Re: [PATCH v8 0/2] dma-buf: Fix silent overflow and alignment

[Christian König]

On 9/2/26 09:39, Leon Romanovsky wrote:
> On Wed, Sep 02, 2026 at 09:00:46AM +0200, Christian König wrote:
>> On 9/1/26 19:08, David Hu wrote:
>>> From: David Hu <xuehaohu@xxxxxxxxxx>
>>>
>>> This series address two related issues in scatter-gather mapping,
>>> specifically for the MMIO based dma-buf mapping. The fixes ensure
>>> sgt mapping is correct, and proper for large MMIO regions.
>>>
>>> Patch 1 fixes a silent integer overflow for mapping length exceeding 4G
>>> (Previously submitted as [PATCH v7] dma-buf: Fix silent overflow for
>>> phys vec to sgt)
>>> https://lore.kernel.org/all/20260609164047.486227-1-xuehaohu@xxxxxxxxxx/
>>>
>>> Patch 2 Splits sgl by largest page aligned chunk
>>> (Previously submitted as [PATCH v3] dma-buf: Split sgl by largest page-aligned chunk)
>>> https://lore.kernel.org/all/20260722233806.3922093-1-dhu@xxxxxx/
>>
>> *sigh* such issues are exactly the reason why I didn't wanted the dma-mapping stuff inside DMA-buf. That clearly doesn't belong here.
> 
> And this is why so many in the kernel community want to get rid of SG
> lists. It would be great if DMA-BUF could also eliminate the need to
> convert to an SGL, like Jason proposed.
> 
> The DMA layer no longer needs SGL. These bugs belong to the DMA-BUF layer,
> which is the one that depends on it.

I'm all fine using an array/xarray of dma_addr_t in DMA-buf, just phys_vec is a clear no-go.

Regards,
Christian.

> 
> Thanks