From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>,
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: Thu, 1 Nov 2018 19:42:13 +0200 (EET) [thread overview]
Message-ID: <alpine.DEB.2.21.1811011940120.5456@jsakkine-mobl1> (raw)
In-Reply-To: <20181031213036.GA23089@linux.intel.com>
On Wed, 31 Oct 2018, Sean Christopherson wrote:
> 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.
>
Yeah, this would give stable behavior when vDSO functions are not
available.
Here's a question: if we implement this behavior, could be upstream
series without vDSO's first and after those changes have been landed
we would continue with the vDSO's?
/Jarkko
next prev parent reply other threads:[~2018-11-01 17:42 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
2018-10-31 21:35 ` Dave Hansen
2018-11-01 17:42 ` Jarkko Sakkinen [this message]
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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