Re: [PATCH v22 05/24] x86/sgx: Add ENCLS architectural error codes

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Fri, Sep 27, 2019 at 12:20:13PM +0200, Borislav Petkov wrote:
> On Tue, Sep 03, 2019 at 05:26:36PM +0300, Jarkko Sakkinen wrote:
> > Document ENCLS architectural error codes. These error codes are returned by
> > the SGX opcodes. Make the header as part of the uapi so that they can be
> > used in some situations directly returned to the user space (ENCLS[EINIT]
> > leaf function error codes could be one potential use case).
> > 
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> > ---
> >  arch/x86/include/uapi/asm/sgx_errno.h | 91 +++++++++++++++++++++++++++
> >  1 file changed, 91 insertions(+)
> >  create mode 100644 arch/x86/include/uapi/asm/sgx_errno.h
> > 
> > diff --git a/arch/x86/include/uapi/asm/sgx_errno.h b/arch/x86/include/uapi/asm/sgx_errno.h
> > new file mode 100644
> > index 000000000000..48b87aed58d7
> > --- /dev/null
> > +++ b/arch/x86/include/uapi/asm/sgx_errno.h
> > @@ -0,0 +1,91 @@
> > +/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
> > +/*
> > + * Copyright(c) 2018 Intel Corporation.
> > + *
> > + * Contains the architecturally defined error codes that are returned by SGX
> > + * instructions, e.g. ENCLS, and may be propagated to userspace via errno.
> > + */
> > +
> > +#ifndef _UAPI_ASM_X86_SGX_ERRNO_H
> > +#define _UAPI_ASM_X86_SGX_ERRNO_H
> > +
> > +/**
> > + * enum sgx_encls_leaves - return codes for ENCLS, ENCLU and ENCLV
> > + * %SGX_SUCCESS:		No error.
> > + * %SGX_INVALID_SIG_STRUCT:	SIGSTRUCT contains an invalid value.
> > + * %SGX_INVALID_ATTRIBUTE:	Enclave is not attempting to access a resource
> 
> That first "not" looks wrong.
> 
> > + *				for which it is not authorized.
> > + * %SGX_BLKSTATE:		EPC page is already blocked.
> > + * %SGX_INVALID_MEASUREMENT:	SIGSTRUCT or EINITTOKEN contains an incorrect
> > + *				measurement.
> > + * %SGX_NOTBLOCKABLE:		EPC page type is not one which can be blocked.
> > + * %SGX_PG_INVLD:		EPC page is invalid (and cannot be blocked).
> > + * %SGX_EPC_PAGE_CONFLICT:	EPC page in use by another SGX instruction.
> > + * %SGX_INVALID_SIGNATURE:	Enclave's signature does not validate with
> > + *				public key enclosed in SIGSTRUCT.
> > + * %SGX_MAC_COMPARE_FAIL:	MAC check failed when reloading EPC page.
> > + * %SGX_PAGE_NOT_BLOCKED:	EPC page is not marked as blocked.
> > + * %SGX_NOT_TRACKED:		ETRACK has not been completed on the EPC page.
> > + * %SGX_VA_SLOT_OCCUPIED:	Version array slot contains a valid entry.
> > + * %SGX_CHILD_PRESENT:		Enclave has child pages present in the EPC.
> > + * %SGX_ENCLAVE_ACT:		Logical processors are currently executing
> > + *				inside the enclave.
> > + * %SGX_ENTRYEPOCH_LOCKED:	SECS locked for EPOCH update, i.e. an ETRACK is
> > + *				currently executing on the SECS.
> > + * %SGX_INVALID_EINITTOKEN:	EINITTOKEN is invalid and enclave signer's
> > + *				public key does not match IA32_SGXLEPUBKEYHASH.
> > + * %SGX_PREV_TRK_INCMPL:	All processors did not complete the previous
> > + *				tracking sequence.
> > + * %SGX_PG_IS_SECS:		Target EPC page is an SECS and cannot be
> > + *				blocked.
> > + * %SGX_PAGE_ATTRIBUTES_MISMATCH:	Attributes of the EPC page do not match
> > + *					the expected values.
> 
> You sometimes call it "PG" and sometimes "PAGE". Unify?
> 
> > + * %SGX_PAGE_NOT_MODIFIABLE:	EPC page cannot be modified because it is in
> > + *				the PENDING or MODIFIED state.
> > + * %SGX_PAGE_NOT_DEBUGGABLE:	EPC page cannot be modified because it is in
> > + *				the PENDING or MODIFIED state.
> 
> Same description text?

Thanks for the remarks. I think I define only the error codes in the
next version that actually get used by the driver and document them
properly. Should become way more cleaner.

/Jarkko