Re: [PATCH 1/2] x86/sgx: Resolve EAUG race where losing thread returns SIGBUS

[Jarkko Sakkinen]

On Mon Apr 29, 2024 at 4:04 PM EEST, Jarkko Sakkinen wrote:
> > Fix these two bugs (1) by returning VM_FAULT_NOPAGE to the generic Linux
> > fault handler so that no signal is sent to userspace, and (2) by
> > replacing sgx_encl_free_epc_page() with sgx_free_epc_page() so that no
> > EREMOVE is performed.
>
> What is the collateral damage caused by ENCLS[EREMOVE]?

Have you measured cost of eremove on an empty page?

I tried to lookup for a thread from lore because I have a faint memory
that it was concluded that its cost irrelevant. Please correct if I'm
wrong.

BR, Jarkko