crypto/mem_dbg.c

   1 /*
   2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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 "internal/thread_once.h"
  15 #include <openssl/crypto.h>
  16 #include <openssl/buffer.h>
  17 #include "internal/bio.h"
  18 #include <openssl/lhash.h>
  19
  20 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
  21 # include <execinfo.h>
  22 #endif
  23
  24 /*
  25  * The state changes to CRYPTO_MEM_CHECK_ON | CRYPTO_MEM_CHECK_ENABLE when
  26  * the application asks for it (usually after library initialisation for
  27  * which no book-keeping is desired). State CRYPTO_MEM_CHECK_ON exists only
  28  * temporarily when the library thinks that certain allocations should not be
  29  * checked (e.g. the data structures used for memory checking).  It is not
  30  * suitable as an initial state: the library will unexpectedly enable memory
  31  * checking when it executes one of those sections that want to disable
  32  * checking temporarily. State CRYPTO_MEM_CHECK_ENABLE without ..._ON makes
  33  * no sense whatsoever.
  34  */
  35 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
  36 static int mh_mode = CRYPTO_MEM_CHECK_OFF;
  37 #endif
  38
  39 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
  40 static unsigned long order = 0; /* number of memory requests */
  41
  42 /*-
  43  * For application-defined information (static C-string `info')
  44  * to be displayed in memory leak list.
  45  * Each thread has its own stack.  For applications, there is
  46  *   OPENSSL_mem_debug_push("...")     to push an entry,
  47  *   OPENSSL_mem_debug_pop()     to pop an entry,
  48  */
  49 struct app_mem_info_st {
  50     CRYPTO_THREAD_ID threadid;
  51     const char *file;
  52     int line;
  53     const char *info;
  54     struct app_mem_info_st *next; /* tail of thread's stack */
  55     int references;
  56 };
  57
  58 static CRYPTO_ONCE memdbg_init = CRYPTO_ONCE_STATIC_INIT;
  59 CRYPTO_RWLOCK *memdbg_lock;
  60 static CRYPTO_RWLOCK *long_memdbg_lock;
  61 static CRYPTO_THREAD_LOCAL appinfokey;
  62
  63 /* memory-block description */
  64 struct mem_st {
  65     void *addr;
  66     int num;
  67     const char *file;
  68     int line;
  69     CRYPTO_THREAD_ID threadid;
  70     unsigned long order;
  71     time_t time;
  72     APP_INFO *app_info;
  73 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
  74     void *array[30];
  75     size_t array_siz;
  76 #endif
  77 };
  78
  79 /*
  80  * hash-table of memory requests (address as * key); access requires
  81  * long_memdbg_lock lock
  82  */
  83 static LHASH_OF(MEM) *mh = NULL;
  84
  85 /* num_disable > 0 iff mh_mode == CRYPTO_MEM_CHECK_ON (w/o ..._ENABLE) */
  86 static unsigned int num_disable = 0;
  87
  88 /*
  89  * Valid iff num_disable > 0.  long_memdbg_lock is locked exactly in this
  90  * case (by the thread named in disabling_thread).
  91  */
  92 static CRYPTO_THREAD_ID disabling_threadid;
  93
  94 DEFINE_RUN_ONCE_STATIC(do_memdbg_init)
  95 {
  96     memdbg_lock = CRYPTO_THREAD_lock_new();
  97     long_memdbg_lock = CRYPTO_THREAD_lock_new();
  98     if (memdbg_lock == NULL || long_memdbg_lock == NULL
  99         || !CRYPTO_THREAD_init_local(&appinfokey, NULL)) {
 100         CRYPTO_THREAD_lock_free(memdbg_lock);
 101         memdbg_lock = NULL;
 102         CRYPTO_THREAD_lock_free(long_memdbg_lock);
 103         long_memdbg_lock = NULL;
 104         return 0;
 105     }
 106     return 1;
 107 }
 108
 109 static void app_info_free(APP_INFO *inf)
 110 {
 111     if (inf == NULL)
 112         return;
 113     if (--(inf->references) <= 0) {
 114         app_info_free(inf->next);
 115         OPENSSL_free(inf);
 116     }
 117 }
 118 #endif
 119
 120 int CRYPTO_mem_ctrl(int mode)
 121 {
 122 #ifdef OPENSSL_NO_CRYPTO_MDEBUG
 123     return mode - mode;
 124 #else
 125     int ret = mh_mode;
 126
 127     if (!RUN_ONCE(&memdbg_init, do_memdbg_init))
 128         return -1;
 129
 130     CRYPTO_THREAD_write_lock(memdbg_lock);
 131     switch (mode) {
 132     default:
 133         break;
 134
 135     case CRYPTO_MEM_CHECK_ON:
 136         mh_mode = CRYPTO_MEM_CHECK_ON | CRYPTO_MEM_CHECK_ENABLE;
 137         num_disable = 0;
 138         break;
 139
 140     case CRYPTO_MEM_CHECK_OFF:
 141         mh_mode = 0;
 142         num_disable = 0;
 143         break;
 144
 145     /* switch off temporarily (for library-internal use): */
 146     case CRYPTO_MEM_CHECK_DISABLE:
 147         if (mh_mode & CRYPTO_MEM_CHECK_ON) {
 148             CRYPTO_THREAD_ID cur = CRYPTO_THREAD_get_current_id();
 149             /* see if we don't have long_memdbg_lock already */
 150             if (!num_disable
 151                 || !CRYPTO_THREAD_compare_id(disabling_threadid, cur)) {
 152                 /*
 153                  * Long-time lock long_memdbg_lock must not be claimed
 154                  * while we're holding memdbg_lock, or we'll deadlock
 155                  * if somebody else holds long_memdbg_lock (and cannot
 156                  * release it because we block entry to this function). Give
 157                  * them a chance, first, and then claim the locks in
 158                  * appropriate order (long-time lock first).
 159                  */
 160                 CRYPTO_THREAD_unlock(memdbg_lock);
 161                 /*
 162                  * Note that after we have waited for long_memdbg_lock and
 163                  * memdbg_lock, we'll still be in the right "case" and
 164                  * "if" branch because MemCheck_start and MemCheck_stop may
 165                  * never be used while there are multiple OpenSSL threads.
 166                  */
 167                 CRYPTO_THREAD_write_lock(long_memdbg_lock);
 168                 CRYPTO_THREAD_write_lock(memdbg_lock);
 169                 mh_mode &= ~CRYPTO_MEM_CHECK_ENABLE;
 170                 disabling_threadid = cur;
 171             }
 172             num_disable++;
 173         }
 174         break;
 175
 176     case CRYPTO_MEM_CHECK_ENABLE:
 177         if (mh_mode & CRYPTO_MEM_CHECK_ON) {
 178             if (num_disable) {  /* always true, or something is going wrong */
 179                 num_disable--;
 180                 if (num_disable == 0) {
 181                     mh_mode |= CRYPTO_MEM_CHECK_ENABLE;
 182                     CRYPTO_THREAD_unlock(long_memdbg_lock);
 183                 }
 184             }
 185         }
 186         break;
 187     }
 188     CRYPTO_THREAD_unlock(memdbg_lock);
 189     return ret;
 190 #endif
 191 }
 192
 193 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
 194
 195 static int mem_check_on(void)
 196 {
 197     int ret = 0;
 198     CRYPTO_THREAD_ID cur;
 199
 200     if (mh_mode & CRYPTO_MEM_CHECK_ON) {
 201         if (!RUN_ONCE(&memdbg_init, do_memdbg_init))
 202             return 0;
 203
 204         cur = CRYPTO_THREAD_get_current_id();
 205         CRYPTO_THREAD_read_lock(memdbg_lock);
 206
 207         ret = (mh_mode & CRYPTO_MEM_CHECK_ENABLE)
 208             || !CRYPTO_THREAD_compare_id(disabling_threadid, cur);
 209
 210         CRYPTO_THREAD_unlock(memdbg_lock);
 211     }
 212     return ret;
 213 }
 214
 215 static int mem_cmp(const MEM *a, const MEM *b)
 216 {
 217 #ifdef _WIN64
 218     const char *ap = (const char *)a->addr, *bp = (const char *)b->addr;
 219     if (ap == bp)
 220         return 0;
 221     else if (ap > bp)
 222         return 1;
 223     else
 224         return -1;
 225 #else
 226     return (const char *)a->addr - (const char *)b->addr;
 227 #endif
 228 }
 229
 230 static unsigned long mem_hash(const MEM *a)
 231 {
 232     size_t ret;
 233
 234     ret = (size_t)a->addr;
 235
 236     ret = ret * 17851 + (ret >> 14) * 7 + (ret >> 4) * 251;
 237     return ret;
 238 }
 239
 240 /* returns 1 if there was an info to pop, 0 if the stack was empty. */
 241 static int pop_info(void)
 242 {
 243     APP_INFO *current = NULL;
 244
 245     if (!RUN_ONCE(&memdbg_init, do_memdbg_init))
 246         return 0;
 247
 248     current = (APP_INFO *)CRYPTO_THREAD_get_local(&appinfokey);
 249     if (current != NULL) {
 250         APP_INFO *next = current->next;
 251
 252         if (next != NULL) {
 253             next->references++;
 254             CRYPTO_THREAD_set_local(&appinfokey, next);
 255         } else {
 256             CRYPTO_THREAD_set_local(&appinfokey, NULL);
 257         }
 258         if (--(current->references) <= 0) {
 259             current->next = NULL;
 260             if (next != NULL)
 261                 next->references--;
 262             OPENSSL_free(current);
 263         }
 264         return 1;
 265     }
 266     return 0;
 267 }
 268
 269 int CRYPTO_mem_debug_push(const char *info, const char *file, int line)
 270 {
 271     APP_INFO *ami, *amim;
 272     int ret = 0;
 273
 274     if (mem_check_on()) {
 275         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 276
 277         if (!RUN_ONCE(&memdbg_init, do_memdbg_init)
 278             || (ami = OPENSSL_malloc(sizeof(*ami))) == NULL)
 279             goto err;
 280
 281         ami->threadid = CRYPTO_THREAD_get_current_id();
 282         ami->file = file;
 283         ami->line = line;
 284         ami->info = info;
 285         ami->references = 1;
 286         ami->next = NULL;
 287
 288         amim = (APP_INFO *)CRYPTO_THREAD_get_local(&appinfokey);
 289         CRYPTO_THREAD_set_local(&appinfokey, ami);
 290
 291         if (amim != NULL)
 292             ami->next = amim;
 293         ret = 1;
 294  err:
 295         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 296     }
 297
 298     return ret;
 299 }
 300
 301 int CRYPTO_mem_debug_pop(void)
 302 {
 303     int ret = 0;
 304
 305     if (mem_check_on()) {
 306         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 307         ret = pop_info();
 308         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 309     }
 310     return ret;
 311 }
 312
 313 static unsigned long break_order_num = 0;
 314
 315 void CRYPTO_mem_debug_malloc(void *addr, size_t num, int before_p,
 316                              const char *file, int line)
 317 {
 318     MEM *m, *mm;
 319     APP_INFO *amim;
 320
 321     switch (before_p & 127) {
 322     case 0:
 323         break;
 324     case 1:
 325         if (addr == NULL)
 326             break;
 327
 328         if (mem_check_on()) {
 329             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 330
 331             if (!RUN_ONCE(&memdbg_init, do_memdbg_init)
 332                 || (m = OPENSSL_malloc(sizeof(*m))) == NULL) {
 333                 OPENSSL_free(addr);
 334                 CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 335                 return;
 336             }
 337             if (mh == NULL) {
 338                 if ((mh = lh_MEM_new(mem_hash, mem_cmp)) == NULL) {
 339                     OPENSSL_free(addr);
 340                     OPENSSL_free(m);
 341                     addr = NULL;
 342                     goto err;
 343                 }
 344             }
 345
 346             m->addr = addr;
 347             m->file = file;
 348             m->line = line;
 349             m->num = num;
 350             m->threadid = CRYPTO_THREAD_get_current_id();
 351
 352             if (order == break_order_num) {
 353                 /* BREAK HERE */
 354                 m->order = order;
 355             }
 356             m->order = order++;
 357 # ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
 358             m->array_siz = backtrace(m->array, OSSL_NELEM(m->array));
 359 # endif
 360             m->time = time(NULL);
 361
 362             amim = (APP_INFO *)CRYPTO_THREAD_get_local(&appinfokey);
 363             m->app_info = amim;
 364             if (amim != NULL)
 365                 amim->references++;
 366
 367             if ((mm = lh_MEM_insert(mh, m)) != NULL) {
 368                 /* Not good, but don't sweat it */
 369                 if (mm->app_info != NULL) {
 370                     mm->app_info->references--;
 371                 }
 372                 OPENSSL_free(mm);
 373             }
 374  err:
 375             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 376         }
 377         break;
 378     }
 379     return;
 380 }
 381
 382 void CRYPTO_mem_debug_free(void *addr, int before_p,
 383         const char *file, int line)
 384 {
 385     MEM m, *mp;
 386
 387     switch (before_p) {
 388     case 0:
 389         if (addr == NULL)
 390             break;
 391
 392         if (mem_check_on() && (mh != NULL)) {
 393             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 394
 395             m.addr = addr;
 396             mp = lh_MEM_delete(mh, &m);
 397             if (mp != NULL) {
 398                 app_info_free(mp->app_info);
 399                 OPENSSL_free(mp);
 400             }
 401
 402             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 403         }
 404         break;
 405     case 1:
 406         break;
 407     }
 408 }
 409
 410 void CRYPTO_mem_debug_realloc(void *addr1, void *addr2, size_t num,
 411                               int before_p, const char *file, int line)
 412 {
 413     MEM m, *mp;
 414
 415     switch (before_p) {
 416     case 0:
 417         break;
 418     case 1:
 419         if (addr2 == NULL)
 420             break;
 421
 422         if (addr1 == NULL) {
 423             CRYPTO_mem_debug_malloc(addr2, num, 128 | before_p, file, line);
 424             break;
 425         }
 426
 427         if (mem_check_on()) {
 428             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 429
 430             m.addr = addr1;
 431             mp = lh_MEM_delete(mh, &m);
 432             if (mp != NULL) {
 433                 mp->addr = addr2;
 434                 mp->num = num;
 435 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
 436                 mp->array_siz = backtrace(mp->array, OSSL_NELEM(mp->array));
 437 #endif
 438                 (void)lh_MEM_insert(mh, mp);
 439             }
 440
 441             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 442         }
 443         break;
 444     }
 445     return;
 446 }
 447
 448 typedef struct mem_leak_st {
 449     int (*print_cb) (const char *str, size_t len, void *u);
 450     void *print_cb_arg;
 451     int chunks;
 452     long bytes;
 453 } MEM_LEAK;
 454
 455 static void print_leak(const MEM *m, MEM_LEAK *l)
 456 {
 457     char buf[1024];
 458     char *bufp = buf;
 459     size_t len = sizeof(buf), ami_cnt;
 460     APP_INFO *amip;
 461     int n;
 462     struct tm *lcl = NULL;
 463     /*
 464      * Convert between CRYPTO_THREAD_ID (which could be anything at all) and
 465      * a long. This may not be meaningful depending on what CRYPTO_THREAD_ID is
 466      * but hopefully should give something sensible on most platforms
 467      */
 468     union {
 469         CRYPTO_THREAD_ID tid;
 470         unsigned long ltid;
 471     } tid;
 472     CRYPTO_THREAD_ID ti;
 473
 474     lcl = localtime(&m->time);
 475     n = BIO_snprintf(bufp, len, "[%02d:%02d:%02d] ",
 476                      lcl->tm_hour, lcl->tm_min, lcl->tm_sec);
 477     if (n <= 0) {
 478         bufp[0] = '\0';
 479         return;
 480     }
 481     bufp += n;
 482     len -= n;
 483
 484     n = BIO_snprintf(bufp, len, "%5lu file=%s, line=%d, ",
 485                      m->order, m->file, m->line);
 486     if (n <= 0)
 487         return;
 488     bufp += n;
 489     len -= n;
 490
 491     tid.ltid = 0;
 492     tid.tid = m->threadid;
 493     n = BIO_snprintf(bufp, len, "thread=%lu, ", tid.ltid);
 494     if (n <= 0)
 495         return;
 496     bufp += n;
 497     len -= n;
 498
 499     n = BIO_snprintf(bufp, len, "number=%d, address=%p\n", m->num, m->addr);
 500     if (n <= 0)
 501         return;
 502     bufp += n;
 503     len -= n;
 504
 505     l->print_cb(buf, (size_t)(bufp - buf), l->print_cb_arg);
 506
 507     l->chunks++;
 508     l->bytes += m->num;
 509
 510     amip = m->app_info;
 511     ami_cnt = 0;
 512
 513     if (amip) {
 514         ti = amip->threadid;
 515
 516         do {
 517             int buf_len;
 518             int info_len;
 519
 520             ami_cnt++;
 521             if (ami_cnt >= sizeof(buf) - 1)
 522                 break;
 523             memset(buf, '>', ami_cnt);
 524             buf[ami_cnt] = '\0';
 525             tid.ltid = 0;
 526             tid.tid = amip->threadid;
 527             n = BIO_snprintf(buf + ami_cnt, sizeof(buf) - ami_cnt,
 528                              " thread=%lu, file=%s, line=%d, info=\"",
 529                              tid.ltid, amip->file, amip->line);
 530             if (n <= 0)
 531                 break;
 532             buf_len = ami_cnt + n;
 533             info_len = strlen(amip->info);
 534             if (128 - buf_len - 3 < info_len) {
 535                 memcpy(buf + buf_len, amip->info, 128 - buf_len - 3);
 536                 buf_len = 128 - 3;
 537             } else {
 538                 n = BIO_snprintf(buf + buf_len, sizeof(buf) - buf_len, "%s",
 539                                  amip->info);
 540                 if (n < 0)
 541                     break;
 542                 buf_len += n;
 543             }
 544             n = BIO_snprintf(buf + buf_len, sizeof(buf) - buf_len, "\"\n");
 545             if (n <= 0)
 546                 break;
 547
 548             l->print_cb(buf, buf_len + n, l->print_cb_arg);
 549
 550             amip = amip->next;
 551         }
 552         while (amip && CRYPTO_THREAD_compare_id(amip->threadid, ti));
 553     }
 554
 555 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
 556     {
 557         size_t i;
 558         char **strings = backtrace_symbols(m->array, m->array_siz);
 559
 560         for (i = 0; i < m->array_siz; i++)
 561             fprintf(stderr, "##> %s\n", strings[i]);
 562         free(strings);
 563     }
 564 #endif
 565 }
 566
 567 IMPLEMENT_LHASH_DOALL_ARG_CONST(MEM, MEM_LEAK);
 568
 569 int CRYPTO_mem_leaks_cb(int (*cb) (const char *str, size_t len, void *u),
 570                         void *u)
 571 {
 572     MEM_LEAK ml;
 573
 574     /* Ensure all resources are released */
 575     OPENSSL_cleanup();
 576
 577     if (!RUN_ONCE(&memdbg_init, do_memdbg_init))
 578         return -1;
 579
 580     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 581
 582     ml.print_cb = cb;
 583     ml.print_cb_arg = u;
 584     ml.bytes = 0;
 585     ml.chunks = 0;
 586     if (mh != NULL)
 587         lh_MEM_doall_MEM_LEAK(mh, print_leak, &ml);
 588
 589     if (ml.chunks != 0) {
 590         char buf[256];
 591
 592         BIO_snprintf(buf, sizeof(buf), "%ld bytes leaked in %d chunks\n",
 593                      ml.bytes, ml.chunks);
 594         cb(buf, strlen(buf), u);
 595     } else {
 596         /*
 597          * Make sure that, if we found no leaks, memory-leak debugging itself
 598          * does not introduce memory leaks (which might irritate external
 599          * debugging tools). (When someone enables leak checking, but does not
 600          * call this function, we declare it to be their fault.)
 601          */
 602         int old_mh_mode;
 603
 604         CRYPTO_THREAD_write_lock(memdbg_lock);
 605
 606         /*
 607          * avoid deadlock when lh_free() uses CRYPTO_mem_debug_free(), which uses
 608          * mem_check_on
 609          */
 610         old_mh_mode = mh_mode;
 611         mh_mode = CRYPTO_MEM_CHECK_OFF;
 612
 613         lh_MEM_free(mh);
 614         mh = NULL;
 615
 616         mh_mode = old_mh_mode;
 617         CRYPTO_THREAD_unlock(memdbg_lock);
 618     }
 619     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_OFF);
 620
 621     /* Clean up locks etc */
 622     CRYPTO_THREAD_cleanup_local(&appinfokey);
 623     CRYPTO_THREAD_lock_free(memdbg_lock);
 624     CRYPTO_THREAD_lock_free(long_memdbg_lock);
 625     memdbg_lock = NULL;
 626     long_memdbg_lock = NULL;
 627
 628     return ml.chunks == 0 ? 1 : 0;
 629 }
 630
 631 static int print_bio(const char *str, size_t len, void *b)
 632 {
 633     return BIO_write((BIO *)b, str, len);
 634 }
 635
 636 int CRYPTO_mem_leaks(BIO *b)
 637 {
 638     /*
 639      * OPENSSL_cleanup() will free the ex_data locks so we can't have any
 640      * ex_data hanging around
 641      */
 642     bio_free_ex_data(b);
 643
 644     return CRYPTO_mem_leaks_cb(print_bio, b);
 645 }
 646
 647 # ifndef OPENSSL_NO_STDIO
 648 int CRYPTO_mem_leaks_fp(FILE *fp)
 649 {
 650     BIO *b;
 651     int ret;
 652
 653     /*
 654      * Need to turn off memory checking when allocated BIOs ... especially as
 655      * we're creating them at a time when we're trying to check we've not
 656      * left anything un-free()'d!!
 657      */
 658     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 659     b = BIO_new(BIO_s_file());
 660     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 661     if (b == NULL)
 662         return -1;
 663     BIO_set_fp(b, fp, BIO_NOCLOSE);
 664     ret = CRYPTO_mem_leaks_cb(print_bio, b);
 665     BIO_free(b);
 666     return ret;
 667 }
 668 # endif
 669
 670 #endif