src/util/u_debug_memory.c

   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 *
  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 *
 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 *
 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 *
 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
 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 *
 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 *
 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
 293 debug_memory_begin(void)
 294 {
 295    return last_no;
 296 }
 297
 298 void
 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
 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
 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
 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 }