crypto/mem_dbg.c

   1 /*
   2  * Copyright 1995-2019 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 static CRYPTO_ONCE memdbg_init = CRYPTO_ONCE_STATIC_INIT;
  43 CRYPTO_RWLOCK *memdbg_lock;
  44 static CRYPTO_RWLOCK *long_memdbg_lock;
  45
  46 /* memory-block description */
  47 struct mem_st {
  48     void *addr;
  49     int num;
  50     const char *file;
  51     int line;
  52     CRYPTO_THREAD_ID threadid;
  53     unsigned long order;
  54     time_t time;
  55 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
  56     void *array[30];
  57     size_t array_siz;
  58 #endif
  59 };
  60
  61 /*
  62  * hash-table of memory requests (address as * key); access requires
  63  * long_memdbg_lock lock
  64  */
  65 static LHASH_OF(MEM) *mh = NULL;
  66
  67 /* num_disable > 0 iff mh_mode == CRYPTO_MEM_CHECK_ON (w/o ..._ENABLE) */
  68 static unsigned int num_disable = 0;
  69
  70 /*
  71  * Valid iff num_disable > 0.  long_memdbg_lock is locked exactly in this
  72  * case (by the thread named in disabling_thread).
  73  */
  74 static CRYPTO_THREAD_ID disabling_threadid;
  75
  76 DEFINE_RUN_ONCE_STATIC(do_memdbg_init)
  77 {
  78     memdbg_lock = CRYPTO_THREAD_lock_new();
  79     long_memdbg_lock = CRYPTO_THREAD_lock_new();
  80     if (memdbg_lock == NULL || long_memdbg_lock == NULL) {
  81         CRYPTO_THREAD_lock_free(memdbg_lock);
  82         memdbg_lock = NULL;
  83         CRYPTO_THREAD_lock_free(long_memdbg_lock);
  84         long_memdbg_lock = NULL;
  85         return 0;
  86     }
  87     return 1;
  88 }
  89
  90 #endif
  91
  92 int CRYPTO_mem_ctrl(int mode)
  93 {
  94 #ifdef OPENSSL_NO_CRYPTO_MDEBUG
  95     return mode - mode;
  96 #else
  97     int ret = mh_mode;
  98
  99     if (!RUN_ONCE(&memdbg_init, do_memdbg_init))
 100         return -1;
 101
 102     CRYPTO_THREAD_write_lock(memdbg_lock);
 103     switch (mode) {
 104     default:
 105         break;
 106
 107     case CRYPTO_MEM_CHECK_ON:
 108         mh_mode = CRYPTO_MEM_CHECK_ON | CRYPTO_MEM_CHECK_ENABLE;
 109         num_disable = 0;
 110         break;
 111
 112     case CRYPTO_MEM_CHECK_OFF:
 113         mh_mode = 0;
 114         num_disable = 0;
 115         break;
 116
 117     /* switch off temporarily (for library-internal use): */
 118     case CRYPTO_MEM_CHECK_DISABLE:
 119         if (mh_mode & CRYPTO_MEM_CHECK_ON) {
 120             CRYPTO_THREAD_ID cur = CRYPTO_THREAD_get_current_id();
 121             /* see if we don't have long_memdbg_lock already */
 122             if (!num_disable
 123                 || !CRYPTO_THREAD_compare_id(disabling_threadid, cur)) {
 124                 /*
 125                  * Long-time lock long_memdbg_lock must not be claimed
 126                  * while we're holding memdbg_lock, or we'll deadlock
 127                  * if somebody else holds long_memdbg_lock (and cannot
 128                  * release it because we block entry to this function). Give
 129                  * them a chance, first, and then claim the locks in
 130                  * appropriate order (long-time lock first).
 131                  */
 132                 CRYPTO_THREAD_unlock(memdbg_lock);
 133                 /*
 134                  * Note that after we have waited for long_memdbg_lock and
 135                  * memdbg_lock, we'll still be in the right "case" and
 136                  * "if" branch because MemCheck_start and MemCheck_stop may
 137                  * never be used while there are multiple OpenSSL threads.
 138                  */
 139                 CRYPTO_THREAD_write_lock(long_memdbg_lock);
 140                 CRYPTO_THREAD_write_lock(memdbg_lock);
 141                 mh_mode &= ~CRYPTO_MEM_CHECK_ENABLE;
 142                 disabling_threadid = cur;
 143             }
 144             num_disable++;
 145         }
 146         break;
 147
 148     case CRYPTO_MEM_CHECK_ENABLE:
 149         if (mh_mode & CRYPTO_MEM_CHECK_ON) {
 150             if (num_disable) {  /* always true, or something is going wrong */
 151                 num_disable--;
 152                 if (num_disable == 0) {
 153                     mh_mode |= CRYPTO_MEM_CHECK_ENABLE;
 154                     CRYPTO_THREAD_unlock(long_memdbg_lock);
 155                 }
 156             }
 157         }
 158         break;
 159     }
 160     CRYPTO_THREAD_unlock(memdbg_lock);
 161     return ret;
 162 #endif
 163 }
 164
 165 #ifndef OPENSSL_NO_CRYPTO_MDEBUG
 166
 167 static int mem_check_on(void)
 168 {
 169     int ret = 0;
 170     CRYPTO_THREAD_ID cur;
 171
 172     if (mh_mode & CRYPTO_MEM_CHECK_ON) {
 173         if (!RUN_ONCE(&memdbg_init, do_memdbg_init))
 174             return 0;
 175
 176         cur = CRYPTO_THREAD_get_current_id();
 177         CRYPTO_THREAD_read_lock(memdbg_lock);
 178
 179         ret = (mh_mode & CRYPTO_MEM_CHECK_ENABLE)
 180             || !CRYPTO_THREAD_compare_id(disabling_threadid, cur);
 181
 182         CRYPTO_THREAD_unlock(memdbg_lock);
 183     }
 184     return ret;
 185 }
 186
 187 static int mem_cmp(const MEM *a, const MEM *b)
 188 {
 189 #ifdef _WIN64
 190     const char *ap = (const char *)a->addr, *bp = (const char *)b->addr;
 191     if (ap == bp)
 192         return 0;
 193     else if (ap > bp)
 194         return 1;
 195     else
 196         return -1;
 197 #else
 198     return (const char *)a->addr - (const char *)b->addr;
 199 #endif
 200 }
 201
 202 static unsigned long mem_hash(const MEM *a)
 203 {
 204     size_t ret;
 205
 206     ret = (size_t)a->addr;
 207
 208     ret = ret * 17851 + (ret >> 14) * 7 + (ret >> 4) * 251;
 209     return ret;
 210 }
 211
 212 #if !OPENSSL_API_3
 213 int CRYPTO_mem_debug_push(const char *info, const char *file, int line)
 214 {
 215     return 0;
 216 }
 217
 218 int CRYPTO_mem_debug_pop(void)
 219 {
 220     return 0;
 221 }
 222 #endif
 223
 224 static unsigned long break_order_num = 0;
 225
 226 void CRYPTO_mem_debug_malloc(void *addr, size_t num, int before_p,
 227                              const char *file, int line)
 228 {
 229     MEM *m, *mm;
 230
 231     switch (before_p & 127) {
 232     case 0:
 233         break;
 234     case 1:
 235         if (addr == NULL)
 236             break;
 237
 238         if (mem_check_on()) {
 239             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 240
 241             if (!RUN_ONCE(&memdbg_init, do_memdbg_init)
 242                 || (m = OPENSSL_malloc(sizeof(*m))) == NULL) {
 243                 OPENSSL_free(addr);
 244                 CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 245                 return;
 246             }
 247             if (mh == NULL) {
 248                 if ((mh = lh_MEM_new(mem_hash, mem_cmp)) == NULL) {
 249                     OPENSSL_free(addr);
 250                     OPENSSL_free(m);
 251                     addr = NULL;
 252                     goto err;
 253                 }
 254             }
 255
 256             m->addr = addr;
 257             m->file = file;
 258             m->line = line;
 259             m->num = num;
 260             m->threadid = CRYPTO_THREAD_get_current_id();
 261
 262             if (order == break_order_num) {
 263                 /* BREAK HERE */
 264                 m->order = order;
 265             }
 266             m->order = order++;
 267 # ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
 268             m->array_siz = backtrace(m->array, OSSL_NELEM(m->array));
 269 # endif
 270             m->time = time(NULL);
 271
 272             if ((mm = lh_MEM_insert(mh, m)) != NULL)
 273                 OPENSSL_free(mm);
 274  err:
 275             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 276         }
 277         break;
 278     }
 279     return;
 280 }
 281
 282 void CRYPTO_mem_debug_free(void *addr, int before_p,
 283         const char *file, int line)
 284 {
 285     MEM m, *mp;
 286
 287     switch (before_p) {
 288     case 0:
 289         if (addr == NULL)
 290             break;
 291
 292         if (mem_check_on() && (mh != NULL)) {
 293             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 294             m.addr = addr;
 295             mp = lh_MEM_delete(mh, &m);
 296             OPENSSL_free(mp);
 297             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 298         }
 299         break;
 300     case 1:
 301         break;
 302     }
 303 }
 304
 305 void CRYPTO_mem_debug_realloc(void *addr1, void *addr2, size_t num,
 306                               int before_p, const char *file, int line)
 307 {
 308     MEM m, *mp;
 309
 310     switch (before_p) {
 311     case 0:
 312         break;
 313     case 1:
 314         if (addr2 == NULL)
 315             break;
 316
 317         if (addr1 == NULL) {
 318             CRYPTO_mem_debug_malloc(addr2, num, 128 | before_p, file, line);
 319             break;
 320         }
 321
 322         if (mem_check_on()) {
 323             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 324
 325             m.addr = addr1;
 326             mp = lh_MEM_delete(mh, &m);
 327             if (mp != NULL) {
 328                 mp->addr = addr2;
 329                 mp->num = num;
 330 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
 331                 mp->array_siz = backtrace(mp->array, OSSL_NELEM(mp->array));
 332 #endif
 333                 (void)lh_MEM_insert(mh, mp);
 334             }
 335
 336             CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 337         }
 338         break;
 339     }
 340     return;
 341 }
 342
 343 typedef struct mem_leak_st {
 344     int (*print_cb) (const char *str, size_t len, void *u);
 345     void *print_cb_arg;
 346     int chunks;
 347     long bytes;
 348 } MEM_LEAK;
 349
 350 static void print_leak(const MEM *m, MEM_LEAK *l)
 351 {
 352     char buf[1024];
 353     char *bufp = buf, *hex;
 354     size_t len = sizeof(buf);
 355     int n;
 356     struct tm *lcl = NULL;
 357
 358     lcl = localtime(&m->time);
 359     n = BIO_snprintf(bufp, len, "[%02d:%02d:%02d] ",
 360                      lcl->tm_hour, lcl->tm_min, lcl->tm_sec);
 361     if (n <= 0) {
 362         bufp[0] = '\0';
 363         return;
 364     }
 365     bufp += n;
 366     len -= n;
 367
 368     n = BIO_snprintf(bufp, len, "%5lu file=%s, line=%d, ",
 369                      m->order, m->file, m->line);
 370     if (n <= 0)
 371         return;
 372     bufp += n;
 373     len -= n;
 374
 375     hex = OPENSSL_buf2hexstr((const unsigned char *)&m->threadid,
 376                              sizeof(m->threadid));
 377     n = BIO_snprintf(bufp, len, "thread=%s, number=%d, address=%p\n", hex,
 378                      m->num, m->addr);
 379     OPENSSL_free(hex);
 380     if (n <= 0)
 381         return;
 382     bufp += n;
 383     len -= n;
 384
 385     l->print_cb(buf, (size_t)(bufp - buf), l->print_cb_arg);
 386     l->chunks++;
 387     l->bytes += m->num;
 388
 389 #ifndef OPENSSL_NO_CRYPTO_MDEBUG_BACKTRACE
 390     {
 391         size_t i;
 392         char **strings = backtrace_symbols(m->array, m->array_siz);
 393
 394         for (i = 0; i < m->array_siz; i++)
 395             fprintf(stderr, "##> %s\n", strings[i]);
 396         free(strings);
 397     }
 398 #endif
 399 }
 400
 401 IMPLEMENT_LHASH_DOALL_ARG_CONST(MEM, MEM_LEAK);
 402
 403 int CRYPTO_mem_leaks_cb(int (*cb) (const char *str, size_t len, void *u),
 404                         void *u)
 405 {
 406     MEM_LEAK ml;
 407
 408     /* Ensure all resources are released */
 409     OPENSSL_cleanup();
 410
 411     if (!RUN_ONCE(&memdbg_init, do_memdbg_init))
 412         return -1;
 413
 414     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 415
 416     ml.print_cb = cb;
 417     ml.print_cb_arg = u;
 418     ml.bytes = 0;
 419     ml.chunks = 0;
 420     if (mh != NULL)
 421         lh_MEM_doall_MEM_LEAK(mh, print_leak, &ml);
 422
 423     if (ml.chunks != 0) {
 424         char buf[256];
 425
 426         BIO_snprintf(buf, sizeof(buf), "%ld bytes leaked in %d chunks\n",
 427                      ml.bytes, ml.chunks);
 428         cb(buf, strlen(buf), u);
 429     } else {
 430         /*
 431          * Make sure that, if we found no leaks, memory-leak debugging itself
 432          * does not introduce memory leaks (which might irritate external
 433          * debugging tools). (When someone enables leak checking, but does not
 434          * call this function, we declare it to be their fault.)
 435          */
 436         int old_mh_mode;
 437
 438         CRYPTO_THREAD_write_lock(memdbg_lock);
 439
 440         /*
 441          * avoid deadlock when lh_free() uses CRYPTO_mem_debug_free(), which uses
 442          * mem_check_on
 443          */
 444         old_mh_mode = mh_mode;
 445         mh_mode = CRYPTO_MEM_CHECK_OFF;
 446
 447         lh_MEM_free(mh);
 448         mh = NULL;
 449
 450         mh_mode = old_mh_mode;
 451         CRYPTO_THREAD_unlock(memdbg_lock);
 452     }
 453     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_OFF);
 454
 455     /* Clean up locks etc */
 456     CRYPTO_THREAD_lock_free(memdbg_lock);
 457     CRYPTO_THREAD_lock_free(long_memdbg_lock);
 458     memdbg_lock = NULL;
 459     long_memdbg_lock = NULL;
 460
 461     return ml.chunks == 0 ? 1 : 0;
 462 }
 463
 464 static int print_bio(const char *str, size_t len, void *b)
 465 {
 466     return BIO_write((BIO *)b, str, len);
 467 }
 468
 469 int CRYPTO_mem_leaks(BIO *b)
 470 {
 471     /*
 472      * OPENSSL_cleanup() will free the ex_data locks so we can't have any
 473      * ex_data hanging around
 474      */
 475     bio_free_ex_data(b);
 476
 477     return CRYPTO_mem_leaks_cb(print_bio, b);
 478 }
 479
 480 # ifndef OPENSSL_NO_STDIO
 481 int CRYPTO_mem_leaks_fp(FILE *fp)
 482 {
 483     BIO *b;
 484     int ret;
 485
 486     /*
 487      * Need to turn off memory checking when allocated BIOs ... especially as
 488      * we're creating them at a time when we're trying to check we've not
 489      * left anything un-free()'d!!
 490      */
 491     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE);
 492     b = BIO_new(BIO_s_file());
 493     CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE);
 494     if (b == NULL)
 495         return -1;
 496     BIO_set_fp(b, fp, BIO_NOCLOSE);
 497     ret = CRYPTO_mem_leaks_cb(print_bio, b);
 498     BIO_free(b);
 499     return ret;
 500 }
 501 # endif
 502
 503 #endif