sysdeps/unix/sysv/linux/pwrite64.c

   1 /* Copyright (C) 1997-2015 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 #ifdef __NR_pwrite64            /* Newer kernels renamed but it's the same.  */
  27 # ifdef __NR_pwrite
  28 #  error "__NR_pwrite and __NR_pwrite64 both defined???"
  29 # endif
  30 # define __NR_pwrite __NR_pwrite64
  31 #endif
  32
  33
  34 static ssize_t
  35 do_pwrite64 (int fd, const void *buf, size_t count, off64_t offset)
  36 {
  37   ssize_t result;
  38
  39   result = INLINE_SYSCALL (pwrite, 5, fd, buf, count,
  40                            __LONG_LONG_PAIR ((off_t) (offset >> 32),
  41                                              (off_t) (offset & 0xffffffff)));
  42
  43   return result;
  44 }
  45
  46
  47 ssize_t
  48 __libc_pwrite64 (fd, buf, count, offset)
  49      int fd;
  50      const void *buf;
  51      size_t count;
  52      off64_t offset;
  53 {
  54   if (SINGLE_THREAD_P)
  55     return do_pwrite64 (fd, buf, count, offset);
  56
  57   int oldtype = LIBC_CANCEL_ASYNC ();
  58
  59   ssize_t result = do_pwrite64 (fd, buf, count, offset);
  60
  61   LIBC_CANCEL_RESET (oldtype);
  62
  63   return result;
  64 }
  65
  66 weak_alias (__libc_pwrite64, __pwrite64)
  67 libc_hidden_weak (__pwrite64)
  68 weak_alias (__libc_pwrite64, pwrite64)