[RFC PATCH 6/7] crypto: api - Increase MAX_ALGAPI_ALIGNMASK to 127

[Herbert Xu]

Previously we limited the maximum alignment mask to 63.  This
is mostly due to stack usage for shash.  This patch introduces
a separate limit for shash algorithms and increases the general
limit to 127 which is the value that we need for DMA allocations
on arm64.

Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
---

 crypto/shash.c          |    9 +++++++--
 include/crypto/algapi.h |    2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/crypto/shash.c b/crypto/shash.c
index 0a0a50cb694f0..0a10477eac060 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -18,6 +18,8 @@
 
 #include "internal.h"
 
+#define MAX_SHASH_ALIGNMASK 63
+
 static const struct crypto_type crypto_shash_type;
 
 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
@@ -100,7 +102,7 @@ static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
 	 * We cannot count on __aligned() working for large values:
 	 * https://patchwork.kernel.org/patch/9507697/
 	 */
-	u8 ubuf[MAX_ALGAPI_ALIGNMASK * 2];
+	u8 ubuf[MAX_SHASH_ALIGNMASK * 2];
 	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 	int err;
 
@@ -142,7 +144,7 @@ static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
 	 * We cannot count on __aligned() working for large values:
 	 * https://patchwork.kernel.org/patch/9507697/
 	 */
-	u8 ubuf[MAX_ALGAPI_ALIGNMASK + HASH_MAX_DIGESTSIZE];
+	u8 ubuf[MAX_SHASH_ALIGNMASK + HASH_MAX_DIGESTSIZE];
 	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
 	int err;
 
@@ -530,6 +532,9 @@ static int shash_prepare_alg(struct shash_alg *alg)
 	    alg->statesize > HASH_MAX_STATESIZE)
 		return -EINVAL;
 
+	if (base->cra_alignmask > MAX_SHASH_ALIGNMASK)
+		return -EINVAL;
+
 	if ((alg->export && !alg->import) || (alg->import && !alg->export))
 		return -EINVAL;
 
diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index cdf12e51c53a0..16cfd823ee911 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -21,7 +21,7 @@
  * algs and architectures. Ciphers have a lower maximum size.
  */
 #define MAX_ALGAPI_BLOCKSIZE		160
-#define MAX_ALGAPI_ALIGNMASK		63
+#define MAX_ALGAPI_ALIGNMASK		127
 #define MAX_CIPHER_BLOCKSIZE		16
 #define MAX_CIPHER_ALIGNMASK		15