Re: [PATCH] panic during unregister_netdevice()

[Stephen Hemminger <shemminger@xxxxxxxx>]

Try this. Instead of dropping the last reference in unregister, it does it
after all other references are gone (sort of like the old 2.4 code).

diff -Nru a/net/core/dev.c b/net/core/dev.c
--- a/net/core/dev.c    Wed Nov  5 17:04:57 2003
+++ b/net/core/dev.c    Wed Nov  5 17:04:57 2003
@@ -2743,7 +2743,7 @@
        unsigned long rebroadcast_time, warning_time;
 
        rebroadcast_time = warning_time = jiffies;
-       while (atomic_read(&dev->refcnt) != 0) {
+       while (atomic_read(&dev->refcnt) > 1) {
                if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
                        rtnl_shlock();
                        rtnl_exlock();
@@ -2838,6 +2838,7 @@
                        dev->reg_state = NETREG_UNREGISTERED;
 
                        netdev_wait_allrefs(dev);
+                       dev_put(dev);
 
                        /* paranoia */
                        BUG_ON(atomic_read(&dev->refcnt));
@@ -2974,7 +2975,6 @@
        /* Finish processing unregister after unlock */
        net_set_todo(dev);
 
-       dev_put(dev);
        return 0;
 }