svn commit: r288363 - head/sys/cddl/dev/sdt

[Andriy Gapon]

Author: avg
Date: Tue Sep 29 12:02:23 2015
New Revision: 288363
URL: https://svnweb.freebsd.org/changeset/base/288363

Log:
  std: it is important that func name is never an empty string
  
  otherwise DTRACE_ANCHORED() returns false and that makes stack()
  insert a bogus frame at the top.
  For example:
  dtrace -n 'test:dtrace_test::sdttest { stack(); }
  
  This change is not really a solution, but just a work-around.
  The real solution is to record the probe's call site and to use
  that for resolving a function name.
  
  PR:		195222
  MFC after:	22 days

Modified:
  head/sys/cddl/dev/sdt/sdt.c

Modified: head/sys/cddl/dev/sdt/sdt.c
==============================================================================
--- head/sys/cddl/dev/sdt/sdt.c	Tue Sep 29 11:58:21 2015	(r288362)
+++ head/sys/cddl/dev/sdt/sdt.c	Tue Sep 29 12:02:23 2015	(r288363)
@@ -168,6 +168,8 @@ sdt_create_probe(struct sdt_probe *probe
 	 * in the C compiler, so we have to respect const vs non-const.
 	 */
 	strlcpy(func, probe->func, sizeof(func));
+	if (func[0] == '\0')
+		strcpy(func, "none");
 
 	from = probe->name;
 	to = name;