Re: [PATCH] arch/avr32/mm/cache.c: export symbol flush_icache_range() for module using

[Chen Gang <gang.chen.5i5j@gmail.com>]

On 03/09/2014 11:19 PM, Chen Gang wrote:
> On 03/09/2014 06:17 AM, Hans-Christian Egtvedt wrote:
>> Around Sun 09 Mar 2014 05:47:04 +0800 or thereabout, Chen Gang wrote:
>>>
>>> After this patch, our linux kernel can pass "avr32-linux-" allmodconfig
>>> (it contents quite a few of warnings, but after check, I guess they are
>>> not kernel's issue).
>>
>> That sounds great, I am a bit surprised however that the lkdtm module need
>> flush_icache_range. Would have been interesting to look into what causes this
>> dependency.
>>

After read a little more details for lkdtm, I guess "after overwrite an
executable area by do_nothing(), it needs flush_icache_range() to be
sure the new instructions/data must have effect with all cpu".

Welcome any additional information for it.

Thanks.

> 
> "driver/misc/lkdtm.c" will use this flush_icache_range().
> 
> And some architectures export it to modules.
> 
>   [root@gchen arch]# grep -rn flush_icache_range * | grep EXPORT
>   arm64/mm/flush.c:105:EXPORT_SYMBOL(flush_icache_range);
>   avr32/mm/cache.c:114:EXPORT_SYMBOL(flush_icache_range);
>   m68k/mm/cache.c:106:EXPORT_SYMBOL(flush_icache_range);
>   mn10300/mm/cache-inv-icache.c:129:EXPORT_SYMBOL(flush_icache_range);
>   mn10300/mm/cache-flush-icache.c:155:EXPORT_SYMBOL(flush_icache_range);
>   sparc/mm/init_64.c:435:EXPORT_SYMBOL(flush_icache_range);
> 
> 
> Welcome any more details information by any other members, thanks.
> 
> 

Thanks.
-- 
Chen Gang

Open, share and attitude like air, water and life which God blessed