From 46333fa556c039ed915ed4cab16345fcb3a7c0c1 Mon Sep 17 00:00:00 2001
From: jhb <jhb@FreeBSD.org>
Date: Wed, 7 Mar 2001 02:45:15 +0000
Subject: [PATCH] - Add an extra check in priority_propagation() for UP systems
 to ensure we   don't end up back at ourselves which would indicate deadlock.
 - Add the proc lock to the witness dup_list as we may hold more than one  
 process lock at a time. - Don't assert a mutex is owned in
 _mtx_unlock_sleep() as that is too late.   We do the checks in the macros
 instead.

---
 sys/kern/kern_mutex.c     | 10 +++++++++-
 sys/kern/subr_turnstile.c | 10 +++++++++-
 sys/kern/subr_witness.c   | 10 +++++++++-
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
index 2142de0a47a7..1ca5cca6eaab 100644
--- a/sys/kern/kern_mutex.c
+++ b/sys/kern/kern_mutex.c
@@ -216,6 +216,14 @@ propagate_priority(struct proc *p)
 			return;
 		}
 
+#ifndef SMP
+		/*
+		 * For UP, we check to see if p is curproc (this shouldn't
+		 * ever happen however as it would mean we are in a deadlock.)
+		 */
+		KASSERT(p != curproc, ("Deadlock detected"));
+#endif
+
 		/*
 		 * If on run queue move to new run queue, and
 		 * quit.
@@ -501,7 +509,6 @@ _mtx_unlock_sleep(struct mtx *m, int opts, const char *file, int line)
 	int pri;
 
 	p = curproc;
-	MPASS4(mtx_owned(m), "mtx_owned(mpp)", file, line);
 
 	if (mtx_recursed(m)) {
 		if (--(m->mtx_recurse) == 0)
@@ -949,6 +956,7 @@ static char *order_list[] = {
 };
 
 static char *dup_list[] = {
+	"process lock",
 	NULL
 };
 
diff --git a/sys/kern/subr_turnstile.c b/sys/kern/subr_turnstile.c
index 2142de0a47a7..1ca5cca6eaab 100644
--- a/sys/kern/subr_turnstile.c
+++ b/sys/kern/subr_turnstile.c
@@ -216,6 +216,14 @@ propagate_priority(struct proc *p)
 			return;
 		}
 
+#ifndef SMP
+		/*
+		 * For UP, we check to see if p is curproc (this shouldn't
+		 * ever happen however as it would mean we are in a deadlock.)
+		 */
+		KASSERT(p != curproc, ("Deadlock detected"));
+#endif
+
 		/*
 		 * If on run queue move to new run queue, and
 		 * quit.
@@ -501,7 +509,6 @@ _mtx_unlock_sleep(struct mtx *m, int opts, const char *file, int line)
 	int pri;
 
 	p = curproc;
-	MPASS4(mtx_owned(m), "mtx_owned(mpp)", file, line);
 
 	if (mtx_recursed(m)) {
 		if (--(m->mtx_recurse) == 0)
@@ -949,6 +956,7 @@ static char *order_list[] = {
 };
 
 static char *dup_list[] = {
+	"process lock",
 	NULL
 };
 
diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c
index 2142de0a47a7..1ca5cca6eaab 100644
--- a/sys/kern/subr_witness.c
+++ b/sys/kern/subr_witness.c
@@ -216,6 +216,14 @@ propagate_priority(struct proc *p)
 			return;
 		}
 
+#ifndef SMP
+		/*
+		 * For UP, we check to see if p is curproc (this shouldn't
+		 * ever happen however as it would mean we are in a deadlock.)
+		 */
+		KASSERT(p != curproc, ("Deadlock detected"));
+#endif
+
 		/*
 		 * If on run queue move to new run queue, and
 		 * quit.
@@ -501,7 +509,6 @@ _mtx_unlock_sleep(struct mtx *m, int opts, const char *file, int line)
 	int pri;
 
 	p = curproc;
-	MPASS4(mtx_owned(m), "mtx_owned(mpp)", file, line);
 
 	if (mtx_recursed(m)) {
 		if (--(m->mtx_recurse) == 0)
@@ -949,6 +956,7 @@ static char *order_list[] = {
 };
 
 static char *dup_list[] = {
+	"process lock",
 	NULL
 };