sysdeps/unix/sysv/linux/sh/pwrite.c

   1 /* Copyright (C) 1997, 1998, 2000, 2002, 2003, 2004, 2006
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    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 <unistd.h>
  23 #include <endian.h>
  24
  25 #include <sysdep-cancel.h>
  26 #include <sys/syscall.h>
  27 #include <bp-checks.h>
  28
  29 #include <kernel-features.h>
  30
  31 #ifdef __NR_pwrite64            /* Newer kernels renamed but it's the same.  */
  32 # ifdef __NR_pwrite
  33 #  error "__NR_pwrite and __NR_pwrite64 both defined???"
  34 # endif
  35 # define __NR_pwrite __NR_pwrite64
  36 #endif
  37
  38 #if defined __NR_pwrite || __ASSUME_PWRITE_SYSCALL > 0
  39
  40 # if __ASSUME_PWRITE_SYSCALL == 0
  41 static ssize_t __emulate_pwrite (int fd, const void *buf, size_t count,
  42                                  off_t offset) internal_function;
  43 # endif
  44
  45 ssize_t
  46 __libc_pwrite (fd, buf, count, offset)
  47      int fd;
  48      const void *buf;
  49      size_t count;
  50      off_t offset;
  51 {
  52   ssize_t result;
  53
  54   if (SINGLE_THREAD_P)
  55     {
  56       /* First try the syscall.  */
  57       result = INLINE_SYSCALL (pwrite, 6, fd, CHECK_N (buf, count), count, 0,
  58                                __LONG_LONG_PAIR (offset >> 31, offset));
  59 # if __ASSUME_PWRITE_SYSCALL == 0
  60       if (result == -1 && errno == ENOSYS)
  61         /* No system call available.  Use the emulation.  */
  62         result = __emulate_pwrite (fd, buf, count, offset);
  63 # endif
  64       return result;
  65     }
  66
  67   int oldtype = LIBC_CANCEL_ASYNC ();
  68
  69   /* First try the syscall.  */
  70   result = INLINE_SYSCALL (pwrite, 6, fd, CHECK_N (buf, count), count, 0,
  71                            __LONG_LONG_PAIR (offset >> 31, offset));
  72 # if __ASSUME_PWRITE_SYSCALL == 0
  73   if (result == -1 && errno == ENOSYS)
  74     /* No system call available.  Use the emulation.  */
  75     result = __emulate_pwrite (fd, buf, count, offset);
  76 # endif
  77
  78   LIBC_CANCEL_RESET (oldtype);
  79
  80   return result;
  81 }
  82
  83 strong_alias (__libc_pwrite, __pwrite)
  84 weak_alias (__libc_pwrite, pwrite)
  85
  86 # define __libc_pwrite(fd, buf, count, offset) \
  87      static internal_function __emulate_pwrite (fd, buf, count, offset)
  88 #endif
  89
  90 #if __ASSUME_PWRITE_SYSCALL == 0
  91 # include <sysdeps/posix/pwrite.c>
  92 #endif