sysdeps/unix/sysv/linux/sigwaitinfo.c

   1 /* Copyright (C) 1997-2016 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 #define __need_NULL
  21 #include <stddef.h>
  22 #include <string.h>
  23
  24 #include <nptl/pthreadP.h>
  25 #include <sysdep-cancel.h>
  26 #include <sys/syscall.h>
  27
  28 #ifdef __NR_rt_sigtimedwait
  29
  30 /* Return any pending signal or wait for one for the given time.  */
  31 int
  32 __sigwaitinfo (const sigset_t *set, siginfo_t *info)
  33 {
  34 #ifdef SIGCANCEL
  35   sigset_t tmpset;
  36   if (set != NULL
  37       && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
  38 # ifdef SIGSETXID
  39           || __builtin_expect (__sigismember (set, SIGSETXID), 0)
  40 # endif
  41           ))
  42     {
  43       /* Create a temporary mask without the bit for SIGCANCEL set.  */
  44       // We are not copying more than we have to.
  45       memcpy (&tmpset, set, _NSIG / 8);
  46       __sigdelset (&tmpset, SIGCANCEL);
  47 # ifdef SIGSETXID
  48       __sigdelset (&tmpset, SIGSETXID);
  49 # endif
  50       set = &tmpset;
  51     }
  52 #endif
  53
  54   /* XXX The size argument hopefully will have to be changed to the
  55      real size of the user-level sigset_t.  */
  56   int result = SYSCALL_CANCEL (rt_sigtimedwait, set, info, NULL, _NSIG / 8);
  57
  58   /* The kernel generates a SI_TKILL code in si_code in case tkill is
  59      used.  tkill is transparently used in raise().  Since having
  60      SI_TKILL as a code is useful in general we fold the results
  61      here.  */
  62   if (result != -1 && info != NULL && info->si_code == SI_TKILL)
  63     info->si_code = SI_USER;
  64
  65   return result;
  66 }
  67
  68 libc_hidden_def (__sigwaitinfo)
  69 weak_alias (__sigwaitinfo, sigwaitinfo)
  70 #else
  71 # include <signal/sigwaitinfo.c>
  72 #endif
  73 strong_alias (__sigwaitinfo, __libc_sigwaitinfo)