[PATCH 5.7 122/265] dma-direct: re-encrypt memory if dma_direct_alloc_pages() fails

Sasha Levin
2020-06-29T21:50:13Z

From: David Rientjes <rientjes@google.com>

[ Upstream commit 96a539fa3bb71f443ae08e57b9f63d6e5bb2207c ]

If arch_dma_set_uncached() fails after memory has been decrypted, it needs
to be re-encrypted before freeing.

Fixes: fa7e2247c572 ("dma-direct: make uncached_kernel_address more general")
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/dma/direct.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 8f4bbdaf965eb..4e789c46ff0bf 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -186,7 +186,7 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
arch_dma_prep_coherent(page, size);
ret = arch_dma_set_uncached(ret, size);
if (IS_ERR(ret))
- goto out_free_pages;
+ goto out_encrypt_pages;
}
done:
if (force_dma_unencrypted(dev))
@@ -194,6 +194,11 @@ done:
else
*dma_handle = phys_to_dma(dev, page_to_phys(page));
return ret;
+
+out_encrypt_pages:
+ if (force_dma_unencrypted(dev))
+ set_memory_encrypted((unsigned long)page_address(page),
+ 1 << get_order(size));
out_free_pages:
dma_free_contiguous(dev, page, size);
return NULL;
--
2.25.1