On Thu, Oct 28, 2021 at 01:37:38PM -0700, Reinette Chatre wrote: > The Enclave Page Cache Map (EPCM) is a secure structure used by the > processor to track the contents of the enclave page cache. The EPCM > contains permissions with which enclave pages can be accessed. SGX > support allows EPCM and PTE page permissions to differ - as long as > the PTE permissions do not exceed the EPCM permissions. > > Add a test that: > (1) Creates an SGX enclave page with writable EPCM permission. > (2) Changes the PTE permission on the page to read-only. This should > be permitted because the permission does not exceed the EPCM > permission. > (3) Attempts a write to the page. This should generate a page fault > (#PF) because of the read-only PTE even though the EPCM > permissions allow the page to be written to. > > This introduces the first test of SGX exception handling. In this test > the issue that caused the exception (PTE page permissions) can be fixed > from outside the enclave and after doing so it is possible to re-enter > enclave at original entrypoint with ERESUME. > > Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> /Jarkko
