Hook up mutex(9) to witness(4).

2 files changed, 74 insertions, 1 deletions

diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
new file mode 100644
index 00000000000..6ede70b2d80
--- /dev/null
+++ b/sys/kern/kern_mutex.c
@@ -0,0 +1,69 @@
+/*	$OpenBSD: kern_mutex.c,v 1.1 2017/04/20 13:57:30 visa Exp $	*/
+
+/*
+ * Copyright (c) 2017 Visa Hankala
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/mutex.h>
+#include <sys/witness.h>
+
+void
+_mtx_init_flags(struct mutex *m, int ipl, const char *name, int flags,
+    struct lock_type *type)
+{
+	struct lock_object *lo = MUTEX_LOCK_OBJECT(m);
+
+	lo->lo_flags = MTX_LO_FLAGS(flags);
+	if (name != NULL)
+		lo->lo_name = name;
+	else
+		lo->lo_name = type->lt_name;
+	WITNESS_INIT(lo, type);
+
+	_mtx_init(m, ipl);
+}
+
+void
+_mtx_enter(struct mutex *m, const char *file, int line)
+{
+	struct lock_object *lo = MUTEX_LOCK_OBJECT(m);
+
+	WITNESS_CHECKORDER(lo, LOP_EXCLUSIVE | LOP_NEWORDER, file, line, NULL);
+	__mtx_enter(m);
+	WITNESS_LOCK(lo, LOP_EXCLUSIVE, file, line);
+}
+
+int
+_mtx_enter_try(struct mutex *m, const char *file, int line)
+{
+	struct lock_object *lo = MUTEX_LOCK_OBJECT(m);
+
+	if (__mtx_enter_try(m)) {
+		WITNESS_LOCK(lo, LOP_EXCLUSIVE, file, line);
+		return 1;
+	}
+	return 0;
+}
+
+void
+_mtx_leave(struct mutex *m, const char *file, int line)
+{
+	struct lock_object *lo = MUTEX_LOCK_OBJECT(m);
+
+	WITNESS_UNLOCK(lo, LOP_EXCLUSIVE, file, line);
+	__mtx_leave(m);
+}
diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index 79ff976529a..9925025e304 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_synch.c,v 1.139 2017/04/20 13:33:00 visa Exp $	*/
+/*	$OpenBSD: kern_synch.c,v 1.140 2017/04/20 13:57:30 visa Exp $	*/
 /*	$NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $	*/
 
 /*
@@ -170,6 +170,7 @@ msleep(const volatile void *ident, struct mutex *mtx, int priority,
 #ifdef MULTIPROCESSOR
 	int hold_count;
 #endif
+	WITNESS_SAVE_DECL(lock_fl);
 
 	KASSERT((priority & ~(PRIMASK | PCATCH | PNORELOCK)) == 0);
 	KASSERT(mtx != NULL);
@@ -202,6 +203,8 @@ msleep(const volatile void *ident, struct mutex *mtx, int priority,
 	sleep_setup_timeout(&sls, timo);
 	sleep_setup_signal(&sls, priority);
 
+	WITNESS_SAVE(MUTEX_LOCK_OBJECT(mtx), lock_fl);
+
 	/* XXX - We need to make sure that the mutex doesn't
 	 * unblock splsched. This can be made a bit more
 	 * correct when the sched_lock is a mutex.
@@ -217,6 +220,7 @@ msleep(const volatile void *ident, struct mutex *mtx, int priority,
 	if ((priority & PNORELOCK) == 0) {
 		mtx_enter(mtx);
 		MUTEX_OLDIPL(mtx) = spl; /* put the ipl back */
+		WITNESS_RESTORE(MUTEX_LOCK_OBJECT(mtx), lock_fl);
 	} else
 		splx(spl);