Re: [PATCH v1 16/16] dma-mapping: Disallow .map_sg operations from returning zero on error

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2021-07-16 07:33, Christoph Hellwig wrote:
On Thu, Jul 15, 2021 at 10:45:44AM -0600, Logan Gunthorpe wrote:
@@ -194,6 +194,8 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
  	else
  		ents = ops->map_sg(dev, sg, nents, dir, attrs);
+ WARN_ON_ONCE(ents == 0);

Turns this into a negative error code while we're at it, just to keep
the callers sane?

Right, by this point returning the 0 would pass through dma_map_sg_attrs() OK, but AFAICS dma_map_sgtable() would now get confused and return success but with sgt->nents = 0. Coercing it to an error code (which dma_map_sg_attrs() would then just change right back) seems sensible for the sake of easy robustness.

Robin.



[Index of Archives]     [LKML Archive]     [Linux ARM Kernel]     [Linux ARM]     [Git]     [Yosemite News]     [Linux SCSI]     [Linux Hams]

  Powered by Linux