netdev - [net-next PATCH V2 1/3] net: adjust napi_consume

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20160310121530.3680.53329.stgit@firesoul>
Date:	Thu, 10 Mar 2016 13:15:31 +0100
From:	Jesper Dangaard Brouer <brouer@...hat.com>
To:	netdev@...r.kernel.org, "David S. Miller" <davem@...emloft.net>
Cc:	eugenia@...lanox.com, Alexander Duyck <alexander.duyck@...il.com>,
	alexei.starovoitov@...il.com, saeedm@...lanox.com,
	Jesper Dangaard Brouer <brouer@...hat.com>,
	gerlitz.or@...il.com
Subject: [net-next PATCH V2 1/3] net: adjust napi_consume_skb to handle
 none-NAPI callers

Some drivers reuse/share code paths that free SKBs between NAPI
and none-NAPI calls. Adjust napi_consume_skb to handle this
use-case.

Before, calls from netpoll (w/ IRQs disabled) was handled and
indicated with a budget zero indication.  Use the same zero
indication to handle calls not originating from NAPI/softirq.
Simply handled by using dev_consume_skb_any().

This adds an extra branch+call for the netpoll case (checking
in_irq() + irqs_disabled()), but that is okay as this is a slowpath.

Suggested-by: Alexander Duyck <aduyck@...antis.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@...hat.com>
---
 net/core/skbuff.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 7af7ec635d90..bc62baa54ceb 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -801,9 +801,9 @@ void napi_consume_skb(struct sk_buff *skb, int budget)
 	if (unlikely(!skb))
 		return;
 
-	/* if budget is 0 assume netpoll w/ IRQs disabled */
+	/* Zero budget indicate none-NAPI context called us, like netpoll */
 	if (unlikely(!budget)) {
-		dev_consume_skb_irq(skb);
+		dev_consume_skb_any(skb);
 		return;
 	}