On Fri, Jul 07, 2017 at 12:33:34PM +0300, Dan Carpenter wrote: > Hello Johan Hovold, > > The patch 20777bc57c34: "NFC: fix broken device allocation" from Mar > 30, 2017, leads to the following static checker warning: > > drivers/nfc/pn533/pn533.c:2653 pn533_register_device() > error: 'priv->nfc_dev' dereferencing possible ERR_PTR()
> drivers/nfc/pn533/pn533.c > 2639 skb_queue_head_init(&priv->resp_q); > 2640 skb_queue_head_init(&priv->fragment_skb); > 2641 > 2642 INIT_LIST_HEAD(&priv->cmd_queue); > 2643 > 2644 priv->nfc_dev = nfc_allocate_device(&pn533_nfc_ops, protocols, > 2645 priv->ops->tx_header_len + > 2646 > PN533_CMD_DATAEXCH_HEAD_LEN, > 2647 priv->ops->tx_tail_len); > > We changed this to return error pointers as well as NULL. When > functions return a NULL as well as error pointers, then NULL is supposed > to be a special case of success but here it's just a failure. That's > messy and bug prone. Thanks for reporting this, Dan. I'll take a closer look at this tomorrow, but I guess we could just continue using NULL for all errors for now. Thanks, Johan
