From: Stephen Hemminger <shemminger@osdl.org>
Date: Tue, 16 May 2006 22:02:12 +0000 (-0700)
Subject: [PKT_SCHED]: Potential jiffy wrap bug in dev_watchdog().
X-Git-Tag: v2.6.17-rc5~104^2~5
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=338f7566e5c26a9547e25d54863ae4e4e5c856d1;p=linux-2.6

[PKT_SCHED]: Potential jiffy wrap bug in dev_watchdog().

There is a potential jiffy wraparound bug in the transmit watchdog
that is easily avoided by using time_after().

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 31eb83717c..138ea92ed2 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -193,8 +193,10 @@ static void dev_watchdog(unsigned long arg)
 		    netif_running(dev) &&
 		    netif_carrier_ok(dev)) {
 			if (netif_queue_stopped(dev) &&
-			    (jiffies - dev->trans_start) > dev->watchdog_timeo) {
-				printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n", dev->name);
+			    time_after(jiffies, dev->trans_start + dev->watchdog_timeo)) {
+
+				printk(KERN_INFO "NETDEV WATCHDOG: %s: transmit timed out\n",
+				       dev->name);
 				dev->tx_timeout(dev);
 			}
 			if (!mod_timer(&dev->watchdog_timer, jiffies + dev->watchdog_timeo))