Messages in this thread Patch in this message | | | Date | Thu, 05 May 2011 17:10:44 -0700 | From | Greg KH <> | Subject | [patch 12/38] atl1c: Fix work event interrupt/task races |
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2.6.38-stable review patch. If anyone has any objections, please let us know.
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From: Tim Gardner <timg@tpi.com>
commit cb771838715b1c470bc5735bdae709b33b18e0ad upstream.
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: Jie Yang <jie.yang@atheros.com> Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/net/atl1c/atl1c.h | 6 +++--- drivers/net/atl1c/atl1c_main.c | 14 +++++--------- 2 files changed, 8 insertions(+), 12 deletions(-)
--- 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; --- 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 } } - 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 wor 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_ 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); }
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