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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: linux-sgx@vger.kernel.org
Subject: [PATCH] x86/sgx: Fix ELDU MAC failures
Date: Thu, 22 Aug 2019 19:00:02 -0700	[thread overview]
Message-ID: <20190823020002.25550-1-sean.j.christopherson@intel.com> (raw)

Revert a change that directly propagates the page type from SECINFO into
encl_page->desc.  encl_page->desc is a packed value, jamming the SECINFO
page_type sets bits that are intended for other uses.

Specifically, bits 11:3 are used to store the VA offset when a page is
swapped out and are available for other uses when the page is resident
in the EPC.  To allow overloading bits 11:3, the VA offset is cleared at
ELDU and so is not explicitly cleared at EWB, e.g. the VA offset is OR'd
into encl_page->desc.  As a result, a subsequent ELDU gets a MAC failure
due to loading the wrong VA offset.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kernel/cpu/sgx/driver/ioctl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/sgx/driver/ioctl.c b/arch/x86/kernel/cpu/sgx/driver/ioctl.c
index 85e36e530baf..355ce967a77f 100644
--- a/arch/x86/kernel/cpu/sgx/driver/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/driver/ioctl.c
@@ -140,7 +140,8 @@ static struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
 		return ERR_PTR(-ENOMEM);
 
 	encl_page->desc = addr;
-	encl_page->desc |= page_type;
+	if (page_type == SGX_SECINFO_TCS)
+		encl_page->desc |= SGX_ENCL_PAGE_TCS;
 	encl_page->encl = encl;
 
 	/* Calculate maximum of the VM flags for the page. */
-- 
2.22.0


             reply	other threads:[~2019-08-23  2:00 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-23  2:00 Sean Christopherson [this message]
2019-08-23 13:35 ` [PATCH] x86/sgx: Fix ELDU MAC failures Jarkko Sakkinen
2019-08-23 13:39   ` Jarkko Sakkinen
2019-08-23 13:54     ` Jarkko Sakkinen

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