svn commit: r367905 - head/cddl/contrib/opensolaris/common/ctf

[Jonathan T. Looney]

Author: jtl
Date: Fri Nov 20 17:26:02 2020
New Revision: 367905
URL: https://svnweb.freebsd.org/changeset/base/367905

Log:
  When copying types from one CTF container to another, ensure that we
  encode 0-length (i.e. "") structure and union member names as offset 0.
  This ensures that we don't confuse other parts of the CTF code which
  expect this encoding.
  
  This resolves a Dtrace error resolving members of anonymous structs/unions
  within the (struct mbuf) type which some users were seeing after r366908.
  
  While here, update the code in ctf_add_generic() to encode 0-length type
  names as offset 0.
  
  Reviewed by:	markj
  MFC after:	2 weeks
  Sponsored by:	Netflix
  Differential Revision:	https://reviews.freebsd.org/D27246

Modified:
  head/cddl/contrib/opensolaris/common/ctf/ctf_create.c

Modified: head/cddl/contrib/opensolaris/common/ctf/ctf_create.c
==============================================================================
--- head/cddl/contrib/opensolaris/common/ctf/ctf_create.c	Fri Nov 20 17:13:13 2020	(r367904)
+++ head/cddl/contrib/opensolaris/common/ctf/ctf_create.c	Fri Nov 20 17:26:02 2020	(r367905)
@@ -615,7 +615,7 @@ ctf_add_generic(ctf_file_t *fp, uint_t flag, const cha
 	if ((dtd = ctf_alloc(sizeof (ctf_dtdef_t))) == NULL)
 		return (ctf_set_errno(fp, EAGAIN));
 
-	if (name != NULL && (s = ctf_strdup(name)) == NULL) {
+	if (name != NULL && *name != '\0' && (s = ctf_strdup(name)) == NULL) {
 		ctf_free(dtd, sizeof (ctf_dtdef_t));
 		return (ctf_set_errno(fp, EAGAIN));
 	}
@@ -1217,7 +1217,7 @@ membadd(const char *name, ctf_id_t type, ulong_t offse
 	if ((dmd = ctf_alloc(sizeof (ctf_dmdef_t))) == NULL)
 		return (ctf_set_errno(ctb->ctb_file, EAGAIN));
 
-	if (name != NULL && (s = ctf_strdup(name)) == NULL) {
+	if (name != NULL && *name != '\0' && (s = ctf_strdup(name)) == NULL) {
 		ctf_free(dmd, sizeof (ctf_dmdef_t));
 		return (ctf_set_errno(ctb->ctb_file, EAGAIN));
 	}