[src/trunk]: src/libexec/ld.elf_so If dlopen of the dynamic linker is request...

[skrll <skrll%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4fabc2efb070
branches:  trunk
changeset: 791473:4fabc2efb070
user:      skrll <skrll%NetBSD.org@localhost>
date:      Wed Nov 20 07:18:23 2013 +0000

description:
If dlopen of the dynamic linker is requested, e.g. by rump in
rumpuser_dl_bootstrap, then return &_rtld_objself as the handle and do
not create a duplicate mapping.

The handle is mostly useless as _rtld_objself doesn't appear on
_rtld_objlist.

This fixes a problem on earm platforms where ld.elf_so (currently) has
an init_array section.  Calling this caused binaries to segv.

diffstat:

 libexec/ld.elf_so/load.c |  11 +++++++++--
 libexec/ld.elf_so/rtld.c |   8 +++++---
 2 files changed, 14 insertions(+), 5 deletions(-)

diffs (62 lines):

diff -r a255e8b57d74 -r 4fabc2efb070 libexec/ld.elf_so/load.c
--- a/libexec/ld.elf_so/load.c  Tue Nov 19 22:41:43 2013 +0000
+++ b/libexec/ld.elf_so/load.c  Wed Nov 20 07:18:23 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: load.c,v 1.45 2013/05/09 15:37:58 christos Exp $        */
+/*     $NetBSD: load.c,v 1.46 2013/11/20 07:18:23 skrll Exp $   */
 
 /*
  * Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: load.c,v 1.45 2013/05/09 15:37:58 christos Exp $");
+__RCSID("$NetBSD: load.c,v 1.46 2013/11/20 07:18:23 skrll Exp $");
 #endif /* not lint */
 
 #include <err.h>
@@ -146,6 +146,13 @@
                }
        }
 
+#ifdef RTLD_LOADER
+       if (pathlen == _rtld_objself.pathlen &&
+           strcmp(_rtld_objself.path, filepath) == 0) {
+               return &_rtld_objself;
+       }
+#endif
+
        if (obj == NULL) { /* First use of this object, so we must map it in */
                obj = _rtld_map_object(filepath, fd, &sb);
                (void)close(fd);
diff -r a255e8b57d74 -r 4fabc2efb070 libexec/ld.elf_so/rtld.c
--- a/libexec/ld.elf_so/rtld.c  Tue Nov 19 22:41:43 2013 +0000
+++ b/libexec/ld.elf_so/rtld.c  Wed Nov 20 07:18:23 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtld.c,v 1.170 2013/10/19 17:19:30 christos Exp $       */
+/*     $NetBSD: rtld.c,v 1.171 2013/11/20 07:18:23 skrll Exp $  */
 
 /*
  * Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
 
 #include <sys/cdefs.h>
 #ifndef lint
-__RCSID("$NetBSD: rtld.c,v 1.170 2013/10/19 17:19:30 christos Exp $");
+__RCSID("$NetBSD: rtld.c,v 1.171 2013/11/20 07:18:23 skrll Exp $");
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -636,8 +636,10 @@
         * one is being used.
         */
        if (_rtld_objmain->interp != NULL &&
-           strcmp(_rtld_objmain->interp, _rtld_objself.path) != 0)
+           strcmp(_rtld_objmain->interp, _rtld_objself.path) != 0) {
                _rtld_objself.path = xstrdup(_rtld_objmain->interp);
+               _rtld_objself.pathlen = strlen(_rtld_objself.path);
+       }
        dbg(("actual dynamic linker is %s", _rtld_objself.path));
 
        _rtld_digest_dynamic(execname, _rtld_objmain);