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Message-Id: <20241022172153.217890-1-jdamato@fastly.com>
Date: Tue, 22 Oct 2024 17:21:53 +0000
From: Joe Damato <jdamato@...tly.com>
To: netdev@...r.kernel.org
Cc: dmantipov@...dex.ru,
Joe Damato <jdamato@...tly.com>,
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: [RFC iwl-net] 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)
Hold RTNL in two places to fix this issue:
- e1000_reset_task
- __e1000_shutdown (which is called from both e1000_shutdown and
e1000_suspend).
The other paths which call e1000_down seemingly hold RTNL and are OK:
- e1000_close (ndo_stop)
- e1000_change_mtu (ndo_change_mtu)
I'm submitting this is as an RFC because:
- the e1000_reinit_locked issue appears very similar to commit
21f857f0321d ("e1000e: add rtnl_lock() to e1000_reset_task"), which
fixes a similar issue in e1000e
however
- adding rtnl to e1000_reinit_locked seemingly conflicts with an
earlier e1000 commit b2f963bfaeba ("e1000: fix lockdep warning in
e1000_reset_task").
Hopefully Intel can weigh in and shed some light on the correct way to
go.
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/
Signed-off-by: Joe Damato <jdamato@...tly.com>
---
drivers/net/ethernet/intel/e1000/e1000_main.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index 4de9b156b2be..9ed99c75d59e 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);
base-commit: d811ac148f0afd2f3f7e1cd7f54de8da973ec5e3
--
2.25.1
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