352c1d95e3
Historically, pt_regs have had orig_r8, an overloaded container for (1) backup copy of r8 (syscall number Trap Exceptions) (2) additional system state: (syscall/Exception/Interrupt) There is no point in keeping (1) since syscall number is never clobbered in-place, in pt_regs, unlike r0 which duals as first syscall arg as well as syscall return value and in case of syscall restart, the orig arg0 needs restoring (from orig_r0) after having been updated in-place with syscall ret value. This further paves way to convert (2) to contain ECR itself (rather than current madeup values) Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
/*
|
|
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#ifndef _ASM_ARC_SYSCALL_H
|
|
#define _ASM_ARC_SYSCALL_H 1
|
|
|
|
#include <linux/err.h>
|
|
#include <linux/sched.h>
|
|
#include <asm/unistd.h>
|
|
#include <asm/ptrace.h> /* in_syscall() */
|
|
|
|
static inline long
|
|
syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
|
|
{
|
|
if (user_mode(regs) && in_syscall(regs))
|
|
return regs->r8;
|
|
else
|
|
return -1;
|
|
}
|
|
|
|
static inline void
|
|
syscall_rollback(struct task_struct *task, struct pt_regs *regs)
|
|
{
|
|
regs->r0 = regs->orig_r0;
|
|
}
|
|
|
|
static inline long
|
|
syscall_get_error(struct task_struct *task, struct pt_regs *regs)
|
|
{
|
|
/* 0 if syscall succeeded, otherwise -Errorcode */
|
|
return IS_ERR_VALUE(regs->r0) ? regs->r0 : 0;
|
|
}
|
|
|
|
static inline long
|
|
syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
|
|
{
|
|
return regs->r0;
|
|
}
|
|
|
|
static inline void
|
|
syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
|
|
int error, long val)
|
|
{
|
|
regs->r0 = (long) error ?: val;
|
|
}
|
|
|
|
/*
|
|
* @i: argument index [0,5]
|
|
* @n: number of arguments; n+i must be [1,6].
|
|
*/
|
|
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 *inside_ptregs = &(regs->r0);
|
|
inside_ptregs -= i;
|
|
|
|
BUG_ON((i + n) > 6);
|
|
|
|
while (n--) {
|
|
args[i++] = (*inside_ptregs);
|
|
inside_ptregs--;
|
|
}
|
|
}
|
|
|
|
#endif
|