mes/lib/linux/signal.c

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/* -*-comment-start: "//";comment-end:""-*-
* GNU Mes --- Maxwell Equations of Software
* Copyright © 2018,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
*
* This file is part of GNU Mes.
*
* GNU Mes is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* GNU Mes 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
*/
#if __x86_64__
void
_restorer (void)
{
_sys_call (SYS_rt_sigreturn);
}
#endif
# define __sigmask(sig) \
(((unsigned long int) 1) << (((sig) - 1) % (8 * sizeof (unsigned long int))))
sighandler_t
signal (int signum, sighandler_t action)
{
#if __i386__
return _sys_call2 (SYS_signal, signum, action);
#else
static struct sigaction setup_action = {-1};
static struct sigaction old = {0};
setup_action.sa_handler = action;
setup_action.sa_restorer = _restorer;
setup_action.sa_mask = __sigmask (signum);
old.sa_handler = SIG_DFL;
setup_action.sa_flags = SA_RESTORER | SA_RESTART;
int r = _sys_call4 (SYS_rt_sigaction, signum, &setup_action, &old, sizeof (sigset_t));
if (r)
return 0;
return old.sa_handler;
#endif
}