sysdeps/unix/sysv/linux/signalfd.c

   1 /* Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <signal.h>
  21 #include <sys/signalfd.h>
  22 #include <sysdep.h>
  23 #include <kernel-features.h>
  24
  25
  26 int
  27 signalfd (int fd, const sigset_t *mask, int flags)
  28 {
  29 #ifdef __NR_signalfd4
  30   int res = INLINE_SYSCALL (signalfd4, 4, fd, mask, _NSIG / 8, flags);
  31 # ifndef __ASSUME_SIGNALFD4
  32   if (res != -1 || errno != ENOSYS)
  33 # endif
  34     return res;
  35 #endif
  36
  37 #ifndef __ASSUME_SIGNALFD4
  38   /* The old system call has no flag parameter which is bad.  So we have
  39      to wait until we have to support to pass additional values to the
  40      kernel (sys_indirect) before implementing setting flags like
  41      O_NONBLOCK etc.  */
  42   if (flags != 0)
  43     {
  44       __set_errno (EINVAL);
  45       return -1;
  46     }
  47
  48 # ifdef __NR_signalfd
  49   return INLINE_SYSCALL (signalfd, 3, fd, mask, _NSIG / 8);
  50 # else
  51   __set_errno (ENOSYS);
  52   return -1;
  53 # endif
  54 #elif !defined __NR_signalfd4
  55 # error "__ASSUME_SIGNALFD4 defined but not __NR_signalfd4"
  56 #endif
  57 }