[PATCH] lockdep: locking API self tests

Introduce DEBUG_LOCKING_API_SELFTESTS, which uses the generic lock debugging
code's silent-failure feature to run a matrix of testcases.  There are 210
testcases currently:

  +-----------------------
  | Locking API testsuite:
  +------------------------------+------+------+------+------+------+------+
                                 | spin |wlock |rlock |mutex | wsem | rsem |
  -------------------------------+------+------+------+------+------+------+
                     A-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
                 A-B-B-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
             A-B-B-C-C-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
             A-B-C-A-B-C deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
         A-B-B-C-C-D-D-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
         A-B-C-D-B-D-D-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
         A-B-C-D-B-C-D-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
                    double unlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
                 bad unlock order:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |
  --------------------------------------+------+------+------+------+------+
              recursive read-lock:             |  ok  |             |  ok  |
  --------------------------------------+------+------+------+------+------+
                non-nested unlock:  ok  |  ok  |  ok  |  ok  |
  --------------------------------------+------+------+------+
     hard-irqs-on + irq-safe-A/12:  ok  |  ok  |  ok  |
     soft-irqs-on + irq-safe-A/12:  ok  |  ok  |  ok  |
     hard-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
     soft-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
       sirq-safe-A => hirqs-on/12:  ok  |  ok  |  ok  |
       sirq-safe-A => hirqs-on/21:  ok  |  ok  |  ok  |
         hard-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
         soft-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
         hard-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
         soft-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #1/132:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #1/132:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #1/213:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #1/213:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #1/231:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #1/231:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #1/312:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #1/312:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #1/321:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #1/321:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #2/123:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #2/123:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #2/132:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #2/132:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #2/213:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #2/213:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #2/231:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #2/231:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #2/312:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #2/312:  ok  |  ok  |  ok  |
    hard-safe-A + unsafe-B #2/321:  ok  |  ok  |  ok  |
    soft-safe-A + unsafe-B #2/321:  ok  |  ok  |  ok  |
      hard-irq lock-inversion/123:  ok  |  ok  |  ok  |
      soft-irq lock-inversion/123:  ok  |  ok  |  ok  |
      hard-irq lock-inversion/132:  ok  |  ok  |  ok  |
      soft-irq lock-inversion/132:  ok  |  ok  |  ok  |
      hard-irq lock-inversion/213:  ok  |  ok  |  ok  |
      soft-irq lock-inversion/213:  ok  |  ok  |  ok  |
      hard-irq lock-inversion/231:  ok  |  ok  |  ok  |
      soft-irq lock-inversion/231:  ok  |  ok  |  ok  |
      hard-irq lock-inversion/312:  ok  |  ok  |  ok  |
      soft-irq lock-inversion/312:  ok  |  ok  |  ok  |
      hard-irq lock-inversion/321:  ok  |  ok  |  ok  |
      soft-irq lock-inversion/321:  ok  |  ok  |  ok  |
      hard-irq read-recursion/123:  ok  |
      soft-irq read-recursion/123:  ok  |
      hard-irq read-recursion/132:  ok  |
      soft-irq read-recursion/132:  ok  |
      hard-irq read-recursion/213:  ok  |
      soft-irq read-recursion/213:  ok  |
      hard-irq read-recursion/231:  ok  |
      soft-irq read-recursion/231:  ok  |
      hard-irq read-recursion/312:  ok  |
      soft-irq read-recursion/312:  ok  |
      hard-irq read-recursion/321:  ok  |
      soft-irq read-recursion/321:  ok  |
  --------------------------------+-----+----------------
  Good, all 210 testcases passed! |
  --------------------------------+

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

17 files changed, 1338 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 91e338a3d06..16021b09c18 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -149,6 +149,17 @@ config DEBUG_SPINLOCK_SLEEP
 	  If you say Y here, various routines which may sleep will become very
 	  noisy if they are called with a spinlock held.
 
+config DEBUG_LOCKING_API_SELFTESTS
+	bool "Locking API boot-time self-tests"
+	depends on DEBUG_KERNEL
+	help
+	  Say Y here if you want the kernel to run a short self-test during
+	  bootup. The self-test checks whether common types of locking bugs
+	  are detected by debugging mechanisms or not. (if you disable
+	  lock debugging then those bugs wont be detected of course.)
+	  The following locking APIs are covered: spinlocks, rwlocks,
+	  mutexes and rwsems.
+
 config STACKTRACE
 	bool
 	depends on STACKTRACE_SUPPORT
diff --git a/lib/Makefile b/lib/Makefile
index 4f5d01922f8..be9719ae82d 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -18,6 +18,7 @@ CFLAGS_kobject.o += -DDEBUG
 CFLAGS_kobject_uevent.o += -DDEBUG
 endif
 
+obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
 lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
 lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
diff --git a/lib/locking-selftest-hardirq.h b/lib/locking-selftest-hardirq.h
new file mode 100644
index 00000000000..10d4a150b25
--- /dev/null
+++ b/lib/locking-selftest-hardirq.h
@@ -0,0 +1,9 @@
+#undef IRQ_DISABLE
+#undef IRQ_ENABLE
+#undef IRQ_ENTER
+#undef IRQ_EXIT
+
+#define IRQ_ENABLE		HARDIRQ_ENABLE
+#define IRQ_DISABLE		HARDIRQ_DISABLE
+#define IRQ_ENTER		HARDIRQ_ENTER
+#define IRQ_EXIT		HARDIRQ_EXIT
diff --git a/lib/locking-selftest-mutex.h b/lib/locking-selftest-mutex.h
new file mode 100644
index 00000000000..68601b6f584
--- /dev/null
+++ b/lib/locking-selftest-mutex.h
@@ -0,0 +1,11 @@
+#undef LOCK
+#define LOCK		ML
+
+#undef UNLOCK
+#define UNLOCK		MU
+
+#undef RLOCK
+#undef WLOCK
+
+#undef INIT
+#define INIT		MI
diff --git a/lib/locking-selftest-rlock-hardirq.h b/lib/locking-selftest-rlock-hardirq.h
new file mode 100644
index 00000000000..9f517ebcb78
--- /dev/null
+++ b/lib/locking-selftest-rlock-hardirq.h
@@ -0,0 +1,2 @@
+#include "locking-selftest-rlock.h"
+#include "locking-selftest-hardirq.h"
diff --git a/lib/locking-selftest-rlock-softirq.h b/lib/locking-selftest-rlock-softirq.h
new file mode 100644
index 00000000000..981455db7ff
--- /dev/null
+++ b/lib/locking-selftest-rlock-softirq.h
@@ -0,0 +1,2 @@
+#include "locking-selftest-rlock.h"
+#include "locking-selftest-softirq.h"
diff --git a/lib/locking-selftest-rlock.h b/lib/locking-selftest-rlock.h
new file mode 100644
index 00000000000..6789044f4d0
--- /dev/null
+++ b/lib/locking-selftest-rlock.h
@@ -0,0 +1,14 @@
+#undef LOCK
+#define LOCK		RL
+
+#undef UNLOCK
+#define UNLOCK		RU
+
+#undef RLOCK
+#define RLOCK		RL
+
+#undef WLOCK
+#define WLOCK		WL
+
+#undef INIT
+#define INIT		RWI
diff --git a/lib/locking-selftest-rsem.h b/lib/locking-selftest-rsem.h
new file mode 100644
index 00000000000..62da886680c
--- /dev/null
+++ b/lib/locking-selftest-rsem.h
@@ -0,0 +1,14 @@
+#undef LOCK
+#define LOCK		RSL
+
+#undef UNLOCK
+#define UNLOCK		RSU
+
+#undef RLOCK
+#define RLOCK		RSL
+
+#undef WLOCK
+#define WLOCK		WSL
+
+#undef INIT
+#define INIT		RWSI
diff --git a/lib/locking-selftest-softirq.h b/lib/locking-selftest-softirq.h
new file mode 100644
index 00000000000..a83de2a04ac
--- /dev/null
+++ b/lib/locking-selftest-softirq.h
@@ -0,0 +1,9 @@
+#undef IRQ_DISABLE
+#undef IRQ_ENABLE
+#undef IRQ_ENTER
+#undef IRQ_EXIT
+
+#define IRQ_DISABLE		SOFTIRQ_DISABLE
+#define IRQ_ENABLE		SOFTIRQ_ENABLE
+#define IRQ_ENTER		SOFTIRQ_ENTER
+#define IRQ_EXIT		SOFTIRQ_EXIT
diff --git a/lib/locking-selftest-spin-hardirq.h b/lib/locking-selftest-spin-hardirq.h
new file mode 100644
index 00000000000..693198dce30
--- /dev/null
+++ b/lib/locking-selftest-spin-hardirq.h
@@ -0,0 +1,2 @@
+#include "locking-selftest-spin.h"
+#include "locking-selftest-hardirq.h"
diff --git a/lib/locking-selftest-spin-softirq.h b/lib/locking-selftest-spin-softirq.h
new file mode 100644
index 00000000000..c472e2a87ff
--- /dev/null
+++ b/lib/locking-selftest-spin-softirq.h
@@ -0,0 +1,2 @@
+#include "locking-selftest-spin.h"
+#include "locking-selftest-softirq.h"
diff --git a/lib/locking-selftest-spin.h b/lib/locking-selftest-spin.h
new file mode 100644
index 00000000000..ccd1b4b0975
--- /dev/null
+++ b/lib/locking-selftest-spin.h
@@ -0,0 +1,11 @@
+#undef LOCK
+#define LOCK		L
+
+#undef UNLOCK
+#define UNLOCK		U
+
+#undef RLOCK
+#undef WLOCK
+
+#undef INIT
+#define INIT		SI
diff --git a/lib/locking-selftest-wlock-hardirq.h b/lib/locking-selftest-wlock-hardirq.h
new file mode 100644
index 00000000000..2dd2e5122ca
--- /dev/null
+++ b/lib/locking-selftest-wlock-hardirq.h
@@ -0,0 +1,2 @@
+#include "locking-selftest-wlock.h"
+#include "locking-selftest-hardirq.h"
diff --git a/lib/locking-selftest-wlock-softirq.h b/lib/locking-selftest-wlock-softirq.h
new file mode 100644
index 00000000000..cb80d1cb944
--- /dev/null
+++ b/lib/locking-selftest-wlock-softirq.h
@@ -0,0 +1,2 @@
+#include "locking-selftest-wlock.h"
+#include "locking-selftest-softirq.h"
diff --git a/lib/locking-selftest-wlock.h b/lib/locking-selftest-wlock.h
new file mode 100644
index 00000000000..0815322d99e
--- /dev/null
+++ b/lib/locking-selftest-wlock.h
@@ -0,0 +1,14 @@
+#undef LOCK
+#define LOCK		WL
+
+#undef UNLOCK
+#define UNLOCK		WU
+
+#undef RLOCK
+#define RLOCK		RL
+
+#undef WLOCK
+#define WLOCK		WL
+
+#undef INIT
+#define INIT		RWI
diff --git a/lib/locking-selftest-wsem.h b/lib/locking-selftest-wsem.h
new file mode 100644
index 00000000000..b88c5f2dc5f
--- /dev/null
+++ b/lib/locking-selftest-wsem.h
@@ -0,0 +1,14 @@
+#undef LOCK
+#define LOCK		WSL
+
+#undef UNLOCK
+#define UNLOCK		WSU
+
+#undef RLOCK
+#define RLOCK		RSL
+
+#undef WLOCK
+#define WLOCK		WSL
+
+#undef INIT
+#define INIT		RWSI
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
new file mode 100644
index 00000000000..5cd05f20bde
--- /dev/null
+++ b/lib/locking-selftest.c
@@ -0,0 +1,1218 @@
+/*
+ * lib/locking-selftest.c
+ *
+ * Testsuite for various locking APIs: spinlocks, rwlocks,
+ * mutexes and rw-semaphores.
+ *
+ * It is checking both false positives and false negatives.
+ *
+ * Started by Ingo Molnar:
+ *
+ *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ */
+#include <linux/rwsem.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/kallsyms.h>
+#include <linux/interrupt.h>
+#include <linux/debug_locks.h>
+#include <linux/irqflags.h>
+
+/*
+ * Change this to 1 if you want to see the failure printouts:
+ */
+static unsigned int debug_locks_verbose;
+
+static int __init setup_debug_locks_verbose(char *str)
+{
+	get_option(&str, &debug_locks_verbose);
+
+	return 1;
+}
+
+__setup("debug_locks_verbose=", setup_debug_locks_verbose);
+
+#define FAILURE		0
+#define SUCCESS		1
+
+#define LOCKTYPE_SPIN	0x1
+#define LOCKTYPE_RWLOCK	0x2
+#define LOCKTYPE_MUTEX	0x4
+#define LOCKTYPE_RWSEM	0x8
+
+/*
+ * Normal standalone locks, for the circular and irq-context
+ * dependency tests:
+ */
+static DEFINE_SPINLOCK(lock_A);
+static DEFINE_SPINLOCK(lock_B);
+static DEFINE_SPINLOCK(lock_C);
+static DEFINE_SPINLOCK(lock_D);
+
+static DEFINE_RWLOCK(rwlock_A);
+static DEFINE_RWLOCK(rwlock_B);
+static DEFINE_RWLOCK(rwlock_C);
+static DEFINE_RWLOCK(rwlock_D);
+
+static DEFINE_MUTEX(mutex_A);
+static DEFINE_MUTEX(mutex_B);
+static DEFINE_MUTEX(mutex_C);
+static DEFINE_MUTEX(mutex_D);
+
+static DECLARE_RWSEM(rwsem_A);
+static DECLARE_RWSEM(rwsem_B);
+static DECLARE_RWSEM(rwsem_C);
+static DECLARE_RWSEM(rwsem_D);
+
+/*
+ * Locks that we initialize dynamically as well so that
+ * e.g. X1 and X2 becomes two instances of the same class,
+ * but X* and Y* are different classes. We do this so that
+ * we do not trigger a real lockup:
+ */
+static DEFINE_SPINLOCK(lock_X1);
+static DEFINE_SPINLOCK(lock_X2);
+static DEFINE_SPINLOCK(lock_Y1);
+static DEFINE_SPINLOCK(lock_Y2);
+static DEFINE_SPINLOCK(lock_Z1);
+static DEFINE_SPINLOCK(lock_Z2);
+
+static DEFINE_RWLOCK(rwlock_X1);
+static DEFINE_RWLOCK(rwlock_X2);
+static DEFINE_RWLOCK(rwlock_Y1);
+static DEFINE_RWLOCK(rwlock_Y2);
+static DEFINE_RWLOCK(rwlock_Z1);
+static DEFINE_RWLOCK(rwlock_Z2);
+
+static DEFINE_MUTEX(mutex_X1);
+static DEFINE_MUTEX(mutex_X2);
+static DEFINE_MUTEX(mutex_Y1);
+static DEFINE_MUTEX(mutex_Y2);
+static DEFINE_MUTEX(mutex_Z1);
+static DEFINE_MUTEX(mutex_Z2);
+
+static DECLARE_RWSEM(rwsem_X1);
+static DECLARE_RWSEM(rwsem_X2);
+static DECLARE_RWSEM(rwsem_Y1);
+static DECLARE_RWSEM(rwsem_Y2);
+static DECLARE_RWSEM(rwsem_Z1);
+static DECLARE_RWSEM(rwsem_Z2);
+
+/*
+ * non-inlined runtime initializers, to let separate locks share
+ * the same lock-class:
+ */
+#define INIT_CLASS_FUNC(class) 				\
+static noinline void					\
+init_class_##class(spinlock_t *lock, rwlock_t *rwlock, struct mutex *mutex, \
+		 struct rw_semaphore *rwsem)		\
+{							\
+	spin_lock_init(lock);				\
+	rwlock_init(rwlock);				\
+	mutex_init(mutex);				\
+	init_rwsem(rwsem);				\
+}
+
+INIT_CLASS_FUNC(X)
+INIT_CLASS_FUNC(Y)
+INIT_CLASS_FUNC(Z)
+
+static void init_shared_classes(void)
+{
+	init_class_X(&lock_X1, &rwlock_X1, &mutex_X1, &rwsem_X1);
+	init_class_X(&lock_X2, &rwlock_X2, &mutex_X2, &rwsem_X2);
+
+	init_class_Y(&lock_Y1, &rwlock_Y1, &mutex_Y1, &rwsem_Y1);
+	init_class_Y(&lock_Y2, &rwlock_Y2, &mutex_Y2, &rwsem_Y2);
+
+	init_class_Z(&lock_Z1, &rwlock_Z1, &mutex_Z1, &rwsem_Z1);
+	init_class_Z(&lock_Z2, &rwlock_Z2, &mutex_Z2, &rwsem_Z2);
+}
+
+/*
+ * For spinlocks and rwlocks we also do hardirq-safe / softirq-safe tests.
+ * The following functions use a lock from a simulated hardirq/softirq
+ * context, causing the locks to be marked as hardirq-safe/softirq-safe:
+ */
+
+#define HARDIRQ_DISABLE		local_irq_disable
+#define HARDIRQ_ENABLE		local_irq_enable
+
+#define HARDIRQ_ENTER()				\
+	local_irq_disable();			\
+	irq_enter();				\
+	WARN_ON(!in_irq());
+
+#define HARDIRQ_EXIT()				\
+	__irq_exit();				\
+	local_irq_enable();
+
+#define SOFTIRQ_DISABLE		local_bh_disable
+#define SOFTIRQ_ENABLE		local_bh_enable
+
+#define SOFTIRQ_ENTER()				\
+		local_bh_disable();		\
+		local_irq_disable();		\
+		trace_softirq_enter();		\
+		WARN_ON(!in_softirq());
+
+#define SOFTIRQ_EXIT()				\
+		trace_softirq_exit();		\
+		local_irq_enable();		\
+		local_bh_enable();
+
+/*
+ * Shortcuts for lock/unlock API variants, to keep
+ * the testcases compact:
+ */
+#define L(x)			spin_lock(&lock_##x)
+#define U(x)			spin_unlock(&lock_##x)
+#define LU(x)			L(x); U(x)
+#define SI(x)			spin_lock_init(&lock_##x)
+
+#define WL(x)			write_lock(&rwlock_##x)
+#define WU(x)			write_unlock(&rwlock_##x)
+#define WLU(x)			WL(x); WU(x)
+
+#define RL(x)			read_lock(&rwlock_##x)
+#define RU(x)			read_unlock(&rwlock_##x)
+#define RLU(x)			RL(x); RU(x)
+#define RWI(x)			rwlock_init(&rwlock_##x)
+
+#define ML(x)			mutex_lock(&mutex_##x)
+#define MU(x)			mutex_unlock(&mutex_##x)
+#define MI(x)			mutex_init(&mutex_##x)
+
+#define WSL(x)			down_write(&rwsem_##x)
+#define WSU(x)			up_write(&rwsem_##x)
+
+#define RSL(x)			down_read(&rwsem_##x)
+#define RSU(x)			up_read(&rwsem_##x)
+#define RWSI(x)			init_rwsem(&rwsem_##x)
+
+#define LOCK_UNLOCK_2(x,y)	LOCK(x); LOCK(y); UNLOCK(y); UNLOCK(x)
+
+/*
+ * Generate different permutations of the same testcase, using
+ * the same basic lock-dependency/state events:
+ */
+
+#define GENERATE_TESTCASE(name)			\
+						\
+static void name(void) { E(); }
+
+#define GENERATE_PERMUTATIONS_2_EVENTS(name)	\
+						\
+static void name##_12(void) { E1(); E2(); }	\
+static void name##_21(void) { E2(); E1(); }
+
+#define GENERATE_PERMUTATIONS_3_EVENTS(name)		\
+							\
+static void name##_123(void) { E1(); E2(); E3(); }	\
+static void name##_132(void) { E1(); E3(); E2(); }	\
+static void name##_213(void) { E2(); E1(); E3(); }	\
+static void name##_231(void) { E2(); E3(); E1(); }	\
+static void name##_312(void) { E3(); E1(); E2(); }	\
+static void name##_321(void) { E3(); E2(); E1(); }
+
+/*
+ * AA deadlock:
+ */
+
+#define E()					\
+						\
+	LOCK(X1);				\
+	LOCK(X2); /* this one should fail */
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(AA_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(AA_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(AA_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(AA_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(AA_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(AA_rsem)
+
+#undef E
+
+/*
+ * Special-case for read-locking, they are
+ * allowed to recurse on the same lock instance:
+ */
+static void rlock_AA1(void)
+{
+	RL(X1);
+	RL(X1); // this one should NOT fail
+}
+
+static void rlock_AA1B(void)
+{
+	RL(X1);
+	RL(X2); // this one should fail
+}
+
+static void rsem_AA1(void)
+{
+	RSL(X1);
+	RSL(X1); // this one should fail
+}
+
+static void rsem_AA1B(void)
+{
+	RSL(X1);
+	RSL(X2); // this one should fail
+}
+/*
+ * The mixing of read and write locks is not allowed:
+ */
+static void rlock_AA2(void)
+{
+	RL(X1);
+	WL(X2); // this one should fail
+}
+
+static void rsem_AA2(void)
+{
+	RSL(X1);
+	WSL(X2); // this one should fail
+}
+
+static void rlock_AA3(void)
+{
+	WL(X1);
+	RL(X2); // this one should fail
+}
+
+static void rsem_AA3(void)
+{
+	WSL(X1);
+	RSL(X2); // this one should fail
+}
+
+/*
+ * ABBA deadlock:
+ */
+
+#define E()					\
+						\
+	LOCK_UNLOCK_2(A, B);			\
+	LOCK_UNLOCK_2(B, A); /* fail */
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(ABBA_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(ABBA_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(ABBA_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(ABBA_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(ABBA_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(ABBA_rsem)
+
+#undef E
+
+/*
+ * AB BC CA deadlock:
+ */
+
+#define E()					\
+						\
+	LOCK_UNLOCK_2(A, B);			\
+	LOCK_UNLOCK_2(B, C);			\
+	LOCK_UNLOCK_2(C, A); /* fail */
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(ABBCCA_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(ABBCCA_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(ABBCCA_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(ABBCCA_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(ABBCCA_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(ABBCCA_rsem)
+
+#undef E
+
+/*
+ * AB CA BC deadlock:
+ */
+
+#define E()					\
+						\
+	LOCK_UNLOCK_2(A, B);			\
+	LOCK_UNLOCK_2(C, A);			\
+	LOCK_UNLOCK_2(B, C); /* fail */
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(ABCABC_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(ABCABC_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(ABCABC_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(ABCABC_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(ABCABC_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(ABCABC_rsem)
+
+#undef E
+
+/*
+ * AB BC CD DA deadlock:
+ */
+
+#define E()					\
+						\
+	LOCK_UNLOCK_2(A, B);			\
+	LOCK_UNLOCK_2(B, C);			\
+	LOCK_UNLOCK_2(C, D);			\
+	LOCK_UNLOCK_2(D, A); /* fail */
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(ABBCCDDA_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(ABBCCDDA_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(ABBCCDDA_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(ABBCCDDA_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(ABBCCDDA_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(ABBCCDDA_rsem)
+
+#undef E
+
+/*
+ * AB CD BD DA deadlock:
+ */
+#define E()					\
+						\
+	LOCK_UNLOCK_2(A, B);			\
+	LOCK_UNLOCK_2(C, D);			\
+	LOCK_UNLOCK_2(B, D);			\
+	LOCK_UNLOCK_2(D, A); /* fail */
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(ABCDBDDA_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(ABCDBDDA_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(ABCDBDDA_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(ABCDBDDA_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(ABCDBDDA_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(ABCDBDDA_rsem)
+
+#undef E
+
+/*
+ * AB CD BC DA deadlock:
+ */
+#define E()					\
+						\
+	LOCK_UNLOCK_2(A, B);			\
+	LOCK_UNLOCK_2(C, D);			\
+	LOCK_UNLOCK_2(B, C);			\
+	LOCK_UNLOCK_2(D, A); /* fail */
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(ABCDBCDA_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(ABCDBCDA_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(ABCDBCDA_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(ABCDBCDA_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(ABCDBCDA_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(ABCDBCDA_rsem)
+
+#undef E
+
+/*
+ * Double unlock:
+ */
+#define E()					\
+						\
+	LOCK(A);				\
+	UNLOCK(A);				\
+	UNLOCK(A); /* fail */
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(double_unlock_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(double_unlock_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(double_unlock_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(double_unlock_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(double_unlock_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(double_unlock_rsem)
+
+#undef E
+
+/*
+ * Bad unlock ordering:
+ */
+#define E()					\
+						\
+	LOCK(A);				\
+	LOCK(B);				\
+	UNLOCK(A); /* fail */			\
+	UNLOCK(B);
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(bad_unlock_order_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(bad_unlock_order_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(bad_unlock_order_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(bad_unlock_order_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(bad_unlock_order_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(bad_unlock_order_rsem)
+
+#undef E
+
+/*
+ * initializing a held lock:
+ */
+#define E()					\
+						\
+	LOCK(A);				\
+	INIT(A); /* fail */
+
+/*
+ * 6 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_TESTCASE(init_held_spin)
+#include "locking-selftest-wlock.h"
+GENERATE_TESTCASE(init_held_wlock)
+#include "locking-selftest-rlock.h"
+GENERATE_TESTCASE(init_held_rlock)
+#include "locking-selftest-mutex.h"
+GENERATE_TESTCASE(init_held_mutex)
+#include "locking-selftest-wsem.h"
+GENERATE_TESTCASE(init_held_wsem)
+#include "locking-selftest-rsem.h"
+GENERATE_TESTCASE(init_held_rsem)
+
+#undef E
+
+/*
+ * locking an irq-safe lock with irqs enabled:
+ */
+#define E1()				\
+					\
+	IRQ_ENTER();			\
+	LOCK(A);			\
+	UNLOCK(A);			\
+	IRQ_EXIT();
+
+#define E2()				\
+					\
+	LOCK(A);			\
+	UNLOCK(A);
+
+/*
+ * Generate 24 testcases:
+ */
+#include "locking-selftest-spin-hardirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_spin)
+
+#include "locking-selftest-rlock-hardirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_rlock)
+
+#include "locking-selftest-wlock-hardirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_wlock)
+
+#include "locking-selftest-spin-softirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_spin)
+
+#include "locking-selftest-rlock-softirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_rlock)
+
+#include "locking-selftest-wlock-softirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_wlock)
+
+#undef E1
+#undef E2
+
+/*
+ * Enabling hardirqs with a softirq-safe lock held:
+ */
+#define E1()				\
+					\
+	SOFTIRQ_ENTER();		\
+	LOCK(A);			\
+	UNLOCK(A);			\
+	SOFTIRQ_EXIT();
+
+#define E2()				\
+					\
+	HARDIRQ_DISABLE();		\
+	LOCK(A);			\
+	HARDIRQ_ENABLE();		\
+	UNLOCK(A);
+
+/*
+ * Generate 12 testcases:
+ */
+#include "locking-selftest-spin.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_spin)
+
+#include "locking-selftest-wlock.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_wlock)
+
+#include "locking-selftest-rlock.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_rlock)
+
+#undef E1
+#undef E2
+
+/*
+ * Enabling irqs with an irq-safe lock held:
+ */
+#define E1()				\
+					\
+	IRQ_ENTER();			\
+	LOCK(A);			\
+	UNLOCK(A);			\
+	IRQ_EXIT();
+
+#define E2()				\
+					\
+	IRQ_DISABLE();			\
+	LOCK(A);			\
+	IRQ_ENABLE();			\
+	UNLOCK(A);
+
+/*
+ * Generate 24 testcases:
+ */
+#include "locking-selftest-spin-hardirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_spin)
+
+#include "locking-selftest-rlock-hardirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_rlock)
+
+#include "locking-selftest-wlock-hardirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_wlock)
+
+#include "locking-selftest-spin-softirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_spin)
+
+#include "locking-selftest-rlock-softirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_rlock)
+
+#include "locking-selftest-wlock-softirq.h"
+GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_wlock)
+
+#undef E1
+#undef E2
+
+/*
+ * Acquiring a irq-unsafe lock while holding an irq-safe-lock:
+ */
+#define E1()				\
+					\
+	LOCK(A);			\
+	LOCK(B);			\
+	UNLOCK(B);			\
+	UNLOCK(A);			\
+
+#define E2()				\
+					\
+	LOCK(B);			\
+	UNLOCK(B);
+
+#define E3()				\
+					\
+	IRQ_ENTER();			\
+	LOCK(A);			\
+	UNLOCK(A);			\
+	IRQ_EXIT();
+
+/*
+ * Generate 36 testcases:
+ */
+#include "locking-selftest-spin-hardirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_spin)
+
+#include "locking-selftest-rlock-hardirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_rlock)
+
+#include "locking-selftest-wlock-hardirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_wlock)
+
+#include "locking-selftest-spin-softirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_spin)
+
+#include "locking-selftest-rlock-softirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_rlock)
+
+#include "locking-selftest-wlock-softirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_wlock)
+
+#undef E1
+#undef E2
+#undef E3
+
+/*
+ * If a lock turns into softirq-safe, but earlier it took
+ * a softirq-unsafe lock:
+ */
+
+#define E1()				\
+	IRQ_DISABLE();			\
+	LOCK(A);			\
+	LOCK(B);			\
+	UNLOCK(B);			\
+	UNLOCK(A);			\
+	IRQ_ENABLE();
+
+#define E2()				\
+	LOCK(B);			\
+	UNLOCK(B);
+
+#define E3()				\
+	IRQ_ENTER();			\
+	LOCK(A);			\
+	UNLOCK(A);			\
+	IRQ_EXIT();
+
+/*
+ * Generate 36 testcases:
+ */
+#include "locking-selftest-spin-hardirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_spin)
+
+#include "locking-selftest-rlock-hardirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_rlock)
+
+#include "locking-selftest-wlock-hardirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_wlock)
+
+#include "locking-selftest-spin-softirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_spin)
+
+#include "locking-selftest-rlock-softirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_rlock)
+
+#include "locking-selftest-wlock-softirq.h"
+GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_wlock)
+
+#undef E1
+#undef E2
+#undef E3
+
+/*
+ * read-lock / write-lock irq inversion.
+ *
+ * Deadlock scenario:
+ *
+ * CPU#1 is at #1, i.e. it has write-locked A, but has not
+ * taken B yet.
+ *
+ * CPU#2 is at #2, i.e. it has locked B.
+ *
+ * Hardirq hits CPU#2 at point #2 and is trying to read-lock A.
+ *
+ * The deadlock occurs because CPU#1 will spin on B, and CPU#2
+ * will spin on A.
+ */
+
+#define E1()				\
+					\
+	IRQ_DISABLE();			\
+	WL(A);				\
+	LOCK(B);			\
+	UNLOCK(B);			\
+	WU(A);				\
+	IRQ_ENABLE();
+
+#define E2()				\
+					\
+	LOCK(B);			\
+	UNLOCK(B);
+