Re: [PATCH mm] kfence, slab: fix cache_alloc_debugcheck_after() for bulk allocations

From: Alexander Potapenko
Date: Thu Mar 04 2021 - 16:07:54 EST


On Thu, Mar 4, 2021 at 9:53 PM Marco Elver <elver@xxxxxxxxxx> wrote:
>
> cache_alloc_debugcheck_after() performs checks on an object, including
> adjusting the returned pointer. None of this should apply to KFENCE
> objects. While for non-bulk allocations, the checks are skipped when we
> allocate via KFENCE, for bulk allocations cache_alloc_debugcheck_after()
> is called via cache_alloc_debugcheck_after_bulk().

@Andrew, is this code used by anyone?
As far as I understand, it cannot be enabled by any config option, so
nobody really tests it.
If it is still needed, shall we promote #if DEBUGs in slab.c to a
separate config option, or maybe this code can be safely removed?


Alex