sysdeps/unix/sysv/linux/generic/wordsize-32/pwrite.c

   1 /* Copyright (C) 2011-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
   4    Based on work contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library.  If not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22 #include <endian.h>
  23 #include <unistd.h>
  24
  25 #include <sysdep-cancel.h>
  26 #include <sys/syscall.h>
  27
  28 static ssize_t
  29 do_pwrite (int fd, const void *buf, size_t count, off_t offset)
  30 {
  31   assert (sizeof (offset) == 4);
  32   return INLINE_SYSCALL (pwrite64, __ALIGNMENT_COUNT (5, 6), fd,
  33                          buf, count, __ALIGNMENT_ARG
  34                          __LONG_LONG_PAIR (offset >> 31, offset));
  35 }
  36
  37
  38 ssize_t
  39 __libc_pwrite (fd, buf, count, offset)
  40      int fd;
  41      const void *buf;
  42      size_t count;
  43      off_t offset;
  44 {
  45   if (SINGLE_THREAD_P)
  46     return do_pwrite (fd, buf, count, offset);
  47
  48   int oldtype = LIBC_CANCEL_ASYNC ();
  49
  50   ssize_t result = do_pwrite (fd, buf, count, offset);
  51
  52   LIBC_CANCEL_RESET (oldtype);
  53
  54   return result;
  55 }
  56 strong_alias (__libc_pwrite, __pwrite)
  57 weak_alias (__libc_pwrite, pwrite)