sysdeps/unix/sysv/linux/sigwait.c

   1 /* Copyright (C) 1997,1998,2000,2002-2004,2005 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 <sysdep-cancel.h>
  25 #include <sys/syscall.h>
  26 #include <bp-checks.h>
  27
  28 #ifdef __NR_rt_sigtimedwait
  29
  30 /* Return any pending signal or wait for one for the given time.  */
  31 static int
  32 do_sigwait (const sigset_t *set, int *sig)
  33 {
  34   int ret;
  35
  36 #ifdef SIGCANCEL
  37   sigset_t tmpset;
  38   if (set != NULL
  39       && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
  40 # ifdef SIGSETXID
  41           || __builtin_expect (__sigismember (set, SIGSETXID), 0)
  42 # endif
  43           ))
  44     {
  45       /* Create a temporary mask without the bit for SIGCANCEL set.  */
  46       // We are not copying more than we have to.
  47       memcpy (&tmpset, set, _NSIG / 8);
  48       __sigdelset (&tmpset, SIGCANCEL);
  49 # ifdef SIGSETXID
  50       __sigdelset (&tmpset, SIGSETXID);
  51 # endif
  52       set = &tmpset;
  53     }
  54 #endif
  55
  56   /* XXX The size argument hopefully will have to be changed to the
  57      real size of the user-level sigset_t.  */
  58 #ifdef INTERNAL_SYSCALL
  59   INTERNAL_SYSCALL_DECL (err);
  60   do
  61     ret = INTERNAL_SYSCALL (rt_sigtimedwait, err, 4, CHECK_SIGSET (set),
  62                             NULL, NULL, _NSIG / 8);
  63   while (INTERNAL_SYSCALL_ERROR_P (ret, err)
  64          && INTERNAL_SYSCALL_ERRNO (ret, err) == EINTR);
  65   if (! INTERNAL_SYSCALL_ERROR_P (ret, err))
  66     {
  67       *sig = ret;
  68       ret = 0;
  69     }
  70   else
  71     ret = INTERNAL_SYSCALL_ERRNO (ret, err);
  72 #else
  73   do
  74     ret = INLINE_SYSCALL (rt_sigtimedwait, 4, CHECK_SIGSET (set),
  75                           NULL, NULL, _NSIG / 8);
  76   while (ret == -1 && errno == EINTR);
  77   if (ret != -1)
  78     {
  79       *sig = ret;
  80       ret = 0;
  81     }
  82   else
  83     ret = errno;
  84 #endif
  85
  86   return ret;
  87 }
  88
  89 int
  90 __sigwait (set, sig)
  91      const sigset_t *set;
  92      int *sig;
  93 {
  94   if (SINGLE_THREAD_P)
  95     return do_sigwait (set, sig);
  96
  97   int oldtype = LIBC_CANCEL_ASYNC ();
  98
  99   int result = do_sigwait (set, sig);
 100
 101   LIBC_CANCEL_RESET (oldtype);
 102
 103   return result;
 104 }
 105 libc_hidden_def (__sigwait)
 106 weak_alias (__sigwait, sigwait)
 107 #else
 108 # include <sysdeps/posix/sigwait.c>
 109 #endif
 110 strong_alias (__sigwait, __libc_sigwait)