From: Jordan Hand <jorhand@linux.microsoft.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
linux-sgx@vger.kernel.org, akpm@linux-foundation.org,
dave.hansen@intel.com, nhorman@redhat.com, npmccallum@redhat.com,
haitao.huang@intel.com, andriy.shevchenko@linux.intel.com,
tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de,
josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com,
rientjes@google.com, cedric.xing@intel.com,
puiterwijk@redhat.com, linux-security-module@vger.kernel.org,
Suresh Siddha <suresh.b.siddha@intel.com>,
Haitao Huang <haitao.huang@linux.intel.com>
Subject: Re: [PATCH v26 10/22] x86/sgx: Linux Enclave Driver
Date: Thu, 20 Feb 2020 16:11:04 -0800 [thread overview]
Message-ID: <2c077197-a8a7-feac-58ea-e901c92fb58b@linux.microsoft.com> (raw)
In-Reply-To: <20200220221607.GB26618@linux.intel.com>
On 2/20/20 2:16 PM, Jarkko Sakkinen wrote:
> On Thu, Feb 20, 2020 at 10:48:42AM -0800, Sean Christopherson wrote:
>> My biggest concern for allowing PROT_EXEC if RIE is that it would result
>> in #PF(SGX) (#GP on Skylake) due to an EPCM violation if the enclave
>> actually tried to execute from such a page. This isn't a problem for the
>> kernel as the fault will be reported cleanly through the vDSO (or get
>> delivered as a SIGSEGV if the enclave isn't entered through the vDSO), but
>> it's a bit weird for userspace as userspace will see the #PF(SGX) and
>> likely assume the EPC was lost, e.g. silently restart the enclave instead
>> of logging an error that the enclave is broken.
>
> I think right way to fix the current implementation is to -EACCES mmap()
> (and mprotect) when !!(current->personality & READ_IMPLIES_EXEC).
>
I agree. It still means userspace code with an executable stack can't
mmap/mprotect enclave pages and request PROT_READ but the check you've
proposed would more consistently enforce this which is easier to
understand from userspace perspective.
-Jordan
next prev parent reply other threads:[~2020-02-21 0:11 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-09 21:25 [PATCH v26 00/22] Intel SGX foundations Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 01/22] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 02/22] x86/cpufeatures: x86/msr: Intel SGX Launch Control " Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 03/22] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 04/22] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 05/22] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 06/22] x86/cpu/intel: Detect SGX supprt Jarkko Sakkinen
2020-02-12 16:57 ` Sean Christopherson
2020-02-13 18:04 ` Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 07/22] x86/sgx: Enumerate and track EPC sections Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 08/22] x86/sgx: Add functions to allocate and free EPC pages Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 09/22] mm: Introduce vm_ops->may_mprotect() Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 10/22] x86/sgx: Linux Enclave Driver Jarkko Sakkinen
2020-02-13 13:59 ` Jethro Beekman
2020-02-13 18:07 ` Sean Christopherson
2020-02-14 9:24 ` Jethro Beekman
2020-02-14 17:11 ` Sean Christopherson
2020-02-14 17:40 ` Andy Lutomirski
2020-02-14 17:52 ` Sean Christopherson
2020-02-15 16:56 ` Andy Lutomirski
2020-02-18 22:12 ` Sean Christopherson
2020-02-15 18:05 ` Dr. Greg
2020-02-15 7:32 ` Jarkko Sakkinen
2020-02-15 7:35 ` Jarkko Sakkinen
2020-02-19 3:26 ` Jordan Hand
2020-02-20 18:13 ` Sean Christopherson
2020-02-20 18:33 ` Jordan Hand
2020-02-20 18:48 ` Sean Christopherson
2020-02-20 22:16 ` Jarkko Sakkinen
2020-02-21 0:11 ` Jordan Hand [this message]
2020-02-21 12:53 ` Jarkko Sakkinen
2020-02-21 0:32 ` Andy Lutomirski
2020-02-21 13:01 ` Jarkko Sakkinen
2020-02-20 18:51 ` Andy Lutomirski
2020-02-20 19:15 ` Sean Christopherson
2020-02-20 22:10 ` Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 11/22] selftests/x86: Recurse into subdirectories Jarkko Sakkinen
2020-02-09 21:25 ` [PATCH v26 12/22] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 13/22] x86/sgx: Add provisioning Jarkko Sakkinen
2020-02-13 10:49 ` Jethro Beekman
2020-02-15 7:25 ` Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 14/22] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 15/22] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 16/22] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 17/22] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 18/22] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 19/22] x86/vdso: Add __vdso_sgx_enter_enclave() to wrap SGX enclave transitions Jarkko Sakkinen
2020-02-13 13:29 ` Jethro Beekman
2020-02-15 7:26 ` Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 20/22] selftests/x86: Add vDSO selftest for SGX Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 21/22] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
2020-02-09 21:26 ` [PATCH v26 22/22] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-02-22 4:13 ` Randy Dunlap
2020-02-23 17:04 ` Jarkko Sakkinen
2020-02-23 17:05 ` Jarkko Sakkinen
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