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
12 typedef long (*syscall_fn_t)(const struct pt_regs *regs);
13
14 extern const syscall_fn_t sys_call_table[];
15
16 #ifdef CONFIG_COMPAT
17 extern const syscall_fn_t compat_sys_call_table[];
18 #endif
19
syscall_get_nr(struct task_struct * task,struct pt_regs * regs)20 static inline int syscall_get_nr(struct task_struct *task,
21 struct pt_regs *regs)
22 {
23 return regs->syscallno;
24 }
25
syscall_rollback(struct task_struct * task,struct pt_regs * regs)26 static inline void syscall_rollback(struct task_struct *task,
27 struct pt_regs *regs)
28 {
29 regs->regs[0] = regs->orig_x0;
30 }
31
32
syscall_get_error(struct task_struct * task,struct pt_regs * regs)33 static 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
syscall_get_return_value(struct task_struct * task,struct pt_regs * regs)44 static inline long syscall_get_return_value(struct task_struct *task,
45 struct pt_regs *regs)
46 {
47 return regs->regs[0];
48 }
49
syscall_set_return_value(struct task_struct * task,struct pt_regs * regs,int error,long val)50 static 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
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned long * args)65 static 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
syscall_set_arguments(struct task_struct * task,struct pt_regs * regs,const unsigned long * args)75 static 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 */
syscall_get_arch(struct task_struct * task)89 static 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 */
98
