On 8/27/19 12:07 PM, Nick Hu wrote:
> Hi Andrey
>
> On Thu, Aug 22, 2019 at 11:59:02PM +0800, Andrey Ryabinin wrote:
>> On 8/7/19 10:19 AM, Nick Hu wrote:
>>> There are some features which need this string operation for compilation,
>>> like KASAN. So the purpose of this porting is for the features like KASAN
>>> which cannot be compiled without it.
>>>
>>
>> Compilation error can be fixed by diff bellow (I didn't test it).
>> If you don't need memmove very early (before kasan_early_init()) than
>> arch-specific not-instrumented memmove()
>> isn't necessary to have.
>>
>> ---
>> mm/kasan/common.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
>> index 6814d6d6a023..897f9520bab3 100644
>> --- a/mm/kasan/common.c
>> +++ b/mm/kasan/common.c
>> @@ -107,6 +107,7 @@ void *memset(void *addr, int c, size_t len)
>> return __memset(addr, c, len);
>> }
>>
>> +#ifdef __HAVE_ARCH_MEMMOVE
>> #undef memmove
>> void *memmove(void *dest, const void *src, size_t len)
>> {
>> @@ -115,6 +116,7 @@ void *memmove(void *dest, const void *src, size_t len)
>>
>> return __memmove(dest, src, len);
>> }
>> +#endif
>>
>> #undef memcpy
>> void *memcpy(void *dest, const void *src, size_t len)
>> --
>> 2.21.0
>>
>>
>>
> I have confirmed that the string operations are not used before
> kasan_early_init().
> But I can't make sure whether other ARCHs would need it before
> kasan_early_init().
> Do you have any idea to check that? Should I cc all other ARCH maintainers?
This doesn't affect other ARCHes in any way. If other arches have their own
not-instrumented
memmove implementation (and they do), they will continue to be able to use it
early.
