1/* Copyright (C) 2015-2025 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   <https://www.gnu.org/licenses/>.  */
 17
 18#ifndef _SYSDEP_LINUX_H
 19#define _SYSDEP_LINUX_H
 20
 21#include <bits/wordsize.h>
 22#include <kernel-features.h>
 23#include <endian.h>
 24#include <errno.h>
 25
 26#undef INTERNAL_SYSCALL_ERROR_P
 27#define INTERNAL_SYSCALL_ERROR_P(val) \
 28  ((unsigned long int) (val) > -4096UL)
 29
 30#ifndef SYSCALL_ERROR_LABEL
 31# define SYSCALL_ERROR_LABEL(sc_err)					\
 32  ({									\
 33    __set_errno (sc_err);						\
 34    -1L;								\
 35  })
 36#endif
 37
 38/* Define a macro which expands into the inline wrapper code for a system
 39   call.  It sets the errno and returns -1 on a failure, or the syscall
 40   return value otherwise.  */
 41#undef INLINE_SYSCALL
 42#define INLINE_SYSCALL(name, nr, args...)				\
 43  ({									\
 44    long int sc_ret = INTERNAL_SYSCALL (name, nr, args);		\
 45    __glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (sc_ret))		\
 46    ? SYSCALL_ERROR_LABEL (INTERNAL_SYSCALL_ERRNO (sc_ret))		\
 47    : sc_ret;								\
 48  })
 49
 50#undef INTERNAL_SYSCALL_ERRNO
 51#define INTERNAL_SYSCALL_ERRNO(val)     (-(val))
 52
 53/* Set error number and return -1.  A target may choose to return the
 54   internal function, __syscall_error, which sets errno and returns -1.
 55   We use -1l, instead of -1, so that it can be casted to (void *).  */
 56#define INLINE_SYSCALL_ERROR_RETURN_VALUE(err)  \
 57  ({						\
 58    __set_errno (err);				\
 59    -1l;					\
 60  })
 61
 62/* Provide a dummy argument that can be used to force register
 63   alignment for register pairs if required by the syscall ABI.  */
 64#ifdef __ASSUME_ALIGNED_REGISTER_PAIRS
 65#define __ALIGNMENT_ARG 0,
 66#define __ALIGNMENT_COUNT(a,b) b
 67#else
 68#define __ALIGNMENT_ARG
 69#define __ALIGNMENT_COUNT(a,b) a
 70#endif
 71
 72/* Provide a common macro to pass 64-bit value on syscalls.  */
 73#if __WORDSIZE == 64 || defined __ASSUME_WORDSIZE64_ILP32
 74# define SYSCALL_LL(val)   (val)
 75# define SYSCALL_LL64(val) (val)
 76#else
 77#define SYSCALL_LL(val)   \
 78  __LONG_LONG_PAIR ((val) >> 31, (val))
 79#define SYSCALL_LL64(val) \
 80  __LONG_LONG_PAIR ((long) ((val) >> 32), (long) ((val) & 0xffffffff))
 81#endif
 82
 83/* Provide a common macro to pass 64-bit value on pread and pwrite
 84   syscalls.  */
 85#ifdef __ASSUME_PRW_DUMMY_ARG
 86# define SYSCALL_LL_PRW(val)   0, SYSCALL_LL (val)
 87# define SYSCALL_LL64_PRW(val) 0, SYSCALL_LL64 (val)
 88#else
 89# define SYSCALL_LL_PRW(val)   __ALIGNMENT_ARG SYSCALL_LL (val)
 90# define SYSCALL_LL64_PRW(val) __ALIGNMENT_ARG SYSCALL_LL64 (val)
 91#endif
 92
 93/* Provide a macro to pass the off{64}_t argument on p{readv,writev}{64}.  */
 94#define LO_HI_LONG(val) \
 95 (long) (val), \
 96 (long) (((uint64_t) (val)) >> 32)
 97
 98/* Export the ___brk_addr symbol on brk.c implementation (some ABIs export
 99   it due and old crtstuff.c code).  */
100#define HAVE_INTERNAL_BRK_ADDR_SYMBOL   0
101
102#endif /* _SYSDEP_LINUX_H  */