linux-kernel - guard against buggy poll() return value

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Message-Id: <200803081110.52126.mitov@issp.bas.bg>
Date:	Sat, 8 Mar 2008 11:10:51 +0200
From:	Marin Mitov <mitov@...p.bas.bg>
To:	linux-kernel@...r.kernel.org
Cc:	Jeff Garzik <jgarzik@...ox.com>
Subject: guard against buggy poll() return value

Hi all,

Looking in net/core/dev.c I see:

WARN_ON_ONCE(work > weight);

which is a guard against buggy net drivers returning
more work from their poll method than they should.

Few lines bellow a check is done:

if (unlikely(work == weight)) 

which excludes the buggy outcome. 
Should not it be changed to:

if (unlikely(work >= weight)) 

If you find it worth, here is a patch against 2.6.24.3.

Regards.

Marin Mitov

Signed-off-by: Marin Mitov <mitov@...p.bas.bg>
-------------------------------------------
--- a/net/core/dev.c	2008-03-08 10:37:50.000000000 +0200
+++ b/net/core/dev.c	2008-03-08 10:39:09.000000000 +0200
@@ -2207,7 +2207,7 @@ static void net_rx_action(struct softirq
 		 * still "owns" the NAPI instance and therefore can
 		 * move the instance around on the list at-will.
 		 */
-		if (unlikely(work == weight)) {
+		if (unlikely(work >= weight)) {
 			if (unlikely(napi_disable_pending(n)))
 				__napi_complete(n);
 			else

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