1/* Copyright (C) 2015-2021 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/* Exports the __send symbol on send.c linux implementation (some ABI have
99 it missing due the usage of a old generic version without it). */
100#define HAVE_INTERNAL_SEND_SYMBOL 1
101
102/* Export the ___brk_addr symbol on brk.c implementation (some ABIs export
103 it due and old crtstuff.c code). */
104#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 0
105
106#endif /* _SYSDEP_LINUX_H */
107