https://github.com/torvalds/linux
Tip revision: 08895a8b6b06ed2323cd97a36ee40a116b3db8ed authored by Linus Torvalds on 26 September 2016, 01:47:13 UTC
Linux 4.8-rc8
Linux 4.8-rc8
Tip revision: 08895a8
syscall.h
/*
* Access to user system call parameters and results
*
* Copyright (C) 2008 Imagination Technologies Ltd.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*
* See asm-generic/syscall.h for descriptions of what we must do here.
*/
#ifndef _ASM_METAG_SYSCALL_H
#define _ASM_METAG_SYSCALL_H
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/uaccess.h>
#include <asm/switch.h>
static inline long syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
unsigned long insn;
/*
* FIXME there's no way to find out how we got here other than to
* examine the memory at the PC to see if it is a syscall
* SWITCH instruction.
*/
if (get_user(insn, (unsigned long *)(regs->ctx.CurrPC - 4)))
return -1;
if (insn == __METAG_SW_ENCODING(SYS))
return regs->ctx.DX[0].U1;
else
return -1L;
}
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
/* do nothing */
}
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
unsigned long error = regs->ctx.DX[0].U0;
return IS_ERR_VALUE(error) ? error : 0;
}
static inline long syscall_get_return_value(struct task_struct *task,
struct pt_regs *regs)
{
return regs->ctx.DX[0].U0;
}
static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
regs->ctx.DX[0].U0 = (long) 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 int reg, j;
BUG_ON(i + n > 6);
for (j = i, reg = 6 - i; j < (i + n); j++, reg--) {
if (reg % 2)
args[j] = regs->ctx.DX[(reg + 1) / 2].U0;
else
args[j] = regs->ctx.DX[reg / 2].U1;
}
}
static inline void syscall_set_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
const unsigned long *args)
{
unsigned int reg;
BUG_ON(i + n > 6);
for (reg = 6 - i; i < (i + n); i++, reg--) {
if (reg % 2)
regs->ctx.DX[(reg + 1) / 2].U0 = args[i];
else
regs->ctx.DX[reg / 2].U1 = args[i];
}
}
#define NR_syscalls __NR_syscalls
/* generic syscall table */
extern const void *sys_call_table[];
#endif /* _ASM_METAG_SYSCALL_H */