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Commit cb771838 authored by Tim Gardner's avatar Tim Gardner Committed by David S. Miller
Browse files

atl1c: Fix work event interrupt/task races 



The mechanism used to initiate work events from the interrupt
handler has a classic read/modify/write race between the interrupt
handler that sets the condition, and the worker task that reads and
clears the condition. Close these races by using atomic
bit fields.

Cc: stable@kernel.org
Cc: Jie Yang <jie.yang@atheros.com>
Signed-off-by: default avatarTim Gardner <tim.gardner@canonical.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e74fbd03

drivers/net/atl1c/atl1c.h

+3 −3
Original line number Diff line number Diff line
@@ -566,9 +566,9 @@ struct atl1c_adapter { 
#define __AT_TESTING        0x0001

#define __AT_RESETTING      0x0002

#define __AT_DOWN           0x0003

	u8 work_event;

#define ATL1C_WORK_EVENT_RESET 		0x01

#define ATL1C_WORK_EVENT_LINK_CHANGE	0x02

	unsigned long work_event;

#define	ATL1C_WORK_EVENT_RESET		0

#define	ATL1C_WORK_EVENT_LINK_CHANGE	1

	u32 msg_enable;



	bool have_msi;

drivers/net/atl1c/atl1c_main.c

+5 −9
Original line number Diff line number Diff line
@@ -325,7 +325,7 @@ static void atl1c_link_chg_event(struct atl1c_adapter *adapter) 
		}

	}



	adapter->work_event |= ATL1C_WORK_EVENT_LINK_CHANGE;

	set_bit(ATL1C_WORK_EVENT_LINK_CHANGE, &adapter->work_event);

	schedule_work(&adapter->common_task);

}
@@ -337,21 +337,17 @@ static void atl1c_common_task(struct work_struct *work) 
	adapter = container_of(work, struct atl1c_adapter, common_task);

	netdev = adapter->netdev;



	if (adapter->work_event & ATL1C_WORK_EVENT_RESET) {

		adapter->work_event &= ~ATL1C_WORK_EVENT_RESET;

	if (test_and_clear_bit(ATL1C_WORK_EVENT_RESET, &adapter->work_event)) {

		netif_device_detach(netdev);

		atl1c_down(adapter);

		atl1c_up(adapter);

		netif_device_attach(netdev);

		return;

	}



	if (adapter->work_event & ATL1C_WORK_EVENT_LINK_CHANGE) {

		adapter->work_event &= ~ATL1C_WORK_EVENT_LINK_CHANGE;

	if (test_and_clear_bit(ATL1C_WORK_EVENT_LINK_CHANGE,

		&adapter->work_event))

		atl1c_check_link_status(adapter);

}

	return;

}





static void atl1c_del_timer(struct atl1c_adapter *adapter)
@@ -369,7 +365,7 @@ static void atl1c_tx_timeout(struct net_device *netdev) 
	struct atl1c_adapter *adapter = netdev_priv(netdev);



	/* Do the reset outside of interrupt context */

	adapter->work_event |= ATL1C_WORK_EVENT_RESET;

	set_bit(ATL1C_WORK_EVENT_RESET, &adapter->work_event);

	schedule_work(&adapter->common_task);

}