From c22fb3807fd0a3bdd98c13c4d2190ab064e6c09d Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 1 Dec 2016 11:47:07 +0000 Subject: locking/ww_mutex: Add kselftests for ww_mutex AA deadlock detection Signed-off-by: Chris Wilson Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Maarten Lankhorst Cc: Nicolai Hähnle Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20161201114711.28697-5-chris@chris-wilson.co.uk Signed-off-by: Ingo Molnar --- kernel/locking/test-ww_mutex.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'kernel/locking') diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c index 472d5b1f303f..835fa7a1036e 100644 --- a/kernel/locking/test-ww_mutex.c +++ b/kernel/locking/test-ww_mutex.c @@ -118,6 +118,41 @@ static int test_mutex(void) return 0; } +static int test_aa(void) +{ + struct ww_mutex mutex; + struct ww_acquire_ctx ctx; + int ret; + + ww_mutex_init(&mutex, &ww_class); + ww_acquire_init(&ctx, &ww_class); + + ww_mutex_lock(&mutex, &ctx); + + if (ww_mutex_trylock(&mutex)) { + pr_err("%s: trylocked itself!\n", __func__); + ww_mutex_unlock(&mutex); + ret = -EINVAL; + goto out; + } + + ret = ww_mutex_lock(&mutex, &ctx); + if (ret != -EALREADY) { + pr_err("%s: missed deadlock for recursing, ret=%d\n", + __func__, ret); + if (!ret) + ww_mutex_unlock(&mutex); + ret = -EINVAL; + goto out; + } + + ret = 0; +out: + ww_mutex_unlock(&mutex); + ww_acquire_fini(&ctx); + return ret; +} + static int __init test_ww_mutex_init(void) { int ret; @@ -126,6 +161,10 @@ static int __init test_ww_mutex_init(void) if (ret) return ret; + ret = test_aa(); + if (ret) + return ret; + return 0; } -- cgit v1.2.3