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From:   Ard Biesheuvel <ardb@kernel.org>
To:     linux-crypto@vger.kernel.org
Cc:     herbert@gondor.apana.org.au, keescook@chromium.org,
        Ard Biesheuvel <ardb@kernel.org>
Subject: [PATCH 2/8] crypto: safexcel - take request size after setting TFM
Date:   Wed,  6 Apr 2022 16:27:09 +0200
Message-Id: <20220406142715.2270256-3-ardb@kernel.org>
In-Reply-To: <20220406142715.2270256-1-ardb@kernel.org>
References: <20220406142715.2270256-1-ardb@kernel.org>
MIME-Version: 1.0
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The skcipher, aead and ahash request structure types will no longer be
aligned for DMA, and the padding and re-alignment of the context buffer
region will be taken care of at runtime.

This means that we need to update the stack representation accordingly,
to ensure that the context pointer doesn't point past the allocation
after rounding.

Also, as getting at the context pointer of a skcipher_request will
involve a check of the underlying algo's cra_flags field, as it may need
to be aligned for DMA, defer grabbing the context pointer until after
setting the TFM.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/crypto/inside-secure/safexcel.h        | 15 +++++++++------
 drivers/crypto/inside-secure/safexcel_cipher.c |  8 ++++----
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/crypto/inside-secure/safexcel.h b/drivers/crypto/inside-secure/safexcel.h
index ce1e611a163e..b5033803714a 100644
--- a/drivers/crypto/inside-secure/safexcel.h
+++ b/drivers/crypto/inside-secure/safexcel.h
@@ -56,12 +56,15 @@
 				 GFP_KERNEL : GFP_ATOMIC)
 
 /* Custom on-stack requests (for invalidation) */
-#define EIP197_SKCIPHER_REQ_SIZE	sizeof(struct skcipher_request) + \
-					sizeof(struct safexcel_cipher_req)
-#define EIP197_AHASH_REQ_SIZE		sizeof(struct ahash_request) + \
-					sizeof(struct safexcel_ahash_req)
-#define EIP197_AEAD_REQ_SIZE		sizeof(struct aead_request) + \
-					sizeof(struct safexcel_cipher_req)
+#define EIP197_SKCIPHER_REQ_SIZE	(ALIGN(sizeof(struct skcipher_request),	\
+					       CRYPTO_MINALIGN) +		\
+					 sizeof(struct safexcel_cipher_req))
+#define EIP197_AHASH_REQ_SIZE		(ALIGN(sizeof(struct ahash_request),	\
+					       CRYPTO_MINALIGN) +		\
+					 sizeof(struct safexcel_ahash_req))
+#define EIP197_AEAD_REQ_SIZE		(ALIGN(sizeof(struct aead_request),	\
+					       CRYPTO_MINALIGN) +		\
+					 sizeof(struct safexcel_cipher_req))
 #define EIP197_REQUEST_ON_STACK(name, type, size) \
 	char __##name##_desc[size] CRYPTO_MINALIGN_ATTR; \
 	struct type##_request *name = (void *)__##name##_desc
diff --git a/drivers/crypto/inside-secure/safexcel_cipher.c b/drivers/crypto/inside-secure/safexcel_cipher.c
index d68ef16650d4..6dc3e171f474 100644
--- a/drivers/crypto/inside-secure/safexcel_cipher.c
+++ b/drivers/crypto/inside-secure/safexcel_cipher.c
@@ -1108,7 +1108,6 @@ static int safexcel_cipher_exit_inv(struct crypto_tfm *tfm,
 static int safexcel_skcipher_exit_inv(struct crypto_tfm *tfm)
 {
 	EIP197_REQUEST_ON_STACK(req, skcipher, EIP197_SKCIPHER_REQ_SIZE);
-	struct safexcel_cipher_req *sreq = skcipher_request_ctx(req);
 	struct safexcel_inv_result result = {};
 
 	memset(req, 0, sizeof(struct skcipher_request));
@@ -1117,13 +1116,13 @@ static int safexcel_skcipher_exit_inv(struct crypto_tfm *tfm)
 				      safexcel_inv_complete, &result);
 	skcipher_request_set_tfm(req, __crypto_skcipher_cast(tfm));
 
-	return safexcel_cipher_exit_inv(tfm, &req->base, sreq, &result);
+	return safexcel_cipher_exit_inv(tfm, &req->base,
+					skcipher_request_ctx(req), &result);
 }
 
 static int safexcel_aead_exit_inv(struct crypto_tfm *tfm)
 {
 	EIP197_REQUEST_ON_STACK(req, aead, EIP197_AEAD_REQ_SIZE);
-	struct safexcel_cipher_req *sreq = aead_request_ctx(req);
 	struct safexcel_inv_result result = {};
 
 	memset(req, 0, sizeof(struct aead_request));
@@ -1132,7 +1131,8 @@ static int safexcel_aead_exit_inv(struct crypto_tfm *tfm)
 				  safexcel_inv_complete, &result);
 	aead_request_set_tfm(req, __crypto_aead_cast(tfm));
 
-	return safexcel_cipher_exit_inv(tfm, &req->base, sreq, &result);
+	return safexcel_cipher_exit_inv(tfm, &req->base, aead_request_ctx(req),
+					&result);
 }
 
 static int safexcel_queue_req(struct crypto_async_request *base,
-- 
2.30.2