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authorAlfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com>2016-02-19 07:48:52 +0100
committerIngo Molnar <mingo@kernel.org>2016-02-29 10:29:33 +0100
commit11a1ac206d0806b0db39712c3292f6006e77a7e8 (patch)
treeadc555ad39ed6c14312b6d0342a53d6145cf4a45 /tools
parenttools/lib/lockdep: Add userspace version of READ_ONCE() (diff)
downloadlinux-11a1ac206d0806b0db39712c3292f6006e77a7e8.tar.xz
linux-11a1ac206d0806b0db39712c3292f6006e77a7e8.zip
tools/lib/lockdep: Add tests for AA and ABBA locking
Add test for AA and 2 threaded ABBA locking. Rename AA.c to ABA.c since it was implementing an ABA instead of a pure AA. Now both cases are covered. The expected output for AA.c is that the process blocks and lockdep reports a deadlock. ABBA_2threads.c differs from ABBA.c in that lockdep keeps separate chains of held locks per task. This can lead to different behaviour regarding lock detection. The expected output for this test is that the process blocks and lockdep reports a circular locking dependency. These tests found a lockdep bug - fixed by the next commit. Signed-off-by: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1455864533-7536-3-git-send-email-alfredoalvarezernandez@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools')
-rw-r--r--tools/lib/lockdep/tests/AA.c8
-rw-r--r--tools/lib/lockdep/tests/ABA.c13
-rw-r--r--tools/lib/lockdep/tests/ABBA_2threads.c46
3 files changed, 63 insertions, 4 deletions
diff --git a/tools/lib/lockdep/tests/AA.c b/tools/lib/lockdep/tests/AA.c
index 0f782ff404ac..18211a5f354f 100644
--- a/tools/lib/lockdep/tests/AA.c
+++ b/tools/lib/lockdep/tests/AA.c
@@ -1,13 +1,13 @@
#include <liblockdep/mutex.h>
-void main(void)
+int main(void)
{
- pthread_mutex_t a, b;
+ pthread_mutex_t a;
pthread_mutex_init(&a, NULL);
- pthread_mutex_init(&b, NULL);
pthread_mutex_lock(&a);
- pthread_mutex_lock(&b);
pthread_mutex_lock(&a);
+
+ return 0;
}
diff --git a/tools/lib/lockdep/tests/ABA.c b/tools/lib/lockdep/tests/ABA.c
new file mode 100644
index 000000000000..0f782ff404ac
--- /dev/null
+++ b/tools/lib/lockdep/tests/ABA.c
@@ -0,0 +1,13 @@
+#include <liblockdep/mutex.h>
+
+void main(void)
+{
+ pthread_mutex_t a, b;
+
+ pthread_mutex_init(&a, NULL);
+ pthread_mutex_init(&b, NULL);
+
+ pthread_mutex_lock(&a);
+ pthread_mutex_lock(&b);
+ pthread_mutex_lock(&a);
+}
diff --git a/tools/lib/lockdep/tests/ABBA_2threads.c b/tools/lib/lockdep/tests/ABBA_2threads.c
new file mode 100644
index 000000000000..cd807d736361
--- /dev/null
+++ b/tools/lib/lockdep/tests/ABBA_2threads.c
@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <pthread.h>
+
+pthread_mutex_t a = PTHREAD_MUTEX_INITIALIZER;
+pthread_mutex_t b = PTHREAD_MUTEX_INITIALIZER;
+pthread_barrier_t bar;
+
+void *ba_lock(void *arg)
+{
+ int ret, i;
+
+ pthread_mutex_lock(&b);
+
+ if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD)
+ pthread_barrier_destroy(&bar);
+
+ pthread_mutex_lock(&a);
+
+ pthread_mutex_unlock(&a);
+ pthread_mutex_unlock(&b);
+}
+
+int main(void)
+{
+ pthread_t t;
+
+ pthread_barrier_init(&bar, NULL, 2);
+
+ if (pthread_create(&t, NULL, ba_lock, NULL)) {
+ fprintf(stderr, "pthread_create() failed\n");
+ return 1;
+ }
+ pthread_mutex_lock(&a);
+
+ if (pthread_barrier_wait(&bar) == PTHREAD_BARRIER_SERIAL_THREAD)
+ pthread_barrier_destroy(&bar);
+
+ pthread_mutex_lock(&b);
+
+ pthread_mutex_unlock(&b);
+ pthread_mutex_unlock(&a);
+
+ pthread_join(t, NULL);
+
+ return 0;
+}