On Thu, Aug 20, 2020 at 05:31:14PM +0200, Borislav Petkov wrote: > On Thu, Jul 16, 2020 at 04:52:42PM +0300, Jarkko Sakkinen wrote: > > From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > > > > Include SGX bit to the PF error codes and throw SIGSEGV with PF_SGX when > > a #PF with SGX set happens. > > > > CPU throws a #PF with the SGX set in the event of Enclave Page Cache Map > > (EPCM) conflict. The EPCM is a CPU-internal table, which describes the > > properties for a enclave page. Enclaves are measured and signed software > > entities, which SGX hosts. [1] > > > > Although the primary purpose of the EPCM conflict checks is to prevent > > malicious accesses to an enclave, an illegit access can happen also for > > legit reasons. > > > > All SGX reserved memory, including EPCM is encrypted with a transient key > > that does not survive from the power transition. Throwing a SIGSEGV allows > > user space software to react when this happens (e.g. recreate the enclave, > > which was invalidated). > > > > [1] Intel SDM: 36.5.1 Enclave Page Cache Map (EPCM) > > > > Acked-by: Jethro Beekman <jethro@xxxxxxxxxxxx> > > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> > > --- > > arch/x86/include/asm/traps.h | 14 ++++++++------ > > arch/x86/mm/fault.c | 13 +++++++++++++ > > 2 files changed, 21 insertions(+), 6 deletions(-) > > Reviewed-by: Borislav Petkov <bp@xxxxxxx> Thank you. Appended to the commit. > > -- > Regards/Gruss, > Boris. > > https://people.kernel.org/tglx/notes-about-netiquette /Jarkko
