From 347cb29151859a56a6c5f0f355a43033e5e035a5 Mon Sep 17 00:00:00 2001
From: Justus Winter <4winter@informatik.uni-hamburg.de>
Date: Sat, 15 Aug 2015 17:04:08 +0200
Subject: kern: improve simple lock debugging

Do not bother saving the return address when acquire a simple lock.
Save the location as provided by the compiler as string instead.  Also
save the lock parameter.

* kern/lock.c (struct simple_locks_info): Drop `ra', add `expr', `loc'.
(simple_lock): Rename to `_simple_lock', add expression and location
parameters and save them.
(simple_lock_try): Likewise.
(simple_unlock): Zero-out the now unused slot in the list of taken locks.
(db_show_all_slocks): Use the new information.
* kern/lock.h (simple_lock, simple_lock_try): Provide macro versions
passing the location and expression as string.
---
 kern/lock.h | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

(limited to 'kern/lock.h')

diff --git a/kern/lock.h b/kern/lock.h
index 0eba0ad1..e88e1824 100644
--- a/kern/lock.h
+++ b/kern/lock.h
@@ -90,9 +90,20 @@ class	simple_lock_data_t	name;
  */
 
 extern void		simple_lock_init(simple_lock_t);
-extern void		simple_lock(simple_lock_t);
+extern void		_simple_lock(simple_lock_t,
+				     const char *, const char *);
 extern void		simple_unlock(simple_lock_t);
-extern boolean_t	simple_lock_try(simple_lock_t);
+extern boolean_t	_simple_lock_try(simple_lock_t,
+					 const char *, const char *);
+
+/* We provide simple_lock and simple_lock_try so that we can save the
+   location.  */
+#define XSTR(x)		#x
+#define STR(x)		XSTR(x)
+#define LOCATION	__FILE__ ":" STR(__LINE__)
+
+#define simple_lock(lock)	_simple_lock((lock), #lock, LOCATION)
+#define simple_lock_try(lock)	_simple_lock_try((lock), #lock, LOCATION)
 
 #define simple_lock_pause()
 #define simple_lock_taken(lock)		(simple_lock_assert(lock),	\
-- 
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