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/*
* Access to user system call parameters and results
*
* Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
*
* 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_X86_SYSCALL_H
#define _ASM_X86_SYSCALL_H
#include <linux/audit.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <asm/asm-offsets.h> /* For NR_syscalls */
#include <asm/thread_info.h> /* for TS_COMPAT */
#include <asm/unistd.h>
extern const unsigned long sys_call_table[];
/*
* Only the low 32 bits of orig_ax are meaningful, so we return int.
* This importantly ignores the high bits on 64-bit, so comparisons
* sign-extend the low 32 bits.
*/
static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
{
return regs->orig_ax & __SYSCALL_MASK;
}
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
regs->ax = regs->orig_ax & __SYSCALL_MASK;
}
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
unsigned long error = regs->ax;
#ifdef CONFIG_IA32_EMULATION
/*
* TS_COMPAT is set for 32-bit syscall entries and then
* remains set until we return to user mode.
*/
if (task_thread_info(task)->status & TS_COMPAT)
/*
* Sign-extend the value so (int)-EFOO becomes (long)-EFOO
* and will match correctly in comparisons.
*/
error = (long) (int) error;
#endif
return IS_ERR_VALUE(error) ? error : 0;
}
static inline long syscall_get_return_value(struct task_struct *task,
struct pt_regs *regs)
{
return regs->ax;
}
static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
regs->ax = (long) error ?: val;
}
#ifdef CONFIG_X86_32
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
unsigned long *args)
{
BUG_ON(i + n > 6);
memcpy(args, ®s->bx + i, n * sizeof(args[0]));
}
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);
memcpy(®s->bx + i, args, n * sizeof(args[0]));
}
static inline int syscall_get_arch(struct task_struct *task,
struct pt_regs *regs)
{
return AUDIT_ARCH_I386;
}
#else /* CONFIG_X86_64 */
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
unsigned long *args)
{
# ifdef CONFIG_IA32_EMULATION
if (task_thread_info(task)->status & TS_COMPAT)
switch (i) {
case 0:
if (!n--) break;
*args++ = regs->bx;
case 1:
if (!n--) break;
*args++ = regs->cx;
case 2:
if (!n--) break;
*args++ = regs->dx;
case 3:
if (!n--) break;
*args++ = regs->si;
case 4:
if (!n--) break;
*args++ = regs->di;
case 5:
if (!n--) break;
*args++ = regs->bp;
case 6:
if (!n--) break;
default:
BUG();
break;
}
else
# endif
switch (i) {
case 0:
if (!n--) break;
*args++ = regs->di;
case 1:
if (!n--) break;
*args++ = regs->si;
case 2:
if (!n--) break;
*args++ = regs->dx;
case 3:
if (!n--) break;
*args++ = regs->r10;
case 4:
if (!n--) break;
*args++ = regs->r8;
case 5:
if (!n--) break;
*args++ = regs->r9;
case 6:
if (!n--) break;
default:
BUG();
break;
}
}
static inline void syscall_set_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
const unsigned long *args)
{
# ifdef CONFIG_IA32_EMULATION
if (task_thread_info(task)->status & TS_COMPAT)
switch (i) {
case 0:
if (!n--) break;
regs->bx = *args++;
case 1:
if (!n--) break;
regs->cx = *args++;
case 2:
if (!n--) break;
regs->dx = *args++;
case 3:
if (!n--) break;
regs->si = *args++;
case 4:
if (!n--) break;
regs->di = *args++;
case 5:
if (!n--) break;
regs->bp = *args++;
case 6:
if (!n--) break;
default:
BUG();
break;
}
else
# endif
switch (i) {
case 0:
if (!n--) break;
regs->di = *args++;
case 1:
if (!n--) break;
regs->si = *args++;
case 2:
if (!n--) break;
regs->dx = *args++;
case 3:
if (!n--) break;
regs->r10 = *args++;
case 4:
if (!n--) break;
regs->r8 = *args++;
case 5:
if (!n--) break;
regs->r9 = *args++;
case 6:
if (!n--) break;
default:
BUG();
break;
}
}
static inline int syscall_get_arch(struct task_struct *task,
struct pt_regs *regs)
{
#ifdef CONFIG_IA32_EMULATION
/*
* TS_COMPAT is set for 32-bit syscall entry and then
* remains set until we return to user mode.
*
* TIF_IA32 tasks should always have TS_COMPAT set at
* system call time.
*
* x32 tasks should be considered AUDIT_ARCH_X86_64.
*/
if (task_thread_info(task)->status & TS_COMPAT)
return AUDIT_ARCH_I386;
#endif
/* Both x32 and x86_64 are considered "64-bit". */
return AUDIT_ARCH_X86_64;
}
#endif /* CONFIG_X86_32 */
#endif /* _ASM_X86_SYSCALL_H */
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