[PATCH 11/17] locking/lockdep: Adjust lockdep selftest cases

Yuyang Du
2019-05-13T09:14:31Z

With read-write lock support, some read-write lock cases need to be updated,
specifically, some read-lock involved deadlocks are actually not deadlocks.
Hope I am not wildly wrong.

Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
lib/locking-selftest.c | 44 +++++++++++++++++++++++++++++++++-----------
1 file changed, 33 insertions(+), 11 deletions(-)

diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index a170554..f83f047 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -424,7 +424,7 @@ static void rwsem_ABBA2(void)
ML(Y1);
RSL(X1);
RSU(X1);
- MU(Y1); // should fail
+ MU(Y1); // should NOT fail
}

@@ -462,12 +462,13 @@ static void rwsem_ABBA3(void)

/*
* ABBA deadlock:
+ *
+ * Should fail except for either A or B is read lock.
*/
-
#define E() \
\
LOCK_UNLOCK_2(A, B); \
- LOCK_UNLOCK_2(B, A); /* fail */
+ LOCK_UNLOCK_2(B, A);

/*
* 6 testcases:
@@ -494,13 +495,15 @@ static void rwsem_ABBA3(void)

/*
* AB BC CA deadlock:
+ *
+ * Should fail except for read or recursive-read locks.
*/

#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(B, C); \
- LOCK_UNLOCK_2(C, A); /* fail */
+ LOCK_UNLOCK_2(C, A);

/*
* 6 testcases:
@@ -527,13 +530,15 @@ static void rwsem_ABBA3(void)

/*
* AB CA BC deadlock:
+ *
+ * Should fail except for read or recursive-read locks.
*/

#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(C, A); \
- LOCK_UNLOCK_2(B, C); /* fail */
+ LOCK_UNLOCK_2(B, C);

/*
* 6 testcases:
@@ -560,6 +565,8 @@ static void rwsem_ABBA3(void)

/*
* AB BC CD DA deadlock:
+ *
+ * Should fail except for read or recursive-read locks.
*/

#define E() \
@@ -567,7 +574,7 @@ static void rwsem_ABBA3(void)
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(B, C); \
LOCK_UNLOCK_2(C, D); \
- LOCK_UNLOCK_2(D, A); /* fail */
+ LOCK_UNLOCK_2(D, A);

/*
* 6 testcases:
@@ -594,13 +601,15 @@ static void rwsem_ABBA3(void)

/*
* AB CD BD DA deadlock:
+ *
+ * Should fail except for read or recursive-read locks.
*/
#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(C, D); \
LOCK_UNLOCK_2(B, D); \
- LOCK_UNLOCK_2(D, A); /* fail */
+ LOCK_UNLOCK_2(D, A);

/*
* 6 testcases:
@@ -627,13 +636,15 @@ static void rwsem_ABBA3(void)

/*
* AB CD BC DA deadlock:
+ *
+ * Should fail except for read or recursive-read locks.
*/
#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(C, D); \
LOCK_UNLOCK_2(B, C); \
- LOCK_UNLOCK_2(D, A); /* fail */
+ LOCK_UNLOCK_2(D, A);

/*
* 6 testcases:
@@ -1238,7 +1249,7 @@ static inline void print_testname(const char *testname)
/*
* 'read' variant: rlocks must not trigger.
*/
-#define DO_TESTCASE_6R(desc, name) \
+#define DO_TESTCASE_6AA(desc, name) \
print_testname(desc); \
dotest(name##_spin, FAILURE, LOCKTYPE_SPIN); \
dotest(name##_wlock, FAILURE, LOCKTYPE_RWLOCK); \
@@ -1249,6 +1260,17 @@ static inline void print_testname(const char *testname)
dotest_rt(name##_rtmutex, FAILURE, LOCKTYPE_RTMUTEX); \
pr_cont("\n");

+#define DO_TESTCASE_6R(desc, name) \
+ print_testname(desc); \
+ dotest(name##_spin, FAILURE, LOCKTYPE_SPIN); \
+ dotest(name##_wlock, FAILURE, LOCKTYPE_RWLOCK); \
+ dotest(name##_rlock, SUCCESS, LOCKTYPE_RWLOCK); \
+ dotest(name##_mutex, FAILURE, LOCKTYPE_MUTEX); \
+ dotest(name##_wsem, FAILURE, LOCKTYPE_RWSEM); \
+ dotest(name##_rsem, SUCCESS, LOCKTYPE_RWSEM); \
+ dotest_rt(name##_rtmutex, FAILURE, LOCKTYPE_RTMUTEX); \
+ pr_cont("\n");
+
#define DO_TESTCASE_2I(desc, name, nr) \
DO_TESTCASE_1("hard-"desc, name##_hard, nr); \
DO_TESTCASE_1("soft-"desc, name##_soft, nr);
@@ -1991,7 +2013,7 @@ void locking_selftest(void)
debug_locks_silent = !debug_locks_verbose;
lockdep_set_selftest_task(current);

- DO_TESTCASE_6R("A-A deadlock", AA);
+ DO_TESTCASE_6AA("A-A deadlock", AA);
DO_TESTCASE_6R("A-B-B-A deadlock", ABBA);
DO_TESTCASE_6R("A-B-B-C-C-A deadlock", ABBCCA);
DO_TESTCASE_6R("A-B-C-A-B-C deadlock", ABCABC);
@@ -2048,7 +2070,7 @@ void locking_selftest(void)
pr_cont(" |");
dotest(rlock_ABBA2, SUCCESS, LOCKTYPE_RWLOCK);
pr_cont(" |");
- dotest(rwsem_ABBA2, FAILURE, LOCKTYPE_RWSEM);
+ dotest(rwsem_ABBA2, SUCCESS, LOCKTYPE_RWSEM);

print_testname("mixed write-lock/lock-write ABBA");
pr_cont(" |");
--
1.8.3.1