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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Access to user system call parameters and results
4 *
5 * See asm-generic/syscall.h for descriptions of what we must do here.
6 */
7
8#ifndef _ASM_ARM_SYSCALL_H
9#define _ASM_ARM_SYSCALL_H
10
11#include <uapi/linux/audit.h> /* for AUDIT_ARCH_* */
12#include <linux/elf.h> /* for ELF_EM */
13#include <linux/err.h>
14#include <linux/sched.h>
15
16#include <asm/unistd.h>
17
18#define NR_syscalls (__NR_syscalls)
19
20extern const unsigned long sys_call_table[];
21
22static inline int syscall_get_nr(struct task_struct *task,
23 struct pt_regs *regs)
24{
25 return task_thread_info(task)->syscall;
26}
27
28static inline void syscall_rollback(struct task_struct *task,
29 struct pt_regs *regs)
30{
31 regs->ARM_r0 = regs->ARM_ORIG_r0;
32}
33
34static inline long syscall_get_error(struct task_struct *task,
35 struct pt_regs *regs)
36{
37 unsigned long error = regs->ARM_r0;
38 return IS_ERR_VALUE(error) ? error : 0;
39}
40
41static inline long syscall_get_return_value(struct task_struct *task,
42 struct pt_regs *regs)
43{
44 return regs->ARM_r0;
45}
46
47static inline void syscall_set_return_value(struct task_struct *task,
48 struct pt_regs *regs,
49 int error, long val)
50{
51 regs->ARM_r0 = (long) error ? error : val;
52}
53
54#define SYSCALL_MAX_ARGS 7
55
56static inline void syscall_get_arguments(struct task_struct *task,
57 struct pt_regs *regs,
58 unsigned int i, unsigned int n,
59 unsigned long *args)
60{
61 if (n == 0)
62 return;
63
64 if (i + n > SYSCALL_MAX_ARGS) {
65 unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
66 unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
67 pr_warn("%s called with max args %d, handling only %d\n",
68 __func__, i + n, SYSCALL_MAX_ARGS);
69 memset(args_bad, 0, n_bad * sizeof(args[0]));
70 n = SYSCALL_MAX_ARGS - i;
71 }
72
73 if (i == 0) {
74 args[0] = regs->ARM_ORIG_r0;
75 args++;
76 i++;
77 n--;
78 }
79
80 memcpy(args, ®s->ARM_r0 + i, n * sizeof(args[0]));
81}
82
83static inline void syscall_set_arguments(struct task_struct *task,
84 struct pt_regs *regs,
85 unsigned int i, unsigned int n,
86 const unsigned long *args)
87{
88 if (n == 0)
89 return;
90
91 if (i + n > SYSCALL_MAX_ARGS) {
92 pr_warn("%s called with max args %d, handling only %d\n",
93 __func__, i + n, SYSCALL_MAX_ARGS);
94 n = SYSCALL_MAX_ARGS - i;
95 }
96
97 if (i == 0) {
98 regs->ARM_ORIG_r0 = args[0];
99 args++;
100 i++;
101 n--;
102 }
103
104 memcpy(®s->ARM_r0 + i, args, n * sizeof(args[0]));
105}
106
107static inline int syscall_get_arch(void)
108{
109 /* ARM tasks don't change audit architectures on the fly. */
110 return AUDIT_ARCH_ARM;
111}
112
113#endif /* _ASM_ARM_SYSCALL_H */