If your supervisor is talking about others under his supervision, he quite probably is violating at least company policy, and depending on where your company is located the supervisor may be violating various laws respecting confidentiality of employee performance evaluations.

If your company is large enough to have a "Personnel" or "Human Resources" manager, it would be appropriate to request advice from that office regarding the behavio(u)r of the supervisor. In a large enough company, there quite likely is an "Ethics Advisor" who could be a resource. Your entry to an Ethics officer could be that you may be at risk by hearing/knowing your supervisors "evaluations" of other employees and need to know how you should handle the information.

If your supervisor has changed his/her time of coming in to "visit" with you before normal working time, or has changed "what he/she does" before work, there is the possibility that he/she "enjoys your company" a bit too much and just doesn't have anything else to talk about. This could be construed, in the US at least, as "sexual harrassment" (even if you're both of the same sex) but certainly qualifies as "creating a hostile work environment" which is the core "complaint" of most regulated activity of this sort.

Be very aware that the "social structure of management" at your company has a very strong bearing on whether you can survive making a complaint to those responsible for handling a situation of this kind. YOU are not the one who should have to deal with it, but in many companies/organizations the one in authority will have no difficulty making it look like any complaint is "all your fault." Many companies are so sensitive to legal actions resulting from any complaint that they "circle the wagons" to protect the manager(s) at the first overt hint of any complaint; and if this is the case the employee always loses.

It may also depend a lot on how competent the individuals in the responsible positions (HR, Personnel, Ethics) are, and my own experience is that most likely "not very" is the common level of competence.

If you choose to seek help through "official channels" you will be asked if you have directly informed the supervisor of the problem; and your complaint likely will be ignored if you have not done so.

If you prefer not to "go official," which realistically may be your only choice, removing yourself as the target of the supervisor's whining is perhaps your best option.

If possible, you might try to vary your morning routine by taking your "attitude time" elsewhere, such as in the company cafeteria if there is one, or at a nearby coffee shop. Unpredictably varying when you arrive at your workplace might make you less "available" for the supervisor's gripe sessions, and might help break the habit of coming to you.

Finding an "errand" to run whenever the gossip starts, even if it's just "an emergency potty break" might be sufficient to give the message that you do not wish to participate in the gossip.

Repeatedly interjecting "How does that affect my job?" and/or "What do you expect me to do about it?" and demanding an answer would be a more aggressive (and risky) approach. ("I want to know why you think I should know this.")

You probably cannot change your supervisor's habits, but you may be able to remove yourself as the target.

If you successfully "unlatch" yourself, you can of course be assured that this supervisor will find a new victim, to whom all your faults will be revealed ...

And of course, this may be an "opportunity" for you to investigate a position with "better opportunities for advancement" - within your present company or elsewhere.

John