On Fri, 30 Nov 2007, Greg KH wrote: > > However if kobject_add() is never called, or if it is called and it > > fails, then it's okay to use kfree(). It's not clear whether this > > distinction will matter in practice. It's probably best to document > > this using your stronger description. > > No, if kobject_add() fails, kobject_put() still must be called in order > to free up the name pointer, unless you are somehow guessing that the > "kobject_set_name()" portion of kobject_add() somehow failed.
Actually I imagined that if kobject_add() failed it would back out all the changes it made -- which means it would deallocate the name string. But requiring people to call kobject_put() will do this just as well. > And you > can't know that, so you have to call kobject_put() in order to be safe > and clean up everything. > > Now why did we not do the final kobject_put() in kobject_del() as well? > Doing two calls, always in order, seems a bit strange, anyone know why > it's this way? To be symmetrical with kobject_init() and kobject_add(). Besides, isn't there kobject_unregister()? Presumably it will go away along with kobject_register(), though. > > You could put that a little less strongly. After kobject_init() you > > SHOULD call kobject_put() to clean up properly, and after kobject_add() > > you MUST call kobject_del() and kobject_put(). > > No, in looking at the code, you only need to call kobject_del() to clean > everything up properly, if kobject_add() succeeds. No need to call > kobject_put() yet again. Sorry, yes, that's what I meant. After a successful call to kobject_add() you must call kobject_del() to undo the _add, and then kobject_put() for the final cleanup. Alan Stern - 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/
