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From: David Yang <mmyangfl@gmail.com>
To: netdev@vger.kernel.org
Cc: David Yang <mmyangfl@gmail.com>,
	Ajit Khaparde <ajit.khaparde@broadcom.com>,
	Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>,
	Somnath Kotur <somnath.kotur@broadcom.com>,
	Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Sathya Perla <sathya.perla@avagotech.com>,
	Padmanabh Ratnakar <padmanabh.ratnakar@avagotech.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH net] be2net: fix data race in be_get_new_eqd
Date: Mon, 19 Jan 2026 23:34:36 +0800	[thread overview]
Message-ID: <20260119153440.1440578-1-mmyangfl@gmail.com> (raw)

In be_get_new_eqd(), statistics of pkts, protected by u64_stats_sync, are
read and accumulated in ignorance of possible u64_stats_fetch_retry()
events. Before the commit in question, these statistics were retrieved
one by one directly from queues. Fix this by reading them into temporary
variables first.

Fixes: 209477704187 ("be2net: set interrupt moderation for Skyhawk-R using EQ-DB")
Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 drivers/net/ethernet/emulex/benet/be_main.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index 5bb31c8fab39..995c159003d7 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -2141,7 +2141,7 @@ static int be_get_new_eqd(struct be_eq_obj *eqo)
 	struct be_aic_obj *aic;
 	struct be_rx_obj *rxo;
 	struct be_tx_obj *txo;
-	u64 rx_pkts = 0, tx_pkts = 0;
+	u64 rx_pkts = 0, tx_pkts = 0, pkts;
 	ulong now;
 	u32 pps, delta;
 	int i;
@@ -2157,15 +2157,17 @@ static int be_get_new_eqd(struct be_eq_obj *eqo)
 	for_all_rx_queues_on_eq(adapter, eqo, rxo, i) {
 		do {
 			start = u64_stats_fetch_begin(&rxo->stats.sync);
-			rx_pkts += rxo->stats.rx_pkts;
+			pkts = rxo->stats.rx_pkts;
 		} while (u64_stats_fetch_retry(&rxo->stats.sync, start));
+		rx_pkts += pkts;
 	}
 
 	for_all_tx_queues_on_eq(adapter, eqo, txo, i) {
 		do {
 			start = u64_stats_fetch_begin(&txo->stats.sync);
-			tx_pkts += txo->stats.tx_reqs;
+			pkts = txo->stats.tx_reqs;
 		} while (u64_stats_fetch_retry(&txo->stats.sync, start));
+		tx_pkts += pkts;
 	}
 
 	/* Skip, if wrapped around or first calculation */
-- 
2.51.0


             reply	other threads:[~2026-01-19 15:35 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-19 15:34 David Yang [this message]
2026-01-19 21:13 ` [PATCH net] be2net: fix data race in be_get_new_eqd Vadim Fedorenko
2026-01-21  2:40 ` patchwork-bot+netdevbpf

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