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* Is it needed to zero out the dma buffer for DMA_ATTR_NO_KERNEL_MAPPING
@ 2020-09-04  2:28 ` Hillf Danton
  2020-09-04  9:10     ` Marek Szyprowski
  0 siblings, 1 reply; 3+ messages in thread
From: Hillf Danton @ 2020-09-04  2:28 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: Hillf Danton, Kees Cook, linux-kernel, linux-nvme,
	James Bottomley, Matthew Wilcox, Marek Szyprowski


Hi Folks

Currently the DMA_ATTR_NO_KERNEL_MAPPING buffer allocated is not
cleared while dma core always zero it out for coherent allocations.

Is it making sense to do memset for the attr?

Thanks
Hillf


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Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Is it needed to zero out the dma buffer for DMA_ATTR_NO_KERNEL_MAPPING
  2020-09-04  2:28 ` Is it needed to zero out the dma buffer for DMA_ATTR_NO_KERNEL_MAPPING Hillf Danton
@ 2020-09-04  9:10     ` Marek Szyprowski
  0 siblings, 0 replies; 3+ messages in thread
From: Marek Szyprowski @ 2020-09-04  9:10 UTC (permalink / raw)
  To: Hillf Danton, Christoph Hellwig
  Cc: Kees Cook, linux-nvme, linux-kernel, James Bottomley, Matthew Wilcox

Hi

On 04.09.2020 04:28, Hillf Danton wrote:
> Currently the DMA_ATTR_NO_KERNEL_MAPPING buffer allocated is not
> cleared while dma core always zero it out for coherent allocations.
>
> Is it making sense to do memset for the attr?

If it is not cleared then this is a bug. Please propose a patch fixing 
this issue.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Is it needed to zero out the dma buffer for DMA_ATTR_NO_KERNEL_MAPPING
@ 2020-09-04  9:10     ` Marek Szyprowski
  0 siblings, 0 replies; 3+ messages in thread
From: Marek Szyprowski @ 2020-09-04  9:10 UTC (permalink / raw)
  To: Hillf Danton, Christoph Hellwig
  Cc: James Bottomley, Matthew Wilcox, Kees Cook, linux-nvme, linux-kernel

Hi

On 04.09.2020 04:28, Hillf Danton wrote:
> Currently the DMA_ATTR_NO_KERNEL_MAPPING buffer allocated is not
> cleared while dma core always zero it out for coherent allocations.
>
> Is it making sense to do memset for the attr?

If it is not cleared then this is a bug. Please propose a patch fixing 
this issue.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland


_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-09-04  9:11 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-09-04  2:28 ` Is it needed to zero out the dma buffer for DMA_ATTR_NO_KERNEL_MAPPING Hillf Danton
2020-09-04  9:10   ` Marek Szyprowski
2020-09-04  9:10     ` Marek Szyprowski

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