svn commit: r362251 - head/libexec/rtld-elf

[Konstantin Belousov]

Author: kib
Date: Tue Jun 16 21:29:02 2020
New Revision: 362251
URL: https://svnweb.freebsd.org/changeset/base/362251

Log:
  rtld: Allow to load ET_DYN && DF_1_PIE when tracing.
  
  This makes old ldd to still work on newer tagged PIE binaries.
  
  Also move debug line for hashes before both decisions to not load are
  done, so that the end of digest_dynamic() processing and reason to not
  load or load is seen in debug trace.
  
  Noted by:	jhb
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/libexec/rtld-elf/rtld.c

Modified: head/libexec/rtld-elf/rtld.c
==============================================================================
--- head/libexec/rtld-elf/rtld.c	Tue Jun 16 21:25:58 2020	(r362250)
+++ head/libexec/rtld-elf/rtld.c	Tue Jun 16 21:29:02 2020	(r362251)
@@ -2612,12 +2612,13 @@ do_load_object(int fd, const char *name, char *path, s
     obj->path = path;
     if (!digest_dynamic(obj, 0))
 	goto errp;
-    if (obj->z_pie) {
+    dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path,
+	obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount);
+    if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) {
+	dbg("refusing to load PIE executable \"%s\"", obj->path);
 	_rtld_error("Cannot load PIE binary %s as DSO", obj->path);
 	goto errp;
     }
-    dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path,
-	obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount);
     if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
       RTLD_LO_DLOPEN) {
 	dbg("refusing to load non-loadable \"%s\"", obj->path);