Re: [tip: x86/urgent] x86/sgx: Set active memcg prior to shmem allocation

From: Kristen Carlson Accardi
Date: Mon Jul 18 2022 - 14:08:54 EST


On Mon, 2022-07-18 at 11:50 +0200, Borislav Petkov wrote:
> Just what I think looks like a discrepancy I noticed while merging
> tip/master:
>
> On Thu, Jun 02, 2022 at 06:27:08PM -0000, tip-bot2 for Kristen
> Carlson Accardi wrote:
> > diff --git a/arch/x86/kernel/cpu/sgx/encl.h
> > b/arch/x86/kernel/cpu/sgx/encl.h
> > index d44e737..332ef35 100644
> > --- a/arch/x86/kernel/cpu/sgx/encl.h
> > +++ b/arch/x86/kernel/cpu/sgx/encl.h
> > @@ -103,10 +103,13 @@ static inline int sgx_encl_find(struct
> > mm_struct *mm, unsigned long addr,
> >  int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
> >                      unsigned long end, unsigned long vm_flags);
> >  
> > +bool current_is_ksgxd(void);
> >  void sgx_encl_release(struct kref *ref);
> >  int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm);
> > -int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long
> > page_index,
> > -                        struct sgx_backing *backing);
> > +int sgx_encl_lookup_backing(struct sgx_encl *encl, unsigned long
> > page_index,
> > +                           struct sgx_backing *backing);
> > +int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long
> > page_index,
> > +                          struct sgx_backing *backing);
> >  void sgx_encl_put_backing(struct sgx_backing *backing);
>
> So this is making the sgx_encl_get_backing() thing static but its
> counterpart sgx_encl_put_backing() is not and is still called by
> other
> places.
>
> Perhaps something wrong with the layering or is this on purpose?
>
> Thx.
>

Hi Boris,

This is intentional - sgx_encl_put_backing() was not changed and will
continue to be used as it previously was.

Thanks,
Kristen