> - /* Sanity check this really should not happen. */ > - if (hmm == NULL || range->end <= range->start) > - return; > - > mutex_lock(&hmm->lock); > list_del_rcu(&range->list); > mutex_unlock(&hmm->lock); > > /* Drop reference taken by hmm_range_register() */ > - range->valid = false; > mmput(hmm->mm); > hmm_put(hmm); > - range->hmm = NULL; > + > + /* > + * The range is now invalid and the ref on the hmm is dropped, so > + * poison the pointer. Leave other fields in place, for the caller's > + * use. > + */ > + range->valid = false; > + memset(&range->hmm, POISON_INUSE, sizeof(range->hmm)); Formatting seems to be messed up. But again I don't see the value in the poisoning, just let normal linked list debugging do its work. The other cleanups looks fine to me.
