util.c revision 1.18 
1/*	$OpenBSD: util.c,v 1.18 2004/06/14 15:07:36 millert 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#define	_dl_round_page(x)	(((x) + (__LDPGSZ - 1)) & ~(__LDPGSZ - 1))
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 */
79void *
80_dl_malloc(size_t need)
81{
82	long *p, *t, *n, have;
83
84	need = (need + 8 + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1);
85
86	if ((t = _dl_malloc_free) != 0) {	/* Try free list first */
87		n = (long *)&_dl_malloc_free;
88		while (t && t[-1] < need) {
89			n = t;
90			t = (long *)*t;
91		}
92		if (t) {
93			*n = *t;
94			_dl_memset(t, 0, t[-1] - sizeof(long));
95			return((void *)t);
96		}
97	}
98	have = _dl_round_page((long)_dl_malloc_pool) - (long)_dl_malloc_pool;
99	if (need > have) {
100		if (have >= 8 + DL_MALLOC_ALIGN) {
101			p = _dl_malloc_pool;
102			*p = have;
103			_dl_free((void *)(p + 1));	/* move to freelist */
104		}
105		_dl_malloc_pool = (void *)_dl_mmap((void *)0,
106		    _dl_round_page(need), PROT_READ|PROT_WRITE,
107		    MAP_ANON|MAP_PRIVATE, -1, 0);
108		if (_dl_malloc_pool == 0 || _dl_malloc_pool == MAP_FAILED ) {
109			_dl_printf("Dynamic loader failure: malloc.\n");
110			_dl_exit(7);
111		}
112	}
113	p = _dl_malloc_pool;
114	_dl_malloc_pool += need;
115	_dl_memset(p, 0, need);
116	*p = need;
117	return((void *)(p + 1));
118}
119
120void
121_dl_free(void *p)
122{
123	long *t = (long *)p;
124
125	*t = (long)_dl_malloc_free;
126	_dl_malloc_free = p;
127}
128
129
130unsigned int
131_dl_random(void)
132{
133	int mib[2];
134	unsigned int rnd;
135	size_t len;
136
137	mib[0] = CTL_KERN;
138	mib[1] = KERN_ARND;
139	len = sizeof(rnd);
140	_dl_sysctl(mib, 2, &rnd, &len, NULL, 0);
141
142	return (rnd);
143}
144
145
146