On Tue, Dec 04, Jan Beulich wrote: > This looks necessary but insufficient - there's nothing really > preventing backend_changed() from being called more than once > for a given device (is simply the handler of xenbus watch). Hence > I think either that function needs to be guarded against multiple > execution (e.g. by removing the watch from that function itself, > if that's permitted by xenbus), or to properly deal with the > effects this has (including but probably not limited to the leaking > of be->mode).
If another watch does really trigger after the kfree(be) in xen_blkbk_remove(), wouldnt backend_changed access stale memory? So if that can really happen in practice, shouldnt the backend_watch be a separate allocation instead being contained within backend_info? Looking at unregister_xenbus_watch, it clears removes the watch from the list, so that process_msg will not see it anymore. Olaf -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
