GLRO (_rtld_global_ro) is read-only after initialization and can
therefore not be patched at run time, unlike the hook table addresses
and their contents, so this is a desirable hardening feature.
The hooks are only needed if ld.so has not been initialized, and this
happens only after static dlopen (dlmopen uses a single ld.so object
across all namespaces).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2004-10-18 Jakub Jelinek <jakub@redhat.com>
* elf/dl-libc.c (__libc_dlsym_private, __libc_register_dl_open_hook):
New functions.
(__libc_dlopen_mode): Call __libc_register_dl_open_hook and
__libc_register_dlfcn_hook.
* dlfcn/Makefile (routines, elide-routines.os): Set.
Add rules to build and test tststatic2.
* dlfcn/tststatic2.c: New test.
* dlfcn/modstatic2.c: New test module.
* dlfcn/dladdr.c: Call _dlfcn_hook from libdl.so if not NULL.
Define __ prefixed routine in libc.a and in libdl.a just call it.
* dlfcn/dladdr1.c: Likewise.
* dlfcn/dlclose.c: Likewise.
* dlfcn/dlerror.c: Likewise.
* dlfcn/dlinfo.c: Likewise.
* dlfcn/dlmopen.c: Likewise.
* dlfcn/dlopen.c: Likewise.
* dlfcn/dlopenold.c: Likewise.
* dlfcn/dlsym.c: Likewise.
* dlfcn/dlvsym.c: Likewise.
* dlfcn/sdladdr.c: New file.
* dlfcn/sdladdr1.c: New file.
* dlfcn/sdlclose.c: New file.
* dlfcn/sdlerror.c: New file.
* dlfcn/sdlinfo.c: New file.
* dlfcn/sdlopen.c: New file.
* dlfcn/sdlsym.c: New file.
* dlfcn/sdlvsym.c: New file.
* dlfcn/Versions (libdl): Export _dlfcn_hook@GLIBC_PRIVATE.
* include/dlfcn.h (DL_CALLER_DECL, DL_CALLER RETURN_ADDRESS): Define.
(struct dlfcn_hook): New type.
(_dlfcn_hook): New extern decl.
(__dlopen, __dlclose, __dlsym, __dlerror, __dladdr, __dladdr1,
__dlinfo, __dlmopen, __libc_dlsym_private,
__libc_register_dl_open_hook, __libc_register_dlfcn_hook): New
prototypes.
(__dlvsym): Use DL_CALLER_DECL.
* include/libc-symbols.h: Define libdl_hidden_proto and friends.
* malloc/arena.c (_dl_open_hook): Extern decl.
(ptmalloc_init): Don't call _dl_addr when dlopened from statically
linked programs but don't use brk for them either.
2001-07-06 Paul Eggert <eggert@twinsun.com>
* manual/argp.texi: Remove ignored LGPL copyright notice; it's
not appropriate for documentation anyway.
* manual/libc-texinfo.sh: "Library General Public License" ->
"Lesser General Public License".
2001-07-06 Andreas Jaeger <aj@suse.de>
* All files under GPL/LGPL version 2: Place under LGPL version
2.1.
* sysdeps/gnu/Makefile (libdl-routines): Add eval.
1999-07-06 Zack Weinberg <zack@rabi.columbia.edu>
* dlfcn: New directory. Move the following files from elf:
dladdr.c, dlclose.c, dlerror.c, dlfcn.h, dlopen.c,
dlopenold.c, dlsym.c, dlvsym.c.
* dlfcn/Makefile: New file.
* dlfcn/Versions: New file.
* dlfcn/dlsym.c: All ELF-specific code split out to new
function _dl_sym.
* dlfcn/dlvsym.c: All ELF-specific code split out to new
function _dl_vsym.
* elf/dl-sym.c: New file. _dl_sym and _dl_vsym are
implemented here.
* dlfcn/dladdr.c: Remove all references to ELF data structures
or headers.
* dlfcn/dlclose.c: Likewise.
* dlfcn/dlerror.c: Likewise.
* dlfcn/dlopen.c: Likewise.
* dlfcn/dlopenold.c: Likewise.
* Makeconfig (dlfcn): New variable - set to `dlfcn' if elf is
yes, empty otherwise.
(libdl): Set to dlfcn/libdl.so or libdl.a if elf is yes,
depending on build-shared.
(subdirs): Add $(dlfcn).
(rpath-dirs): Add dlfcn.
* elf/Makefile: Remove all references to libdl or its
components, except the ones relating to the test cases.
(routines): Add dl-sym.
* elf/Versions (libc): Add _dl_sym and _dl_vsym for GLIBC_2.2.
(libdl): Delete.
* elf/dl-close.c (_dl_close): Change argument to void *.
* elf/dl-open.c (_dl_open): Change return type to void *.
* elf/eval.c: Removed.
* elf/ldsodefs.h: Move prototypes of _dl_catch_error,
_dlerror_run, _dl_open, _dl_close, _dl_addr, and
_dl_mcount_wrapper_check to include/dlfcn.h. Delete
_CALL_DL_FCT macro.
* include/dlfcn.h: Also prototype _dl_sym and _dl_vsym here.
Include real header from dlfcn directory.
* include/ldsodefs.h: Removed.
* grp/initgroups.c: Use DL_CALL_FCT not _CALL_DL_FCT.
* nss/getXXbyYY_r.c: Likewise.
* nss/getXXent_r.c: Likewise.
* iconv/gconv.c: Likewise. Don't include ldsodefs.h.
* iconv/gconv_db.c: Likewise. Don't include ldsodefs.h.
* iconv/skeleton.c: Don't include ldsodefs.h.
* nss/nsswitch.h: Don't include ldsodefs.h. Include dlfcn.h.
1999-07-07 Ulrich Drepper <drepper@cygnus.com>
