From: Reinette Chatre <reinette.chatre@intel.com>
To: Dave Hansen <dave.hansen@intel.com>, <linux-sgx@vger.kernel.org>,
<jarkko@kernel.org>, <shuah@kernel.org>
Cc: <seanjc@google.com>, <bp@alien8.de>,
<dave.hansen@linux.intel.com>, <linux-kselftest@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 12/14] selftests/sgx: Add page permission and exception test
Date: Thu, 16 Sep 2021 08:50:03 -0700 [thread overview]
Message-ID: <839c8954-8b95-1dc9-944c-eda4c95abc5a@intel.com> (raw)
In-Reply-To: <9990d737-9b9c-911f-3850-c9f3bc43c29b@intel.com>
Hi Dave,
On 9/16/2021 8:30 AM, Dave Hansen wrote:
> On 9/15/21 1:31 PM, Reinette Chatre wrote:
>> Add a test to ensure that (1) PTE permissions can be changed as long as
>> they do not exceed EPCM permissions, and (2) even if EPCM permissions
>> allow a page to be written to, if the PTE permissions do not then a #PF
>> should be generated when attempting to write to a (from PTE perspective)
>> read-only page.
>
> It took me a minute to figure out what this was trying to say.
The goal was to describe what features/functionalities are being tested.
You accurately point out that it is not clear how the test implemented
in the patch matches with these test goals.
> Maybe
> breaking it down into these three steps would help:
>
> Add a test that:
> (1) Creates an SGX enclave page with writable EPCM permission
> (2) Changes the PTE permission on the page to read-only. This should
> be permitted because the permission does not exceed the EPCM
> permission.
> (3) Attempts a write to the page and generate a page fault (#PF)
> because of the read-only PTE.
Thank you for the suggestion. What I understand from your feedback is
that I should mix the description of the actual test with what
features/functionalities are being tested. You do so in your suggestion
for (2) and to do the same for (3) I now plan to expand it to:
(3) Attempts a write to the page. This should generate a page fault
(#PF) because of the read-only PTE even though the EPCM
permissions allow the page to be written to.
Reinette
next prev parent reply other threads:[~2021-09-16 15:50 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-15 20:30 [PATCH 00/14] selftests/sgx: Oversubscription, page permission, thread entry Reinette Chatre
2021-09-15 20:30 ` [PATCH 01/14] selftests/x86/sgx: Fix a benign linker warning Reinette Chatre
2021-09-16 14:38 ` Jarkko Sakkinen
2021-09-16 14:39 ` Jarkko Sakkinen
2021-09-16 17:31 ` Reinette Chatre
2021-09-15 20:30 ` [PATCH 02/14] x86/sgx: Add /sys/kernel/debug/x86/sgx_total_mem Reinette Chatre
2021-09-16 14:09 ` Jarkko Sakkinen
2021-09-16 15:35 ` Reinette Chatre
2021-09-15 20:30 ` [PATCH 03/14] selftests/sgx: Assign source for each segment Reinette Chatre
2021-09-15 20:30 ` [PATCH 04/14] selftests/sgx: Make data measurement for an enclave segment optional Reinette Chatre
2021-09-15 20:30 ` [PATCH 05/14] selftests/sgx: Create a heap for the test enclave Reinette Chatre
2021-09-15 20:30 ` [PATCH 06/14] selftests/sgx: Dump segments and /proc/self/maps only on failure Reinette Chatre
2021-09-15 20:30 ` [PATCH 07/14] selftests/sgx: Encpsulate the test enclave creation Reinette Chatre
2021-09-15 20:30 ` [PATCH 08/14] selftests/sgx: Move setup_test_encl() to each TEST_F() Reinette Chatre
2021-09-15 20:30 ` [PATCH 09/14] selftests/sgx: Add a new kselftest: unclobbered_vdso_oversubscribed Reinette Chatre
2021-09-15 20:31 ` [PATCH 10/14] selftests/sgx: Provide per-op parameter structs for the test enclave Reinette Chatre
2021-09-15 20:31 ` [PATCH 11/14] selftests/sgx: Rename test properties in preparation for more enclave tests Reinette Chatre
2021-09-16 15:20 ` Jarkko Sakkinen
2021-09-15 20:31 ` [PATCH 12/14] selftests/sgx: Add page permission and exception test Reinette Chatre
2021-09-16 15:21 ` Jarkko Sakkinen
2021-09-16 15:37 ` Reinette Chatre
2021-09-16 15:30 ` Dave Hansen
2021-09-16 15:50 ` Reinette Chatre [this message]
2021-09-15 20:31 ` [PATCH 13/14] selftests/sgx: Enable multiple thread support Reinette Chatre
2021-09-16 15:23 ` Jarkko Sakkinen
2021-09-15 20:31 ` [PATCH 14/14] selftests/sgx: Add test for multiple TCS entry Reinette Chatre
2021-09-16 15:24 ` Jarkko Sakkinen
2021-09-16 14:13 ` [PATCH 00/14] selftests/sgx: Oversubscription, page permission, thread entry Jarkko Sakkinen
2021-09-16 15:37 ` Dave Hansen
2021-09-16 16:14 ` Reinette Chatre
2021-09-16 16:15 ` Jarkko Sakkinen
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