Messages in this thread Patch in this message | | | From | Jia-Ju Bai <> | Subject | [PATCH] net: amd: xgbe: fix possible sleep-in-atomic-context bugs in xgbe_powerdown() | Date | Wed, 18 Dec 2019 22:01:02 +0800 |
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The driver may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is:
drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1261: flush_workqueue in xgbe_powerdown drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1253: _raw_spin_lock_irqsave in xgbe_powerdown
drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1055: napi_disable in xgbe_napi_disable drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1266: xgbe_napi_disable in xgbe_powerdown drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1253: _raw_spin_lock_irqsave in xgbe_powerdown
drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1049: napi_disable in xgbe_napi_disable drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1266: xgbe_napi_disable in xgbe_powerdown drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1253: _raw_spin_lock_irqsave in xgbe_powerdown
flush_workqueue() and napi_disable() can sleep at runtime.
To fix these bugs, flush_workqueue() and xgbe_napi_disable() are called without holding the spinlock.
These bugs are found by a static analysis tool STCheck written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index 98f8f2033154..328361d0e190 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -1257,17 +1257,18 @@ int xgbe_powerdown(struct net_device *netdev, unsigned int caller) netif_tx_stop_all_queues(netdev); xgbe_stop_timers(pdata); - flush_workqueue(pdata->dev_workqueue); hw_if->powerdown_tx(pdata); hw_if->powerdown_rx(pdata); - xgbe_napi_disable(pdata, 0); - pdata->power_down = 1; spin_unlock_irqrestore(&pdata->lock, flags); + flush_workqueue(pdata->dev_workqueue); + + xgbe_napi_disable(pdata, 0); + DBGPR("<--xgbe_powerdown\n"); return 0; -- 2.17.1
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