1/* Copyright (C) 2015-2020 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 <errno.h>
24
25#undef INTERNAL_SYSCALL_ERROR_P
26#define INTERNAL_SYSCALL_ERROR_P(val) \
27 ((unsigned long int) (val) > -4096UL)
28
29#ifndef SYSCALL_ERROR_LABEL
30# define SYSCALL_ERROR_LABEL(sc_err) \
31 ({ \
32 __set_errno (sc_err); \
33 -1L; \
34 })
35#endif
36
37/* Define a macro which expands into the inline wrapper code for a system
38 call. It sets the errno and returns -1 on a failure, or the syscall
39 return value otherwise. */
40#undef INLINE_SYSCALL
41#define INLINE_SYSCALL(name, nr, args...) \
42 ({ \
43 long int sc_ret = INTERNAL_SYSCALL (name, nr, args); \
44 __glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (sc_ret)) \
45 ? SYSCALL_ERROR_LABEL (INTERNAL_SYSCALL_ERRNO (sc_ret)) \
46 : sc_ret; \
47 })
48
49#undef INTERNAL_SYSCALL_ERRNO
50#define INTERNAL_SYSCALL_ERRNO(val) (-(val))
51
52/* Set error number and return -1. A target may choose to return the
53 internal function, __syscall_error, which sets errno and returns -1.
54 We use -1l, instead of -1, so that it can be casted to (void *). */
55#define INLINE_SYSCALL_ERROR_RETURN_VALUE(err) \
56 ({ \
57 __set_errno (err); \
58 -1l; \
59 })
60
61/* Provide a dummy argument that can be used to force register
62 alignment for register pairs if required by the syscall ABI. */
63#ifdef __ASSUME_ALIGNED_REGISTER_PAIRS
64#define __ALIGNMENT_ARG 0,
65#define __ALIGNMENT_COUNT(a,b) b
66#else
67#define __ALIGNMENT_ARG
68#define __ALIGNMENT_COUNT(a,b) a
69#endif
70
71/* Provide a common macro to pass 64-bit value on syscalls. */
72#if __WORDSIZE == 64 || defined __ASSUME_WORDSIZE64_ILP32
73# define SYSCALL_LL(val) (val)
74# define SYSCALL_LL64(val) (val)
75#else
76#define SYSCALL_LL(val) \
77 __LONG_LONG_PAIR ((val) >> 31, (val))
78#define SYSCALL_LL64(val) \
79 __LONG_LONG_PAIR ((long) ((val) >> 32), (long) ((val) & 0xffffffff))
80#endif
81
82/* Provide a common macro to pass 64-bit value on pread and pwrite
83 syscalls. */
84#ifdef __ASSUME_PRW_DUMMY_ARG
85# define SYSCALL_LL_PRW(val) 0, SYSCALL_LL (val)
86# define SYSCALL_LL64_PRW(val) 0, SYSCALL_LL64 (val)
87#else
88# define SYSCALL_LL_PRW(val) __ALIGNMENT_ARG SYSCALL_LL (val)
89# define SYSCALL_LL64_PRW(val) __ALIGNMENT_ARG SYSCALL_LL64 (val)
90#endif
91
92/* Provide a macro to pass the off{64}_t argument on p{readv,writev}{64}. */
93#define LO_HI_LONG(val) \
94 (long) (val), \
95 (long) (((uint64_t) (val)) >> 32)
96
97/* Exports the __send symbol on send.c linux implementation (some ABI have
98 it missing due the usage of a old generic version without it). */
99#define HAVE_INTERNAL_SEND_SYMBOL 1
100
101#endif /* _SYSDEP_LINUX_H */
102