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