From b4274bbaff787d0f662c427be0ce8df551e593a9 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@armlinux.org.uk>
Date: Wed, 16 Nov 2016 23:51:19 +0000
Subject: [PATCH] ARM: Fix XIP kernels

Commit 1480d4713f7e ("ARM: 8595/2: apply more __ro_after_init") caused
a regression with XIP kernels by moving the __ro_after_init data into
the read-only section.  With XIP kernels, the read-only section is
located in read-only memory from the very beginning.

Work around this by moving the __ro_after_init data back into the .data
section, which will be in RAM, and hence will be writable.

It should be noted that in doing so, this remains writable after init.

Fixes: 1480d4713f7e ("ARM: 8595/2: apply more __ro_after_init")
Reported-by: Andrea Merello <andrea.merello@gmail.com>
Tested-by: Andrea Merello <andrea.merello@gmail.com> [ XIP stm32 ]
Tested-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 arch/arm/kernel/vmlinux-xip.lds.S | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
index 7fa487ef7e2f6..37b2a11af3459 100644
--- a/arch/arm/kernel/vmlinux-xip.lds.S
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -3,6 +3,9 @@
  * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
  */
 
+/* No __ro_after_init data in the .rodata section - which will always be ro */
+#define RO_AFTER_INIT_DATA
+
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/cache.h>
 #include <asm/thread_info.h>
@@ -223,6 +226,8 @@ SECTIONS
 		. = ALIGN(PAGE_SIZE);
 		__init_end = .;
 
+		*(.data..ro_after_init)
+
 		NOSAVE_DATA
 		CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)
 		READ_MOSTLY_DATA(L1_CACHE_BYTES)
-- 
2.39.5