Merge tag 'lsk-v4.4-16.06-android'

[firefly-linux-kernel-4.4.55.git] / drivers / xen / balloon.c

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 12eab503efd1bb8793fff55eca83649e1f564426..364bc44610c155db1b0217da931c47dd2b97a4e7 100644 (file)
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -152,6 +152,8 @@ static DECLARE_WAIT_QUEUE_HEAD(balloon_wq);
 static void balloon_process(struct work_struct *work);
 static DECLARE_DELAYED_WORK(balloon_worker, balloon_process);
 
+static void release_memory_resource(struct resource *resource);
+
 /* When ballooning out (allocating memory to return to Xen) we don't really
    want the kernel to try too hard since that can trigger the oom killer. */
 #define GFP_BALLOON \
@@ -268,6 +270,20 @@ static struct resource *additional_memory_resource(phys_addr_t size)
                return NULL;
        }
 
+#ifdef CONFIG_SPARSEMEM
+       {
+               unsigned long limit = 1UL << (MAX_PHYSMEM_BITS - PAGE_SHIFT);
+               unsigned long pfn = res->start >> PAGE_SHIFT;
+
+               if (pfn > limit) {
+                       pr_err("New System RAM resource outside addressable RAM (%lu > %lu)\n",
+                              pfn, limit);
+                       release_memory_resource(res);
+                       return NULL;
+               }
+       }
+#endif
+
        return res;
 }