sysdeps/unix/sysv/linux/sysdep.h

   1 /* Copyright (C) 2015-2018 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <bits/wordsize.h>
  19 #include <kernel-features.h>
  20
  21 /* Set error number and return -1.  A target may choose to return the
  22    internal function, __syscall_error, which sets errno and returns -1.
  23    We use -1l, instead of -1, so that it can be casted to (void *).  */
  24 #define INLINE_SYSCALL_ERROR_RETURN_VALUE(err)  \
  25   ({                                            \
  26     __set_errno (err);                          \
  27     -1l;                                        \
  28   })
  29
  30 /* Provide a dummy argument that can be used to force register
  31    alignment for register pairs if required by the syscall ABI.  */
  32 #ifdef __ASSUME_ALIGNED_REGISTER_PAIRS
  33 #define __ALIGNMENT_ARG 0,
  34 #define __ALIGNMENT_COUNT(a,b) b
  35 #else
  36 #define __ALIGNMENT_ARG
  37 #define __ALIGNMENT_COUNT(a,b) a
  38 #endif
  39
  40 /* Provide a common macro to pass 64-bit value on syscalls.  */
  41 #if __WORDSIZE == 64 || defined __ASSUME_WORDSIZE64_ILP32
  42 # define SYSCALL_LL(val)   (val)
  43 # define SYSCALL_LL64(val) (val)
  44 #else
  45 #define SYSCALL_LL(val)   \
  46   __LONG_LONG_PAIR ((val) >> 31, (val))
  47 #define SYSCALL_LL64(val) \
  48   __LONG_LONG_PAIR ((long) ((val) >> 32), (long) ((val) & 0xffffffff))
  49 #endif
  50
  51 /* Provide a common macro to pass 64-bit value on pread and pwrite
  52    syscalls.  */
  53 #ifdef __ASSUME_PRW_DUMMY_ARG
  54 # define SYSCALL_LL_PRW(val)   0, SYSCALL_LL (val)
  55 # define SYSCALL_LL64_PRW(val) 0, SYSCALL_LL64 (val)
  56 #else
  57 # define SYSCALL_LL_PRW(val)   __ALIGNMENT_ARG SYSCALL_LL (val)
  58 # define SYSCALL_LL64_PRW(val) __ALIGNMENT_ARG SYSCALL_LL64 (val)
  59 #endif
  60
  61 /* Provide a macro to pass the off{64}_t argument on p{readv,writev}{64}.  */
  62 #define LO_HI_LONG(val) \
  63  (long) (val), \
  64  (long) (((uint64_t) (val)) >> 32)
  65
  66 /* Exports the __send symbol on send.c linux implementation (some ABI have
  67    it missing due the usage of a old generic version without it).  */
  68 #define HAVE_INTERNAL_SEND_SYMBOL       1