Patch "xen/privcmd: Support correctly 64KB page granularity when mapping memory" has been added to the 4.9-stable tree

Patch "xen/privcmd: Support correctly 64KB page granularity when mapping memory" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    xen/privcmd: Support correctly 64KB page granularity when mapping memory

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xen-privcmd-support-correctly-64kb-page-granularity-when-mapping-memory.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 753c09b5652bb4fe53e2db648002ec64b32b8827 Mon Sep 17 00:00:00 2001
From: Julien Grall <julien.grall@arm.com>
Date: Wed, 31 May 2017 14:03:57 +0100
Subject: xen/privcmd: Support correctly 64KB page granularity when mapping memory

From: Julien Grall <julien.grall@arm.com>

commit 753c09b5652bb4fe53e2db648002ec64b32b8827 upstream.

Commit 5995a68 "xen/privcmd: Add support for Linux 64KB page granularity" did
not go far enough to support 64KB in mmap_batch_fn.

The variable 'nr' is the number of 4KB chunk to map. However, when Linux
is using 64KB page granularity the array of pages (vma->vm_private_data)
contain one page per 64KB. Fix it by incrementing st->index correctly.

Furthermore, st->va is not correctly incremented as PAGE_SIZE !=
XEN_PAGE_SIZE.

Fixes: 5995a68 ("xen/privcmd: Add support for Linux 64KB page granularity")
Reported-by: Feng Kan <fkan@apm.com>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/xen/privcmd.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -335,8 +335,8 @@ static int mmap_batch_fn(void *data, int
 				st->global_error = 1;
 		}
 	}
-	st->va += PAGE_SIZE * nr;
-	st->index += nr;
+	st->va += XEN_PAGE_SIZE * nr;
+	st->index += nr / XEN_PFN_PER_PAGE;
 
 	return 0;
 }


Patches currently in stable-queue which might be from julien.grall@arm.com are

queue-4.9/xen-privcmd-support-correctly-64kb-page-granularity-when-mapping-memory.patch