From: Gao feng <gaofeng@cn.fujitsu.com>
Date: Tue, 11 Oct 2011 16:08:11 +0000 (+0000)
Subject: netconsole: enable netconsole can make net_device refcnt incorrent
X-Git-Tag: v3.1~9^2~10
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d5123480b1d6f7d1a5fe1a13520cef88fb5d4c84;p=pandora-kernel.git

netconsole: enable netconsole can make net_device refcnt incorrent

There is no check if netconsole is enabled current.
so when exec echo 1 > enabled;
the reference of net_device will increment always.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index ed2a3977c6e7..e8882023576b 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -307,6 +307,11 @@ static ssize_t store_enabled(struct netconsole_target *nt,
 		return err;
 	if (enabled < 0 || enabled > 1)
 		return -EINVAL;
+	if (enabled == nt->enabled) {
+		printk(KERN_INFO "netconsole: network logging has already %s\n",
+				nt->enabled ? "started" : "stopped");
+		return -EINVAL;
+	}
 
 	if (enabled) {	/* 1 */