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From:   Thomas Gleixner <tglx@linutronix.de>
To:     Andy Lutomirski <luto@kernel.org>,
        Andy Lutomirski <luto@kernel.org>
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Subject: Re: [patch V6 07/37] x86/entry: Provide helpers for execute on irqstack
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Andy Lutomirski <luto@kernel.org> writes:
> Actually, I revoke my ack.  Can you make one of two changes:
>
> Option A: Add an assertion to run_on_irqstack to verify that irq_count
> was -1 at the beginning?  I suppose this also means you could just
> explicitly write 0 instead of adding and subtracting.
>
> Option B: Make run_on_irqstack() just call the function on the current
> stack if we're already on the irq stack.
>
> Right now, it's too easy to mess up and not verify the right
> precondition before calling run_on_irqstack().
>
> If you choose A, perhaps add a helper to do the if(irq_needs_irqstack)
> dance so that users can just do:
>
> run_on_irqstack_if_needed(...);
>
> instead of checking everything themselves.

I'll have a look tomorrow morning with brain awake.