drivers/block/swim3.c: fix null pointer dereference

The use of pointer fs should be after the null check.

Signed-off-by: Cong Ding <dinggnu@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index 57763c5..758f2ac 100644 (file)
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -1090,10 +1090,13 @@ static const struct block_device_operations floppy_fops = {
 static void swim3_mb_event(struct macio_dev* mdev, int mb_state)
 {
        struct floppy_state *fs = macio_get_drvdata(mdev);
-       struct swim3 __iomem *sw = fs->swim3;
+       struct swim3 __iomem *sw;
 
        if (!fs)
                return;
+
+       sw = fs->swim3;
+
        if (mb_state != MB_FD)
                return;