scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/tools/perf/tests/util.c b/tools/perf/tests/util.c
new file mode 100644
index 000000000..f9abd9911
--- /dev/null
+++ b/tools/perf/tests/util.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "tests.h"
+#include "util/blake2s.h"
+#include "util/debug.h"
+
+#include <linux/compiler.h>
+#include <stdlib.h>
+#include <string2.h>
+
+static int test_strreplace(char needle, const char *haystack,
+			   const char *replace, const char *expected)
+{
+	char *new = strreplace_chars(needle, haystack, replace);
+	int ret = strcmp(new, expected);
+
+	free(new);
+	return ret == 0;
+}
+
+/* Maximum data length tested by test_blake2s() */
+#define MAX_DATA_LEN 512
+
+/*
+ * Hash length tested by test_blake2s().  BLAKE2s supports variable-length
+ * hashes.  However, the only user of BLAKE2s in 'perf' uses 20-byte hashes,
+ * matching the length of the ELF build ID field.  So that's the length we test.
+ */
+#define HASH_LEN 20
+
+/* Test the implementation of the BLAKE2s hash algorithm. */
+static int test_blake2s(void)
+{
+	u8 data[MAX_DATA_LEN];
+	u8 hash[HASH_LEN];
+	u8 hash2[HASH_LEN];
+	struct blake2s_ctx main_ctx;
+	/*
+	 * This value was generated by the following Python code:
+	 *
+	 * import hashlib
+	 *
+	 * data = bytes(i % 256 for i in range(513))
+	 * h = hashlib.blake2s(digest_size=20)
+	 * for i in range(513):
+	 *     h.update(hashlib.blake2s(data=data[:i], digest_size=20).digest())
+	 * print(h.hexdigest())
+	 */
+	static const u8 expected_hash_of_hashes[20] = {
+		0xef, 0x9b, 0x13, 0x98, 0x78, 0x8e, 0x74, 0x59, 0x9c, 0xd5,
+		0x0c, 0xf0, 0x33, 0x97, 0x79, 0x3d, 0x3e, 0xd0, 0x95, 0xa6
+	};
+	size_t i;
+
+	/* Generate MAX_DATA_LEN bytes of data. */
+	for (i = 0; i < MAX_DATA_LEN; i++)
+		data[i] = i;
+
+	blake2s_init(&main_ctx, sizeof(hash));
+	for (i = 0; i <= MAX_DATA_LEN; i++) {
+		struct blake2s_ctx ctx;
+
+		/* Compute the BLAKE2s hash of 'i' data bytes. */
+		blake2s_init(&ctx, HASH_LEN);
+		blake2s_update(&ctx, data, i);
+		blake2s_final(&ctx, hash);
+
+		/* Verify that multiple updates produce the same result. */
+		blake2s_init(&ctx, HASH_LEN);
+		blake2s_update(&ctx, data, i / 2);
+		blake2s_update(&ctx, &data[i / 2], i - (i / 2));
+		blake2s_final(&ctx, hash2);
+		TEST_ASSERT_VAL("inconsistent BLAKE2s hashes",
+				memcmp(hash, hash2, HASH_LEN) == 0);
+
+		/*
+		 * Pass the hash to another BLAKE2s context, so that we
+		 * incrementally compute the hash of all the hashes.
+		 */
+		blake2s_update(&main_ctx, hash, HASH_LEN);
+	}
+
+	/* Verify the hash of all the hashes. */
+	blake2s_final(&main_ctx, hash);
+	TEST_ASSERT_VAL("wrong BLAKE2s hashes",
+			memcmp(hash, expected_hash_of_hashes, HASH_LEN) == 0);
+	return 0;
+}
+
+static int test__blake2s_case(struct test_suite *t __maybe_unused, int subtest __maybe_unused)
+{
+	return test_blake2s();
+}
+
+static int test__strreplace(struct test_suite *t __maybe_unused, int subtest __maybe_unused)
+{
+	TEST_ASSERT_VAL("empty string", test_strreplace(' ', "", "123", ""));
+	TEST_ASSERT_VAL("no match", test_strreplace('5', "123", "4", "123"));
+	TEST_ASSERT_VAL("replace 1", test_strreplace('3', "123", "4", "124"));
+	TEST_ASSERT_VAL("replace 2", test_strreplace('a', "abcabc", "ef", "efbcefbc"));
+	TEST_ASSERT_VAL("replace long", test_strreplace('a', "abcabc", "longlong",
+							"longlongbclonglongbc"));
+
+	return 0;
+}
+
+static struct test_case tests__util[] = {
+	TEST_CASE("String replacement", strreplace),
+	TEST_CASE("BLAKE2s hash", blake2s_case),
+	{ .name = NULL, }
+};
+
+struct test_suite suite__util = {
+	.desc = "util",
+	.test_cases = tests__util,
+};