From 5427d3d772a77a4d67fece057064832ec5cfa078 Mon Sep 17 00:00:00 2001
From: Isabella Basso <isabbasso@riseup.net>
Date: Wed, 19 Jan 2022 18:09:09 -0800
Subject: [PATCH] test_hash.c: split test_hash_init
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Split up test_hash_init so that it calls each test more explicitly
insofar it is possible without rewriting the entire file.  This aims at
improving readability.

Split tests performed on string_or as they don't interfere with those
performed in hash_or.  Also separate pr_info calls about skipped tests
as they're not part of the tests themselves, but only warn about
(un)defined arch-specific hash functions.

Link: https://lkml.kernel.org/r/20211208183711.390454-4-isabbasso@riseup.net
Reviewed-by: David Gow <davidgow@google.com>
Tested-by: David Gow <davidgow@google.com>
Signed-off-by: Isabella Basso <isabbasso@riseup.net>
Cc: Augusto Durães Camargo <augusto.duraes33@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Enzo Ferreira <ferreiraenzoa@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: kernel test robot <lkp@intel.com>
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 lib/test_hash.c | 66 ++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 54 insertions(+), 12 deletions(-)

diff --git a/lib/test_hash.c b/lib/test_hash.c
index 2b4fe4976cc4..032849a48da7 100644
--- a/lib/test_hash.c
+++ b/lib/test_hash.c
@@ -158,11 +158,39 @@ test_int_hash(unsigned long long h64, u32 hash_or[2][33])
 
 #define SIZE 256	/* Run time is cubic in SIZE */
 
-static int __init
-test_hash_init(void)
+static int __init test_string_or(void)
 {
 	char buf[SIZE+1];
-	u32 string_or = 0, hash_or[2][33] = { { 0, } };
+	u32 string_or = 0;
+	int i, j;
+
+	fill_buf(buf, SIZE, 1);
+
+	/* Test every possible non-empty substring in the buffer. */
+	for (j = SIZE; j > 0; --j) {
+		buf[j] = '\0';
+
+		for (i = 0; i <= j; i++) {
+			u32 h0 = full_name_hash(buf+i, buf+i, j-i);
+
+			string_or |= h0;
+		} /* i */
+	} /* j */
+
+	/* The OR of all the hash values should cover all the bits */
+	if (~string_or) {
+		pr_err("OR of all string hash results = %#x != %#x",
+		       string_or, -1u);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int __init test_hash_or(void)
+{
+	char buf[SIZE+1];
+	u32 hash_or[2][33] = { { 0, } };
 	unsigned tests = 0;
 	unsigned long long h64 = 0;
 	int i, j;
@@ -192,7 +220,6 @@ test_hash_init(void)
 				return -EINVAL;
 			}
 
-			string_or |= h0;
 			h64 = h64 << 32 | h0;	/* For use with hash_64 */
 			if (!test_int_hash(h64, hash_or))
 				return -EINVAL;
@@ -200,12 +227,6 @@ test_hash_init(void)
 		} /* i */
 	} /* j */
 
-	/* The OR of all the hash values should cover all the bits */
-	if (~string_or) {
-		pr_err("OR of all string hash results = %#x != %#x",
-			string_or, -1u);
-		return -EINVAL;
-	}
 	if (~hash_or[0][0]) {
 		pr_err("OR of all __hash_32 results = %#x != %#x",
 			hash_or[0][0], -1u);
@@ -237,6 +258,13 @@ test_hash_init(void)
 		}
 	}
 
+	pr_notice("%u tests passed.", tests);
+
+	return 0;
+}
+
+static void __init notice_skipped_tests(void)
+{
 	/* Issue notices about skipped tests. */
 #ifdef HAVE_ARCH__HASH_32
 #if HAVE_ARCH__HASH_32 != 1
@@ -252,10 +280,24 @@ test_hash_init(void)
 #else
 	pr_info("hash_64() has no arch implementation to test.");
 #endif
+}
 
-	pr_notice("%u tests passed.", tests);
+static int __init
+test_hash_init(void)
+{
+	int ret;
 
-	return 0;
+	ret = test_string_or();
+	if (ret < 0)
+		return ret;
+
+	ret = test_hash_or();
+	if (ret < 0)
+		return ret;
+
+	notice_skipped_tests();
+
+	return ret;
 }
 
 static void __exit test_hash_exit(void)