uclibc-ng/libc/signal/sigaction.c

/* Copyright (C) 1997-2000,2002,2003,2005,2006 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
   <http://www.gnu.org/licenses/>.  */

#include <signal.h>
#include <sys/syscall.h>

#if defined __NR_rt_sigaction

/* If ACT is not NULL, change the action for SIG to *ACT.
   If OACT is not NULL, put the old action for SIG in *OACT.  */
int
__libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
{
	if (unlikely (sig == SIGCANCEL || sig == SIGSETXID)) {
		__set_errno (EINVAL);
		return -1;
	}

	/* NB: kernel (as of 2.6.25) will return EINVAL
	 * if sizeof(act->sa_mask) does not match kernel's sizeof(sigset_t).
	 * Try to catch this problem at uclibc build time:  */
	struct BUG_sigset_size {
		int BUG_sigset_size
			[sizeof(act->sa_mask) == _NSIG / 8 ? 1 : -1];
	};
	return __syscall_rt_sigaction(sig, act, oact, sizeof(act->sa_mask));
}

#else
# define __need_NULL
# include <stddef.h>
# include <bits/kernel_sigaction.h>

/* If ACT is not NULL, change the action for SIG to *ACT.
   If OACT is not NULL, put the old action for SIG in *OACT.  */
int
__libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
{
	int result;
	struct old_kernel_sigaction kact, koact;

	if (unlikely (sig == SIGCANCEL || sig == SIGSETXID)) {
		__set_errno (EINVAL);
		return -1;
	}

	if (act) {
		kact.k_sa_handler = act->sa_handler;
		kact.sa_mask = act->sa_mask.__val[0];
		kact.sa_flags = act->sa_flags;
# ifdef HAVE_SA_RESTORER
		kact.sa_restorer = act->sa_restorer;
# endif
	}
	result = __syscall_sigaction(sig,
			act ? &kact : NULL,
			oact ? &koact : NULL);
	if (oact && result >= 0) {
		oact->sa_handler = koact.k_sa_handler;
		oact->sa_mask.__val[0] = koact.sa_mask;
		oact->sa_flags = koact.sa_flags;
# ifdef HAVE_SA_RESTORER
		oact->sa_restorer = koact.sa_restorer;
# endif
	}
	return result;
}

#endif


#ifndef LIBC_SIGACTION
# ifndef __UCLIBC_HAS_THREADS__
strong_alias(__libc_sigaction,sigaction)
libc_hidden_def(sigaction)
# else
weak_alias(__libc_sigaction,sigaction)
libc_hidden_weak(sigaction)
# endif
#endif