percpu: fix a memory leak in pcpu_extend_area_map()

The original code did not free the old map.  This patch fixes it.

tj: use @old as memcpy source instead of @chunk->map, and indentation
    and description update

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org

diff --git a/mm/percpu.c b/mm/percpu.c
index e61dc2c..a1830d8 100644 (file)
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -393,7 +393,9 @@ static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc)
                goto out_unlock;
 
        old_size = chunk->map_alloc * sizeof(chunk->map[0]);
-       memcpy(new, chunk->map, old_size);
+       old = chunk->map;
+
+       memcpy(new, old, old_size);
 
        chunk->map_alloc = new_alloc;
        chunk->map = new;