From: Keir Fraser <keir.fraser@citrix.com>
Date: Mon, 8 Feb 2010 10:18:14 +0000 (+0000)
Subject: Don't scrub broken pages
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~12630
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=407b049aebf00b916e2b196c444a6a79ea064fd5;p=xen.git

Don't scrub broken pages

Don't touch the poison pages when scrub the pages. Consuming poison
page will contaminate the CPU context and may cause system crash.

Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com>
---

diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index 0e1925a3bb..735c207e80 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -1256,6 +1256,9 @@ void scrub_one_page(struct page_info *pg)
 {
     void *p = __map_domain_page(pg);
 
+    if ( unlikely(pg->count_info & PGC_broken) )
+        return;
+
 #ifndef NDEBUG
     /* Avoid callers relying on allocations returning zeroed pages. */
     memset(p, 0xc2, PAGE_SIZE);