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
32static inline long syscall_get_return_value(struct task_struct *task,
33					    struct pt_regs *regs)
34{
35	unsigned long val = regs->regs[0];
36
37	if (is_compat_thread(task_thread_info(task)))
38		val = sign_extend64(val, 31);
39
40	return val;
41}
42
43static inline long syscall_get_error(struct task_struct *task,
44				     struct pt_regs *regs)
45{
46	unsigned long error = syscall_get_return_value(task, regs);
47
48	return IS_ERR_VALUE(error) ? error : 0;
49}
50
51static inline void syscall_set_return_value(struct task_struct *task,
52					    struct pt_regs *regs,
53					    int error, long val)
54{
55	if (error)
56		val = error;
57
58	if (is_compat_thread(task_thread_info(task)))
59		val = lower_32_bits(val);
60
61	regs->regs[0] = val;
62}
63
64#define SYSCALL_MAX_ARGS 6
65
66static inline void syscall_get_arguments(struct task_struct *task,
67					 struct pt_regs *regs,
68					 unsigned long *args)
69{
70	args[0] = regs->orig_x0;
71	args++;
72
73	memcpy(args, &regs->regs[1], 5 * sizeof(args[0]));
74}
75
76/*
77 * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
78 * AArch64 has the same system calls both on little- and big- endian.
79 */
80static inline int syscall_get_arch(struct task_struct *task)
81{
82	if (is_compat_thread(task_thread_info(task)))
83		return AUDIT_ARCH_ARM;
84
85	return AUDIT_ARCH_AARCH64;
86}
87
88int syscall_trace_enter(struct pt_regs *regs);
89void syscall_trace_exit(struct pt_regs *regs);
90
91#endif	/* __ASM_SYSCALL_H */
92