sigaction.c

/* Copyright (C) 1997-2014 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 <errno.h>
#include <signal.h>
#include <string.h>

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

#define SA_RESTORER	0x04000000

/* The difference here is that the sigaction structure used in the
   kernel is not the same as we use in the libc.  Therefore we must
   translate it here.  */
#include <kernel_sigaction.h>

int
__libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
{
  int result;
  struct kernel_sigaction kact;
  struct kernel_sigaction koact;

  if (act)
    {
      kact.k_sa_handler = act->sa_handler;
      memcpy (&kact.sa_mask, &act->sa_mask, sizeof (sigset_t));
      kact.sa_flags = act->sa_flags;
#ifdef HAVE_SA_RESTORER
      if (kact.sa_flags & SA_RESTORER)
	kact.sa_restorer = act->sa_restorer;
#endif
    }

  result = INLINE_SYSCALL (rt_sigaction, 4, sig,
			   act ? &kact : NULL,
			   oact ? &koact : NULL, _NSIG / 8);
  if (result >= 0 || errno != ENOSYS)
    {
      if (oact && result >= 0)
	{
	  oact->sa_handler = koact.k_sa_handler;
	  memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
	  oact->sa_flags = koact.sa_flags;
#ifdef HAVE_SA_RESTORER
	  oact->sa_restorer = koact.sa_restorer;
#endif
	}
    }
  return result;
}
libc_hidden_def (__libc_sigaction)

#ifdef WRAPPER_INCLUDE
# include WRAPPER_INCLUDE
#endif

#ifndef LIBC_SIGACTION
weak_alias (__libc_sigaction, __sigaction)
libc_hidden_weak (__sigaction)
weak_alias (__libc_sigaction, sigaction)
#endif