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