Re: [PATCH v14 10/12] x86/smpboot: Send INIT/SIPI/SIPI to secondary CPUs in parallel

[Thomas Gleixner]

On Sat, Mar 11 2023 at 09:55, David Woodhouse wrote:
> On Sat, 2023-03-11 at 10:54 +0200, Thomas Gleixner wrote:
> I think I'll do it with a 'bool unpoison' argument to
> idle_thread_get(). Or just make it unconditional; they're idempotent
> anyway and cheap enough? Kind of weird to be doing it from finish_cpu()
> though, so I'll probably stick with the argument.

Eew.

> ....*types*....
>
> Erm, there are circumstances (!CONFIG_GENERIC_SMP_IDLE_THREAD) when
> idle_thread_get() just unconditionally returns NULL.
>
> At first glance, it doesn't look like scs_task_reset() copes with being
> passed a NULL. Am I missing something?

Shadow call stacks are only enabled by arm64 today, and that uses
the generic idle threads.

Thanks,

        tglx