linux-kernel - Re: [PATCH 2/3] x86/mm: Sync also unmappings in vmalloc_sync

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Message-ID: <28a4c10f-f895-e8ff-d07b-9e4c35aa6342@intel.com>
Date:   Wed, 17 Jul 2019 14:06:01 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     Joerg Roedel <joro@...tes.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Joerg Roedel <jroedel@...e.de>
Subject: Re: [PATCH 2/3] x86/mm: Sync also unmappings in vmalloc_sync_one()

On 7/17/19 12:14 AM, Joerg Roedel wrote:
> 
> diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
> index 4a4049f6d458..d71e167662c3 100644
> --- a/arch/x86/mm/fault.c
> +++ b/arch/x86/mm/fault.c
> @@ -194,11 +194,12 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
>  
>  	pmd = pmd_offset(pud, address);
>  	pmd_k = pmd_offset(pud_k, address);
> -	if (!pmd_present(*pmd_k))
> -		return NULL;
>  
> -	if (!pmd_present(*pmd))
> +	if (pmd_present(*pmd) ^ pmd_present(*pmd_k))
>  		set_pmd(pmd, *pmd_k);

Wouldn't:

	if (pmd_present(*pmd) != pmd_present(*pmd_k))
		set_pmd(pmd, *pmd_k);

be a bit more intuitive?

But, either way, these look fine.  For the series:

Reviewed-by: Dave Hansen <dave.hansen@...ux.intel.com>