[PATCH 1/2] ARM: mm: DEBUG_RODATA makes no sense with XIP_KERNEL
From: Kees Cook <hidden>
Date: 2016-02-16 20:31:21
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On Tue, Feb 16, 2016 at 8:03 AM, Arnd Bergmann [off-list ref] wrote:
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@arndb.de>
Fixes: 25362dc496ed ("ARM: 8501/1: mm: flip priority of CONFIG_DEBUG_RODATA")For this and the 2/2 patch: Acked-by: Kees Cook <redacted> I've sent follow-up to clean up the XIP linker script too, if you want to take that as the 3rd patch in this series of fixes. -Kees
quoted hunk ↗ jump to hunk
--- 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
-- Kees Cook Chrome OS & Brillo Security