1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
|
/*
* Debugger memory handling
*
* Copyright 1993 Eric Youngdale
* Copyright 1995 Alexandre Julliard
*/
#include <stdio.h>
#include <stdlib.h>
#include "windows.h"
#include "debugger.h"
/************************************************************
*
* Check if linear pointer in [addr, addr+size[
* read (rwflag == 1)
* or
* write (rwflag == 0)
************************************************************/
#ifdef linux
BOOL32 DEBUG_checkmap_bad( const char *addr, size_t size, int rwflag)
{
FILE *fp;
char buf[80]; /* temporary line buffer */
char prot[5]; /* protection string */
char *start, *end;
int ret = TRUE;
/*
The entries in /proc/self/maps are of the form:
08000000-08002000 r-xp 00000000 03:41 2361
08002000-08003000 rw-p 00001000 03:41 2361
08003000-08005000 rwxp 00000000 00:00 0
40000000-40005000 r-xp 00000000 03:41 67219
40005000-40006000 rw-p 00004000 03:41 67219
40006000-40007000 rw-p 00000000 00:00 0
...
start end perm ??? major:minor inode
Only permissions start and end are used here
*/
if (!(fp = fopen("/proc/self/maps", "r")))
return FALSE;
while (fgets( buf, 79, fp)) {
sscanf(buf, "%x-%x %3s", (int *) &start, (int *) &end, prot);
if ( end < addr)
continue;
if (start <= addr && addr+size < end) {
if (rwflag)
ret = (prot[0] != 'r'); /* test for reading */
else
ret = (prot[1] != 'w'); /* test for writing */
}
break;
}
fclose( fp);
return ret;
}
#else /* linux */
/* FIXME: code needed for BSD et al. */
BOOL32 DEBUG_checkmap_bad(char *addr, size_t size, int rwflag)
{
return FALSE;
}
#endif /* linux */
/***********************************************************************
* DEBUG_IsBadReadPtr
*
* Check if we are allowed to read memory at 'address'.
*/
BOOL32 DEBUG_IsBadReadPtr( const DBG_ADDR *address, int size )
{
if (address->seg) /* segmented addr */
{
if (IsBadReadPtr16( (SEGPTR)MAKELONG( (WORD)address->off,
(WORD)address->seg ), size ))
return TRUE;
}
return DEBUG_checkmap_bad( DBG_ADDR_TO_LIN(address), size, 1);
}
/***********************************************************************
* DEBUG_IsBadWritePtr
*
* Check if we are allowed to write memory at 'address'.
*/
BOOL32 DEBUG_IsBadWritePtr( const DBG_ADDR *address, int size )
{
if (address->seg) /* segmented addr */
{
/* Note: we use IsBadReadPtr here because we are */
/* always allowed to write to read-only segments */
if (IsBadReadPtr16( (SEGPTR)MAKELONG( (WORD)address->off,
(WORD)address->seg ), size ))
return TRUE;
}
return DEBUG_checkmap_bad( DBG_ADDR_TO_LIN(address), size, 0);
}
/***********************************************************************
* DEBUG_ReadMemory
*
* Read a memory value.
*/
int DEBUG_ReadMemory( const DBG_ADDR *address )
{
DBG_ADDR addr = *address;
DBG_FIX_ADDR_SEG( &addr, DS_reg(&DEBUG_context) );
if (!DBG_CHECK_READ_PTR( &addr, sizeof(int) )) return 0;
return *(int *)DBG_ADDR_TO_LIN( &addr );
}
/***********************************************************************
* DEBUG_WriteMemory
*
* Store a value in memory.
*/
void DEBUG_WriteMemory( const DBG_ADDR *address, int value )
{
DBG_ADDR addr = *address;
DBG_FIX_ADDR_SEG( &addr, DS_reg(&DEBUG_context) );
if (!DBG_CHECK_WRITE_PTR( &addr, sizeof(int) )) return;
*(int *)DBG_ADDR_TO_LIN( &addr ) = value;
}
/***********************************************************************
* DEBUG_ExamineMemory
*
* Implementation of the 'x' command.
*/
void DEBUG_ExamineMemory( const DBG_ADDR *address, int count, char format )
{
DBG_ADDR addr = * address;
unsigned int * dump;
int i;
unsigned char * pnt;
unsigned int seg2;
struct datatype * testtype;
unsigned short int * wdump;
DBG_FIX_ADDR_SEG( &addr, (format == 'i') ?
CS_reg(&DEBUG_context) : DS_reg(&DEBUG_context) );
/*
* Dereference pointer to get actual memory address we need to be
* reading. We will use the same segment as what we have already,
* and hope that this is a sensible thing to do.
*/
if( addr.type != NULL )
{
if( addr.type == DEBUG_TypeIntConst )
{
/*
* We know that we have the actual offset stored somewhere
* else in 32-bit space. Grab it, and we
* should be all set.
*/
seg2 = addr.seg;
addr.seg = 0;
addr.off = DEBUG_GetExprValue(&addr, NULL);
addr.seg = seg2;
}
else
{
if (!DBG_CHECK_READ_PTR( &addr, 1 )) return;
DEBUG_TypeDerefPointer(&addr, &testtype);
if( testtype != NULL || addr.type == DEBUG_TypeIntConst )
{
addr.off = DEBUG_GetExprValue(&addr, NULL);
}
}
}
else if (!addr.seg && !addr.off)
{
fprintf(stderr,"Invalid expression\n");
return;
}
if (format != 'i' && count > 1)
{
DEBUG_PrintAddress( &addr, dbg_mode, FALSE );
fprintf(stderr,": ");
}
pnt = DBG_ADDR_TO_LIN( &addr );
switch(format)
{
case 's':
if (count == 1) count = 256;
while (count--)
{
if (!DBG_CHECK_READ_PTR( &addr, sizeof(char) )) return;
if (!*pnt) break;
addr.off++;
fputc( *pnt++, stderr );
}
fprintf(stderr,"\n");
return;
case 'i':
while (count--)
{
DEBUG_PrintAddress( &addr, dbg_mode, TRUE );
fprintf(stderr,": ");
if (!DBG_CHECK_READ_PTR( &addr, 1 )) return;
DEBUG_Disasm( &addr, TRUE );
fprintf(stderr,"\n");
}
return;
case 'x':
dump = (unsigned int *)pnt;
for(i=0; i<count; i++)
{
if (!DBG_CHECK_READ_PTR( &addr, sizeof(int) )) return;
fprintf(stderr," %8.8x", *dump++);
addr.off += sizeof(int);
if ((i % 8) == 7)
{
fprintf(stderr,"\n");
DEBUG_PrintAddress( &addr, dbg_mode, FALSE );
fprintf(stderr,": ");
}
}
fprintf(stderr,"\n");
return;
case 'd':
dump = (unsigned int *)pnt;
for(i=0; i<count; i++)
{
if (!DBG_CHECK_READ_PTR( &addr, sizeof(int) )) return;
fprintf(stderr," %d", *dump++);
addr.off += sizeof(int);
if ((i % 8) == 7)
{
fprintf(stderr,"\n");
DEBUG_PrintAddress( &addr, dbg_mode, FALSE );
fprintf(stderr,": ");
}
}
fprintf(stderr,"\n");
return;
case 'w':
wdump = (unsigned short *)pnt;
for(i=0; i<count; i++)
{
if (!DBG_CHECK_READ_PTR( &addr, sizeof(short) )) return;
fprintf(stderr," %04x", *wdump++);
addr.off += sizeof(short);
if ((i % 8) == 7)
{
fprintf(stderr,"\n");
DEBUG_PrintAddress( &addr, dbg_mode, FALSE );
fprintf(stderr,": ");
}
}
fprintf(stderr,"\n");
return;
case 'c':
for(i=0; i<count; i++)
{
if (!DBG_CHECK_READ_PTR( &addr, sizeof(char) )) return;
if(*pnt < 0x20)
{
fprintf(stderr," ");
pnt++;
}
else fprintf(stderr," %c", *pnt++);
addr.off++;
if ((i % 32) == 31)
{
fprintf(stderr,"\n");
DEBUG_PrintAddress( &addr, dbg_mode, FALSE );
fprintf(stderr,": ");
}
}
fprintf(stderr,"\n");
return;
case 'b':
for(i=0; i<count; i++)
{
if (!DBG_CHECK_READ_PTR( &addr, sizeof(char) )) return;
fprintf(stderr," %02x", (*pnt++) & 0xff);
addr.off++;
if ((i % 16) == 15)
{
fprintf(stderr,"\n");
DEBUG_PrintAddress( &addr, dbg_mode, FALSE );
fprintf(stderr,": ");
}
}
fprintf(stderr,"\n");
return;
}
}
|
