Re: [PATCH 1/2] x86/sgx: Do not fail on incomplete sanitization on premature stop of ksgxd

From: Huang, Kai
Date: Mon Sep 05 2022 - 07:32:52 EST


On Mon, 2022-09-05 at 12:44 +0300, jarkko@xxxxxxxxxx wrote:
> On Mon, Sep 05, 2022 at 07:50:33AM +0000, Huang, Kai wrote:
> > On Sat, 2022-09-03 at 13:26 +0300, Jarkko Sakkinen wrote:
> > > >   static int ksgxd(void *p)
> > > >   {
> > > > + unsigned long left_dirty;
> > > > +
> > > >    set_freezable();
> > > >  
> > > >    /*
> > > >    * Sanitize pages in order to recover from kexec(). The 2nd pass is
> > > >    * required for SECS pages, whose child pages blocked EREMOVE.
> > > >    */
> > > > - __sgx_sanitize_pages(&sgx_dirty_page_list);
> > > > - __sgx_sanitize_pages(&sgx_dirty_page_list);
> > > > + left_dirty = __sgx_sanitize_pages(&sgx_dirty_page_list);
> > > > + pr_debug("%ld unsanitized pages\n", left_dirty);
> > >                   %lu
> > >
> >
> > I assume the intention is to print out the unsanitized SECS pages, but what is
> > the value of printing it? To me it doesn't provide any useful information, even
> > for debug.
>
> How do you measure "useful"?
>
> If for some reason there were unsanitized pages, I would at least
> want to know where it ended on the first value.

Using pr_debug() means it's for debugging the driver, but to me it doesn't help
on debugging the driver, so it is not useful.

Anyway, I will stop argue here.

--
Thanks,
-Kai