From c7ea591c91162a203a5961d69f5c86a6ef9d50c1 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@ftp.linux.org.uk>
Date: Thu, 18 Aug 2011 20:10:19 +0100
Subject: um: increase stack growth cushion in pagefault

analog of [PATCH] i386: let usermode execute the "enter" instruction from
circa 2006.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
---
 arch/x86/um/asm/processor.h | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'arch/x86/um/asm/processor.h')

diff --git a/arch/x86/um/asm/processor.h b/arch/x86/um/asm/processor.h
index d3ac1cecf0f4..f34c4b2d09f3 100644
--- a/arch/x86/um/asm/processor.h
+++ b/arch/x86/um/asm/processor.h
@@ -10,6 +10,9 @@
 # include "processor_64.h"
 #endif
 
+#define ARCH_IS_STACKGROW(address) \
+       (address + 65536 + 32 * sizeof(unsigned long) >= UPT_SP(&current->thread.regs.regs))
+
 #include <asm/processor-generic.h>
 
 #endif
-- 
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