Re: RFC: userspace exception fixups

[Linus Torvalds]

On Thu, Nov 1, 2018 at 12:31 PM Rich Felker <dalias@xxxxxxxx> wrote:
>
> See my other emails in this thread. You would register the *address*
> (in TLS) of a function pointer object pointing to the handler, rather
> than the function address of the handler. Then switching handler is
> just a single store in userspace, no syscalls involved.

Yes.

And for just EENTER, maybe that's the right model.

If we want to generalize it to other thread-synchronous faults, it
needs way more information and a list of handlers, but if we limit the
thing to _only_ EENTER getting an SGX fault, then a single "this is
the fault handler" address is probably the right thing to do.

                     Linus