sysdeps/unix/sysv/linux/sigprocmask.c

   1 /* Copyright (C) 1997, 1998, 1999, 2000 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <errno.h>
  20 #include <signal.h>
  21 #include <unistd.h>
  22
  23 #include <sysdep.h>
  24 #include <sys/syscall.h>
  25 #include <bp-checks.h>
  26
  27 #include "kernel-features.h"
  28
  29
  30 extern int __syscall_sigprocmask (int, const sigset_t *__unbounded,
  31                                   sigset_t *__unbounded);
  32 extern int __syscall_rt_sigprocmask (int, const sigset_t *__unbounded,
  33                                      sigset_t *__unbounded, size_t);
  34
  35 /* The variable is shared between all wrappers around signal handling
  36    functions which have RT equivalents.  The definition is in sigaction.c.  */
  37 extern int __libc_missing_rt_sigs;
  38
  39
  40 /* Get and/or change the set of blocked signals.  */
  41 int
  42 __sigprocmask (how, set, oset)
  43      int how;
  44      const sigset_t *set;
  45      sigset_t *oset;
  46 {
  47 #if __ASSUME_REALTIME_SIGNALS > 0
  48   return INLINE_SYSCALL (rt_sigprocmask, 4, how, CHECK_SIGSET (set),
  49                          CHECK_SIGSET_NULL_OK (oset), _NSIG / 8);
  50 #else
  51 # ifdef __NR_rt_sigprocmask
  52   /* First try the RT signals.  */
  53   if (!__libc_missing_rt_sigs)
  54     {
  55       /* XXX The size argument hopefully will have to be changed to the
  56          real size of the user-level sigset_t.  */
  57       int saved_errno = errno;
  58       int result = INLINE_SYSCALL (rt_sigprocmask, 4, how, CHECK_SIGSET (set),
  59                                    CHECK_SIGSET_NULL_OK (oset), _NSIG / 8);
  60
  61       if (result >= 0 || errno != ENOSYS)
  62         return result;
  63
  64       __set_errno (saved_errno);
  65       __libc_missing_rt_sigs = 1;
  66     }
  67 # endif
  68
  69   return INLINE_SYSCALL (sigprocmask, 3, how,
  70                          CHECK_SIGSET (set), CHECK_SIGSET_NULL_OK (oset));
  71 #endif
  72 }
  73 weak_alias (__sigprocmask, sigprocmask)