malloc/tst-dynarray-fail.c

   1 /* Test allocation failures with dynamic arrays.
   2    Copyright (C) 2017-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 /* This test is separate from tst-dynarray because it cannot run under
  20    valgrind.  */
  21
  22 #include "tst-dynarray-shared.h"
  23
  24 #include <mcheck.h>
  25 #include <stdio.h>
  26 #include <support/check.h>
  27 #include <support/support.h>
  28 #include <support/xunistd.h>
  29 #include <sys/mman.h>
  30 #include <sys/resource.h>
  31 #include <unistd.h>
  32
  33 /* Data structure to fill up the heap.  */
  34 struct heap_filler
  35 {
  36   struct heap_filler *next;
  37 };
  38
  39 /* Allocate objects until the heap is full.  */
  40 static struct heap_filler *
  41 fill_heap (void)
  42 {
  43   size_t pad = 4096;
  44   struct heap_filler *head = NULL;
  45   while (true)
  46     {
  47       struct heap_filler *new_head = malloc (sizeof (*new_head) + pad);
  48       if (new_head == NULL)
  49         {
  50           if (pad > 0)
  51             {
  52               /* Try again with smaller allocations.  */
  53               pad = 0;
  54               continue;
  55             }
  56           else
  57             break;
  58         }
  59       new_head->next = head;
  60       head = new_head;
  61     }
  62   return head;
  63 }
  64
  65 /* Free the heap-filling allocations, so that we can continue testing
  66    and detect memory leaks elsewhere.  */
  67 static void
  68 free_fill_heap (struct heap_filler *head)
  69 {
  70   while (head != NULL)
  71     {
  72       struct heap_filler *next = head->next;
  73       free (head);
  74       head = next;
  75     }
  76 }
  77
  78 /* Check allocation failures for int arrays (without an element free
  79    function).  */
  80 static void
  81 test_int_fail (void)
  82 {
  83   /* Exercise failure in add/emplace.
  84
  85      do_add: Use emplace (false) or add (true) to add elements.
  86      do_finalize: Perform finalization at the end (instead of free).  */
  87   for (int do_add = 0; do_add < 2; ++do_add)
  88     for (int do_finalize = 0; do_finalize < 2; ++do_finalize)
  89       {
  90         struct dynarray_int dyn;
  91         dynarray_int_init (&dyn);
  92         size_t count = 0;
  93         while (true)
  94           {
  95             if (do_add)
  96               {
  97                 dynarray_int_add (&dyn, 0);
  98                 if (dynarray_int_has_failed (&dyn))
  99                   break;
 100               }
 101             else
 102               {
 103                 int *place = dynarray_int_emplace (&dyn);
 104                 if (place == NULL)
 105                   break;
 106                 TEST_VERIFY_EXIT (!dynarray_int_has_failed (&dyn));
 107                 *place = 0;
 108               }
 109             ++count;
 110           }
 111         printf ("info: %s: failure after %zu elements\n", __func__, count);
 112         TEST_VERIFY_EXIT (dynarray_int_has_failed (&dyn));
 113         if (do_finalize)
 114           {
 115             struct int_array result = { (int *) (uintptr_t) -1, -1 };
 116             TEST_VERIFY_EXIT (!dynarray_int_finalize (&dyn, &result));
 117             TEST_VERIFY_EXIT (result.array == (int *) (uintptr_t) -1);
 118             TEST_VERIFY_EXIT (result.length == (size_t) -1);
 119           }
 120         else
 121           dynarray_int_free (&dyn);
 122         CHECK_INIT_STATE (int, &dyn);
 123       }
 124
 125   /* Exercise failure in finalize.  */
 126   for (int do_add = 0; do_add < 2; ++do_add)
 127     {
 128       struct dynarray_int dyn;
 129       dynarray_int_init (&dyn);
 130       for (unsigned int i = 0; i < 10000; ++i)
 131         {
 132           if (do_add)
 133             {
 134               dynarray_int_add (&dyn, i);
 135               TEST_VERIFY_EXIT (!dynarray_int_has_failed (&dyn));
 136             }
 137           else
 138             {
 139               int *place = dynarray_int_emplace (&dyn);
 140               TEST_VERIFY_EXIT (place != NULL);
 141               *place = i;
 142             }
 143         }
 144       TEST_VERIFY_EXIT (!dynarray_int_has_failed (&dyn));
 145       struct heap_filler *heap_filler = fill_heap ();
 146       struct int_array result = { (int *) (uintptr_t) -1, -1 };
 147       TEST_VERIFY_EXIT (!dynarray_int_finalize (&dyn, &result));
 148       TEST_VERIFY_EXIT (result.array == (int *) (uintptr_t) -1);
 149       TEST_VERIFY_EXIT (result.length == (size_t) -1);
 150       CHECK_INIT_STATE (int, &dyn);
 151       free_fill_heap (heap_filler);
 152     }
 153
 154   /* Exercise failure in resize.  */
 155   {
 156     struct dynarray_int dyn;
 157     dynarray_int_init (&dyn);
 158     struct heap_filler *heap_filler = fill_heap ();
 159     TEST_VERIFY (!dynarray_int_resize (&dyn, 1000));
 160     TEST_VERIFY (dynarray_int_has_failed (&dyn));
 161     free_fill_heap (heap_filler);
 162
 163     dynarray_int_init (&dyn);
 164     TEST_VERIFY (dynarray_int_resize (&dyn, 1));
 165     heap_filler = fill_heap ();
 166     TEST_VERIFY (!dynarray_int_resize (&dyn, 1000));
 167     TEST_VERIFY (dynarray_int_has_failed (&dyn));
 168     free_fill_heap (heap_filler);
 169
 170     dynarray_int_init (&dyn);
 171     TEST_VERIFY (dynarray_int_resize (&dyn, 1000));
 172     heap_filler = fill_heap ();
 173     TEST_VERIFY (!dynarray_int_resize (&dyn, 2000));
 174     TEST_VERIFY (dynarray_int_has_failed (&dyn));
 175     free_fill_heap (heap_filler);
 176   }
 177 }
 178
 179 /* Check allocation failures for char * arrays (which automatically
 180    free the pointed-to strings).  */
 181 static void
 182 test_str_fail (void)
 183 {
 184   /* Exercise failure in add/emplace.
 185
 186      do_add: Use emplace (false) or add (true) to add elements.
 187      do_finalize: Perform finalization at the end (instead of free).  */
 188   for (int do_add = 0; do_add < 2; ++do_add)
 189     for (int do_finalize = 0; do_finalize < 2; ++do_finalize)
 190       {
 191         struct dynarray_str dyn;
 192         dynarray_str_init (&dyn);
 193         size_t count = 0;
 194         while (true)
 195           {
 196             char **place;
 197             if (do_add)
 198               {
 199                 dynarray_str_add (&dyn, NULL);
 200                 if (dynarray_str_has_failed (&dyn))
 201                   break;
 202                 else
 203                   place = dynarray_str_at (&dyn, dynarray_str_size (&dyn) - 1);
 204               }
 205             else
 206               {
 207                 place = dynarray_str_emplace (&dyn);
 208                 if (place == NULL)
 209                   break;
 210               }
 211             TEST_VERIFY_EXIT (!dynarray_str_has_failed (&dyn));
 212             TEST_VERIFY_EXIT (*place == NULL);
 213             *place = strdup ("placeholder");
 214             if (*place == NULL)
 215               {
 216                 /* Second loop to wait for failure of
 217                    dynarray_str_emplace.  */
 218                 while (true)
 219                   {
 220                     if (do_add)
 221                       {
 222                         dynarray_str_add (&dyn, NULL);
 223                         if (dynarray_str_has_failed (&dyn))
 224                           break;
 225                       }
 226                     else
 227                       {
 228                         char **place = dynarray_str_emplace (&dyn);
 229                         if (place == NULL)
 230                           break;
 231                         TEST_VERIFY_EXIT (!dynarray_str_has_failed (&dyn));
 232                         *place = NULL;
 233                       }
 234                     ++count;
 235                   }
 236                 break;
 237               }
 238             ++count;
 239           }
 240         printf ("info: %s: failure after %zu elements\n", __func__, count);
 241         TEST_VERIFY_EXIT (dynarray_str_has_failed (&dyn));
 242         if (do_finalize)
 243           {
 244             struct str_array result = { (char **) (uintptr_t) -1, -1 };
 245             TEST_VERIFY_EXIT (!dynarray_str_finalize (&dyn, &result));
 246             TEST_VERIFY_EXIT (result.array == (char **) (uintptr_t) -1);
 247             TEST_VERIFY_EXIT (result.length == (size_t) -1);
 248           }
 249         else
 250           dynarray_str_free (&dyn);
 251         TEST_VERIFY_EXIT (!dynarray_str_has_failed (&dyn));
 252         TEST_VERIFY_EXIT (dyn.u.dynarray_header.array == dyn.scratch);
 253         TEST_VERIFY_EXIT (dynarray_str_size (&dyn) == 0);
 254         TEST_VERIFY_EXIT (dyn.u.dynarray_header.allocated > 0);
 255       }
 256
 257   /* Exercise failure in finalize.  */
 258   for (int do_add = 0; do_add < 2; ++do_add)
 259     {
 260       struct dynarray_str dyn;
 261       dynarray_str_init (&dyn);
 262       for (unsigned int i = 0; i < 1000; ++i)
 263         {
 264           if (do_add)
 265             dynarray_str_add (&dyn, xstrdup ("placeholder"));
 266           else
 267             {
 268               char **place = dynarray_str_emplace (&dyn);
 269               TEST_VERIFY_EXIT (place != NULL);
 270               TEST_VERIFY_EXIT (*place == NULL);
 271               *place = xstrdup ("placeholder");
 272             }
 273         }
 274       TEST_VERIFY_EXIT (!dynarray_str_has_failed (&dyn));
 275       struct heap_filler *heap_filler = fill_heap ();
 276       struct str_array result = { (char **) (uintptr_t) -1, -1 };
 277       TEST_VERIFY_EXIT (!dynarray_str_finalize (&dyn, &result));
 278       TEST_VERIFY_EXIT (result.array == (char **) (uintptr_t) -1);
 279       TEST_VERIFY_EXIT (result.length == (size_t) -1);
 280       TEST_VERIFY_EXIT (!dynarray_str_has_failed (&dyn));
 281       TEST_VERIFY_EXIT (dyn.u.dynarray_header.array == dyn.scratch);
 282       TEST_VERIFY_EXIT (dynarray_str_size (&dyn) == 0);
 283       TEST_VERIFY_EXIT (dyn.u.dynarray_header.allocated > 0);
 284       free_fill_heap (heap_filler);
 285     }
 286
 287   /* Exercise failure in resize.  */
 288   {
 289     struct dynarray_str dyn;
 290     dynarray_str_init (&dyn);
 291     struct heap_filler *heap_filler = fill_heap ();
 292     TEST_VERIFY (!dynarray_str_resize (&dyn, 1000));
 293     TEST_VERIFY (dynarray_str_has_failed (&dyn));
 294     free_fill_heap (heap_filler);
 295
 296     dynarray_str_init (&dyn);
 297     TEST_VERIFY (dynarray_str_resize (&dyn, 1));
 298     *dynarray_str_at (&dyn, 0) = xstrdup ("allocated");
 299     heap_filler = fill_heap ();
 300     TEST_VERIFY (!dynarray_str_resize (&dyn, 1000));
 301     TEST_VERIFY (dynarray_str_has_failed (&dyn));
 302     free_fill_heap (heap_filler);
 303
 304     dynarray_str_init (&dyn);
 305     TEST_VERIFY (dynarray_str_resize (&dyn, 1000));
 306     *dynarray_str_at (&dyn, 0) = xstrdup ("allocated");
 307     heap_filler = fill_heap ();
 308     TEST_VERIFY (!dynarray_str_resize (&dyn, 2000));
 309     TEST_VERIFY (dynarray_str_has_failed (&dyn));
 310     free_fill_heap (heap_filler);
 311   }
 312 }
 313
 314 /* Test if mmap can allocate a page.  This is necessary because
 315    setrlimit does not fail even if it reduces the RLIMIT_AS limit
 316    below what is currently needed by the process.  */
 317 static bool
 318 mmap_works (void)
 319 {
 320   void *ptr =  mmap (NULL, 1, PROT_READ | PROT_WRITE,
 321                      MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
 322   if (ptr == MAP_FAILED)
 323     return false;
 324   xmunmap (ptr, 1);
 325   return true;
 326 }
 327
 328 /* Set the RLIMIT_AS limit to the value in *LIMIT.  */
 329 static void
 330 xsetrlimit_as (const struct rlimit *limit)
 331 {
 332   if (setrlimit (RLIMIT_AS, limit) != 0)
 333     FAIL_EXIT1 ("setrlimit (RLIMIT_AS, %lu): %m",
 334                 (unsigned long) limit->rlim_cur);
 335 }
 336
 337 /* Approximately this many bytes can be allocated after
 338    reduce_rlimit_as has run.  */
 339 enum { as_limit_reserve = 2 * 1024 * 1024 };
 340
 341 /* Limit the size of the process, so that memory allocation in
 342    allocate_thread will eventually fail, without impacting the entire
 343    system.  By default, a dynamic limit which leaves room for 2 MiB is
 344    activated.  The TEST_RLIMIT_AS environment variable overrides
 345    it.  */
 346 static void
 347 reduce_rlimit_as (void)
 348 {
 349   struct rlimit limit;
 350   if (getrlimit (RLIMIT_AS, &limit) != 0)
 351     FAIL_EXIT1 ("getrlimit (RLIMIT_AS) failed: %m");
 352
 353   /* Use the TEST_RLIMIT_AS setting if available.  */
 354   {
 355     long target = 0;
 356     const char *variable = "TEST_RLIMIT_AS";
 357     const char *target_str = getenv (variable);
 358     if (target_str != NULL)
 359       {
 360         target = atoi (target_str);
 361         if (target <= 0)
 362           FAIL_EXIT1 ("invalid %s value: \"%s\"", variable, target_str);
 363         printf ("info: setting RLIMIT_AS to %ld MiB\n", target);
 364         target *= 1024 * 1024;      /* Convert to megabytes.  */
 365         limit.rlim_cur = target;
 366         xsetrlimit_as (&limit);
 367         return;
 368       }
 369   }
 370
 371   /* Otherwise, try to find the limit with a binary search.  */
 372   unsigned long low = 1 << 20;
 373   limit.rlim_cur = low;
 374   xsetrlimit_as (&limit);
 375
 376   /* Find working upper limit.  */
 377   unsigned long high = 1 << 30;
 378   while (true)
 379     {
 380       limit.rlim_cur = high;
 381       xsetrlimit_as (&limit);
 382       if (mmap_works ())
 383         break;
 384       if (2 * high < high)
 385         FAIL_EXIT1 ("cannot find upper AS limit");
 386       high *= 2;
 387     }
 388
 389   /* Perform binary search.  */
 390   while ((high - low) > 128 * 1024)
 391     {
 392       unsigned long middle = (low + high) / 2;
 393       limit.rlim_cur = middle;
 394       xsetrlimit_as (&limit);
 395       if (mmap_works ())
 396         high = middle;
 397       else
 398         low = middle;
 399     }
 400
 401   unsigned long target = high + as_limit_reserve;
 402   limit.rlim_cur = target;
 403   xsetrlimit_as (&limit);
 404   printf ("info: RLIMIT_AS limit: %lu bytes\n", target);
 405 }
 406
 407 static int
 408 do_test (void)
 409 {
 410   mtrace ();
 411   reduce_rlimit_as ();
 412   test_int_fail ();
 413   test_str_fail ();
 414   return 0;
 415 }
 416
 417 #define TIMEOUT 90
 418 #include <support/test-driver.c>