Implement CONFIG_DEPT_UNIT_TEST introducing a kernel module that runs basic unit test for dept.
Signed-off-by: Byungchul Park byungchul@sk.com --- include/linux/dept_unit_test.h | 67 +++++++++++ kernel/dependency/Makefile | 1 + kernel/dependency/dept.c | 12 ++ kernel/dependency/dept_unit_test.c | 173 +++++++++++++++++++++++++++++ lib/Kconfig.debug | 12 ++ 5 files changed, 265 insertions(+) create mode 100644 include/linux/dept_unit_test.h create mode 100644 kernel/dependency/dept_unit_test.c
diff --git a/include/linux/dept_unit_test.h b/include/linux/dept_unit_test.h new file mode 100644 index 000000000000..7612b4e97e69 --- /dev/null +++ b/include/linux/dept_unit_test.h @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * DEPT unit test + * + * Started by Byungchul Park max.byungchul.park@gmail.com: + * + * Copyright (c) 2025 SK hynix, Inc., Byungchul Park + */ + +#ifndef __LINUX_DEPT_UNIT_TEST_H +#define __LINUX_DEPT_UNIT_TEST_H + +#if defined(CONFIG_DEPT_UNIT_TEST) || defined(CONFIG_DEPT_UNIT_TEST_MODULE) +struct dept_ut { + bool circle_detected; + bool recover_circle_detected; + + int ecxt_stack_total_cnt; + int wait_stack_total_cnt; + int evnt_stack_total_cnt; + int ecxt_stack_valid_cnt; + int wait_stack_valid_cnt; + int evnt_stack_valid_cnt; +}; + +extern struct dept_ut dept_ut_results; + +static inline void dept_ut_circle_detect(void) +{ + dept_ut_results.circle_detected = true; +} +static inline void dept_ut_recover_circle_detect(void) +{ + dept_ut_results.recover_circle_detected = true; +} +static inline void dept_ut_ecxt_stack_account(bool valid) +{ + dept_ut_results.ecxt_stack_total_cnt++; + + if (valid) + dept_ut_results.ecxt_stack_valid_cnt++; +} +static inline void dept_ut_wait_stack_account(bool valid) +{ + dept_ut_results.wait_stack_total_cnt++; + + if (valid) + dept_ut_results.wait_stack_valid_cnt++; +} +static inline void dept_ut_evnt_stack_account(bool valid) +{ + dept_ut_results.evnt_stack_total_cnt++; + + if (valid) + dept_ut_results.evnt_stack_valid_cnt++; +} +#else +struct dept_ut {}; + +#define dept_ut_circle_detect() do { } while (0) +#define dept_ut_recover_circle_detect() do { } while (0) +#define dept_ut_ecxt_stack_account(v) do { } while (0) +#define dept_ut_wait_stack_account(v) do { } while (0) +#define dept_ut_evnt_stack_account(v) do { } while (0) + +#endif +#endif /* __LINUX_DEPT_UNIT_TEST_H */ diff --git a/kernel/dependency/Makefile b/kernel/dependency/Makefile index 92f165400187..fc584ca87124 100644 --- a/kernel/dependency/Makefile +++ b/kernel/dependency/Makefile @@ -2,3 +2,4 @@
obj-$(CONFIG_DEPT) += dept.o obj-$(CONFIG_DEPT) += dept_proc.o +obj-$(CONFIG_DEPT_UNIT_TEST) += dept_unit_test.o diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c index 3c3ec2701bd6..0f4464657288 100644 --- a/kernel/dependency/dept.c +++ b/kernel/dependency/dept.c @@ -78,8 +78,12 @@ #include <linux/workqueue.h> #include <linux/irq_work.h> #include <linux/vmalloc.h> +#include <linux/dept_unit_test.h> #include "dept_internal.h"
+struct dept_ut dept_ut_results; +EXPORT_SYMBOL_GPL(dept_ut_results); + static int dept_stop; static int dept_per_cpu_ready;
@@ -826,6 +830,10 @@ static void print_dep(struct dept_dep *d) pr_warn("(wait to wake up)\n"); print_ip_stack(0, e->ewait_stack); } + + dept_ut_ecxt_stack_account(valid_stack(e->ecxt_stack)); + dept_ut_wait_stack_account(valid_stack(w->wait_stack)); + dept_ut_evnt_stack_account(valid_stack(e->event_stack)); } }
@@ -920,6 +928,8 @@ static void print_circle(struct dept_class *c) dump_stack();
dept_outworld_exit(); + + dept_ut_circle_detect(); }
/* @@ -1021,6 +1031,8 @@ static void print_recover_circle(struct dept_event_site *es) dump_stack();
dept_outworld_exit(); + + dept_ut_recover_circle_detect(); }
static void bfs_init_recover(void *node, void *in, void **out) diff --git a/kernel/dependency/dept_unit_test.c b/kernel/dependency/dept_unit_test.c new file mode 100644 index 000000000000..88e846b9f876 --- /dev/null +++ b/kernel/dependency/dept_unit_test.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * DEPT unit test + * + * Started by Byungchul Park max.byungchul.park@gmail.com: + * + * Copyright (c) 2025 SK hynix, Inc., Byungchul Park + */ + +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/dept.h> +#include <linux/dept_unit_test.h> + +MODULE_DESCRIPTION("DEPT unit test"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Byungchul Park max.byungchul.park@sk.com"); + +struct unit { + const char *name; + bool (*func)(void); + bool result; +}; + +static DEFINE_SPINLOCK(s1); +static DEFINE_SPINLOCK(s2); +static bool test_spin_lock_deadlock(void) +{ + dept_ut_results.circle_detected = false; + + spin_lock(&s1); + spin_lock(&s2); + spin_unlock(&s2); + spin_unlock(&s1); + + spin_lock(&s2); + spin_lock(&s1); + spin_unlock(&s1); + spin_unlock(&s2); + + return dept_ut_results.circle_detected; +} + +static DEFINE_MUTEX(m1); +static DEFINE_MUTEX(m2); +static bool test_mutex_lock_deadlock(void) +{ + dept_ut_results.circle_detected = false; + + mutex_lock(&m1); + mutex_lock(&m2); + mutex_unlock(&m2); + mutex_unlock(&m1); + + mutex_lock(&m2); + mutex_lock(&m1); + mutex_unlock(&m1); + mutex_unlock(&m2); + + return dept_ut_results.circle_detected; +} + +static bool test_wait_event_deadlock(void) +{ + struct dept_map dmap1; + struct dept_map dmap2; + + sdt_map_init(&dmap1); + sdt_map_init(&dmap2); + + dept_ut_results.circle_detected = false; + + sdt_request_event(&dmap1); /* [S] */ + sdt_wait(&dmap2); /* [W] */ + sdt_event(&dmap1); /* [E] */ + + sdt_request_event(&dmap2); /* [S] */ + sdt_wait(&dmap1); /* [W] */ + sdt_event(&dmap2); /* [E] */ + + return dept_ut_results.circle_detected; +} + +static void dummy_event(void) +{ + /* Do nothing. */ +} + +static DEFINE_DEPT_EVENT_SITE(es1); +static DEFINE_DEPT_EVENT_SITE(es2); +static bool test_recover_deadlock(void) +{ + dept_ut_results.recover_circle_detected = false; + + dept_recover_event(&es1, &es2); + dept_recover_event(&es2, &es1); + + event_site(&es1, dummy_event); + event_site(&es2, dummy_event); + + return dept_ut_results.recover_circle_detected; +} + +static struct unit units[] = { + { + .name = "spin lock deadlock test", + .func = test_spin_lock_deadlock, + }, + { + .name = "mutex lock deadlock test", + .func = test_mutex_lock_deadlock, + }, + { + .name = "wait event deadlock test", + .func = test_wait_event_deadlock, + }, + { + .name = "event recover deadlock test", + .func = test_recover_deadlock, + }, +}; + +static int __init dept_ut_init(void) +{ + int i; + + lockdep_off(); + + dept_ut_results.ecxt_stack_valid_cnt = 0; + dept_ut_results.ecxt_stack_total_cnt = 0; + dept_ut_results.wait_stack_valid_cnt = 0; + dept_ut_results.wait_stack_total_cnt = 0; + dept_ut_results.evnt_stack_valid_cnt = 0; + dept_ut_results.evnt_stack_total_cnt = 0; + + for (i = 0; i < ARRAY_SIZE(units); i++) + units[i].result = units[i].func(); + + pr_info("\n"); + pr_info("******************************************\n"); + pr_info("DEPT unit test results\n"); + pr_info("******************************************\n"); + for (i = 0; i < ARRAY_SIZE(units); i++) { + pr_info("(%s) %s\n", units[i].result ? "pass" : "fail", + units[i].name); + } + pr_info("ecxt stack valid count = %d/%d\n", + dept_ut_results.ecxt_stack_valid_cnt, + dept_ut_results.ecxt_stack_total_cnt); + pr_info("wait stack valid count = %d/%d\n", + dept_ut_results.wait_stack_valid_cnt, + dept_ut_results.wait_stack_total_cnt); + pr_info("event stack valid count = %d/%d\n", + dept_ut_results.evnt_stack_valid_cnt, + dept_ut_results.evnt_stack_total_cnt); + pr_info("******************************************\n"); + pr_info("\n"); + + lockdep_on(); + + return 0; +} + +static void dept_ut_cleanup(void) +{ + /* + * Do nothing for now. + */ +} + +module_init(dept_ut_init); +module_exit(dept_ut_cleanup); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 540583425d8e..86e26b9708fa 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1404,6 +1404,18 @@ config DEPT_AGGRESSIVE_TIMEOUT_WAIT that timeout is used to avoid a deadlock. Say N if you'd like to avoid verbose reports.
+config DEPT_UNIT_TEST + tristate "unit test for DEPT" + depends on DEBUG_KERNEL && DEPT + default n + help + This option provides a kernel module that runs unit test for + DEPT. + + Say Y if you want DEPT unit test to be built into the kernel. + Say M if you want DEPT unit test to build as a module. + Say N if you are unsure. + config LOCK_DEBUGGING_SUPPORT bool depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT