Merge tag 'linux-can-fixes-for-4.14-20171019' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2017-10-19

this is a pull request of 11 patches for the upcoming 4.14 release.

There are 6 patches by ZHU Yi for the flexcan driver, that work around
the CAN error handling state transition problems found in various
incarnations of the flexcan IP core.

The patch by Colin Ian King fixes a potential NULL pointer deref in the
CAN broad cast manager (bcm). One patch by me replaces a direct deref of a RCU
protected pointer by rcu_access_pointer. My second patch adds missing
OOM error handling in af_can. A patch by Stefan Mätje for the esd_usb2
driver fixes the dlc in received RTR frames. And the last patch is by
Wolfgang Grandegger, it fixes a busy loop in the gs_usb driver in case
it runs out of TX contexts.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 98 insertions, 30 deletions

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 13f0f219d8aa..a13a4896a8bd 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -182,22 +182,23 @@
 /* FLEXCAN hardware feature flags
  *
  * Below is some version info we got:
- *    SOC   Version   IP-Version  Glitch- [TR]WRN_INT Memory err RTR re-
- *                                Filter? connected?  detection  ception in MB
- *   MX25  FlexCAN2  03.00.00.00     no        no         no        no
- *   MX28  FlexCAN2  03.00.04.00    yes       yes         no        no
- *   MX35  FlexCAN2  03.00.00.00     no        no         no        no
- *   MX53  FlexCAN2  03.00.00.00    yes        no         no        no
- *   MX6s  FlexCAN3  10.00.12.00    yes       yes         no       yes
- *   VF610 FlexCAN3  ?               no       yes        yes       yes?
+ *    SOC   Version   IP-Version  Glitch- [TR]WRN_INT IRQ Err Memory err RTR re-
+ *                                Filter? connected?  Passive detection  ception in MB
+ *   MX25  FlexCAN2  03.00.00.00     no        no         ?       no        no
+ *   MX28  FlexCAN2  03.00.04.00    yes       yes        no       no        no
+ *   MX35  FlexCAN2  03.00.00.00     no        no         ?       no        no
+ *   MX53  FlexCAN2  03.00.00.00    yes        no        no       no        no
+ *   MX6s  FlexCAN3  10.00.12.00    yes       yes        no       no       yes
+ *   VF610 FlexCAN3  ?               no       yes         ?      yes       yes?
  *
  * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
  */
-#define FLEXCAN_QUIRK_BROKEN_ERR_STATE	BIT(1) /* [TR]WRN_INT not connected */
+#define FLEXCAN_QUIRK_BROKEN_WERR_STATE	BIT(1) /* [TR]WRN_INT not connected */
 #define FLEXCAN_QUIRK_DISABLE_RXFG	BIT(2) /* Disable RX FIFO Global mask */
 #define FLEXCAN_QUIRK_ENABLE_EACEN_RRS	BIT(3) /* Enable EACEN and RRS bit in ctrl2 */
 #define FLEXCAN_QUIRK_DISABLE_MECR	BIT(4) /* Disable Memory error detection */
 #define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP	BIT(5) /* Use timestamp based offloading */
+#define FLEXCAN_QUIRK_BROKEN_PERR_STATE	BIT(6) /* No interrupt for error passive */
 
 /* Structure of the message buffer */
 struct flexcan_mb {
@@ -281,14 +282,17 @@ struct flexcan_priv {
 };
 
 static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
-	.quirks = FLEXCAN_QUIRK_BROKEN_ERR_STATE,
+	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE,
 };
 
-static const struct flexcan_devtype_data fsl_imx28_devtype_data;
+static const struct flexcan_devtype_data fsl_imx28_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE,
+};
 
 static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
-		FLEXCAN_QUIRK_USE_OFF_TIMESTAMP,
+		FLEXCAN_QUIRK_USE_OFF_TIMESTAMP | FLEXCAN_QUIRK_BROKEN_PERR_STATE,
 };
 
 static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
@@ -335,6 +339,22 @@ static inline void flexcan_write(u32 val, void __iomem *addr)
 }
 #endif
 
+static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)
+{
+	struct flexcan_regs __iomem *regs = priv->regs;
+	u32 reg_ctrl = (priv->reg_ctrl_default | FLEXCAN_CTRL_ERR_MSK);
+
+	flexcan_write(reg_ctrl, &regs->ctrl);
+}
+
+static inline void flexcan_error_irq_disable(const struct flexcan_priv *priv)
+{
+	struct flexcan_regs __iomem *regs = priv->regs;
+	u32 reg_ctrl = (priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_MSK);
+
+	flexcan_write(reg_ctrl, &regs->ctrl);
+}
+
 static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
 {
 	if (!priv->reg_xceiver)
@@ -713,6 +733,7 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 	struct flexcan_regs __iomem *regs = priv->regs;
 	irqreturn_t handled = IRQ_NONE;
 	u32 reg_iflag1, reg_esr;
+	enum can_state last_state = priv->can.state;
 
 	reg_iflag1 = flexcan_read(&regs->iflag1);
 
@@ -765,8 +786,10 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 		flexcan_write(reg_esr & FLEXCAN_ESR_ALL_INT, &regs->esr);
 	}
 
-	/* state change interrupt */
-	if (reg_esr & FLEXCAN_ESR_ERR_STATE)
+	/* state change interrupt or broken error state quirk fix is enabled */
+	if ((reg_esr & FLEXCAN_ESR_ERR_STATE) ||
+	    (priv->devtype_data->quirks & (FLEXCAN_QUIRK_BROKEN_WERR_STATE |
+	                                   FLEXCAN_QUIRK_BROKEN_PERR_STATE)))
 		flexcan_irq_state(dev, reg_esr);
 
 	/* bus error IRQ - handle if bus error reporting is activated */
@@ -774,6 +797,44 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 	    (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
 		flexcan_irq_bus_err(dev, reg_esr);
 
+	/* availability of error interrupt among state transitions in case
+	 * bus error reporting is de-activated and
+	 * FLEXCAN_QUIRK_BROKEN_PERR_STATE is enabled:
+	 *  +--------------------------------------------------------------+
+	 *  | +----------------------------------------------+ [stopped /  |
+	 *  | |                                              |  sleeping] -+
+	 *  +-+-> active <-> warning <-> passive -> bus off -+
+	 *        ___________^^^^^^^^^^^^_______________________________
+	 *        disabled(1)  enabled             disabled
+	 *
+	 * (1): enabled if FLEXCAN_QUIRK_BROKEN_WERR_STATE is enabled
+	 */
+	if ((last_state != priv->can.state) &&
+	    (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_PERR_STATE) &&
+	    !(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
+		switch (priv->can.state) {
+		case CAN_STATE_ERROR_ACTIVE:
+			if (priv->devtype_data->quirks &
+			    FLEXCAN_QUIRK_BROKEN_WERR_STATE)
+				flexcan_error_irq_enable(priv);
+			else
+				flexcan_error_irq_disable(priv);
+			break;
+
+		case CAN_STATE_ERROR_WARNING:
+			flexcan_error_irq_enable(priv);
+			break;
+
+		case CAN_STATE_ERROR_PASSIVE:
+		case CAN_STATE_BUS_OFF:
+			flexcan_error_irq_disable(priv);
+			break;
+
+		default:
+			break;
+		}
+	}
+
 	return handled;
 }
 
@@ -887,7 +948,7 @@ static int flexcan_chip_start(struct net_device *dev)
 	 * on most Flexcan cores, too. Otherwise we don't get
 	 * any error warning or passive interrupts.
 	 */
-	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_ERR_STATE ||
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_WERR_STATE ||
 	    priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
 		reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
 	else
diff --git a/drivers/net/can/usb/esd_usb2.c b/drivers/net/can/usb/esd_usb2.c
index be928ce62d32..9fdb0f0bfa06 100644
--- a/drivers/net/can/usb/esd_usb2.c
+++ b/drivers/net/can/usb/esd_usb2.c
@@ -333,7 +333,7 @@ static void esd_usb2_rx_can_msg(struct esd_usb2_net_priv *priv,
 		}
 
 		cf->can_id = id & ESD_IDMASK;
-		cf->can_dlc = get_can_dlc(msg->msg.rx.dlc);
+		cf->can_dlc = get_can_dlc(msg->msg.rx.dlc & ~ESD_RTR);
 
 		if (id & ESD_EXTID)
 			cf->can_id |= CAN_EFF_FLAG;
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index afcc1312dbaf..68ac3e88a8ce 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -375,6 +375,8 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 
 		gs_free_tx_context(txc);
 
+		atomic_dec(&dev->active_tx_urbs);
+
 		netif_wake_queue(netdev);
 	}
 
@@ -463,14 +465,6 @@ static void gs_usb_xmit_callback(struct urb *urb)
 			  urb->transfer_buffer_length,
 			  urb->transfer_buffer,
 			  urb->transfer_dma);
-
-	atomic_dec(&dev->active_tx_urbs);
-
-	if (!netif_device_present(netdev))
-		return;
-
-	if (netif_queue_stopped(netdev))
-		netif_wake_queue(netdev);
 }
 
 static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 88edac0f3e36..ecd5c703d11e 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -78,7 +78,7 @@ MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
 static struct kmem_cache *rcv_cache __read_mostly;
 
 /* table of registered CAN protocols */
-static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly;
+static const struct can_proto __rcu *proto_tab[CAN_NPROTO] __read_mostly;
 static DEFINE_MUTEX(proto_tab_lock);
 
 static atomic_t skbcounter = ATOMIC_INIT(0);
@@ -788,7 +788,7 @@ int can_proto_register(const struct can_proto *cp)
 
 	mutex_lock(&proto_tab_lock);
 
-	if (proto_tab[proto]) {
+	if (rcu_access_pointer(proto_tab[proto])) {
 		pr_err("can: protocol %d already registered\n", proto);
 		err = -EBUSY;
 	} else
@@ -812,7 +812,7 @@ void can_proto_unregister(const struct can_proto *cp)
 	int proto = cp->protocol;
 
 	mutex_lock(&proto_tab_lock);
-	BUG_ON(proto_tab[proto] != cp);
+	BUG_ON(rcu_access_pointer(proto_tab[proto]) != cp);
 	RCU_INIT_POINTER(proto_tab[proto], NULL);
 	mutex_unlock(&proto_tab_lock);
 
@@ -875,9 +875,14 @@ static int can_pernet_init(struct net *net)
 	spin_lock_init(&net->can.can_rcvlists_lock);
 	net->can.can_rx_alldev_list =
 		kzalloc(sizeof(struct dev_rcv_lists), GFP_KERNEL);
-
+	if (!net->can.can_rx_alldev_list)
+		goto out;
 	net->can.can_stats = kzalloc(sizeof(struct s_stats), GFP_KERNEL);
+	if (!net->can.can_stats)
+		goto out_free_alldev_list;
 	net->can.can_pstats = kzalloc(sizeof(struct s_pstats), GFP_KERNEL);
+	if (!net->can.can_pstats)
+		goto out_free_can_stats;
 
 	if (IS_ENABLED(CONFIG_PROC_FS)) {
 		/* the statistics are updated every second (timer triggered) */
@@ -892,6 +897,13 @@ static int can_pernet_init(struct net *net)
 	}
 
 	return 0;
+
+ out_free_can_stats:
+	kfree(net->can.can_stats);
+ out_free_alldev_list:
+	kfree(net->can.can_rx_alldev_list);
+ out:
+	return -ENOMEM;
 }
 
 static void can_pernet_exit(struct net *net)
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 47a8748d953a..13690334efa3 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -1493,13 +1493,14 @@ static int bcm_init(struct sock *sk)
 static int bcm_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
-	struct net *net = sock_net(sk);
+	struct net *net;
 	struct bcm_sock *bo;
 	struct bcm_op *op, *next;
 
-	if (sk == NULL)
+	if (!sk)
 		return 0;
 
+	net = sock_net(sk);
 	bo = bcm_sk(sk);
 
 	/* remove bcm_ops, timer, rx_unregister(), etc. */