commit 637716a3825e186555361574aa1fa3c0ebf8018b
author Andi Kleen <ak@suse.de> Mon May 16 21:53:20 2005 -0700
committer Linus Torvalds <torvalds@ppc970.osdl.org> Tue May 17 07:59:13 2005 -0700
tree 84401d191be109af6eaf2bbf9ad5ae4b6be1260a
parent 10ffdbb8d605be88b148f127ec86452f1364d4f0

[PATCH] x86_64: Add a guard page at the end of the 47bit address space

This works around a bug in the AMD K8 CPUs.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-x86_64/processor.h

diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h
index f0581c3..9f74a28 100644
--- a/include/asm-x86_64/processor.h
+++ b/include/asm-x86_64/processor.h
@@ -159,9 +159,9 @@
 
 
 /*
- * User space process size. 47bits.
+ * User space process size. 47bits minus one guard page.
  */
-#define TASK_SIZE	(0x800000000000UL)
+#define TASK_SIZE	(0x800000000000UL - 4096)
 
 /* This decides where the kernel will search for a free chunk of vm
  * space during mmap's.