Re: [PATCH] x86/sgx: fix a NULL pointer

[Dave Hansen]

On 7/17/23 13:29, Haitao Huang wrote:
> Under heavy load, the SGX EPC reclaimers (current ksgxd or future EPC
> cgroup worker) may reclaim the SECS EPC page for an enclave and set
> encl->secs.epc_page to NULL. But the SECS EPC page is used for EAUG in
> the SGX #PF handler without checking for NULL and reloading.
> 
> Fix this by checking if SECS is loaded before EAUG and load it if it was
> reclaimed.

It would be nice to see a _bit_ more theory of the bug in here.

What is an SECS page and why is it special in a reclaim context?  Why is
this so hard to hit?  What led you to discover this issue now?  What is
EAUG?