On 3/17/19 2:14 PM, Jarkko Sakkinen wrote: > + /* > + * Access is blocked by the Enclave Page Cache Map (EPCM), i.e. the > + * access is allowed by the PTE but not the EPCM. This usually happens > + * when the EPCM is yanked out from under us, e.g. by hardware after a > + * suspend/resume cycle. In any case, software, i.e. the kernel, can't > + * fix the source of the fault as the EPCM can't be directly modified > + * by software. Handle the fault as an access error in order to signal > + * userspace, e.g. so that userspace can rebuild their enclave(s), even > + * though userspace may not have actually violated access permissions. > + */ > + if (unlikely(error_code & X86_PF_SGX)) > + return 1; A sanitized error_code gets passed up to userspace. Is that how userspace figures out that this was a PF_SGX fault instead of something more routine?
