On Mon, Dec 13, 2021 at 02:12:44PM -0800, Reinette Chatre wrote: > Hi Jarkko, > > On 12/10/2021 11:57 PM, Jarkko Sakkinen wrote: > > On Mon, 2021-12-06 at 13:42 -0800, Reinette Chatre wrote: > > > Hi Jarkko, > > > > > > On 12/4/2021 3:08 PM, Jarkko Sakkinen wrote: > > > > On Wed, Dec 01, 2021 at 11:23:08AM -0800, Reinette Chatre wrote: > > > > > In the initial (SGX1) version of SGX, pages in an enclave need to be > > > > > created with permissions that support all usages of the pages, from the > > > > > time the enclave is initialized until it is unloaded. For example, > > > > > pages used by a JIT compiler or when code needs to otherwise be > > > > > relocated need to always have RWX permissions. > > > > > > > > > > SGX2 includes two functions that can be used to modify the enclave page > > > > > permissions of regular enclave pages within an initialized enclave. > > > > > ENCLS[EMODPR] is run from the OS and used to restrict enclave page > > > > > permissions while ENCLU[EMODPE] is run from within the enclave to > > > > > extend enclave page permissions. > > > > > > > > > > Enclave page permission changes need to be approached with care and > > > > > for this reason this initial support is to allow enclave page > > > > > permission changes _only_ if the new permissions are the same or > > > > > more restrictive that the permissions originally vetted at the time the > > > > > pages were added to the enclave. Support for extending enclave page > > > > > permissions beyond what was originally vetted is deferred. > > > > > > > > This paragraph is out-of-scope for a commit message. You could have > > > > this in the cover letter but not here. I would just remove it. > > > > > > I think this is essential information that is mentioned in the cover > > > letter _and_ in this changelog. I will follow Dave's guidance and avoid > > > "deferred" by just removing that last sentence. > > > > > > > > > > > > Whether enclave page permissions are restricted or extended it > > > > > is necessary to ensure that the page table entries and enclave page > > > > > permissions are in sync. Introduce a new ioctl, SGX_IOC_PAGE_MODP, to > > > > > > > > SGX_IOC_PAGE_MODP does not match the naming convetion of these: > > > > > > > > * SGX_IOC_ENCLAVE_CREATE > > > > * SGX_IOC_ENCLAVE_ADD_PAGES > > > > * SGX_IOC_ENCLAVE_INIT > > > > > > ah - my understanding was that the SGX_IOC_ENCLAVE prefix related to > > > operations related to the entire enclave and thus I introduced the > > > prefix SGX_IOC_PAGE to relate to operations on pages within an enclave. > > > > SGX_IOC_ENCLAVE_ADD_PAGES is also operation working on pages within an > > enclave. > > > > Also, to be aligned with SGX_IOC_ENCLAVE_ADD_PAGES, the new operations > > should also take secinfo as input. > > ok, will do. > > > > > > > > > > > > > > A better name would be SGX_IOC_ENCLAVE_MOD_PROTECTIONS. It doesn't > > > > do harm to be a more verbose. > > > > > > Will do. I see later you propose SGX_IOC_ENCLAVE_MODIFY_TYPE - would you > > > like them to be consistent wrt MOD/MODIFY? > > > > I would considering introducing just one new ioctl: > > > > SGX_IOC_ENCLAVE_MODIFY_PAGES > > > > and choose either operations based on e.g. a flag > > (see flags field SGX_IOC_ENCLAVE_ADD_PAGES). > > > > There seems to be different opinion about the single ioctl() as per:https://lore.kernel.org/lkml/0fb14185-5cc3-a963-253d-2e119b4a52bb@xxxxxxxxx/ > > I thus plan to proceed with the two ioctls, both taking secinfo as input. > Would that be ok with you? Yeah, let's continue with two ioctls for now, I agree. /Jarkko
