Messages in this thread | | | From | (Eric W. Biederman) | Date | Tue, 09 Dec 2014 13:31:39 -0600 | Subject | Re: [CFT][PATCH 6/7] userns: Add a knob to disable setgroups on a per user namespace basis |
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ebiederm@xmission.com (Eric W. Biederman) writes:
> Andy Lutomirski <luto@amacapital.net> writes: > >> >> This text was actually my suggested comment text. > > Now I see. > >> If you put smp_rmb() in this function with a comment like that, then I >> think it will all make sense and be obviously correct (even with most >> of the other barriers removed). > > Right. > > Given that we have to be careful when using these things anyway what > I was hoping to achieve with the barriers appears impossible, and > confusing so I will see about just adding barriers where we need them > for real. Sigh.
Doh. The code has been entirely too clever.
There are no need for atomics or other cleverness, I just need to generalize id_map_mutex. I knew that had to be a trivially correct way of handling this mess.
Eric
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