freebsd-skq/lib/libc/gen/aux.c
kib 5a79777b44 Use aux vector to get values for SSP canary, pagesize, pagesizes array,
number of host CPUs and osreldate.

This eliminates the last sysctl(2) calls from the dynamically linked image
startup.

No objections from:	kan
Tested by:	marius (sparc64)
MFC after:	1 month
2010-08-17 09:13:26 +00:00

147 lines
3.4 KiB
C

/*-
* Copyright 2010 Konstantin Belousov <kib@FreeBSD.ORG>.
* All rights reserved.
*
* 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <elf.h>
#include <errno.h>
#include <link.h>
#include <pthread.h>
#include <string.h>
#include "un-namespace.h"
#include "libc_private.h"
Elf_Auxinfo *__elf_aux_vector;
static pthread_once_t aux_once = PTHREAD_ONCE_INIT;
static int pagesize, osreldate, canary_len, ncpus, pagesizes_len;
static char *canary, *pagesizes;
static void
init_aux(void)
{
Elf_Auxinfo *aux;
for (aux = __elf_aux_vector; aux->a_type != AT_NULL; aux++) {
switch (aux->a_type) {
case AT_CANARY:
canary = (char *)(aux->a_un.a_ptr);
break;
case AT_CANARYLEN:
canary_len = aux->a_un.a_val;
break;
case AT_PAGESIZES:
pagesizes = (char *)(aux->a_un.a_ptr);
break;
case AT_PAGESIZESLEN:
pagesizes_len = aux->a_un.a_val;
break;
case AT_PAGESZ:
pagesize = aux->a_un.a_val;
break;
case AT_OSRELDATE:
osreldate = aux->a_un.a_val;
break;
case AT_NCPUS:
ncpus = aux->a_un.a_val;
break;
}
}
}
int
_elf_aux_info(int aux, void *buf, int buflen)
{
int res;
if (__elf_aux_vector == NULL)
return (ENOSYS);
_once(&aux_once, init_aux);
switch (aux) {
case AT_CANARY:
if (canary != NULL && canary_len >= buflen) {
memcpy(buf, canary, buflen);
memset(canary, 0, canary_len);
canary = NULL;
res = 0;
} else
res = ENOENT;
break;
case AT_PAGESIZES:
if (pagesizes != NULL && pagesizes_len >= buflen) {
memcpy(buf, pagesizes, buflen);
res = 0;
} else
res = ENOENT;
break;
case AT_PAGESZ:
if (buflen == sizeof(int)) {
if (pagesize != 0) {
*(int *)buf = pagesize;
res = 0;
} else
res = ENOENT;
} else
res = EINVAL;
break;
case AT_OSRELDATE:
if (buflen == sizeof(int)) {
if (osreldate != 0) {
*(int *)buf = osreldate;
res = 0;
} else
res = ENOENT;
} else
res = EINVAL;
break;
case AT_NCPUS:
if (buflen == sizeof(int)) {
if (ncpus != 0) {
*(int *)buf = ncpus;
res = 0;
} else
res = ENOENT;
} else
res = EINVAL;
break;
default:
res = ENOENT;
break;
}
return (res);
}