[PATCH net] amd-xgbe: Use __napi_schedule() in BH context

[PATCH net] amd-xgbe: Use __napi_schedule() in BH context

[Sebastian Andrzej Siewior]

The driver uses __napi_schedule_irqoff() which is fine as long as it is
invoked with disabled interrupts by everybody. Since the commit
mentioned below the driver may invoke xgbe_isr_task() in tasklet/softirq
context. This may lead to list corruption if another driver uses
__napi_schedule_irqoff() in IRQ context.

Use __napi_schedule() which safe to use from IRQ and softirq context.

Fixes: 85b85c853401d ("amd-xgbe: Re-issue interrupt if interrupt status not cleared")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
---

Repost of
  https://lore.kernel.org/r/20191126222013.1904785-2-bigeasy@linutronix.de

+ Tom's Ack collected.

 drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
index b71f9b04a51e1..a87264f95f1a4 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
@@ -514,7 +514,7 @@ static void xgbe_isr_task(unsigned long data)
 				xgbe_disable_rx_tx_ints(pdata);
 
 				/* Turn on polling */
-				__napi_schedule_irqoff(&pdata->napi);
+				__napi_schedule(&pdata->napi);
 			}
 		} else {
 			/* Don't clear Rx/Tx status if doing per channel DMA
-- 
2.26.1

Re: [PATCH net] amd-xgbe: Use __napi_schedule() in BH context

[David Miller]

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 16 Apr 2020 17:57:40 +0200

> The driver uses __napi_schedule_irqoff() which is fine as long as it is
> invoked with disabled interrupts by everybody. Since the commit
> mentioned below the driver may invoke xgbe_isr_task() in tasklet/softirq
> context. This may lead to list corruption if another driver uses
> __napi_schedule_irqoff() in IRQ context.
> 
> Use __napi_schedule() which safe to use from IRQ and softirq context.
> 
> Fixes: 85b85c853401d ("amd-xgbe: Re-issue interrupt if interrupt status not cleared")
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Acked-by: Tom Lendacky <thomas.lendacky@amd.com>

Applied and queued up for -stable, thanks.