sysdeps/unix/sysv/linux/sigtimedwait.c

   1 /* Copyright (C) 1997-2014 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <signal.h>
  20 #include <string.h>
  21
  22 #include <sysdep-cancel.h>
  23 #include <sys/syscall.h>
  24
  25 #ifdef __NR_rt_sigtimedwait
  26
  27 static int
  28 do_sigtimedwait (const sigset_t *set, siginfo_t *info,
  29                  const struct timespec *timeout)
  30 {
  31 #ifdef SIGCANCEL
  32   sigset_t tmpset;
  33   if (set != NULL
  34       && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
  35 # ifdef SIGSETXID
  36           || __builtin_expect (__sigismember (set, SIGSETXID), 0)
  37 # endif
  38           ))
  39     {
  40       /* Create a temporary mask without the bit for SIGCANCEL set.  */
  41       // We are not copying more than we have to.
  42       memcpy (&tmpset, set, _NSIG / 8);
  43       __sigdelset (&tmpset, SIGCANCEL);
  44 # ifdef SIGSETXID
  45       __sigdelset (&tmpset, SIGSETXID);
  46 # endif
  47       set = &tmpset;
  48     }
  49 #endif
  50
  51     /* XXX The size argument hopefully will have to be changed to the
  52        real size of the user-level sigset_t.  */
  53   int result = INLINE_SYSCALL (rt_sigtimedwait, 4, set,
  54                                info, timeout, _NSIG / 8);
  55
  56   /* The kernel generates a SI_TKILL code in si_code in case tkill is
  57      used.  tkill is transparently used in raise().  Since having
  58      SI_TKILL as a code is useful in general we fold the results
  59      here.  */
  60   if (result != -1 && info != NULL && info->si_code == SI_TKILL)
  61     info->si_code = SI_USER;
  62
  63   return result;
  64 }
  65
  66
  67 /* Return any pending signal or wait for one for the given time.  */
  68 int
  69 __sigtimedwait (set, info, timeout)
  70      const sigset_t *set;
  71      siginfo_t *info;
  72      const struct timespec *timeout;
  73 {
  74   if (SINGLE_THREAD_P)
  75     return do_sigtimedwait (set, info, timeout);
  76
  77   int oldtype = LIBC_CANCEL_ASYNC ();
  78
  79   /* XXX The size argument hopefully will have to be changed to the
  80      real size of the user-level sigset_t.  */
  81   int result = do_sigtimedwait (set, info, timeout);
  82
  83   LIBC_CANCEL_RESET (oldtype);
  84
  85   return result;
  86 }
  87 libc_hidden_def (__sigtimedwait)
  88 weak_alias (__sigtimedwait, sigtimedwait)
  89 #else
  90 # include <signal/sigtimedwait.c>
  91 #endif