Re: [PATCH v15 2/4] kasan: allow architectures to provide an outline readiness check

[Daniel Axtens <dja@axtens.net>]

>> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
>> index 10177cc26d06..0ad615f3801d 100644
>> --- a/mm/kasan/common.c
>> +++ b/mm/kasan/common.c
>> @@ -331,6 +331,10 @@ static inline bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
>>         u8 tag;
>>         void *tagged_object;
>>
>> +       /* Bail if the arch isn't ready */
>
> This comment brings no value. The fact that we bail is clear from the
> following line. The comment should explain why we bail.
>
>> +       if (!kasan_arch_is_ready())
>> +               return false;

Fair enough, I've just dropped the comments as I don't think there's
really a lot of scope for the generic/core comment to explain why a
particular architecture might not be ready.

> Have you considered including these checks into the high-level
> wrappers in include/linux/kasan.h? Would that work?

I don't think those wrappers will catch the outline check functions
like __asan_load*, which also need guarding.

Kind regards,
Daniel