Re: [PATCH] ARM: drop unused DEBUG_RODATA from XIP_KERNEL

From: Kees Cook
Date: Tue Feb 16 2016 - 16:55:46 EST


On Tue, Feb 16, 2016 at 12:41 PM, Nicolas Pitre
<nicolas.pitre@xxxxxxxxxx> wrote:
> On Tue, 16 Feb 2016, Kees Cook wrote:
>
>> With CONFIG_DEBUG_RODATA not being sensible under XIP_KERNEL, remove it
>> from the XIP linker script.
>
> If so you should also make DEBUG_RODATA depend on !XIP_KERNEL in Kconfig
> to avoid offering a config option that does nothing.

Yeah, that's what Arnd's other patch does. This is intended to follow
his cleanups that do this.

-Kees

>
>> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
>> ---
>> Effectively the patch after Arnd's "ARM: mm: hide
>> __start_rodata_section_aligned for non-debug builds"
>> ---
>> arch/arm/kernel/vmlinux-xip.lds.S | 10 ----------
>> 1 files changed, 0 insertions(+), 10 deletions(-)
>>
>> diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
>> index 40bc4cadb959..cba1ec899a69 100644
>> --- a/arch/arm/kernel/vmlinux-xip.lds.S
>> +++ b/arch/arm/kernel/vmlinux-xip.lds.S
>> @@ -8,9 +8,6 @@
>> #include <asm/thread_info.h>
>> #include <asm/memory.h>
>> #include <asm/page.h>
>> -#ifdef CONFIG_DEBUG_RODATA
>> -#include <asm/pgtable.h>
>> -#endif
>>
>> #define PROC_INFO \
>> . = ALIGN(4); \
>> @@ -92,10 +89,6 @@ SECTIONS
>> HEAD_TEXT
>> }
>>
>> -#ifdef CONFIG_DEBUG_RODATA
>> - . = ALIGN(1<<SECTION_SHIFT);
>> -#endif
>> -
>> .text : { /* Real text segment */
>> _stext = .; /* Text and read-only data */
>> IDMAP_TEXT
>> @@ -115,9 +108,6 @@ SECTIONS
>> ARM_CPU_KEEP(PROC_INFO)
>> }
>>
>> -#ifdef CONFIG_DEBUG_RODATA
>> - . = ALIGN(1<<SECTION_SHIFT);
>> -#endif
>> RO_DATA(PAGE_SIZE)
>>
>> . = ALIGN(4);
>> --
>> 2.6.3
>>
>>
>> --
>> Kees Cook
>> Chrome OS & Brillo Security
>>
>>



--
Kees Cook
Chrome OS & Brillo Security