util.c revision 1.12 
1/*	$OpenBSD: util.c,v 1.12 2002/12/02 23:17:36 deraadt Exp $	*/
2
3/*
4 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
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. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed under OpenBSD by
17 *	Per Fogelstrom, Opsycon AB, Sweden.
18 * 4. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
22 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
25 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 */
34
35#include <sys/types.h>
36#include <sys/mman.h>
37#include <string.h>
38#include "archdep.h"
39
40/*
41 * Stack protector dummies.
42 * Ideally, a scheme to compile these stubs from libc should be used, but
43 * this would end up dragging too much code from libc here.
44 */
45long __guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
46void
47__stack_smash_handler(char func[], int damaged)
48{
49	_dl_exit(127);
50}
51
52/*
53 * Static vars usable after bootstrapping.
54 */
55static void *_dl_malloc_base;
56static void *_dl_malloc_pool = 0;
57static long *_dl_malloc_free = 0;
58
59char *
60_dl_strdup(const char *orig)
61{
62	char *newstr;
63	int len;
64
65	len = _dl_strlen(orig)+1;
66	newstr = _dl_malloc(len);
67	_dl_strlcpy(newstr, orig, len);
68	return (newstr);
69}
70
71/*
72 *  The following malloc/free code is a very simplified implementation
73 *  of a malloc function. However, we do not need to be very complex here
74 *  because we only free memory when 'dlclose()' is called and we can
75 *  reuse at least the memory allocated for the object descriptor. We have
76 *  one dynamic string allocated, the library name and it is likely that
77 *  we can reuse that one to without a lot of complex colapsing code.
78 */
79
80void *
81_dl_malloc(size_t size)
82{
83	long *p, *t, *n;
84
85	size = (size + 8 + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1);
86
87	if ((t = _dl_malloc_free) != 0) {	/* Try free list first */
88		n = (long *)&_dl_malloc_free;
89		while (t && t[-1] < size) {
90			n = t;
91			t = (long *)*t;
92		}
93		if (t) {
94			*n = *t;
95			_dl_memset(t, 0, t[-1] - 4);
96			return((void *)t);
97		}
98	}
99	if (_dl_malloc_pool == 0 ||
100	    _dl_malloc_pool + size > _dl_malloc_base + 4096) {
101		_dl_malloc_pool = (void *)_dl_mmap((void *)0, 4096,
102		    PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
103		if (_dl_malloc_pool == 0 || _dl_malloc_pool == MAP_FAILED ) {
104			_dl_printf("Dynamic loader failure: malloc.\n");
105			_dl_exit(7);
106		}
107		_dl_malloc_base = _dl_malloc_pool;
108	}
109	p = _dl_malloc_pool;
110	_dl_malloc_pool += size;
111	_dl_memset(p, 0, size);
112	*p = size;
113	return((void *)(p + 1));
114}
115
116void
117_dl_free(void *p)
118{
119	long *t = (long *)p;
120
121	*t = (long)_dl_malloc_free;
122	_dl_malloc_free = p;
123}
124