Re: [RFC/PATCH bpf-next 2/3] mm/bpf: Add bpf_get_kmem_cache() kfunc

[Namhyung Kim <namhyung@xxxxxxxxxx>]

On Sun, Sep 29, 2024 at 10:05:42AM -0700, Alexei Starovoitov wrote:
> On Fri, Sep 27, 2024 at 11:41 AM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> >
> > +__bpf_kfunc struct kmem_cache *bpf_get_kmem_cache(u64 addr)
> > +{
> > +       struct slab *slab;
> > +
> > +       slab = virt_to_slab((void *)(long)addr);
> > +       return slab ? slab->slab_cache : NULL;
> > +}
> 
> I think this needs more safety guards on 'addr'.
> It needs to check the valid range of 'addr' before doing virt_to_slab.

Ok, I think we can use virt_addr_valid() for that.

Thanks,
Namhyung