netdev - [PATCH net v1] mlxbf_gige: fix receive packet race condition

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220908202853.21725-1-davthompson@nvidia.com>
Date:   Thu, 8 Sep 2022 16:28:53 -0400
From:   David Thompson <davthompson@...dia.com>
To:     <davem@...emloft.net>, <edumazet@...gle.com>, <kuba@...nel.org>,
        <pabeni@...hat.com>
CC:     <netdev@...r.kernel.org>, <cai.huoqing@...ux.dev>, <brgl@...ev.pl>,
        <limings@...dia.com>, David Thompson <davthompson@...dia.com>,
        Asmaa Mnebhi <asmaa@...dia.com>
Subject: [PATCH net v1] mlxbf_gige: fix receive packet race condition

Under heavy traffic, the BF2 Gigabit interface can
become unresponsive for periods of time (several minutes)
before eventually recovering.  This is due to a possible
race condition in the mlxbf_gige_rx_packet function, where
the function exits with producer and consumer indices equal
but there are remaining packet(s) to be processed. In order
to prevent this situation, disable receive DMA during the
processing of received packets.

Fixes: f92e1869d74e ("Add Mellanox BlueField Gigabit Ethernet driver")
Reviewed-by: Asmaa Mnebhi <asmaa@...dia.com>
Signed-off-by: David Thompson <davthompson@...dia.com>
---
 drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c
index afa3b92a6905..1490fbc74169 100644
--- a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c
+++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_rx.c
@@ -299,6 +299,10 @@ int mlxbf_gige_poll(struct napi_struct *napi, int budget)
 
 	mlxbf_gige_handle_tx_complete(priv);
 
+	data = readq(priv->base + MLXBF_GIGE_RX_DMA);
+	data &= ~MLXBF_GIGE_RX_DMA_EN;
+	writeq(data, priv->base + MLXBF_GIGE_RX_DMA);
+
 	do {
 		remaining_pkts = mlxbf_gige_rx_packet(priv, &work_done);
 	} while (remaining_pkts && work_done < budget);
@@ -314,6 +318,10 @@ int mlxbf_gige_poll(struct napi_struct *napi, int budget)
 		data = readq(priv->base + MLXBF_GIGE_INT_MASK);
 		data &= ~MLXBF_GIGE_INT_MASK_RX_RECEIVE_PACKET;
 		writeq(data, priv->base + MLXBF_GIGE_INT_MASK);
+
+		data = readq(priv->base + MLXBF_GIGE_RX_DMA);
+		data |= MLXBF_GIGE_RX_DMA_EN;
+		writeq(data, priv->base + MLXBF_GIGE_RX_DMA);
 	}
 
 	return work_done;
-- 
2.30.1