> From: "Theo de Raadt" <dera...@openbsd.org>
> Date: Sun, 03 Mar 2024 08:20:33 -0700
>
> It almost feels as if libc.so equivelancy should be closer to
> _dl_find_shlib(),
>
> (in particular, meaning searchpath[0] in _dl_find_shlib() coming
> from lpath in _dl_load_shlib()
>
> Is testing for this in loader.c not the right place, and that
> code should be moved to a deeper place, reached by more variations?
Yes, the diff below would make more sense. Anyway, probably something
to do after the next release?
> The thing that would break is if someone dlopen() of
> "libc.so.not-a-system-library", and that is a real .so but not a real
> full libc; imagine it just contains 1 stub function which isn't a
> system call. it would now fail to load that stub function. So maybe
> it is better if we force the applications to request "libc.so".
Index: libexec/ld.so/library_subr.c
===================================================================
RCS file: /cvs/src/libexec/ld.so/library_subr.c,v
retrieving revision 1.55
diff -u -p -r1.55 library_subr.c
--- libexec/ld.so/library_subr.c 27 Apr 2023 12:27:56 -0000 1.55
+++ libexec/ld.so/library_subr.c 3 Mar 2024 16:44:33 -0000
@@ -321,6 +321,11 @@ _dl_load_shlib(const char *libname, elf_
try_any_minor = 0;
ignore_hints = 0;
+ if (_dl_strncmp(libname, "libc.so.", 8) == 0) {
+ if (_dl_libcname)
+ libname = _dl_libcname;
+ }
+
if (_dl_strchr(libname, '/')) {
char *paths[2];
char *lpath, *lname;
Index: libexec/ld.so/loader.c
===================================================================
RCS file: /cvs/src/libexec/ld.so/loader.c,v
retrieving revision 1.223
diff -u -p -r1.223 loader.c
--- libexec/ld.so/loader.c 22 Jan 2024 02:08:31 -0000 1.223
+++ libexec/ld.so/loader.c 3 Mar 2024 16:44:33 -0000
@@ -406,10 +406,6 @@ _dl_load_dep_libs(elf_object_t *object,
liblist[randomlist[loop]].dynp->d_un.d_val;
DL_DEB(("loading: %s required by %s\n", libname,
dynobj->load_name));
- if (_dl_strncmp(libname, "libc.so.", 8) == 0) {
- if (_dl_libcname)
- libname = _dl_libcname;
- }
depobj = _dl_load_shlib(libname, dynobj,
OBJTYPE_LIB, depflags, nodelete);
if (depobj == 0) {
Index: libexec/ld.so/resolve.h
===================================================================
RCS file: /cvs/src/libexec/ld.so/resolve.h,v
retrieving revision 1.107
diff -u -p -r1.107 resolve.h
--- libexec/ld.so/resolve.h 16 Jan 2024 19:07:31 -0000 1.107
+++ libexec/ld.so/resolve.h 3 Mar 2024 16:44:33 -0000
@@ -376,6 +376,7 @@ extern char **_dl_libpath;
extern int _dl_bindnow;
extern int _dl_traceld;
extern int _dl_debug;
+extern const char *_dl_libcname;
extern char *_dl_preload;
extern char *_dl_tracefmt1;
