From 80d6b0c2eed2a504f6740cd1f5ea76dc50abfc4d Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Thu, 3 Apr 2014 13:29:50 -0700
Subject: ARM: mm: allow text and rodata sections to be read-only

This introduces CONFIG_DEBUG_RODATA, making kernel text and rodata
read-only. Additionally, this splits rodata from text so that rodata can
also be NX, which may lead to wasted memory when aligning to SECTION_SIZE.
The read-only areas are made writable during ftrace updates and kexec.

Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <lauraa@codeaurora.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
---
 arch/arm/kernel/vmlinux.lds.S | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'arch/arm/kernel/vmlinux.lds.S')

diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 18fd68a295ea..3afcb6c2cf06 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -120,6 +120,9 @@ SECTIONS
 			ARM_CPU_KEEP(PROC_INFO)
 	}
 
+#ifdef CONFIG_DEBUG_RODATA
+	. = ALIGN(1<<SECTION_SHIFT);
+#endif
 	RO_DATA(PAGE_SIZE)
 
 	. = ALIGN(4);
-- 
cgit