svn commit: r363881 - head/sys/sys

[Mateusz Guzik]

Author: mjg
Date: Wed Aug  5 07:28:51 2020
New Revision: 363881
URL: https://svnweb.freebsd.org/changeset/base/363881

Log:
  vfs: prefill nameidata with garbage on debug kernels

Modified:
  head/sys/sys/namei.h

Modified: head/sys/sys/namei.h
==============================================================================
--- head/sys/sys/namei.h	Wed Aug  5 05:58:25 2020	(r363880)
+++ head/sys/sys/namei.h	Wed Aug  5 07:28:51 2020	(r363881)
@@ -196,11 +196,21 @@ int	cache_fplookup(struct nameidata *ndp, enum cache_f
 #define	NDINIT_ATVP(ndp, op, flags, segflg, namep, vp, td)		\
 	NDINIT_ALL(ndp, op, flags, segflg, namep, AT_FDCWD, vp, &cap_no_rights, td)
 
+/*
+ * Note the constant pattern may *hide* bugs.
+ */
+#ifdef INVARIANTS
+#define NDINIT_PREFILL(arg)	memset(arg, 0xff, sizeof(*arg))
+#else
+#define NDINIT_PREFILL(arg)	do { } while (0)
+#endif
+
 #define NDINIT_ALL(ndp, op, flags, segflg, namep, dirfd, startdir, rightsp, td)	\
 do {										\
 	struct nameidata *_ndp = (ndp);						\
 	cap_rights_t *_rightsp = (rightsp);					\
 	MPASS(_rightsp != NULL);						\
+	NDINIT_PREFILL(_ndp);							\
 	_ndp->ni_cnd.cn_nameiop = op;						\
 	_ndp->ni_cnd.cn_flags = flags;						\
 	_ndp->ni_segflg = segflg;						\