From: Eric W. Biederman <ebiederm@xmission.com>
Date: Tue, 1 Apr 2014 19:21:02 +0000 (-0700)
Subject: netpoll: Use skb_irq_freeable to make zap_completion_queue safe.
X-Git-Tag: v4.9.8~6652^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b1586f099ba897542ece36e8a23c1a62907261ef;p=platform%2Fkernel%2Flinux-rpi3.git

netpoll: Use skb_irq_freeable to make zap_completion_queue safe.

Replace the test in zap_completion_queue to test when it is safe to
free skbs in hard irq context with skb_irq_freeable ensuring we only
free skbs when it is safe, and removing the possibility of subtle
problems.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index ed7740f..e33937f 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -270,7 +270,7 @@ static void zap_completion_queue(void)
 		while (clist != NULL) {
 			struct sk_buff *skb = clist;
 			clist = clist->next;
-			if (skb->destructor) {
+			if (!skb_irq_freeable(skb)) {
 				atomic_inc(&skb->users);
 				dev_kfree_skb_any(skb); /* put this one back */
 			} else {