1 /**************************************************************************
2 *
3 * Copyright 2008 VMware, Inc.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28 /**
29 * @file
30 * Memory debugging.
31 *
32 * @author José Fonseca <jfonseca@vmware.com>
33 */
34
35 #include "pipe/p_config.h"
36
37 #define DEBUG_MEMORY_IMPLEMENTATION
38
39 #include "os/os_thread.h"
40
41 #include "util/u_debug.h"
42 #include "util/u_debug_stack.h"
43 #include "util/list.h"
44 #include "util/os_memory.h"
45 #include "util/os_memory_debug.h"
46
47
48 #define DEBUG_MEMORY_MAGIC 0x6e34090aU
49 #define DEBUG_MEMORY_STACK 0 /* XXX: disabled until we have symbol lookup */
50
51 /**
52 * Set to 1 to enable checking of freed blocks of memory.
53 * Basically, don't really deallocate freed memory; keep it in the list
54 * but mark it as freed and do extra checking in debug_memory_check().
55 * This can detect some cases of use-after-free. But note that since we
56 * never really free anything this will use a lot of memory.
57 */
58 #define DEBUG_FREED_MEMORY 0
59 #define DEBUG_FREED_BYTE 0x33
60
61
62 struct debug_memory_header
63 {
64 struct list_head head;
65
66 unsigned long no;
67 const char *file;
68 unsigned line;
69 const char *function;
70 #if DEBUG_MEMORY_STACK
71 struct debug_stack_frame backtrace[DEBUG_MEMORY_STACK];
72 #endif
73 size_t size;
74 #if DEBUG_FREED_MEMORY
75 boolean freed; /**< Is this a freed block? */
76 #endif
77
78 unsigned magic;
79 unsigned tag;
80 };
81
82 struct debug_memory_footer
83 {
84 unsigned magic;
85 };
86
87
88 static struct list_head list = { &list, &list };
89
90 static mtx_t list_mutex = _MTX_INITIALIZER_NP;
91
92 static unsigned long last_no = 0;
93
94
95 static inline struct debug_memory_header *
header_from_data(void * data)96 header_from_data(void *data)
97 {
98 if (data)
99 return (struct debug_memory_header *)((char *)data - sizeof(struct debug_memory_header));
100 else
101 return NULL;
102 }
103
104 static inline void *
data_from_header(struct debug_memory_header * hdr)105 data_from_header(struct debug_memory_header *hdr)
106 {
107 if (hdr)
108 return (void *)((char *)hdr + sizeof(struct debug_memory_header));
109 else
110 return NULL;
111 }
112
113 static inline struct debug_memory_footer *
footer_from_header(struct debug_memory_header * hdr)114 footer_from_header(struct debug_memory_header *hdr)
115 {
116 if (hdr)
117 return (struct debug_memory_footer *)((char *)hdr + sizeof(struct debug_memory_header) + hdr->size);
118 else
119 return NULL;
120 }
121
122
123 void *
debug_malloc(const char * file,unsigned line,const char * function,size_t size)124 debug_malloc(const char *file, unsigned line, const char *function,
125 size_t size)
126 {
127 struct debug_memory_header *hdr;
128 struct debug_memory_footer *ftr;
129
130 hdr = os_malloc(sizeof(*hdr) + size + sizeof(*ftr));
131 if (!hdr) {
132 debug_printf("%s:%u:%s: out of memory when trying to allocate %lu bytes\n",
133 file, line, function,
134 (long unsigned)size);
135 return NULL;
136 }
137
138 hdr->no = last_no++;
139 hdr->file = file;
140 hdr->line = line;
141 hdr->function = function;
142 hdr->size = size;
143 hdr->magic = DEBUG_MEMORY_MAGIC;
144 hdr->tag = 0;
145 #if DEBUG_FREED_MEMORY
146 hdr->freed = FALSE;
147 #endif
148
149 #if DEBUG_MEMORY_STACK
150 debug_backtrace_capture(hdr->backtrace, 0, DEBUG_MEMORY_STACK);
151 #endif
152
153 ftr = footer_from_header(hdr);
154 ftr->magic = DEBUG_MEMORY_MAGIC;
155
156 mtx_lock(&list_mutex);
157 list_addtail(&hdr->head, &list);
158 mtx_unlock(&list_mutex);
159
160 return data_from_header(hdr);
161 }
162
163 void
debug_free(const char * file,unsigned line,const char * function,void * ptr)164 debug_free(const char *file, unsigned line, const char *function,
165 void *ptr)
166 {
167 struct debug_memory_header *hdr;
168 struct debug_memory_footer *ftr;
169
170 if (!ptr)
171 return;
172
173 hdr = header_from_data(ptr);
174 if (hdr->magic != DEBUG_MEMORY_MAGIC) {
175 debug_printf("%s:%u:%s: freeing bad or corrupted memory %p\n",
176 file, line, function,
177 ptr);
178 debug_assert(0);
179 return;
180 }
181
182 ftr = footer_from_header(hdr);
183 if (ftr->magic != DEBUG_MEMORY_MAGIC) {
184 debug_printf("%s:%u:%s: buffer overflow %p\n",
185 hdr->file, hdr->line, hdr->function,
186 ptr);
187 debug_assert(0);
188 }
189
190 #if DEBUG_FREED_MEMORY
191 /* Check for double-free */
192 assert(!hdr->freed);
193 /* Mark the block as freed but don't really free it */
194 hdr->freed = TRUE;
195 /* Save file/line where freed */
196 hdr->file = file;
197 hdr->line = line;
198 /* set freed memory to special value */
199 memset(ptr, DEBUG_FREED_BYTE, hdr->size);
200 #else
201 mtx_lock(&list_mutex);
202 list_del(&hdr->head);
203 mtx_unlock(&list_mutex);
204 hdr->magic = 0;
205 ftr->magic = 0;
206
207 os_free(hdr);
208 #endif
209 }
210
211 void *
debug_calloc(const char * file,unsigned line,const char * function,size_t count,size_t size)212 debug_calloc(const char *file, unsigned line, const char *function,
213 size_t count, size_t size )
214 {
215 void *ptr = debug_malloc( file, line, function, count * size );
216 if (ptr)
217 memset( ptr, 0, count * size );
218 return ptr;
219 }
220
221 void *
debug_realloc(const char * file,unsigned line,const char * function,void * old_ptr,size_t old_size,size_t new_size)222 debug_realloc(const char *file, unsigned line, const char *function,
223 void *old_ptr, size_t old_size, size_t new_size )
224 {
225 struct debug_memory_header *old_hdr, *new_hdr;
226 struct debug_memory_footer *old_ftr, *new_ftr;
227 void *new_ptr;
228
229 if (!old_ptr)
230 return debug_malloc( file, line, function, new_size );
231
232 if (!new_size) {
233 debug_free( file, line, function, old_ptr );
234 return NULL;
235 }
236
237 old_hdr = header_from_data(old_ptr);
238 if (old_hdr->magic != DEBUG_MEMORY_MAGIC) {
239 debug_printf("%s:%u:%s: reallocating bad or corrupted memory %p\n",
240 file, line, function,
241 old_ptr);
242 debug_assert(0);
243 return NULL;
244 }
245
246 old_ftr = footer_from_header(old_hdr);
247 if (old_ftr->magic != DEBUG_MEMORY_MAGIC) {
248 debug_printf("%s:%u:%s: buffer overflow %p\n",
249 old_hdr->file, old_hdr->line, old_hdr->function,
250 old_ptr);
251 debug_assert(0);
252 }
253
254 /* alloc new */
255 new_hdr = os_malloc(sizeof(*new_hdr) + new_size + sizeof(*new_ftr));
256 if (!new_hdr) {
257 debug_printf("%s:%u:%s: out of memory when trying to allocate %lu bytes\n",
258 file, line, function,
259 (long unsigned)new_size);
260 return NULL;
261 }
262 new_hdr->no = old_hdr->no;
263 new_hdr->file = old_hdr->file;
264 new_hdr->line = old_hdr->line;
265 new_hdr->function = old_hdr->function;
266 new_hdr->size = new_size;
267 new_hdr->magic = DEBUG_MEMORY_MAGIC;
268 new_hdr->tag = 0;
269 #if DEBUG_FREED_MEMORY
270 new_hdr->freed = FALSE;
271 #endif
272
273 new_ftr = footer_from_header(new_hdr);
274 new_ftr->magic = DEBUG_MEMORY_MAGIC;
275
276 mtx_lock(&list_mutex);
277 list_replace(&old_hdr->head, &new_hdr->head);
278 mtx_unlock(&list_mutex);
279
280 /* copy data */
281 new_ptr = data_from_header(new_hdr);
282 memcpy( new_ptr, old_ptr, old_size < new_size ? old_size : new_size );
283
284 /* free old */
285 old_hdr->magic = 0;
286 old_ftr->magic = 0;
287 os_free(old_hdr);
288
289 return new_ptr;
290 }
291
292 unsigned long
debug_memory_begin(void)293 debug_memory_begin(void)
294 {
295 return last_no;
296 }
297
298 void
debug_memory_end(unsigned long start_no)299 debug_memory_end(unsigned long start_no)
300 {
301 size_t total_size = 0;
302 struct list_head *entry;
303
304 if (start_no == last_no)
305 return;
306
307 entry = list.prev;
308 for (; entry != &list; entry = entry->prev) {
309 struct debug_memory_header *hdr;
310 void *ptr;
311 struct debug_memory_footer *ftr;
312
313 hdr = LIST_ENTRY(struct debug_memory_header, entry, head);
314 ptr = data_from_header(hdr);
315 ftr = footer_from_header(hdr);
316
317 if (hdr->magic != DEBUG_MEMORY_MAGIC) {
318 debug_printf("%s:%u:%s: bad or corrupted memory %p\n",
319 hdr->file, hdr->line, hdr->function,
320 ptr);
321 debug_assert(0);
322 }
323
324 if ((start_no <= hdr->no && hdr->no < last_no) ||
325 (last_no < start_no && (hdr->no < last_no || start_no <= hdr->no))) {
326 debug_printf("%s:%u:%s: %lu bytes at %p not freed\n",
327 hdr->file, hdr->line, hdr->function,
328 (unsigned long) hdr->size, ptr);
329 #if DEBUG_MEMORY_STACK
330 debug_backtrace_dump(hdr->backtrace, DEBUG_MEMORY_STACK);
331 #endif
332 total_size += hdr->size;
333 }
334
335 if (ftr->magic != DEBUG_MEMORY_MAGIC) {
336 debug_printf("%s:%u:%s: buffer overflow %p\n",
337 hdr->file, hdr->line, hdr->function,
338 ptr);
339 debug_assert(0);
340 }
341 }
342
343 if (total_size) {
344 debug_printf("Total of %lu KB of system memory apparently leaked\n",
345 (unsigned long) (total_size + 1023)/1024);
346 }
347 else {
348 debug_printf("No memory leaks detected.\n");
349 }
350 }
351
352
353 /**
354 * Put a tag (arbitrary integer) on a memory block.
355 * Can be useful for debugging.
356 */
357 void
debug_memory_tag(void * ptr,unsigned tag)358 debug_memory_tag(void *ptr, unsigned tag)
359 {
360 struct debug_memory_header *hdr;
361
362 if (!ptr)
363 return;
364
365 hdr = header_from_data(ptr);
366 if (hdr->magic != DEBUG_MEMORY_MAGIC) {
367 debug_printf("%s corrupted memory at %p\n", __FUNCTION__, ptr);
368 debug_assert(0);
369 }
370
371 hdr->tag = tag;
372 }
373
374
375 /**
376 * Check the given block of memory for validity/corruption.
377 */
378 void
debug_memory_check_block(void * ptr)379 debug_memory_check_block(void *ptr)
380 {
381 struct debug_memory_header *hdr;
382 struct debug_memory_footer *ftr;
383
384 if (!ptr)
385 return;
386
387 hdr = header_from_data(ptr);
388 ftr = footer_from_header(hdr);
389
390 if (hdr->magic != DEBUG_MEMORY_MAGIC) {
391 debug_printf("%s:%u:%s: bad or corrupted memory %p\n",
392 hdr->file, hdr->line, hdr->function, ptr);
393 debug_assert(0);
394 }
395
396 if (ftr->magic != DEBUG_MEMORY_MAGIC) {
397 debug_printf("%s:%u:%s: buffer overflow %p\n",
398 hdr->file, hdr->line, hdr->function, ptr);
399 debug_assert(0);
400 }
401 }
402
403
404
405 /**
406 * We can periodically call this from elsewhere to do a basic sanity
407 * check of the heap memory we've allocated.
408 */
409 void
debug_memory_check(void)410 debug_memory_check(void)
411 {
412 struct list_head *entry;
413
414 entry = list.prev;
415 for (; entry != &list; entry = entry->prev) {
416 struct debug_memory_header *hdr;
417 struct debug_memory_footer *ftr;
418 const char *ptr;
419
420 hdr = LIST_ENTRY(struct debug_memory_header, entry, head);
421 ftr = footer_from_header(hdr);
422 ptr = (const char *) data_from_header(hdr);
423
424 if (hdr->magic != DEBUG_MEMORY_MAGIC) {
425 debug_printf("%s:%u:%s: bad or corrupted memory %p\n",
426 hdr->file, hdr->line, hdr->function, ptr);
427 debug_assert(0);
428 }
429
430 if (ftr->magic != DEBUG_MEMORY_MAGIC) {
431 debug_printf("%s:%u:%s: buffer overflow %p\n",
432 hdr->file, hdr->line, hdr->function, ptr);
433 debug_assert(0);
434 }
435
436 #if DEBUG_FREED_MEMORY
437 /* If this block is marked as freed, check that it hasn't been touched */
438 if (hdr->freed) {
439 int i;
440 for (i = 0; i < hdr->size; i++) {
441 if (ptr[i] != DEBUG_FREED_BYTE) {
442 debug_printf("Memory error: byte %d of block at %p of size %d is 0x%x\n",
443 i, ptr, hdr->size, ptr[i]);
444 debug_printf("Block was freed at %s:%d\n", hdr->file, hdr->line);
445 }
446 assert(ptr[i] == DEBUG_FREED_BYTE);
447 }
448 }
449 #endif
450 }
451 }
452