From: Dave Hansen <dave.hansen@intel.com>
To: Reinette Chatre <reinette.chatre@intel.com>,
dave.hansen@linux.intel.com, jarkko@kernel.org,
linux-sgx@vger.kernel.org
Cc: haitao.huang@intel.com
Subject: Re: [RFC PATCH 0/4] SGX shmem backing store issue
Date: Wed, 4 May 2022 16:05:16 -0700 [thread overview]
Message-ID: <f0d00588-08ea-2a0d-9436-0885fbce22a3@intel.com> (raw)
In-Reply-To: <d4b52482-2dd0-d5f1-bda9-e1d97883298d@intel.com>
On 5/4/22 15:13, Reinette Chatre wrote:
> - if (pcmd_page_empty) {
> + if (pcmd_page_empty && !pcmd_page_in_use(encl, pcmd_first_page)) {
> ida_free(&encl->pcmd_in_backing, PFN_DOWN(page_pcmd_off));
> sgx_encl_truncate_backing_page(encl, PFN_DOWN(page_pcmd_off));
> }
One other thing. The role of encl->lock here is very important.
Without it, two concurrent page faults could do their individual
memset(), each see !pcmd_page_empty, then decline to truncate the page.
Also, given the challenges here, I do think we should check the
pcmd_page after truncate to ensure it is still all zero's.
next prev parent reply other threads:[~2022-05-04 23:29 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-28 20:11 [RFC PATCH 0/4] SGX shmem backing store issue Reinette Chatre
2022-04-28 20:11 ` [RFC PATCH 1/4] x86/sgx: Do not free backing memory on ENCLS[ELDU] failure Reinette Chatre
2022-04-28 21:30 ` Dave Hansen
2022-04-28 22:20 ` Reinette Chatre
2022-04-28 22:53 ` Dave Hansen
2022-04-28 23:49 ` Reinette Chatre
2022-05-03 2:01 ` Kai Huang
2022-05-07 17:25 ` Jarkko Sakkinen
2022-05-09 17:17 ` Reinette Chatre
2022-05-10 0:36 ` Kai Huang
2022-05-11 10:26 ` Jarkko Sakkinen
2022-05-11 18:29 ` Haitao Huang
2022-05-11 22:00 ` Kai Huang
2022-05-12 21:14 ` Jarkko Sakkinen
2022-05-06 22:09 ` Jarkko Sakkinen
2022-04-28 20:11 ` [RFC PATCH 2/4] x86/sgx: Set dirty bit after modifying page contents Reinette Chatre
2022-04-28 21:40 ` Dave Hansen
2022-04-28 22:41 ` Reinette Chatre
2022-05-06 22:27 ` Jarkko Sakkinen
2022-05-06 22:40 ` Reinette Chatre
2022-05-07 18:01 ` Jarkko Sakkinen
2022-04-28 20:11 ` [RFC PATCH 3/4] x86/sgx: Obtain backing storage page with enclave mutex held Reinette Chatre
2022-04-28 21:58 ` Dave Hansen
2022-04-28 22:44 ` Reinette Chatre
2022-05-06 22:43 ` Jarkko Sakkinen
2022-04-28 20:11 ` [RFC PATCH 4/4] x86/sgx: Do not allocate backing pages when loading from backing store Reinette Chatre
2022-04-28 21:12 ` [RFC PATCH 0/4] SGX shmem backing store issue Dave Hansen
2022-04-29 18:50 ` Reinette Chatre
2022-04-29 19:45 ` Dave Hansen
2022-04-30 3:22 ` Reinette Chatre
2022-04-30 15:52 ` Reinette Chatre
2022-05-02 14:36 ` Dave Hansen
2022-05-02 17:11 ` Reinette Chatre
2022-05-02 21:33 ` Dave Hansen
2022-05-04 22:13 ` Reinette Chatre
2022-05-04 22:58 ` Dave Hansen
2022-05-04 23:36 ` Reinette Chatre
2022-05-04 23:50 ` Dave Hansen
2022-05-05 0:08 ` Reinette Chatre
2022-05-04 23:05 ` Dave Hansen [this message]
2022-05-07 17:46 ` Jarkko Sakkinen
2022-05-07 17:48 ` Jarkko Sakkinen
2022-05-09 17:09 ` Reinette Chatre
2022-05-10 22:28 ` Jarkko Sakkinen
2022-05-11 17:23 ` Reinette Chatre
2022-05-12 14:10 ` Jarkko Sakkinen
2022-04-28 21:29 ` Dave Hansen
2022-04-28 22:20 ` Reinette Chatre
2022-05-04 6:40 ` Jarkko Sakkinen
2022-05-05 6:09 ` Jarkko Sakkinen
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