From: Keir Fraser <keir.fraser@citrix.com>
Date: Thu, 6 Dec 2007 10:43:24 +0000 (+0000)
Subject: Changed vm_normal_page to return NULL when presented with a VMA marked
X-Git-Tag: xen-3.2.0~21^2^2~28^2^2~18
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=95facbc26dc16bc6c815908977b7d37fbef41c1c;p=xenclient%2Fkernel.git

Changed vm_normal_page to return NULL when presented with a VMA marked
as being VM_FOREIGN.

Signed-off-by: Derek Murray <Derek.Murray@cl.cam.ac.uk>
---

diff --git a/mm/memory.c b/mm/memory.c
index 92aabca9..ceb0d351 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -396,6 +396,10 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_
 			return NULL;
 	}
 
+	/* XEN: Covers user-space grant mappings (even of local pages). */
+	if (unlikely(vma->vm_flags & VM_FOREIGN))
+		return NULL;
+
 	/*
 	 * Add some anal sanity checks for now. Eventually,
 	 * we should just do "return pfn_to_page(pfn)", but