Re: [PATCH v38 03/24] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX
From: Jarkko Sakkinen
Date: Wed Sep 16 2020 - 16:30:36 EST
On Wed, Sep 16, 2020 at 01:44:48PM +0200, Borislav Petkov wrote:
> On Tue, Sep 15, 2020 at 02:28:21PM +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. 
> > 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).
> >  Intel SDM: 36.5.1 Enclave Page Cache Map (EPCM)
> > Acked-by: Jethro Beekman <jethro@xxxxxxxxxxxx>
> > Reviewed-by: Darren Kenny <darren.kenny@xxxxxxxxxx>
> > Reviewed-by: Borislav Petkov <bp@xxxxxxx>
> > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> > ---
> > arch/x86/include/asm/traps.h | 14 ++++++++------
> The SEV-ES patchset moved that to arch/x86/include/asm/trap_pf.h but
> fixing that up is real easy. Simply do this search-replace
> on this patch.
Hey, I just did
git fetch mainline && git rebase mainline/master
Zero conflicts and there is no trap_pf.h yet. So this is not yet in