---

yaml
---
r: 97790
b: refs/heads/master
c: 6cfd53f
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6f09bdfc717a0e1a89a029001484d5a195faab64
+refs/heads/master: 6cfd53fc03670c7a544a56d441eb1a6cc800d72b

trunk/mm/nommu.c

@@ -104,21 +104,43 @@ EXPORT_SYMBOL(vmtruncate);
 unsigned int kobjsize(const void *objp)
 {
 	struct page *page;
+	int order = 0;
 
 	/*
 	 * If the object we have should not have ksize performed on it,
 	 * return size of 0
 	 */
-	if (!objp || (unsigned long)objp >= memory_end || !((page = virt_to_page(objp))))
+	if (!objp)
 		return 0;
 
+	if ((unsigned long)objp >= memory_end)
+		return 0;
+
+	page = virt_to_head_page(objp);
+	if (!page)
+		return 0;
+
+	/*
+	 * If the allocator sets PageSlab, we know the pointer came from
+	 * kmalloc().
+	 */
 	if (PageSlab(page))
 		return ksize(objp);
 
-	BUG_ON(page->index < 0);
-	BUG_ON(page->index >= MAX_ORDER);
+	/*
+	 * The ksize() function is only guaranteed to work for pointers
+	 * returned by kmalloc(). So handle arbitrary pointers, that we expect
+	 * always to be compound pages, here.
+	 */
+	if (PageCompound(page))
+		order = compound_order(page);
 
-	return (PAGE_SIZE << page->index);
+	/*
+	 * Finally, handle arbitrary pointers that don't set PageSlab.
+	 * Default to 0-order in the case when we're unable to ksize()
+	 * the object.
+	 */
+	return PAGE_SIZE << order;
 }
 
 /*