On 11/25, Eric W. Biederman wrote: > > Oleg Nesterov <o...@redhat.com> writes: > > > On 11/25, Eric W. Biederman wrote: > >> > >> My concern is exposing a half initialized struct pid to the world via an > >> rcu data structure. In particular could one of the rcu users get into > >> trouble because we haven't called get_pid_ns yet? That is unclear to me. > > > > They can't. This pid was fully initialized, in particular > > pid->numbers[pid->level].ns == ns has a reference. > > > > Just it is not ready for put_pid() which will be called by the "owner" of > > this pid, the caller or the new child. So in this sense it doesn't matter > > when we call get_pid_ns(), just we need to do this before return. > > Or by someone calling find_get_pid() ... put_pid(). > > Now the reference count should not hit zero in that case
Yes. this get_pid_ns() connects to atomic_set(&pid->count, 1) set by us. > but I hate to > think of that case separately. OK. > At this point, and especially since we need to Cc stable and get this > fix backported to who knows how many kernel releases having something > that is trivial to validate is correct is important. OK. I'll send V2 with -stable cc'ed. Oleg. -- 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/