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Date:   Fri, 22 Mar 2019 14:20:15 -0700
From:   Sean Christopherson <sean.j.christopherson@intel.com>
To:     "Xing, Cedric" <cedric.xing@intel.com>
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Subject: Re: [PATCH v19,RESEND 24/27] x86/vdso: Add
 __vdso_sgx_enter_enclave() to wrap SGX enclave transitions
Message-ID: <20190322212011.GD12666@linux.intel.com>
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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.