2 * Copyright (c) 2011 Alex Hornung <alex@alexhornung.com>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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
13 * the documentation and/or other materials provided with the
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
19 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
20 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
22 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/types.h>
38 struct safe_mem_hdr *prev;
39 struct safe_mem_hdr *next;
40 struct safe_mem_tail *tail;
44 char sig[8]; /* SAFEMEM */
47 struct safe_mem_tail {
48 char sig[8]; /* SAFEMEM */
51 static struct safe_mem_hdr *safe_mem_hdr_first = NULL;
54 _alloc_safe_mem(size_t req_sz, const char *file, int line)
56 struct safe_mem_hdr *hdr, *hdrp;
57 struct safe_mem_tail *tail;
61 alloc_sz = req_sz + sizeof(*hdr) + sizeof(*tail);
62 if ((mem = malloc(alloc_sz)) == NULL)
65 if (mlock(mem, alloc_sz) < 0) {
70 memset(mem, 0, alloc_sz);
72 hdr = (struct safe_mem_hdr *)mem;
73 tail = (struct safe_mem_tail *)(mem + alloc_sz - sizeof(*tail));
74 user_mem = mem + sizeof(*hdr);
76 strcpy(hdr->sig, "SAFEMEM");
77 strcpy(tail->sig, "SAFEMEM");
79 hdr->alloc_sz = alloc_sz;
84 if (safe_mem_hdr_first == NULL) {
85 safe_mem_hdr_first = hdr;
87 hdrp = safe_mem_hdr_first;
88 while (hdrp->next != NULL)
98 _free_safe_mem(void *mem_ptr, const char *file, int line)
100 struct safe_mem_hdr *hdr;
101 struct safe_mem_tail *tail;
106 hdr = (struct safe_mem_hdr *)mem;
107 tail = (struct safe_mem_tail *)(mem + hdr->alloc_sz - sizeof(*tail));
110 fprintf(stderr, "freeing safe_mem (hdr): %#lx (%s:%d)\n",
111 (unsigned long)(void *)hdr, hdr->file, hdr->line);
114 if (hdr->alloc_sz == 0) {
115 fprintf(stderr, "BUG: double-free at %s:%d !!!\n", file, line);
119 /* Integrity checks */
120 if ((memcmp(hdr->sig, "SAFEMEM\0", 8) != 0) ||
121 (memcmp(tail->sig, "SAFEMEM\0", 8) != 0)) {
122 fprintf(stderr, "BUG: safe_mem buffer under- or overflow at "
123 "%s:%d !!!\n", file, line);
127 if (safe_mem_hdr_first == NULL) {
128 fprintf(stderr, "BUG: safe_mem list should not be empty at "
129 "%s:%d !!!\n", file, line);
133 if (hdr->prev != NULL)
134 hdr->prev->next = hdr->next;
135 if (hdr->next != NULL)
136 hdr->next->prev = hdr->prev;
137 if (safe_mem_hdr_first == hdr)
138 safe_mem_hdr_first = hdr->next;
140 alloc_sz = hdr->alloc_sz;
141 memset(mem, 0xFF, alloc_sz);
142 memset(mem, 0, alloc_sz);
148 check_and_purge_safe_mem(void)
150 struct safe_mem_hdr *hdr;
156 if (safe_mem_hdr_first == NULL)
159 hdr = safe_mem_hdr_first;
160 while ((hdr = safe_mem_hdr_first) != NULL) {
162 if ((hdr->alloc_sz > 0) &&
163 (memcmp(hdr->sig, "SAFEMEM\0", 8) == 0) &&
164 (memcmp(hdr->tail->sig, "SAFEMEM\0", 8) == 0))
169 fprintf(stderr, "un-freed safe_mem: %#lx (%s:%d) [integrity=%s]\n",
170 (unsigned long)(void *)hdr, hdr->file, hdr->line,
171 ok? "ok" : "failed");
175 _free_safe_mem(mem, "check_and_purge_safe_mem", 0);