On Wed, May 11, 2022 at 10:23:29AM -0700, Reinette Chatre wrote: > Hi Jarkko, > > On 5/10/2022 3:28 PM, Jarkko Sakkinen wrote: > > Let's just say that I came a bit late to the series, and should have read > > the whole thread before responding to anything. As long as enclave lock is > > kept on both sides things should be fine. > > For the most part, yes. The remaining scenario is the case when the reclaimer > releases the enclave mutex while keeping a reference to the backing store pages. > By releasing the enclave mutex there is opportunity for page fault > handler to run and also operate on the backing store. Both the reclaimer > (after patch 3/4 in this series) and page fault handler operate on > the backing store with enclave mutex held but if that is done without > taking backing store references into account data could be lost. This is > addressed in the following series with: > https://lore.kernel.org/linux-sgx/d0ace4a1770ab8f4196bfeae06d0970ddb14ef01.1652131695.git.reinette.chatre@xxxxxxxxx/ Right, I get it now. Great job figuring all this out! > > > > I think for bugs like these it would make sense to put them out early as > > possible, e.g. I would be fine getting them from kernel bugzilla. Now there > > there was two week latency on finding the issue, and making it public. > > Unless there is something confidential, it would be best to get early > > alert. I'm always ready to change my priorities to help to fix such issues. > > I am sorry about this. The reason I first struggled with this by myself was > because it was made out to be an SGX2 issue. This was made worse when I was not > able to create an SGX1 test case that can trigger the issue. I thus lacked > evidence that it is an upstream issue and it took me a while to debug and > understand the issue to gain confidence that it is indeed an upstream issue. No worries, just making the crash log available early on gives a chance to investigate it :-) We can then figure out whether it is SGX2 issue or not, or any other circumstance. There should be a low-barrier to do this. E.g. I happened to get sick when the series was posted, and therefore lagged on investigation. Giving the maximum amount of window here is super important. > Reinette BR, Jarkko
