e1000: fix occasional panic on unload
Net drivers in general have an issue where timers fired
by mod_timer or work threads with schedule_work are running
outside of the rtnl_lock.
With no other lock protection these routines are vulnerable
to races with driver unload or reset paths.
The longer term solution to this might be a redesign with
safer locks being taken in the driver to guarantee no
reentrance, but for now a safe and effective fix is
to take the rtnl_lock in these routines.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 5b4c6c0..c88439d 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -521,8 +521,21 @@
e1000_clean_all_rx_rings(adapter);
}
+void e1000_reinit_safe(struct e1000_adapter *adapter)
+{
+ while (test_and_set_bit(__E1000_RESETTING, &adapter->flags))
+ msleep(1);
+ rtnl_lock();
+ e1000_down(adapter);
+ e1000_up(adapter);
+ rtnl_unlock();
+ clear_bit(__E1000_RESETTING, &adapter->flags);
+}
+
void e1000_reinit_locked(struct e1000_adapter *adapter)
{
+ /* if rtnl_lock is not held the call path is bogus */
+ ASSERT_RTNL();
WARN_ON(in_interrupt());
while (test_and_set_bit(__E1000_RESETTING, &adapter->flags))
msleep(1);
@@ -2247,7 +2260,10 @@
struct e1000_adapter,
phy_info_task);
struct e1000_hw *hw = &adapter->hw;
+
+ rtnl_lock();
e1000_phy_get_info(hw, &adapter->phy_info);
+ rtnl_unlock();
}
/**
@@ -2273,6 +2289,7 @@
struct net_device *netdev = adapter->netdev;
u32 tctl;
+ rtnl_lock();
if (atomic_read(&adapter->tx_fifo_stall)) {
if ((er32(TDT) == er32(TDH)) &&
(er32(TDFT) == er32(TDFH)) &&
@@ -2293,6 +2310,7 @@
mod_timer(&adapter->tx_fifo_stall_timer, jiffies + 1);
}
}
+ rtnl_unlock();
}
bool e1000_has_link(struct e1000_adapter *adapter)
@@ -3160,7 +3178,7 @@
struct e1000_adapter *adapter =
container_of(work, struct e1000_adapter, reset_task);
- e1000_reinit_locked(adapter);
+ e1000_reinit_safe(adapter);
}
/**