/*
* Access to user system call parameters and results
*
* Copyright IBM Corp. 2008
* Author(s): Martin Schwidefsky ([email protected])
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (version 2 only)
* as published by the Free Software Foundation.
*/

#ifndef _ASM_SYSCALL_H
#define _ASM_SYSCALL_H 1

#include <linux/audit.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <asm/ptrace.h>

/*
* The syscall table always contains 32 bit pointers since we know that the
* address of the function to be called is (way) below 4GB. So the "int"
* type here is what we want [need] for both 32 bit and 64 bit systems.
*/
extern const unsigned int sys_call_table[];
extern const unsigned int sys_call_table_emu[];

static inline long syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
return test_tsk_thread_flag(task, TIF_SYSCALL) ?
(regs->int_code & 0xffff) : -1;
}

static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
regs->gprs[2] = regs->orig_gpr2;
}

static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 0;
}

static inline long syscall_get_return_value(struct task_struct *task,
struct pt_regs *regs)
{
return regs->gprs[2];
}

static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
regs->gprs[2] = error ? -error : val;
}

static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
unsigned long *args)
{
unsigned long mask = -1UL;

BUG_ON(i + n > 6);
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_31BIT))
mask = 0xffffffff;
#endif
while (n-- > 0)
if (i + n > 0)
args[n] = regs->gprs[2 + i + n] & mask;
if (i == 0)
args[0] = regs->orig_gpr2 & mask;
}

static inline void syscall_set_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
const unsigned long *args)
{
BUG_ON(i + n > 6);
while (n-- > 0)
if (i + n > 0)
regs->gprs[2 + i + n] = args[n];
if (i == 0)
regs->orig_gpr2 = args[0];
}

static inline int syscall_get_arch(struct task_struct *task,
struct pt_regs *regs)
{
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_31BIT))
return AUDIT_ARCH_S390;
#endif
return sizeof(long) == 8 ? AUDIT_ARCH_S390X : AUDIT_ARCH_S390;
}
#endif /* _ASM_SYSCALL_H */