Re: [PATCH v10 04/11] x86/entry/64: Adapt assembly for PIE support

[Peter Zijlstra]

On Wed, Dec 04, 2019 at 04:09:41PM -0800, Thomas Garnier wrote:

> @@ -1625,7 +1627,11 @@ first_nmi:
>  	addq	$8, (%rsp)	/* Fix up RSP */
>  	pushfq			/* RFLAGS */
>  	pushq	$__KERNEL_CS	/* CS */
> -	pushq	$1f		/* RIP */
> +	pushq	$0		/* Future return address */

We're building an IRET frame, the IRET frame does not have a 'future
return address' field.

> +	pushq	%rdx		/* Save RAX */

fail..

> +	leaq	1f(%rip), %rdx	/* RIP */

nonsensical comment

> +	movq    %rdx, 8(%rsp)   /* Put 1f on return address */
> +	popq	%rdx		/* Restore RAX */

fail..

>  	iretq			/* continues at repeat_nmi below */
>  	UNWIND_HINT_IRET_REGS
>  1:
> -- 
> 2.24.0.393.g34dc348eaf-goog
>