ports/sysdeps/unix/sysv/linux/arm/pread.c

   1 /* Copyright (C) 1997-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <endian.h>
  21 #include <unistd.h>
  22
  23 #include <sysdep-cancel.h>
  24 #include <sys/syscall.h>
  25
  26 ssize_t
  27 __libc_pread (fd, buf, count, offset)
  28      int fd;
  29      void *buf;
  30      size_t count;
  31      off_t offset;
  32 {
  33   ssize_t result;
  34
  35   if (SINGLE_THREAD_P)
  36     {
  37       /* In the ARM EABI, 64-bit values are aligned to even/odd register
  38          pairs for syscalls.  */
  39       result = INLINE_SYSCALL (pread64, 6, fd, buf, count, 0,
  40                                __LONG_LONG_PAIR (offset >> 31, offset));
  41
  42       return result;
  43     }
  44
  45   int oldtype = LIBC_CANCEL_ASYNC ();
  46
  47   /* In the ARM EABI, 64-bit values are aligned to even/odd register
  48      pairs for syscalls.  */
  49   result = INLINE_SYSCALL (pread64, 6, fd, buf, count, 0,
  50                            __LONG_LONG_PAIR (offset >> 31, offset));
  51
  52   LIBC_CANCEL_RESET (oldtype);
  53
  54   return result;
  55 }
  56
  57 strong_alias (__libc_pread, __pread)
  58 weak_alias (__libc_pread, pread)