qeth: avoid duplicate deletion of multicast addresses

if qeth_set_multicast_list() is performed on 2 CPUs in parallel,
card->ip_list may end corrupted.
Solution: In function __qeth_delete_all_mc()
          remove card->ip_list entry before invoking
          qeth_deregister_addr_entry(). Thus a 2nd invocation of
          qeth_set_multicast_list() cannot try to remove the
          same entry twice.

Signed-off-by Ursula Braun <braunu@de.ibm.com>

Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/s390/net/qeth_main.c b/drivers/s390/net/qeth_main.c
index fe61647..6d7b79e 100644 (file)
--- a/drivers/s390/net/qeth_main.c
+++ b/drivers/s390/net/qeth_main.c
@@ -823,14 +823,15 @@ __qeth_delete_all_mc(struct qeth_card *card, unsigned long *flags)
 again:
        list_for_each_entry_safe(addr, tmp, &card->ip_list, entry) {
                if (addr->is_multicast) {
+                       list_del(&addr->entry);
                        spin_unlock_irqrestore(&card->ip_lock, *flags);
                        rc = qeth_deregister_addr_entry(card, addr);
                        spin_lock_irqsave(&card->ip_lock, *flags);
                        if (!rc) {
-                               list_del(&addr->entry);
                                kfree(addr);
                                goto again;
-                       }
+                       } else
+                               list_add(&addr->entry, &card->ip_list);
                }
        }
 }