From: Eric W. Biederman <ebiederm@xmission.com>
Date: Fri, 19 Feb 2010 13:23:47 +0000 (+0000)
Subject: net-sysfs: Use rtnl_trylock in wireless sysfs methods.
X-Git-Tag: firefly_0821_release~10186^2~2138
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9c42239c50d46364aecf2d5b6a927464a52e2723;p=firefly-linux-kernel-4.4.55.git

net-sysfs: Use rtnl_trylock in wireless sysfs methods.

[ Upstream commit b8afe6416101549e877f8470f2a160df69676166 ]

The wireless sysfs methods like the rest of the networking sysfs
methods are removed with the rtnl_lock held and block until
the existing methods stop executing.  So use rtnl_trylock
and restart_syscall so that the code continues to work.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 427ded841224..d5617d45deef 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -366,7 +366,8 @@ static ssize_t wireless_show(struct device *d, char *buf,
 	const struct iw_statistics *iw;
 	ssize_t ret = -EINVAL;
 
-	rtnl_lock();
+	if (!rtnl_trylock())
+		return restart_syscall();
 	if (dev_isalive(dev)) {
 		iw = get_wireless_stats(dev);
 		if (iw)