- Replace the series of DEBUG_LOCKS hacks which tried to save the vn_lock

   caller by saving the stack of the last locker/unlocker in lockmgr.  We
   also put the stack in KTR at the moment.

Contributed by:		Antoine Brodin <antoine.brodin@laposte.net>

1 files changed, 15 insertions, 34 deletions

diff --git a/sys/kern/kern_lock.c b/sys/kern/kern_lock.c
index 55acab6..375015f 100644
--- a/sys/kern/kern_lock.c
+++ b/sys/kern/kern_lock.c
@@ -51,6 +51,10 @@ __FBSDID("$FreeBSD$");
 #include <sys/mutex.h>
 #include <sys/proc.h>
 #include <sys/systm.h>
+#ifdef DEBUG_LOCKS
+#include <sys/stack.h>
+#include <sys/sysctl.h>
+#endif
 
 /*
  * Locking primitives implementation.
@@ -138,20 +142,11 @@ acquire(struct lock **lkpp, int extflags, int wanted)
  * accepted shared locks and shared-to-exclusive upgrades to go away.
  */
 int
-#ifndef	DEBUG_LOCKS
 lockmgr(lkp, flags, interlkp, td)
-#else
-debuglockmgr(lkp, flags, interlkp, td, name, file, line)
-#endif
 	struct lock *lkp;
 	u_int flags;
 	struct mtx *interlkp;
 	struct thread *td;
-#ifdef	DEBUG_LOCKS
-	const char *name;	/* Name of lock function */
-	const char *file;	/* Name of file call is from */
-	int line;		/* Line number in file */
-#endif
 {
 	int error;
 	struct thread *thr;
@@ -165,15 +160,16 @@ debuglockmgr(lkp, flags, interlkp, td, name, file, line)
 
 	if ((flags & LK_INTERNAL) == 0)
 		mtx_lock(lkp->lk_interlock);
-#ifdef DEBUG_LOCKS
-	CTR6(KTR_LOCK,
-	    "lockmgr(): lkp == %p (lk_wmesg == \"%s\"), flags == 0x%x, "
-	    "td == %p %s:%d", lkp, lkp->lk_wmesg, flags, td, file, line);
-#else
 	CTR6(KTR_LOCK,
 	    "lockmgr(): lkp == %p (lk_wmesg == \"%s\"), owner == %p, exclusivecount == %d, flags == 0x%x, "
 	    "td == %p", lkp, lkp->lk_wmesg, lkp->lk_lockholder,
 	    lkp->lk_exclusivecount, flags, td);
+#ifdef DEBUG_LOCKS
+	{
+		struct stack stack; /* XXX */
+		stack_save(&stack);
+		CTRSTACK(KTR_LOCK, &stack, 1);
+	}
 #endif
 
 	if (flags & LK_INTERLOCK) {
@@ -218,10 +214,7 @@ debuglockmgr(lkp, flags, interlkp, td, name, file, line)
 				break;
 			sharelock(td, lkp, 1);
 #if defined(DEBUG_LOCKS)
-			lkp->lk_slockholder = thr;
-			lkp->lk_sfilename = file;
-			lkp->lk_slineno = line;
-			lkp->lk_slockername = name;
+			stack_save(&lkp->stack);
 #endif
 			break;
 		}
@@ -304,9 +297,7 @@ debuglockmgr(lkp, flags, interlkp, td, name, file, line)
 			lkp->lk_exclusivecount = 1;
 			COUNT(td, 1);
 #if defined(DEBUG_LOCKS)
-			lkp->lk_filename = file;
-			lkp->lk_lineno = line;
-			lkp->lk_lockername = name;
+			stack_save(&lkp->stack);
 #endif
 			break;
 		}
@@ -365,9 +356,7 @@ debuglockmgr(lkp, flags, interlkp, td, name, file, line)
 		lkp->lk_exclusivecount = 1;
 		COUNT(td, 1);
 #if defined(DEBUG_LOCKS)
-			lkp->lk_filename = file;
-			lkp->lk_lineno = line;
-			lkp->lk_lockername = name;
+		stack_save(&lkp->stack);
 #endif
 		break;
 
@@ -412,9 +401,7 @@ debuglockmgr(lkp, flags, interlkp, td, name, file, line)
 		lkp->lk_exclusivecount = 1;
 		COUNT(td, 1);
 #if defined(DEBUG_LOCKS)
-			lkp->lk_filename = file;
-			lkp->lk_lineno = line;
-			lkp->lk_lockername = name;
+		stack_save(&lkp->stack);
 #endif
 		break;
 
@@ -508,13 +495,7 @@ lockinit(lkp, prio, wmesg, timo, flags)
 	lkp->lk_lockholder = LK_NOPROC;
 	lkp->lk_newlock = NULL;
 #ifdef DEBUG_LOCKS
-	lkp->lk_filename = "none";
-	lkp->lk_lockername = "never exclusive locked";
-	lkp->lk_lineno = 0;
-	lkp->lk_slockholder = LK_NOPROC;
-	lkp->lk_sfilename = "none";
-	lkp->lk_slockername = "never share locked";
-	lkp->lk_slineno = 0;
+	stack_zero(&lkp->stack);
 #endif
 }