Re: [Patch v2 1/2] mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL

[David Hildenbrand <david@redhat.com>]

On 19.09.25 09:12, Wei Yang wrote:
> When using mm_slot in ksm, there is code snip like:
> 
>       slot = mm_slot_lookup(mm_slots_hash, mm);
>       mm_slot = mm_slot_entry(slot, struct ksm_mm_slot, slot);
>       if (mm_slot && ..) {
>       }
> 
> The mm_slot_entry() won't return a valid value if slot is NULL
> generally. But currently it works since slot is the first element of
> struct ksm_mm_slot.
> 
> To reduce the ambiguity and make it robust, access mm_slot_entry() when
> slot is !NULL.
> 
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> Cc: Lance Yang <lance.yang@linux.dev>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Dev Jain <dev.jain@arm.com>
> Cc: Kiryl Shutsemau <kirill@shutemov.name>
> Cc: xu.xin16@zte.com.cn
> 
> ---
> v2:
>    * check on slot before continue
> ---

As discussed, we might want to do some other cleanups in that areas 
(e.g., slot never being NULL?). But this here looks cleaner to me for 
the time being.

Acked-by: David Hildenbrand <david@redhat.com>

-- 
Cheers

David / dhildenb