sysdeps/unix/sysv/linux/pwrite64.c

   1 /* Copyright (C) 1997, 1998, 1999, 2000 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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <errno.h>
  21 #include <endian.h>
  22 #include <unistd.h>
  23
  24 #include <sysdep.h>
  25 #include <sys/syscall.h>
  26 #include <bp-checks.h>
  27
  28 #include "kernel-features.h"
  29
  30 #if defined __NR_pwrite || __ASSUME_PWRITE_SYSCALL > 0
  31
  32 extern ssize_t __syscall_pwrite (int fd, const void *__unbounded buf, size_t count,
  33                                  off_t offset_hi, off_t offset_lo);
  34
  35 # if __ASSUME_PWRITE_SYSCALL == 0
  36 static ssize_t __emulate_pwrite64 (int fd, const void *buf, size_t count,
  37                                    off64_t offset) internal_function;
  38 # endif
  39
  40
  41 ssize_t
  42 __libc_pwrite64 (fd, buf, count, offset)
  43      int fd;
  44      const void *buf;
  45      size_t count;
  46      off64_t offset;
  47 {
  48   ssize_t result;
  49
  50   /* First try the syscall.  */
  51   result = INLINE_SYSCALL (pwrite, 5, fd, CHECK_N (buf, count), count,
  52                            __LONG_LONG_PAIR ((off_t) (offset >> 32),
  53                                              (off_t) (offset & 0xffffffff)));
  54 # if __ASSUME_PWRITE_SYSCALL == 0
  55   if (result == -1 && errno == ENOSYS)
  56     /* No system call available.  Use the emulation.  */
  57     result = __emulate_pwrite64 (fd, buf, count, offset);
  58 # endif
  59
  60   return result;
  61 }
  62
  63 weak_alias (__libc_pwrite64, __pwrite64)
  64 weak_alias (__libc_pwrite64, pwrite64)
  65
  66 # define __libc_pwrite64(fd, buf, count, offset) \
  67      static internal_function __emulate_pwrite64 (fd, buf, count, offset)
  68 #endif
  69
  70 #if __ASSUME_PWRITE_SYSCALL == 0
  71 # include <sysdeps/posix/pwrite64.c>
  72 #endif