From: Jan Beulich <jbeulich@suse.com>
Date: Wed, 6 Jun 2012 15:37:05 +0000 (+0100)
Subject: xen: fix page_list_splice()
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~8343
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=d4b4e22f2b94e5a5f9392f7db2c44b219966f9d0;p=xen.git

xen: fix page_list_splice()

Other than in __list_splice(), the first element's prev pointer
doesn't need adjustment here - it already is PAGE_LIST_NULL. Rather
than fixing the assignment (to formally match __list_splice()), simply
assert that this assignment is really unnecessary.

Reported-by: Jisoo Yang <jisooy@gmail.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>

Also assert that the prev pointers are both PAGE_LIST_NULL.

Signed-off-by: Keir Fraser <keir@xen.org>

Committed-by: Keir Fraser <keir@xen.org>
---

diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index 11381a1303..64a0cc15f2 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -270,7 +270,8 @@ page_list_splice(struct page_list_head *list, struct page_list_head *head)
     last = list->tail;
     at = head->next;
 
-    first->list.prev = page_to_pdx(head->next);
+    ASSERT(first->list.prev == PAGE_LIST_NULL);
+    ASSERT(first->list.prev == at->list.prev);
     head->next = first;
 
     last->list.next = page_to_pdx(at);