linux-kernel - Re: [PATCH 2/5] kernel/dma: remove unnecessary unmap_kernel_range

Open Source and information security mailing list archives

Date:   Tue, 26 Jan 2021 17:08:46 -0500
From:   Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
To:     Nicholas Piggin <npiggin@...il.com>
Cc:     linux-mm@...ck.org, Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel@...r.kernel.org, iommu@...ts.linux-foundation.org,
        Robin Murphy <robin.murphy@....com>,
        Christoph Hellwig <hch@....de>
Subject: Re: [PATCH 2/5] kernel/dma: remove unnecessary unmap_kernel_range

On Tue, Jan 26, 2021 at 02:54:01PM +1000, Nicholas Piggin wrote:
> vunmap will remove ptes.

Should there be some ASSERT after the vunmap to make sure that is the
case? 
> 
> Cc: Christoph Hellwig <hch@....de>
> Cc: Marek Szyprowski <m.szyprowski@...sung.com>
> Cc: Robin Murphy <robin.murphy@....com>
> Cc: iommu@...ts.linux-foundation.org
> Signed-off-by: Nicholas Piggin <npiggin@...il.com>
> ---
>  kernel/dma/remap.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
> index 905c3fa005f1..b4526668072e 100644
> --- a/kernel/dma/remap.c
> +++ b/kernel/dma/remap.c
> @@ -66,6 +66,5 @@ void dma_common_free_remap(void *cpu_addr, size_t size)
>  		return;
>  	}
>  
> -	unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
>  	vunmap(cpu_addr);
>  }
> -- 
> 2.23.0
> 
> _______________________________________________
> iommu mailing list
> iommu@...ts.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/iommu

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