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    SubjectRe: [PATCH 20/40] mn10300: Use set_current_blocked() and block_sigmask()
    On 02/14, David Howells wrote:
    > Oleg Nesterov <> wrote:
    > > No, only current can change ->blocked. This is even documented in
    > > sigprocmask(). And more, the only correct way to change ->blocked
    > > is set_current_blocked(). OK, with a couple of "I know what I am
    > > doing" exceptions in kernel/signal.c.
    > I was looking at force_sig_info() and derivatives. Is that what you refer to?

    Ah, sorry, forgot to mention...

    force_sig_info() (and its callers) need the cleanups and fixes. It
    is almost always wrong if t != current.

    For example, please look at

    [PATCH 1/4] signal: give SEND_SIG_FORCED more power to beat SIGNAL_UNKILLABLE

    Hopefully we can fix all ab-users soon.

    Just in case... if we race with force_sig_info() the task will be
    killed anyway. But I agree, this is not nice and should be fixed.
    And in any case, there are other places which assume it is safe
    to read current->blocked lockless.

    > If so, is it worth providing a force_sig_info_current(),
    > force_sigsegv_current() and force_sig_current() to make things clearer to grep
    > for, I wonder?

    Yes, I think the "task_struct *t" argument should die.


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