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6d52618b | 1 | /* More debugging hooks for `malloc'. |
77fe0b9c | 2 | Copyright (C) 1991-1994,1996-2001,2002 Free Software Foundation, Inc. |
41bdb6e2 | 3 | This file is part of the GNU C Library. |
6d52618b UD |
4 | Written April 2, 1991 by John Gilmore of Cygnus Support. |
5 | Based on mcheck.c by Mike Haertel. | |
6 | ||
41bdb6e2 AJ |
7 | The GNU C Library is free software; you can redistribute it and/or |
8 | modify it under the terms of the GNU Lesser General Public | |
9 | License as published by the Free Software Foundation; either | |
10 | version 2.1 of the License, or (at your option) any later version. | |
6d52618b | 11 | |
41bdb6e2 | 12 | The GNU C Library is distributed in the hope that it will be useful, |
6d52618b UD |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41bdb6e2 | 15 | Lesser General Public License for more details. |
6d52618b | 16 | |
41bdb6e2 AJ |
17 | You should have received a copy of the GNU Lesser General Public |
18 | License along with the GNU C Library; if not, write to the Free | |
19 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
20 | 02111-1307 USA. */ | |
6d52618b UD |
21 | |
22 | #ifndef _MALLOC_INTERNAL | |
23 | #define _MALLOC_INTERNAL | |
24 | #include <malloc.h> | |
25 | #include <mcheck.h> | |
5107cf1d | 26 | #include <bits/libc-lock.h> |
6d52618b UD |
27 | #endif |
28 | ||
b3fc5f84 | 29 | #include <dlfcn.h> |
755104ed | 30 | #include <fcntl.h> |
6d52618b | 31 | #include <stdio.h> |
e03c3361 | 32 | #include <string.h> |
6d52618b | 33 | #include <stdlib.h> |
6d52618b | 34 | |
d5cabaa4 UD |
35 | #include <stdio-common/_itoa.h> |
36 | ||
66539a73 AJ |
37 | #ifdef _LIBC |
38 | # include <libc-internal.h> | |
39 | #endif | |
40 | ||
d5cabaa4 | 41 | #ifdef USE_IN_LIBIO |
08a0d60a | 42 | # include <libio/iolibio.h> |
4c48dc93 | 43 | # define fopen(f, n) _IO_fopen64 (f, n) |
77fe0b9c | 44 | # define setvbuf(s, b, f, l) INTUSE(_IO_setvbuf) (s, b, f, l) |
50304ef0 UD |
45 | #endif |
46 | ||
e7993f20 UD |
47 | #define TRACE_BUFFER_SIZE 512 |
48 | ||
6d52618b | 49 | static FILE *mallstream; |
bd355af0 | 50 | static const char mallenv[]= "MALLOC_TRACE"; |
e7993f20 | 51 | static char malloc_trace_buffer[TRACE_BUFFER_SIZE]; |
6d52618b UD |
52 | |
53 | __libc_lock_define_initialized (static, lock); | |
54 | ||
55 | /* Address to breakpoint on accesses to... */ | |
56 | __ptr_t mallwatch; | |
57 | ||
58 | /* File name and line number information, for callers that had | |
59 | the foresight to call through a macro. */ | |
60 | char *_mtrace_file; | |
61 | int _mtrace_line; | |
62 | ||
63 | /* Old hook values. */ | |
a2b08ee5 UD |
64 | static void (*tr_old_free_hook) __P ((__ptr_t ptr, const __ptr_t)); |
65 | static __ptr_t (*tr_old_malloc_hook) __P ((__malloc_size_t size, | |
66 | const __ptr_t)); | |
67 | static __ptr_t (*tr_old_realloc_hook) __P ((__ptr_t ptr, | |
68 | __malloc_size_t size, | |
69 | const __ptr_t)); | |
6d52618b UD |
70 | |
71 | /* This function is called when the block being alloc'd, realloc'd, or | |
72 | freed has an address matching the variable "mallwatch". In a debugger, | |
73 | set "mallwatch" to the address of interest, then put a breakpoint on | |
74 | tr_break. */ | |
75 | ||
76 | void tr_break __P ((void)); | |
77 | void | |
78 | tr_break () | |
79 | { | |
80 | } | |
81 | ||
dfd2257a | 82 | static void tr_where __P ((const __ptr_t)) internal_function; |
6d52618b | 83 | static void |
dfd2257a | 84 | internal_function |
a2b08ee5 UD |
85 | tr_where (caller) |
86 | const __ptr_t caller; | |
6d52618b UD |
87 | { |
88 | if (_mtrace_file) | |
89 | { | |
90 | fprintf (mallstream, "@ %s:%d ", _mtrace_file, _mtrace_line); | |
91 | _mtrace_file = NULL; | |
92 | } | |
a2b08ee5 UD |
93 | else if (caller != NULL) |
94 | { | |
95 | #ifdef HAVE_ELF | |
96 | Dl_info info; | |
97 | if (_dl_addr (caller, &info)) | |
98 | { | |
604510f7 | 99 | char *buf = (char *) ""; |
46b05e5d | 100 | if (info.dli_sname != NULL) |
604510f7 | 101 | { |
d5cabaa4 UD |
102 | size_t len = strlen (info.dli_sname); |
103 | buf = alloca (len + 6 + 2 * sizeof (void *)); | |
104 | ||
105 | buf[0] = '('; | |
106 | __stpcpy (_fitoa (caller >= (const __ptr_t) info.dli_saddr | |
107 | ? caller - (const __ptr_t) info.dli_saddr | |
108 | : (const __ptr_t) info.dli_saddr - caller, | |
109 | __stpcpy (__mempcpy (buf + 1, info.dli_sname, | |
110 | len), | |
111 | caller >= (__ptr_t) info.dli_saddr | |
112 | ? "+0x" : "-0x"), | |
113 | 16, 0), | |
114 | ")"); | |
604510f7 UD |
115 | } |
116 | ||
117 | fprintf (mallstream, "@ %s%s%s[%p] ", | |
a2b08ee5 | 118 | info.dli_fname ?: "", info.dli_fname ? ":" : "", |
604510f7 | 119 | buf, caller); |
a2b08ee5 UD |
120 | } |
121 | else | |
122 | #endif | |
123 | fprintf (mallstream, "@ [%p] ", caller); | |
124 | } | |
6d52618b UD |
125 | } |
126 | ||
a2b08ee5 | 127 | static void tr_freehook __P ((__ptr_t, const __ptr_t)); |
6d52618b | 128 | static void |
a2b08ee5 | 129 | tr_freehook (ptr, caller) |
6d52618b | 130 | __ptr_t ptr; |
a2b08ee5 | 131 | const __ptr_t caller; |
6d52618b | 132 | { |
55465bd9 UD |
133 | if (ptr == NULL) |
134 | return; | |
92e4472f | 135 | __libc_lock_lock (lock); |
a2b08ee5 UD |
136 | tr_where (caller); |
137 | /* Be sure to print it first. */ | |
138 | fprintf (mallstream, "- %p\n", ptr); | |
92e4472f | 139 | __libc_lock_unlock (lock); |
6d52618b UD |
140 | if (ptr == mallwatch) |
141 | tr_break (); | |
142 | __libc_lock_lock (lock); | |
143 | __free_hook = tr_old_free_hook; | |
a2b08ee5 UD |
144 | if (tr_old_free_hook != NULL) |
145 | (*tr_old_free_hook) (ptr, caller); | |
146 | else | |
147 | free (ptr); | |
6d52618b UD |
148 | __free_hook = tr_freehook; |
149 | __libc_lock_unlock (lock); | |
150 | } | |
151 | ||
a2b08ee5 | 152 | static __ptr_t tr_mallochook __P ((__malloc_size_t, const __ptr_t)); |
6d52618b | 153 | static __ptr_t |
a2b08ee5 | 154 | tr_mallochook (size, caller) |
6d52618b | 155 | __malloc_size_t size; |
a2b08ee5 | 156 | const __ptr_t caller; |
6d52618b UD |
157 | { |
158 | __ptr_t hdr; | |
159 | ||
160 | __libc_lock_lock (lock); | |
161 | ||
162 | __malloc_hook = tr_old_malloc_hook; | |
a2b08ee5 UD |
163 | if (tr_old_malloc_hook != NULL) |
164 | hdr = (__ptr_t) (*tr_old_malloc_hook) (size, caller); | |
165 | else | |
166 | hdr = (__ptr_t) malloc (size); | |
6d52618b UD |
167 | __malloc_hook = tr_mallochook; |
168 | ||
a2b08ee5 | 169 | tr_where (caller); |
6d52618b | 170 | /* We could be printing a NULL here; that's OK. */ |
c0fb8a56 | 171 | fprintf (mallstream, "+ %p %#lx\n", hdr, (unsigned long int) size); |
6d52618b | 172 | |
92e4472f UD |
173 | __libc_lock_unlock (lock); |
174 | ||
6d52618b UD |
175 | if (hdr == mallwatch) |
176 | tr_break (); | |
177 | ||
178 | return hdr; | |
179 | } | |
180 | ||
a2b08ee5 | 181 | static __ptr_t tr_reallochook __P ((__ptr_t, __malloc_size_t, const __ptr_t)); |
6d52618b | 182 | static __ptr_t |
a2b08ee5 | 183 | tr_reallochook (ptr, size, caller) |
6d52618b UD |
184 | __ptr_t ptr; |
185 | __malloc_size_t size; | |
a2b08ee5 | 186 | const __ptr_t caller; |
6d52618b UD |
187 | { |
188 | __ptr_t hdr; | |
189 | ||
190 | if (ptr == mallwatch) | |
191 | tr_break (); | |
192 | ||
193 | __libc_lock_lock (lock); | |
194 | ||
195 | __free_hook = tr_old_free_hook; | |
196 | __malloc_hook = tr_old_malloc_hook; | |
197 | __realloc_hook = tr_old_realloc_hook; | |
a2b08ee5 UD |
198 | if (tr_old_realloc_hook != NULL) |
199 | hdr = (__ptr_t) (*tr_old_realloc_hook) (ptr, size, caller); | |
200 | else | |
201 | hdr = (__ptr_t) realloc (ptr, size); | |
6d52618b UD |
202 | __free_hook = tr_freehook; |
203 | __malloc_hook = tr_mallochook; | |
204 | __realloc_hook = tr_reallochook; | |
205 | ||
a2b08ee5 | 206 | tr_where (caller); |
6d52618b UD |
207 | if (hdr == NULL) |
208 | /* Failed realloc. */ | |
c0fb8a56 | 209 | fprintf (mallstream, "! %p %#lx\n", ptr, (unsigned long int) size); |
6d52618b | 210 | else if (ptr == NULL) |
c0fb8a56 | 211 | fprintf (mallstream, "+ %p %#lx\n", hdr, (unsigned long int) size); |
6d52618b | 212 | else |
8261bc4b UD |
213 | { |
214 | fprintf (mallstream, "< %p\n", ptr); | |
215 | tr_where (caller); | |
216 | fprintf (mallstream, "> %p %#lx\n", hdr, (unsigned long int) size); | |
217 | } | |
6d52618b | 218 | |
92e4472f UD |
219 | __libc_lock_unlock (lock); |
220 | ||
6d52618b UD |
221 | if (hdr == mallwatch) |
222 | tr_break (); | |
223 | ||
224 | return hdr; | |
225 | } | |
226 | ||
a5a0310d UD |
227 | |
228 | #ifdef _LIBC | |
a5a0310d UD |
229 | |
230 | /* This function gets called to make sure all memory the library | |
231 | allocates get freed and so does not irritate the user when studying | |
232 | the mtrace output. */ | |
233 | static void | |
234 | release_libc_mem (void) | |
235 | { | |
236 | /* Only call the free function if we still are running in mtrace mode. */ | |
237 | if (mallstream != NULL) | |
238 | __libc_freeres (); | |
239 | } | |
240 | #endif | |
241 | ||
242 | ||
6d52618b UD |
243 | /* We enable tracing if either the environment variable MALLOC_TRACE |
244 | is set, or if the variable mallwatch has been patched to an address | |
245 | that the debugging user wants us to stop on. When patching mallwatch, | |
246 | don't forget to set a breakpoint on tr_break! */ | |
247 | ||
248 | void | |
249 | mtrace () | |
250 | { | |
a5a0310d | 251 | #ifdef _LIBC |
c4563d2d | 252 | static int added_atexit_handler; |
a5a0310d | 253 | #endif |
6d52618b UD |
254 | char *mallfile; |
255 | ||
256 | /* Don't panic if we're called more than once. */ | |
257 | if (mallstream != NULL) | |
258 | return; | |
259 | ||
260 | #ifdef _LIBC | |
261 | /* When compiling the GNU libc we use the secure getenv function | |
262 | which prevents the misuse in case of SUID or SGID enabled | |
263 | programs. */ | |
264 | mallfile = __secure_getenv (mallenv); | |
265 | #else | |
266 | mallfile = getenv (mallenv); | |
267 | #endif | |
268 | if (mallfile != NULL || mallwatch != NULL) | |
269 | { | |
4c48dc93 | 270 | mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "w"); |
6d52618b UD |
271 | if (mallstream != NULL) |
272 | { | |
755104ed UD |
273 | /* Make sure we close the file descriptor on exec. */ |
274 | int flags = __fcntl (fileno (mallstream), F_GETFD, 0); | |
275 | if (flags >= 0) | |
276 | { | |
277 | flags |= FD_CLOEXEC; | |
278 | __fcntl (fileno (mallstream), F_SETFD, flags); | |
279 | } | |
6d52618b | 280 | /* Be sure it doesn't malloc its buffer! */ |
479e9b3f | 281 | setvbuf (mallstream, malloc_trace_buffer, _IOFBF, TRACE_BUFFER_SIZE); |
6d52618b UD |
282 | fprintf (mallstream, "= Start\n"); |
283 | tr_old_free_hook = __free_hook; | |
284 | __free_hook = tr_freehook; | |
285 | tr_old_malloc_hook = __malloc_hook; | |
286 | __malloc_hook = tr_mallochook; | |
287 | tr_old_realloc_hook = __realloc_hook; | |
288 | __realloc_hook = tr_reallochook; | |
a5a0310d UD |
289 | #ifdef _LIBC |
290 | if (!added_atexit_handler) | |
291 | { | |
c08bc50a | 292 | extern void *__dso_handle __attribute__ ((__weak__)); |
a5a0310d | 293 | added_atexit_handler = 1; |
c08bc50a UD |
294 | __cxa_atexit ((void (*) (void *)) release_libc_mem, NULL, |
295 | &__dso_handle ? __dso_handle : NULL); | |
a5a0310d UD |
296 | } |
297 | #endif | |
6d52618b UD |
298 | } |
299 | } | |
300 | } | |
301 | ||
302 | void | |
303 | muntrace () | |
304 | { | |
305 | if (mallstream == NULL) | |
306 | return; | |
307 | ||
308 | fprintf (mallstream, "= End\n"); | |
309 | fclose (mallstream); | |
310 | mallstream = NULL; | |
311 | __free_hook = tr_old_free_hook; | |
312 | __malloc_hook = tr_old_malloc_hook; | |
313 | __realloc_hook = tr_old_realloc_hook; | |
314 | } |