Re: [PATCH 2/4] x86/entry: Use asm_noist_exc_nmi() for NMI in early booting stage

[Steven Rostedt]

On Tue, 27 Apr 2021 07:09:47 +0800
Lai Jiangshan <jiangshanlai@xxxxxxxxx> wrote:

> While the other entries for the exceptions which use Interrupt stacks can
> be also used on the kernel stack, asm_exc_nmi() can not be used on the
> kernel stack for it relies on the RSP-located "NMI executing" variable
> which expects to on a fixed location in the NMI IST stack.  When it is
> unexpectedly called from the kernel stack, the RSP-located "NMI executing"
> variable is also on the kernel stack and is "uninitialized" and can cause
> the NMI entry to run in the wrong way.

Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

-- Steve