Re: [PATCH] x86: add hintable NOPs emulation

[Ahmed S. Darwish]

On Wed, 20 Aug 2025, Ahmed S. Darwish wrote:
>
> Please do:
>
>     #ifdef CONFIG_X86_HNOP_EMU
>     static bool handle_hnop(struct pt_regs *regs)
>     {
> 	// Reference 'hnop_warn' as much as you like
>     }
>     #else
>     static bool handle_hnop(struct pt_regs *regs)
>     {
> 	return false;
>     }
>     # endif
>

And as previously suggested: remove the ugly hnop_warn stuff from
'thread_struct', then you can even just do:

    static bool handle_hnop(struct pt_regs *regs)
    {
	if (!IS_ENABLED(CONFIG_X86_HNOP_EMU))
		return false;

	pr_warn_once("%s[%d] Emulating hintable NOP\n"
		     "This warning will not be repeated; even for other binaries\n"
		     current->comm, task_pid_nr(current));

	...
    }

And everything else will fit quietly in place.

--
Ahmed S. Darwish
Linutronix GmbH