[RFC lockdep 4/4] lockdep/selftest: Add wait context selftests
From: Boqun Feng
Date: Tue Dec 08 2020 - 05:33:43 EST
These tests are added for two purposes:
* Test the implementation of wait context checks and related
annotations.
* Semi-document the rules for wait context nesting when
PROVE_RAW_LOCK_NESTING=y.
The test cases are only avaible for PROVE_RAW_LOCK_NESTING=y, as wait
context checking makes more sense for that configuration.
Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx>
---
lib/locking-selftest.c | 232 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 232 insertions(+)
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 0af91a07fd18..c00ef4e69637 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -63,6 +63,9 @@ static DEFINE_SPINLOCK(lock_B);
static DEFINE_SPINLOCK(lock_C);
static DEFINE_SPINLOCK(lock_D);
+static DEFINE_RAW_SPINLOCK(raw_lock_A);
+static DEFINE_RAW_SPINLOCK(raw_lock_B);
+
static DEFINE_RWLOCK(rwlock_A);
static DEFINE_RWLOCK(rwlock_B);
static DEFINE_RWLOCK(rwlock_C);
@@ -1306,6 +1309,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock)
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define I_SPINLOCK(x) lockdep_reset_lock(&lock_##x.dep_map)
+# define I_RAW_SPINLOCK(x) lockdep_reset_lock(&raw_lock_##x.dep_map)
# define I_RWLOCK(x) lockdep_reset_lock(&rwlock_##x.dep_map)
# define I_MUTEX(x) lockdep_reset_lock(&mutex_##x.dep_map)
# define I_RWSEM(x) lockdep_reset_lock(&rwsem_##x.dep_map)
@@ -1315,6 +1319,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock)
#endif
#else
# define I_SPINLOCK(x)
+# define I_RAW_SPINLOCK(x)
# define I_RWLOCK(x)
# define I_MUTEX(x)
# define I_RWSEM(x)
@@ -1358,9 +1363,12 @@ static void reset_locks(void)
I1(A); I1(B); I1(C); I1(D);
I1(X1); I1(X2); I1(Y1); I1(Y2); I1(Z1); I1(Z2);
I_WW(t); I_WW(t2); I_WW(o.base); I_WW(o2.base); I_WW(o3.base);
+ I_RAW_SPINLOCK(A); I_RAW_SPINLOCK(B);
lockdep_reset();
I2(A); I2(B); I2(C); I2(D);
init_shared_classes();
+ raw_spin_lock_init(&raw_lock_A);
+ raw_spin_lock_init(&raw_lock_B);
ww_mutex_init(&o, &ww_lockdep); ww_mutex_init(&o2, &ww_lockdep); ww_mutex_init(&o3, &ww_lockdep);
memset(&t, 0, sizeof(t)); memset(&t2, 0, sizeof(t2));
@@ -2358,6 +2366,226 @@ static void queued_read_lock_tests(void)
pr_cont("\n");
}
+#define __guard(cleanup) __maybe_unused __attribute__((__cleanup__(cleanup)))
+
+static void hardirq_exit(int *_)
+{
+ HARDIRQ_EXIT();
+}
+
+#define HARDIRQ_CONTEXT(name, ...) \
+ int hardirq_guard_##name __guard(hardirq_exit); \
+ HARDIRQ_ENTER();
+
+#define NOTTHREADED_HARDIRQ_CONTEXT(name, ...) \
+ int notthreaded_hardirq_guard_##name __guard(hardirq_exit); \
+ local_irq_disable(); \
+ __irq_enter(); \
+ WARN_ON(!in_irq());
+
+static void softirq_exit(int *_)
+{
+ SOFTIRQ_EXIT();
+}
+
+#define SOFTIRQ_CONTEXT(name, ...) \
+ int softirq_guard_##name __guard(softirq_exit); \
+ SOFTIRQ_ENTER();
+
+static void rcu_exit(int *_)
+{
+ rcu_read_unlock();
+}
+
+#define RCU_CONTEXT(name, ...) \
+ int rcu_guard_##name __guard(rcu_exit); \
+ rcu_read_lock();
+
+static void rcu_bh_exit(int *_)
+{
+ rcu_read_unlock_bh();
+}
+
+#define RCU_BH_CONTEXT(name, ...) \
+ int rcu_bh_guard_##name __guard(rcu_bh_exit); \
+ rcu_read_lock_bh();
+
+static void rcu_sched_exit(int *_)
+{
+ rcu_read_unlock_sched();
+}
+
+#define RCU_SCHED_CONTEXT(name, ...) \
+ int rcu_sched_guard_##name __guard(rcu_sched_exit); \
+ rcu_read_lock_sched();
+
+static void rcu_callback_exit(int *_)
+{
+ rcu_lock_release(&rcu_callback_map);
+}
+
+#define RCU_CALLBACK_CONTEXT(name, ...) \
+ int rcu_callback_guard_##name __guard(rcu_callback_exit); \
+ rcu_lock_acquire(&rcu_callback_map);
+
+
+static void raw_spinlock_exit(raw_spinlock_t **lock)
+{
+ raw_spin_unlock(*lock);
+}
+
+#define RAW_SPINLOCK_CONTEXT(name, lock) \
+ raw_spinlock_t *raw_spinlock_guard_##name __guard(raw_spinlock_exit) = &(lock); \
+ raw_spin_lock(&(lock));
+
+static void spinlock_exit(spinlock_t **lock)
+{
+ spin_unlock(*lock);
+}
+
+#define SPINLOCK_CONTEXT(name, lock) \
+ spinlock_t *spinlock_guard_##name __guard(spinlock_exit) = &(lock); \
+ spin_lock(&(lock));
+
+static void mutex_exit(struct mutex **lock)
+{
+ mutex_unlock(*lock);
+}
+
+#define MUTEX_CONTEXT(name, lock) \
+ struct mutex *mutex_guard_##name __guard(mutex_exit) = &(lock); \
+ mutex_lock(&(lock));
+
+#define GENERATE_2_CONTEXT_TESTCASE(outer, outer_lock, inner, inner_lock) \
+ \
+static void __maybe_unused inner##_in_##outer(void) \
+{ \
+ outer##_CONTEXT(_, outer_lock); \
+ { \
+ inner##_CONTEXT(_, inner_lock); \
+ } \
+}
+
+/*
+ * wait contexts (considering PREEMPT_RT)
+ *
+ * o: inner is allowed in outer
+ * x: inner is disallowed in outer
+ *
+ * \ inner | RCU | RAW_SPIN | SPIN | MUTEX
+ * outer \ | | | |
+ * ---------------+-------+----------+------+-------
+ * HARDIRQ | o | o | o | x
+ * ---------------+-------+----------+------+-------
+ * NOTTHREADED_IRQ| o | o | x | x
+ * ---------------+-------+----------+------+-------
+ * SOFTIRQ | o | o | o | x
+ * ---------------+-------+----------+------+-------
+ * RCU | o | o | o | x
+ * ---------------+-------+----------+------+-------
+ * RCU_BH | o | o | o | x
+ * ---------------+-------+----------+------+-------
+ * RCU_CALLBACK | o | o | o | x
+ * ---------------+-------+----------+------+-------
+ * RCU_SCHED | o | o | x | x
+ * ---------------+-------+----------+------+-------
+ * RAW_SPIN | o | o | x | x
+ * ---------------+-------+----------+------+-------
+ * SPIN | o | o | o | x
+ * ---------------+-------+----------+------+-------
+ * MUTEX | o | o | o | o
+ * ---------------+-------+----------+------+-------
+ */
+
+#define GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(HARDIRQ, , inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(NOTTHREADED_HARDIRQ, , inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(SOFTIRQ, , inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(RCU, , inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(RCU_BH, , inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(RCU_CALLBACK, , inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(RCU_SCHED, , inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(RAW_SPINLOCK, raw_lock_A, inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(SPINLOCK, lock_A, inner, inner_lock) \
+GENERATE_2_CONTEXT_TESTCASE(MUTEX, mutex_A, inner, inner_lock)
+
+GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(RCU, )
+GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(RAW_SPINLOCK, raw_lock_B)
+GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(SPINLOCK, lock_B)
+GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(MUTEX, mutex_B)
+
+/* the outer context allows all kinds of preemption */
+#define DO_CONTEXT_TESTCASE_OUTER_PREEMPTIBLE(outer) \
+ dotest(RCU_in_##outer, SUCCESS, LOCKTYPE_RWLOCK); \
+ dotest(RAW_SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \
+ dotest(SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \
+ dotest(MUTEX_in_##outer, SUCCESS, LOCKTYPE_MUTEX); \
+
+/*
+ * the outer context only allows the preemption introduced by spinlock_t (which
+ * is a sleepable lock for PREEMPT_RT)
+ */
+#define DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(outer) \
+ dotest(RCU_in_##outer, SUCCESS, LOCKTYPE_RWLOCK); \
+ dotest(RAW_SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \
+ dotest(SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \
+ dotest(MUTEX_in_##outer, FAILURE, LOCKTYPE_MUTEX); \
+
+/* the outer doesn't allows any kind of preemption */
+#define DO_CONTEXT_TESTCASE_OUTER_NOT_PREEMPTIBLE(outer) \
+ dotest(RCU_in_##outer, SUCCESS, LOCKTYPE_RWLOCK); \
+ dotest(RAW_SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \
+ dotest(SPINLOCK_in_##outer, FAILURE, LOCKTYPE_SPIN); \
+ dotest(MUTEX_in_##outer, FAILURE, LOCKTYPE_MUTEX); \
+
+static void wait_context_tests(void)
+{
+ printk(" --------------------------------------------------------------------------\n");
+ printk(" | wait context tests |\n");
+ printk(" --------------------------------------------------------------------------\n");
+ printk(" | rcu | raw | spin |mutex |\n");
+ printk(" --------------------------------------------------------------------------\n");
+ print_testname("in hardirq context");
+ DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(HARDIRQ);
+ pr_cont("\n");
+
+ print_testname("in hardirq context (not threaded)");
+ DO_CONTEXT_TESTCASE_OUTER_NOT_PREEMPTIBLE(NOTTHREADED_HARDIRQ);
+ pr_cont("\n");
+
+ print_testname("in softirq context");
+ DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(SOFTIRQ);
+ pr_cont("\n");
+
+ print_testname("in RCU context");
+ DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(RCU);
+ pr_cont("\n");
+
+ print_testname("in RCU-bh context");
+ DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(RCU_BH);
+ pr_cont("\n");
+
+ print_testname("in RCU callback context");
+ DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(RCU_CALLBACK);
+ pr_cont("\n");
+
+ print_testname("in RCU-sched context");
+ DO_CONTEXT_TESTCASE_OUTER_NOT_PREEMPTIBLE(RCU_SCHED);
+ pr_cont("\n");
+
+ print_testname("in RAW_SPINLOCK context");
+ DO_CONTEXT_TESTCASE_OUTER_NOT_PREEMPTIBLE(RAW_SPINLOCK);
+ pr_cont("\n");
+
+ print_testname("in SPINLOCK context");
+ DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(SPINLOCK);
+ pr_cont("\n");
+
+ print_testname("in MUTEX context");
+ DO_CONTEXT_TESTCASE_OUTER_PREEMPTIBLE(MUTEX);
+ pr_cont("\n");
+}
+
void locking_selftest(void)
{
/*
@@ -2479,6 +2707,10 @@ void locking_selftest(void)
if (IS_ENABLED(CONFIG_QUEUED_RWLOCKS))
queued_read_lock_tests();
+ /* Wait context test cases that are specific for RAW_LOCK_NESTING */
+ if (IS_ENABLED(CONFIG_PROVE_RAW_LOCK_NESTING))
+ wait_context_tests();
+
if (unexpected_testcase_failures) {
printk("-----------------------------------------------------------------\n");
debug_locks = 0;
--
2.29.2