1/*
2 * Access to user system call parameters and results
3 *
4 *  Copyright IBM Corp. 2008
5 *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License (version 2 only)
9 * as published by the Free Software Foundation.
10 */
11
12#ifndef _ASM_SYSCALL_H
13#define _ASM_SYSCALL_H	1
14
15#include <uapi/linux/audit.h>
16#include <linux/sched.h>
17#include <linux/err.h>
18#include <asm/ptrace.h>
19
20/*
21 * The syscall table always contains 32 bit pointers since we know that the
22 * address of the function to be called is (way) below 4GB.  So the "int"
23 * type here is what we want [need] for both 32 bit and 64 bit systems.
24 */
25extern const unsigned int sys_call_table[];
26extern const unsigned int sys_call_table_emu[];
27
28static inline long syscall_get_nr(struct task_struct *task,
29				  struct pt_regs *regs)
30{
31	return test_pt_regs_flag(regs, PIF_SYSCALL) ?
32		(regs->int_code & 0xffff) : -1;
33}
34
35static inline void syscall_rollback(struct task_struct *task,
36				    struct pt_regs *regs)
37{
38	regs->gprs[2] = regs->orig_gpr2;
39}
40
41static inline long syscall_get_error(struct task_struct *task,
42				     struct pt_regs *regs)
43{
44	return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 0;
45}
46
47static inline long syscall_get_return_value(struct task_struct *task,
48					    struct pt_regs *regs)
49{
50	return regs->gprs[2];
51}
52
53static inline void syscall_set_return_value(struct task_struct *task,
54					    struct pt_regs *regs,
55					    int error, long val)
56{
57	regs->gprs[2] = error ? error : val;
58}
59
60static inline void syscall_get_arguments(struct task_struct *task,
61					 struct pt_regs *regs,
62					 unsigned int i, unsigned int n,
63					 unsigned long *args)
64{
65	unsigned long mask = -1UL;
66
67	BUG_ON(i + n > 6);
68#ifdef CONFIG_COMPAT
69	if (test_tsk_thread_flag(task, TIF_31BIT))
70		mask = 0xffffffff;
71#endif
72	while (n-- > 0)
73		if (i + n > 0)
74			args[n] = regs->gprs[2 + i + n] & mask;
75	if (i == 0)
76		args[0] = regs->orig_gpr2 & mask;
77}
78
79static inline void syscall_set_arguments(struct task_struct *task,
80					 struct pt_regs *regs,
81					 unsigned int i, unsigned int n,
82					 const unsigned long *args)
83{
84	BUG_ON(i + n > 6);
85	while (n-- > 0)
86		if (i + n > 0)
87			regs->gprs[2 + i + n] = args[n];
88	if (i == 0)
89		regs->orig_gpr2 = args[0];
90}
91
92static inline int syscall_get_arch(void)
93{
94#ifdef CONFIG_COMPAT
95	if (test_tsk_thread_flag(current, TIF_31BIT))
96		return AUDIT_ARCH_S390;
97#endif
98	return sizeof(long) == 8 ? AUDIT_ARCH_S390X : AUDIT_ARCH_S390;
99}
100#endif	/* _ASM_SYSCALL_H */
101