On 05/07, Roman Gushchin wrote: > > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -2484,9 +2484,6 @@ bool get_signal(struct ksignal *ksig) > sigdelset(¤t->pending.signal, SIGKILL); > recalc_sigpending(); > current->jobctl &= ~JOBCTL_TRAP_FREEZE; just noticed... perhaps it makes more sense to clear JOBCTL_TRAP_FREEZE before recalc_sigpending(). Or simply not clear it at all, see below. > - spin_unlock_irq(&sighand->siglock); > - if (unlikely(cgroup_task_frozen(current))) > - cgroup_leave_frozen(true); > goto fatal; > } > > @@ -2608,8 +2605,10 @@ bool get_signal(struct ksignal *ksig) > continue; > } > > - spin_unlock_irq(&sighand->siglock); > fatal: > + spin_unlock_irq(&sighand->siglock); > + if (unlikely(cgroup_task_frozen(current))) > + cgroup_leave_frozen(true); Yes, ptrace_signal() can return a fatal signal... and in this case we do not clear JOBCTL_TRAP_FREEZE. This doesn't look consistent with the code above. I can only repeat that somehow we need to cleanup/improve the whole logic. Say, a traced task reports syscall-enter. ptrace_stop() does enter_frozen(). The cgroup can become CGRP_FROZEN after that. Now the debugger does PTRACE_CONT, the frozen task actually starts the syscall. Obviously not good. Heh, and if this syscall is sys_exit or sys_exit_group we can hit the same warning. Oleg.