Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx> writes: > Eric W. Biederman [ebiederm@xxxxxxxxxxxx] wrote: > > | > | - container-init is responsible for setting the rest of the signals > | to SIG_IGN. > > Oleg pointed out that we could drop SIG_DFL signals to global init early > to ensure wait_for_completion_killable/lock_page_killable don't incorrectly > believe that a fatal signal is pending. (patch 2/6). > > If that patch is valid regardless of containers, it would be a minor > extension to get container-inits to drop SIG_DFL signals too, right ? Yes. > So the bigger problem/unknown for me is the sig_from_user() in patch 4/6 > (i.e determining if it safe to deref the pid-ns of sender). We went from > !in_interrupt() to the SIG_FROM_USER flag to this. > > If that is correct, I am hoping it would come down to opitmizing the code > if possible (eg: can/should we avoid passing same_ns into sig_ignored() > > There is probably some ugliness :-) but do you see any other correctness > issues ? I haven't dug in too deep but right now my concern are user space semantics, I don't want to wind up with something ugly there because we can not change it later. So if we can write a description of what happens to signals to cinit that is right 100% of the time. Something we can write a test case for that tests all of the corner cases and it always get the same results. I am happy. I don't mind dropping signals early as an optimization, but if it is just an optimization we can't count on it in cinit. So I would rather deliver less and make user space deal with it, then deliver more cause problems for user space. Eric _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
