Messages in this thread | | | Date | Fri, 9 Jan 2004 13:06:13 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH][SELINUX] 2/7 Add netif controls |
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James Morris <jmorris@redhat.com> wrote: > > +static void sel_netif_destroy(struct sel_netif *netif) > +{ > + DEBUGP("%s: %s\n", __FUNCTION__, netif->nsec.dev->name); > + > + spin_lock_bh(&sel_netif_lock); > + list_del_rcu(&netif->list); > + sel_netif_total--; > + spin_unlock_bh(&sel_netif_lock); > + > + call_rcu(&netif->rcu_head, sel_netif_free, netif); > +} > + > +void sel_netif_put(struct sel_netif *netif) > +{ > + if (atomic_dec_and_test(&netif->users)) > + sel_netif_destroy(netif); > +}
This seems racy. If the netif is still eligible for lookup on entry to sel_netif_put(), another CPU can come in and find the netif while it is hashed but while it has a zero refcount. Only to have the netif destroyed under its feet?
If so, you need to invent atomic_dec_and_lock_bh(). - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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