Rework the witness code to work with sx locks as well as mutexes.

- Introduce lock classes and lock objects.  Each lock class specifies a
  name and set of flags (or properties) shared by all locks of a given
  type.  Currently there are three lock classes: spin mutexes, sleep
  mutexes, and sx locks.  A lock object specifies properties of an
  additional lock along with a lock name and all of the extra stuff needed
  to make witness work with a given lock.  This abstract lock stuff is
  defined in sys/lock.h.  The lockmgr constants, types, and prototypes have
  been moved to sys/lockmgr.h.  For temporary backwards compatability,
  sys/lock.h includes sys/lockmgr.h.
- Replace proc->p_spinlocks with a per-CPU list, PCPU(spinlocks), of spin
  locks held.  By making this per-cpu, we do not have to jump through
  magic hoops to deal with sched_lock changing ownership during context
  switches.
- Replace proc->p_heldmtx, formerly a list of held sleep mutexes, with
  proc->p_sleeplocks, which is a list of held sleep locks including sleep
  mutexes and sx locks.
- Add helper macros for logging lock events via the KTR_LOCK KTR logging
  level so that the log messages are consistent.
- Add some new flags that can be passed to mtx_init():
  - MTX_NOWITNESS - specifies that this lock should be ignored by witness.
    This is used for the mutex that blocks a sx lock for example.
  - MTX_QUIET - this is not new, but you can pass this to mtx_init() now
    and no events will be logged for this lock, so that one doesn't have
    to change all the individual mtx_lock/unlock() operations.
- All lock objects maintain an initialized flag.  Use this flag to export
  a mtx_initialized() macro that can be safely called from drivers.  Also,
  we on longer walk the all_mtx list if MUTEX_DEBUG is defined as witness
  performs the corresponding checks using the initialized flag.
- The lock order reversal messages have been improved to output slightly
  more accurate file and line numbers.

1 files changed, 17 insertions, 9 deletions

diff --git a/sys/sys/sx.h b/sys/sys/sx.h
index 2c5c9812e621..3b4114d704ea 100644
--- a/sys/sys/sx.h
+++ b/sys/sys/sx.h
@@ -31,12 +31,15 @@
 #define	_SYS_SX_H_
 
 #ifndef	LOCORE
-#include <sys/mutex.h>
-#include <sys/condvar.h>
+#include <sys/lock.h>		/* XXX */
+#include <sys/mutex.h>		/* XXX */
+#include <sys/condvar.h>	/* XXX */
+
+struct lock_object;
 
 struct sx {
+	struct lock_object sx_object;	/* Common lock properties. */
 	struct mtx	sx_lock;	/* General protection lock. */
-	const char	*sx_descr;	/* sx lock description. */
 	int		sx_cnt;		/* -1: xlock, > 0: slock count. */
 	struct cv	sx_shrd_cv;	/* slock waiters. */
 	int		sx_shrd_wcnt;	/* Number of slock waiters. */
@@ -48,10 +51,15 @@ struct sx {
 #ifdef _KERNEL
 void	sx_init(struct sx *sx, const char *description);
 void	sx_destroy(struct sx *sx);
-void	sx_slock(struct sx *sx);
-void	sx_xlock(struct sx *sx);
-void	sx_sunlock(struct sx *sx);
-void	sx_xunlock(struct sx *sx);
+void	_sx_slock(struct sx *sx, const char *file, int line);
+void	_sx_xlock(struct sx *sx, const char *file, int line);
+void	_sx_sunlock(struct sx *sx, const char *file, int line);
+void	_sx_xunlock(struct sx *sx, const char *file, int line);
+
+#define	sx_slock(sx)	_sx_slock((sx), __FILE__, __LINE__)
+#define	sx_xlock(sx)	_sx_xlock((sx), __FILE__, __LINE__)
+#define	sx_sunlock(sx)	_sx_sunlock((sx), __FILE__, __LINE__)
+#define	sx_xunlock(sx)	_sx_xunlock((sx), __FILE__, __LINE__)
 
 #ifdef INVARIANTS
 /*
@@ -65,7 +73,7 @@ void	sx_xunlock(struct sx *sx);
 } while (0)
 #define	_SX_ASSERT_SLOCKED(sx) do {					\
 	KASSERT(((sx)->sx_cnt > 0), ("%s: lacking slock %s\n",		\
-	    __FUNCTION__, (sx)->sx_descr));				\
+	    __FUNCTION__, (sx)->sx_object.lo_name));			\
 } while (0)
 
 /*
@@ -79,7 +87,7 @@ void	sx_xunlock(struct sx *sx);
 #define	_SX_ASSERT_XLOCKED(sx) do {					\
 	KASSERT(((sx)->sx_xholder == curproc),				\
 	    ("%s: thread %p lacking xlock %s\n", __FUNCTION__,		\
-	    curproc, (sx)->sx_descr));					\
+	    curproc, (sx)->sx_object.lo_name));				\
 } while (0)
 
 #else	/* INVARIANTS */