Hi Cristoph, On Tue, 2021-11-02 at 07:41 +0100, Christoph Hellwig wrote: > As others pointed out, DMA_ATTR_NO_KERNEL_MAPPING just means the > caller can't rely on a kernel mapping. So the "fix" here is > wrong. That being said for cases where we can easily remove a page > from the kernel mapping it would be nice to do to: > > a) improve security > b) as a debug check to see that no one actually tries to access it >
I will modify my commit message. Thanks for your comment. > > + /* remove kernel mapping for pages */ > > + set_memory_valid((unsigned > > long)phys_to_virt(dma_to_phys(dev, *dma_handle)), > > Please avoid overly long lines. Also this function only exists for > arm64 > also and others pointed out won't work for all cases. Got it. I will send v2 patch. Thanks for your review and suggestion. Walter _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
