1 /*
2  * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
3  * Copyright (c) 2015-2017 The strace developers.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #ifdef HAVE_CONFIG_H
30 # include "config.h"
31 #endif
32 
33 #include <stdlib.h>
34 #include <string.h>
35 
36 #include "error_prints.h"
37 #include "xmalloc.h"
38 
39 static void
die_out_of_memory(void)40 die_out_of_memory(void)
41 {
42 	static int recursed;
43 
44 	if (recursed)
45 		exit(1);
46 	recursed = 1;
47 
48 	error_msg_and_die("Out of memory");
49 }
50 
51 void *
xmalloc(size_t size)52 xmalloc(size_t size)
53 {
54 	void *p = malloc(size);
55 
56 	if (!p)
57 		die_out_of_memory();
58 
59 	return p;
60 }
61 
62 void *
xcalloc(size_t nmemb,size_t size)63 xcalloc(size_t nmemb, size_t size)
64 {
65 	void *p = calloc(nmemb, size);
66 
67 	if (!p)
68 		die_out_of_memory();
69 
70 	return p;
71 }
72 
73 #define HALF_SIZE_T	(((size_t) 1) << (sizeof(size_t) * 4))
74 
75 void *
xreallocarray(void * ptr,size_t nmemb,size_t size)76 xreallocarray(void *ptr, size_t nmemb, size_t size)
77 {
78 	size_t bytes = nmemb * size;
79 
80 	if ((nmemb | size) >= HALF_SIZE_T &&
81 	    size && bytes / size != nmemb)
82 		die_out_of_memory();
83 
84 	void *p = realloc(ptr, bytes);
85 
86 	if (!p)
87 		die_out_of_memory();
88 
89 	return p;
90 }
91 
92 void *
xgrowarray(void * const ptr,size_t * const nmemb,const size_t memb_size)93 xgrowarray(void *const ptr, size_t *const nmemb, const size_t memb_size)
94 {
95 	/* this is the same value as glibc DEFAULT_MXFAST */
96 	enum { DEFAULT_ALLOC_SIZE = 64 * SIZEOF_LONG / 4 };
97 
98 	size_t grow_memb;
99 
100 	if (ptr == NULL)
101 		grow_memb = *nmemb ? 0 :
102 			(DEFAULT_ALLOC_SIZE + memb_size - 1) / memb_size;
103 	else
104 		grow_memb = (*nmemb >> 1) + 1;
105 
106 	if ((*nmemb + grow_memb) < *nmemb)
107 		die_out_of_memory();
108 
109 	*nmemb += grow_memb;
110 
111 	return xreallocarray(ptr, *nmemb, memb_size);
112 }
113 
114 char *
xstrdup(const char * str)115 xstrdup(const char *str)
116 {
117 	if (!str)
118 		return NULL;
119 
120 	char *p = strdup(str);
121 
122 	if (!p)
123 		die_out_of_memory();
124 
125 	return p;
126 }
127 
128 char *
xstrndup(const char * str,size_t n)129 xstrndup(const char *str, size_t n)
130 {
131 	char *p;
132 
133 	if (!str)
134 		return NULL;
135 
136 #ifdef HAVE_STRNDUP
137 	p = strndup(str, n);
138 #else
139 	p = xmalloc(n + 1);
140 #endif
141 
142 	if (!p)
143 		die_out_of_memory();
144 
145 #ifndef HAVE_STRNDUP
146 	strncpy(p, str, n);
147 	p[n] = '\0';
148 #endif
149 
150 	return p;
151 }
152