[PATCH v3 2/7] kunit: kunit-test: Add test cases for extending log buffer

Richard Fitzgerald
2023-08-09T15:55:08Z

Add test cases for the dynamically-extending log buffer.

kunit_log_init_frag_test() tests that kunit_init_log_frag() correctly
initializes new struct kunit_log_frag.

kunit_log_extend_test_1() logs a series of numbered lines then tests
that the resulting log contains all the lines.

kunit_log_extend_test_2() logs a large number of lines of varying length
to create many fragments, then tests that all lines are present.

kunit_log_newline_test() has a new test to append a line that is exactly
the length of the available space in the current fragment and check that
the resulting log has a trailing '\n'.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
lib/kunit/kunit-test.c | 182 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 174 insertions(+), 8 deletions(-)

diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
index a199f83bac67..c0ee33a8031e 100644
--- a/lib/kunit/kunit-test.c
+++ b/lib/kunit/kunit-test.c
@@ -7,6 +7,7 @@
*/
#include <kunit/test.h>
#include <kunit/test-bug.h>
+#include <linux/prandom.h>

#include "try-catch-impl.h"

@@ -530,10 +531,12 @@ static struct kunit_suite kunit_resource_test_suite = {
.test_cases = kunit_resource_test_cases,
};

-static char *get_concatenated_log(struct kunit *test, const struct list_head *log)
+static char *get_concatenated_log(struct kunit *test, const struct list_head *log,
+ int *num_frags)
{
struct kunit_log_frag *frag;
size_t len = 0;
+ int frag_count = 0;
char *p;

list_for_each_entry(frag, log, list)
@@ -542,24 +545,42 @@ static char *get_concatenated_log(struct kunit *test, const struct list_head *lo
len++; /* for terminating '\0' */
p = kunit_kzalloc(test, len, GFP_KERNEL);

- list_for_each_entry(frag, log, list)
+ list_for_each_entry(frag, log, list) {
strlcat(p, frag->buf, len);
+ ++frag_count;
+ }
+
+ if (num_frags)
+ *num_frags = frag_count;

return p;
}

-static void kunit_log_test(struct kunit *test)
+static void kunit_log_init_frag_test(struct kunit *test)
{
- struct kunit_suite suite;
struct kunit_log_frag *frag;

- 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);
+ memset(frag, 0x5a, sizeof(*frag));
+
kunit_init_log_frag(frag);
KUNIT_EXPECT_EQ(test, frag->buf[0], '\0');
+ KUNIT_EXPECT_TRUE(test, list_is_first(&frag->list, &frag->list));
+ KUNIT_EXPECT_TRUE(test, list_is_last(&frag->list, &frag->list));
+}
+
+static void kunit_log_test(struct kunit *test)
+{
+ struct kunit_suite suite;
+ struct kunit_log_frag *frag;
+
+ 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_kzalloc(test, sizeof(*frag), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, frag);
+ kunit_init_log_frag(frag);
list_add_tail(&frag->list, suite.log);

kunit_log(KERN_INFO, test, "put this in log.");
@@ -586,23 +607,168 @@ static void kunit_log_test(struct kunit *test)

static void kunit_log_newline_test(struct kunit *test)
{
+ struct kunit_suite suite;
struct kunit_log_frag *frag;
+ char *p;

kunit_info(test, "Add newline\n");
if (test->log) {
frag = list_first_entry(test->log, struct kunit_log_frag, list);
KUNIT_ASSERT_NOT_NULL_MSG(test, strstr(frag->buf, "Add newline\n"),
"Missing log line, full log:\n%s",
- get_concatenated_log(test, test->log));
+ get_concatenated_log(test, test->log, NULL));
KUNIT_EXPECT_NULL(test, strstr(frag->buf, "Add newline\n\n"));
+
+ 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_kzalloc(test, sizeof(*frag), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, frag);
+ kunit_init_log_frag(frag);
+ list_add_tail(&frag->list, suite.log);
+
+ /* String that exactly fills fragment leaving no room for \n */
+ memset(frag->buf, 0, sizeof(frag->buf));
+ memset(frag->buf, 'x', sizeof(frag->buf) - 9);
+ kunit_log_append(suite.log, "12345678");
+ p = get_concatenated_log(test, suite.log, NULL);
+ 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);
} else {
kunit_skip(test, "only useful when debugfs is enabled");
}
}

+static void kunit_log_extend_test_1(struct kunit *test)
+{
+#ifdef CONFIG_KUNIT_DEBUGFS
+ struct kunit_suite suite;
+ struct kunit_log_frag *frag;
+ char line[60];
+ char *p, *pn;
+ size_t len, n;
+ int num_lines, 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_kzalloc(test, sizeof(*frag), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, frag);
+ kunit_init_log_frag(frag);
+ list_add_tail(&frag->list, suite.log);
+
+ i = 0;
+ len = 0;
+ do {
+ n = snprintf(line, sizeof(line),
+ "The quick brown fox jumps over the lazy penguin %d\n", i);
+ KUNIT_ASSERT_LT(test, n, sizeof(line));
+ kunit_log_append(suite.log, line);
+ ++i;
+ len += n;
+ } while (len < (sizeof(frag->buf) * 30));
+ num_lines = i;
+
+ 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 lines:%d num_frags:%d total len:%zu\n",
+ num_lines, num_frags, strlen(p));
+
+ i = 0;
+ while ((pn = strchr(p, '\n')) != NULL) {
+ *pn = '\0';
+ snprintf(line, sizeof(line),
+ "The quick brown fox jumps over the lazy penguin %d", i);
+ KUNIT_EXPECT_STREQ(test, p, line);
+ p = pn + 1;
+ ++i;
+ }
+ KUNIT_EXPECT_EQ(test, i, num_lines);
+#else
+ kunit_skip(test, "only useful when debugfs is enabled");
+#endif
+}
+
+static void kunit_log_extend_test_2(struct kunit *test)
+{
+#ifdef CONFIG_KUNIT_DEBUGFS
+ struct kunit_suite suite;
+ struct kunit_log_frag *frag;
+ struct rnd_state rnd;
+ char line[101];
+ char *p, *pn;
+ size_t len;
+ int num_lines, num_frags, n, 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_kzalloc(test, sizeof(*frag), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, frag);
+ kunit_init_log_frag(frag);
+ list_add_tail(&frag->list, suite.log);
+
+ /* Build log line of varying content */
+ line[0] = '\0';
+ i = 0;
+ do {
+ char tmp[9];
+
+ snprintf(tmp, sizeof(tmp), "%x", i++);
+ len = strlcat(line, tmp, sizeof(line));
+ } while (len < sizeof(line) - 1);
+
+ /*
+ * Log lines of different lengths until we have created
+ * many fragments.
+ * The "randomness" must be repeatable.
+ */
+ prandom_seed_state(&rnd, 3141592653589793238ULL);
+ i = 0;
+ len = 0;
+ num_lines = 0;
+ do {
+ kunit_log_append(suite.log, "%s\n", &line[i]);
+ len += sizeof(line) - i;
+ num_lines++;
+ i = prandom_u32_state(&rnd) % (sizeof(line) - 1);
+ } while (len < (sizeof(frag->buf) * 30));
+
+ /* There must be more than one buffer fragment now */
+ KUNIT_EXPECT_FALSE(test, list_is_singular(suite.log));
+
+ 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 lines:%d num_frags:%d total len:%zu\n",
+ num_lines, num_frags, strlen(p));
+
+ prandom_seed_state(&rnd, 3141592653589793238ULL);
+ i = 0;
+ n = 0;
+ while ((pn = strchr(p, '\n')) != NULL) {
+ *pn = '\0';
+ KUNIT_EXPECT_STREQ(test, p, &line[i]);
+ p = pn + 1;
+ n++;
+ i = prandom_u32_state(&rnd) % (sizeof(line) - 1);
+ }
+ KUNIT_EXPECT_EQ_MSG(test, n, num_lines, "Not enough lines.");
+#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),
KUNIT_CASE(kunit_log_newline_test),
+ KUNIT_CASE(kunit_log_extend_test_1),
+ KUNIT_CASE(kunit_log_extend_test_2),
{}
};

--
2.30.2