[patch V3 20/32] x86/exceptions: Enable IST guard pages

[Thomas Gleixner <tglx@linutronix.de>]

All usage sites which expected that the exception stacks in the CPU entry
area are mapped linearly are fixed up. Enable guard pages between the
IST stacks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/cpu_entry_area.h |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

--- a/arch/x86/include/asm/cpu_entry_area.h
+++ b/arch/x86/include/asm/cpu_entry_area.h
@@ -26,13 +26,9 @@ struct exception_stacks {
 	ESTACKS_MEMBERS(0)
 };
 
-/*
- * The effective cpu entry area mapping with guard pages. Guard size is
- * zero until the code which makes assumptions about linear mappings is
- * cleaned up.
- */
+/* The effective cpu entry area mapping with guard pages. */
 struct cea_exception_stacks {
-	ESTACKS_MEMBERS(0)
+	ESTACKS_MEMBERS(PAGE_SIZE)
 };
 
 /*