x86: syscall_get_nr returns int

Make syscall_get_nr() return int, so we always sign-extend
the low 32 bits of orig_ax in checks.

Signed-off-by: Roland McGrath <roland@redhat.com>
This commit is contained in:
Roland McGrath 2009-09-22 19:57:51 -07:00
parent 268e46712d
commit 18c1e2c80d

View File

@ -1,7 +1,7 @@
/*
* Access to user system call parameters and results
*
* Copyright (C) 2008 Red Hat, Inc. All rights reserved.
* 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
@ -16,13 +16,13 @@
#include <linux/sched.h>
#include <linux/err.h>
static inline long syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
/*
* We always sign-extend a -1 value being set here,
* so this is always either -1L or a syscall number.
* 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;
}