mm: vmalloc allocator off by one

Fix off by one bug in the KVA allocator that can leave gaps in the address
space.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/vmalloc.c

@@ -362,7 +362,7 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
 				goto found;
 		}
 
-		while (addr + size >= first->va_start && addr + size <= vend) {
+		while (addr + size > first->va_start && addr + size <= vend) {
 			addr = ALIGN(first->va_end + PAGE_SIZE, align);
 
 			n = rb_next(&first->rb_node);