1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright 1996-1998 John D. Polstra.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include <sys/param.h>
29 #include <machine/cpu.h>
30 #include <machine/cpufunc.h>
31 #include <stddef.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <unistd.h>
35 #include "rtld.h"
36 #include "rtld_printf.h"
37 #include "rtld_malloc.h"
38 #include "rtld_libc.h"
39
40 static int rtld_malloc_spinlock;
41
42 /*
43 * Almost always the rtld malloc is called under the write-locked rtld
44 * bind lock. Due to this, xlock() would need a single CAS to take
45 * the spinlock. But some places only own read-locked rtld bind lock,
46 * and then the spinlock protects the malloc structures from the
47 * parallel updates.
48 */
49 static void
xlock(void)50 xlock(void)
51 {
52 while (atomic_cmpset_acq_int(&rtld_malloc_spinlock, 0, 1) == 0)
53 cpu_spinwait();
54 }
55
56 static void
xunlock(void)57 xunlock(void)
58 {
59 atomic_store_rel_int(&rtld_malloc_spinlock, 0);
60 }
61
62 void *
xcalloc(size_t number,size_t size)63 xcalloc(size_t number, size_t size)
64 {
65 void *p;
66
67 xlock();
68 p = __crt_calloc(number, size);
69 xunlock();
70 if (p == NULL) {
71 rtld_fdputstr(STDERR_FILENO, "Out of memory\n");
72 _exit(1);
73 }
74 return (p);
75 }
76
77 void *
xmalloc(size_t size)78 xmalloc(size_t size)
79 {
80 void *p;
81
82 xlock();
83 p = __crt_malloc(size);
84 xunlock();
85 if (p == NULL) {
86 rtld_fdputstr(STDERR_FILENO, "Out of memory\n");
87 _exit(1);
88 }
89 return (p);
90 }
91
92 char *
xstrdup(const char * str)93 xstrdup(const char *str)
94 {
95 char *copy;
96 size_t len;
97
98 len = strlen(str) + 1;
99 copy = xmalloc(len);
100 memcpy(copy, str, len);
101 return (copy);
102 }
103
104 void *
xmalloc_aligned(size_t size,size_t align,size_t offset)105 xmalloc_aligned(size_t size, size_t align, size_t offset)
106 {
107 void *res;
108
109 offset &= align - 1;
110 if (align < sizeof(void *))
111 align = sizeof(void *);
112
113 xlock();
114 res = __crt_aligned_alloc_offset(align, size, offset);
115 xunlock();
116 if (res == NULL) {
117 rtld_fdputstr(STDERR_FILENO, "Out of memory\n");
118 _exit(1);
119 }
120 return (res);
121 }
122
123 void *
malloc(size_t size)124 malloc(size_t size)
125 {
126 void *p;
127
128 xlock();
129 p = __crt_malloc(size);
130 xunlock();
131 return (p);
132 }
133
134 void *
calloc(size_t num,size_t size)135 calloc(size_t num, size_t size)
136 {
137 void *p;
138
139 xlock();
140 p = __crt_calloc(num, size);
141 xunlock();
142 return (p);
143 }
144
145 void
free(void * cp)146 free(void *cp)
147 {
148 xlock();
149 __crt_free(cp);
150 xunlock();
151 }
152
153 void *
realloc(void * cp,size_t nbytes)154 realloc(void *cp, size_t nbytes)
155 {
156 void *p;
157
158 xlock();
159 p = __crt_realloc(cp, nbytes);
160 xunlock();
161 return (p);
162 }
163