glibc/sysdeps/mach/hurd/sigaltstack.c

63 lines
1.7 KiB
C

/* Copyright (C) 1992-2023 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, see
<https://www.gnu.org/licenses/>. */
#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 (const stack_t *argss, stack_t *oss)
{
struct hurd_sigstate *s;
stack_t ss, old;
/* Fault before taking any locks. */
if (argss != NULL)
ss = *argss;
if (oss != NULL)
*(volatile stack_t *) 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;
}
libc_hidden_def (__sigaltstack)
weak_alias (__sigaltstack, sigaltstack)