Re: [PATCH v11 09/13] x86, sgx: basic routines for enclave page cache

[Jarkko Sakkinen]

On Wed, 2018-06-20 at 08:26 -0700, Sean Christopherson wrote:
> >  bool sgx_enabled __ro_after_init = false;
> >  EXPORT_SYMBOL(sgx_enabled);
> > +bool sgx_lc_enabled __ro_after_init;
> > +EXPORT_SYMBOL(sgx_lc_enabled);
> > +atomic_t sgx_nr_free_pages = ATOMIC_INIT(0);
> > +EXPORT_SYMBOL(sgx_nr_free_pages);
> > +struct sgx_epc_bank sgx_epc_banks[SGX_MAX_EPC_BANKS];
> > +EXPORT_SYMBOL(sgx_epc_banks);
> > +int sgx_nr_epc_banks;
> > +EXPORT_SYMBOL(sgx_nr_epc_banks);
> > +LIST_HEAD(sgx_active_page_list);
> > +EXPORT_SYMBOL(sgx_active_page_list);
> > +DEFINE_SPINLOCK(sgx_active_page_list_lock);
> > +EXPORT_SYMBOL(sgx_active_page_list_lock);
> 
> I don't think we should be exporting anything other than sgx_enabled
> and sgx_lc_enabled.  The only external use of a symbol that can't be
> trivially (re)moved is in the driver's sgx_pm_suspend() in sgx_main.c,
> which uses the sgx_active_page_list to invalidate enclaves.  And that
> behavior seems unsafe, e.g. an enclave could theoretically have zero
> pages on the active list and so could be missed in the suspend flow.

Fully agreed. Just forgotten cruft...

/Jarkko