freebsd-dev/lib/libkse/thread/thr_sigaltstack.c

108 lines
3.0 KiB
C

/*-
* Copyright (c) 2003 David Xu <davidxu@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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <errno.h>
#include <signal.h>
#include "thr_private.h"
__weak_reference(_sigaltstack, sigaltstack);
int
_sigaltstack(stack_t *_ss, stack_t *_oss)
{
struct pthread *curthread = _get_curthread();
stack_t ss, oss;
int oonstack, errsave, ret;
kse_critical_t crit;
if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM) {
crit = _kse_critical_enter();
ret = __sys_sigaltstack(_ss, _oss);
errsave = errno;
/* Get a copy */
if (ret == 0 && _ss != NULL)
curthread->sigstk = *_ss;
_kse_critical_leave(crit);
errno = errsave;
return (ret);
}
if (_ss)
ss = *_ss;
if (_oss)
oss = *_oss;
/* Should get and set stack in atomic way */
crit = _kse_critical_enter();
oonstack = _thr_sigonstack(&ss);
if (_oss != NULL) {
oss = curthread->sigstk;
oss.ss_flags = (curthread->sigstk.ss_flags & SS_DISABLE)
? SS_DISABLE : ((oonstack) ? SS_ONSTACK : 0);
}
if (_ss != NULL) {
if (oonstack) {
_kse_critical_leave(crit);
errno = EPERM;
return (-1);
}
if ((ss.ss_flags & ~SS_DISABLE) != 0) {
_kse_critical_leave(crit);
errno = EINVAL;
return (-1);
}
if (!(ss.ss_flags & SS_DISABLE)) {
if (ss.ss_size < MINSIGSTKSZ) {
_kse_critical_leave(crit);
errno = ENOMEM;
return (-1);
}
curthread->sigstk = ss;
} else {
curthread->sigstk.ss_flags |= SS_DISABLE;
}
}
_kse_critical_leave(crit);
if (_oss != NULL)
*_oss = oss;
return (0);
}
int
_thr_sigonstack(void *sp)
{
struct pthread *curthread = _get_curthread();
return ((curthread->sigstk.ss_flags & SS_DISABLE) == 0 ?
(((size_t)sp - (size_t)curthread->sigstk.ss_sp) < curthread->sigstk.ss_size)
: 0);
}