Re: [PATCH v3 5/7] kunit: kunit-test: Add test cases for logging very long lines

On Wed, Aug 9, 2023 at 10:54 AM Richard Fitzgerald rf@opensource.cirrus.com wrote:

Add kunit_log_long_line_test() to test that logging a line longer than the buffer fragment size doesn't truncate the line.

Add extra tests to kunit_log_newline_test() for lines longer than the buffer fragment size.

Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com

Hello!

This test looks good to me. I have included just a few comments below.

Reviewed-by: Rae Moar rmoar@google.com

Thanks! -Rae

---

lib/kunit/kunit-test.c | 84 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 83 insertions(+), 1 deletion(-)

diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c index 9ac81828d018..c079550c3afd 100644 --- a/lib/kunit/kunit-test.c +++ b/lib/kunit/kunit-test.c @@ -609,7 +609,7 @@ static void kunit_log_newline_test(struct kunit *test) { struct kunit_suite suite; struct kunit_log_frag *frag;

•   char *p;
  

•   char *p, *line;
  
    kunit_info(test, "Add newline\n");
    if (test->log) {
  

@@ -635,6 +635,33 @@ static void kunit_log_newline_test(struct kunit *test) KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p); KUNIT_EXPECT_NOT_NULL_MSG(test, strstr(p, "x12345678\n"), "Newline not appended when fragment is full. Log is:\n'%s'", p);

•           kunit_kfree(test, p);
  

I really like the thoroughness of this test. However, I do wonder if this newline test could be broken into at least 2 parts as the test is quite long with all these additions. I spoke on this in a previous patch and just wanted to touch on it here as well.

•           /* String that is much longer than a fragment */
  

•           line = kunit_kzalloc(test, sizeof(frag->buf) * 6, GFP_KERNEL);
  

•           KUNIT_ASSERT_NOT_ERR_OR_NULL(test, line);
  

•           memset(line, 'x', (sizeof(frag->buf) * 6) - 1);
  

•           kunit_log_append(suite.log, "%s", line);
  

•           p = get_concatenated_log(test, suite.log, NULL);
  

•           KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p);
  

•           KUNIT_EXPECT_EQ(test, p[strlen(p) - 1], '\n');
  

•           KUNIT_EXPECT_NULL(test, strstr(p, "\n\n"));
  

•           kunit_kfree(test, p);
  

I would also consider adding comments between these three cases to describe their differences and maybe what the desired behavior would be.

•           kunit_log_append(suite.log, "%s\n", line);
  

•           p = get_concatenated_log(test, suite.log, NULL);
  

•           KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p);
  

•           KUNIT_EXPECT_EQ(test, p[strlen(p) - 1], '\n');
  

•           KUNIT_EXPECT_NULL(test, strstr(p, "\n\n"));
  

•           kunit_kfree(test, p);
  

•           line[strlen(line) - 1] = '\n';
  

•           kunit_log_append(suite.log, "%s", line);
  

•           p = get_concatenated_log(test, suite.log, NULL);
  

•           KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p);
  

•           KUNIT_EXPECT_EQ(test, p[strlen(p) - 1], '\n');
  

•           KUNIT_EXPECT_NULL(test, strstr(p, "\n\n"));
  

•           kunit_kfree(test, p);
    } else {
            kunit_skip(test, "only useful when debugfs is enabled");
    }
  

@@ -799,6 +826,60 @@ static void kunit_log_frag_sized_line_test(struct kunit *test) #endif }

+static void kunit_log_long_line_test(struct kunit *test) +{ +#ifdef CONFIG_KUNIT_DEBUGFS

•   struct kunit_suite suite;
  

•   struct kunit_log_frag *frag;
  

•   struct rnd_state rnd;
  

•   char *line, *p, *pn;
  

•   size_t line_buf_size, len;
  

•   int num_frags, i;
  

•   suite.log = kunit_kzalloc(test, sizeof(*suite.log), GFP_KERNEL);
  

•   KUNIT_ASSERT_NOT_ERR_OR_NULL(test, suite.log);
  

•   INIT_LIST_HEAD(suite.log);
  

•   frag = kunit_kmalloc(test, sizeof(*frag), GFP_KERNEL);
  

•   KUNIT_ASSERT_NOT_ERR_OR_NULL(test, frag);
  

•   kunit_init_log_frag(frag);
  

•   KUNIT_EXPECT_EQ(test, frag->buf[0], '\0');
  

•   list_add_tail(&frag->list, suite.log);
  

•   /* Create a very long string to be logged */
  

•   line_buf_size = sizeof(frag->buf) * 6;
  

•   line = kunit_kmalloc(test, line_buf_size, GFP_KERNEL);
  

•   KUNIT_ASSERT_NOT_ERR_OR_NULL(test, line);
  

•   line[0] = '\0';
  

•   prandom_seed_state(&rnd, 3141592653589793238ULL);
  

I was a little worried about including a randomized string but since it does not need to be reproduced here it should be fine. I also haven't seen any issues with the tests with the randomized strings being nondeterministic.

•   len = 0;
  

•   do {
  

•           static const char fill[] =
  

•                   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
  

•           i = prandom_u32_state(&rnd) % (sizeof(fill) - 1);
  

•           len = strlcat(line, &fill[i], line_buf_size);
  

•   } while (len < line_buf_size);
  

•   kunit_log_append(suite.log, "%s\n", line);
  

•   p = get_concatenated_log(test, suite.log, &num_frags);
  

•   KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p);
  

•   KUNIT_EXPECT_GT(test, num_frags, 1);
  

•   kunit_info(test, "num_frags:%d total len:%zu\n", num_frags, strlen(p));
  

•   /* Don't compare the trailing '\n' */
  

•   pn = strrchr(p, '\n');
  

•   KUNIT_EXPECT_NOT_ERR_OR_NULL(test, pn);
  

•   *pn = '\0';
  

•   KUNIT_EXPECT_EQ(test, strlen(p), strlen(line));
  

•   KUNIT_EXPECT_STREQ(test, p, line);
  

+#else

•   kunit_skip(test, "only useful when debugfs is enabled");
  

+#endif +}

static struct kunit_case kunit_log_test_cases[] = { KUNIT_CASE(kunit_log_init_frag_test), KUNIT_CASE(kunit_log_test), @@ -806,6 +887,7 @@ static struct kunit_case kunit_log_test_cases[] = { KUNIT_CASE(kunit_log_extend_test_1), KUNIT_CASE(kunit_log_extend_test_2), KUNIT_CASE(kunit_log_frag_sized_line_test),

•   KUNIT_CASE(kunit_log_long_line_test),
    {}
  

};

-- 2.30.2