Add support for Thread Local Storage.

1 files changed, 69 insertions, 0 deletions

diff --git a/libexec/rtld-elf/rtld_tls.h b/libexec/rtld-elf/rtld_tls.h
new file mode 100644
index 0000000..b85db59
--- /dev/null
+++ b/libexec/rtld-elf/rtld_tls.h
@@ -0,0 +1,69 @@
+/*-
+ * Copyright (c) 2004 Doug Rabson
+ * 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.
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ *
+ *	$FreeBSD$
+ */
+
+/*
+ * Semi-public interface from thread libraries to rtld for managing
+ * TLS.
+ */
+
+#ifndef _RTLD_TLS_H_
+#define	_RTLD_TLS_H_
+
+/*
+ * Allocate a TLS block for a new thread. The memory allocated will
+ * include 'tcbsize' bytes aligned to a 'tcbalign' boundary (in bytes)
+ * for the thread library's private purposes. The location of the TCB
+ * block is returned by this function. For architectures using
+ * 'Variant I' TLS, the thread local storage follows the TCB, and for
+ * 'Variant II', the thread local storage precedes it. For
+ * architectures using the 'Variant II' model (e.g. i386, amd64,
+ * sparc64), the TCB must begin with two pointer fields which are used
+ * by rtld for its TLS implementation. For the 'Variant I' model, the
+ * TCB must begin with a single pointer field for rtld's
+ * implementation.
+ *
+ * If the value of 'oldtls' is non-NULL, the new TLS block will be
+ * initialised using the values contained in 'oldtls' and 'oldtls'
+ * will be freed. This is typically used when initialising a thread
+ * library to migrate from using the initial bootstrap TLS block
+ * created by rtld to one which contains suitable thread library
+ * private data.
+ *
+ * The value returned from this function is suitable for installing
+ * directly into the thread pointer register.
+ */
+extern void *_rtld_allocate_tls(void* oldtls, size_t tcbsize, size_t tcbalign);
+
+/*
+ * Free a TLS block allocated using _rtld_allocate_tls(). The tcbsize
+ * and tcbalign parameters must be the same as those used to allocate
+ * the block.
+ */
+extern void _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign);
+
+#endif