svn commit: r262325 - head/sys/kern

[Mark Johnston]

Author: markj
Date: Sat Feb 22 01:41:45 2014
New Revision: 262325
URL: http://svnweb.freebsd.org/changeset/base/262325

Log:
  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

Modified:
  head/sys/kern/kern_sdt.c

Modified: head/sys/kern/kern_sdt.c
==============================================================================
--- head/sys/kern/kern_sdt.c	Sat Feb 22 01:19:47 2014	(r262324)
+++ head/sys/kern/kern_sdt.c	Sat Feb 22 01:41:45 2014	(r262325)
@@ -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 ar
     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();
 }