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Message-Id: <20241023172745.181265-1-jdamato@fastly.com>
Date: Wed, 23 Oct 2024 17:27:45 +0000
From: Joe Damato <jdamato@...tly.com>
To: netdev@...r.kernel.org
Cc: jacob.e.keller@...el.com,
Joe Damato <jdamato@...tly.com>,
Dmitry Antipov <dmantipov@...dex.ru>,
Tony Nguyen <anthony.l.nguyen@...el.com>,
Przemek Kitszel <przemyslaw.kitszel@...el.com>,
Andrew Lunn <andrew+netdev@...n.ch>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Simon Horman <horms@...nel.org>,
intel-wired-lan@...ts.osuosl.org (moderated list:INTEL ETHERNET DRIVERS),
linux-kernel@...r.kernel.org (open list)
Subject: [iwl-net v2] e1000: Hold RTNL when e1000_down can be called
e1000_down calls netif_queue_set_napi, which assumes that RTNL is held.
There are a few paths for e1000_down to be called in e1000 where RTNL is
not currently being held:
- e1000_shutdown (pci shutdown)
- e1000_suspend (power management)
- e1000_reinit_locked (via e1000_reset_task delayed work)
- e1000_io_error_detected (via pci error handler)
Hold RTNL in three places to fix this issue:
- e1000_reset_task: igc, igb, and e100e all hold rtnl in this path.
- e1000_io_error_detected (pci error handler): e1000e and ixgbe hold
rtnl in this path. A patch has been posted for igc to do the same
[1].
- __e1000_shutdown (which is called from both e1000_shutdown and
e1000_suspend): igb, ixgbe, and e1000e all hold rtnl in the same
path.
The other paths which call e1000_down seemingly hold RTNL and are OK:
- e1000_close (ndo_stop)
- e1000_change_mtu (ndo_change_mtu)
Based on the above analysis and mailing list discussion [2], I believe
adding rtnl in the three places mentioned above is correct.
Fixes: 8f7ff18a5ec7 ("e1000: Link NAPI instances to queues and IRQs")
Reported-by: Dmitry Antipov <dmantipov@...dex.ru>
Closes: https://lore.kernel.org/netdev/8cf62307-1965-46a0-a411-ff0080090ff9@yandex.ru/
Link: https://lore.kernel.org/netdev/20241022215246.307821-3-jdamato@fastly.com/ [1]
Link: https://lore.kernel.org/netdev/ZxgVRX7Ne-lTjwiJ@LQ3V64L9R2/ [2]
Signed-off-by: Joe Damato <jdamato@...tly.com>
---
v2:
- No longer an RFC
- Include an rtnl_lock/rtnl_unlock in e1000_io_error_detected
inspired by ixgbe's implementation of the same
drivers/net/ethernet/intel/e1000/e1000_main.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index 4de9b156b2be..3f089c3d47b2 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -3509,7 +3509,9 @@ static void e1000_reset_task(struct work_struct *work)
container_of(work, struct e1000_adapter, reset_task);
e_err(drv, "Reset adapter\n");
+ rtnl_lock();
e1000_reinit_locked(adapter);
+ rtnl_unlock();
}
/**
@@ -5074,7 +5076,9 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool *enable_wake)
usleep_range(10000, 20000);
WARN_ON(test_bit(__E1000_RESETTING, &adapter->flags));
+ rtnl_lock();
e1000_down(adapter);
+ rtnl_unlock();
}
status = er32(STATUS);
@@ -5235,16 +5239,20 @@ static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
struct net_device *netdev = pci_get_drvdata(pdev);
struct e1000_adapter *adapter = netdev_priv(netdev);
+ rtnl_lock();
netif_device_detach(netdev);
- if (state == pci_channel_io_perm_failure)
+ if (state == pci_channel_io_perm_failure) {
+ rtnl_unlock();
return PCI_ERS_RESULT_DISCONNECT;
+ }
if (netif_running(netdev))
e1000_down(adapter);
if (!test_and_set_bit(__E1000_DISABLED, &adapter->flags))
pci_disable_device(pdev);
+ rtnl_unlock();
/* Request a slot reset. */
return PCI_ERS_RESULT_NEED_RESET;
base-commit: d05596f248578be943015c1237120574a8d845dd
--
2.25.1
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