Re: [PATCH] net: vmxnet3: avoid accessing the data mapped to streaming DMA

On 2020/8/4 6:59, David Miller wrote:

From: Jia-Ju Bai <redacted>
Date: Sun,  2 Aug 2020 21:11:07 +0800

quoted

In vmxnet3_probe_device(), "adapter" is mapped to streaming DMA:
   adapter->adapter_pa = dma_map_single(..., adapter, ...);

Then "adapter" is accessed at many places in this function.

Theses accesses may cause data inconsistency between CPU cache and
hardware.

To fix this problem, dma_map_single() is called after these accesses.

Signed-off-by: Jia-Ju Bai <redacted>

'adapter' is accessed everywhere, in the entire driver, not just here
in the probe function.

Okay, replacing dma_map_single() with dma_alloc_coherent() may be better.
If you think this solution is okay, I can submit a new patch.


Best wishes,
Jia-Ju Bai