netdev - [PATCH net 03/15] can: c_can: c_can_handle_bus_err(): update statistics if skb allocation fails

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Message-ID: <20241202090040.1110280-4-mkl@pengutronix.de>
Date: Mon,  2 Dec 2024 09:55:37 +0100
From: Marc Kleine-Budde <mkl@...gutronix.de>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net,
	kuba@...nel.org,
	linux-can@...r.kernel.org,
	kernel@...gutronix.de,
	Dario Binacchi <dario.binacchi@...rulasolutions.com>,
	Marc Kleine-Budde <mkl@...gutronix.de>
Subject: [PATCH net 03/15] can: c_can: c_can_handle_bus_err(): update statistics if skb allocation fails

From: Dario Binacchi <dario.binacchi@...rulasolutions.com>

Ensure that the statistics are always updated, even if the skb
allocation fails.

Fixes: 4d6d26537940 ("can: c_can: fix {rx,tx}_errors statistics")
Signed-off-by: Dario Binacchi <dario.binacchi@...rulasolutions.com>
Link: https://patch.msgid.link/20241122221650.633981-2-dario.binacchi@amarulasolutions.com
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
---
 drivers/net/can/c_can/c_can_main.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/net/can/c_can/c_can_main.c b/drivers/net/can/c_can/c_can_main.c
index 511615dc3341..cc371d0c9f3c 100644
--- a/drivers/net/can/c_can/c_can_main.c
+++ b/drivers/net/can/c_can/c_can_main.c
@@ -1014,49 +1014,57 @@ static int c_can_handle_bus_err(struct net_device *dev,
 
 	/* propagate the error condition to the CAN stack */
 	skb = alloc_can_err_skb(dev, &cf);
-	if (unlikely(!skb))
-		return 0;
 
 	/* check for 'last error code' which tells us the
 	 * type of the last error to occur on the CAN bus
 	 */
-	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+	if (likely(skb))
+		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 
 	switch (lec_type) {
 	case LEC_STUFF_ERROR:
 		netdev_dbg(dev, "stuff error\n");
-		cf->data[2] |= CAN_ERR_PROT_STUFF;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_STUFF;
 		stats->rx_errors++;
 		break;
 	case LEC_FORM_ERROR:
 		netdev_dbg(dev, "form error\n");
-		cf->data[2] |= CAN_ERR_PROT_FORM;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_FORM;
 		stats->rx_errors++;
 		break;
 	case LEC_ACK_ERROR:
 		netdev_dbg(dev, "ack error\n");
-		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
+		if (likely(skb))
+			cf->data[3] = CAN_ERR_PROT_LOC_ACK;
 		stats->tx_errors++;
 		break;
 	case LEC_BIT1_ERROR:
 		netdev_dbg(dev, "bit1 error\n");
-		cf->data[2] |= CAN_ERR_PROT_BIT1;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_BIT1;
 		stats->tx_errors++;
 		break;
 	case LEC_BIT0_ERROR:
 		netdev_dbg(dev, "bit0 error\n");
-		cf->data[2] |= CAN_ERR_PROT_BIT0;
+		if (likely(skb))
+			cf->data[2] |= CAN_ERR_PROT_BIT0;
 		stats->tx_errors++;
 		break;
 	case LEC_CRC_ERROR:
 		netdev_dbg(dev, "CRC error\n");
-		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
+		if (likely(skb))
+			cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 		stats->rx_errors++;
 		break;
 	default:
 		break;
 	}
 
+	if (unlikely(!skb))
+		return 0;
+
 	netif_receive_skb(skb);
 	return 1;
 }
-- 
2.45.2