linux-kernel - Re: [PATCH v2 3/5] x86/boot/64: Show original faulting address in case of error

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Date:   Fri, 9 Oct 2020 16:42:15 +0200
From:   Joerg Roedel <jroedel@...e.de>
To:     Arvind Sankar <nivedita@...m.mit.edu>
Cc:     x86@...nel.org, Borislav Petkov <bp@...en8.de>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 3/5] x86/boot/64: Show original faulting address in
 case of error

On Thu, Oct 08, 2020 at 03:16:21PM -0400, Arvind Sankar wrote:
> This makes the #PF handler print the original CR2 value in case of
> error, instead of after aligning to PMD_SIZE.
> 
> Signed-off-by: Arvind Sankar <nivedita@...m.mit.edu>
> ---
>  arch/x86/boot/compressed/ident_map_64.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c
> index 063a60edcf99..fd957b2625e9 100644
> --- a/arch/x86/boot/compressed/ident_map_64.c
> +++ b/arch/x86/boot/compressed/ident_map_64.c
> @@ -327,9 +327,6 @@ void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code)
>  
>  	ghcb_fault = sev_es_check_ghcb_fault(address);
>  
> -	address   &= PMD_MASK;
> -	end        = address + PMD_SIZE;
> -
>  	/*
>  	 * Check for unexpected error codes. Unexpected are:
>  	 *	- Faults on present pages
> @@ -345,5 +342,8 @@ void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code)
>  	 * Error code is sane - now identity map the 2M region around
>  	 * the faulting address.
>  	 */
> +	address   &= PMD_MASK;
> +	end        = address + PMD_SIZE;
> +
>  	add_identity_map(address, end);
>  }

Reviewed-by: Joerg Roedel <jroedel@...e.de>