Re: [PATCH 07/19] x86/dumpstack: add IRQ_USABLE_STACK_SIZE define

[Andy Lutomirski]

On Thu, Jul 21, 2016 at 2:21 PM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> For reasons unknown, the x86_64 irq stack starts at an offset 64 bytes
> from the end of the page.  At least make that explicit.

This is a change in behavior -- see below.  Please mention this in the
changelog.

>
> FIXME: Can we just remove the 64 byte gap?  If not, at least document
> why.

I have no clue.

>
>         irq_stack_end   = (unsigned long *)(per_cpu(irq_stack_ptr, cpu));
> -       irq_stack       = (unsigned long *)(per_cpu(irq_stack_ptr, cpu) - IRQ_STACK_SIZE);
> +       irq_stack       = (unsigned long *)(per_cpu(irq_stack_ptr, cpu) -
> +                         IRQ_USABLE_STACK_SIZE);

This is different.