From: Dave Hansen <dave.hansen@intel.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>,
Andy Lutomirski <luto@amacapital.net>
Cc: 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: Mon, 1 Oct 2018 07:41:23 -0700 [thread overview]
Message-ID: <cbb46b99-2b1b-0adb-0201-65d1613f4107@intel.com> (raw)
In-Reply-To: <1538404143.30715.27.camel@intel.com>
On 10/01/2018 07:29 AM, Sean Christopherson 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?
>
> If we want to avoid having to install a signal handler then I'm pretty
> sure we'd need to fixup all #GPs and "bad access" #PFs that occur on
> EENTER or in the enclave, not just PF_SGX faults. SGX1 hardware takes
> a #GP instead of a #PF on EPCM faults, and SGX2 hardware allows enclaves
> to allocate/free/adjust EPC pages at runtime, e.g. an enclave runtime
> might want to intercept #PFs from within the enclave so that the enclave
> can dynamically grow its stack.
I think the technique Andy describes can be used for that as well. It
basically works for any case where we know which instructions will take
an exception (any exception), call the instruction from a fixed
location, and know the fault(s) it can throw.
To me, it's almost like turning these faulting instructions into mini
syscall instructions. They enter the kernel only when they need help,
though, instead of always.
next prev parent reply other threads:[~2018-10-01 14:41 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
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 [this message]
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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