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From: Dave Hansen <dave.hansen@intel.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: "Christopherson, Sean J" <sean.j.christopherson@intel.com>,
	Andrew Lutomirski <luto@kernel.org>,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	X86 ML <x86@kernel.org>,
	Platform Driver <platform-driver-x86@vger.kernel.org>,
	nhorman@redhat.com, npmccallum@redhat.com, "Ayoun,
	Serge" <serge.ayoun@intel.com>,
	shay.katz-zamir@intel.com, 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, 26 Sep 2018 14:45:17 -0700	[thread overview]
Message-ID: <992b1d6d-cc0f-776f-d938-2a1f7cad52c8@intel.com> (raw)
In-Reply-To: <CALCETrXByb2UVuZ6AXUeOd8y90NAikbZuvdN3wf_TjHZ+CxNhA@mail.gmail.com>

On 09/26/2018 02:15 PM, Andy Lutomirski wrote:
> Could we perhaps have a little vDSO entry (or syscall, I suppose) that
> runs an enclave an returns an error code, and rig up the #PF handler
> to check if the error happened in the vDSO entry and fix it up rather
> than sending a signal?

Yeah, signals suck.

So, instead of doing the enclave entry instruction (EENTER is it?), the
app would do the vDSO call.  It would have some calling convention, like
"set %rax to 0 before entering".  Then, we just teach the page fault
handler about the %RIP in the vDSO that can fault and how to move one
instruction later, munge %RIP to a value that tells about the error,
then return from the fault.  It would basically be like the kernel
exception tables, but for userspace.  Right?

How would a syscall work, though?  I assume we can't just enter the
enclave from ring0.

  reply	other threads:[~2018-09-26 21:45 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 [this message]
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
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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