crypto/mem_dbg.c

   1 /*
   2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <time.h>
  13 #include "internal/cryptlib.h"
  14 #include <openssl/crypto.h>
  15 #include <openssl/buffer.h>
  16 #include "internal/bio.h"
  17 #include <openssl/lhash.h>
  18
  19 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
  20 # include <execinfo.h>
  21 #endif
  22
  23 /*
  24  * The state changes to CRYPTO_MEM_CHECK_ON | CRYPTO_MEM_CHECK_ENABLE when
  25  * the application asks for it (usually after library initialisation for
  26  * which no book-keeping is desired). State CRYPTO_MEM_CHECK_ON exists only
  27  * temporarily when the library thinks that certain allocations should not be
  28  * checked (e.g. the data structures used for memory checking).  It is not
  29  * suitable as an initial state: the library will unexpectedly enable memory
  30  * checking when it executes one of those sections that want to disable
  31  * checking temporarily. State CRYPTO_MEM_CHECK_ENABLE without ..._ON makes
  32  * no sense whatsoever.
  33  */
  34 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
  35 static int mh_mode = CRYPTO_MEM_CHECK_OFF;
  36 #endif
  37
  38 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
  39 static unsigned long order = 0; /* number of memory requests */
  40
  41 /*-
  42  * For application-defined information (static C-string `info')
  43  * to be displayed in memory leak list.
  44  * Each thread has its own stack.  For applications, there is
  45  *   OPENSSL_mem_debug_push("...")     to push an entry,
  46  *   OPENSSL_mem_debug_pop()     to pop an entry,
  47  */
  48 struct app_mem_info_st {
  49     CRYPTO_THREAD_ID threadid;
  50     const char *file;
  51     int line;
  52     const char *info;
  53     struct app_mem_info_st *next; /* tail of thread's stack */
  54     int references;
  55 };
  56
  57 static CRYPTO_ONCE memdbg_init = CRYPTO_ONCE_STATIC_INIT;
  58 static CRYPTO_RWLOCK *malloc_lock = NULL;
  59 static CRYPTO_RWLOCK *long_malloc_lock = NULL;
  60 static CRYPTO_THREAD_LOCAL appinfokey;
  61
  62 /* memory-block description */
  63 struct mem_st {
  64     void *addr;
  65     int num;
  66     const char *file;
  67     int line;
  68     CRYPTO_THREAD_ID threadid;
  69     unsigned long order;
  70     time_t time;
  71     APP_INFO *app_info;
  72 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
  73     void *array[30];
  74     size_t array_siz;
  75 #endif
  76 };
  77
  78 static LHASH_OF(MEM) *mh = NULL; /* hash-table of memory requests (address as
  79                                   * key); access requires MALLOC2 lock */
  80
  81 /* num_disable > 0 iff mh_mode == CRYPTO_MEM_CHECK_ON (w/o ..._ENABLE) */
  82 static unsigned int num_disable = 0;
  83
  84 /*
  85  * Valid iff num_disable > 0.  long_malloc_lock is locked exactly in this
  86  * case (by the thread named in disabling_thread).
  87  */
  88 static CRYPTO_THREAD_ID disabling_threadid;
  89
  90 static void do_memdbg_init(void)
  91 {
  92     malloc_lock = CRYPTO_THREAD_lock_new();
  93     long_malloc_lock = CRYPTO_THREAD_lock_new();
  94     CRYPTO_THREAD_init_local(&appinfokey, NULL);
  95 }
  96
  97 static void app_info_free(APP_INFO *inf)
  98 {
  99     if (!inf)
 100         return;
 101     if (--(inf->references) <= 0) {
 102         app_info_free(inf->next);
 103         OPENSSL_free(inf);
 104     }
 105 }
 106 #endif
 107
 108 int CRYPTO_mem_ctrl(int mode)
 109 {
 110 #ifdef OPENSSL_NO_CRYPTO_MDEBUG
 111     return mode - mode;
 112 #else
 113     int ret = mh_mode;
 114
 115     CRYPTO_THREAD_run_once(&memdbg_init, do_memdbg_init);
 116
 117     CRYPTO_THREAD_write_lock(malloc_lock);
 118     switch (mode) {
 119     default:
 120         break;
 121
 122     case CRYPTO_MEM_CHECK_ON:
 123         mh_mode = CRYPTO_MEM_CHECK_ON | CRYPTO_MEM_CHECK_ENABLE;
 124         num_disable = 0;
 125         break;
 126
 127     case CRYPTO_MEM_CHECK_OFF:
 128         mh_mode = 0;
 129         num_disable = 0;
 130         break;
 131
 132     /* switch off temporarily (for library-internal use): */
 133     case CRYPTO_MEM_CHECK_DISABLE:
 134         if (mh_mode & CRYPTO_MEM_CHECK_ON) {
 135             CRYPTO_THREAD_ID cur = CRYPTO_THREAD_get_current_id();
 136             /* see if we don't have long_malloc_lock already */
 137             if (!num_disable
 138                 || !CRYPTO_THREAD_compare_id(disabling_threadid, cur)) {
 139                 /*
 140                  * Long-time lock long_malloc_lock must not be claimed
 141                  * while we're holding malloc_lock, or we'll deadlock
 142                  * if somebody else holds long_malloc_lock (and cannot
 143                  * release it because we block entry to this function). Give
 144                  * them a chance, first, and then claim the locks in
 145                  * appropriate order (long-time lock first).
 146                  */
 147                 CRYPTO_THREAD_unlock(malloc_lock);
 148                 /*
 149                  * Note that after we have waited for long_malloc_lock and
 150                  * malloc_lock, we'll still be in the right "case" and
 151                  * "if" branch because MemCheck_start and MemCheck_stop may
 152                  * never be used while there are multiple OpenSSL threads.
 153                  */
 154                 CRYPTO_THREAD_write_lock(long_malloc_lock);
 155                 CRYPTO_THREAD_write_lock(malloc_lock);
 156                 mh_mode &= ~CRYPTO_MEM_CHECK_ENABLE;
 157                 disabling_threadid = cur;
 158             }
 159             num_disable++;
 160         }
 161         break;
 162
 163     case CRYPTO_MEM_CHECK_ENABLE:
 164         if (mh_mode & CRYPTO_MEM_CHECK_ON) {
 165             if (num_disable) {  /* always true, or something is going wrong */
 166                 num_disable--;
 167                 if (num_disable == 0) {
 168                     mh_mode |= CRYPTO_MEM_CHECK_ENABLE;
 169                     CRYPTO_THREAD_unlock(long_malloc_lock);
 170                 }
 171             }
 172         }
 173         break;
 174     }
 175     CRYPTO_THREAD_unlock(malloc_lock);
 176     return (ret);
 177 #endif
 178 }
 179
 180 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
 181
 182 static int mem_check_on(void)
 183 {
 184     int ret = 0;
 185     CRYPTO_THREAD_ID cur;
 186
 187     if (mh_mode & CRYPTO_MEM_CHECK_ON) {
 188         CRYPTO_THREAD_run_once(&memdbg_init, do_memdbg_init);
 189
 190         cur = CRYPTO_THREAD_get_current_id();
 191         CRYPTO_THREAD_read_lock(malloc_lock);
 192
 193         ret = (mh_mode & CRYPTO_MEM_CHECK_ENABLE)
 194             || !CRYPTO_THREAD_compare_id(disabling_threadid, cur);
 195
 196         CRYPTO_THREAD_unlock(malloc_lock);
 197     }
 198     return (ret);
 199 }
 200
 201 static int mem_cmp(const MEM *a, const MEM *b)
 202 {
 203 #ifdef _WIN64
 204     const char *ap = (const char *)a->addr, *bp = (const char *)b->addr;
 205     if (ap == bp)
 206         return 0;
 207     else if (ap > bp)
 208         return 1;
 209     else
 210         return -1;
 211 #else
 212     return (const char *)a->addr - (const char *)b->addr;
 213 #endif
 214 }
 215
 216 static unsigned long mem_hash(const MEM *a)
 217 {
 218     size_t ret;
 219
 220     ret = (size_t)a->addr;
 221
 222     ret = ret * 17851 + (ret >> 14) * 7 + (ret >> 4) * 251;
 223     return (ret);
 224 }
 225
 226 /* returns 1 if there was an info to pop, 0 if the stack was empty. */
 227 static int pop_info(void)
 228 {
 229     APP_INFO *current = NULL;
 230
 231     CRYPTO_THREAD_run_once(&memdbg_init, do_memdbg_init);
 232     current = (APP_INFO *)CRYPTO_THREAD_get_local(&appinfokey);
 233     if (current != NULL) {
 234         APP_INFO *next = current->next;
 235
 236         if (next != NULL) {
 237             next->references++;
 238             CRYPTO_THREAD_set_local(&appinfokey, next);
 239         } else {
 240             CRYPTO_THREAD_set_local(&appinfokey, NULL);
 241         }
 242         if (--(current->references) <= 0) {
 243             current->next = NULL;
 244             if (next != NULL)
 245                 next->references--;
 246             OPENSSL_free(current);
 247         }
 248         return 1;
 249     }
 250     return 0;
 251 }
 252
 253 int CRYPTO_mem_debug_push(const char *info, const char *file, int line)
 254 {
 255     APP_INFO *ami, *amim;
 256     int ret = 0;
 257
 258     if (mem_check_on()) {
 259         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 260
 261         CRYPTO_THREAD_run_once(&memdbg_init, do_memdbg_init);
 262
 263         if ((ami = OPENSSL_malloc(sizeof(*ami))) == NULL)
 264             goto err;
 265
 266         ami->threadid = CRYPTO_THREAD_get_current_id();
 267         ami->file = file;
 268         ami->line = line;
 269         ami->info = info;
 270         ami->references = 1;
 271         ami->next = NULL;
 272
 273         amim = (APP_INFO *)CRYPTO_THREAD_get_local(&appinfokey);
 274         CRYPTO_THREAD_set_local(&appinfokey, ami);
 275
 276         if (amim != NULL)
 277             ami->next = amim;
 278         ret = 1;
 279  err:
 280         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 281     }
 282
 283     return (ret);
 284 }
 285
 286 int CRYPTO_mem_debug_pop(void)
 287 {
 288     int ret = 0;
 289
 290     if (mem_check_on()) {
 291         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 292         ret = pop_info();
 293         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 294     }
 295     return (ret);
 296 }
 297
 298 static unsigned long break_order_num = 0;
 299
 300 void CRYPTO_mem_debug_malloc(void *addr, size_t num, int before_p,
 301                              const char *file, int line)
 302 {
 303     MEM *m, *mm;
 304     APP_INFO *amim;
 305
 306     switch (before_p & 127) {
 307     case 0:
 308         break;
 309     case 1:
 310         if (addr == NULL)
 311             break;
 312
 313         if (mem_check_on()) {
 314             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 315
 316             CRYPTO_THREAD_run_once(&memdbg_init, do_memdbg_init);
 317
 318             if ((m = OPENSSL_malloc(sizeof(*m))) == NULL) {
 319                 OPENSSL_free(addr);
 320                 CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 321                 return;
 322             }
 323             if (mh == NULL) {
 324                 if ((mh = lh_MEM_new(mem_hash, mem_cmp)) == NULL) {
 325                     OPENSSL_free(addr);
 326                     OPENSSL_free(m);
 327                     addr = NULL;
 328                     goto err;
 329                 }
 330             }
 331
 332             m->addr = addr;
 333             m->file = file;
 334             m->line = line;
 335             m->num = num;
 336             m->threadid = CRYPTO_THREAD_get_current_id();
 337
 338             if (order == break_order_num) {
 339                 /* BREAK HERE */
 340                 m->order = order;
 341             }
 342             m->order = order++;
 343 # ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
 344             m->array_siz = backtrace(m->array, OSSL_NELEM(m->array));
 345 # endif
 346             m->time = time(NULL);
 347
 348             amim = (APP_INFO *)CRYPTO_THREAD_get_local(&appinfokey);
 349             m->app_info = amim;
 350             if (amim != NULL)
 351                 amim->references++;
 352
 353             if ((mm = lh_MEM_insert(mh, m)) != NULL) {
 354                 /* Not good, but don't sweat it */
 355                 if (mm->app_info != NULL) {
 356                     mm->app_info->references--;
 357                 }
 358                 OPENSSL_free(mm);
 359             }
 360  err:
 361             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 362         }
 363         break;
 364     }
 365     return;
 366 }
 367
 368 void CRYPTO_mem_debug_free(void *addr, int before_p,
 369         const char *file, int line)
 370 {
 371     MEM m, *mp;
 372
 373     switch (before_p) {
 374     case 0:
 375         if (addr == NULL)
 376             break;
 377
 378         if (mem_check_on() && (mh != NULL)) {
 379             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 380
 381             m.addr = addr;
 382             mp = lh_MEM_delete(mh, &m);
 383             if (mp != NULL) {
 384                 app_info_free(mp->app_info);
 385                 OPENSSL_free(mp);
 386             }
 387
 388             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 389         }
 390         break;
 391     case 1:
 392         break;
 393     }
 394 }
 395
 396 void CRYPTO_mem_debug_realloc(void *addr1, void *addr2, size_t num,
 397                               int before_p, const char *file, int line)
 398 {
 399     MEM m, *mp;
 400
 401     switch (before_p) {
 402     case 0:
 403         break;
 404     case 1:
 405         if (addr2 == NULL)
 406             break;
 407
 408         if (addr1 == NULL) {
 409             CRYPTO_mem_debug_malloc(addr2, num, 128 | before_p, file, line);
 410             break;
 411         }
 412
 413         if (mem_check_on()) {
 414             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 415
 416             m.addr = addr1;
 417             mp = lh_MEM_delete(mh, &m);
 418             if (mp != NULL) {
 419                 mp->addr = addr2;
 420                 mp->num = num;
 421 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
 422                 mp->array_siz = backtrace(mp->array, OSSL_NELEM(mp->array));
 423 #endif
 424                 (void)lh_MEM_insert(mh, mp);
 425             }
 426
 427             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 428         }
 429         break;
 430     }
 431     return;
 432 }
 433
 434 typedef struct mem_leak_st {
 435     BIO *bio;
 436     int chunks;
 437     long bytes;
 438 } MEM_LEAK;
 439
 440 static void print_leak(const MEM *m, MEM_LEAK *l)
 441 {
 442     char buf[1024];
 443     char *bufp = buf;
 444     APP_INFO *amip;
 445     int ami_cnt;
 446     struct tm *lcl = NULL;
 447     /*
 448      * Convert between CRYPTO_THREAD_ID (which could be anything at all) and
 449      * a long. This may not be meaningful depending on what CRYPTO_THREAD_ID is
 450      * but hopefully should give something sensible on most platforms
 451      */
 452     union {
 453         CRYPTO_THREAD_ID tid;
 454         unsigned long ltid;
 455     } tid;
 456     CRYPTO_THREAD_ID ti;
 457
 458 #define BUF_REMAIN (sizeof buf - (size_t)(bufp - buf))
 459
 460     lcl = localtime(&m->time);
 461     BIO_snprintf(bufp, BUF_REMAIN, "[%02d:%02d:%02d] ",
 462                  lcl->tm_hour, lcl->tm_min, lcl->tm_sec);
 463     bufp += strlen(bufp);
 464
 465     BIO_snprintf(bufp, BUF_REMAIN, "%5lu file=%s, line=%d, ",
 466                  m->order, m->file, m->line);
 467     bufp += strlen(bufp);
 468
 469     tid.ltid = 0;
 470     tid.tid = m->threadid;
 471     BIO_snprintf(bufp, BUF_REMAIN, "thread=%lu, ", tid.ltid);
 472     bufp += strlen(bufp);
 473
 474     BIO_snprintf(bufp, BUF_REMAIN, "number=%d, address=%p\n",
 475                  m->num, m->addr);
 476     bufp += strlen(bufp);
 477
 478     BIO_puts(l->bio, buf);
 479
 480     l->chunks++;
 481     l->bytes += m->num;
 482
 483     amip = m->app_info;
 484     ami_cnt = 0;
 485
 486     if (amip) {
 487         ti = amip->threadid;
 488
 489         do {
 490             int buf_len;
 491             int info_len;
 492
 493             ami_cnt++;
 494             memset(buf, '>', ami_cnt);
 495             tid.ltid = 0;
 496             tid.tid = amip->threadid;
 497             BIO_snprintf(buf + ami_cnt, sizeof buf - ami_cnt,
 498                          " thread=%lu, file=%s, line=%d, info=\"",
 499                          tid.ltid, amip->file,
 500                          amip->line);
 501             buf_len = strlen(buf);
 502             info_len = strlen(amip->info);
 503             if (128 - buf_len - 3 < info_len) {
 504                 memcpy(buf + buf_len, amip->info, 128 - buf_len - 3);
 505                 buf_len = 128 - 3;
 506             } else {
 507                 OPENSSL_strlcpy(buf + buf_len, amip->info, sizeof buf - buf_len);
 508                 buf_len = strlen(buf);
 509             }
 510             BIO_snprintf(buf + buf_len, sizeof buf - buf_len, "\"\n");
 511
 512             BIO_puts(l->bio, buf);
 513
 514             amip = amip->next;
 515         }
 516         while (amip && CRYPTO_THREAD_compare_id(amip->threadid, ti));
 517     }
 518
 519 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
 520     {
 521         size_t i;
 522         char **strings = backtrace_symbols(m->array, m->array_siz);
 523
 524         for (i = 0; i < m->array_siz; i++)
 525             fprintf(stderr, "##> %s\n", strings[i]);
 526         free(strings);
 527     }
 528 #endif
 529 }
 530
 531 IMPLEMENT_LHASH_DOALL_ARG_CONST(MEM, MEM_LEAK);
 532
 533 int CRYPTO_mem_leaks(BIO *b)
 534 {
 535     MEM_LEAK ml;
 536
 537     /*
 538      * OPENSSL_cleanup() will free the ex_data locks so we can't have any
 539      * ex_data hanging around
 540      */
 541     bio_free_ex_data(b);
 542
 543     /* Ensure all resources are released */
 544     OPENSSL_cleanup();
 545
 546     CRYPTO_THREAD_run_once(&memdbg_init, do_memdbg_init);
 547
 548     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 549
 550     ml.bio = b;
 551     ml.bytes = 0;
 552     ml.chunks = 0;
 553     if (mh != NULL)
 554         lh_MEM_doall_MEM_LEAK(mh, print_leak, &ml);
 555
 556     if (ml.chunks != 0) {
 557         BIO_printf(b, "%ld bytes leaked in %d chunks\n", ml.bytes, ml.chunks);
 558     } else {
 559         /*
 560          * Make sure that, if we found no leaks, memory-leak debugging itself
 561          * does not introduce memory leaks (which might irritate external
 562          * debugging tools). (When someone enables leak checking, but does not
 563          * call this function, we declare it to be their fault.)
 564          */
 565         int old_mh_mode;
 566
 567         CRYPTO_THREAD_write_lock(malloc_lock);
 568
 569         /*
 570          * avoid deadlock when lh_free() uses CRYPTO_mem_debug_free(), which uses
 571          * mem_check_on
 572          */
 573         old_mh_mode = mh_mode;
 574         mh_mode = CRYPTO_MEM_CHECK_OFF;
 575
 576         lh_MEM_free(mh);
 577         mh = NULL;
 578
 579         mh_mode = old_mh_mode;
 580         CRYPTO_THREAD_unlock(malloc_lock);
 581     }
 582     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_OFF);
 583
 584     /* Clean up locks etc */
 585     CRYPTO_THREAD_cleanup_local(&appinfokey);
 586     CRYPTO_THREAD_lock_free(malloc_lock);
 587     CRYPTO_THREAD_lock_free(long_malloc_lock);
 588     malloc_lock = NULL;
 589     long_malloc_lock = NULL;
 590
 591     return ml.chunks == 0 ? 1 : 0;
 592 }
 593
 594 # ifndef OPENSSL_NO_STDIO
 595 int CRYPTO_mem_leaks_fp(FILE *fp)
 596 {
 597     BIO *b;
 598     int ret;
 599
 600     /*
 601      * Need to turn off memory checking when allocated BIOs ... especially as
 602      * we're creating them at a time when we're trying to check we've not
 603      * left anything un-free()'d!!
 604      */
 605     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 606     b = BIO_new(BIO_s_file());
 607     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 608     if (b == NULL)
 609         return -1;
 610     BIO_set_fp(b, fp, BIO_NOCLOSE);
 611     ret = CRYPTO_mem_leaks(b);
 612     BIO_free(b);
 613     return ret;
 614 }
 615 # endif
 616
 617 #endif