sysdeps/unix/sysv/linux/sigtimedwait.c

   1 /* Copyright (C) 1997-2017 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 <nptl/pthreadP.h>
  23 #include <sysdep-cancel.h>
  24 #include <sys/syscall.h>
  25
  26 #ifdef __NR_rt_sigtimedwait
  27
  28 int
  29 __sigtimedwait (const sigset_t *set, siginfo_t *info,
  30                 const struct timespec *timeout)
  31 {
  32 #ifdef SIGCANCEL
  33   sigset_t tmpset;
  34   if (set != NULL
  35       && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
  36 # ifdef SIGSETXID
  37           || __builtin_expect (__sigismember (set, SIGSETXID), 0)
  38 # endif
  39           ))
  40     {
  41       /* Create a temporary mask without the bit for SIGCANCEL set.  */
  42       // We are not copying more than we have to.
  43       memcpy (&tmpset, set, _NSIG / 8);
  44       __sigdelset (&tmpset, SIGCANCEL);
  45 # ifdef SIGSETXID
  46       __sigdelset (&tmpset, SIGSETXID);
  47 # endif
  48       set = &tmpset;
  49     }
  50 #endif
  51
  52     /* XXX The size argument hopefully will have to be changed to the
  53        real size of the user-level sigset_t.  */
  54   int result = SYSCALL_CANCEL (rt_sigtimedwait, set, 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 libc_hidden_def (__sigtimedwait)
  66 weak_alias (__sigtimedwait, sigtimedwait)
  67 #else
  68 # include <signal/sigtimedwait.c>
  69 #endif