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| author | Peter Zijlstra <peterz@infradead.org> | 2017-08-23 13:13:11 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-25 11:06:31 +0200 |
| commit | e91498589746065e3ae95d9a00b068e525eec34f (patch) | |
| tree | 9b7d6663dbfce16abc8cb6228c56dd72e4fff83c /lib/locking-selftest.c | |
| parent | mm, locking/barriers: Clarify tlb_flush_pending() barriers (diff) | |
| download | linux-e91498589746065e3ae95d9a00b068e525eec34f.tar.xz linux-e91498589746065e3ae95d9a00b068e525eec34f.zip | |
locking/lockdep/selftests: Add mixed read-write ABBA tests
Currently lockdep has limited support for recursive readers, add a few
mixed read-write ABBA selftests to show the extend of these
limitations.
[ 0.000000] ----------------------------------------------------------------------------
[ 0.000000] | spin |wlock |rlock |mutex | wsem | rsem |
[ 0.000000] --------------------------------------------------------------------------
[ 0.000000] mixed read-lock/lock-write ABBA: |FAILED| | ok |
[ 0.000000] mixed read-lock/lock-read ABBA: | ok | | ok |
[ 0.000000] mixed write-lock/lock-write ABBA: | ok | | ok |
This clearly illustrates the case where lockdep fails to find a
deadlock.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boqun.feng@gmail.com
Cc: byungchul.park@lge.com
Cc: david@fromorbit.com
Cc: johannes@sipsolutions.net
Cc: oleg@redhat.com
Cc: tj@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib/locking-selftest.c')
| -rw-r--r-- | lib/locking-selftest.c | 117 |
1 files changed, 115 insertions, 2 deletions
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 6f2b135dc5e8..3c7151a6cd98 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -363,6 +363,103 @@ static void rsem_AA3(void) } /* + * read_lock(A) + * spin_lock(B) + * spin_lock(B) + * write_lock(A) + */ +static void rlock_ABBA1(void) +{ + RL(X1); + L(Y1); + U(Y1); + RU(X1); + + L(Y1); + WL(X1); + WU(X1); + U(Y1); // should fail +} + +static void rwsem_ABBA1(void) +{ + RSL(X1); + ML(Y1); + MU(Y1); + RSU(X1); + + ML(Y1); + WSL(X1); + WSU(X1); + MU(Y1); // should fail +} + +/* + * read_lock(A) + * spin_lock(B) + * spin_lock(B) + * read_lock(A) + */ +static void rlock_ABBA2(void) +{ + RL(X1); + L(Y1); + U(Y1); + RU(X1); + + L(Y1); + RL(X1); + RU(X1); + U(Y1); // should NOT fail +} + +static void rwsem_ABBA2(void) +{ + RSL(X1); + ML(Y1); + MU(Y1); + RSU(X1); + + ML(Y1); + RSL(X1); + RSU(X1); + MU(Y1); // should fail +} + + +/* + * write_lock(A) + * spin_lock(B) + * spin_lock(B) + * write_lock(A) + */ +static void rlock_ABBA3(void) +{ + WL(X1); + L(Y1); + U(Y1); + WU(X1); + + L(Y1); + WL(X1); + WU(X1); + U(Y1); // should fail +} + +static void rwsem_ABBA3(void) +{ + WSL(X1); + ML(Y1); + MU(Y1); + WSU(X1); + + ML(Y1); + WSL(X1); + WSU(X1); + MU(Y1); // should fail +} + +/* * ABBA deadlock: */ @@ -1056,8 +1153,6 @@ static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask) if (debug_locks != expected) { unexpected_testcase_failures++; pr_cont("FAILED|"); - - dump_stack(); } else { testcase_successes++; pr_cont(" ok |"); @@ -1933,6 +2028,24 @@ void locking_selftest(void) dotest(rsem_AA3, FAILURE, LOCKTYPE_RWSEM); pr_cont("\n"); + print_testname("mixed read-lock/lock-write ABBA"); + pr_cont(" |"); + dotest(rlock_ABBA1, FAILURE, LOCKTYPE_RWLOCK); + pr_cont(" |"); + dotest(rwsem_ABBA1, FAILURE, LOCKTYPE_RWSEM); + + print_testname("mixed read-lock/lock-read ABBA"); + pr_cont(" |"); + dotest(rlock_ABBA2, SUCCESS, LOCKTYPE_RWLOCK); + pr_cont(" |"); + dotest(rwsem_ABBA2, FAILURE, LOCKTYPE_RWSEM); + + print_testname("mixed write-lock/lock-write ABBA"); + pr_cont(" |"); + dotest(rlock_ABBA3, FAILURE, LOCKTYPE_RWLOCK); + pr_cont(" |"); + dotest(rwsem_ABBA3, FAILURE, LOCKTYPE_RWSEM); + printk(" --------------------------------------------------------------------------\n"); /* |