On Mon, Mar 18, 2024 at 02:27:44PM +0300, Dmitry Mastykin wrote: > Hello all, > It seems there is a problem in "Krefs and RCU" example, that may cause > a crash. > I marked the place between two problem lines with "problem is here" comment. > If list_del_rcu() will be called between these lines, and list will become > empty, then q.next will not point to a valid struct my_data. > entry->refcount will also be invalid. > Instead, q.next must be read first, and then compared with q to check > list's emptiness (for example like in list_for_each_entry_rcu macro). I agree you've identified a problem, but there's no way we should apply this patch that adds "problem is here"! Instead we should show the proper usage, which is a call to list_first_or_null_rcu().
