Re: [PATCH v19,RESEND 24/27] x86/vdso: Add __vdso_sgx_enter_enclave() to wrap SGX enclave transitions

From: Sean Christopherson
Date: Fri Mar 22 2019 - 17:20:22 EST


On Wed, Mar 20, 2019 at 05:17:53PM -0700, Xing, Cedric wrote:
> > On Wed, Mar 20, 2019 at 12:57:52PM -0700, Xing, Cedric wrote:
> > > > Using the untrusted stack as a way to exchange data is very
> > > > convenient, but that doesn't mean it's a good idea. Here are some
> > > > problems it
> > > > causes:
> > > >
> > > > - It prevents using a normal function to wrap enclave entry (as
> > > > we're seeing with this patch set).
> > >
> > > It doesn't prevent.
> >
> > Yes it does, keyword being "normal". Though I guess we could do a bit
> > of bikeshedding on the definition of normal...
>
> I don't understand what you mean by "normal".

My apologies, I missed the code snippet in your original code, I was
thinking of a previous idea involving a JMP %rbp. Please ignore this
bit of discussion.