It can be used to speed up the libgcc unwinder, and the internal
_dl_find_dso_for_object function (which is used for caller
identification in dlopen and related functions, and in dladdr).
_dl_find_object is in the internal namespace due to bug 28503.
If libgcc switches to _dl_find_object, this namespace issue will
be fixed. It is located in libc for two reasons: it is necessary
to forward the call to the static libc after static dlopen, and
there is a link ordering issue with -static-libgcc and libgcc_eh.a
because libc.so is not a linker script that includes ld.so in the
glibc build tree (so that GCC's internal -lc after libgcc_eh.a does
not pick up ld.so).
It is necessary to do the i386 customization in the
sysdeps/x86/bits/dl_find_object.h header shared with x86-64 because
otherwise, multilib installations are broken.
The implementation uses software transactional memory, as suggested
by Torvald Riegel. Two copies of the supporting data structures are
used, also achieving full async-signal-safety.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The vDSO is is listed in the link_map chain, but is never the subject of
an la_objopen call. A new internal flag __RTLD_VDSO is added that
acts as __RTLD_OPENEXEC to allocate the required 'struct auditstate'
extra space for the 'struct link_map'.
The return value from the callback is currently ignored, since there
is no PLT call involved by glibc when using the vDSO, neither the vDSO
are exported directly.
Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
They are no longer needed after everything has been moved into
libc. The _dl_vsym test has to be removed because the symbol
cannot be used outside libc anymore.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Consolidate all hooks structures into a single one. There are
no static dlopen ABI concerns because glibc 2.34 already comes
with substantial ABI-incompatible changes in this area. (Static
dlopen requires the exact same dynamic glibc version that was used
for static linking.)
The new approach uses a pointer to the hooks structure into
_rtld_global_ro and initalizes it in __rtld_static_init. This avoids
a back-and-forth with various callback functions.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This commit removes the ELF constructor and internal variables from
dlfcn/dlfcn.c. The file now serves the same purpose as
nptl/libpthread-compat.c, so it is renamed to dlfcn/libdl-compat.c.
The use of libdl-shared-only-routines ensures that libdl.a is empty.
This commit adjusts the test suite not to use $(libdl). The libdl.so
symbolic link is no longer installed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The symbol was moved using scripts/move-symbol-to-libc.py.
In elf/Makefile, remove the $(libdl) dependency from testobj1.so
because it the unused libdl DSO now causes elf/tst-unused-deps to
fail.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The symbol was moved using scripts/move-symbol-to-libc.py.
There is a minor functionality enhancement: dlerror now sets
errno if it was set as part of the exception. (This is the result
of using %m in asprintf, to avoid the strerror PLT call.) The
previous errno value upon function return was unpredictable.
Documenting this as a feature is premature; we need to make sure
that the error codes are meaningful when they are set by the dynamic
loader.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Calling free directly may end up freeing a pointer allocated by the
dynamic loader using malloc from libc.so in the base namespace using
the allocator from libc.so in a secondary namespace, which results in
crashes.
This commit redirects the free call through GLRO and the dynamic
linker, to reach the correct namespace. It also cleans up the dlerror
handling along the way, so that pthread_setspecific is no longer
needed (which avoids triggering bug 24774).
this means that *always* libnsl is only built as shared library for
backward compatibility and the NSS modules libnss_nis and libnss_nisplus
are not built at all, libnsl's headers aren't installed.
This compatibility is kept only for architectures and ABIs that have
been added in or before version 2.28.
Replacement implementations based on TIRPC, which additionally support
IPv6, are available from <https://github.com/thkukuk/>.
This change does not affect libnss_compat which does not depended
on libnsl since 2.27 and thus can be used without NIS.
libnsl code depends on Sun RPC, e.g. on --enable-obsolete-rpc (installed
libnsl headers use installed Sun RPC headers), which will be removed in
the following commit.
The __libc_freeres framework does not extend to non-libc.so objects.
This causes problems in general for valgrind and mtrace detecting
unfreed objects in both libdl.so and libpthread.so. This change is
a pre-requisite to properly moving the malloc hooks out of malloc
since such a move now requires precise accounting of all allocated
data before destructors are run.
This commit adds a proper hook in libc.so.6 for both libdl.so and
for libpthread.so, this ensures that shm-directory.c which uses
freeit () to free memory is called properly. We also remove the
nptl_freeres hook and fall back to using weak-ref-and-check idiom
for a loaded libpthread.so, thus making this process similar for
all DSOs.
Lastly we follow best practice and use explicit free calls for
both libdl.so and libpthread.so instead of the generic hook process
which has undefined order.
Tested on x86_64 with no regressions.
Signed-off-by: DJ Delorie <dj@redhat.com>
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
Prevent random runtime crashes due to missing symbols caused by mixed
libnss_* versions.
[BZ #22766]
* include/dlfcn.h [__libc_dl_open]: Replace RTLD_LAZY with RTLD_NOW.
* sysdeps/gnu/unwind-resume.c (__lib_gcc_s_init): Replace
__libc_dlopen_mode() using RTLD_NOW with __libc_dlopen.
* sysdeps/nptl/unwind-forcedunwind.c: Likewise.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This commit adds a new _dl_open_hook entry for dlvsym and implements the
function using the existing dl_lookup_symbol_x function supplied by the
dynamic loader.
A new hook variable, _dl_open_hook2, is introduced, which should make
this change suitable for backporting: For old statically linked
binaries, __libc_dlvsym will always return NULL.
Since _dl_catch_error is only used internally in ld.so, it should be
declared in sysdeps/generic/ldsodefs.h, not include/dlfcn.h and it can
be made hidden.
[BZ #19122]
* include/dlfcn.h (_dl_catch_error): Moved to ...
* sysdeps/generic/ldsodefs.h (_dl_catch_error): Add
attribute_hidden.
https://sourceware.org/bugzilla/show_bug.cgi?id=17833
I've a shared library that contains both undefined and unique symbols.
Then I try to call the following sequence of dlopen:
1. dlopen("./libfoo.so", RTLD_NOW)
2. dlopen("./libfoo.so", RTLD_LAZY | RTLD_GLOBAL)
First dlopen call terminates with error because of undefined symbols,
but STB_GNU_UNIQUE ones set DF_1_NODELETE flag and hence block library
in the memory.
The library goes into inconsistent state as several structures remain
uninitialized. For instance, relocations for GOT table were not performed.
By the time of second dlopen call this library looks like as it would be
fully initialized but this is not true: any call through incorrect GOT
table leads to segmentation fault. On some systems this inconsistency
triggers assertions in the dynamic linker.
This patch adds a parameter to _dl_close_worker to implement forced object
deletion in case of dlopen() failure:
1. Clears DF_1_NODELETE bit if forced, to allow library to be removed from
memory.
2. For each unique symbol that is defined in this object clears
appropriate entry in _ns_unique_sym_table.
[BZ #17833]
* elf/Makefile (tests): Add tst-nodelete.
(modules-names): Add tst-nodelete-uniquemod.
(tst-nodelete-uniquemod.so-no-z-defs): New.
(tst-nodelete-rtldmod.so-no-z-defs): Likewise.
(tst-nodelete-zmod.so-no-z-defs): Likewise.
($(objpfx)tst-nodelete): Likewise.
($(objpfx)tst-nodelete.out): Likewise.
(LDFLAGS-tst-nodelete): Likewise.
(LDFLAGS-tst-nodelete-zmod.so): Likewise.
* elf/dl-close.c (_dl_close_worker): Add a parameter to
implement forced object deletion.
(_dl_close): Pass false to _dl_close_worker.
* elf/dl-open.c (_dl_open): Pass true to _dl_close_worker.
* elf/tst-nodelete.cc: New file.
* elf/tst-nodeletelib.cc: Likewise.
* elf/tst-znodeletelib.cc: Likewise.
* include/dlfcn.h (_dl_close_worker): Add a new parameter.
smaller scopes.
* elf/dl-dst.h (DL_DST_REQ_STATIC): Add l as macro argument.
(DL_DST_REQUIRED): Adjust user.
* include/dlfcn.h (struct link_map): New forward decl.
* inet/getnameinfo.c: Include stddef.h.
(getnameinfo): Use offsetof.
* time/tst-mktime2.c (do_test): Don't rely on signed wrap.
* stdio-common/vfprintf.c (_itoa): Undef before redefining.
* string/strerror_l.c: Include stdlib.h.
real malloc in the catch object.
(_dl_catch_error): Forward information about malloc use to caller
in new parameter.
(_dl_out_of_memory): Make static.
* elf/dl-deps.c: Adjust callers of _dl_catch_error.
* elf/dl-libc.c: Likewise.
* elf/dl-open.c: Likewise.
* elf/rtld.c: Likewise.
Add new --audit option.
* sysdeps/generic/ldsodefs.h: Remove _dl_out_of_memory declaration.
(rtld_global_ro._dl_signal_error): Add new parameter.
* include/dlfcn.h (_dl_catch_error): Add new parameter.
* dlfcn/dlfcn.c (_dlerror_run): Pass additional parameter to
_dl_catch_error. Only free if the returned newly value says so.
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>
Update.
* elf/dl-load.c (_dl_map_object): If __RTLD_CALLMAP flag is set,
reset loader before the actual loading.
* elf/dl-open.c (dl_open_worker): If file name contains no path
element determine map of caller. Pass caller map in this case to
_dl_map_object. Set __RTLD_CALLMAP in mode.
* include/dlfcn.h (__RTLD_CALLMAP): Define. [BZ #116]
Patch by Greg Wolodkin <greg@mathworks.com>.
* include/dlfcn.h (__RTLD_OPENEXEC): Define.
* elf/dl-load.c (_dl_map_object_from_fd): Don't allow loading
executables unless __RTLD_OPENEXEC flag is present.
* elf/rtld.c (dl_main): Pass __RTLD_OPENEXEC flag to
_dl_map_object when loading the executable.
reverse lookup format for IPv6 addresses is using bitstring and
* resolv/ns_name.c: Implement encoding and decoding bitstring in
2001-09-20 H.J. Lu <hjl@gnu.org>
* include/dlfcn.h (__RTLD_SPROF): New definiton.
* elf/dl-open.c (dl_open_worker): Return immediately after loading
for __RTLD_SPROF.
* elf/sprof.c (main): Default to the filename if soname doesn't exist.
(load_shobj): Call dlopen with `RTLD_LAZY | __RTLD_SPROF.
2001-09-20 H.J. Lu <hjl@gnu.org>
* elf/dl-profile.c (_dl_mcount): Use old *narcsp value for newarc,
don't add 1.
2001-09-22 Ulrich Drepper <drepper@redhat.com>
* nss/getent.c: Accept -s parameter to overwrite rules in
nsswitch.conf. Patch by Nalin Dahyabhai <nalin@redhat.com>.
* nss/nss_files/files-network.c (LINE_PARSER): Pad addr string
with as many ".0" as necessary to form a complete address
inet_network understands.
* nss/getent.c: Various cleanups. Use simpler and fewer function
calls.
2001-09-20 Martin Schwidefsky <schwidefsky@de.ibm.com>
* sysdeps/s390/s390-32/bits/setjmp.h: Correct pointer comparison in
_JMPBUF_UNWINDS.
* sysdeps/s390/s390-64/bits/setjmp.h: Likewise.
2001-09-22 Ulrich Drepper <drepper@redhat.com>
* iconvdata/Makefile: Add rules to build and distribute IBM1160 and
IBM1161.
* iconvdata/gconv-modules: Add entries for IBM1160 and IBM1161.
* iconvdata/ibm1160.c: New file.
* iconvdata/ibm1160.h: New file.
* iconvdata/ibm1161.c: New file.
* iconvdata/ibm1161.h: New file.
2001-09-19 Jakub Jelinek <jakub@redhat.com>
* sysdeps/alpha/dl-machine.h (elf_machine_load_address): Compute the
difference between base address and first PT_LOAD's virtual address,
not the base address.
2001-09-11 Tom Rix <trix@redhat.com>
* sysdeps/unix/sysv/aix/init-first.c (init): Use USE_NONONPTION_FLAG
ifdef for __getopt_clean_environment.
* sysdeps/unix/sysv/aix/libc-start.c: Add real implementation.
* sysdeps/unix/sysv/linux/x86_64/Dist: New file.
* sysdeps/x86_64/Dist: New file.
* sysdeps/x86_64/soft-fp/Dist: New file.
