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Message-Id: <20161201114711.28697-5-chris@chris-wilson.co.uk>
Date: Thu, 1 Dec 2016 11:47:07 +0000
From: Chris Wilson <chris@...is-wilson.co.uk>
To: linux-kernel@...r.kernel.org
Cc: Chris Wilson <chris@...is-wilson.co.uk>,
Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>,
Maarten Lankhorst <dev@...ankhorst.nl>,
Nicolai Hähnle <nhaehnle@...il.com>
Subject: [PATCH v2 4/8] locking: Add kselftests for ww_mutex AA deadlock detection
Signed-off-by: Chris Wilson <chris@...is-wilson.co.uk>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Maarten Lankhorst <dev@...ankhorst.nl>
Cc: Nicolai Hähnle <nhaehnle@...il.com>
---
kernel/locking/test-ww_mutex.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
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;
}
--
2.10.2
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