On Thu, Jun 11, 2020 at 12:20:32PM -0700, David Rientjes wrote:
> When a coherent mapping is created in dma_direct_alloc_pages(), it needs
> to be decrypted if the device requires unencrypted DMA before returning.
>
> Fixes: 3acac065508f ("dma-mapping: merge the generic remapping helpers
> into dma-direct")
> Cc: sta...@vger.kernel.org # 5.5+
> Signed-off-by: David Rientjes <rient...@google.com>
> ---
> kernel/dma/direct.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
> --- a/kernel/dma/direct.c
> +++ b/kernel/dma/direct.c
> @@ -195,6 +195,12 @@ void *dma_direct_alloc_pages(struct device *dev, size_t
> size,
> __builtin_return_address(0));
> if (!ret)
> goto out_free_pages;
> + if (force_dma_unencrypted(dev)) {
> + err = set_memory_decrypted((unsigned long)ret,
> + 1 << get_order(size));
> + if (err)
> + goto out_free_pages;
> + }
Note that ret is a vmalloc address here. Does set_memory_decrypted
work for that case? Again this should be mostly theoretical, so I'm
not too worried for now.
