Right now, WITNESS just blindly pipes all the output to the

(TOCONS | TOLOG) mask even when called from DDB points.
That breaks several output, where the most notable is textdump output.
Fix this by having configurable callbacks passed to witness_list_locks()
and witness_display_spinlock() for printing out datas.

Reported by:	several broken textdump outputs
Tested by:	Giovanni Trematerra
		<giovanni dot trematerra at gmail dot com>
MFC after:	7 days
X-MFC:		r207922

1 files changed, 18 insertions, 14 deletions

diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c
index 02e2da4..30e971b 100644
--- a/sys/kern/subr_witness.c
+++ b/sys/kern/subr_witness.c
@@ -367,7 +367,8 @@ static int	witness_lock_order_check(struct witness *parent,
 static struct witness_lock_order_data	*witness_lock_order_get(
 					    struct witness *parent,
 					    struct witness *child);
-static void	witness_list_lock(struct lock_instance *instance);
+static void	witness_list_lock(struct lock_instance *instance,
+		    int (*prnt)(const char *fmt, ...));
 static void	witness_setflag(struct lock_object *lock, int flag, int set);
 
 #ifdef KDB
@@ -1597,7 +1598,7 @@ witness_thread_exit(struct thread *td)
 		printf("Thread %p exiting with the following locks held:\n",
 					    td);
 				n++;
-				witness_list_lock(&lle->ll_children[i]);
+				witness_list_lock(&lle->ll_children[i], printf);
 				
 			}
 		panic("Thread %p cannot exit while holding sleeplocks\n", td);
@@ -1646,7 +1647,7 @@ witness_warn(int flags, struct lock_object *lock, const char *fmt, ...)
 				printf(" locks held:\n");
 			}
 			n++;
-			witness_list_lock(lock1);
+			witness_list_lock(lock1, printf);
 		}
 
 	/*
@@ -1677,7 +1678,7 @@ witness_warn(int flags, struct lock_object *lock, const char *fmt, ...)
 		if (flags & WARN_SLEEPOK)
 			printf(" non-sleepable");
 		printf(" locks held:\n");
-		n += witness_list_locks(&lock_list);
+		n += witness_list_locks(&lock_list, printf);
 	} else
 		sched_unpin();
 	if (flags & WARN_PANIC && n)
@@ -2063,16 +2064,17 @@ find_instance(struct lock_list_entry *list, struct lock_object *lock)
 }
 
 static void
-witness_list_lock(struct lock_instance *instance)
+witness_list_lock(struct lock_instance *instance,
+    int (*prnt)(const char *fmt, ...))
 {
 	struct lock_object *lock;
 
 	lock = instance->li_lock;
-	printf("%s %s %s", (instance->li_flags & LI_EXCLUSIVE) != 0 ?
+	prnt("%s %s %s", (instance->li_flags & LI_EXCLUSIVE) != 0 ?
 	    "exclusive" : "shared", LOCK_CLASS(lock)->lc_name, lock->lo_name);
 	if (lock->lo_witness->w_name != lock->lo_name)
-		printf(" (%s)", lock->lo_witness->w_name);
-	printf(" r = %d (%p) locked @ %s:%d\n",
+		prnt(" (%s)", lock->lo_witness->w_name);
+	prnt(" r = %d (%p) locked @ %s:%d\n",
 	    instance->li_flags & LI_RECURSEMASK, lock, instance->li_file,
 	    instance->li_line);
 }
@@ -2101,7 +2103,8 @@ witness_proc_has_locks(struct proc *p)
 #endif
 
 int
-witness_list_locks(struct lock_list_entry **lock_list)
+witness_list_locks(struct lock_list_entry **lock_list,
+    int (*prnt)(const char *fmt, ...))
 {
 	struct lock_list_entry *lle;
 	int i, nheld;
@@ -2109,7 +2112,7 @@ witness_list_locks(struct lock_list_entry **lock_list)
 	nheld = 0;
 	for (lle = *lock_list; lle != NULL; lle = lle->ll_next)
 		for (i = lle->ll_count - 1; i >= 0; i--) {
-			witness_list_lock(&lle->ll_children[i]);
+			witness_list_lock(&lle->ll_children[i], prnt);
 			nheld++;
 		}
 	return (nheld);
@@ -2123,7 +2126,8 @@ witness_list_locks(struct lock_list_entry **lock_list)
  * see when it was last acquired.
  */
 void
-witness_display_spinlock(struct lock_object *lock, struct thread *owner)
+witness_display_spinlock(struct lock_object *lock, struct thread *owner,
+    int (*prnt)(const char *fmt, ...))
 {
 	struct lock_instance *instance;
 	struct pcpu *pc;
@@ -2133,7 +2137,7 @@ witness_display_spinlock(struct lock_object *lock, struct thread *owner)
 	pc = pcpu_find(owner->td_oncpu);
 	instance = find_instance(pc->pc_spinlocks, lock);
 	if (instance != NULL)
-		witness_list_lock(instance);
+		witness_list_lock(instance, prnt);
 }
 
 void
@@ -2306,7 +2310,7 @@ witness_ddb_list(struct thread *td)
 	if (witness_watch < 1)
 		return;
 
-	witness_list_locks(&td->td_sleeplocks);
+	witness_list_locks(&td->td_sleeplocks, db_printf);
 
 	/*
 	 * We only handle spinlocks if td == curthread.  This is somewhat broken
@@ -2322,7 +2326,7 @@ witness_ddb_list(struct thread *td)
 	 * handle threads on other CPU's for now.
 	 */
 	if (td == curthread && PCPU_GET(spinlocks) != NULL)
-		witness_list_locks(PCPU_PTR(spinlocks));
+		witness_list_locks(PCPU_PTR(spinlocks), db_printf);
 }
 
 DB_SHOW_COMMAND(locks, db_witness_list)