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
|
/* Standard debugging hooks for `malloc'.
Copyright (C) 1990,91,92,93,94,95,96,97,99 Free Software Foundation, Inc.
Written May 1989 by Mike Haertel.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
The author may be reached (Email) at the address mike@ai.mit.edu,
or (US mail) as Mike Haertel c/o Free Software Foundation. */
#ifndef _MALLOC_INTERNAL
# define _MALLOC_INTERNAL
# include <malloc.h>
# include <mcheck.h>
# include <stdio.h>
#endif
/* Old hook values. */
static void (*old_free_hook) __P ((__ptr_t ptr, __const __ptr_t));
static __ptr_t (*old_malloc_hook) __P ((__malloc_size_t size, const __ptr_t));
static __ptr_t (*old_realloc_hook) __P ((__ptr_t ptr, __malloc_size_t size,
__const __ptr_t));
/* Function to call when something awful happens. */
static void (*abortfunc) __P ((enum mcheck_status));
/* Arbitrary magical numbers. */
#define MAGICWORD 0xfedabeeb
#define MAGICFREE 0xd8675309
#define MAGICBYTE ((char) 0xd7)
#define MALLOCFLOOD ((char) 0x93)
#define FREEFLOOD ((char) 0x95)
struct hdr
{
__malloc_size_t size; /* Exact size requested by user. */
unsigned long int magic; /* Magic number to check header integrity. */
};
#if defined _LIBC || defined STDC_HEADERS || defined USG
# include <string.h>
# define flood memset
#else
static void flood __P ((__ptr_t, int, __malloc_size_t));
static void
flood (ptr, val, size)
__ptr_t ptr;
int val;
__malloc_size_t size;
{
char *cp = ptr;
while (size--)
*cp++ = val;
}
#endif
static enum mcheck_status checkhdr __P ((const struct hdr *));
static enum mcheck_status
checkhdr (hdr)
const struct hdr *hdr;
{
enum mcheck_status status;
switch (hdr->magic)
{
default:
status = MCHECK_HEAD;
break;
case MAGICFREE:
status = MCHECK_FREE;
break;
case MAGICWORD:
if (((char *) &hdr[1])[hdr->size] != MAGICBYTE)
status = MCHECK_TAIL;
else
status = MCHECK_OK;
break;
}
if (status != MCHECK_OK)
(*abortfunc) (status);
return status;
}
static void freehook __P ((__ptr_t, const __ptr_t));
static void
freehook (ptr, caller)
__ptr_t ptr;
const __ptr_t caller;
{
if (ptr)
{
struct hdr *hdr = ((struct hdr *) ptr) - 1;
checkhdr (hdr);
hdr->magic = MAGICFREE;
flood (ptr, FREEFLOOD, hdr->size);
ptr = (__ptr_t) hdr;
}
__free_hook = old_free_hook;
if (old_free_hook != NULL)
(*old_free_hook) (ptr, caller);
else
free (ptr);
__free_hook = freehook;
}
static __ptr_t mallochook __P ((__malloc_size_t, const __ptr_t));
static __ptr_t
mallochook (size, caller)
__malloc_size_t size;
const __ptr_t caller;
{
struct hdr *hdr;
__malloc_hook = old_malloc_hook;
if (old_malloc_hook != NULL)
hdr = (struct hdr *) (*old_malloc_hook) (sizeof (struct hdr) + size + 1,
caller);
else
hdr = (struct hdr *) malloc (sizeof (struct hdr) + size + 1);
__malloc_hook = mallochook;
if (hdr == NULL)
return NULL;
hdr->size = size;
hdr->magic = MAGICWORD;
((char *) &hdr[1])[size] = MAGICBYTE;
flood ((__ptr_t) (hdr + 1), MALLOCFLOOD, size);
return (__ptr_t) (hdr + 1);
}
static __ptr_t reallochook __P ((__ptr_t, __malloc_size_t, const __ptr_t));
static __ptr_t
reallochook (ptr, size, caller)
__ptr_t ptr;
__malloc_size_t size;
const __ptr_t caller;
{
struct hdr *hdr;
__malloc_size_t osize;
if (ptr)
{
hdr = ((struct hdr *) ptr) - 1;
osize = hdr->size;
checkhdr (hdr);
if (size < osize)
flood ((char *) ptr + size, FREEFLOOD, osize - size);
}
else
{
osize = 0;
hdr = NULL;
}
__free_hook = old_free_hook;
__malloc_hook = old_malloc_hook;
__realloc_hook = old_realloc_hook;
if (old_realloc_hook != NULL)
hdr = (struct hdr *) (*old_realloc_hook) ((__ptr_t) hdr,
sizeof (struct hdr) + size + 1,
caller);
else
hdr = (struct hdr *) realloc ((__ptr_t) hdr,
sizeof (struct hdr) + size + 1);
__free_hook = freehook;
__malloc_hook = mallochook;
__realloc_hook = reallochook;
if (hdr == NULL)
return NULL;
hdr->size = size;
hdr->magic = MAGICWORD;
((char *) &hdr[1])[size] = MAGICBYTE;
if (size > osize)
flood ((char *) (hdr + 1) + osize, MALLOCFLOOD, size - osize);
return (__ptr_t) (hdr + 1);
}
static void mabort __P ((enum mcheck_status status));
static void
mabort (status)
enum mcheck_status status;
{
const char *msg;
switch (status)
{
case MCHECK_OK:
msg = _("memory is consistent, library is buggy\n");
break;
case MCHECK_HEAD:
msg = _("memory clobbered before allocated block\n");
break;
case MCHECK_TAIL:
msg = _("memory clobbered past end of allocated block\n");
break;
case MCHECK_FREE:
msg = _("block freed twice\n");
break;
default:
msg = _("bogus mcheck_status, library is buggy\n");
break;
}
#ifdef _LIBC
__libc_fatal (msg);
#else
fprintf (stderr, "mcheck: %s", msg);
fflush (stderr);
abort ();
#endif
}
static int mcheck_used;
int
mcheck (func)
void (*func) __P ((enum mcheck_status));
{
abortfunc = (func != NULL) ? func : &mabort;
/* These hooks may not be safely inserted if malloc is already in use. */
if (__malloc_initialized <= 0 && !mcheck_used)
{
old_free_hook = __free_hook;
__free_hook = freehook;
old_malloc_hook = __malloc_hook;
__malloc_hook = mallochook;
old_realloc_hook = __realloc_hook;
__realloc_hook = reallochook;
mcheck_used = 1;
}
return mcheck_used ? 0 : -1;
}
enum mcheck_status
mprobe (__ptr_t ptr)
{
return mcheck_used ? checkhdr (((struct hdr *) ptr) - 1) : MCHECK_DISABLED;
}
|
