Attempt to eliminate PLT relocations from rwlock aquire/release

path, making them suitable for direct use by the dynamic loader.

Register libpthread-specific locking API with rtld on startup.

This still has some rough edges with signals which should be
addresses later.

Approved by:	re (scottl)

1 files changed, 137 insertions, 0 deletions

diff --git a/lib/libpthread/thread/thr_rtld.c b/lib/libpthread/thread/thr_rtld.c
new file mode 100644
index 0000000..c1ee77e
--- /dev/null
+++ b/lib/libpthread/thread/thr_rtld.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2001 Alexander Kabaev
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer
+ *    in this position and unchanged.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+#include <sys/cdefs.h>
+#include <rtld_lock.h>
+#include "thr_private.h"
+
+static void *_thr_rtld_lock_create();
+static void  _thr_rtld_lock_destroy(void *);
+static void  _thr_rtld_rlock_acquire(void *);
+static void  _thr_rtld_wlock_acquire(void *);
+static void  _thr_rtld_lock_release(void *);
+static int   _thr_rtld_set_flag(int);
+static int   _thr_rtld_clr_flag(int);
+
+static void *
+_thr_rtld_lock_create()
+{
+	pthread_rwlock_t prwlock;
+	if (_pthread_rwlock_init(&prwlock, NULL))
+		return (NULL);
+	return (prwlock);
+}
+
+static void
+_thr_rtld_lock_destroy(void *lock)
+{
+	pthread_rwlock_t prwlock = (pthread_rwlock_t)lock;
+	if (prwlock != NULL)
+		_pthread_rwlock_destroy(&prwlock);
+}
+
+static void
+_thr_rtld_rlock_acquire(void *lock)
+{
+	pthread_rwlock_t prwlock = (pthread_rwlock_t)lock;
+	_thr_rwlock_rdlock(&prwlock);
+}
+
+static void
+_thr_rtld_wlock_acquire(void *lock)
+{
+	pthread_rwlock_t prwlock = (pthread_rwlock_t)lock;
+	_thr_rwlock_wrlock(&prwlock);
+}
+
+static void
+_thr_rtld_lock_release(void *lock)
+{
+	pthread_rwlock_t prwlock = (pthread_rwlock_t)lock;
+	_thr_rwlock_unlock(&prwlock);
+}
+
+
+static int
+_thr_rtld_set_flag(int mask)
+{
+	struct pthread *curthread;
+	int bits;
+
+	curthread = _get_curthread();
+
+	if (curthread != NULL) {
+		bits = curthread->rtld_bits;
+		curthread->rtld_bits |= mask;
+	} else {
+		bits = 0;
+		PANIC("No current thread in rtld call");
+	}
+
+	return (bits);
+}
+
+static int
+_thr_rtld_clr_flag(int mask)
+{
+	struct pthread *curthread;
+	int bits;
+
+	curthread = _get_curthread();
+
+	if (curthread != NULL) {
+		bits = curthread->rtld_bits;
+		curthread->rtld_bits &= ~mask;
+	} else {
+		bits = 0;
+		PANIC("No current thread in rtld call");
+	}
+	return (bits);
+}
+
+void
+_thr_rtld_init()
+{
+	struct RtldLockInfo li;
+        li.lock_create  = _thr_rtld_lock_create;
+        li.lock_destroy = _thr_rtld_lock_destroy;
+        li.rlock_acquire = _thr_rtld_rlock_acquire;
+        li.wlock_acquire = _thr_rtld_wlock_acquire;
+        li.lock_release  = _thr_rtld_lock_release;
+        li.thread_set_flag = _thr_rtld_set_flag;
+        li.thread_clr_flag = _thr_rtld_clr_flag;
+        li.at_fork = NULL;
+	_rtld_thread_init(&li);
+}
+
+void
+_thr_rtld_fini()
+{
+	_rtld_thread_init(NULL);
+}