From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Subject: [PATCH v3 19/37] dlfcn: Failures after dlmopen should not terminate process [BZ #24772]
Date: Tue, 16 Mar 2021 18:30:10 +0100 [thread overview]
Message-ID: <b0c049610de0cb47bfaf2d460d3dd66fa72a8cdb.1615914632.git.fweimer@redhat.com> (raw)
In-Reply-To: <cover.1615914631.git.fweimer@redhat.com>
Commit 9e78f6f6e7134a5f299cc8de77370218f8019237 ("Implement
_dl_catch_error, _dl_signal_error in libc.so [BZ #16628]") has the
side effect that distinct namespaces, as created by dlmopen, now have
separate implementations of the rtld exception mechanism. This means
that the call to _dl_catch_error from libdl in a secondary namespace
does not actually install an exception handler because the
thread-local variable catch_hook in the libc.so copy in the secondary
namespace is distinct from that of the base namepace. As a result, a
dlsym/dlopen/… failure in a secondary namespace terminates the process
with a dynamic linker error because it looks to the exception handler
mechanism as if no handler has been installed.
This commit restores GLRO (dl_catch_error) and uses it to set the
handler in the base namespace.
---
dlfcn/dlerror.c | 6 +++--
elf/Makefile | 8 ++++++-
elf/dl-error-skeleton.c | 12 ++++++++++
elf/rtld.c | 1 +
elf/tst-dlmopen-dlerror-mod.c | 41 +++++++++++++++++++++++++++++++++++
elf/tst-dlmopen-dlerror.c | 37 +++++++++++++++++++++++++++++++
sysdeps/generic/ldsodefs.h | 9 ++++++++
7 files changed, 111 insertions(+), 3 deletions(-)
create mode 100644 elf/tst-dlmopen-dlerror-mod.c
create mode 100644 elf/tst-dlmopen-dlerror.c
diff --git a/dlfcn/dlerror.c b/dlfcn/dlerror.c
index 48b4c25bea..947b7c10c6 100644
--- a/dlfcn/dlerror.c
+++ b/dlfcn/dlerror.c
@@ -167,8 +167,10 @@ _dlerror_run (void (*operate) (void *), void *args)
result->errstring = NULL;
}
- result->errcode = _dl_catch_error (&result->objname, &result->errstring,
- &result->malloced, operate, args);
+ result->errcode = GLRO (dl_catch_error) (&result->objname,
+ &result->errstring,
+ &result->malloced,
+ operate, args);
/* If no error we mark that no error string is available. */
result->returned = result->errstring == NULL;
diff --git a/elf/Makefile b/elf/Makefile
index 936d4cf276..deb76aed99 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -222,7 +222,8 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
tst-audit14 tst-audit15 tst-audit16 \
tst-single_threaded tst-single_threaded-pthread \
tst-tls-ie tst-tls-ie-dlmopen argv0test \
- tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask
+ tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \
+ tst-dlmopen-dlerror
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
@@ -344,6 +345,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
libmarkermod2-1 libmarkermod2-2 \
libmarkermod3-1 libmarkermod3-2 libmarkermod3-3 \
libmarkermod4-1 libmarkermod4-2 libmarkermod4-3 libmarkermod4-4 \
+ tst-ldconfig-ld-mod tst-dlmopen-dlerror-mod \
# Most modules build with _ISOMAC defined, but those filtered out
# depend on internal headers.
@@ -1580,6 +1582,10 @@ $(objpfx)tst-sonamemove-dlopen.out: \
$(objpfx)tst-sonamemove-runmod1.so \
$(objpfx)tst-sonamemove-runmod2.so
+$(objpfx)tst-dlmopen-dlerror: $(libdl)
+$(objpfx)tst-dlmopen-dlerror-mod.so: $(libdl) $(libsupport)
+$(objpfx)tst-dlmopen-dlerror.out: $(objpfx)tst-dlmopen-dlerror-mod.so
+
# Override -z defs, so that we can reference an undefined symbol.
# Force lazy binding for the same reason.
LDFLAGS-tst-latepthreadmod.so = \
diff --git a/elf/dl-error-skeleton.c b/elf/dl-error-skeleton.c
index 2fd62777cf..b699936c6e 100644
--- a/elf/dl-error-skeleton.c
+++ b/elf/dl-error-skeleton.c
@@ -248,4 +248,16 @@ _dl_receive_error (receiver_fct fct, void (*operate) (void *), void *args)
catch_hook = old_catch;
receiver = old_receiver;
}
+
+/* Forwarder used for initializing GLRO (_dl_catch_error). */
+int
+_rtld_catch_error (const char **objname, const char **errstring,
+ bool *mallocedp, void (*operate) (void *),
+ void *args)
+{
+ /* The reference to _dl_catch_error will eventually be relocated to
+ point to the implementation in libc.so. */
+ return _dl_catch_error (objname, errstring, mallocedp, operate, args);
+}
+
#endif /* DL_ERROR_BOOTSTRAP */
diff --git a/elf/rtld.c b/elf/rtld.c
index 94a00e2049..fd02438936 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -368,6 +368,7 @@ struct rtld_global_ro _rtld_global_ro attribute_relro =
._dl_lookup_symbol_x = _dl_lookup_symbol_x,
._dl_open = _dl_open,
._dl_close = _dl_close,
+ ._dl_catch_error = _rtld_catch_error,
._dl_tls_get_addr_soft = _dl_tls_get_addr_soft,
#ifdef HAVE_DL_DISCOVER_OSVERSION
._dl_discover_osversion = _dl_discover_osversion
diff --git a/elf/tst-dlmopen-dlerror-mod.c b/elf/tst-dlmopen-dlerror-mod.c
new file mode 100644
index 0000000000..dcb94320b4
--- /dev/null
+++ b/elf/tst-dlmopen-dlerror-mod.c
@@ -0,0 +1,41 @@
+/* Check that dlfcn errors are reported properly after dlmopen. Test module.
+ Copyright (C) 2019 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <dlfcn.h>
+#include <stddef.h>
+#include <support/check.h>
+
+/* Note: This object is not linked into the main program, so we cannot
+ use delayed test failure reporting via TEST_VERIFY etc., and have
+ to use FAIL_EXIT1 (or something else that calls exit). */
+
+void
+call_dlsym (void)
+{
+ void *ptr = dlsym (NULL, "does not exist");
+ if (ptr != NULL)
+ FAIL_EXIT1 ("dlsym did not fail as expected");
+}
+
+void
+call_dlopen (void)
+{
+ void *handle = dlopen ("tst-dlmopen-dlerror does not exist", RTLD_NOW);
+ if (handle != NULL)
+ FAIL_EXIT1 ("dlopen did not fail as expected");
+}
diff --git a/elf/tst-dlmopen-dlerror.c b/elf/tst-dlmopen-dlerror.c
new file mode 100644
index 0000000000..65638f7f38
--- /dev/null
+++ b/elf/tst-dlmopen-dlerror.c
@@ -0,0 +1,37 @@
+/* Check that dlfcn errors are reported properly after dlmopen.
+ Copyright (C) 2019 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <stddef.h>
+#include <support/check.h>
+#include <support/xdlfcn.h>
+
+static int
+do_test (void)
+{
+ void *handle = xdlmopen (LM_ID_NEWLM, "tst-dlmopen-dlerror-mod.so",
+ RTLD_NOW);
+ void (*call_dlsym) (void) = xdlsym (handle, "call_dlsym");
+ void (*call_dlopen) (void) = xdlsym (handle, "call_dlopen");
+
+ call_dlsym ();
+ call_dlopen ();
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index ea3f7a69d0..b207f229c3 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -662,6 +662,12 @@ struct rtld_global_ro
void *(*_dl_open) (const char *file, int mode, const void *caller_dlopen,
Lmid_t nsid, int argc, char *argv[], char *env[]);
void (*_dl_close) (void *map);
+ /* libdl in a secondary namespace (after dlopen) must use
+ _dl_catch_error from the main namespace, so it has to be
+ exported in some way. */
+ int (*_dl_catch_error) (const char **objname, const char **errstring,
+ bool *mallocedp, void (*operate) (void *),
+ void *args);
void *(*_dl_tls_get_addr_soft) (struct link_map *);
#ifdef HAVE_DL_DISCOVER_OSVERSION
int (*_dl_discover_osversion) (void);
@@ -900,6 +906,9 @@ extern int _dl_catch_error (const char **objname, const char **errstring,
void *args);
libc_hidden_proto (_dl_catch_error)
+/* Used for initializing GLRO (_dl_catch_error). */
+extern __typeof__ (_dl_catch_error) _rtld_catch_error attribute_hidden;
+
/* Call OPERATE (ARGS). If no error occurs, set *EXCEPTION to zero.
Otherwise, store a copy of the raised exception in *EXCEPTION,
which has to be freed by _dl_exception_free. As a special case, if
--
2.29.2
next prev parent reply other threads:[~2021-03-16 17:30 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 17:27 [PATCH v3 00/37] libpthread removal: NPTL forwarders are gone Florian Weimer
2021-03-16 17:27 ` [PATCH v3 01/37] nptl: Move pthread_mutex_consistent into libc Florian Weimer
2021-03-17 11:36 ` Adhemerval Zanella
2021-03-16 17:27 ` [PATCH v3 02/37] nptl: Move __pthread_cleanup_routine " Florian Weimer
2021-03-16 17:27 ` [PATCH v3 03/37] nptl: Move legacy unwinding implementation " Florian Weimer
2021-03-16 17:27 ` [PATCH v3 04/37] nptl: Move legacy cancelation handling into libc as compat symbols Florian Weimer
2021-03-16 17:27 ` [PATCH v3 05/37] nptl: Remove longjmp, siglongjmp from libpthread Florian Weimer
2021-03-17 11:38 ` Adhemerval Zanella
2021-03-16 17:28 ` [PATCH v3 06/37] x86: Restore compile-time check for shadow stack pointer in longjmp Florian Weimer
2021-03-16 17:28 ` [PATCH v3 07/37] nptl: Move __pthread_cleanup_upto into libc Florian Weimer
2021-03-16 17:28 ` [PATCH v3 08/37] nptl: Move pthread_once and __pthread_once " Florian Weimer
2021-03-17 13:30 ` Adhemerval Zanella
2021-03-17 13:37 ` Adhemerval Zanella
2021-03-17 14:45 ` Florian Weimer
2021-03-17 16:39 ` Adhemerval Zanella
2021-03-17 16:56 ` Florian Weimer
2021-03-17 17:22 ` Adhemerval Zanella
2021-03-17 17:43 ` Florian Weimer
2021-03-17 19:09 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 09/37] nptl: Move __pthread_unwind_next " Florian Weimer
2021-03-17 19:42 ` Adhemerval Zanella
2021-03-17 19:54 ` Florian Weimer
2021-03-17 20:16 ` Adhemerval Zanella
2021-03-17 20:33 ` Florian Weimer
2021-03-17 20:44 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 10/37] csu: Move calling main out of __libc_start_main_impl Florian Weimer
2021-03-17 20:45 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 11/37] nptl: Move internal __nptl_nthreads variable into libc Florian Weimer
2021-03-18 12:42 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 12/37] nptl_db: Introduce DB_MAIN_ARRAY_VARIABLE Florian Weimer
2021-03-18 12:43 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 13/37] nptl: Move __pthread_keys global variable into libc Florian Weimer
2021-03-18 12:44 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 14/37] nptl: Move __nptl_deallocate_tsd " Florian Weimer
2021-03-18 12:46 ` Adhemerval Zanella
2021-03-18 17:16 ` Florian Weimer
2021-03-18 17:54 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 15/37] nptl: Move pthread_exit " Florian Weimer
2021-03-18 12:49 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 16/37] nptl: Move pthread_setcancelstate " Florian Weimer
2021-03-18 12:52 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 17/37] nptl: Move pthread_setcanceltype " Florian Weimer
2021-03-18 12:53 ` Adhemerval Zanella
2021-03-16 17:29 ` [PATCH v3 18/37] nptl: Invoke the set_robust_list system call directly in fork Florian Weimer
2021-03-18 12:54 ` Adhemerval Zanella
2021-03-16 17:30 ` Florian Weimer [this message]
2021-03-19 19:56 ` [PATCH v3 19/37] dlfcn: Failures after dlmopen should not terminate process [BZ #24772] Adhemerval Zanella
2021-03-27 16:57 ` Florian Weimer
2021-03-16 17:30 ` [PATCH v3 20/37] dlfcn: dlerror needs to call free from the base namespace [BZ #24773] Florian Weimer
2021-03-23 14:47 ` Adhemerval Zanella
2021-03-16 17:30 ` [PATCH v3 21/37] Remove pthread_key_create-related internals from libc-lock.h Florian Weimer
2021-03-23 16:39 ` Adhemerval Zanella
2021-03-16 17:30 ` [PATCH v3 22/37] elf: Introduce __tls_init_tp for second-phase TCB initialization Florian Weimer
2021-03-23 18:25 ` Adhemerval Zanella
2021-03-16 17:30 ` [PATCH v3 23/37] nptl: Move part of TCB initialization from libpthread to __tls_init_tp Florian Weimer
2021-03-24 13:56 ` Adhemerval Zanella
2021-03-27 17:19 ` Florian Weimer
2021-03-16 17:30 ` [PATCH v3 24/37] nptl: Move pthread_key_create, __pthread_key_create into libc Florian Weimer
2021-03-24 14:09 ` Adhemerval Zanella
2021-03-24 14:32 ` Florian Weimer
2021-03-24 14:42 ` Adhemerval Zanella
2021-03-24 15:08 ` Florian Weimer
2021-03-24 15:46 ` Adhemerval Zanella
2021-03-16 17:30 ` [PATCH v3 25/37] nptl: Move pthread_getspecific, __pthread_getspecific " Florian Weimer
2021-03-24 14:12 ` Adhemerval Zanella
2021-03-24 14:38 ` Florian Weimer
2021-03-24 14:43 ` Adhemerval Zanella
2021-03-16 17:30 ` [PATCH v3 26/37] nptl: Move pthread_setspecific, __pthread_setspecific " Florian Weimer
2021-03-24 14:26 ` Adhemerval Zanella
2021-03-16 17:30 ` [PATCH v3 27/37] nptl: Move pthread_key_delete " Florian Weimer
2021-03-24 14:45 ` Adhemerval Zanella
2021-03-16 17:31 ` [PATCH v3 28/37] nptl: Move rwlock functions with forwarders " Florian Weimer
2021-03-25 19:52 ` Adhemerval Zanella
2021-03-27 21:41 ` Florian Weimer
2021-03-16 17:31 ` [PATCH v3 29/37] nptl: Move the internal thread priority protection symbols " Florian Weimer
2021-03-25 20:21 ` Adhemerval Zanella
2021-03-16 17:31 ` [PATCH v3 30/37] pthread: Introduce __pthread_early_init Florian Weimer
2021-03-25 20:22 ` Adhemerval Zanella
2021-03-16 17:31 ` [PATCH v3 31/37] nptl: Move internal symbol __mutex_aconf into libc Florian Weimer
2021-03-25 20:24 ` Adhemerval Zanella
2021-03-16 17:31 ` [PATCH v3 32/37] nptl: pthread_mutex_lock, pthread_mutex_unock single-threaded optimization Florian Weimer
2021-03-26 18:00 ` Adhemerval Zanella
2021-03-16 17:31 ` [PATCH v3 33/37] x86: Remove low-level lock optimization Florian Weimer
2021-03-25 20:30 ` Adhemerval Zanella
2021-03-16 17:31 ` [PATCH v3 34/37] nptl: Move core mutex functions into libc Florian Weimer
2021-03-25 20:46 ` Adhemerval Zanella
2021-03-16 17:31 ` [PATCH v3 35/37] nptl: Move core condition variable " Florian Weimer
2021-03-26 17:14 ` Adhemerval Zanella
2021-03-16 17:31 ` [PATCH v3 36/37] nptl: Move setxid broadcast implementation " Florian Weimer
2021-03-26 18:15 ` Adhemerval Zanella
2021-04-06 18:41 ` Florian Weimer
2021-04-06 18:54 ` Adhemerval Zanella
2021-04-06 19:23 ` Florian Weimer
2021-04-06 19:40 ` Adhemerval Zanella
2021-03-16 17:31 ` [PATCH v3 37/37] nptl: Remove remnants of the libc/libpthread forwarder interface Florian Weimer
2021-03-26 18:19 ` Adhemerval Zanella
2021-03-18 22:06 ` [PATCH v3 00/37] libpthread removal: NPTL forwarders are gone Florian Weimer
2021-03-26 18:25 ` Adhemerval Zanella
2021-03-31 10:18 ` Florian Weimer
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