about summary refs log tree commit diff
path: root/malloc/tst-mallocstate.c
blob: 704ec88a6ece6590a47d8e9fc4346a260f139fbd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
/* Emulate Emacs heap dumping to test malloc_set_state.
   Copyright (C) 2001-2023 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <libc-symbols.h>
#include <shlib-compat.h>
#include <support/check.h>
#include <support/support.h>
#include <support/test-driver.h>

#include "malloc.h"

/* Make the compatibility symbols availabile to this test case.  */
void *malloc_get_state (void);
compat_symbol_reference (libc, malloc_get_state, malloc_get_state, GLIBC_2_0);
int malloc_set_state (void *);
compat_symbol_reference (libc, malloc_set_state, malloc_set_state, GLIBC_2_0);

/* Maximum object size in the fake heap.  */
enum { max_size = 64 };

/* Allocation actions.  These are randomized actions executed on the
   dumped heap (see allocation_tasks below).  They are interspersed
   with operations on the new heap (see heap_activity).  */
enum allocation_action
  {
    action_free,                /* Dumped and freed.  */
    action_realloc,             /* Dumped and realloc'ed.  */
    action_realloc_same,        /* Dumped and realloc'ed, same size.  */
    action_realloc_smaller,     /* Dumped and realloc'ed, shrinked.  */
    action_count
  };

/* Dumped heap.  Initialize it, so that the object is placed into the
   .data section, for increased realism.  The size is an upper bound;
   we use about half of the space.  */
static size_t dumped_heap[action_count * max_size * max_size
                          / sizeof (size_t)] = {1};

/* Next free space in the dumped heap.  Also top of the heap at the
   end of the initialization procedure.  */
static size_t *next_heap_chunk;

/* Copied from malloc.c and hooks.c.  The version is deliberately
   lower than the final version of malloc_set_state.  */
# define NBINS 128
# define MALLOC_STATE_MAGIC   0x444c4541l
# define MALLOC_STATE_VERSION (0 * 0x100l + 4l)
static struct
{
  long magic;
  long version;
  void *av[NBINS * 2 + 2];
  char *sbrk_base;
  int sbrked_mem_bytes;
  unsigned long trim_threshold;
  unsigned long top_pad;
  unsigned int n_mmaps_max;
  unsigned long mmap_threshold;
  int check_action;
  unsigned long max_sbrked_mem;
  unsigned long max_total_mem;
  unsigned int n_mmaps;
  unsigned int max_n_mmaps;
  unsigned long mmapped_mem;
  unsigned long max_mmapped_mem;
  int using_malloc_checking;
  unsigned long max_fast;
  unsigned long arena_test;
  unsigned long arena_max;
  unsigned long narenas;
} save_state =
  {
    .magic = MALLOC_STATE_MAGIC,
    .version = MALLOC_STATE_VERSION,
  };

/* Allocate a blob in the fake heap.  */
static void *
dumped_heap_alloc (size_t length)
{
  /* malloc needs three state bits in the size field, so the minimum
     alignment is 8 even on 32-bit architectures.  malloc_set_state
     should be compatible with such heaps even if it currently
     provides more alignment to applications.  */
  enum
  {
    heap_alignment = 8,
    heap_alignment_mask = heap_alignment - 1
  };
  _Static_assert (sizeof (size_t) <= heap_alignment,
                  "size_t compatible with heap alignment");

  /* Need at least this many bytes for metadata and application
     data. */
  size_t chunk_size = sizeof (size_t) + length;
  /* Round up the allocation size to the heap alignment.  */
  chunk_size += heap_alignment_mask;
  chunk_size &= ~heap_alignment_mask;
  TEST_VERIFY_EXIT ((chunk_size & 3) == 0);
  if (next_heap_chunk == NULL)
    /* Initialize the top of the heap.  Add one word of zero padding,
       to match existing practice.  */
    {
      dumped_heap[0] = 0;
      next_heap_chunk = dumped_heap + 1;
    }
  else
    /* The previous chunk is allocated. */
    chunk_size |= 1;
  *next_heap_chunk = chunk_size;

  /* User data starts after the chunk header.  */
  void *result = next_heap_chunk + 1;
  next_heap_chunk += chunk_size / sizeof (size_t);

  /* Mark the previous chunk as used.   */
  *next_heap_chunk = 1;
  return result;
}

/* Global seed variable for the random number generator.  */
static unsigned long long global_seed;

/* Simple random number generator.  The numbers are in the range from
   0 to UINT_MAX (inclusive).  */
static unsigned int
rand_next (unsigned long long *seed)
{
  /* Linear congruential generated as used for MMIX.  */
  *seed = *seed * 6364136223846793005ULL + 1442695040888963407ULL;
  return *seed >> 32;
}

/* Fill LENGTH bytes at BUFFER with random contents, as determined by
   SEED.  */
static void
randomize_buffer (unsigned char *buffer, size_t length,
                  unsigned long long seed)
{
  for (size_t i = 0; i < length; ++i)
    buffer[i] = rand_next (&seed);
}

/* Dumps the buffer to standard output,  in hexadecimal.  */
static void
dump_hex (unsigned char *buffer, size_t length)
{
  for (int i = 0; i < length; ++i)
    printf (" %02X", buffer[i]);
}

/* Set to true if an error is encountered.  */
static bool errors = false;

/* Keep track of object allocations.  */
struct allocation
{
  unsigned char *data;
  unsigned int size;
  unsigned int seed;
};

/* Check that the allocation task allocation has the expected
   contents.  */
static void
check_allocation (const struct allocation *alloc, int index)
{
  size_t size = alloc->size;
  if (alloc->data == NULL)
    {
      printf ("error: NULL pointer for allocation of size %zu at %d, seed %u\n",
              size, index, alloc->seed);
      errors = true;
      return;
    }

  unsigned char expected[4096];
  if (size > sizeof (expected))
    {
      printf ("error: invalid allocation size %zu at %d, seed %u\n",
              size, index, alloc->seed);
      errors = true;
      return;
    }
  randomize_buffer (expected, size, alloc->seed);
  if (memcmp (alloc->data, expected, size) != 0)
    {
      printf ("error: allocation %d data mismatch, size %zu, seed %u\n",
              index, size, alloc->seed);
      printf ("  expected:");
      dump_hex (expected, size);
      putc ('\n', stdout);
      printf ("    actual:");
      dump_hex (alloc->data, size);
      putc ('\n', stdout);
      errors = true;
    }
}

/* A heap allocation combined with pending actions on it.  */
struct allocation_task
{
  struct allocation allocation;
  enum allocation_action action;
};

/* Allocation tasks.  Initialized by init_allocation_tasks and used by
   perform_allocations.  */
enum { allocation_task_count = action_count * max_size };
static struct allocation_task allocation_tasks[allocation_task_count];

/* Fisher-Yates shuffle of allocation_tasks.  */
static void
shuffle_allocation_tasks (void)
{
  for (int i = 0; i < allocation_task_count - 1; ++i)
    {
      /* Pick pair in the tail of the array.  */
      int j = i + (rand_next (&global_seed)
                   % ((unsigned) (allocation_task_count - i)));
      TEST_VERIFY_EXIT (j >= 0 && j < allocation_task_count);
      /* Exchange. */
      struct allocation_task tmp = allocation_tasks[i];
      allocation_tasks[i] = allocation_tasks[j];
      allocation_tasks[j] = tmp;
    }
}

/* Set up the allocation tasks and the dumped heap.  */
static void
initial_allocations (void)
{
  /* Initialize in a position-dependent way.  */
  for (int i = 0; i < allocation_task_count; ++i)
    allocation_tasks[i] = (struct allocation_task)
      {
        .allocation =
          {
            .size = 1 + (i / action_count),
            .seed = i,
          },
        .action = i % action_count
      };

  /* Execute the tasks in a random order.  */
  shuffle_allocation_tasks ();

  /* Initialize the contents of the dumped heap.   */
  for (int i = 0; i < allocation_task_count; ++i)
    {
      struct allocation_task *task = allocation_tasks + i;
      task->allocation.data = dumped_heap_alloc (task->allocation.size);
      randomize_buffer (task->allocation.data, task->allocation.size,
                        task->allocation.seed);
    }

  for (int i = 0; i < allocation_task_count; ++i)
    check_allocation (&allocation_tasks[i].allocation, i);
}

/* Indicates whether init_heap has run.  This variable needs to be
   volatile because malloc is declared __THROW, which implies it is a
   leaf function, but we expect it to run our hooks.  */
static volatile bool heap_initialized;

/* Executed by glibc malloc, through __malloc_initialize_hook
   below.  */
static void
init_heap (void)
{
  if (test_verbose)
    printf ("info: performing heap initialization\n");
  heap_initialized = true;

  /* Populate the dumped heap.  */
  initial_allocations ();

  /* Complete initialization of the saved heap data structure.  */
  save_state.sbrk_base = (void *) dumped_heap;
  save_state.sbrked_mem_bytes = sizeof (dumped_heap);
  /* Top pointer.  Adjust so that it points to the start of struct
     malloc_chunk.  */
  save_state.av[2] = (void *) (next_heap_chunk - 1);

  /* Integrate the dumped heap into the process heap.  */
  TEST_VERIFY_EXIT (malloc_set_state (&save_state) == 0);
}

/* Interpose the initialization callback.  */
void (*volatile __malloc_initialize_hook) (void) = init_heap;
compat_symbol_reference (libc, __malloc_initialize_hook,
                         __malloc_initialize_hook, GLIBC_2_0);

/* Simulate occasional unrelated heap activity in the non-dumped
   heap.  */
enum { heap_activity_allocations_count = 32 };
static struct allocation heap_activity_allocations
  [heap_activity_allocations_count] = {};
static int heap_activity_seed_counter = 1000 * 1000;

static void
heap_activity (void)
{
  /* Only do this from time to time.  */
  if ((rand_next (&global_seed) % 4) == 0)
    {
      int slot = rand_next (&global_seed) % heap_activity_allocations_count;
      struct allocation *alloc = heap_activity_allocations + slot;
      if (alloc->data == NULL)
        {
          alloc->size = rand_next (&global_seed) % (4096U + 1);
          alloc->data = xmalloc (alloc->size);
          alloc->seed = heap_activity_seed_counter++;
          randomize_buffer (alloc->data, alloc->size, alloc->seed);
          check_allocation (alloc, 1000 + slot);
        }
      else
        {
          check_allocation (alloc, 1000 + slot);
          free (alloc->data);
          alloc->data = NULL;
        }
    }
}

static void
heap_activity_deallocate (void)
{
  for (int i = 0; i < heap_activity_allocations_count; ++i)
    free (heap_activity_allocations[i].data);
}

/* Perform a full heap check across the dumped heap allocation tasks,
   and the simulated heap activity directly above.  */
static void
full_heap_check (void)
{
  /* Dumped heap.  */
  for (int i = 0; i < allocation_task_count; ++i)
    if (allocation_tasks[i].allocation.data != NULL)
      check_allocation (&allocation_tasks[i].allocation, i);

  /* Heap activity allocations.  */
  for (int i = 0; i < heap_activity_allocations_count; ++i)
    if (heap_activity_allocations[i].data != NULL)
      check_allocation (heap_activity_allocations + i, i);
}

/* Used as an optimization barrier to force a heap allocation.  */
__attribute__ ((noinline, noclone))
static void
my_free (void *ptr)
{
  free (ptr);
}

static int
do_test (void)
{
  my_free (malloc (1));
  TEST_VERIFY_EXIT (heap_initialized);

  /* The first pass performs the randomly generated allocation
     tasks.  */
  if (test_verbose)
    printf ("info: first pass through allocation tasks\n");
  full_heap_check ();

  /* Execute the post-undump tasks in a random order.  */
  shuffle_allocation_tasks ();

  for (int i = 0; i < allocation_task_count; ++i)
    {
      heap_activity ();
      struct allocation_task *task = allocation_tasks + i;
      switch (task->action)
        {
        case action_free:
          check_allocation (&task->allocation, i);
          free (task->allocation.data);
          task->allocation.data = NULL;
          break;

        case action_realloc:
          check_allocation (&task->allocation, i);
          task->allocation.data = xrealloc
            (task->allocation.data, task->allocation.size + max_size);
          check_allocation (&task->allocation, i);
          break;

        case action_realloc_same:
          check_allocation (&task->allocation, i);
          task->allocation.data = xrealloc
            (task->allocation.data, task->allocation.size);
          check_allocation (&task->allocation, i);
          break;

        case action_realloc_smaller:
          check_allocation (&task->allocation, i);
          size_t new_size = task->allocation.size - 1;
          task->allocation.data = xrealloc (task->allocation.data, new_size);
          if (new_size == 0)
            {
              if (task->allocation.data != NULL)
                {
                  printf ("error: realloc with size zero did not deallocate\n");
                  errors = true;
                }
              /* No further action on this task.  */
              task->action = action_free;
            }
          else
            {
              task->allocation.size = new_size;
              check_allocation (&task->allocation, i);
            }
          break;

        case action_count:
          FAIL_EXIT1 ("task->action should never be action_count");
        }
      full_heap_check ();
    }

  /* The second pass frees the objects which were allocated during the
     first pass.  */
  if (test_verbose)
    printf ("info: second pass through allocation tasks\n");

  shuffle_allocation_tasks ();
  for (int i = 0; i < allocation_task_count; ++i)
    {
      heap_activity ();
      struct allocation_task *task = allocation_tasks + i;
      switch (task->action)
        {
        case action_free:
          /* Already freed, nothing to do.  */
          break;

        case action_realloc:
        case action_realloc_same:
        case action_realloc_smaller:
          check_allocation (&task->allocation, i);
          free (task->allocation.data);
          task->allocation.data = NULL;
          break;

        case action_count:
          FAIL_EXIT1 ("task->action should never be action_count");
        }
      full_heap_check ();
    }

  heap_activity_deallocate ();

  /* Check that the malloc_get_state stub behaves in the intended
     way.  */
  errno = 0;
  if (malloc_get_state () != NULL)
    {
      printf ("error: malloc_get_state succeeded\n");
      errors = true;
    }
  if (errno != ENOSYS)
    {
      printf ("error: malloc_get_state: %m\n");
      errors = true;
    }

  return errors;
}

#include <support/test-driver.c>