Replace KUnit tests for memcmp() with KUNIT_EXPECT_MEMEQ_MSG() to improve
debugging that prints the hex dump of the buffers when the assertion fails,
whereas memcmp() only returns an integer difference.

Signed-off-by: Ryota Sakamoto <sakamo.ryota@gmail.com>
---
 net/sunrpc/auth_gss/gss_krb5_test.c | 93 ++++++++++++++++++++-----------------
 1 file changed, 51 insertions(+), 42 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_krb5_test.c b/net/sunrpc/auth_gss/gss_krb5_test.c
index a5bff02cd7ba48c75a6d270b6584c0f23cb71380..dde1ee934d0d448fe558a633e3d729c490ea26ae 100644
--- a/net/sunrpc/auth_gss/gss_krb5_test.c
+++ b/net/sunrpc/auth_gss/gss_krb5_test.c
@@ -63,10 +63,11 @@ static void kdf_case(struct kunit *test)
 	KUNIT_ASSERT_EQ(test, err, 0);
 
 	/* Assert */
-	KUNIT_EXPECT_EQ_MSG(test,
-			    memcmp(param->expected_result->data,
-				   derivedkey.data, derivedkey.len), 0,
-			    "key mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->expected_result->data,
+			       derivedkey.data,
+			       derivedkey.len,
+			       "key mismatch");
 }
 
 static void checksum_case(struct kunit *test)
@@ -111,10 +112,11 @@ static void checksum_case(struct kunit *test)
 	KUNIT_ASSERT_EQ(test, err, 0);
 
 	/* Assert */
-	KUNIT_EXPECT_EQ_MSG(test,
-			    memcmp(param->expected_result->data,
-				   checksum.data, checksum.len), 0,
-			    "checksum mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->expected_result->data,
+			       checksum.data,
+			       checksum.len,
+			       "checksum mismatch");
 
 	crypto_free_ahash(tfm);
 }
@@ -314,10 +316,11 @@ static void rfc3961_nfold_case(struct kunit *test)
 		   param->expected_result->len * 8, result);
 
 	/* Assert */
-	KUNIT_EXPECT_EQ_MSG(test,
-			    memcmp(param->expected_result->data,
-				   result, param->expected_result->len), 0,
-			    "result mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->expected_result->data,
+			       result,
+			       param->expected_result->len,
+			       "result mismatch");
 }
 
 static struct kunit_case rfc3961_test_cases[] = {
@@ -569,14 +572,16 @@ static void rfc3962_encrypt_case(struct kunit *test)
 	KUNIT_EXPECT_EQ_MSG(test,
 			    param->expected_result->len, buf.len,
 			    "ciphertext length mismatch");
-	KUNIT_EXPECT_EQ_MSG(test,
-			    memcmp(param->expected_result->data,
-				   text, param->expected_result->len), 0,
-			    "ciphertext mismatch");
-	KUNIT_EXPECT_EQ_MSG(test,
-			    memcmp(param->next_iv->data, iv,
-				   param->next_iv->len), 0,
-			    "IV mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->expected_result->data,
+			       text,
+			       param->expected_result->len,
+			       "ciphertext mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->next_iv->data,
+			       iv,
+			       param->next_iv->len,
+			       "IV mismatch");
 
 	crypto_free_sync_skcipher(cts_tfm);
 	crypto_free_sync_skcipher(cbc_tfm);
@@ -1194,15 +1199,17 @@ static void rfc6803_encrypt_case(struct kunit *test)
 	KUNIT_EXPECT_EQ_MSG(test, param->expected_result->len,
 			    buf.len + checksum.len,
 			    "ciphertext length mismatch");
-	KUNIT_EXPECT_EQ_MSG(test,
-			    memcmp(param->expected_result->data,
-				   buf.head[0].iov_base, buf.len), 0,
-			    "encrypted result mismatch");
-	KUNIT_EXPECT_EQ_MSG(test,
-			    memcmp(param->expected_result->data +
-				   (param->expected_result->len - checksum.len),
-				   checksum.data, checksum.len), 0,
-			    "HMAC mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->expected_result->data,
+			       buf.head[0].iov_base,
+			       buf.len,
+			       "encrypted result mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->expected_result->data +
+					(param->expected_result->len - checksum.len),
+			       checksum.data,
+			       checksum.len,
+			       "HMAC mismatch");
 
 	crypto_free_ahash(ahash_tfm);
 	crypto_free_sync_skcipher(cts_tfm);
@@ -1687,15 +1694,16 @@ static void rfc8009_encrypt_case(struct kunit *test)
 	KUNIT_EXPECT_EQ_MSG(test,
 			    param->expected_result->len, buf.len,
 			    "ciphertext length mismatch");
-	KUNIT_EXPECT_EQ_MSG(test,
-			    memcmp(param->expected_result->data,
-				   buf.head[0].iov_base,
-				   param->expected_result->len), 0,
-			    "ciphertext mismatch");
-	KUNIT_EXPECT_EQ_MSG(test, memcmp(param->expected_hmac->data,
-					 checksum.data,
-					 checksum.len), 0,
-			    "HMAC mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->expected_result->data,
+			       buf.head[0].iov_base,
+			       param->expected_result->len,
+			       "ciphertext mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->expected_hmac->data,
+			       checksum.data,
+			       checksum.len,
+			       "HMAC mismatch");
 
 	crypto_free_ahash(ahash_tfm);
 	crypto_free_sync_skcipher(cts_tfm);
@@ -1826,10 +1834,11 @@ static void encrypt_selftest_case(struct kunit *test)
 	KUNIT_EXPECT_EQ_MSG(test,
 			    param->plaintext->len, buf.len,
 			    "length mismatch");
-	KUNIT_EXPECT_EQ_MSG(test,
-			    memcmp(param->plaintext->data,
-				   buf.head[0].iov_base, buf.len), 0,
-			    "plaintext mismatch");
+	KUNIT_EXPECT_MEMEQ_MSG(test,
+			       param->plaintext->data,
+			       buf.head[0].iov_base,
+			       buf.len,
+			       "plaintext mismatch");
 
 	crypto_free_sync_skcipher(cts_tfm);
 	crypto_free_sync_skcipher(cbc_tfm);

---
base-commit: 62085877ae6592be830c2267e35dc469cb706308
change-id: 20260124-fix-gcc_krb5-memcmp-2156897e6be1

Best regards,
-- 
Ryota Sakamoto <sakamo.ryota@gmail.com>

From: Chuck Lever <chuck.lever@oracle.com>

On Sat, 24 Jan 2026 14:17:19 +0900, Ryota Sakamoto wrote:
> Replace KUnit tests for memcmp() with KUNIT_EXPECT_MEMEQ_MSG() to improve
> debugging that prints the hex dump of the buffers when the assertion fails,
> whereas memcmp() only returns an integer difference.
> 
> 

Applied to nfsd-testing, thanks!

[1/1] SUNRPC: Replace KUnit tests for memcmp() with KUNIT_EXPECT_MEMEQ_MSG()
      commit: 63c04545fa093cd399132519a974fca2f1e9aaea

--
Chuck Lever