pRetInfo->size;
pred@2504: 	if (pRetInfo->flags & PASSFLAG_BYREF)
pred@2504: 	{
pred@2504: 		size = sizeof(void *);
pred@2504: 	}
pred@2504: 
pred@2504: 	if (pRetInfo->type == SourceHook::PassInfo::PassType_Float &&
pred@2504: 		pRetInfo->flags & SourceHook::PassInfo::PassFlag_ByVal)
pred@2504: 	{
pred@2504: 		switch (size)
pred@2504: 		{
pred@2504: 		case 4:
pred@2504: 			{
pred@2504: 				//fld DWORD PTR [ebp-4]
pred@2504: 				IA32_Fld_Mem32_Disp8(jit, REG_EBP, -4);
pred@2504: 				break;
pred@2504: 			}
pred@2504: 		case 8:
pred@2504: 			{
pred@2504: 				//fld QWORD PTR [ebp-8]
pred@2504: 				IA32_Fld_Mem64_Disp8(jit, REG_EBP, -8);
pred@2504: 				break;
pred@2504: 			}
pred@2504: 		}
pred@2504: 	}
pred@2504: 	else if (pRetInfo->type == SourceHook::PassInfo::PassType_Object &&
pred@2504: 		pRetInfo->flags & SourceHook::PassInfo::PassFlag_ByVal)
pred@2504: 	{
pred@2504: 		//cld
pred@2504: 		//push edi
pred@2504: 		//push esi
pred@2504: 		//mov edi, [ebp+12]
pred@2504: 		//lea esi, [ebp-<retsize>]
pred@2504: 		//if dwords
pred@2504: 		// mov ecx, <dwords>
pred@2504: 		// rep movsd
pred@2504: 		//if bytes
pred@2504: 		// mov ecx, <bytes>
pred@2504: 		// rep movsb
pred@2504: 		//pop esi
pred@2504: 		//pop edi
pred@2504: 
pred@2504: 		jit_int32_t offs;
pred@2504: 		jit_uint32_t dwords = size >> 2;
pred@2504: 		jit_uint32_t bytes = size & 0x3;
pred@2504: 
pred@2504: 		IA32_Cld(jit);
pred@2504: 		IA32_Push_Reg(jit, REG_EDI);
pred@2504: 		IA32_Push_Reg(jit, REG_ESI);
pred@2504: 
pred@2504: 		IA32_Mov_Reg_Rm_Disp8(jit, REG_EDI, REG_EBP, 12);
pred@2504: 
pred@2504: 		offs = -(jit_int32_t)pRetInfo->size;
pred@2504: 		if (offs >= SCHAR_MIN)
pred@2504: 		{
pred@2504: 			IA32_Lea_DispRegImm8(jit, REG_ESI, REG_EBP, (jit_int8_t)offs);
pred@2504: 		}
pred@2504: 		else
pred@2504: 		{
pred@2504: 			IA32_Lea_DispRegImm32(jit, REG_ESI, REG_EBP, offs);
pred@2504: 		}
pred@2504: 		IA32_Mov_Reg_Rm(jit, REG_EAX, REG_EDI, MOD_REG);
pred@2504: 
pred@2504: 		if (dwords)
pred@2504: 		{
pred@2504: 			IA32_Mov_Reg_Imm32(jit, REG_ECX, dwords);
pred@2504: 			IA32_Rep(jit);
pred@2504: 			IA32_Movsd(jit);
pred@2504: 		}
pred@2504: 		if (bytes)
pred@2504: 		{
pred@2504: 			IA32_Mov_Reg_Imm32(jit, REG_ECX, bytes);
pred@2504: 			IA32_Rep(jit);
pred@2504: 			IA32_Movsb(jit);
pred@2504: 		}
pred@2504: 		IA32_Pop_Reg(jit, REG_ESI);
pred@2504: 		IA32_Pop_Reg(jit, REG_EDI);
pred@2504: 	}
pred@2504: 	else
pred@2504: 	{
pred@2504: 		switch (size)
pred@2504: 		{
pred@2504: 		case 1:
pred@2504: 			{
pred@2504: 				//mov al, BYTE PTR [ebp-4]
pred@2504: 				IA32_Mov_Reg8_Rm8_Disp8(jit, REG_EAX, REG_EBP, -4);
pred@2504: 				break;
pred@2504: 			}
pred@2504: 		case 2:
pred@2504: 			{
pred@2504: 				//mov ax, WORD PTR [ebp-4]
pred@2504: 				jit->write_ubyte(IA32_16BIT_PREFIX);
pred@2504: 				IA32_Mov_Reg_Rm_Disp8(jit, REG_EAX, REG_EBP, -4);
pred@2504: 				break;
pred@2504: 			}
pred@2504: 		case 4:
pred@2504: 			{
pred@2504: 				//mov eax, DWORD PTR [ebp-4]
pred@2504: 				IA32_Mov_Reg_Rm_Disp8(jit, REG_EAX, REG_EBP, -4);
pred@2504: 				break;
pred@2504: 			}
pred@2504: 		case 8:
pred@2504: 			{
pred@2504: 				//mov eax, DWORD PTR [ebp-8]
pred@2504: 				//mov edx, DWORD PTR [ebp-4]
pred@2504: 				//:TODO: this is broken due to SH
pred@2504: 				IA32_Mov_Reg_Rm_Disp8(jit, REG_EAX, REG_EBP, -8);
pred@2504: 				IA32_Mov_Reg_Rm_Disp8(jit, REG_EDX, REG_EBP, -4);
pred@2504: 				break;
pred@2504: 			}
pred@2504: 		}
pred@2504: 	}
pred@2504: }
pred@2504: 
pred@2504: /******************************
pred@2504:  * Assembly Compiler Function *
pred@2504:  ******************************/
pred@2504: 
pred@2504: void *JIT_HookCompile(HookWrapper *pWrapper)
pred@2504: {
pred@2504: 	JitWriter writer;
pred@2504: 	JitWriter *jit = &writer;
pred@2504: 
pred@2504: 	jit_uint32_t CodeSize = 0;
pred@2504: 	jit_uint32_t ParamSize = pWrapper->GetParamSize();
pred@2504: 	jit_uint32_t RetSize = pWrapper->GetRetSize();
pred@2504: 
pred@2504: 	/* Local variable size allocated in the stack for the param and retval buffers */
pred@2504: 	jit_uint32_t LocalVarSize = ParamSize + RetSize;
pred@2504: 
pred@2504: 	/* Check if the return value is returned in memory */
pred@2504: 	bool RetInMemory = false;
pred@2504: 	SourceHook::PassInfo *pRetInfo = &pWrapper->GetProtoInfo()->retPassInfo;
pred@2504: 	if ((pRetInfo->type == SourceHook::PassInfo::PassType_Object) && 
pred@2504: 		(pRetInfo->flags & SourceHook::PassInfo::PassFlag_ByVal))
pred@2504: 	{
pred@2504: 		RetInMemory = true;
pred@2504: 	}
pred@2504: 
pred@2504: 	writer.outbase = NULL;
pred@2504: 	writer.outptr = NULL;
pred@2504: 
pred@2504: jit_rewind:
pred@2504: 	/* Write the function prologue */
pred@2504: 	Write_Function_Prologue(jit, RetInMemory);
pred@2504: 
pred@2504: 	/* Allocate the local variables into the stack */
pred@2504: 	if (LocalVarSize)
pred@2504: 	{
pred@2504: 		Write_Stack_Alloc(jit, LocalVarSize);
pred@2504: 	}
pred@2504: 
pred@2504: 	/* Copy all the parameters into the buffer */
pred@2504: 	if (ParamSize)
pred@2504: 	{
pred@2504: 		Write_Copy_Params(jit, RetInMemory, RetSize, ParamSize);
pred@2504: 	}
pred@2504: 
pred@2504: 	/* Push the parameters into the handler */
pred@2504: 	Write_Push_Params(jit, !RetSize, !ParamSize, RetSize, ParamSize, pWrapper);
pred@2504: 
pred@2504: 	/* Call the handler function */
pred@2504: 	Write_Call_Handler(jit, pWrapper->GetHandlerAddr());
pred@2504: 
pred@2504: 	/* Copy back the return value into eax or the hidden return buffer */
pred@2504: 	if (RetSize)
pred@2504: 	{
pred@2504: 		Write_Copy_RetVal(jit, pRetInfo);
pred@2504: 	}
pred@2504: 
pred@2504: 	/* Write the function epilogue */
pred@2504: 	Write_Function_Epilogue(jit, 
pred@2504: #if defined PLATFORM_WINDOWS
pred@2504: 		ParamSize + ((RetInMemory) ? sizeof(void *) : 0)
pred@2504: #elif defined PLATFORM_LINUX
pred@2504: 		(RetInMemory) ? sizeof(void *) : 0
pred@2504: #endif
pred@2504: 	);
pred@2504: 
pred@2504: 	if (writer.outbase == NULL)
pred@2504: 	{
pred@2504: 		CodeSize = writer.get_outputpos();
pred@2504: 		writer.outbase = (jitcode_t)g_SPEngine->AllocatePageMemory(CodeSize);
pred@2504: 		g_SPEngine->SetReadWrite(writer.outbase);
pred@2504: 		writer.outptr = writer.outbase;
pred@2504: 		g_RegDecoder = 0;
pred@2504: 		goto jit_rewind;
pred@2504: 	}
pred@2504: 	g_SPEngine->SetReadExecute(writer.outbase);
pred@2504: 
pred@2504: 	return writer.outbase;
pred@2504: }
pred@2504: 
pred@2504: void JIT_FreeHook(void *addr)
pred@2504: {
pred@2504: 	g_SPEngine->FreePageMemory(addr);
pred@2504: }
pred@2504: 
pred@2504: #endif