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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Ciara Loftus <ciara.loftus@intel.com>,
	Andrew Bowers <andrewx.bowers@intel.com>,
	Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
	Sasha Levin <sashal@kernel.org>,
	intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 20/40] ixgbe: protect ring accesses with READ- and WRITE_ONCE
Date: Wed,  1 Jul 2020 21:23:41 -0400	[thread overview]
Message-ID: <20200702012402.2701121-20-sashal@kernel.org> (raw)
In-Reply-To: <20200702012402.2701121-1-sashal@kernel.org>

From: Ciara Loftus <ciara.loftus@intel.com>

[ Upstream commit f140ad9fe2ae16f385f8fe4dc9cf67bb4c51d794 ]

READ_ONCE should be used when reading rings prior to accessing the
statistics pointer. Introduce this as well as the corresponding WRITE_ONCE
usage when allocating and freeing the rings, to ensure protected access.

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c  | 12 ++++++------
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 14 +++++++++++---
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
index cc3196ae5aea8..636e6e840afa2 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
@@ -923,7 +923,7 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter,
 		ring->queue_index = txr_idx;
 
 		/* assign ring to adapter */
-		adapter->tx_ring[txr_idx] = ring;
+		WRITE_ONCE(adapter->tx_ring[txr_idx], ring);
 
 		/* update count and index */
 		txr_count--;
@@ -950,7 +950,7 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter,
 		set_ring_xdp(ring);
 
 		/* assign ring to adapter */
-		adapter->xdp_ring[xdp_idx] = ring;
+		WRITE_ONCE(adapter->xdp_ring[xdp_idx], ring);
 
 		/* update count and index */
 		xdp_count--;
@@ -993,7 +993,7 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter,
 		ring->queue_index = rxr_idx;
 
 		/* assign ring to adapter */
-		adapter->rx_ring[rxr_idx] = ring;
+		WRITE_ONCE(adapter->rx_ring[rxr_idx], ring);
 
 		/* update count and index */
 		rxr_count--;
@@ -1022,13 +1022,13 @@ static void ixgbe_free_q_vector(struct ixgbe_adapter *adapter, int v_idx)
 
 	ixgbe_for_each_ring(ring, q_vector->tx) {
 		if (ring_is_xdp(ring))
-			adapter->xdp_ring[ring->queue_index] = NULL;
+			WRITE_ONCE(adapter->xdp_ring[ring->queue_index], NULL);
 		else
-			adapter->tx_ring[ring->queue_index] = NULL;
+			WRITE_ONCE(adapter->tx_ring[ring->queue_index], NULL);
 	}
 
 	ixgbe_for_each_ring(ring, q_vector->rx)
-		adapter->rx_ring[ring->queue_index] = NULL;
+		WRITE_ONCE(adapter->rx_ring[ring->queue_index], NULL);
 
 	adapter->q_vector[v_idx] = NULL;
 	napi_hash_del(&q_vector->napi);
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index edaa0bffa5c35..5336bfcd2d701 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -7064,7 +7064,10 @@ void ixgbe_update_stats(struct ixgbe_adapter *adapter)
 	}
 
 	for (i = 0; i < adapter->num_rx_queues; i++) {
-		struct ixgbe_ring *rx_ring = adapter->rx_ring[i];
+		struct ixgbe_ring *rx_ring = READ_ONCE(adapter->rx_ring[i]);
+
+		if (!rx_ring)
+			continue;
 		non_eop_descs += rx_ring->rx_stats.non_eop_descs;
 		alloc_rx_page += rx_ring->rx_stats.alloc_rx_page;
 		alloc_rx_page_failed += rx_ring->rx_stats.alloc_rx_page_failed;
@@ -7085,15 +7088,20 @@ void ixgbe_update_stats(struct ixgbe_adapter *adapter)
 	packets = 0;
 	/* gather some stats to the adapter struct that are per queue */
 	for (i = 0; i < adapter->num_tx_queues; i++) {
-		struct ixgbe_ring *tx_ring = adapter->tx_ring[i];
+		struct ixgbe_ring *tx_ring = READ_ONCE(adapter->tx_ring[i]);
+
+		if (!tx_ring)
+			continue;
 		restart_queue += tx_ring->tx_stats.restart_queue;
 		tx_busy += tx_ring->tx_stats.tx_busy;
 		bytes += tx_ring->stats.bytes;
 		packets += tx_ring->stats.packets;
 	}
 	for (i = 0; i < adapter->num_xdp_queues; i++) {
-		struct ixgbe_ring *xdp_ring = adapter->xdp_ring[i];
+		struct ixgbe_ring *xdp_ring = READ_ONCE(adapter->xdp_ring[i]);
 
+		if (!xdp_ring)
+			continue;
 		restart_queue += xdp_ring->tx_stats.restart_queue;
 		tx_busy += xdp_ring->tx_stats.tx_busy;
 		bytes += xdp_ring->stats.bytes;
-- 
2.25.1


  parent reply	other threads:[~2020-07-02  1:33 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200702012402.2701121-1-sashal@kernel.org>
2020-07-02  1:23 ` [PATCH AUTOSEL 5.4 12/40] net: usb: ax88179_178a: fix packet alignment padding Sasha Levin
2020-07-02  1:23 ` [PATCH AUTOSEL 5.4 17/40] net: ethernet: mvneta: Fix Serdes configuration for SoCs without comphy Sasha Levin
2020-07-02  1:23 ` [PATCH AUTOSEL 5.4 18/40] net: ethernet: mvneta: Add 2500BaseX support " Sasha Levin
2020-07-02  1:23 ` [PATCH AUTOSEL 5.4 19/40] tg3: driver sleeps indefinitely when EEH errors exceed eeh_max_freezes Sasha Levin
2020-07-02  1:23 ` Sasha Levin [this message]
2020-07-02  1:23 ` [PATCH AUTOSEL 5.4 21/40] i40e: protect ring accesses with READ- and WRITE_ONCE Sasha Levin
2020-07-02  1:23 ` [PATCH AUTOSEL 5.4 22/40] ibmvnic: continue to init in CRQ reset returns H_CLOSED Sasha Levin
2020-07-02  1:23 ` [PATCH AUTOSEL 5.4 24/40] usbnet: smsc95xx: Fix use-after-free after removal Sasha Levin

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