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Subject[PATCH 2/4] x86: syscall_get_nr returns int
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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>
---
arch/x86/include/asm/syscall.h | 14 +++++++-------
1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index d82f39b..8d33bc5 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -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)
+/*
+ * 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)
{
- /*
- * We always sign-extend a -1 value being set here,
- * so this is always either -1L or a syscall number.
- */
return regs->orig_ax;
}


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