crypto: drivers - Use kmemdup rather than duplicating its implementation

kmemdup is introduced to duplicate a region of memory in a neat way.
Rather than kmalloc/kzalloc + memcpy, which the programmer needs to
write the size twice (sometimes lead to mistakes), kmemdup improves
readability, leads to smaller code and also reduce the chances of mistakes.
Suggestion to use kmemdup rather than using kmalloc/kzalloc + memcpy.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/caampkc.c

@@ -867,7 +867,7 @@ static int caam_rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
 		return ret;
 
 	/* Copy key in DMA zone */
-	rsa_key->e = kzalloc(raw_key.e_sz, GFP_DMA | GFP_KERNEL);
+	rsa_key->e = kmemdup(raw_key.e, raw_key.e_sz, GFP_DMA | GFP_KERNEL);
 	if (!rsa_key->e)
 		goto err;
 
@@ -889,8 +889,6 @@ static int caam_rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
 	rsa_key->e_sz = raw_key.e_sz;
 	rsa_key->n_sz = raw_key.n_sz;
 
-	memcpy(rsa_key->e, raw_key.e, raw_key.e_sz);
-
 	return 0;
 err:
 	caam_rsa_free_key(rsa_key);
@@ -971,11 +969,11 @@ static int caam_rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
 		return ret;
 
 	/* Copy key in DMA zone */
-	rsa_key->d = kzalloc(raw_key.d_sz, GFP_DMA | GFP_KERNEL);
+	rsa_key->d = kmemdup(raw_key.d, raw_key.d_sz, GFP_DMA | GFP_KERNEL);
 	if (!rsa_key->d)
 		goto err;
 
-	rsa_key->e = kzalloc(raw_key.e_sz, GFP_DMA | GFP_KERNEL);
+	rsa_key->e = kmemdup(raw_key.e, raw_key.e_sz, GFP_DMA | GFP_KERNEL);
 	if (!rsa_key->e)
 		goto err;
 
@@ -998,9 +996,6 @@ static int caam_rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
 	rsa_key->e_sz = raw_key.e_sz;
 	rsa_key->n_sz = raw_key.n_sz;
 
-	memcpy(rsa_key->d, raw_key.d, raw_key.d_sz);
-	memcpy(rsa_key->e, raw_key.e, raw_key.e_sz);
-
 	caam_rsa_set_priv_key_form(ctx, &raw_key);
 
 	return 0;

drivers/crypto/virtio/virtio_crypto_algs.c

@@ -129,13 +129,11 @@ static int virtio_crypto_alg_ablkcipher_init_session(
 	 * Avoid to do DMA from the stack, switch to using
 	 * dynamically-allocated for the key
 	 */
-	uint8_t *cipher_key = kmalloc(keylen, GFP_ATOMIC);
+	uint8_t *cipher_key = kmemdup(key, keylen, GFP_ATOMIC);
 
 	if (!cipher_key)
 		return -ENOMEM;
 
-	memcpy(cipher_key, key, keylen);
-
 	spin_lock(&vcrypto->ctrl_lock);
 	/* Pad ctrl header */
 	vcrypto->ctrl.header.opcode =