[PATCH v6 09/10] kunit: Use string_stream for test log

Richard Fitzgerald
2023-08-28T10:42:03Z

Replace the fixed-size log buffer with a string_stream so that the
log can grow as lines are added.

The existing kunit log tests have been updated for using a
string_stream as the log. No new test have been added because there
are already tests for the underlying string_stream.

As the log tests now depend on string_stream functions they cannot
build when kunit-test is a module. They have been surrounded by
a #if to replace them with skipping version when the test is
build as a module. Though this isn't pretty, it avoids moving
code to another file while that code is also being changed.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: David Gow <davidgow@google.com>
---
Changes since V5:
- In kunit-test.c: add wrapper function around kfree() to prevent cast
warning when calling kunit_add_action().
- Fix unused variable warning in kunit_log_test() when built as a module.
---
include/kunit/test.h | 14 +++++------
lib/kunit/debugfs.c | 36 +++++++++++++++++----------
lib/kunit/kunit-test.c | 56 +++++++++++++++++++++++++++++++++++-------
lib/kunit/test.c | 44 ++++-----------------------------
4 files changed, 81 insertions(+), 69 deletions(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index d33114097d0d..b915a0fe93c0 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -32,9 +32,7 @@
DECLARE_STATIC_KEY_FALSE(kunit_running);

struct kunit;
-
-/* Size of log associated with test. */
-#define KUNIT_LOG_SIZE 2048
+struct string_stream;

/* Maximum size of parameter description string. */
#define KUNIT_PARAM_DESC_SIZE 128
@@ -132,7 +130,7 @@ struct kunit_case {
/* private: internal use only. */
enum kunit_status status;
char *module_name;
- char *log;
+ struct string_stream *log;
};

static inline char *kunit_status_to_ok_not_ok(enum kunit_status status)
@@ -252,7 +250,7 @@ struct kunit_suite {
/* private: internal use only */
char status_comment[KUNIT_STATUS_COMMENT_SIZE];
struct dentry *debugfs;
- char *log;
+ struct string_stream *log;
int suite_init_err;
};

@@ -278,7 +276,7 @@ struct kunit {

/* private: internal use only. */
const char *name; /* Read only after initialization! */
- char *log; /* Points at case log after initialization */
+ struct string_stream *log; /* Points at case log after initialization */
struct kunit_try_catch try_catch;
/* param_value is the current parameter value for a test case. */
const void *param_value;
@@ -314,7 +312,7 @@ const char *kunit_filter_glob(void);
char *kunit_filter(void);
char *kunit_filter_action(void);

-void kunit_init_test(struct kunit *test, const char *name, char *log);
+void kunit_init_test(struct kunit *test, const char *name, struct string_stream *log);

int kunit_run_tests(struct kunit_suite *suite);

@@ -472,7 +470,7 @@ static inline void *kunit_kcalloc(struct kunit *test, size_t n, size_t size, gfp

void kunit_cleanup(struct kunit *test);

-void __printf(2, 3) kunit_log_append(char *log, const char *fmt, ...);
+void __printf(2, 3) kunit_log_append(struct string_stream *log, const char *fmt, ...);

/**
* kunit_mark_skipped() - Marks @test_or_suite as skipped
diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
index 22c5c496a68f..270d185737e6 100644
--- a/lib/kunit/debugfs.c
+++ b/lib/kunit/debugfs.c
@@ -37,14 +37,21 @@ void kunit_debugfs_init(void)
debugfs_rootdir = debugfs_create_dir(KUNIT_DEBUGFS_ROOT, NULL);
}

-static void debugfs_print_result(struct seq_file *seq,
- struct kunit_suite *suite,
- struct kunit_case *test_case)
+static void debugfs_print_result(struct seq_file *seq, struct string_stream *log)
{
- if (!test_case || !test_case->log)
+ struct string_stream_fragment *frag_container;
+
+ if (!log)
return;

- seq_printf(seq, "%s", test_case->log);
+ /*
+ * Walk the fragments so we don't need to allocate a temporary
+ * buffer to hold the entire string.
+ */
+ spin_lock(&log->lock);
+ list_for_each_entry(frag_container, &log->fragments, node)
+ seq_printf(seq, "%s", frag_container->fragment);
+ spin_unlock(&log->lock);
}

/*
@@ -69,10 +76,9 @@ static int debugfs_print_results(struct seq_file *seq, void *v)
seq_printf(seq, KUNIT_SUBTEST_INDENT "1..%zd\n", kunit_suite_num_test_cases(suite));

kunit_suite_for_each_test_case(suite, test_case)
- debugfs_print_result(seq, suite, test_case);
+ debugfs_print_result(seq, test_case->log);

- if (suite->log)
- seq_printf(seq, "%s", suite->log);
+ debugfs_print_result(seq, suite->log);

seq_printf(seq, "%s %d %s\n",
kunit_status_to_ok_not_ok(success), 1, suite->name);
@@ -105,9 +111,13 @@ void kunit_debugfs_create_suite(struct kunit_suite *suite)
struct kunit_case *test_case;

/* Allocate logs before creating debugfs representation. */
- suite->log = kzalloc(KUNIT_LOG_SIZE, GFP_KERNEL);
- kunit_suite_for_each_test_case(suite, test_case)
- test_case->log = kzalloc(KUNIT_LOG_SIZE, GFP_KERNEL);
+ suite->log = alloc_string_stream(GFP_KERNEL);
+ string_stream_set_append_newlines(suite->log, true);
+
+ kunit_suite_for_each_test_case(suite, test_case) {
+ test_case->log = alloc_string_stream(GFP_KERNEL);
+ string_stream_set_append_newlines(test_case->log, true);
+ }

suite->debugfs = debugfs_create_dir(suite->name, debugfs_rootdir);

@@ -121,7 +131,7 @@ void kunit_debugfs_destroy_suite(struct kunit_suite *suite)
struct kunit_case *test_case;

debugfs_remove_recursive(suite->debugfs);
- kfree(suite->log);
+ string_stream_destroy(suite->log);
kunit_suite_for_each_test_case(suite, test_case)
- kfree(test_case->log);
+ string_stream_destroy(test_case->log);
}
diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
index 83d8e90ca7a2..99d2a3a528e1 100644
--- a/lib/kunit/kunit-test.c
+++ b/lib/kunit/kunit-test.c
@@ -8,6 +8,7 @@
#include <kunit/test.h>
#include <kunit/test-bug.h>

+#include "string-stream.h"
#include "try-catch-impl.h"

struct kunit_try_catch_test_context {
@@ -530,12 +531,27 @@ static struct kunit_suite kunit_resource_test_suite = {
.test_cases = kunit_resource_test_cases,
};

+/*
+ * Log tests call string_stream functions, which aren't exported. So only
+ * build this code if this test is built-in.
+ */
+#if IS_BUILTIN(CONFIG_KUNIT_TEST)
+
+/* This avoids a cast warning if kfree() is passed direct to kunit_add_action(). */
+static void kfree_wrapper(void *p)
+{
+ kfree(p);
+}
+
static void kunit_log_test(struct kunit *test)
{
struct kunit_suite suite;
-
- suite.log = kunit_kzalloc(test, KUNIT_LOG_SIZE, GFP_KERNEL);
+#ifdef CONFIG_KUNIT_DEBUGFS
+ char *full_log;
+#endif
+ suite.log = kunit_alloc_string_stream(test, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, suite.log);
+ string_stream_set_append_newlines(suite.log, true);

kunit_log(KERN_INFO, test, "put this in log.");
kunit_log(KERN_INFO, test, "this too.");
@@ -543,14 +559,21 @@ static void kunit_log_test(struct kunit *test)
kunit_log(KERN_INFO, &suite, "along with this.");

#ifdef CONFIG_KUNIT_DEBUGFS
+ KUNIT_EXPECT_TRUE(test, test->log->append_newlines);
+
+ full_log = string_stream_get_string(test->log);
+ kunit_add_action(test, (kunit_action_t *)kfree, full_log);
KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
- strstr(test->log, "put this in log."));
+ strstr(full_log, "put this in log."));
KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
- strstr(test->log, "this too."));
+ strstr(full_log, "this too."));
+
+ full_log = string_stream_get_string(suite.log);
+ kunit_add_action(test, kfree_wrapper, full_log);
KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
- strstr(suite.log, "add to suite log."));
+ strstr(full_log, "add to suite log."));
KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
- strstr(suite.log, "along with this."));
+ strstr(full_log, "along with this."));
#else
KUNIT_EXPECT_NULL(test, test->log);
#endif
@@ -558,15 +581,30 @@ static void kunit_log_test(struct kunit *test)

static void kunit_log_newline_test(struct kunit *test)
{
+ char *full_log;
+
kunit_info(test, "Add newline\n");
if (test->log) {
- KUNIT_ASSERT_NOT_NULL_MSG(test, strstr(test->log, "Add newline\n"),
- "Missing log line, full log:\n%s", test->log);
- KUNIT_EXPECT_NULL(test, strstr(test->log, "Add newline\n\n"));
+ full_log = string_stream_get_string(test->log);
+ kunit_add_action(test, kfree_wrapper, full_log);
+ KUNIT_ASSERT_NOT_NULL_MSG(test, strstr(full_log, "Add newline\n"),
+ "Missing log line, full log:\n%s", full_log);
+ KUNIT_EXPECT_NULL(test, strstr(full_log, "Add newline\n\n"));
} else {
kunit_skip(test, "only useful when debugfs is enabled");
}
}
+#else
+static void kunit_log_test(struct kunit *test)
+{
+ kunit_skip(test, "Log tests only run when built-in");
+}
+
+static void kunit_log_newline_test(struct kunit *test)
+{
+ kunit_skip(test, "Log tests only run when built-in");
+}
+#endif /* IS_BUILTIN(CONFIG_KUNIT_TEST) */

static struct kunit_case kunit_log_test_cases[] = {
KUNIT_CASE(kunit_log_test),
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 2ad45a4ac06a..b153808ff1ec 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -109,51 +109,17 @@ static void kunit_print_test_stats(struct kunit *test,
stats.total);
}

-/**
- * kunit_log_newline() - Add newline to the end of log if one is not
- * already present.
- * @log: The log to add the newline to.
- */
-static void kunit_log_newline(char *log)
-{
- int log_len, len_left;
-
- log_len = strlen(log);
- len_left = KUNIT_LOG_SIZE - log_len - 1;
-
- if (log_len > 0 && log[log_len - 1] != '\n')
- strncat(log, "\n", len_left);
-}
-
-/*
- * Append formatted message to log, size of which is limited to
- * KUNIT_LOG_SIZE bytes (including null terminating byte).
- */
-void kunit_log_append(char *log, const char *fmt, ...)
+/* Append formatted message to log. */
+void kunit_log_append(struct string_stream *log, const char *fmt, ...)
{
va_list args;
- int len, log_len, len_left;

if (!log)
return;

- log_len = strlen(log);
- len_left = KUNIT_LOG_SIZE - log_len - 1;
- if (len_left <= 0)
- return;
-
- /* Evaluate length of line to add to log */
va_start(args, fmt);
- len = vsnprintf(NULL, 0, fmt, args) + 1;
+ string_stream_vadd(log, fmt, args);
va_end(args);
-
- /* Print formatted line to the log */
- va_start(args, fmt);
- vsnprintf(log + log_len, min(len, len_left), fmt, args);
- va_end(args);
-
- /* Add newline to end of log if not already present. */
- kunit_log_newline(log);
}
EXPORT_SYMBOL_GPL(kunit_log_append);

@@ -359,14 +325,14 @@ void __kunit_do_failed_assertion(struct kunit *test,
}
EXPORT_SYMBOL_GPL(__kunit_do_failed_assertion);

-void kunit_init_test(struct kunit *test, const char *name, char *log)
+void kunit_init_test(struct kunit *test, const char *name, struct string_stream *log)
{
spin_lock_init(&test->lock);
INIT_LIST_HEAD(&test->resources);
test->name = name;
test->log = log;
if (test->log)
- test->log[0] = '\0';
+ string_stream_clear(log);
test->status = KUNIT_SUCCESS;
test->status_comment[0] = '\0';
}
--
2.30.2