[PATCH] x86/x86_64: mark rodata section read only: x86 parts

x86 specific parts to make the .rodata section read only

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/Kconfig.debug b/arch/i386/Kconfig.debug
index c48b424..bf32ecc 100644
--- a/arch/i386/Kconfig.debug
+++ b/arch/i386/Kconfig.debug
@@ -42,6 +42,16 @@
 	  This results in a large slowdown, but helps to find certain types
 	  of memory corruptions.
 
+config DEBUG_RODATA
+	bool "Write protect kernel read-only data structures"
+	depends on DEBUG_KERNEL
+	help
+	  Mark the kernel read-only data as write-protected in the pagetables,
+	  in order to catch accidental (and incorrect) writes to such const
+	  data. This option may have a slight performance impact because a
+	  portion of the kernel code won't be covered by a 2MB TLB anymore.
+	  If in doubt, say "N".
+
 config 4KSTACKS
 	bool "Use 4Kb for kernel stacks instead of 8Kb"
 	depends on DEBUG_KERNEL