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/* $OpenBSD: util.c,v 1.27 2013/11/13 05:41:42 deraadt Exp $ */
/*
* Copyright (c) 1998 Per Fogelstrom, Opsycon AB
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/mman.h>
#include <sys/sysctl.h>
#include <string.h>
#include "archdep.h"
/*
* Stack protector dummies.
* Ideally, a scheme to compile these stubs from libc should be used, but
* this would end up dragging too much code from libc here.
*/
long __guard[8] __dso_public __attribute__((section(".openbsd.randomdata")));
long __guard_local __dso_hidden __attribute__((section(".openbsd.randomdata")));
void __stack_smash_handler(char [], int);
void
__stack_smash_handler(char func[], int damaged)
{
_dl_exit(127);
}
/*
* Static vars usable after bootstrapping.
*/
static char *_dl_malloc_pool;
static long *_dl_malloc_free;
char *
_dl_strdup(const char *orig)
{
char *newstr;
int len;
len = _dl_strlen(orig)+1;
newstr = _dl_malloc(len);
_dl_strlcpy(newstr, orig, len);
return (newstr);
}
/*
* The following malloc/free code is a very simplified implementation
* of a malloc function. However, we do not need to be very complex here
* because we only free memory when 'dlclose()' is called and we can
* reuse at least the memory allocated for the object descriptor. We have
* one dynamic string allocated, the library name and it is likely that
* we can reuse that one too without a lot of complex collapsing code.
*/
void *
_dl_malloc(size_t need)
{
long *p, *t, *n, have;
need = (need + 2*DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1);
if ((t = _dl_malloc_free) != 0) { /* Try free list first */
n = (long *)&_dl_malloc_free;
while (t && t[-1] < need) {
n = t;
t = (long *)*t;
}
if (t) {
*n = *t;
_dl_memset(t, 0, t[-1] - DL_MALLOC_ALIGN);
return((void *)t);
}
}
have = _dl_round_page((long)_dl_malloc_pool) - (long)_dl_malloc_pool;
if (need > have) {
if (have >= 8 + DL_MALLOC_ALIGN) {
p = (void *)_dl_malloc_pool;
p = (void *) ((long)p + DL_MALLOC_ALIGN);
p[-1] = have;
_dl_free((void *)p); /* move to freelist */
}
_dl_malloc_pool = (void *)_dl_mmap((void *)0,
_dl_round_page(need), PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, -1, 0);
if (_dl_malloc_pool == 0 || _dl_mmap_error(_dl_malloc_pool)) {
_dl_printf("Dynamic loader failure: malloc.\n");
_dl_exit(7);
}
}
p = (void *)_dl_malloc_pool;
_dl_malloc_pool += need;
_dl_memset(p, 0, need);
p = (void *) ((long)p + DL_MALLOC_ALIGN);
p[-1] = need;
return (p);
}
void
_dl_free(void *p)
{
long *t = (long *)p;
*t = (long)_dl_malloc_free;
_dl_malloc_free = p;
}
void
_dl_randombuf(void *buf, size_t buflen)
{
const int mib[2] = { CTL_KERN, KERN_ARND };
_dl_sysctl(mib, 2, buf, &buflen, NULL, 0);
}
unsigned int
_dl_random(void)
{
unsigned int rnd;
_dl_randombuf(&rnd, sizeof(rnd));
return (rnd);
}
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