sysdeps/unix/sysv/linux/pselect.c

   1 /* Copyright (C) 2006-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2006.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <sys/select.h>
  20 #include <sysdep-cancel.h>
  21 #include <time64-support.h>
  22
  23 int
  24 __pselect64 (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
  25              const struct __timespec64 *timeout, const sigset_t *sigmask)
  26 {
  27   /* The Linux kernel can in some situations update the timeout value.
  28      We do not want that so use a local variable.  */
  29   struct __timespec64 tval;
  30   if (timeout != NULL)
  31     {
  32       tval = *timeout;
  33       timeout = &tval;
  34     }
  35
  36   /* Note: the system call expects 7 values but on most architectures
  37      we can only pass in 6 directly.  If there is an architecture with
  38      support for more parameters a new version of this file needs to
  39      be created.  */
  40
  41 #ifndef __NR_pselect6_time64
  42 # define __NR_pselect6_time64 __NR_pselect6
  43 #endif
  44   int r;
  45   if (supports_time64 ())
  46     {
  47       /* NB: This is required by ARGIFY used in x32 internal_syscallN.  */
  48       __syscall_ulong_t data[2] =
  49         {
  50           (uintptr_t) sigmask, __NSIG_BYTES
  51         };
  52       r = SYSCALL_CANCEL (pselect6_time64, nfds, readfds, writefds, exceptfds,
  53                           timeout, data);
  54       if (r == 0 || errno != ENOSYS)
  55         return r;
  56
  57       mark_time64_unsupported ();
  58     }
  59
  60 #ifndef __ASSUME_TIME64_SYSCALLS
  61   r = __pselect32 (nfds, readfds, writefds, exceptfds, timeout, sigmask);
  62 #endif
  63   return r;
  64 }
  65
  66 #if __TIMESIZE != 64
  67 libc_hidden_def (__pselect64)
  68
  69 int
  70 __pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
  71            const struct timespec *timeout, const sigset_t *sigmask)
  72 {
  73   struct __timespec64 ts64, *pts64 = NULL;
  74   if (timeout != NULL)
  75     {
  76       ts64 = valid_timespec_to_timespec64 (*timeout);
  77       pts64 = &ts64;
  78     }
  79   return __pselect64 (nfds, readfds, writefds, exceptfds, pts64, sigmask);
  80 }
  81 #endif
  82
  83 #ifndef __pselect
  84 weak_alias (__pselect, pselect)
  85 #endif