Hi Oleg, On Thu, Apr 27, 2017 at 01:16:51PM +0100, Jamie Iles wrote: > On Wed, Apr 26, 2017 at 05:18:58PM +0200, Oleg Nesterov wrote: > > Hi Jamie, > > > > On 04/25, Jamie Iles wrote: > > > > > > Hi Oleg, > > > > > > I'm back looking at SIGNAL_UNKILLABLE and debugging child reapers again, > > > and the current issue is when running code in the target process, > > > SIGTRAP firing and that causing SIGNAL_UNKILLABLE protection to be > > > removed in force_sig_info(): > > > > > > if (action->sa.sa_handler == SIG_DFL) > > > t->signal->flags &= ~SIGNAL_UNKILLABLE; > > > > Yes, this is what I meant when I said force_sig_info() needs changes too. > > I was going to fix it "tomorrow" but I was distracted and then forgot. > > > > > @@ -1185,7 +1185,7 @@ force_sig_info(int sig, struct siginfo *info, > > > struct task_struct *t) > > > recalc_sigpending_and_wake(t); > > > } > > > } > > > - if (action->sa.sa_handler == SIG_DFL) > > > + if (action->sa.sa_handler == SIG_DFL && !t->ptrace) > > > t->signal->flags &= ~SIGNAL_UNKILLABLE; > > > ret = specific_send_sig_info(sig, info, t); > > > spin_unlock_irqrestore(&t->sighand->siglock, flags); > > > > Not sure, let me think a bit more... and this is not enough anyway. > > > > perhaps we should start with this simple change, but the "real" fix > > needs a lot of cleanups, although I am not sure if we will ever do this. > > Okay, sounds good. I'm happy to spend more time looking at this if you > have suggestions - in the context of namespaces and containers this > seems more relevant than when it was just the system init that we were > protecting.
Any objections to moving ahead with this patch? Thanks, Jamie
