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    SubjectRe: [GIT PULL] Please pull proc and exec work for 5.7-rc1
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    On 4/3/20 6:23 PM, Linus Torvalds wrote:
    > On Fri, Apr 3, 2020 at 8:09 AM Bernd Edlinger <bernd.edlinger@hotmail.de> wrote:
    >>
    >> On 4/2/20 9:04 PM, Linus Torvalds wrote:
    >>> In fact, then you could drop the
    >>>
    >>> mutex_unlock(&tsk->signal->exec_update_mutex);
    >>>
    >>> in the error case of exec_mmap(), because now the error handling in
    >>> free_bprm() would do the cleanup automatically.
    >>>
    >>
    >> The error handling is sometimes called when the exec_update_mutex is
    >> not taken, in fact even de_thread not called.
    >
    > But that's the whole point of the flag. Make the flag be about "do I
    > hold the mutex", and then the error handling does the right thing
    > regardless.
    >
    >> Can you say how you would suggest that to be done?
    >
    > I think the easiest thing to do to explain is to just write the patch.
    >
    > This is entirely untested, but see what the difference is? I make the
    > flag be about exactly where I take the lock, not about some "I have
    > called exec_mmap".
    >
    > Which means that now exec_mmap() doesn't even need to unlock it in the
    > error case, because the unlocking will happen properly in the
    > bprm_exit regardless.
    >
    > This makes that unconditional unlocking logic much more obvious.
    >
    > That said, Eric says he can make it all properly static so that it
    > doesn't need that kind of dynamic "if (x) unlock()" logic at all,
    > which is much better.
    >
    > So this patch is not for consumption, it's purely for "look, something
    > like this"
    >

    Works for me. But I also want to wait for Eric, I am curious.
    I have a lot of time.


    Bernd.

    > Linus
    >

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