From: Jeff Moyer <jmoyer@redhat.com>
Date: Fri, 12 Aug 2005 02:23:50 +0000 (-0700)
Subject: [NETPOLL]: deadlock bugfix
X-Git-Tag: firefly_0821_release~42350^2~6
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a636e1357911afdea7c8344ee65f78d36caf3c16;p=firefly-linux-kernel-4.4.55.git

[NETPOLL]: deadlock bugfix

This fixes an obvious deadlock in the netpoll code.  netpoll_rx takes the
npinfo->rx_lock.  netpoll_rx is also the only caller of arp_reply (through
__netpoll_rx).  As such, it is not necessary to take this lock.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 895f3efc65aa..b9d9da082af2 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -353,11 +353,8 @@ static void arp_reply(struct sk_buff *skb)
 	struct sk_buff *send_skb;
 	struct netpoll *np = NULL;
 
-	spin_lock_irqsave(&npinfo->rx_lock, flags);
 	if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
 		np = npinfo->rx_np;
-	spin_unlock_irqrestore(&npinfo->rx_lock, flags);
-
 	if (!np)
 		return;