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-rw-r--r--sysdeps/generic/ldsodefs.h9
-rw-r--r--sysdeps/pthread/Makefile10
-rw-r--r--sysdeps/pthread/tst-create1.c119
-rw-r--r--sysdeps/pthread/tst-create1mod.c41
4 files changed, 176 insertions, 3 deletions
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index d49529da0d..9ec1511bb0 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -369,6 +369,13 @@ struct rtld_global
list of loaded objects while an object is added to or removed
from that list. */
__rtld_lock_define_recursive (EXTERN, _dl_load_write_lock)
+ /* This lock protects global and module specific TLS related data.
+ E.g. it is held in dlopen and dlclose when GL(dl_tls_generation),
+ GL(dl_tls_max_dtv_idx) or GL(dl_tls_dtv_slotinfo_list) are
+ accessed and when TLS related relocations are processed for a
+ module. It was introduced to keep pthread_create accessing TLS
+ state that is being set up. */
+ __rtld_lock_define_recursive (EXTERN, _dl_load_tls_lock)
/* Incremented whenever something may have been added to dl_loaded. */
EXTERN unsigned long long _dl_load_adds;
@@ -1268,7 +1275,7 @@ extern int _dl_scope_free (void *) attribute_hidden;
/* Add module to slot information data. If DO_ADD is false, only the
required memory is allocated. Must be called with GL
- (dl_load_lock) acquired. If the function has already been called
+ (dl_load_tls_lock) acquired. If the function has already been called
for the link map L with !do_add, then this function will not raise
an exception, otherwise it is possible that it encounters a memory
allocation failure. */
diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile
index 0af9c59b42..df8943f486 100644
--- a/sysdeps/pthread/Makefile
+++ b/sysdeps/pthread/Makefile
@@ -152,15 +152,17 @@ tests += tst-cancelx2 tst-cancelx3 tst-cancelx6 tst-cancelx8 tst-cancelx9 \
tst-cleanupx0 tst-cleanupx1 tst-cleanupx2 tst-cleanupx3
ifeq ($(build-shared),yes)
-tests += tst-atfork2 tst-pt-tls4 tst-_res1 tst-fini1
+tests += tst-atfork2 tst-pt-tls4 tst-_res1 tst-fini1 tst-create1
tests-nolibpthread += tst-fini1
endif
modules-names += tst-atfork2mod tst-tls4moda tst-tls4modb \
- tst-_res1mod1 tst-_res1mod2 tst-fini1mod
+ tst-_res1mod1 tst-_res1mod2 tst-fini1mod \
+ tst-create1mod
test-modules = $(addprefix $(objpfx),$(addsuffix .so,$(modules-names)))
tst-atfork2mod.so-no-z-defs = yes
+tst-create1mod.so-no-z-defs = yes
ifeq ($(build-shared),yes)
# Build all the modules even when not actually running test programs.
@@ -279,4 +281,8 @@ LDFLAGS-tst-join7mod.so = -Wl,-soname,tst-join7mod.so
CFLAGS-tst-unwind-thread.c += -funwind-tables
+LDFLAGS-tst-create1 = -Wl,-export-dynamic
+$(objpfx)tst-create1: $(shared-thread-library)
+$(objpfx)tst-create1.out: $(objpfx)tst-create1mod.so
+
endif
diff --git a/sysdeps/pthread/tst-create1.c b/sysdeps/pthread/tst-create1.c
new file mode 100644
index 0000000000..932586c309
--- /dev/null
+++ b/sysdeps/pthread/tst-create1.c
@@ -0,0 +1,119 @@
+/* Verify that pthread_create does not deadlock when ctors take locks.
+ Copyright (C) 2021 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <support/xdlfcn.h>
+#include <support/xthread.h>
+
+/*
+Check if ctor and pthread_create deadlocks in
+
+thread 1: dlopen -> ctor -> lock(user_lock)
+thread 2: lock(user_lock) -> pthread_create
+
+or in
+
+thread 1: dlclose -> dtor -> lock(user_lock)
+thread 2: lock(user_lock) -> pthread_create
+*/
+
+static pthread_barrier_t bar_ctor;
+static pthread_barrier_t bar_dtor;
+static pthread_mutex_t user_lock = PTHREAD_MUTEX_INITIALIZER;
+
+void
+ctor (void)
+{
+ xpthread_barrier_wait (&bar_ctor);
+ dprintf (1, "thread 1: in ctor: started.\n");
+ xpthread_mutex_lock (&user_lock);
+ dprintf (1, "thread 1: in ctor: locked user_lock.\n");
+ xpthread_mutex_unlock (&user_lock);
+ dprintf (1, "thread 1: in ctor: unlocked user_lock.\n");
+ dprintf (1, "thread 1: in ctor: done.\n");
+}
+
+void
+dtor (void)
+{
+ xpthread_barrier_wait (&bar_dtor);
+ dprintf (1, "thread 1: in dtor: started.\n");
+ xpthread_mutex_lock (&user_lock);
+ dprintf (1, "thread 1: in dtor: locked user_lock.\n");
+ xpthread_mutex_unlock (&user_lock);
+ dprintf (1, "thread 1: in dtor: unlocked user_lock.\n");
+ dprintf (1, "thread 1: in dtor: done.\n");
+}
+
+static void *
+thread3 (void *a)
+{
+ dprintf (1, "thread 3: started.\n");
+ dprintf (1, "thread 3: done.\n");
+ return 0;
+}
+
+static void *
+thread2 (void *a)
+{
+ pthread_t t3;
+ dprintf (1, "thread 2: started.\n");
+
+ xpthread_mutex_lock (&user_lock);
+ dprintf (1, "thread 2: locked user_lock.\n");
+ xpthread_barrier_wait (&bar_ctor);
+ t3 = xpthread_create (0, thread3, 0);
+ xpthread_mutex_unlock (&user_lock);
+ dprintf (1, "thread 2: unlocked user_lock.\n");
+ xpthread_join (t3);
+
+ xpthread_mutex_lock (&user_lock);
+ dprintf (1, "thread 2: locked user_lock.\n");
+ xpthread_barrier_wait (&bar_dtor);
+ t3 = xpthread_create (0, thread3, 0);
+ xpthread_mutex_unlock (&user_lock);
+ dprintf (1, "thread 2: unlocked user_lock.\n");
+ xpthread_join (t3);
+
+ dprintf (1, "thread 2: done.\n");
+ return 0;
+}
+
+static void
+thread1 (void)
+{
+ dprintf (1, "thread 1: started.\n");
+ xpthread_barrier_init (&bar_ctor, NULL, 2);
+ xpthread_barrier_init (&bar_dtor, NULL, 2);
+ pthread_t t2 = xpthread_create (0, thread2, 0);
+ void *p = xdlopen ("tst-create1mod.so", RTLD_NOW | RTLD_GLOBAL);
+ dprintf (1, "thread 1: dlopen done.\n");
+ xdlclose (p);
+ dprintf (1, "thread 1: dlclose done.\n");
+ xpthread_join (t2);
+ dprintf (1, "thread 1: done.\n");
+}
+
+static int
+do_test (void)
+{
+ thread1 ();
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/pthread/tst-create1mod.c b/sysdeps/pthread/tst-create1mod.c
new file mode 100644
index 0000000000..62c9006961
--- /dev/null
+++ b/sysdeps/pthread/tst-create1mod.c
@@ -0,0 +1,41 @@
+/* Verify that pthread_create does not deadlock when ctors take locks.
+ Copyright (C) 2021 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+
+/* Require TLS setup for the module. */
+__thread int tlsvar;
+
+void ctor (void);
+void dtor (void);
+
+static void __attribute__ ((constructor))
+do_init (void)
+{
+ dprintf (1, "constructor started: %d.\n", tlsvar++);
+ ctor ();
+ dprintf (1, "constructor done: %d.\n", tlsvar++);
+}
+
+static void __attribute__ ((destructor))
+do_end (void)
+{
+ dprintf (1, "destructor started: %d.\n", tlsvar++);
+ dtor ();
+ dprintf (1, "destructor done: %d.\n", tlsvar++);
+}