linux-kernel - [PATCH 5.7 122/265] dma-direct: re-encrypt memory if dma_direct_alloc

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Date:   Mon, 29 Jun 2020 11:15:55 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     David Rientjes <rientjes@...gle.com>,
        Christoph Hellwig <hch@....de>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.7 122/265] dma-direct: re-encrypt memory if dma_direct_alloc_pages() fails

From: David Rientjes <rientjes@...gle.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@...gle.com>
Signed-off-by: Christoph Hellwig <hch@....de>
Signed-off-by: Sasha Levin <sashal@...nel.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