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From: Suren Baghdasaryan <surenb@google.com>
Date: Mon, 12 Feb 2024 18:20:13 -0800
Message-ID: <CAJuCfpGkdAy58nR02_PSVXc4=R3faRUL-7Hack3R_aWmAgk5HA@mail.gmail.com>
Subject: Re: [PATCH v3 05/35] mm: introduce slabobj_ext to support slab object extensions
To: Kees Cook <keescook@chromium.org>
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On Mon, Feb 12, 2024 at 2:14=E2=80=AFPM Kees Cook <keescook@chromium.org> w=
rote:
>
> On Mon, Feb 12, 2024 at 01:38:51PM -0800, Suren Baghdasaryan wrote:
> > Currently slab pages can store only vectors of obj_cgroup pointers in
> > page->memcg_data. Introduce slabobj_ext structure to allow more data
> > to be stored for each slab object. Wrap obj_cgroup into slabobj_ext
> > to support current functionality while allowing to extend slabobj_ext
> > in the future.
> >
> > Signed-off-by: Suren Baghdasaryan <surenb@google.com>
>
> It looks like this doesn't change which buckets GFP_KERNEL_ACCOUNT comes
> out of, is that correct? I'd love it if we didn't have separate buckets
> so GFP_KERNEL and GFP_KERNEL_ACCOUNT came from the same pools (so that
> the randomized pools would cover GFP_KERNEL_ACCOUNT ...)

This should not affect KMEM accounting in any way. We are simply
changing the vector of obj_cgroup objects to hold complex objects
which can contain more fields in addition to the original obj_cgroup
(in our case it's the codetag reference).
Unless I misunderstood your question?

>
> Regardless:
>
> Reviewed-by: Kees Cook <keescook@chromium.org>
>
> --
> Kees Cook