s390/crypto: Don't panic after crypto instruction failures

Remove the BUG_ON's that check for failure or incomplete
results of the s390 hardware crypto instructions.
Rather report the errors as -EIO to the crypto layer.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/crypto/ghash_s390.c b/arch/s390/crypto/ghash_s390.c
index 1ebd3a1..d43485d 100644
--- a/arch/s390/crypto/ghash_s390.c
+++ b/arch/s390/crypto/ghash_s390.c
@@ -72,14 +72,16 @@
 		if (!dctx->bytes) {
 			ret = crypt_s390_kimd(KIMD_GHASH, ctx, buf,
 					      GHASH_BLOCK_SIZE);
-			BUG_ON(ret != GHASH_BLOCK_SIZE);
+			if (ret != GHASH_BLOCK_SIZE)
+				return -EIO;
 		}
 	}
 
 	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
 	if (n) {
 		ret = crypt_s390_kimd(KIMD_GHASH, ctx, src, n);
-		BUG_ON(ret != n);
+		if (ret != n)
+			return -EIO;
 		src += n;
 		srclen -= n;
 	}
@@ -92,7 +94,7 @@
 	return 0;
 }
 
-static void ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
+static int ghash_flush(struct ghash_ctx *ctx, struct ghash_desc_ctx *dctx)
 {
 	u8 *buf = dctx->buffer;
 	int ret;
@@ -103,21 +105,24 @@
 		memset(pos, 0, dctx->bytes);
 
 		ret = crypt_s390_kimd(KIMD_GHASH, ctx, buf, GHASH_BLOCK_SIZE);
-		BUG_ON(ret != GHASH_BLOCK_SIZE);
+		if (ret != GHASH_BLOCK_SIZE)
+			return -EIO;
 	}
 
 	dctx->bytes = 0;
+	return 0;
 }
 
 static int ghash_final(struct shash_desc *desc, u8 *dst)
 {
 	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
 	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
+	int ret;
 
-	ghash_flush(ctx, dctx);
-	memcpy(dst, ctx->icv, GHASH_BLOCK_SIZE);
-
-	return 0;
+	ret = ghash_flush(ctx, dctx);
+	if (!ret)
+		memcpy(dst, ctx->icv, GHASH_BLOCK_SIZE);
+	return ret;
 }
 
 static struct shash_alg ghash_alg = {