util.c revision 1.19 
1/*	$OpenBSD: util.c,v 1.19 2007/02/09 14:51:13 drahn 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 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 */
28
29#include <sys/types.h>
30#include <sys/param.h>
31#include <sys/mman.h>
32#include <sys/sysctl.h>
33#include <string.h>
34#include "archdep.h"
35
36/*
37 * Stack protector dummies.
38 * Ideally, a scheme to compile these stubs from libc should be used, but
39 * this would end up dragging too much code from libc here.
40 */
41long __guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
42
43void __stack_smash_handler(char [], int);
44
45void
46__stack_smash_handler(char func[], int damaged)
47{
48	_dl_exit(127);
49}
50
51/*
52 * Static vars usable after bootstrapping.
53 */
54static void *_dl_malloc_pool = 0;
55static long *_dl_malloc_free = 0;
56
57char *
58_dl_strdup(const char *orig)
59{
60	char *newstr;
61	int len;
62
63	len = _dl_strlen(orig)+1;
64	newstr = _dl_malloc(len);
65	_dl_strlcpy(newstr, orig, len);
66	return (newstr);
67}
68
69
70/*
71 * The following malloc/free code is a very simplified implementation
72 * of a malloc function. However, we do not need to be very complex here
73 * because we only free memory when 'dlclose()' is called and we can
74 * reuse at least the memory allocated for the object descriptor. We have
75 * one dynamic string allocated, the library name and it is likely that
76 * we can reuse that one to without a lot of complex colapsing code.
77 */
78void *
79_dl_malloc(size_t need)
80{
81	long *p, *t, *n, have;
82
83	need = (need + 8 + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1);
84
85	if ((t = _dl_malloc_free) != 0) {	/* Try free list first */
86		n = (long *)&_dl_malloc_free;
87		while (t && t[-1] < need) {
88			n = t;
89			t = (long *)*t;
90		}
91		if (t) {
92			*n = *t;
93			_dl_memset(t, 0, t[-1] - sizeof(long));
94			return((void *)t);
95		}
96	}
97	have = _dl_round_page((long)_dl_malloc_pool) - (long)_dl_malloc_pool;
98	if (need > have) {
99		if (have >= 8 + DL_MALLOC_ALIGN) {
100			p = _dl_malloc_pool;
101			*p = have;
102			_dl_free((void *)(p + 1));	/* move to freelist */
103		}
104		_dl_malloc_pool = (void *)_dl_mmap((void *)0,
105		    _dl_round_page(need), PROT_READ|PROT_WRITE,
106		    MAP_ANON|MAP_PRIVATE, -1, 0);
107		if (_dl_malloc_pool == 0 || _dl_malloc_pool == MAP_FAILED ) {
108			_dl_printf("Dynamic loader failure: malloc.\n");
109			_dl_exit(7);
110		}
111	}
112	p = _dl_malloc_pool;
113	_dl_malloc_pool += need;
114	_dl_memset(p, 0, need);
115	*p = need;
116	return((void *)(p + 1));
117}
118
119void
120_dl_free(void *p)
121{
122	long *t = (long *)p;
123
124	*t = (long)_dl_malloc_free;
125	_dl_malloc_free = p;
126}
127
128
129unsigned int
130_dl_random(void)
131{
132	int mib[2];
133	unsigned int rnd;
134	size_t len;
135
136	mib[0] = CTL_KERN;
137	mib[1] = KERN_ARND;
138	len = sizeof(rnd);
139	_dl_sysctl(mib, 2, &rnd, &len, NULL, 0);
140
141	return (rnd);
142}
143
144
145