Re: [PATCH v28 21/22] x86/vdso: Implement a vDSO for Intel SGX enclave call

[Jarkko Sakkinen]

On Mon, 2020-03-16 at 09:57 -0400, Nathaniel McCallum wrote:
> For the vDSO, only marginally. I'm counting +4,-2 instructions in my
> suggestions. For the wrapper, things become significantly simpler.

Simpler is not a quality that has very high importance here except
when it comes to vDSO.

At least it is not enough to change to vDSO. What else?

Anyway, I think the documentation should fixed and streamlined 1st.

It is way too verbose prose in some places and in some it completely
lacks the information e.g.

"Debug Exceptions (#DB) and Breakpoints (#BP) are ever fixed up and are
always delivered via standard signals."

Never should state things like that without explaining the reasons.

On the other hand:

"Most exceptions reported on ENCLU, including those that occur within
the enclave, are fixed up and reported synchronously instead of being
delivered via a standard signal. Debug Exceptions (#DB) and Breakpoints
(#BP) are never fixed up and are always delivered via standard signals.
On synchrously reported exceptions, -EFAULT is returned and details
about the exception are recorded in @e, the optional
sgx_enclave_exception struct."

Duplicates information already elsewhere (e.g. return values) and is
just pain to read and comprehend in general.

/Jarkko