[PATCH] ieee802154/at231rf230: deadlock in at86rf230_xmit

[Denis Efremov]

spin_lock(&lp->lock) is used in at86rf230_isr interrupt
handler and in at86rf230_xmit callback to protect
lp->irq_disabled. It seems that deadlock is possible,
because:
at86rf230_xmit
   spin_lock(&lp->lock); // acquired
// interrupt
at86rf230_isr
   spin_lock(&lp->lock); // deadlock

To prevent it, spin_lock_irq* should be used in xmit callback.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Denis Efremov <yefremov.denis@xxxxxxxxx>
---
 drivers/net/ieee802154/at86rf230.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
index a4a62e1..7c02dd9 100644
--- a/drivers/net/ieee802154/at86rf230.c
+++ b/drivers/net/ieee802154/at86rf230.c
@@ -543,12 +543,12 @@ at86rf230_xmit(struct ieee802154_dev *dev, struct sk_buff *skb)
 	int rc;
 	unsigned long flags;
 
-	spin_lock(&lp->lock);
+	spin_lock_irqsave(&lp->lock, flags);
 	if  (lp->irq_disabled) {
-		spin_unlock(&lp->lock);
+		spin_unlock_irqrestore(&lp->lock, flags);
 		return -EBUSY;
 	}
-	spin_unlock(&lp->lock);
+	spin_unlock_irqrestore(&lp->lock, flags);
 
 	might_sleep();
 
-- 
1.8.1.2

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