On Mon, Apr 16, 2007 at 03:03:16PM -0400, Dmitry Torokhov wrote: > On 4/16/07, Greg KH <[EMAIL PROTECTED]> wrote: > >On Mon, Apr 16, 2007 at 02:30:17PM -0400, Dmitry Torokhov wrote: > >> On 4/16/07, Cornelia Huck <[EMAIL PROTECTED]> wrote: > >> >Hi, > >> > > >> >based on the discussion in "How should an exit routine wait for > >> >release() callbacks?", I've cooked up some patches that make module > >> >unload wait until the last reference for a kobject has been dropped. > >> >This should plug the "release function in already deleted module" race; > >> >however, if the last kobject_put() from the module containing the > >> >release function is not in the module's exit function, there's still a > >> >small window (not sure if and how to plug this). > >> > >> Unfortunately all this "wait for refcount in module's exit" schemas > >> lead to the following deadlock: > >> > >> rmmod my_module < /path/to/some/file/incrementing/my/refcount > > > >No, it should just return "module in use" as the reference count it > >grabbed before rmmod is called. > > > > No, because it it were module's refcount we woudl not have problem > with ->release() to begin with. It is object's refcount.
Yes, but with these patches, we are incrementing that reference count when the kobject is created, which will cause this to fail. > >But either way, that's just foolish to try to prevent that from failing > >:) > > Why? It works now for most of teh subsystems. That's because it is buggy :) thanks, greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
