[PATCH v2 net-next 1/2] net: enetc: fix sleeping function called from rcu_read_lock() context

[Wei Fang <wei.fang@nxp.com>]

The rcu_read_lock() has been introduced in __ethtool_get_ts_info() since
the commit 4c61d809cf60 ("net: ethtool: Fix suspicious rcu_dereference
usage"). Therefore, the device drivers cannot use any sleeping functions
when implementing the callback of ethtool_ops::get_ts_info(). Currently,
pci_get_slot() is used in enetc_get_ts_info(), but it calls down_read()
which might sleep, so this is a potential issue. Therefore, to fix this
issue, pci_get_domain_bus_and_slot() is used to replace pci_get_slot()
in enetc_get_ts_info().

Reported-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Closes: https://lore.kernel.org/netdev/20250918124823.t3xlzn7w2glzkhnx@skbuf/
Fixes: f5b9a1cde0a2 ("net: enetc: add PTP synchronization support for ENETC v4")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
---
 drivers/net/ethernet/freescale/enetc/enetc_ethtool.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
index 6215e9c68fc5..445bfd032e0f 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
@@ -895,7 +895,8 @@ static int enetc4_get_phc_index_by_pdev(struct enetc_si *si)
 		return -1;
 	}
 
-	timer_pdev = pci_get_slot(bus, devfn);
+	timer_pdev = pci_get_domain_bus_and_slot(pci_domain_nr(bus),
+						 bus->number, devfn);
 	if (!timer_pdev)
 		return -1;
 
-- 
2.34.1