Disasm.cpp@ 239

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1	/** @file
2	*
3	* VBox disassembler:
4	* Main
5	*/
6
7	/*
8	* Copyright (C) 2006 InnoTek Systemberatung GmbH
9	*
10	* This file is part of VirtualBox Open Source Edition (OSE), as
11	* available from http://www.virtualbox.org. This file is free software;
12	* you can redistribute it and/or modify it under the terms of the GNU
13	* General Public License as published by the Free Software Foundation,
14	* in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
15	* distribution. VirtualBox OSE is distributed in the hope that it will
16	* be useful, but WITHOUT ANY WARRANTY of any kind.
17	*
18	* If you received this file as part of a commercial VirtualBox
19	* distribution, then only the terms of your commercial VirtualBox
20	* license agreement apply instead of the previous paragraph.
21	*/
22
23
24	/*******************************************************************************
25	* Header Files *
26	*******************************************************************************/
27	#ifdef USING_VISUAL_STUDIO
28	# include <stdafx.h>
29	#endif
30	#include <VBox/dis.h>
31	#include <VBox/disopcode.h>
32	#include <VBox/err.h>
33	#include <iprt/assert.h>
34	#include <iprt/string.h>
35	#include "DisasmInternal.h"
36	#include "DisasmTables.h"
37
38
39	/**
40	* Disassembles a code block.
41	*
42	* @returns Success indicator.
43	* @param pCpu Pointer to cpu structure which have DISCPUSTATE::mode
44	* set correctly.
45	* @param pvCodeBlock Pointer to the strunction to disassemble.
46	* @param cbMax Maximum number of bytes to disassemble.
47	* @param pcbSize Where to store the size of the instruction.
48	* NULL is allowed.
49	*
50	*
51	* @todo Define output callback.
52	* @todo Using signed integers as sizes is a bit odd. There are still
53	* some GCC warnings about mixing signed and unsigend integers.
54	* @todo Need to extend this interface to include a code address so we
55	* can dissassemble GC code. Perhaps a new function is better...
56	* @remark cbMax isn't respected as a boundry. DISInstr() will read beyond cbMax.
57	* This means *pcbSize >= cbMax sometimes.
58	*/
59	DISDECL(bool) DISBlock(PDISCPUSTATE pCpu, RTUINTPTR pvCodeBlock, int32_t cbMax, uint32_t *pSize)
60	{
61	int32_t i = 0;
62	char szOutput[256];
63
64	while (i < cbMax)
65	{
66	uint32_t cbInstr;
67	if (!DISInstr(pCpu, pvCodeBlock + i, 0, &cbInstr, szOutput))
68	return false;
69
70	i += cbInstr;
71	}
72
73	if (pSize)
74	*pSize = i;
75	return true;
76	}
77
78	/**
79	* Disassembles one instruction
80	*
81	* @returns Success indicator.
82	* @param pCpu Pointer to cpu structure which have DISCPUSTATE::mode
83	* set correctly.
84	* @param pu8Instruction Pointer to the strunction to disassemble.
85	* @param u32EipOffset Offset to add to instruction address to get the real virtual address
86	* @param pcbSize Where to store the size of the instruction.
87	* NULL is allowed.
88	* @param pszOutput Storage for disassembled instruction
89	*
90	* @todo Define output callback.
91	*/
92	DISDECL(bool) DISInstr(PDISCPUSTATE pCpu, RTUINTPTR pu8Instruction, uint32_t u32EipOffset, uint32_t *pcbSize,
93	char *pszOutput)
94	{
95	return DISInstrEx(pCpu, pu8Instruction, u32EipOffset, pcbSize, pszOutput, OPTYPE_ALL);
96	}
97
98	/**
99	* Disassembles one instruction; only fully disassembly an instruction if it matches the filter criteria
100	*
101	* @returns Success indicator.
102	* @param pCpu Pointer to cpu structure which have DISCPUSTATE::mode
103	* set correctly.
104	* @param pu8Instruction Pointer to the strunction to disassemble.
105	* @param u32EipOffset Offset to add to instruction address to get the real virtual address
106	* @param pcbSize Where to store the size of the instruction.
107	* NULL is allowed.
108	* @param pszOutput Storage for disassembled instruction
109	* @param uFilter Instruction type filter
110	*
111	* @todo Define output callback.
112	*/
113	DISDECL(bool) DISInstrEx(PDISCPUSTATE pCpu, RTUINTPTR pu8Instruction, uint32_t u32EipOffset, uint32_t *pcbSize,
114	char *pszOutput, uint32_t uFilter)
115	{
116	int i = 0, prefixbytes;
117	int idx, inc;
118	#ifdef __L4ENV__
119	jmp_buf jumpbuffer;
120	#endif
121
122	//reset instruction settings
123	pCpu->prefix = PREFIX_NONE;
124	pCpu->prefix_seg = 0;
125	pCpu->addrmode = pCpu->mode;
126	pCpu->opmode = pCpu->mode;
127	pCpu->ModRM = 0;
128	pCpu->SIB = 0;
129	pCpu->lastprefix = 0;
130	pCpu->param1.parval = 0;
131	pCpu->param2.parval = 0;
132	pCpu->param3.parval = 0;
133	pCpu->param1.szParam[0] = 0;
134	pCpu->param2.szParam[0] = 0;
135	pCpu->param3.szParam[0] = 0;
136	pCpu->param1.size = 0;
137	pCpu->param2.size = 0;
138	pCpu->param3.size = 0;
139	pCpu->param1.flags = 0;
140	pCpu->param2.flags = 0;
141	pCpu->param3.flags = 0;
142	pCpu->uFilter = uFilter;
143	pCpu->pfnDisasmFnTable = pfnFullDisasm;
144
145	if (pszOutput)
146	*pszOutput = '\0';
147
148	prefixbytes = 0;
149	#ifndef __L4ENV__ /* Unfortunately, we have no exception handling in l4env */
150	try
151	#else
152	pCpu->pJumpBuffer = &jumpbuffer;
153	if (setjmp(jumpbuffer) == 0)
154	#endif
155	{
156	while(1)
157	{
158	uint8_t codebyte = DISReadByte(pCpu, pu8Instruction+i);
159	uint8_t opcode = g_aOneByteMapX86[codebyte].opcode;
160
161	/* Hardcoded assumption about OP_* values!! */
162	if (opcode <= OP_LOCK)
163	{
164	pCpu->lastprefix = opcode;
165	switch(opcode)
166	{
167	case OP_INVALID:
168	#if 0 //defined (DEBUG_Sander)
169	AssertMsgFailed(("Invalid opcode!!\n"));
170	#endif
171	return false;
172
173	// segment override prefix byte
174	case OP_SEG:
175	pCpu->prefix_seg = g_aOneByteMapX86[codebyte].param1 - OP_PARM_REG_SEG_START;
176	pCpu->prefix \|= PREFIX_SEG;
177	i += sizeof(uint8_t);
178	prefixbytes++;
179	continue; //fetch the next byte
180
181	// lock prefix byte
182	case OP_LOCK:
183	pCpu->prefix \|= PREFIX_LOCK;
184	i += sizeof(uint8_t);
185	prefixbytes++;
186	continue; //fetch the next byte
187
188	// address size override prefix byte
189	case OP_ADRSIZE:
190	pCpu->prefix \|= PREFIX_ADDRSIZE;
191	if(pCpu->mode == CPUMODE_16BIT)
192	pCpu->addrmode = CPUMODE_32BIT;
193	else pCpu->addrmode = CPUMODE_16BIT;
194	i += sizeof(uint8_t);
195	prefixbytes++;
196	continue; //fetch the next byte
197
198	// operand size override prefix byte
199	case OP_OPSIZE:
200	pCpu->prefix \|= PREFIX_OPSIZE;
201	if(pCpu->mode == CPUMODE_16BIT)
202	pCpu->opmode = CPUMODE_32BIT;
203	else pCpu->opmode = CPUMODE_16BIT;
204	i += sizeof(uint8_t);
205	prefixbytes++;
206	continue; //fetch the next byte
207
208	// rep and repne are not really prefixes, but we'll treat them as such
209	case OP_REPE:
210	pCpu->prefix \|= PREFIX_REP;
211	i += sizeof(uint8_t);
212	prefixbytes += sizeof(uint8_t);
213	continue; //fetch the next byte
214
215	case OP_REPNE:
216	pCpu->prefix \|= PREFIX_REPNE;
217	i += sizeof(uint8_t);
218	prefixbytes += sizeof(uint8_t);
219	continue; //fetch the next byte
220	}
221	}
222
223	idx = i;
224	i += sizeof(uint8_t); //first opcode byte
225
226	pCpu->opcode = codebyte;
227	/* Prefix byte(s) is/are part of the instruction. */
228	pCpu->opaddr = pu8Instruction + idx + u32EipOffset - prefixbytes;
229
230	inc = ParseInstruction(pu8Instruction + i, &g_aOneByteMapX86[pCpu->opcode], pCpu);
231
232	pCpu->opsize = prefixbytes + inc + sizeof(uint8_t);
233
234	if(pszOutput) {
235	disasmSprintf(pszOutput, pu8Instruction+i-1-prefixbytes, pCpu, &pCpu->param1, &pCpu->param2, &pCpu->param3);
236	}
237
238	i += inc;
239	prefixbytes = 0;
240	break;
241	}
242	}
243	#ifndef __L4ENV__
244	catch(...)
245	#else
246	else /* setjmp has returned a non-zero value: an exception occured */
247	#endif
248	{
249	if (pcbSize)
250	*pcbSize = 0;
251	return false;
252	}
253
254	if (pcbSize)
255	*pcbSize = i;
256
257	return true;
258	}
259	//*****************************************************************************
260	//*****************************************************************************
261	char DbgBytesToString(PDISCPUSTATE pCpu, RTUINTPTR pBytes, int size, char pszOutput)
262	{
263	char szByte[4];
264	int len = strlen(pszOutput);
265	int i;
266
267	for(i = len; i < 40; i++)
268	{
269	strcat(pszOutput, " ");
270	}
271	strcat(pszOutput, " [");
272	for(i = 0; i < size; i++)
273	{
274	RTStrPrintf(szByte, sizeof(szByte), "%02X ", DISReadByte(pCpu, pBytes+i));
275	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, szByte);
276	}
277	len = strlen(pszOutput);
278	pszOutput[len - 1] = 0; //cut off last space
279
280	strcat(pszOutput, "]");
281	return pszOutput;
282	}
283	//*****************************************************************************
284	//*****************************************************************************
285	void disasmSprintf(char pszOutput, RTUINTPTR pu8Instruction, PDISCPUSTATE pCpu, OP_PARAMETER pParam1, OP_PARAMETER pParam2, OP_PARAMETER pParam3)
286	{
287	char *lpszFormat = pCpu->pszOpcode;
288	int param = 1;
289
290	RTStrPrintf(pszOutput, 64, "%08X: ", (unsigned)pCpu->opaddr);
291	if(pCpu->prefix & PREFIX_LOCK)
292	{
293	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "lock ");
294	}
295	if(pCpu->prefix & PREFIX_REP)
296	{
297	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "rep(e) ");
298	}
299	else
300	if(pCpu->prefix & PREFIX_REPNE)
301	{
302	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "repne ");
303	}
304
305	if(!strcmp("Invalid Opcode", lpszFormat))
306	{
307	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "Invalid Opcode [%02X][%02X]", DISReadByte(pCpu, pu8Instruction), DISReadByte(pCpu, pu8Instruction+1) );
308	}
309	else
310	while(*lpszFormat)
311	{
312	switch(*lpszFormat)
313	{
314	case '%':
315	switch(*(lpszFormat+1))
316	{
317	case 'J': //Relative jump offset
318	{
319	int32_t disp;
320
321	AssertMsg(param == 1, ("Invalid branch parameter nr"));
322	if(pParam1->flags & USE_IMMEDIATE8_REL)
323	{
324	disp = (int32_t)(char)pParam1->parval;
325	}
326	else
327	if(pParam1->flags & USE_IMMEDIATE16_REL)
328	{
329	disp = (int32_t)(uint16_t)pParam1->parval;
330	}
331	else
332	if(pParam1->flags & USE_IMMEDIATE32_REL)
333	{
334	disp = (int32_t)pParam1->parval;
335	}
336	else
337	{
338	AssertMsgFailed(("Oops!\n"));
339	return;
340	}
341	uint32_t addr = (uint32_t)(pCpu->opaddr + pCpu->opsize) + disp;
342	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "[%08X]", addr);
343	}
344
345	//no break;
346
347	case 'A': //direct address
348	case 'C': //control register
349	case 'D': //debug register
350	case 'E': //ModRM specifies parameter
351	case 'F': //Eflags register
352	case 'G': //ModRM selects general register
353	case 'I': //Immediate data
354	case 'M': //ModRM may only refer to memory
355	case 'O': //No ModRM byte
356	case 'P': //ModRM byte selects MMX register
357	case 'Q': //ModRM byte selects MMX register or memory address
358	case 'R': //ModRM byte may only refer to a general register
359	case 'S': //ModRM byte selects a segment register
360	case 'T': //ModRM byte selects a test register
361	case 'V': //ModRM byte selects an XMM/SSE register
362	case 'W': //ModRM byte selects an XMM/SSE register or a memory address
363	case 'X': //DS:SI
364	case 'Y': //ES:DI
365	switch(param)
366	{
367	case 1:
368	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, pParam1->szParam);
369	break;
370	case 2:
371	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, pParam2->szParam);
372	break;
373	case 3:
374	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, pParam3->szParam);
375	break;
376	}
377	break;
378
379	case 'e': //register based on operand size (e.g. %eAX)
380	if(pCpu->opmode == CPUMODE_32BIT)
381	{
382	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "E");
383	}
384	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "%c%c", lpszFormat[2], lpszFormat[3]);
385	break;
386
387	default:
388	AssertMsgFailed(("Oops!\n"));
389	break;
390	}
391
392	//Go to the next parameter in the format string
393	while(lpszFormat && lpszFormat != ',') lpszFormat++;
394	if(*lpszFormat == ',') lpszFormat--;
395
396	break;
397
398	case ',':
399	param++;
400	//no break
401
402	default:
403	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "%c", *lpszFormat);
404	break;
405	}
406
407	if(*lpszFormat) lpszFormat++;
408	}
409	DbgBytesToString(pCpu, pu8Instruction, pCpu->opsize, pszOutput);
410	RTStrPrintf(&pszOutput[strlen(pszOutput)], 64, "\n");
411	}
412	//*****************************************************************************
413	//*****************************************************************************

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source: vbox/trunk/src/VBox/Disassembler/Disasm.cpp@ 239

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