diff --git a/mm/slob.c b/mm/slob.c
index 5adc29c..03cce3d 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -190,6 +190,39 @@
 }
 EXPORT_SYMBOL(__kmalloc);
 
+/**
+ * krealloc - reallocate memory. The contents will remain unchanged.
+ *
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * The contents of the object pointed to are preserved up to the
+ * lesser of the new and old sizes.  If @p is %NULL, krealloc()
+ * behaves exactly like kmalloc().  If @size is 0 and @p is not a
+ * %NULL pointer, the object pointed to is freed.
+ */
+void *krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+	void *ret;
+
+	if (unlikely(!p))
+		return kmalloc_track_caller(new_size, flags);
+
+	if (unlikely(!new_size)) {
+		kfree(p);
+		return NULL;
+	}
+
+	ret = kmalloc_track_caller(new_size, flags);
+	if (ret) {
+		memcpy(ret, p, min(new_size, ksize(p)));
+		kfree(p);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(krealloc);
+
 void kfree(const void *block)
 {
 	bigblock_t *bb, **last = &bigblocks;
@@ -219,7 +252,7 @@
 
 EXPORT_SYMBOL(kfree);
 
-unsigned int ksize(const void *block)
+size_t ksize(const void *block)
 {
 	bigblock_t *bb;
 	unsigned long flags;