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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2012 ARM Ltd.
4 */
5#ifndef __ASM_SYSCALL_H
6#define __ASM_SYSCALL_H
7
8#include <uapi/linux/audit.h>
9#include <linux/compat.h>
10#include <linux/err.h>
11
12typedef long (*syscall_fn_t)(const struct pt_regs *regs);
13
14extern const syscall_fn_t sys_call_table[];
15
16#ifdef CONFIG_COMPAT
17extern const syscall_fn_t compat_sys_call_table[];
18#endif
19
20static inline int syscall_get_nr(struct task_struct *task,
21 struct pt_regs *regs)
22{
23 return regs->syscallno;
24}
25
26static inline void syscall_rollback(struct task_struct *task,
27 struct pt_regs *regs)
28{
29 regs->regs[0] = regs->orig_x0;
30}
31
32
33static inline long syscall_get_error(struct task_struct *task,
34 struct pt_regs *regs)
35{
36 unsigned long error = regs->regs[0];
37
38 if (is_compat_thread(task_thread_info(task)))
39 error = sign_extend64(error, 31);
40
41 return IS_ERR_VALUE(error) ? error : 0;
42}
43
44static inline long syscall_get_return_value(struct task_struct *task,
45 struct pt_regs *regs)
46{
47 return regs->regs[0];
48}
49
50static inline void syscall_set_return_value(struct task_struct *task,
51 struct pt_regs *regs,
52 int error, long val)
53{
54 if (error)
55 val = error;
56
57 if (is_compat_thread(task_thread_info(task)))
58 val = lower_32_bits(val);
59
60 regs->regs[0] = val;
61}
62
63#define SYSCALL_MAX_ARGS 6
64
65static inline void syscall_get_arguments(struct task_struct *task,
66 struct pt_regs *regs,
67 unsigned long *args)
68{
69 args[0] = regs->orig_x0;
70 args++;
71
72 memcpy(args, ®s->regs[1], 5 * sizeof(args[0]));
73}
74
75static inline void syscall_set_arguments(struct task_struct *task,
76 struct pt_regs *regs,
77 const unsigned long *args)
78{
79 regs->orig_x0 = args[0];
80 args++;
81
82 memcpy(®s->regs[1], args, 5 * sizeof(args[0]));
83}
84
85/*
86 * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
87 * AArch64 has the same system calls both on little- and big- endian.
88 */
89static inline int syscall_get_arch(struct task_struct *task)
90{
91 if (is_compat_thread(task_thread_info(task)))
92 return AUDIT_ARCH_ARM;
93
94 return AUDIT_ARCH_AARCH64;
95}
96
97#endif /* __ASM_SYSCALL_H */