1 files changed, 136 insertions, 0 deletions
diff --git a/debian/patches/fix-locking0004-yyy-kern-keep-track-of-the-writer-when-debugging-loc.patch b/debian/patches/fix-locking0004-yyy-kern-keep-track-of-the-writer-when-debugging-loc.patch
new file mode 100644
index 0000000..8d93a6c
--- /dev/null
+++ b/debian/patches/fix-locking0004-yyy-kern-keep-track-of-the-writer-when-debugging-loc.patch
@@ -0,0 +1,136 @@
+From 527997b2efdb6bd14cc051dd85a0d4940bc453dc Mon Sep 17 00:00:00 2001
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Date: Sat, 15 Aug 2015 18:30:28 +0200
+Subject: [PATCH gnumach 04/12] yyy kern: keep track of the writer when
+ debugging locks
+
+* kern/lock.c
+* kern/lock.h
+---
+ kern/lock.c | 28 +++++++++++++++++++++++++++-
+ kern/lock.h | 13 +++++++++++++
+ 2 files changed, 40 insertions(+), 1 deletion(-)
+
+diff --git a/kern/lock.c b/kern/lock.c
+index de22795..46c78da 100644
+--- a/kern/lock.c
++++ b/kern/lock.c
+@@ -318,6 +318,9 @@ void lock_write(
+ 			simple_lock(&l->interlock);
+ 		}
+ 	}
++#if MACH_LDEBUG
++	l->writer = current_thread();
++#endif	/* MACH_LDEBUG */
+ 	simple_unlock(&l->interlock);
+ }
+ 
+@@ -334,8 +337,12 @@ void lock_done(
+ 	else
+ 	if (l->want_upgrade)
+ 	 	l->want_upgrade = FALSE;
+-	else
++	else {
+ 	 	l->want_write = FALSE;
++#if MACH_LDEBUG
++		l->writer = THREAD_NULL;
++#endif	/* MACH_LDEBUG */
++	}
+ 
+ 	/*
+ 	 *	There is no reason to wakeup a waiting thread
+@@ -452,6 +459,9 @@ boolean_t lock_read_to_write(
+ 		}
+ 	}
+ 
++#if MACH_LDEBUG
++	l->writer = current_thread();
++#endif	/* MACH_LDEBUG */
+ 	simple_unlock(&l->interlock);
+ 	return FALSE;
+ }
+@@ -460,6 +470,9 @@ void lock_write_to_read(
+ 	lock_t	l)
+ {
+ 	simple_lock(&l->interlock);
++#if MACH_LDEBUG
++	assert(l->writer == current_thread());
++#endif	/* MACH_LDEBUG */
+ 
+ 	l->read_count++;
+ 	if (l->recursion_depth != 0)
+@@ -475,6 +488,9 @@ void lock_write_to_read(
+ 		thread_wakeup(l);
+ 	}
+ 
++#if MACH_LDEBUG
++	l->writer = THREAD_NULL;
++#endif	/* MACH_LDEBUG */
+ 	simple_unlock(&l->interlock);
+ }
+ 
+@@ -514,6 +530,9 @@ boolean_t lock_try_write(
+ 	 */
+ 
+ 	l->want_write = TRUE;
++#if MACH_LDEBUG
++	l->writer = current_thread();
++#endif	/* MACH_LDEBUG */
+ 	simple_unlock(&l->interlock);
+ 	return TRUE;
+ }
+@@ -590,6 +609,9 @@ boolean_t lock_try_read_to_write(
+ 		simple_lock(&l->interlock);
+ 	}
+ 
++#if MACH_LDEBUG
++	l->writer = current_thread();
++#endif	/* MACH_LDEBUG */
+ 	simple_unlock(&l->interlock);
+ 	return TRUE;
+ }
+@@ -602,6 +624,10 @@ void lock_set_recursive(
+ 	lock_t		l)
+ {
+ 	simple_lock(&l->interlock);
++#if MACH_LDEBUG
++	assert(l->writer == current_thread());
++#endif	/* MACH_LDEBUG */
++
+ 	if (!l->want_write) {
+ 		panic("lock_set_recursive: don't have write lock");
+ 	}
+diff --git a/kern/lock.h b/kern/lock.h
+index e88e182..b237a94 100644
+--- a/kern/lock.h
++++ b/kern/lock.h
+@@ -174,6 +174,9 @@ struct lock {
+ 	/* boolean_t */	can_sleep:1,	/* Can attempts to lock go to sleep? */
+ 			recursion_depth:12, /* Depth of recursion */
+ 			:0; 
++#if MACH_LDEBUG
++	struct thread	*writer;
++#endif	/* MACH_LDEBUG */
+ 	decl_simple_lock_data(,interlock)
+ 					/* Hardware interlock field.
+ 					   Last in the structure so that
+@@ -203,6 +206,16 @@ extern boolean_t	lock_try_read_to_write(lock_t);
+ extern void		lock_set_recursive(lock_t);
+ extern void		lock_clear_recursive(lock_t);
+ 
++/* Lock debugging support.  */
++#if	! MACH_LDEBUG
++#define have_read_lock(l)	1
++#define have_write_lock(l)	1
++#else	/* MACH_LDEBUG */
++#define have_read_lock(l)	((l)->read_count > 0)
++#define have_write_lock(l)	((l)->writer == current_thread())
++#endif	/* MACH_LDEBUG */
++#define have_lock(l)		(have_read_lock(l) || have_write_lock(l))
++
+ void db_show_all_slocks(void);
+ 
+ #endif	/* _KERN_LOCK_H_ */
+-- 
+2.1.4
+