Re: [kernel-hardening] Re: [PATCH] ARM: mm: add testcases for RODATA

Laura Abbott
2017-01-18T23:38:52Z

On 01/18/2017 02:36 PM, Russell King - ARM Linux wrote:
> On Wed, Jan 18, 2017 at 11:20:54AM -0800, Laura Abbott wrote:
>> On 01/18/2017 05:53 AM, Jinbum Park wrote:
>>> diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
>>> index bdd283b..741e2e8 100644
>>> --- a/arch/arm/include/asm/cacheflush.h
>>> +++ b/arch/arm/include/asm/cacheflush.h
>>> @@ -498,6 +498,16 @@ static inline void set_kernel_text_rw(void) { }
>>> static inline void set_kernel_text_ro(void) { }
>>> #endif
>>>
>>> +#ifdef CONFIG_DEBUG_RODATA_TEST
>>> +extern const int rodata_test_data;
>>> +int rodata_test(void);
>>> +#else
>>> +static inline int rodata_test(void)
>>> +{
>>> + return 0;
>>> +}
>>> +#endif
>>> +
>
> I don't see why this needs to be in cacheflush.h - it doesn't seem to
> have anything to do with cache flushing, and placing it in here means
> that if you change the state of CONFIG_DEBUG_RODATA_TEST, most likely
> the entire kernel gets rebuilt. Please put it in a separate header
> file.
>

cacheflush.h seems to be where all the set_memory_* functions have
ended up. I was just looking at cleaning that up unless someone
beats me to it.

Thanks,
Laura