From: Dave Hansen <dave.hansen@intel.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Jethro Beekman <jethro@fortanix.com>,
Sean Christopherson <seanjc@google.com>,
reinette.chatre@intel.com, tony.luck@intel.com,
nathaniel@profian.com, stable@vger.kernel.org,
Borislav Petkov <bp@suse.de>,
linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/sgx: Free backing memory after faulting the enclave page
Date: Sun, 7 Nov 2021 11:58:21 -0800 [thread overview]
Message-ID: <dd7c1402-eeb9-cea5-25c6-ab19e8031991@intel.com> (raw)
In-Reply-To: <YYgs94O3eiKJwKgi@iki.fi>
On 11/7/21 11:45 AM, Jarkko Sakkinen wrote:
> On Sun, Nov 07, 2021 at 11:06:01AM -0800, Dave Hansen wrote:
>> That's true, the page cache should all be torn down along with the
>> fput(). *But*, it would be a very nice property if the backing storage
>> was empty by this point. It essentially ensures that no enclave-runtime
>> cases missed truncating the backing storage away.
>
> What if an enclave is released a point when all of its pages
> are swapped out? Or even simpler case would an enclave that is
> larger than all of EPC.
In this loop:
void sgx_encl_release(struct kref *ref)
{
...
xa_for_each(&encl->page_array, index, entry) {
if (entry->epc_page == NULL)
// truncate backing storage
> What can be made sure is that for all pages, which are in EPC,
> the backing page is truncated.
Right, and that should be utterly trivial to do.
prev parent reply other threads:[~2021-11-07 20:01 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-03 23:22 [PATCH] x86/sgx: Free backing memory after faulting the enclave page Jarkko Sakkinen
2021-11-04 13:50 ` Dave Hansen
2021-11-04 15:04 ` Jarkko Sakkinen
2021-11-04 15:09 ` Jarkko Sakkinen
2021-11-04 15:13 ` Dave Hansen
2021-11-04 15:25 ` Jarkko Sakkinen
2021-11-04 15:29 ` Dave Hansen
2021-11-07 19:42 ` Jarkko Sakkinen
2021-11-07 19:51 ` Dave Hansen
2021-11-07 22:28 ` Jarkko Sakkinen
2021-11-08 6:34 ` Dave Hansen
2021-11-08 20:07 ` Jarkko Sakkinen
2021-11-04 22:38 ` Dave Hansen
2021-11-07 18:06 ` Jarkko Sakkinen
2021-11-07 19:06 ` Dave Hansen
2021-11-07 19:45 ` Jarkko Sakkinen
2021-11-07 19:58 ` Dave Hansen [this message]
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