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From: Paul Barker <paul.barker.ct@bp.renesas.com>
To: Sergey Shtylyov <s.shtylyov@omp.ru>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Paolo Abeni <pabeni@redhat.com>,
	=?UTF-8?q?Niklas=20S=C3=B6derlund?= <niklas.soderlund+renesas@ragnatech.se>,
	Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Paul Barker <paul.barker.ct@bp.renesas.com>,
	Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>,
	Biju Das <biju.das.jz@bp.renesas.com>,
	YueHaibing <yuehaibing@huawei.com>,
	netdev@vger.kernel.org,
	linux-renesas-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [net PATCH v3 3/4] net: ravb: Fix GbEth jumbo packet RX checksum handling
Date: Tue, 16 Apr 2024 13:02:53 +0100
Message-Id: <20240416120254.2620-4-paul.barker.ct@bp.renesas.com>
In-Reply-To: <20240416120254.2620-1-paul.barker.ct@bp.renesas.com>
References: <20240416120254.2620-1-paul.barker.ct@bp.renesas.com>
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Sending a 7kB ping packet to the RZ/G2L in v6.9-rc2 causes the following
backtrace:

	WARNING: CPU: 0 PID: 0 at include/linux/skbuff.h:3127 skb_trim+0x30/0x38
	Hardware name: Renesas SMARC EVK based on r9a07g044l2 (DT)
	pc : skb_trim+0x30/0x38
	lr : ravb_rx_csum_gbeth+0x40/0x90
	Call trace:
	 skb_trim+0x30/0x38
	 ravb_rx_gbeth+0x56c/0x5cc
	 ravb_poll+0xa0/0x204
	 __napi_poll+0x38/0x17c

This is caused by ravb_rx_gbeth() calling ravb_rx_csum_gbeth() with the
wrong skb for a packet which spans multiple descriptors. To fix this,
use the correct skb.

Fixes: c2da9408579d ("ravb: Add Rx checksum offload support for GbEth")
Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
---
No changes v2->v3:
Changes v1->v2:
  * Trimmed the call trace in accordance with the docs [1].
  * Add Sergey's Reviewed-by tag.

[1]: https://docs.kernel.org/process/submitting-patches.html#backtraces-in-commit-messages

 drivers/net/ethernet/renesas/ravb_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 3b870926af14..6969cdeeb67a 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -843,7 +843,7 @@ static bool ravb_rx_gbeth(struct net_device *ndev, int *quota, int q)
 				priv->rx_1st_skb->protocol =
 					eth_type_trans(priv->rx_1st_skb, ndev);
 				if (ndev->features & NETIF_F_RXCSUM)
-					ravb_rx_csum_gbeth(skb);
+					ravb_rx_csum_gbeth(priv->rx_1st_skb);
 				napi_gro_receive(&priv->napi[q],
 						 priv->rx_1st_skb);
 				rx_packets++;
-- 
2.39.2