From: Jan Beulich <jbeulich@suse.com>
Date: Fri, 23 Nov 2018 11:08:09 +0000 (+0100)
Subject: mm: disallow MEMF_no_refcount to be passed for domain-owned allocations
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=d13e07df79a1ee209dcbe02c52b59ced6210b826;p=people%2Froyger%2Fxen.git

mm: disallow MEMF_no_refcount to be passed for domain-owned allocations

When such pages get assigned to domains (and hence their ->tot_pages
not incremented accordingly) we would otherwise also need to suppress
decrementing the count when freeing those pages.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index 08ee8cfbb9..4a2cbda1db 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -2303,6 +2303,11 @@ struct page_info *alloc_domheap_pages(
 
     if ( memflags & MEMF_no_owner )
         memflags |= MEMF_no_refcount;
+    else if ( (memflags & MEMF_no_refcount) && d )
+    {
+        ASSERT(!(memflags & MEMF_no_refcount));
+        return NULL;
+    }
 
     if ( dma_bitsize && ((dma_zone = bits_to_zone(dma_bitsize)) < zone_hi) )
         pg = alloc_heap_pages(dma_zone + 1, zone_hi, order, memflags, d);