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/* Copyright (C) 1992, 93, 94, 95, 97, 98 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <hurd.h>
#include <hurd/signal.h>
/* Run signals handlers on the stack specified by SS (if not NULL).
If OSS is not NULL, it is filled in with the old signal stack status. */
int
__sigaltstack (argss, oss)
const struct sigaltstack *argss;
struct sigaltstack *oss;
{
struct hurd_sigstate *s;
struct sigaltstack ss, old;
/* Fault before taking any locks. */
if (argss != NULL)
ss = *argss;
if (oss != NULL)
*(volatile struct sigaltstack *) oss = *oss;
s = _hurd_self_sigstate ();
__spin_lock (&s->lock);
if (argss != NULL &&
(ss.ss_flags & SS_DISABLE) && (s->sigaltstack.ss_flags & SS_ONSTACK))
{
/* Can't disable a stack that is in use. */
__spin_unlock (&s->lock);
errno = EINVAL;
return -1;
}
old = s->sigaltstack;
if (argss != NULL)
s->sigaltstack = ss;
__spin_unlock (&s->lock);
if (oss != NULL)
*oss = old;
return 0;
}
weak_alias(__sigaltstack, sigaltstack)
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