| Date | Thu, 20 Aug 2020 17:31:14 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v36 03/24] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX |
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On Thu, Jul 16, 2020 at 04:52:42PM +0300, Jarkko Sakkinen wrote: > From: Sean Christopherson <sean.j.christopherson@intel.com> > > 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@fortanix.com> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > --- > 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@suse.de>
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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