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6d52618b | 1 | /* More debugging hooks for `malloc'. |
bfff8b1b | 2 | Copyright (C) 1991-2017 Free Software Foundation, Inc. |
41bdb6e2 | 3 | This file is part of the GNU C Library. |
6c8dbf00 OB |
4 | Written April 2, 1991 by John Gilmore of Cygnus Support. |
5 | Based on mcheck.c by Mike Haertel. | |
6d52618b | 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 | 17 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 PE |
18 | License along with the GNU C Library; if not, see |
19 | <http://www.gnu.org/licenses/>. */ | |
6d52618b | 20 | |
6c8dbf00 OB |
21 | #ifndef _MALLOC_INTERNAL |
22 | # define _MALLOC_INTERNAL | |
23 | # include <malloc.h> | |
24 | # include <mcheck.h> | |
ec999b8e | 25 | # include <libc-lock.h> |
6d52618b UD |
26 | #endif |
27 | ||
b3fc5f84 | 28 | #include <dlfcn.h> |
755104ed | 29 | #include <fcntl.h> |
6d52618b | 30 | #include <stdio.h> |
e03c3361 | 31 | #include <string.h> |
6d52618b | 32 | #include <stdlib.h> |
6d52618b | 33 | |
eb96ffb0 | 34 | #include <_itoa.h> |
d5cabaa4 | 35 | |
72112b0c | 36 | #include <libc-internal.h> |
825adeee | 37 | #include <dso_handle.h> |
66539a73 | 38 | |
72112b0c | 39 | #include <libio/iolibio.h> |
d18ea0c5 | 40 | #define setvbuf(s, b, f, l) _IO_setvbuf (s, b, f, l) |
72112b0c UD |
41 | #define fwrite(buf, size, count, fp) _IO_fwrite (buf, size, count, fp) |
42 | ||
43 | #include <kernel-features.h> | |
50304ef0 | 44 | |
e7993f20 UD |
45 | #define TRACE_BUFFER_SIZE 512 |
46 | ||
6d52618b | 47 | static FILE *mallstream; |
6c8dbf00 | 48 | static const char mallenv[] = "MALLOC_TRACE"; |
c877418f | 49 | static char *malloc_trace_buffer; |
6d52618b UD |
50 | |
51 | __libc_lock_define_initialized (static, lock); | |
52 | ||
53 | /* Address to breakpoint on accesses to... */ | |
f17a4233 | 54 | void *mallwatch; |
6d52618b | 55 | |
6d52618b | 56 | /* Old hook values. */ |
f17a4233 JM |
57 | static void (*tr_old_free_hook) (void *ptr, const void *); |
58 | static void *(*tr_old_malloc_hook) (size_t size, const void *); | |
59 | static void *(*tr_old_realloc_hook) (void *ptr, size_t size, | |
60 | const void *); | |
61 | static void *(*tr_old_memalign_hook) (size_t __alignment, size_t __size, | |
62 | const void *); | |
6d52618b UD |
63 | |
64 | /* This function is called when the block being alloc'd, realloc'd, or | |
65 | freed has an address matching the variable "mallwatch". In a debugger, | |
66 | set "mallwatch" to the address of interest, then put a breakpoint on | |
67 | tr_break. */ | |
68 | ||
79937577 | 69 | extern void tr_break (void) __THROW; |
ee2a5ae8 | 70 | libc_hidden_proto (tr_break) |
6d52618b | 71 | void |
60d2f8f3 | 72 | tr_break (void) |
6d52618b UD |
73 | { |
74 | } | |
ee2a5ae8 | 75 | libc_hidden_def (tr_break) |
6d52618b | 76 | |
0c71122c | 77 | static void |
f17a4233 | 78 | tr_where (const void *caller, Dl_info *info) |
6d52618b | 79 | { |
6ce75379 | 80 | if (caller != NULL) |
a2b08ee5 | 81 | { |
56e5eb46 | 82 | if (info != NULL) |
6c8dbf00 OB |
83 | { |
84 | char *buf = (char *) ""; | |
85 | if (info->dli_sname != NULL) | |
86 | { | |
87 | size_t len = strlen (info->dli_sname); | |
88 | buf = alloca (len + 6 + 2 * sizeof (void *)); | |
89 | ||
90 | buf[0] = '('; | |
f17a4233 JM |
91 | __stpcpy (_fitoa (caller >= (const void *) info->dli_saddr |
92 | ? caller - (const void *) info->dli_saddr | |
93 | : (const void *) info->dli_saddr - caller, | |
6c8dbf00 OB |
94 | __stpcpy (__mempcpy (buf + 1, info->dli_sname, |
95 | len), | |
f17a4233 | 96 | caller >= (void *) info->dli_saddr |
6c8dbf00 OB |
97 | ? "+0x" : "-0x"), |
98 | 16, 0), | |
99 | ")"); | |
100 | } | |
101 | ||
102 | fprintf (mallstream, "@ %s%s%s[%p] ", | |
103 | info->dli_fname ? : "", info->dli_fname ? ":" : "", | |
104 | buf, caller); | |
105 | } | |
a2b08ee5 | 106 | else |
6c8dbf00 | 107 | fprintf (mallstream, "@ [%p] ", caller); |
a2b08ee5 | 108 | } |
6d52618b UD |
109 | } |
110 | ||
56e5eb46 | 111 | static Dl_info * |
f17a4233 | 112 | lock_and_info (const void *caller, Dl_info *mem) |
56e5eb46 UD |
113 | { |
114 | if (caller == NULL) | |
115 | return NULL; | |
116 | ||
117 | Dl_info *res = _dl_addr (caller, mem, NULL, NULL) ? mem : NULL; | |
118 | ||
119 | __libc_lock_lock (lock); | |
120 | ||
121 | return res; | |
122 | } | |
123 | ||
c13a72b7 | 124 | static void |
f17a4233 | 125 | tr_freehook (void *ptr, const void *caller) |
6d52618b | 126 | { |
55465bd9 UD |
127 | if (ptr == NULL) |
128 | return; | |
56e5eb46 UD |
129 | |
130 | Dl_info mem; | |
131 | Dl_info *info = lock_and_info (caller, &mem); | |
132 | tr_where (caller, info); | |
a2b08ee5 UD |
133 | /* Be sure to print it first. */ |
134 | fprintf (mallstream, "- %p\n", ptr); | |
6d52618b | 135 | if (ptr == mallwatch) |
41043168 UD |
136 | { |
137 | __libc_lock_unlock (lock); | |
138 | tr_break (); | |
139 | __libc_lock_lock (lock); | |
140 | } | |
6d52618b | 141 | __free_hook = tr_old_free_hook; |
a2b08ee5 | 142 | if (tr_old_free_hook != NULL) |
6c8dbf00 | 143 | (*tr_old_free_hook)(ptr, caller); |
a2b08ee5 | 144 | else |
a334319f | 145 | free (ptr); |
6d52618b UD |
146 | __free_hook = tr_freehook; |
147 | __libc_lock_unlock (lock); | |
148 | } | |
149 | ||
f17a4233 JM |
150 | static void * |
151 | tr_mallochook (size_t size, const void *caller) | |
6d52618b | 152 | { |
f17a4233 | 153 | void *hdr; |
6d52618b | 154 | |
56e5eb46 UD |
155 | Dl_info mem; |
156 | Dl_info *info = lock_and_info (caller, &mem); | |
6d52618b UD |
157 | |
158 | __malloc_hook = tr_old_malloc_hook; | |
a2b08ee5 | 159 | if (tr_old_malloc_hook != NULL) |
f17a4233 | 160 | hdr = (void *) (*tr_old_malloc_hook)(size, caller); |
a2b08ee5 | 161 | else |
f17a4233 | 162 | hdr = (void *) malloc (size); |
6d52618b UD |
163 | __malloc_hook = tr_mallochook; |
164 | ||
56e5eb46 | 165 | tr_where (caller, info); |
6d52618b | 166 | /* We could be printing a NULL here; that's OK. */ |
c0fb8a56 | 167 | fprintf (mallstream, "+ %p %#lx\n", hdr, (unsigned long int) size); |
6d52618b | 168 | |
92e4472f UD |
169 | __libc_lock_unlock (lock); |
170 | ||
6d52618b UD |
171 | if (hdr == mallwatch) |
172 | tr_break (); | |
173 | ||
174 | return hdr; | |
175 | } | |
176 | ||
f17a4233 JM |
177 | static void * |
178 | tr_reallochook (void *ptr, size_t size, const void *caller) | |
6d52618b | 179 | { |
f17a4233 | 180 | void *hdr; |
6d52618b UD |
181 | |
182 | if (ptr == mallwatch) | |
183 | tr_break (); | |
184 | ||
56e5eb46 UD |
185 | Dl_info mem; |
186 | Dl_info *info = lock_and_info (caller, &mem); | |
6d52618b UD |
187 | |
188 | __free_hook = tr_old_free_hook; | |
189 | __malloc_hook = tr_old_malloc_hook; | |
190 | __realloc_hook = tr_old_realloc_hook; | |
a2b08ee5 | 191 | if (tr_old_realloc_hook != NULL) |
f17a4233 | 192 | hdr = (void *) (*tr_old_realloc_hook)(ptr, size, caller); |
a2b08ee5 | 193 | else |
f17a4233 | 194 | hdr = (void *) realloc (ptr, size); |
6d52618b UD |
195 | __free_hook = tr_freehook; |
196 | __malloc_hook = tr_mallochook; | |
197 | __realloc_hook = tr_reallochook; | |
198 | ||
56e5eb46 | 199 | tr_where (caller, info); |
6d52618b | 200 | if (hdr == NULL) |
2f5f40f4 AS |
201 | { |
202 | if (size != 0) | |
6c8dbf00 OB |
203 | /* Failed realloc. */ |
204 | fprintf (mallstream, "! %p %#lx\n", ptr, (unsigned long int) size); | |
2f5f40f4 | 205 | else |
6c8dbf00 | 206 | fprintf (mallstream, "- %p\n", ptr); |
2f5f40f4 | 207 | } |
6d52618b | 208 | else if (ptr == NULL) |
c0fb8a56 | 209 | fprintf (mallstream, "+ %p %#lx\n", hdr, (unsigned long int) size); |
6d52618b | 210 | else |
8261bc4b UD |
211 | { |
212 | fprintf (mallstream, "< %p\n", ptr); | |
56e5eb46 | 213 | tr_where (caller, info); |
8261bc4b UD |
214 | fprintf (mallstream, "> %p %#lx\n", hdr, (unsigned long int) size); |
215 | } | |
6d52618b | 216 | |
92e4472f UD |
217 | __libc_lock_unlock (lock); |
218 | ||
6d52618b UD |
219 | if (hdr == mallwatch) |
220 | tr_break (); | |
221 | ||
222 | return hdr; | |
223 | } | |
224 | ||
f17a4233 JM |
225 | static void * |
226 | tr_memalignhook (size_t alignment, size_t size, const void *caller) | |
e796f92f | 227 | { |
f17a4233 | 228 | void *hdr; |
e796f92f | 229 | |
56e5eb46 UD |
230 | Dl_info mem; |
231 | Dl_info *info = lock_and_info (caller, &mem); | |
e796f92f UD |
232 | |
233 | __memalign_hook = tr_old_memalign_hook; | |
234 | __malloc_hook = tr_old_malloc_hook; | |
235 | if (tr_old_memalign_hook != NULL) | |
f17a4233 | 236 | hdr = (void *) (*tr_old_memalign_hook)(alignment, size, caller); |
e796f92f | 237 | else |
f17a4233 | 238 | hdr = (void *) memalign (alignment, size); |
e796f92f UD |
239 | __memalign_hook = tr_memalignhook; |
240 | __malloc_hook = tr_mallochook; | |
241 | ||
56e5eb46 | 242 | tr_where (caller, info); |
e796f92f UD |
243 | /* We could be printing a NULL here; that's OK. */ |
244 | fprintf (mallstream, "+ %p %#lx\n", hdr, (unsigned long int) size); | |
245 | ||
246 | __libc_lock_unlock (lock); | |
247 | ||
248 | if (hdr == mallwatch) | |
249 | tr_break (); | |
250 | ||
251 | return hdr; | |
252 | } | |
253 | ||
254 | ||
a5a0310d | 255 | #ifdef _LIBC |
a5a0310d UD |
256 | |
257 | /* This function gets called to make sure all memory the library | |
258 | allocates get freed and so does not irritate the user when studying | |
259 | the mtrace output. */ | |
c877418f | 260 | static void __libc_freeres_fn_section |
a5a0310d UD |
261 | release_libc_mem (void) |
262 | { | |
263 | /* Only call the free function if we still are running in mtrace mode. */ | |
264 | if (mallstream != NULL) | |
265 | __libc_freeres (); | |
266 | } | |
267 | #endif | |
268 | ||
269 | ||
6d52618b UD |
270 | /* We enable tracing if either the environment variable MALLOC_TRACE |
271 | is set, or if the variable mallwatch has been patched to an address | |
272 | that the debugging user wants us to stop on. When patching mallwatch, | |
273 | don't forget to set a breakpoint on tr_break! */ | |
274 | ||
275 | void | |
60d2f8f3 | 276 | mtrace (void) |
6d52618b | 277 | { |
a5a0310d | 278 | #ifdef _LIBC |
c4563d2d | 279 | static int added_atexit_handler; |
a5a0310d | 280 | #endif |
6d52618b UD |
281 | char *mallfile; |
282 | ||
283 | /* Don't panic if we're called more than once. */ | |
284 | if (mallstream != NULL) | |
285 | return; | |
286 | ||
287 | #ifdef _LIBC | |
288 | /* When compiling the GNU libc we use the secure getenv function | |
289 | which prevents the misuse in case of SUID or SGID enabled | |
290 | programs. */ | |
84b3fd84 | 291 | mallfile = __libc_secure_getenv (mallenv); |
6d52618b UD |
292 | #else |
293 | mallfile = getenv (mallenv); | |
294 | #endif | |
295 | if (mallfile != NULL || mallwatch != NULL) | |
296 | { | |
c877418f RM |
297 | char *mtb = malloc (TRACE_BUFFER_SIZE); |
298 | if (mtb == NULL) | |
6c8dbf00 | 299 | return; |
c877418f | 300 | |
72112b0c | 301 | mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "wce"); |
6d52618b | 302 | if (mallstream != NULL) |
6c8dbf00 | 303 | { |
6c8dbf00 OB |
304 | /* Be sure it doesn't malloc its buffer! */ |
305 | malloc_trace_buffer = mtb; | |
306 | setvbuf (mallstream, malloc_trace_buffer, _IOFBF, TRACE_BUFFER_SIZE); | |
307 | fprintf (mallstream, "= Start\n"); | |
308 | tr_old_free_hook = __free_hook; | |
309 | __free_hook = tr_freehook; | |
310 | tr_old_malloc_hook = __malloc_hook; | |
311 | __malloc_hook = tr_mallochook; | |
312 | tr_old_realloc_hook = __realloc_hook; | |
313 | __realloc_hook = tr_reallochook; | |
314 | tr_old_memalign_hook = __memalign_hook; | |
315 | __memalign_hook = tr_memalignhook; | |
a5a0310d | 316 | #ifdef _LIBC |
6c8dbf00 OB |
317 | if (!added_atexit_handler) |
318 | { | |
6c8dbf00 OB |
319 | added_atexit_handler = 1; |
320 | __cxa_atexit ((void (*)(void *))release_libc_mem, NULL, | |
825adeee | 321 | __dso_handle); |
6c8dbf00 | 322 | } |
a5a0310d | 323 | #endif |
6c8dbf00 | 324 | } |
c877418f | 325 | else |
6c8dbf00 | 326 | free (mtb); |
6d52618b UD |
327 | } |
328 | } | |
329 | ||
330 | void | |
60d2f8f3 | 331 | muntrace (void) |
6d52618b UD |
332 | { |
333 | if (mallstream == NULL) | |
334 | return; | |
335 | ||
e19af380 PT |
336 | /* Do the reverse of what done in mtrace: first reset the hooks and |
337 | MALLSTREAM, and only after that write the trailer and close the | |
338 | file. */ | |
339 | FILE *f = mallstream; | |
6d52618b UD |
340 | mallstream = NULL; |
341 | __free_hook = tr_old_free_hook; | |
342 | __malloc_hook = tr_old_malloc_hook; | |
343 | __realloc_hook = tr_old_realloc_hook; | |
e796f92f | 344 | __memalign_hook = tr_old_memalign_hook; |
e19af380 PT |
345 | |
346 | fprintf (f, "= End\n"); | |
347 | fclose (f); | |
6d52618b | 348 | } |