diff options
| author | Tim Gardner <timg@tpi.com> | 2011-04-20 09:00:49 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-04-21 21:04:32 -0700 |
| commit | cb771838715b1c470bc5735bdae709b33b18e0ad (patch) | |
| tree | 9de4b9a992aa2a521bfba73b941310dd8e09ea60 | |
| parent | e74fbd030223e29d269f4be17e3dce6de38f4c28 (diff) | |
| download | linux-3.10-cb771838715b1c470bc5735bdae709b33b18e0ad.tar.gz linux-3.10-cb771838715b1c470bc5735bdae709b33b18e0ad.tar.bz2 linux-3.10-cb771838715b1c470bc5735bdae709b33b18e0ad.zip | |
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: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/atl1c/atl1c.h | 6 | ||||
| -rw-r--r-- | drivers/net/atl1c/atl1c_main.c | 14 |
2 files changed, 8 insertions, 12 deletions
diff --git a/drivers/net/atl1c/atl1c.h b/drivers/net/atl1c/atl1c.h index 7cb375e0e29..925929d764c 100644 --- a/drivers/net/atl1c/atl1c.h +++ b/drivers/net/atl1c/atl1c.h @@ -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; diff --git a/drivers/net/atl1c/atl1c_main.c b/drivers/net/atl1c/atl1c_main.c index 7d9d5067a65..a6e1c36e48e 100644 --- a/drivers/net/atl1c/atl1c_main.c +++ b/drivers/net/atl1c/atl1c_main.c @@ -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); } @@ -337,20 +337,16 @@ 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; } @@ -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); } |