[PATCH v7 kunit-next 1/4] kunit: add debugfs /sys/kernel/debug/kunit/<suite>/results display

From: Alan Maguire
Date: Fri Mar 13 2020 - 10:45:12 EST

add debugfs support for displaying kunit test suite results; this is
especially useful for module-loaded tests to allow disentangling of
test result display from other dmesg events. debugfs support is
provided if CONFIG_KUNIT_DEBUGFS=y.

As well as printk()ing messages, we append them to a per-test log.

Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
Reviewed-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
Reviewed-by: Frank Rowand <frank.rowand@xxxxxxxx>
---
include/kunit/test.h | 54 +++++++++++++++---
lib/kunit/Kconfig | 8 +++
lib/kunit/Makefile | 4 ++
lib/kunit/debugfs.c | 116 ++++++++++++++++++++++++++++++++++++++
lib/kunit/debugfs.h | 30 ++++++++++
lib/kunit/kunit-test.c | 4 +-
lib/kunit/test.c | 147 ++++++++++++++++++++++++++++++++++++++-----------
7 files changed, 322 insertions(+), 41 deletions(-)
create mode 100644 lib/kunit/debugfs.c
create mode 100644 lib/kunit/debugfs.h

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 2dfb550..f7b2ed4c 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -81,6 +81,9 @@ struct kunit_resource {

struct kunit;

+/* Size of log associated with test. */
+#define KUNIT_LOG_SIZE 512
+
/**
* struct kunit_case - represents an individual test case.
*
@@ -123,8 +126,14 @@ struct kunit_case {

/* private: internal use only. */
bool success;
+ char *log;
};

+static inline char *kunit_status_to_string(bool status)
+{
+ return status ? "ok" : "not ok";
+}
+
/**
* KUNIT_CASE - A helper for creating a &struct kunit_case
*
@@ -157,6 +166,10 @@ struct kunit_suite {
int (*init)(struct kunit *test);
void (*exit)(struct kunit *test);
struct kunit_case *test_cases;
+
+ /* private - internal use only */
+ struct dentry *debugfs;
+ char *log;
};

/**
@@ -175,6 +188,7 @@ struct kunit {

/* private: internal use only. */
const char *name; /* Read only after initialization! */
+ char *log; /* Points at case log after initialization */
struct kunit_try_catch try_catch;
/*
* success starts as true, and may only be set to false during a
@@ -193,10 +207,19 @@ struct kunit {
struct list_head resources; /* Protected by lock. */
};

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

int kunit_run_tests(struct kunit_suite *suite);

+size_t kunit_suite_num_test_cases(struct kunit_suite *suite);
+
+unsigned int kunit_test_case_num(struct kunit_suite *suite,
+ struct kunit_case *test_case);
+
+int __kunit_test_suites_init(struct kunit_suite **suites);
+
+void __kunit_test_suites_exit(struct kunit_suite **suites);
+
/**
* kunit_test_suites() - used to register one or more &struct kunit_suite
* with KUnit.
@@ -226,20 +249,22 @@ struct kunit {
static struct kunit_suite *suites[] = { __VA_ARGS__, NULL}; \
static int kunit_test_suites_init(void) \
{ \
- unsigned int i; \
- for (i = 0; suites[i] != NULL; i++) \
- kunit_run_tests(suites[i]); \
- return 0; \
+ return __kunit_test_suites_init(suites); \
} \
late_initcall(kunit_test_suites_init); \
static void __exit kunit_test_suites_exit(void) \
{ \
- return; \
+ return __kunit_test_suites_exit(suites); \
} \
module_exit(kunit_test_suites_exit)

#define kunit_test_suite(suite) kunit_test_suites(&suite)

+#define kunit_suite_for_each_test_case(suite, test_case) \
+ for (test_case = suite->test_cases; test_case->run_case; test_case++)
+
+bool kunit_suite_has_succeeded(struct kunit_suite *suite);
+
/*
* Like kunit_alloc_resource() below, but returns the struct kunit_resource
* object that contains the allocation. This is mostly for testing purposes.
@@ -356,8 +381,21 @@ static inline void *kunit_kzalloc(struct kunit *test, size_t size, gfp_t gfp)

void kunit_cleanup(struct kunit *test);

-#define kunit_printk(lvl, test, fmt, ...) \
- printk(lvl "\t# %s: " fmt, (test)->name, ##__VA_ARGS__)
+void kunit_log_append(char *log, const char *fmt, ...);
+
+/*
+ * printk and log to per-test or per-suite log buffer. Logging only done
+ * if CONFIG_KUNIT_DEBUGFS is 'y'; if it is 'n', no log is allocated/used.
+ */
+#define kunit_log(lvl, test_or_suite, fmt, ...) \
+ do { \
+ printk(lvl fmt, ##__VA_ARGS__); \
+ kunit_log_append((test_or_suite)->log, fmt "\n", \
+ ##__VA_ARGS__); \
+ } while (0)
+
+#define kunit_printk(lvl, test, fmt, ...) \
+ kunit_log(lvl, test, "\t# %s: " fmt, (test)->name, ##__VA_ARGS__)

/**
* kunit_info() - Prints an INFO level message associated with @test.
diff --git a/lib/kunit/Kconfig b/lib/kunit/Kconfig
index 065aa16..95d12e3 100644
--- a/lib/kunit/Kconfig
+++ b/lib/kunit/Kconfig
@@ -14,6 +14,14 @@ menuconfig KUNIT

if KUNIT

+config KUNIT_DEBUGFS
+ bool "KUnit - Enable /sys/kernel/debug/kunit debugfs representation"
+ help
+ Enable debugfs representation for kunit. Currently this consists
+ of /sys/kernel/debug/kunit/<test_suite>/results files for each
+ test suite, which allow users to see results of the last test suite
+ run that occurred.
+
config KUNIT_TEST
tristate "KUnit test for KUnit"
help
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
index fab5564..724b943 100644
--- a/lib/kunit/Makefile
+++ b/lib/kunit/Makefile
@@ -5,6 +5,10 @@ kunit-objs += test.o \
assert.o \
try-catch.o

+ifeq ($(CONFIG_KUNIT_DEBUGFS),y)
+kunit-objs += debugfs.o
+endif
+
obj-$(CONFIG_KUNIT_TEST) += kunit-test.o

# string-stream-test compiles built-in only.
diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
new file mode 100644
index 0000000..9214c49
--- /dev/null
+++ b/lib/kunit/debugfs.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ * Author: Alan Maguire <alan.maguire@xxxxxxxxxx>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/module.h>
+
+#include <kunit/test.h>
+
+#include "string-stream.h"
+
+#define KUNIT_DEBUGFS_ROOT "kunit"
+#define KUNIT_DEBUGFS_RESULTS "results"
+
+/*
+ * Create a debugfs representation of test suites:
+ *
+ * Path Semantics
+ * /sys/kernel/debug/kunit/<testsuite>/results Show results of last run for
+ * testsuite
+ *
+ */
+
+static struct dentry *debugfs_rootdir;
+
+void kunit_debugfs_cleanup(void)
+{
+ debugfs_remove_recursive(debugfs_rootdir);
+}
+
+void kunit_debugfs_init(void)
+{
+ if (!debugfs_rootdir)
+ 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)
+{
+ if (!test_case || !test_case->log)
+ return;
+
+ seq_printf(seq, "%s", test_case->log);
+}
+
+/*
+ * /sys/kernel/debug/kunit/<testsuite>/results shows all results for testsuite.
+ */
+static int debugfs_print_results(struct seq_file *seq, void *v)
+{
+ struct kunit_suite *suite = (struct kunit_suite *)seq->private;
+ bool success = kunit_suite_has_succeeded(suite);
+ struct kunit_case *test_case;
+
+ if (!suite || !suite->log)
+ return 0;
+
+ seq_printf(seq, "%s", suite->log);
+
+ kunit_suite_for_each_test_case(suite, test_case)
+ debugfs_print_result(seq, suite, test_case);
+
+ seq_printf(seq, "%s %d - %s\n",
+ kunit_status_to_string(success), 1, suite->name);
+ return 0;
+}
+
+static int debugfs_release(struct inode *inode, struct file *file)
+{
+ return single_release(inode, file);
+}
+
+static int debugfs_results_open(struct inode *inode, struct file *file)
+{
+ struct kunit_suite *suite;
+
+ suite = (struct kunit_suite *)inode->i_private;
+
+ return single_open(file, debugfs_print_results, suite);
+}
+
+static const struct file_operations debugfs_results_fops = {
+ .open = debugfs_results_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = debugfs_release,
+};
+
+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->debugfs = debugfs_create_dir(suite->name, debugfs_rootdir);
+
+ debugfs_create_file(KUNIT_DEBUGFS_RESULTS, S_IFREG | 0444,
+ suite->debugfs,
+ suite, &debugfs_results_fops);
+}
+
+void kunit_debugfs_destroy_suite(struct kunit_suite *suite)
+{
+ struct kunit_case *test_case;
+
+ debugfs_remove_recursive(suite->debugfs);
+ kfree(suite->log);
+ kunit_suite_for_each_test_case(suite, test_case)
+ kfree(test_case->log);
+}
diff --git a/lib/kunit/debugfs.h b/lib/kunit/debugfs.h
new file mode 100644
index 0000000..dcc7d75
--- /dev/null
+++ b/lib/kunit/debugfs.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020, Oracle and/or its affiliates.
+ */
+
+#ifndef _KUNIT_DEBUGFS_H
+#define _KUNIT_DEBUGFS_H
+
+#include <kunit/test.h>
+
+#ifdef CONFIG_KUNIT_DEBUGFS
+
+void kunit_debugfs_create_suite(struct kunit_suite *suite);
+void kunit_debugfs_destroy_suite(struct kunit_suite *suite);
+void kunit_debugfs_init(void);
+void kunit_debugfs_cleanup(void);
+
+#else
+
+static inline void kunit_debugfs_create_suite(struct kunit_suite *suite) { }
+
+static inline void kunit_debugfs_destroy_suite(struct kunit_suite *suite) { }
+
+static inline void kunit_debugfs_init(void) { }
+
+static inline void kunit_debugfs_cleanup(void) { }
+
+#endif /* CONFIG_KUNIT_DEBUGFS */
+
+#endif /* _KUNIT_DEBUGFS_H */
diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
index ccb8d2e..aceb5bf 100644
--- a/lib/kunit/kunit-test.c
+++ b/lib/kunit/kunit-test.c
@@ -134,7 +134,7 @@ static void kunit_resource_test_init_resources(struct kunit *test)
{
struct kunit_test_resource_context *ctx = test->priv;

- kunit_init_test(&ctx->test, "testing_test_init_test");
+ kunit_init_test(&ctx->test, "testing_test_init_test", NULL);

KUNIT_EXPECT_TRUE(test, list_empty(&ctx->test.resources));
}
@@ -301,7 +301,7 @@ static int kunit_resource_test_init(struct kunit *test)

test->priv = ctx;

- kunit_init_test(&ctx->test, "test_test_context");
+ kunit_init_test(&ctx->test, "test_test_context", NULL);

return 0;
}
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 9242f93..a3fa21f 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -10,6 +10,7 @@
#include <linux/kernel.h>
#include <linux/sched/debug.h>

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

@@ -28,73 +29,116 @@ static void kunit_print_tap_version(void)
}
}

-static size_t kunit_test_cases_len(struct kunit_case *test_cases)
+/*
+ * 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, ...)
+{
+ char line[KUNIT_LOG_SIZE];
+ va_list args;
+ int len_left;
+
+ if (!log)
+ return;
+
+ len_left = KUNIT_LOG_SIZE - strlen(log) - 1;
+ if (len_left <= 0)
+ return;
+
+ va_start(args, fmt);
+ vsnprintf(line, sizeof(line), fmt, args);
+ va_end(args);
+
+ strncat(log, line, len_left);
+}
+EXPORT_SYMBOL_GPL(kunit_log_append);
+
+size_t kunit_suite_num_test_cases(struct kunit_suite *suite)
{
struct kunit_case *test_case;
size_t len = 0;

- for (test_case = test_cases; test_case->run_case; test_case++)
+ kunit_suite_for_each_test_case(suite, test_case)
len++;

return len;
}
+EXPORT_SYMBOL_GPL(kunit_suite_num_test_cases);

static void kunit_print_subtest_start(struct kunit_suite *suite)
{
kunit_print_tap_version();
- pr_info("\t# Subtest: %s\n", suite->name);
- pr_info("\t1..%zd\n", kunit_test_cases_len(suite->test_cases));
+ kunit_log(KERN_INFO, suite, "\t# Subtest: %s", suite->name);
+ kunit_log(KERN_INFO, suite, "\t1..%zd",
+ kunit_suite_num_test_cases(suite));
}

-static void kunit_print_ok_not_ok(bool should_indent,
+static void kunit_print_ok_not_ok(void *test_or_suite,
+ bool is_test,
bool is_ok,
size_t test_number,
const char *description)
{
- const char *indent, *ok_not_ok;
-
- if (should_indent)
- indent = "\t";
- else
- indent = "";
+ struct kunit_suite *suite = is_test ? NULL : test_or_suite;
+ struct kunit *test = is_test ? test_or_suite : NULL;

- if (is_ok)
- ok_not_ok = "ok";
+ /*
+ * We do not log the test suite results as doing so would
+ * mean debugfs display would consist of the test suite
+ * description and status prior to individual test results.
+ * Hence directly printk the suite status, and we will
+ * separately seq_printf() the suite status for the debugfs
+ * representation.
+ */
+ if (suite)
+ pr_info("%s %zd - %s",
+ kunit_status_to_string(is_ok),
+ test_number, description);
else
- ok_not_ok = "not ok";
-
- pr_info("%s%s %zd - %s\n", indent, ok_not_ok, test_number, description);
+ kunit_log(KERN_INFO, test, "\t%s %zd - %s",
+ kunit_status_to_string(is_ok),
+ test_number, description);
}

-static bool kunit_suite_has_succeeded(struct kunit_suite *suite)
+bool kunit_suite_has_succeeded(struct kunit_suite *suite)
{
const struct kunit_case *test_case;

- for (test_case = suite->test_cases; test_case->run_case; test_case++)
+ kunit_suite_for_each_test_case(suite, test_case) {
if (!test_case->success)
return false;
+ }

return true;
}
+EXPORT_SYMBOL_GPL(kunit_suite_has_succeeded);

static void kunit_print_subtest_end(struct kunit_suite *suite)
{
static size_t kunit_suite_counter = 1;

- kunit_print_ok_not_ok(false,
+ kunit_print_ok_not_ok((void *)suite, false,
kunit_suite_has_succeeded(suite),
kunit_suite_counter++,
suite->name);
}

-static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
- size_t test_number)
+unsigned int kunit_test_case_num(struct kunit_suite *suite,
+ struct kunit_case *test_case)
{
- kunit_print_ok_not_ok(true,
- test_case->success,
- test_number,
- test_case->name);
+ struct kunit_case *tc;
+ unsigned int i = 1;
+
+ kunit_suite_for_each_test_case(suite, tc) {
+ if (tc == test_case)
+ return i;
+ i++;
+ }
+
+ return 0;
}
+EXPORT_SYMBOL_GPL(kunit_test_case_num);

static void kunit_print_string_stream(struct kunit *test,
struct string_stream *stream)
@@ -102,6 +146,9 @@ static void kunit_print_string_stream(struct kunit *test,
struct string_stream_fragment *fragment;
char *buf;

+ if (string_stream_is_empty(stream))
+ return;
+
buf = string_stream_get_string(stream);
if (!buf) {
kunit_err(test,
@@ -175,11 +222,14 @@ void kunit_do_assertion(struct kunit *test,
}
EXPORT_SYMBOL_GPL(kunit_do_assertion);

-void kunit_init_test(struct kunit *test, const char *name)
+void kunit_init_test(struct kunit *test, const char *name, char *log)
{
spin_lock_init(&test->lock);
INIT_LIST_HEAD(&test->resources);
test->name = name;
+ test->log = log;
+ if (test->log)
+ test->log[0] = '\0';
test->success = true;
}
EXPORT_SYMBOL_GPL(kunit_init_test);
@@ -290,7 +340,7 @@ static void kunit_run_case_catch_errors(struct kunit_suite *suite,
struct kunit_try_catch *try_catch;
struct kunit test;

- kunit_init_test(&test, test_case->name);
+ kunit_init_test(&test, test_case->name, test_case->log);
try_catch = &test.try_catch;

kunit_try_catch_init(try_catch,
@@ -303,19 +353,20 @@ static void kunit_run_case_catch_errors(struct kunit_suite *suite,
kunit_try_catch_run(try_catch, &context);

test_case->success = test.success;
+
+ kunit_print_ok_not_ok(&test, true, test_case->success,
+ kunit_test_case_num(suite, test_case),
+ test_case->name);
}

int kunit_run_tests(struct kunit_suite *suite)
{
struct kunit_case *test_case;
- size_t test_case_count = 1;

kunit_print_subtest_start(suite);

- for (test_case = suite->test_cases; test_case->run_case; test_case++) {
+ kunit_suite_for_each_test_case(suite, test_case)
kunit_run_case_catch_errors(suite, test_case);
- kunit_print_test_case_ok_not_ok(test_case, test_case_count++);
- }

kunit_print_subtest_end(suite);

@@ -323,6 +374,37 @@ int kunit_run_tests(struct kunit_suite *suite)
}
EXPORT_SYMBOL_GPL(kunit_run_tests);

+static void kunit_init_suite(struct kunit_suite *suite)
+{
+ kunit_debugfs_create_suite(suite);
+}
+
+int __kunit_test_suites_init(struct kunit_suite **suites)
+{
+ unsigned int i;
+
+ for (i = 0; suites[i] != NULL; i++) {
+ kunit_init_suite(suites[i]);
+ kunit_run_tests(suites[i]);
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__kunit_test_suites_init);
+
+static void kunit_exit_suite(struct kunit_suite *suite)
+{
+ kunit_debugfs_destroy_suite(suite);
+}
+
+void __kunit_test_suites_exit(struct kunit_suite **suites)
+{
+ unsigned int i;
+
+ for (i = 0; suites[i] != NULL; i++)
+ kunit_exit_suite(suites[i]);
+}
+EXPORT_SYMBOL_GPL(__kunit_test_suites_exit);
+
struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
kunit_resource_init_t init,
kunit_resource_free_t free,
@@ -489,12 +571,15 @@ void kunit_cleanup(struct kunit *test)

static int __init kunit_init(void)
{
+ kunit_debugfs_init();
+
return 0;
}
late_initcall(kunit_init);

static void __exit kunit_exit(void)
{
+ kunit_debugfs_cleanup();
}
module_exit(kunit_exit);

--
1.8.3.1