The ability to recursively call dlopen is useful for malloc
implementations that wish to load other dynamic modules that
implement reentrant/AS-safe functions to use in their own
implementation.
Given that a user malloc implementation may be called by an
ongoing dlopen to allocate memory the user malloc
implementation interrupts dlopen and if it calls dlopen again
that's a reentrant call.
This patch fixes the issues with the ld.so.cache mapping
and the _r_debug assertion which prevent this from working
as expected.
See:
https://sourceware.org/ml/libc-alpha/2014-12/msg00446.html
In <https://sourceware.org/ml/libc-alpha/2014-01/msg00196.html> I
noted it was necessary to add includes of Makeconfig early in various
subdirectory makefiles for the tests-special variable settings added
by that patch to be conditional on configuration information. No-one
commented on the general question there of whether Makeconfig should
always be included immediately after the definition of subdir.
This patch implements that early inclusion of Makeconfig in each
directory (which is a lot easier than consistent placement of includes
of Rules). Includes are added if needed, or moved up if already
present. Subdirectory "all:" targets are removed, since Makeconfig
provides one.
There is potential for further cleanups I haven't done. Rules and
Makerules have code such as
ifneq "$(findstring env,$(origin headers))" ""
headers :=
endif
to override to empty any value of various variables that came from the
environment. I think there is a case for Makeconfig setting all the
subdirectory variables (other than subdir) to empty to ensure no
outside value is going to take effect if a subdirectory fails to
define a variable. (A list of such variables, possibly out of date
and incomplete, is in manual/maint.texi.) Rules and Makerules would
give errors if Makeconfig hadn't already been included, instead of
including it themselves. The special code to override values coming
from the environment would then be obsolete and could be removed.
Tested x86_64, including that installed binaries are identical before
and after the patch.
* argp/Makefile: Include Makeconfig immediately after defining
subdir.
* assert/Makefile: Likewise.
* benchtests/Makefile: Likewise.
* catgets/Makefile: Likewise.
* conform/Makefile: Likewise.
* crypt/Makefile: Likewise.
* csu/Makefile: Likewise.
(all): Remove target.
* ctype/Makefile: Include Makeconfig immediately after defining
subdir.
* debug/Makefile: Likewise.
* dirent/Makefile: Likewise.
* dlfcn/Makefile: Likewise.
* gmon/Makefile: Likewise.
* gnulib/Makefile: Likewise.
* grp/Makefile: Likewise.
* gshadow/Makefile: Likewise.
* hesiod/Makefile: Likewise.
* hurd/Makefile: Likewise.
(all): Remove target.
* iconvdata/Makefile: Include Makeconfig immediately after
defining subdir.
* inet/Makefile: Likewise.
* intl/Makefile: Likewise.
* io/Makefile: Likewise.
* libio/Makefile: Likewise.
(all): Remove target.
* locale/Makefile: Include Makeconfig immediately after defining
subdir.
* login/Makefile: Likewise.
* mach/Makefile: Likewise.
(all): Remove target.
* malloc/Makefile: Include Makeconfig immediately after defining
subdir.
(all): Remove target.
* manual/Makefile: Include Makeconfig immediately after defining
subdir.
* math/Makefile: Likewise.
* misc/Makefile: Likewise.
* nis/Makefile: Likewise.
* nss/Makefile: Likewise.
* po/Makefile: Likewise.
(all): Remove target.
* posix/Makefile: Include Makeconfig immediately after defining
subdir.
* pwd/Makefile: Likewise.
* resolv/Makefile: Likewise.
* resource/Makefile: Likewise.
* rt/Makefile: Likewise.
* setjmp/Makefile: Likewise.
* shadow/Makefile: Likewise.
* signal/Makefile: Likewise.
* socket/Makefile: Likewise.
* soft-fp/Makefile: Likewise.
* stdio-common/Makefile: Likewise.
* stdlib/Makefile: Likewise.
* streams/Makefile: Likewise.
* string/Makefile: Likewise.
* sunrpc/Makefile: Likewise.
(all): Remove target.
* sysvipc/Makefile: Include Makeconfig immediately after defining
subdir.
* termios/Makefile: Likewise.
* time/Makefile: Likewise.
* timezone/Makefile: Likewise.
(all): Remove target.
* wcsmbs/Makefile: Include Makeconfig immediately after defining
subdir.
* wctype/Makefile: Likewise.
libidn/ChangeLog:
* Makefile: Include Makeconfig immediately after defining subdir.
localedata/ChangeLog:
* Makefile: Include Makeconfig immediately after defining subdir.
(all): Remove target.
nptl/ChangeLog:
* Makefile: Include Makeconfig immediately after defining subdir.
nptl_db/ChangeLog:
* Makefile: Include Makeconfig immediately after defining subdir.
Since the dlopen funcs might invoke a constructor that calls a func
that is in the same compilation unit as the caller, we cannot mark
them as leaf funcs.
Similarly, dlclose might invoke a destructor that calls a func that
is in the same compilation unit as the caller.
URL: https://sourceware.org/bugzilla/show_bug.cgi?id=15897
Reportedy-by: Fabrice Bauzac <libnoon@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This change creates a link map in static executables to serve as the
global search list for dlopen. It fixes a problem with the inability
to access the global symbol object and a crash on an attempt to map a
DSO into the global scope. Some code that has become dead after the
addition of this link map is removed too and test cases are provided.
ld.so.
* malloc/malloc.c (_int_malloc): Use full list insert and not
shortcut which assumes the list is empty for large requests
too.
* elf/tst-addr1.c (do_test): Allow i.dli_sname "_IO_printf".
* stdlib/cxa_atexit.c (__new_exitfn): Rewrite to preserve order in
which the functions were registered.
* dlfcn/Makefile: Add rules to build and run bug-atexit1 and
bug-atexit2.
* dlfcn/bug-atext1.c: New file.
* dlfcn/bug-atext1-lib.c: New file.
* dlfcn/bug-atext2.c: New file.
* dlfcn/bug-atext2-lib.c: New file.
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.
Update.
Add support for namespaces in the dynamic linker.
* dlfcn/Makefile (libdl-routines): Add dlmopen.
* dlfcn/Versions [libdl, GLIBC_2.3.4]: Add dlmopen.
* dlfcn/dlfcn.h: Define Lmid_t, LM_ID_BASE, and LM_ID_NEWLM.
Declare dlmopen. Document RTLD_DI_LMID.
* dlfcn/dlinfo.c: Handle RTLD_DI_LMID.
* dlfcn/dlmopen.c: New file.
* dlfcn/dlopen.c: Pass new parameter to _dl_open.
* dlfcn/dlopenold.c: Likewise.
* elf/dl-addr.c: Adjust for removal of GL(dl_loaded).
* elf/dl-caller.c: Likewise.
* elf/dl-close.c: Likewise.
* elf/dl-conflict.c: Likewise.
* elf/dl-debug.c: Likewise.
* elf/dl-lookup.c: Likewise.
* elf/dl-sym.c: Likewise.
* elf/dl-version.c: Likewise.
* elf/do-lookup.h: Likewise.
* elf/rtld.c: Likewise.
* sysdeps/unix/sysv/linux/i386/dl-librecon.h: Likewise.
* elf/dl-depsc: Likewise. Add new parameter to _dl_map_object.
* elf/dl-fini.c: Call destructors in all namespaces.
* elf/dl-iteratephdr.c: Compute total nloaded. Adjust for removal of
GL(dl_loaded).
* elf/dl-libc.c: Pass new parameter to _dl_open. Adjust for removal
of GL(dl_loaded).
* elf/dl-load.c (_dl_map_object_from_fd): Don't load ld.so a second
time. Reuse the one from the main namespace in all others.
Pass new parameter to _dl_new_object.
Adjust for removal of GL(dl_loaded).
* elf/dl-object.c: Take new parameter. Use it to initialize l_ns.
Adjust for removal of GL(dl_loaded).
* elf/dl-open.c (_dl_open): Take new parameter.
Adjust for removal of GL(dl_loaded).
* elf/dl-support.c: Replace global _dl_loaded etc variables with
_dl_ns variable.
* include/dlfcn.h: Adjust prototype of _dl_open.
Define __LM_ID_CALLER.
* include/link.h: Add l_real, l_ns, and l_direct_opencount elements.
* sysdeps/generic/dl-tls.c: Bump TLS_STATIC_SURPLUS. Since libc is
using TLS we need memory appropriate to the number of namespaces.
* sysdeps/generic/ldsodefs.h (struct rtld_global): Replace _dl_loaded,
_dl_nloaded, _dl_global_scope, _dl_main_searchlist, and
_dl_global_scope_alloc with _dl_ns element. Define DL_NNS.
Adjust prototypes of _dl_map_object and member in rtld_global_ro.
* malloc/malloc.c: Include <dlfcn.h>.
* malloc/arena.c (ptmalloc_init): If libc is not in primary namespace,
never use brk.
* elf/Makefile: Add rules to build and run tst-dlmopen1 and
tst-dlmopen2.
* elf/tst-dlmopen1.c: New file.
* elf/tst-dlmopen1mod.c: New file.
* elf/tst-dlmopen2.c: New file.
* elf/dl-close.c: Improve reference counting by tracking direct loads.
* elf/dl-lookup.c (add_dependency): Likewise.
* elf/dl-open.c (dl_open_worker): Likewise.
* elf/rtld.c (dl_main): Likewise.
2004-09-09 GOTO Masanori <gotom@debian.or.jp>
[BZ #77]
* elf/dl-close.c: Count down l_opencount to check not only for
l_reldeps, but also l_initfini.
2004-10-13 Ulrich Drepper <drepper@redhat.com>
2003-07-21 Ulrich Drepper <drepper@redhat.com>
* Makerules (build-module-helper): Add -z defs unless explicitly said
not to do it.
* dlfcn/Makefile: Define various *-no-z-defs variables for test DSOs
which has undefined symbols.
* elf/Makefile: Likewise.
(common-generated): Add it.
(build-shlib, build-module): Use that instead of generating every time.
($(common-objpfx)libc.so): Depend on it.
(lib%.so rule): Likewise.
(build-module-helper-objlist): Remove %.lds.
* iconvdata/extra-module.mk ($(objpfx)$(mod).so):
Depend on $(common-objpfx)shlib.lds.
* dlfcn/Makefile ($(test-modules)): Likewise.
2003-02-25 Roland McGrath <roland@redhat.com>
* sysdeps/powerpc/powerpc64/dl-machine.h: Support new TLS relocs.
* sysdeps/powerpc/powerpc64/dl-tls.h: New file.
* sysdeps/mach/hurd/chown.c: Use INTDEF for __chown.
* sysdeps/unix/sysv/aix/chown.c: Likewise.
* sysdeps/unix/grantpt.c: Use INTUSE for __chown calls.
* sysdeps/unix/sysv/linux/m68k/chown.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/chown.c: Likewise.
* sysdeps/unix/sysv/linux/i386/chown.c: Use INTDEF2 to define
__chown_internal.
* sysdeps/unix/sysv/linux/s390/s390-32//chown.c: Likewise.
* intl/dcngettext.c [_LIBC]: Use INTUSE for __dcngettext.
* intl/dngettext.c [_LIBC] (DCNGETTEXT): Use INTUSE.
* intl/ngettext.c: Likewise.
* include/sys/socket.h: Declare __connect_internal and define
__connect macro if not NOT_IN_libc.
* sysdeps/mach/hurd/connect.c: Use INTDEF for __connect.
* sysdeps/unix/sysv/aix/connect.c: Likewise.
* sysdeps/unix/sysv/linux/connect.S: Add __connect_internal alias.
* include/unistd.h: Declare __close_internal and define __close macro
if not NOT_IN_libc.
* libio/libioP.h (JUMO0, JUMP1, JUMP2, JUMP3, WJUMP0, WJUMP1, WJUMP2,
WJUMP3): Add extra parenthesis to avoid expanding element names with
macors like __close.
* sysdeps/unix/syscalls.list: Add __close_internal alias.
* include/unistd.h: Declare __dup2_internal and define __dup2 macro
if not NOT_IN_libc.
* sysdeps/mach/hurd/dup2.c: Use INTDEF for __dup2.
* sysdeps/posix/dup2.c: Use INTDEF for __dup2.
* sysdeps/unix/syscalls.list: Add __dup2_internal alias.
* include/unistd.h: Declare __fork_internal and define __fork macro
if not NOT_IN_libc.
* sysdeps/mach/hurd/fork.c: Use INTDEF for __fork.
* sysdeps/unix/sysv/aix/fork.c: Likewise.
* sysdeps/unix/sysv/linux/syscalls.list: Add __fork_internal alias.
* include/stdio_ext.h: Declare __fsetlocking_internal and define
__fsetlocking macro to use it if not NOT_IN_libc.
* libio/__fsetlocking.c: Use INTDEF for __fsetlocking.
* libio/__fbufsize.c: Correct copyright.
* libio/__flbf.c: Likewise.
* libio/__fpending.c: Likewise.
* libio/__fpurge.c: Likewise.
* libio/__freadable.c: Likewise.
* libio/__freading.c: Likewise.
* libio/__fsetlocking.c: Likewise.
* libio/__fwritable.c: Likewise.
* libio/__fwriting.c: Likewise.
* include/stdio.h: Declare __asprintf_internal and define __asprintf
macro to use it if not NOT_IN_libc.
* stdio-common/asprintf.c: Use INTDEF for __asprintf.
* include/mntent.h: Declare __setmntent_internal,
__getmntent_r_internal, __endmntent_internal. Define __setmntent,
__getmntent_r, and __endmntent macros to use these functions if not
NOT_IN_libc.
* misc/mntent_r.c: Use INTDEF for __setmntent, __getmntent_r, and
__endmntent.
* include/math.h: Declare __finite_internal, __finitef_internal, and
__finitel_internal. Redefine isfinite macro if in libc or libm using
these functions.
* sysdeps/generic/s_ldexp.c: Use INTUSE for __finite calls.
* sysdeps/generic/s_ldexpf.c: Use INTUSE for __finitef calls.
* sysdeps/generic/s_ldexpl.c: Use INTUSE for __finitel calls.
* sysdeps/i386/fpu/s_finite.S: Define _internal alias.
* sysdeps/i386/fpu/s_finitef.S: Likewise.
* sysdeps/i386/fpu/s_finitel.S: Likewise.
* sysdeps/ieee754/dbl-64/s_finite.c: Likewise.
* sysdeps/ieee754/flt-32/s_finitef.c: Likewise.
* sysdeps/ieee754/ldbl-128/s_finitel.c: Likewise.
* sysdeps/ieee754/ldbl-96/s_finitel.c: Likewise.
* include/fcntl.h: Declare __fcntl_internal. Define __fcntl macro
to use this function if not NOT_IN_libc.
* libio/iofdopen.c (_IO_fcntl): Use INTUSE.
* sysdeps/generic/fcntl.c: Use INTDEF for __fcntl.
* sysdeps/mach/hurd/fcntl.c: Likewise.
* sysdeps/unix/sysv/aix/fcntl.c: Likewise.
* sysdeps/unix/sysv/linux/i386/fcntl.c: Likewise.
* include/argz.h: Declare __argz_count_internal and
__argz_stringify_internal.
* intl/l10nflist.c [_LIBC]: Use INTUSE for __argz_count and
__argz_stringify.
* string/argz-count.c: Use INTDEF for __argz_count.
* string/argz-stringify.c: Use INTDEF for __argz_stringify.
* include/stdlib.h: Declare __cxa_atexit_internal and define
__cxa_atexit macro if not NOT_IN_libc.
* stdlib/cxa_atexit.c: Use INTDEF for __cxa_atexit.
* dlfcn/Makefile: Define NOT_IN_libc when compiling modcxaatexit.c.
* assert/assert.c: Use INTDEF for __assert_fail.
* assert/__assert.c: Use INTUSE for call to __assert_fail.
* include/assert.h: Declare __assert_fail_internal.
