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    Subjectself_exec_id/parent_exec_id && CLONE_PARENT
    (change subject)

    On 03/11, Oleg Nesterov wrote:
    > Well, I don't think it is right to add this counter into task_struct.
    > It should be per-process, signal_struct makes more sense. Or may be
    > mm_struct.
    > Btw this is also true for parent_exec_id/self_exec_id, but this is
    > another story.

    In fact I think it would be nice to kill parent_exec_id/self_exec_id.

    Afaics, this only problem is clone(CLONE_PARENT | SIGXXX). I expect
    the answer is "no, can break existing applications", but I'll ask

    Can't we change this? IOW, can't we modify copy_process

    - p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
    + p->exit_signal =
    + (clone_flags & CLONE_THREAD) ? -1 :
    + (clobe_flags & CLONE_PARENT) ? current->group_leader->exit_signal :
    + (clone_flags & CSIGNAL);

    (or simply use SIGCHLD instead of group_leader->exit_signal).

    Then we can kill parent_exec_id/self_exec_id if me modify de_thread()
    to set ->exit_signal = SIGCHLD for every child.

    I am also asking because the change above looks like the fix to me.
    The child must not control its ->exit_signal, it is the parent who
    decides which signal the child should use for notification.

    And to me, clone(CLONE_PARENT | SIGXXX) looks like a violation of
    rule above.


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