net: stmmac: fix incorrect rxq|txq_stats reference

commit 133466c3bbe1 ("net: stmmac: use per-queue 64 bit statistics
where necessary") caused one regression as found by Uwe, the backtrace
looks like:

	INFO: trying to register non-static key.
	The code is fine but needs lockdep annotation, or maybe
	you didn't initialize this object before use?
	turning off the locking correctness validator.
	CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc1-00449-g133466c3bbe1-dirty #21
	Hardware name: STM32 (Device Tree Support)
	 unwind_backtrace from show_stack+0x18/0x1c
	 show_stack from dump_stack_lvl+0x60/0x90
	 dump_stack_lvl from register_lock_class+0x98c/0x99c
	 register_lock_class from __lock_acquire+0x74/0x293c
	 __lock_acquire from lock_acquire+0x134/0x398
	 lock_acquire from stmmac_get_stats64+0x2ac/0x2fc
	 stmmac_get_stats64 from dev_get_stats+0x44/0x130
	 dev_get_stats from rtnl_fill_stats+0x38/0x120
	 rtnl_fill_stats from rtnl_fill_ifinfo+0x834/0x17f4
	 rtnl_fill_ifinfo from rtmsg_ifinfo_build_skb+0xc0/0x144
	 rtmsg_ifinfo_build_skb from rtmsg_ifinfo+0x50/0x88
	 rtmsg_ifinfo from __dev_notify_flags+0xc0/0xec
	 __dev_notify_flags from dev_change_flags+0x50/0x5c
	 dev_change_flags from ip_auto_config+0x2f4/0x1260
	 ip_auto_config from do_one_initcall+0x70/0x35c
	 do_one_initcall from kernel_init_freeable+0x2ac/0x308
	 kernel_init_freeable from kernel_init+0x1c/0x138
	 kernel_init from ret_from_fork+0x14/0x2c

The reason is the rxq|txq_stats structures are not what expected
because stmmac_open() -> __stmmac_open() the structure is overwritten
by "memcpy(&priv->dma_conf, dma_conf, sizeof(*dma_conf));"
This causes the well initialized syncp member of rxq|txq_stats is
overwritten unexpectedly as pointed out by Johannes and Uwe.

Fix this issue by moving rxq|txq_stats back to stmmac_extra_stats. For
SMP cache friendly, we also mark stmmac_txq_stats and stmmac_rxq_stats
as ____cacheline_aligned_in_smp.

Fixes: 133466c3bbe1 ("net: stmmac: use per-queue 64 bit statistics where necessary")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230917165328.3403-1-jszhang@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 16 insertions, 16 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index b7ac7abecdd3..6aa5c0556d22 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -548,14 +548,14 @@ static void stmmac_get_per_qstats(struct stmmac_priv *priv, u64 *data)
 
 	pos = data;
 	for (q = 0; q < tx_cnt; q++) {
-		struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[q];
+		struct stmmac_txq_stats *txq_stats = &priv->xstats.txq_stats[q];
 		struct stmmac_txq_stats snapshot;
 
 		data = pos;
 		do {
-			start = u64_stats_fetch_begin(&tx_q->txq_stats.syncp);
-			snapshot = tx_q->txq_stats;
-		} while (u64_stats_fetch_retry(&tx_q->txq_stats.syncp, start));
+			start = u64_stats_fetch_begin(&txq_stats->syncp);
+			snapshot = *txq_stats;
+		} while (u64_stats_fetch_retry(&txq_stats->syncp, start));
 
 		p = (char *)&snapshot + offsetof(struct stmmac_txq_stats, tx_pkt_n);
 		for (stat = 0; stat < STMMAC_TXQ_STATS; stat++) {
@@ -566,14 +566,14 @@ static void stmmac_get_per_qstats(struct stmmac_priv *priv, u64 *data)
 
 	pos = data;
 	for (q = 0; q < rx_cnt; q++) {
-		struct stmmac_rx_queue *rx_q = &priv->dma_conf.rx_queue[q];
+		struct stmmac_rxq_stats *rxq_stats = &priv->xstats.rxq_stats[q];
 		struct stmmac_rxq_stats snapshot;
 
 		data = pos;
 		do {
-			start = u64_stats_fetch_begin(&rx_q->rxq_stats.syncp);
-			snapshot = rx_q->rxq_stats;
-		} while (u64_stats_fetch_retry(&rx_q->rxq_stats.syncp, start));
+			start = u64_stats_fetch_begin(&rxq_stats->syncp);
+			snapshot = *rxq_stats;
+		} while (u64_stats_fetch_retry(&rxq_stats->syncp, start));
 
 		p = (char *)&snapshot + offsetof(struct stmmac_rxq_stats, rx_pkt_n);
 		for (stat = 0; stat < STMMAC_RXQ_STATS; stat++) {
@@ -637,14 +637,14 @@ static void stmmac_get_ethtool_stats(struct net_device *dev,
 
 	pos = j;
 	for (i = 0; i < rx_queues_count; i++) {
-		struct stmmac_rx_queue *rx_q = &priv->dma_conf.rx_queue[i];
+		struct stmmac_rxq_stats *rxq_stats = &priv->xstats.rxq_stats[i];
 		struct stmmac_rxq_stats snapshot;
 
 		j = pos;
 		do {
-			start = u64_stats_fetch_begin(&rx_q->rxq_stats.syncp);
-			snapshot = rx_q->rxq_stats;
-		} while (u64_stats_fetch_retry(&rx_q->rxq_stats.syncp, start));
+			start = u64_stats_fetch_begin(&rxq_stats->syncp);
+			snapshot = *rxq_stats;
+		} while (u64_stats_fetch_retry(&rxq_stats->syncp, start));
 
 		data[j++] += snapshot.rx_pkt_n;
 		data[j++] += snapshot.rx_normal_irq_n;
@@ -654,14 +654,14 @@ static void stmmac_get_ethtool_stats(struct net_device *dev,
 
 	pos = j;
 	for (i = 0; i < tx_queues_count; i++) {
-		struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[i];
+		struct stmmac_txq_stats *txq_stats = &priv->xstats.txq_stats[i];
 		struct stmmac_txq_stats snapshot;
 
 		j = pos;
 		do {
-			start = u64_stats_fetch_begin(&tx_q->txq_stats.syncp);
-			snapshot = tx_q->txq_stats;
-		} while (u64_stats_fetch_retry(&tx_q->txq_stats.syncp, start));
+			start = u64_stats_fetch_begin(&txq_stats->syncp);
+			snapshot = *txq_stats;
+		} while (u64_stats_fetch_retry(&txq_stats->syncp, start));
 
 		data[j++] += snapshot.tx_pkt_n;
 		data[j++] += snapshot.tx_normal_irq_n;