commit c7ea591c91162a203a5961d69f5c86a6ef9d50c1
author Al Viro <viro@ftp.linux.org.uk> Thu Aug 18 20:10:19 2011 +0100
committer Richard Weinberger <richard@nod.at> Wed Nov 02 14:15:19 2011 +0100
tree 06fd34b8f1b2009c3266b587b6024c62db6920fe
parent 3579a389730dd74d9f280152c52aa851dd1da860

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

diff --git a/arch/x86/um/asm/processor.h b/arch/x86/um/asm/processor.h
index d3ac1ce..f34c4b2 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