glibc/sysdeps/unix/sysv/linux/sigprocmask.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>	/* Neede for string function builtin redirection.  */
#include <unistd.h>

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

#include <kernel-features.h>


/* Get and/or change the set of blocked signals.  */
int
__sigprocmask (how, set, oset)
     int how;
     const sigset_t *set;
     sigset_t *oset;
{
#ifdef SIGCANCEL
  sigset_t local_newmask;

  /* The only thing we have to make sure here is that SIGCANCEL and
     SIGSETXID are not blocked.  */
  if (set != NULL
      && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
# ifdef SIGSETXID
	  || __builtin_expect (__sigismember (set, SIGSETXID), 0)
# endif
	  ))
    {
      local_newmask = *set;
      __sigdelset (&local_newmask, SIGCANCEL);
# ifdef SIGSETXID
      __sigdelset (&local_newmask, SIGSETXID);
# endif
      set = &local_newmask;
    }
#endif

  return INLINE_SYSCALL (rt_sigprocmask, 4, how, set, oset, _NSIG / 8);
}
weak_alias (__sigprocmask, sigprocmask)