Re: [PATCH v3] sched_ext: Reject NMI calls to lock-taking kfuncs

[Tejun Heo]

Hello,

On Wed, Sep 02, 2026 at 05:36:11PM +0800, Wanwu Li wrote:
> +#define scx_kf_allowed_ctx(sch)						\
> +({										\
> +	bool __allowed = true;							\

Applied to sched_ext/for-7.4 with the following changes:

- "No need to wrap" in my v2 reply was about the line wrap of the function
  signature. Restored the inline function + macro wrapper form:

    static __always_inline bool __scx_kf_allowed_ctx(struct scx_sched *sch, const char *who)
    {
    	if (unlikely(in_nmi())) {
    		scx_error(sch, "%s called from NMI", who);
    		return false;
    	}
    	return true;
    }

    #define scx_kf_allowed_ctx(sch)	__scx_kf_allowed_ctx((sch), __func__)

- struct_ops don't run in task context (e.g. ops.tick() runs from the tick
  interrupt). They just never run in NMI. Updated the last paragraph of the
  description accordingly.

Thanks.

--
tejun