[PATCH] lib/atomic64_test.c: convert to use KUnit

Daniel Latypov
2022-05-02T19:23:51Z

The test currently is a bunch of checks (implemented using BUG_ON())
that can be built into the kernel or as a module.

Convert it to a KUnit test, which can also run in both modes.
From a user's perspective, this change adds a CONFIG_KUNIT=y dep and
changes the output format of the test [1]. The test itself is the same.

This hopefully makes the test easier to run and more consistent with
similar tests in lib/.
Since it has no dependencies, it can be run without explicitly setting
up a .kunitconfig via
$ ./tools/testing/kunit/kunit.py run atomic
...
[13:53:44] Starting KUnit Kernel (1/1)...
[13:53:44] ============================================================
[13:53:47] =================== atomic (2 subtests) ====================
[13:53:47] [PASSED] test_atomic
[13:53:47] [PASSED] test_atomic64
[13:53:47] ===================== [PASSED] atomic ======================
[13:53:47] ============================================================
[13:53:47] Testing complete. Passed: 2, Failed: 0, Crashed: 0, Skipped: 0, Errors: 0
[13:53:47] Elapsed time: 13.902s total, 1.629s configuring, 9.331s building, 2.852s running

It can be run on ARCH=x86_64 (and others) via:
$ ./tools/testing/kunit/kunit.py run --arch=x86_64 atomic

The message about which platform the test ran on won't show up in
kunit.py, but still gets printed out in dmesg, e.g.
> TAP version 14
> 1..1
> # Subtest: atomic
> 1..2
> ok 1 - test_atomic
> ok 2 - test_atomic64
> # atomic: ran on x86-64 platform with CX8 and with SSE
> # atomic: pass:2 fail:0 skip:0 total:2
> # Totals: pass:2 fail:0 skip:0 total:2
> ok 1 - atomic

Signed-off-by: Daniel Latypov <dlatypov@google.com>

[1] https://www.kernel.org/doc/html/latest/dev-tools/ktap.html
---
Meta:
1. this patch applies on top of the kunit branch,
https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/?h=kunit

2. checkpatch complains about aligning with parens, but it wants me to
indent the `#ifdef CONFIG_X86_64` which seems inappropriate in context.

3. this file doesn't seem to have a clear maintainer, so I assume this
conversion is fine to go through the kunit branch. The only observable
differences are the new CONFIG_KUNIT=y dep and more standardized (KTAP)
output format.
---
lib/Kconfig.debug | 4 +-
lib/atomic64_test.c | 107 +++++++++++++++++++++-----------------------
2 files changed, 55 insertions(+), 56 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 075cd25363ac..4cf8d5feda0a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2223,7 +2223,9 @@ config PERCPU_TEST
If unsure, say N.

config ATOMIC64_SELFTEST
- tristate "Perform an atomic64_t self-test"
+ tristate "Perform an atomic64_t self-test" if !KUNIT_ALL_TESTS
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
help
Enable this option to test the atomic64_t functions at boot or
at module load time.
diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c
index d9d170238165..46cb0130f8d0 100644
--- a/lib/atomic64_test.c
+++ b/lib/atomic64_test.c
@@ -5,13 +5,9 @@
* Copyright © 2010 Luca Barbieri
*/

-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <kunit/test.h>

-#include <linux/init.h>
-#include <linux/bug.h>
-#include <linux/kernel.h>
#include <linux/atomic.h>
-#include <linux/module.h>

#ifdef CONFIG_X86
#include <asm/cpufeature.h> /* for boot_cpu_has below */
@@ -23,9 +19,7 @@ do { \
r = v0; \
atomic##bit##_##op(val, &v); \
r c_op val; \
- WARN(atomic##bit##_read(&v) != r, "%Lx != %Lx\n", \
- (unsigned long long)atomic##bit##_read(&v), \
- (unsigned long long)r); \
+ KUNIT_ASSERT_EQ(test, atomic##bit##_read(&v), r); \
} while (0)

/*
@@ -46,8 +40,8 @@ do { \
atomic##bit##_set(&v, v0); \
r = v0; \
r c_op val; \
- BUG_ON(atomic##bit##_##op(val, &v) != r); \
- BUG_ON(atomic##bit##_read(&v) != r); \
+ KUNIT_ASSERT_EQ(test, atomic##bit##_##op(val, &v), r); \
+ KUNIT_ASSERT_EQ(test, atomic##bit##_read(&v), r); \
} while (0)

#define TEST_FETCH(bit, op, c_op, val) \
@@ -55,8 +49,8 @@ do { \
atomic##bit##_set(&v, v0); \
r = v0; \
r c_op val; \
- BUG_ON(atomic##bit##_##op(val, &v) != v0); \
- BUG_ON(atomic##bit##_read(&v) != r); \
+ KUNIT_ASSERT_EQ(test, atomic##bit##_##op(val, &v), v0); \
+ KUNIT_ASSERT_EQ(test, atomic##bit##_read(&v), r); \
} while (0)

#define RETURN_FAMILY_TEST(bit, op, c_op, val) \
@@ -72,8 +66,8 @@ do { \
#define TEST_ARGS(bit, op, init, ret, expect, args...) \
do { \
atomic##bit##_set(&v, init); \
- BUG_ON(atomic##bit##_##op(&v, ##args) != ret); \
- BUG_ON(atomic##bit##_read(&v) != expect); \
+ KUNIT_ASSERT_EQ(test, atomic##bit##_##op(&v, ##args), ret);\
+ KUNIT_ASSERT_EQ(test, atomic##bit##_read(&v), expect); \
} while (0)

#define XCHG_FAMILY_TEST(bit, init, new) \
@@ -101,7 +95,7 @@ do { \
i, (i) - one, (i) - one); \
} while (0)

-static __init void test_atomic(void)
+static void test_atomic(struct kunit *test)
{
int v0 = 0xaaa31337;
int v1 = 0xdeadbeef;
@@ -144,7 +138,7 @@ static __init void test_atomic(void)
}

#define INIT(c) do { atomic64_set(&v, c); r = c; } while (0)
-static __init void test_atomic64(void)
+static void test_atomic64(struct kunit *test)
{
long long v0 = 0xaaa31337c001d00dLL;
long long v1 = 0xdeadbeefdeafcafeLL;
@@ -156,12 +150,12 @@ static __init void test_atomic64(void)

atomic64_t v = ATOMIC64_INIT(v0);
long long r = v0;
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_EQ(test, v.counter, r);

atomic64_set(&v, v1);
r = v1;
- BUG_ON(v.counter != r);
- BUG_ON(atomic64_read(&v) != r);
+ KUNIT_ASSERT_EQ(test, v.counter, r);
+ KUNIT_ASSERT_EQ(test, atomic64_read(&v), r);

TEST(64, add, +=, onestwos);
TEST(64, add, +=, -one);
@@ -190,12 +184,12 @@ static __init void test_atomic64(void)
INIT(v0);
atomic64_inc(&v);
r += one;
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_EQ(test, v.counter, r);

INIT(v0);
atomic64_dec(&v);
r -= one;
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_EQ(test, v.counter, r);

INC_RETURN_FAMILY_TEST(64, v0);
DEC_RETURN_FAMILY_TEST(64, v0);
@@ -204,73 +198,76 @@ static __init void test_atomic64(void)
CMPXCHG_FAMILY_TEST(64, v0, v1, v2);

INIT(v0);
- BUG_ON(atomic64_add_unless(&v, one, v0));
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_FALSE(test, atomic64_add_unless(&v, one, v0));
+ KUNIT_ASSERT_EQ(test, v.counter, r);

INIT(v0);
- BUG_ON(!atomic64_add_unless(&v, one, v1));
+ KUNIT_ASSERT_TRUE(test, atomic64_add_unless(&v, one, v1));
r += one;
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_EQ(test, v.counter, r);

INIT(onestwos);
- BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
+ KUNIT_ASSERT_EQ(test, atomic64_dec_if_positive(&v), (onestwos - 1));
r -= one;
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_EQ(test, v.counter, r);

INIT(0);
- BUG_ON(atomic64_dec_if_positive(&v) != -one);
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_EQ(test, atomic64_dec_if_positive(&v), -one);
+ KUNIT_ASSERT_EQ(test, v.counter, r);

INIT(-one);
- BUG_ON(atomic64_dec_if_positive(&v) != (-one - one));
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_EQ(test, atomic64_dec_if_positive(&v), (-one - one));
+ KUNIT_ASSERT_EQ(test, v.counter, r);

INIT(onestwos);
- BUG_ON(!atomic64_inc_not_zero(&v));
+ KUNIT_ASSERT_TRUE(test, atomic64_inc_not_zero(&v));
r += one;
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_EQ(test, v.counter, r);

INIT(0);
- BUG_ON(atomic64_inc_not_zero(&v));
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_FALSE(test, atomic64_inc_not_zero(&v));
+ KUNIT_ASSERT_EQ(test, v.counter, r);

INIT(-one);
- BUG_ON(!atomic64_inc_not_zero(&v));
+ KUNIT_ASSERT_TRUE(test, atomic64_inc_not_zero(&v));
r += one;
- BUG_ON(v.counter != r);
+ KUNIT_ASSERT_EQ(test, v.counter, r);

/* Confirm the return value fits in an int, even if the value doesn't */
INIT(v3);
+
r_int = atomic64_inc_not_zero(&v);
- BUG_ON(!r_int);
+ KUNIT_ASSERT_NE(test, r_int, 0);
}

-static __init int test_atomics_init(void)
-{
- test_atomic();
- test_atomic64();
+static struct kunit_case atomic_test_cases[] = {
+ KUNIT_CASE(test_atomic),
+ KUNIT_CASE(test_atomic64),
+ {},
+};

+static void atomic_suite_exit(struct kunit_suite *suite)
+{
#ifdef CONFIG_X86
- pr_info("passed for %s platform %s CX8 and %s SSE\n",
+ kunit_info(suite, "ran on %s platform %s CX8 and %s SSE\n",
#ifdef CONFIG_X86_64
- "x86-64",
+ "x86-64",
#elif defined(CONFIG_X86_CMPXCHG64)
- "i586+",
+ "i586+",
#else
- "i386+",
+ "i386+",
#endif
- boot_cpu_has(X86_FEATURE_CX8) ? "with" : "without",
- boot_cpu_has(X86_FEATURE_XMM) ? "with" : "without");
-#else
- pr_info("passed\n");
+ boot_cpu_has(X86_FEATURE_CX8) ? "with" : "without",
+ boot_cpu_has(X86_FEATURE_XMM) ? "with" : "without");
#endif
-
- return 0;
}

-static __exit void test_atomics_exit(void) {}
+static struct kunit_suite atomic_test_suite = {
+ .name = "atomic",
+ .test_cases = atomic_test_cases,
+ .suite_exit = atomic_suite_exit,
+};

-module_init(test_atomics_init);
-module_exit(test_atomics_exit);
+kunit_test_suites(&atomic_test_suite);

MODULE_LICENSE("GPL");

base-commit: 38289a26e1b8a37755f3e07056ca416c1ee2a2e8
--
2.36.0.464.gb9c8b46e94-goog