On 08/20, Eric W. Biederman wrote: > > Oleg Nesterov <[email protected]> writes: > > > On 08/19, Andy Lutomirski wrote: > >> > >> On Mon, Aug 19, 2013 at 11:33 AM, Oleg Nesterov <[email protected]> wrote: > >> > > >> > So do you think this change is fine or not (ignoring the fact it needs > >> > cleanups) ? > >> > >> I think that removing the CLONE_VM check is fine (although there are > >> some other ones that should probably be removed as well), but I'm not > >> sure if that check needs replacing with something else. > > > > OK, thanks... but I still can't understand. > > > > The patch I sent is equivalent to the new one below. I just tried to > > unify it with another check in do_fork(). > > The patch below also needs CLONE_SIGHAND. You can't meaningfully share > signal handlers if you can't represent the pid in the siginfo. pids and > signals are too interconnected.
I don't really understand. If we allow to share ->mm (with this patch), why it is bad to share sighand_struct->action[] ? This only shares the pointers to the code which handles a signal. However I agree it probably makes sense to deny it "just in case", I do not think CLONE_SIGHAND can be useful in this case. But then we should also deny CLONE_SIGHAND if CLONE_NEWUSER|CLONE_NEWPID (another check in do_fork()). Which makes me think again we should unify these 2 checks. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
