htl: Move thread table to ld.so

The next commit is going to introduce a new implementation of
THREAD_GSCOPE_WAIT which needs to access the list of threads.
Since it must be usable from the dynamic laoder, we have to move
the symbols for the list of threads into the loader.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20210915171110.226187-2-bugaevc@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

9 files changed, 52 insertions, 11 deletions

diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 02bd579..f01b601 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -486,7 +486,16 @@ struct rtld_global
 
   /* Mutex protecting the stack lists.  */
   EXTERN int _dl_stack_cache_lock;
+#else
+  /* The total number of thread IDs currently in use, or on the list of
+     available thread IDs.  */
+  EXTERN int _dl_pthread_num_threads;
+
+  /* Array of __pthread structures and its lock.  */
+  EXTERN struct __pthread **_dl_pthread_threads;
+  __libc_rwlock_define (EXTERN, _dl_pthread_threads_lock)
 #endif
+
 #if !THREAD_GSCOPE_IN_TCB
   EXTERN int _dl_thread_gscope_count;
 #endif
diff --git a/sysdeps/htl/dl-support.c b/sysdeps/htl/dl-support.c
new file mode 100644
index 0000000..7198a3f
--- /dev/null
+++ b/sysdeps/htl/dl-support.c
@@ -0,0 +1,23 @@
+/* Support for dynamic linking code in static libc.
+   Copyright (C) 2007-2021 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 <elf/dl-support.c>
+
+int _dl_pthread_num_threads;
+struct __pthread **_dl_pthread_threads;
+__libc_rwlock_define_initialized (, _dl_pthread_threads_lock)
diff --git a/sysdeps/htl/pt-key-delete.c b/sysdeps/htl/pt-key-delete.c
index 4e77ef7..9f5907b 100644
--- a/sysdeps/htl/pt-key-delete.c
+++ b/sysdeps/htl/pt-key-delete.c
@@ -39,12 +39,12 @@ __pthread_key_delete (pthread_key_t key)
       __pthread_key_destructors[key] = PTHREAD_KEY_INVALID;
       __pthread_key_invalid_count++;
 
-      __pthread_rwlock_rdlock (&__pthread_threads_lock);
-      for (i = 0; i < __pthread_num_threads; ++i)
+      __libc_rwlock_rdlock (GL (dl_pthread_threads_lock));
+      for (i = 0; i < GL (dl_pthread_num_threads); ++i)
 	{
 	  struct __pthread *t;
 
-	  t = __pthread_threads[i];
+	  t = GL (dl_pthread_threads)[i];
 
 	  if (t == NULL)
 	    continue;
@@ -54,7 +54,7 @@ __pthread_key_delete (pthread_key_t key)
 	  if (key < t->thread_specifics_size)
 	    t->thread_specifics[key] = 0;
 	}
-      __pthread_rwlock_unlock (&__pthread_threads_lock);
+      __libc_rwlock_unlock (GL (dl_pthread_threads_lock));
     }
 
   __pthread_mutex_unlock (&__pthread_key_lock);
diff --git a/sysdeps/htl/pthreadP.h b/sysdeps/htl/pthreadP.h
index 3fd7742..8b02bef 100644
--- a/sysdeps/htl/pthreadP.h
+++ b/sysdeps/htl/pthreadP.h
@@ -31,8 +31,6 @@ extern void __pthread_init_static_tls (struct link_map *) attribute_hidden;
 
 /* These represent the interface used by glibc itself.  */
 
-extern struct __pthread **__pthread_threads;
-
 extern int __pthread_mutex_init (pthread_mutex_t *__mutex, const pthread_mutexattr_t *__attr);
 extern int __pthread_mutex_destroy (pthread_mutex_t *__mutex);
 extern int __pthread_mutex_lock (pthread_mutex_t *__mutex);
diff --git a/sysdeps/htl/raise.c b/sysdeps/htl/raise.c
index 5a0f37d..8c17db6 100644
--- a/sysdeps/htl/raise.c
+++ b/sysdeps/htl/raise.c
@@ -17,6 +17,7 @@
    License along with this program.  If not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <ldsodefs.h>
 #include <pthreadP.h>
 #include <signal.h>
 #include <unistd.h>
@@ -24,6 +25,11 @@
 #pragma weak __pthread_kill
 #pragma weak __pthread_self
 #pragma weak __pthread_threads
+
+#ifndef SHARED
+#pragma weak _dl_pthread_threads
+#endif
+
 int
 raise (int signo)
 {
@@ -31,7 +37,7 @@ raise (int signo)
      "the effect of the raise() function shall be equivalent to
      calling: pthread_kill(pthread_self(), sig);"  */
 
-  if (__pthread_kill != NULL && __pthread_threads != NULL)
+  if (__pthread_kill != NULL && GL (dl_pthread_threads) != NULL)
     {
       int err;
       err = __pthread_kill (__pthread_self (), signo);
diff --git a/sysdeps/htl/thrd_current.c b/sysdeps/htl/thrd_current.c
index eecb86a..8735967 100644
--- a/sysdeps/htl/thrd_current.c
+++ b/sysdeps/htl/thrd_current.c
@@ -17,14 +17,19 @@
    <https://www.gnu.org/licenses/>.  */
 
 #include "thrd_priv.h"
+#include <ldsodefs.h>
 
 #pragma weak __pthread_self
 #pragma weak __pthread_threads
 
+#ifndef SHARED
+#pragma weak _dl_pthread_threads
+#endif
+
 thrd_t
 thrd_current (void)
 {
-  if (__pthread_threads)
+  if (GL (dl_pthread_threads))
     return (thrd_t) __pthread_self ();
 
   return (thrd_t) 0;
diff --git a/sysdeps/mach/hurd/htl/pt-sigstate-init.c b/sysdeps/mach/hurd/htl/pt-sigstate-init.c
index 399068c..6f43ade 100644
--- a/sysdeps/mach/hurd/htl/pt-sigstate-init.c
+++ b/sysdeps/mach/hurd/htl/pt-sigstate-init.c
@@ -37,7 +37,7 @@ __pthread_sigstate_init (struct __pthread *thread)
       struct hurd_sigstate *ss = _hurd_thread_sigstate (thread->kernel_thread);
       _hurd_sigstate_set_global_rcv (ss);
     }
-  else if (__pthread_num_threads >= 2)
+  else if (GL (dl_pthread_num_threads) >= 2)
     do_init_global = 1;
 
   return 0;
diff --git a/sysdeps/mach/hurd/htl/pt-sysdep.c b/sysdeps/mach/hurd/htl/pt-sysdep.c
index 03ff807..2fd0a8d 100644
--- a/sysdeps/mach/hurd/htl/pt-sysdep.c
+++ b/sysdeps/mach/hurd/htl/pt-sysdep.c
@@ -45,7 +45,7 @@ _init_routine (void *stack)
   int err;
   pthread_attr_t attr, *attrp = 0;
 
-  if (__pthread_threads != NULL)
+  if (GL (dl_pthread_threads) != NULL)
     /* Already initialized */
     return;
 
diff --git a/sysdeps/mach/hurd/htl/pt-sysdep.h b/sysdeps/mach/hurd/htl/pt-sysdep.h
index acd4fce..d90563a 100644
--- a/sysdeps/mach/hurd/htl/pt-sysdep.h
+++ b/sysdeps/mach/hurd/htl/pt-sysdep.h
@@ -37,7 +37,7 @@ extern __thread struct __pthread *___pthread_self;
 	({                                                         \
 	  struct __pthread *thread;                                \
 	                                                           \
-	  assert (__pthread_threads);                              \
+	  assert (GL (dl_pthread_threads));                        \
 	  thread = ___pthread_self;                                \
 	                                                           \
 	  assert (thread);                                         \