That is valid only if the drivers also comply. Eg if driver has two stack variables private_data and private_data_len, and it sets only private_data_len to zero. Then when calling the upper layer, it sets the event->private_data to its local private_data (uninitialized) and event->private_data_len to its local private_data_len (zero). Here we have to check the private_data_len before touching private_data or risk bug/panic.
thanks, - KK Tom Tucker <[EMAIL PROTECTED]> wrote on 11/10/2006 10:20:18 AM: > > If it's truly nul or a ptr, we don't need to (and shouldn't) check, just > call kfree. If it's unitialized, we can't tell anyway and it's a bug -- > right? > > Am I missing something? > > On 11/9/06 10:41 PM, "Krishna Kumar2" <[EMAIL PROTECTED]> wrote: > > > Though the amso driver (c2_ae_event) is setting the private_data and > > private_data_len together for connect request and connect result, so > > the check may not be necessary. But if the semantics prefer checking > > to make sure, we should follow that (esp if other future drivers may > > also simply set private_data_len to zero without modifying > > private_data). > > > > I did it this way since cm_conn_rep_handler() had the same check :) > > > > thanks, > > > > - KK > > > >> I think the semantics are that the pointer is only used if > >> private_data_len > 0. Otherwise, it is undefined. So I think we should > >> keep the check. Plus I don't like calling kfree() with a NULL pointer. > >> It just seems wrong... > >> > >> ;-) > >> > >> > >> On Thu, 2006-11-09 at 14:59 -0800, Roland Dreier wrote: > >>>>> if (iw_event->private_data_len) > >>>>> kfree(iw_event->private_data); > >>>> > >>>> Kfree checks for a null value, so is the private_data_len check > > necessary? > >>> > >>> Could private_data be a junk pointer if private_data_len == 0 ? > >>> > >>> - R. > >> > >> > >> _______________________________________________ > >> openib-general mailing list > >> openib-general@openib.org > >> http://openib.org/mailman/listinfo/openib-general > >> > >> To unsubscribe, please visit > > http://openib.org/mailman/listinfo/openib-general > >> > > > > > > _______________________________________________ > > openib-general mailing list > > openib-general@openib.org > > http://openib.org/mailman/listinfo/openib-general > > > > To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general > > > > _______________________________________________ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
