Oleg Nesterov [oleg@xxxxxxxxxx] wrote: | On 10/05, Sukadev Bhattiprolu wrote: | > | > Oleg Nesterov [oleg@xxxxxxxxxx] wrote: | > | | > | --- TTT_32/kernel/signal.c~FU_2_SEND_SIGNAL 2009-10-04 02:21:55.000000000 +0200 | > | +++ TTT_32/kernel/signal.c 2009-10-04 03:09:44.000000000 +0200 | > | @@ -928,9 +928,8 @@ static int send_signal(int sig, struct s | > | int from_ancestor_ns = 0; | > | | > | #ifdef CONFIG_PID_NS | > | - if (!is_si_special(info) && SI_FROMUSER(info) && | > | - task_pid_nr_ns(current, task_active_pid_ns(t)) <= 0) | > | - from_ancestor_ns = 1; | > | + from_ancestor_ns = si_fromuser(info) && | > | + !task_pid_nr_ns(current, task_active_pid_ns(t)); | > | > Makes sense. And we had mentioned earlier that container-init is immune | > to suicide but should we add a check for 'current == t' above to cover the | > | > send_sig(SIGKILL, current, 0); | > | > in load_aout_binary() and friends | > | > from_ancestor_ns = si_fromuser(info) && (current == t || | > !task_pid_nr_ns(current, task_active_pid_ns(t))); | | I don't think so. | | First of all, this is just ugly. If we need this check we should change | the callers, not send_signal(). Well, all I am saying is that the check !task_pid_nr_ns(current, task_active_pid_ns(t))) excludes container-init sending signal to itself - task_pid_nr_ns() above would return 1 for container-init and 'from_ancestor_ns' would be 0. But sure, we could use force_sig_info() in caller. | | But more importantly, I disagree with "container-init is immune to suicide" | above. This is another issue I was going to discuss later, lets do this now. Ok :-) | | When load_elf_binary() does send_sig(SIGKILL, current) init must die, because | we have no option. Exec failed, but we can't return to user-space with the | error code, it is too late. | Hence the SIGKILL - I agree with this. | So, imho this patch also fixes this case by accident, This part I am not sure. But as mentioned above, from_ancestor_ns is 0 and the SIGKILL will not queued right ? | but I think it would | be better to change load_aout_binary/etc to use force_sig_info() to make | the code more explicit. | | What do you think? | | Oleg. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
