Re: [PATCH 1/3] slab: check the return value of check_bytes_and_report()

[Chengming Zhou <chengming.zhou@linux.dev>]

On 2024/5/30 23:20, Christoph Lameter (Ampere) wrote:
> On Tue, 28 May 2024, Chengming Zhou wrote:
> 
>> diff --git a/mm/slub.c b/mm/slub.c
>> index 0809760cf789..de57512734ac 100644
>> --- a/mm/slub.c
>> +++ b/mm/slub.c
>> @@ -1324,9 +1324,10 @@ static int check_object(struct kmem_cache *s, struct slab *slab,
>>         }
>>     } else {
>>         if ((s->flags & SLAB_POISON) && s->object_size < s->inuse) {
>> -            check_bytes_and_report(s, slab, p, "Alignment padding",
>> +            if (!check_bytes_and_report(s, slab, p, "Alignment padding",
>>                 endobject, POISON_INUSE,
>> -                s->inuse - s->object_size);
>> +                s->inuse - s->object_size))
>> +                return 0;
>>         }
>>     }
> 
> This change means we will then skip the rest of the checks in check_object() such as the poison check.

Yeah, only when this padding checking failed.

Now, we always abort checking and return 0 when the first checking error happens,
such as redzones checking above.

Thanks.