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
|
/* mtrace implementation for `malloc'.
Copyright (C) 1991-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Written April 2, 1991 by John Gilmore of Cygnus Support.
Based on mcheck.c by Mike Haertel.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <malloc.h>
#include <mcheck.h>
#include <dlfcn.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <inttypes.h>
#include <libc-internal.h>
#include <dso_handle.h>
#include <kernel-features.h>
static FILE *mallstream;
static const char mallenv[] = "MALLOC_TRACE";
static void
tr_where (const void *caller, Dl_info *info)
{
if (caller != NULL)
{
if (info != NULL)
{
char *buf = (char *) "";
if (info->dli_sname != NULL)
{
size_t len = strlen (info->dli_sname);
buf = alloca (len + 6 + 2 * sizeof (void *));
char sign;
ptrdiff_t offset =
(ptrdiff_t) info->dli_saddr - (ptrdiff_t) caller;
if (caller >= (const void *) info->dli_saddr)
{
sign = '+';
offset = -offset;
}
else
sign = '-';
sprintf (buf, "(%s%c%" PRIxPTR ")", info->dli_sname, sign,
offset);
}
fprintf (mallstream, "@ %s%s%s[%p] ", info->dli_fname ? : "",
info->dli_fname ? ":" : "",
buf, caller);
}
else
fprintf (mallstream, "@ [%p] ", caller);
}
}
static Dl_info *
lock_and_info (const void *caller, Dl_info *mem)
{
if (caller == NULL)
return NULL;
Dl_info *res = dladdr (caller, mem) ? mem : NULL;
flockfile (mallstream);
return res;
}
static void
free_mtrace (void *ptr, const void *caller)
{
if (ptr == NULL)
return;
Dl_info mem;
Dl_info *info = lock_and_info (caller, &mem);
tr_where (caller, info);
/* Be sure to print it first. */
fprintf (mallstream, "- %p\n", ptr);
funlockfile (mallstream);
}
static void
malloc_mtrace_after (void *block, size_t size, const void *caller)
{
Dl_info mem;
Dl_info *info = lock_and_info (caller, &mem);
tr_where (caller, info);
/* We could be printing a NULL here; that's OK. */
fprintf (mallstream, "+ %p %#lx\n", block, (unsigned long int) size);
funlockfile (mallstream);
}
static void
realloc_mtrace_after (void *block, const void *oldptr, size_t size,
const void *caller)
{
Dl_info mem;
Dl_info *info = lock_and_info (caller, &mem);
tr_where (caller, info);
if (block == NULL)
{
if (size != 0)
/* Failed realloc. */
fprintf (mallstream, "! %p %#lx\n", oldptr, (unsigned long int) size);
else
fprintf (mallstream, "- %p\n", oldptr);
}
else if (oldptr == NULL)
fprintf (mallstream, "+ %p %#lx\n", block, (unsigned long int) size);
else
{
fprintf (mallstream, "< %p\n", oldptr);
tr_where (caller, info);
fprintf (mallstream, "> %p %#lx\n", block, (unsigned long int) size);
}
funlockfile (mallstream);
}
static void
memalign_mtrace_after (void *block, size_t size, const void *caller)
{
Dl_info mem;
Dl_info *info = lock_and_info (caller, &mem);
tr_where (caller, info);
/* We could be printing a NULL here; that's OK. */
fprintf (mallstream, "+ %p %#lx\n", block, (unsigned long int) size);
funlockfile (mallstream);
}
/* This function gets called to make sure all memory the library
allocates get freed and so does not irritate the user when studying
the mtrace output. */
static void
release_libc_mem (void)
{
/* Only call the free function if we still are running in mtrace mode. */
if (mallstream != NULL)
__libc_freeres ();
}
/* We enable tracing if the environment variable MALLOC_TRACE is set. */
static void
do_mtrace (void)
{
static int added_atexit_handler;
char *mallfile;
/* Don't panic if we're called more than once. */
if (mallstream != NULL)
return;
mallfile = secure_getenv (mallenv);
if (mallfile != NULL)
{
mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "wce");
if (mallstream != NULL)
{
/* Be sure it doesn't malloc its buffer! */
static char tracebuf [512];
setvbuf (mallstream, tracebuf, _IOFBF, sizeof (tracebuf));
fprintf (mallstream, "= Start\n");
if (!added_atexit_handler)
{
added_atexit_handler = 1;
__cxa_atexit ((void (*)(void *))release_libc_mem, NULL,
__dso_handle);
}
__malloc_debug_enable (MALLOC_MTRACE_HOOK);
}
}
}
static void
do_muntrace (void)
{
__malloc_debug_disable (MALLOC_MTRACE_HOOK);
if (mallstream == NULL)
return;
/* Do the reverse of what done in mtrace: first reset the hooks and
MALLSTREAM, and only after that write the trailer and close the
file. */
FILE *f = mallstream;
mallstream = NULL;
fprintf (f, "= End\n");
fclose (f);
}
|
