From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Jethro Beekman <jethro@fortanix.com>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Andy Lutomirski <luto@amacapital.net>,
Andrew Lutomirski <luto@kernel.org>, X86 ML <x86@kernel.org>,
Platform Driver <platform-driver-x86@vger.kernel.org>,
"nhorman@redhat.com" <nhorman@redhat.com>,
"npmccallum@redhat.com" <npmccallum@redhat.com>,
"Ayoun, Serge" <serge.ayoun@intel.com>,
"shay.katz-zamir@intel.com" <shay.katz-zamir@intel.com>,
"linux-sgx@vger.kernel.org" <linux-sgx@vger.kernel.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v14 09/19] x86/mm: x86/sgx: Signal SEGV_SGXERR for #PFs w/ PF_SGX
Date: Wed, 31 Oct 2018 14:30:36 -0700 [thread overview]
Message-ID: <20181031213036.GA23089@linux.intel.com> (raw)
In-Reply-To: <2e7b81e1-818f-7d76-e2b4-793d9ec5d5a6@intel.com>
On Mon, Oct 01, 2018 at 03:03:30PM -0700, Dave Hansen wrote:
> On 10/01/2018 02:42 PM, Jethro Beekman wrote:
> >
> > 1) Even though the vDSO function exists, userspace may still call
> > `ENCLU[EENTER]` manually, so the fault handling as described in the
> > current patch should also be maintained.
>
> Why?
Circling back to this question, what if we take the easy way out and
simply signal SIGSEGV without an SGX-specific code? I.e. treat #PF
with X86_PF_SGX as an access error, no more no less. That should be
sufficient for userspace to function, albeit with a little more effort,
but presumably no more than would be needed to run on SGX1 hardware.
AFAIK there isn't a way to prevent userspace from manually invoking
EENTER, short of doing some really nasty text poking or PTE swizzling.
We could declare using EENTER as unsupported, but that seems like
cutting off the nose to spite the face. Supporting userspace EENTER
in a limited capacity would allow people to do whatever crazy tricks
they're wont to do without having to deal with absurd requests for
the vDSO interface.
If we go this route we could also add the vDSO stuff after basic SGX
support is in mainline, obviously with approval from the powers that
be.
next prev parent reply other threads:[~2018-10-31 21:30 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-25 13:06 [PATCH v14 00/19] Intel SGX1 support Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 01/19] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 02/19] x86/sgx: Architectural structures Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 03/19] x86/cpufeature: Add SGX and SGX_LC CPU features Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 04/19] x86/cpufeatures: Add SGX feature bits Jarkko Sakkinen
2018-09-25 16:48 ` Borislav Petkov
2018-09-26 11:11 ` Jarkko Sakkinen
2018-09-26 11:36 ` Borislav Petkov
2018-09-27 13:16 ` Jarkko Sakkinen
2018-09-27 13:51 ` Borislav Petkov
2018-09-27 14:52 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 05/19] x86/msr: Add SGX definitions to msr-index.h Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 06/19] x86/mm: x86/sgx: Add new 'PF_SGX' page fault error code bit Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 07/19] x86/fault: x86/mm/pkeys: relocate stale comment regarding OSPKE Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 08/19] signal: x86/sgx: Add SIGSEGV siginfo code for SGX EPCM fault Jarkko Sakkinen
2018-09-26 19:14 ` Sean Christopherson
2018-09-27 18:41 ` Eric W. Biederman
2018-09-25 13:06 ` [PATCH v14 09/19] x86/mm: x86/sgx: Signal SEGV_SGXERR for #PFs w/ PF_SGX Jarkko Sakkinen
2018-09-25 22:53 ` Andy Lutomirski
2018-09-26 17:35 ` Sean Christopherson
2018-09-26 18:12 ` Andy Lutomirski
2018-09-26 20:16 ` Dave Hansen
2018-09-26 20:44 ` Sean Christopherson
2018-09-26 20:49 ` Dave Hansen
2018-09-26 21:15 ` Andy Lutomirski
2018-09-26 21:45 ` Dave Hansen
2018-09-26 22:37 ` Andy Lutomirski
2018-09-27 14:21 ` Jarkko Sakkinen
2018-09-27 14:41 ` Andy Lutomirski
2018-09-27 13:56 ` Jarkko Sakkinen
2018-10-01 21:42 ` Jethro Beekman
2018-10-01 22:03 ` Dave Hansen
2018-10-31 21:30 ` Sean Christopherson [this message]
2018-10-31 21:35 ` Dave Hansen
2018-11-01 17:42 ` Jarkko Sakkinen
2018-11-01 17:44 ` Jarkko Sakkinen
2018-10-02 0:31 ` Jarkko Sakkinen
2018-10-01 14:29 ` Sean Christopherson
2018-10-01 14:41 ` Dave Hansen
2018-10-02 0:07 ` Jarkko Sakkinen
2018-09-27 13:42 ` Jarkko Sakkinen
2018-09-27 14:58 ` Dave Hansen
2018-09-27 15:39 ` Jarkko Sakkinen
2018-09-27 15:53 ` Dave Hansen
2018-09-27 13:14 ` Jarkko Sakkinen
2018-09-27 19:43 ` Eric W. Biederman
2018-09-28 12:17 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 10/19] x86/sgx: Detect Intel SGX Jarkko Sakkinen
2018-09-25 20:02 ` Randy Dunlap
2018-09-27 13:13 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 11/19] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2018-09-25 20:01 ` Randy Dunlap
2018-09-27 13:12 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 12/19] x86/sgx: Add data structures for tracking the EPC pages Jarkko Sakkinen
2018-09-25 20:00 ` Randy Dunlap
2018-09-27 13:11 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 13/19] x86/sgx: Enclave Page Cache (EPC) memory manager Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 14/19] x86/sgx: Add sgx_einit() for initializing enclaves Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 15/19] platform/x86: Intel SGX driver Jarkko Sakkinen
2018-10-04 18:01 ` Sean Christopherson
2018-10-05 11:32 ` Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 16/19] platform/x86: Add swapping functionality to the " Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 17/19] x86/sgx: Add a simple swapper for the EPC memory manager Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 18/19] platform/x86: ptrace() support for the SGX driver Jarkko Sakkinen
2018-09-25 13:06 ` [PATCH v14 19/19] x86/sgx: Driver documentation Jarkko Sakkinen
2018-09-25 13:27 ` Jonathan Corbet
2018-10-15 20:54 ` Pavel Machek
2018-10-17 23:45 ` Jarkko Sakkinen
2018-10-18 9:57 ` Pavel Machek
2018-10-19 23:59 ` Jarkko Sakkinen
2018-10-17 23:56 ` Dave Hansen
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