On 2018-11-21 04:25, Jarkko Sakkinen wrote:
On Tue, Nov 20, 2018 at 07:19:37AM -0800, Andy Lutomirski wrote:general by mucking with some regs and retrying -- that will infinite loop and confuse everyone. I'm not even 100% convinced that decoding the insn stream is useful -- AEP can point to something that isn't ENCLU.In my return-to-AEP approach to whole point was not to do any decoding but instead have something else always in the AEP handler than just ENCLU. No instruction decoding. No RIP manipulation.IOW the kernel needs to know *when* to apply this special behavior. Sadly there is no bit in the exception frame that says "came from SGX".
Jarkko, can you please explain you solution in detail? The CPU receives an exception. This will be handled by the kernel exception handler. What information does the kernel exception handler use to determine whether to deliver the exception as a regular signal to the process, or whether to set the special registers values for userspace and just continue executing the process manually?
-- Jethro Beekman | Fortanix
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