1/* Copyright (C) 2013-2024 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <errno.h>
19#include <malloc.h>
20#include <stdint.h>
21#include <stdio.h>
22#include <string.h>
23#include <libc-diag.h>
24#include <support/check.h>
25
26static int
27do_test (void)
28{
29 void *p;
30 unsigned char *c;
31 int save, i, ok;
32
33 errno = 0;
34
35 /* realloc (NULL, ...) behaves similarly to malloc (C89). */
36 DIAG_PUSH_NEEDS_COMMENT;
37#if __GNUC_PREREQ (7, 0)
38 /* GCC 7 warns about too-large allocations; here we want to test
39 that they fail. */
40 DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
41#endif
42 p = realloc (NULL, size: -1);
43 DIAG_POP_NEEDS_COMMENT;
44 save = errno;
45
46 if (p != NULL)
47 FAIL_EXIT1 ("realloc (NULL, -1) succeeded.");
48
49 /* errno should be set to ENOMEM on failure (POSIX). */
50 if (p == NULL && save != ENOMEM)
51 FAIL_EXIT1 ("errno is not set correctly");
52
53 errno = 0;
54
55 /* realloc (NULL, ...) behaves similarly to malloc (C89). */
56 p = realloc (NULL, size: 10);
57 save = errno;
58
59 if (p == NULL)
60 FAIL_EXIT1 ("realloc (NULL, 10) failed.");
61
62 free (ptr: p);
63
64 p = calloc (nmemb: 20, size: 1);
65 if (p == NULL)
66 FAIL_EXIT1 ("calloc (20, 1) failed.");
67
68 /* Check increasing size preserves contents (C89). */
69 p = realloc (ptr: p, size: 200);
70 if (p == NULL)
71 FAIL_EXIT1 ("realloc (p, 200) failed.");
72
73 c = p;
74 ok = 1;
75
76 for (i = 0; i < 20; i++)
77 {
78 if (c[i] != 0)
79 ok = 0;
80 }
81
82 if (ok == 0)
83 FAIL_EXIT1 ("first 20 bytes were not cleared");
84
85 free (ptr: p);
86
87 p = realloc (NULL, size: 100);
88 if (p == NULL)
89 FAIL_EXIT1 ("realloc (NULL, 100) failed.");
90
91 memset (p, 0xff, 100);
92
93 /* Check decreasing size preserves contents (C89). */
94 p = realloc (ptr: p, size: 16);
95 if (p == NULL)
96 FAIL_EXIT1 ("realloc (p, 16) failed.");
97
98 c = p;
99 ok = 1;
100
101 for (i = 0; i < 16; i++)
102 {
103 if (c[i] != 0xff)
104 ok = 0;
105 }
106
107 if (ok == 0)
108 FAIL_EXIT1 ("first 16 bytes were not correct");
109
110 /* Check failed realloc leaves original untouched (C89). */
111 DIAG_PUSH_NEEDS_COMMENT;
112#if __GNUC_PREREQ (7, 0)
113 /* GCC 7 warns about too-large allocations; here we want to test
114 that they fail. */
115 DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
116#endif
117 c = realloc (ptr: p, size: -1);
118 DIAG_POP_NEEDS_COMMENT;
119 if (c != NULL)
120 FAIL_EXIT1 ("realloc (p, -1) succeeded.");
121
122 c = p;
123 ok = 1;
124
125 for (i = 0; i < 16; i++)
126 {
127 if (c[i] != 0xff)
128 ok = 0;
129 }
130
131 if (ok == 0)
132 FAIL_EXIT1 ("first 16 bytes were not correct after failed realloc");
133
134 /* realloc (p, 0) frees p (C89) and returns NULL (glibc). */
135 p = realloc (ptr: p, size: 0);
136 if (p != NULL)
137 FAIL_EXIT1 ("realloc (p, 0) returned non-NULL.");
138
139 /* realloc (NULL, 0) acts like malloc (0) (glibc). */
140 p = realloc (NULL, size: 0);
141 if (p == NULL)
142 FAIL_EXIT1 ("realloc (NULL, 0) returned NULL.");
143
144 free (ptr: p);
145
146 /* Smoke test to make sure that allocations do not move if they have enough
147 space to expand in the chunk. */
148 for (size_t sz = 3; sz < 256 * 1024; sz += 2048)
149 {
150 p = realloc (NULL, size: sz);
151 if (p == NULL)
152 FAIL_EXIT1 ("realloc (NULL, %zu) returned NULL.", sz);
153 size_t newsz = malloc_usable_size (ptr: p);
154 printf (format: "size: %zu, usable size: %zu, extra: %zu\n",
155 sz, newsz, newsz - sz);
156 uintptr_t oldp = (uintptr_t) p;
157 void *new_p = realloc (ptr: p, size: newsz);
158 if ((uintptr_t) new_p != oldp)
159 FAIL_EXIT1 ("Expanding (%zu bytes) to usable size (%zu) moved block",
160 sz, newsz);
161 free (ptr: new_p);
162
163 /* We encountered a large enough extra size at least once. */
164 if (newsz - sz > 1024)
165 break;
166 }
167
168 return 0;
169}
170
171#define TEST_FUNCTION do_test ()
172#include "../test-skeleton.c"
173

source code of glibc/malloc/tst-realloc.c