linux-kernel - [PATCH 1/2] ARM: mm: DEBUG_RODATA makes no sense with XIP

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Message-Id: <1455638631-3326518-1-git-send-email-arnd@arndb.de>
Date:	Tue, 16 Feb 2016 17:03:26 +0100
From:	Arnd Bergmann <arnd@...db.de>
To:	Russell King <linux@....linux.org.uk>
Cc:	linux-arm-kernel@...ts.infradead.org,
	Arnd Bergmann <arnd@...db.de>,
	Kees Cook <keescook@...omium.org>,
	Laura Abbott <labbott@...oraproject.org>,
	Ard Biesheuvel <ard.biesheuvel@...aro.org>,
	linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] ARM: mm: DEBUG_RODATA makes no sense with XIP_KERNEL

When CONFIG_DEBUG_ALIGN_RODATA is set, we get a link error:

arch/arm/mm/built-in.o:(.data+0x4bc): undefined reference to `__start_rodata_section_aligned'

However, this combination is useless, as XIP_KERNEL implies that all the
RODATA is already marked readonly, so both CONFIG_DEBUG_RODATA and
CONFIG_DEBUG_ALIGN_RODATA (which depends on the other) are not
needed with XIP_KERNEL, and this patches enforces that using a Kconfig
dependency.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
Fixes: 25362dc496ed ("ARM: 8501/1: mm: flip priority of CONFIG_DEBUG_RODATA")
---
 arch/arm/mm/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index fbf2296388ce..8894045caba9 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -1039,7 +1039,7 @@ config ARCH_SUPPORTS_BIG_ENDIAN
 
 config DEBUG_RODATA
 	bool "Make kernel text and rodata read-only"
-	depends on MMU
+	depends on MMU && !XIP_KERNEL
 	default y if CPU_V7
 	help
 	  If this is set, kernel text and rodata memory will be made
-- 
2.7.0