Re: [PATCH] x86/process: fix the misleading comment about PF_USER_WORKERs in copy_thread()

[Dave Hansen <dave.hansen@intel.com>]

On 8/20/25 09:46, Oleg Nesterov wrote:
>  	if (unlikely(args->fn)) {
>  		/*
> -		 * A user space thread, but it doesn't return to
> -		 * ret_after_fork().
> +		 * A non-PF_KTHREAD thread, but it doesn't return from
> +		 * ret_from_fork().
> +		 *
> +		 * Either a PF_USER_WORKER kernel thread, in this case
> +		 * arg->fn() must not return.
> +		 * Or a user space task created by user_mode_thread(), in
> +		 * this case arg->fn() can only return after a successful
> +		 * kernel_execve().
>  		 *
>  		 * In order to indicate that to tools like gdb,
>  		 * we reset the stack and instruction pointers.
>  		 *
>  		 * It does the same kernel frame setup to return to a kernel
> -		 * function that a kernel thread does.
> +		 * function that a PF_KTHREAD thread does.
>  		 */

I'm not sure that comment clarifies things, especially the new
paragraph. This does _not_ seem like the place to me to be explaining
what the conventions are around arg->fn(). It would be better to put it
near the definition or 'kernel_clone_args' or the place the function
gets called, but not here.