crypto: vmx - return correct error code on failed setkey

In the VMX implementations of AES and AES modes, return -EINVAL when an
invalid key length is provided, rather than some unusual error code
determined via a series of additions.  This makes the behavior match the
other AES implementations in the kernel's crypto API.

Cc: Daniel Axtens <dja@axtens.net>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/vmx/aes.c

@@ -78,13 +78,14 @@ static int p8_aes_setkey(struct crypto_tfm *tfm, const u8 *key,
 	pagefault_disable();
 	enable_kernel_vsx();
 	ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
-	ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
+	ret |= aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
 	disable_kernel_vsx();
 	pagefault_enable();
 	preempt_enable();
 
-	ret += crypto_cipher_setkey(ctx->fallback, key, keylen);
-	return ret;
+	ret |= crypto_cipher_setkey(ctx->fallback, key, keylen);
+
+	return ret ? -EINVAL : 0;
 }
 
 static void p8_aes_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)

drivers/crypto/vmx/aes_cbc.c

@@ -81,13 +81,14 @@ static int p8_aes_cbc_setkey(struct crypto_tfm *tfm, const u8 *key,
 	pagefault_disable();
 	enable_kernel_vsx();
 	ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
-	ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
+	ret |= aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
 	disable_kernel_vsx();
 	pagefault_enable();
 	preempt_enable();
 
-	ret += crypto_sync_skcipher_setkey(ctx->fallback, key, keylen);
-	return ret;
+	ret |= crypto_sync_skcipher_setkey(ctx->fallback, key, keylen);
+
+	return ret ? -EINVAL : 0;
 }
 
 static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,

drivers/crypto/vmx/aes_ctr.c

@@ -83,8 +83,9 @@ static int p8_aes_ctr_setkey(struct crypto_tfm *tfm, const u8 *key,
 	pagefault_enable();
 	preempt_enable();
 
-	ret += crypto_sync_skcipher_setkey(ctx->fallback, key, keylen);
-	return ret;
+	ret |= crypto_sync_skcipher_setkey(ctx->fallback, key, keylen);
+
+	return ret ? -EINVAL : 0;
 }
 
 static void p8_aes_ctr_final(struct p8_aes_ctr_ctx *ctx,

drivers/crypto/vmx/aes_xts.c

@@ -86,14 +86,15 @@ static int p8_aes_xts_setkey(struct crypto_tfm *tfm, const u8 *key,
 	pagefault_disable();
 	enable_kernel_vsx();
 	ret = aes_p8_set_encrypt_key(key + keylen/2, (keylen/2) * 8, &ctx->tweak_key);
-	ret += aes_p8_set_encrypt_key(key, (keylen/2) * 8, &ctx->enc_key);
-	ret += aes_p8_set_decrypt_key(key, (keylen/2) * 8, &ctx->dec_key);
+	ret |= aes_p8_set_encrypt_key(key, (keylen/2) * 8, &ctx->enc_key);
+	ret |= aes_p8_set_decrypt_key(key, (keylen/2) * 8, &ctx->dec_key);
 	disable_kernel_vsx();
 	pagefault_enable();
 	preempt_enable();
 
-	ret += crypto_sync_skcipher_setkey(ctx->fallback, key, keylen);
-	return ret;
+	ret |= crypto_sync_skcipher_setkey(ctx->fallback, key, keylen);
+
+	return ret ? -EINVAL : 0;
 }
 
 static int p8_aes_xts_crypt(struct blkcipher_desc *desc,