[3.19.y-ckt stable] Patch "iommu/amd: Handle large pages correctly in free_pagetable" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    iommu/amd: Handle large pages correctly in free_pagetable

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.y-ckt4.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 67f7f216cf5cb4c992f2e763edd17c6ea59c5bfe Mon Sep 17 00:00:00 2001
From: Joerg Roedel <jroedel at suse.de>
Date: Thu, 18 Jun 2015 10:48:34 +0200
Subject: iommu/amd: Handle large pages correctly in free_pagetable

commit 0b3fff54bc01e8e6064d222a33e6fa7adabd94cd upstream.

Make sure that we are skipping over large PTEs while walking
the page-table tree.

Fixes: 5c34c403b723 ("iommu/amd: Fix memory leak in free_pagetable")
Signed-off-by: Joerg Roedel <jroedel at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/iommu/amd_iommu.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 9802485..0ecfa72 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1870,9 +1870,15 @@ static void free_pt_##LVL (unsigned long __pt)			\
 	pt = (u64 *)__pt;					\
 								\
 	for (i = 0; i < 512; ++i) {				\
+		/* PTE present? */				\
 		if (!IOMMU_PTE_PRESENT(pt[i]))			\
 			continue;				\
 								\
+		/* Large PTE? */				\
+		if (PM_PTE_LEVEL(pt[i]) == 0 ||			\
+		    PM_PTE_LEVEL(pt[i]) == 7)			\
+			continue;				\
+								\
 		p = (unsigned long)IOMMU_PTE_PAGE(pt[i]);	\
 		FN(p);						\
 	}							\
--
1.9.1