From 19ec16208eafdd68268f64600376a8fe6b5ff4d2 Mon Sep 17 00:00:00 2001
From: markj <markj@FreeBSD.org>
Date: Sat, 22 Feb 2014 01:41:45 +0000
Subject: Print a backtrace if the SDT(9) stub gets called so that there's at
 least some hope of figuring out how it happened.

Suggested by:	rstone
MFC after:	1 week
---
 sys/kern/kern_sdt.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sys/kern/kern_sdt.c b/sys/kern/kern_sdt.c
index 845d95b..5191a88 100644
--- a/sys/kern/kern_sdt.c
+++ b/sys/kern/kern_sdt.c
@@ -27,6 +27,7 @@
 
 #include <sys/param.h>
 #include <sys/systm.h>
+#include <sys/kdb.h>
 #include <sys/sdt.h>
 
 SDT_PROVIDER_DEFINE(sdt);
@@ -47,5 +48,6 @@ sdt_probe_stub(uint32_t id, uintptr_t arg0, uintptr_t arg1,
     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4)
 {
 
-	printf("sdt_probe_stub: Why did this get called?\n");
+	printf("sdt_probe_stub: unexpectedly called\n");
+	kdb_backtrace();
 }
-- 
cgit v1.1