1/*	$NetBSD: tls.c,v 1.5 2011/03/18 14:56:01 he Exp $	*/
2
3/*-
4 * Copyright (c) 2011 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Joerg Sonnenberger.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__RCSID("$NetBSD: tls.c,v 1.5 2011/03/18 14:56:01 he Exp $");
34
35#include "namespace.h"
36
37#define	_rtld_tls_allocate	__libc_rtld_tls_allocate
38#define	_rtld_tls_free		__libc_rtld_tls_free
39
40#include <sys/tls.h>
41
42#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
43
44#include <sys/param.h>
45#include <sys/mman.h>
46#include <link_elf.h>
47#include <lwp.h>
48#include <stddef.h>
49#include <stdlib.h>
50#include <string.h>
51#include <unistd.h>
52
53__dso_hidden void	__libc_static_tls_setup(void);
54
55static const void *tls_initaddr;
56static size_t tls_initsize;
57static size_t tls_size;
58static size_t tls_allocation;
59static void *initial_thread_tcb;
60
61void * __libc_tls_get_addr(void);
62
63__weak_alias(__tls_get_addr, __libc_tls_get_addr)
64#ifdef __i386__
65__weak_alias(___tls_get_addr, __libc_tls_get_addr)
66#endif
67
68void *
69__libc_tls_get_addr(void)
70{
71
72	abort();
73	/* NOTREACHED */
74}
75
76__weak_alias(_rtld_tls_allocate, __libc_rtld_tls_allocate)
77
78struct tls_tcb *
79_rtld_tls_allocate(void)
80{
81	struct tls_tcb *tcb;
82	uint8_t *p;
83
84	if (initial_thread_tcb == NULL) {
85#ifdef __HAVE_TLS_VARIANT_II
86		tls_size = roundup2(tls_size, sizeof(void *));
87#endif
88		tls_allocation = tls_size + sizeof(*tcb);
89
90		initial_thread_tcb = p = mmap(NULL, tls_allocation,
91		    PROT_READ | PROT_WRITE, MAP_ANON, -1, 0);
92	} else {
93		p = calloc(1, tls_allocation);
94	}
95	if (p == NULL) {
96		static const char msg[] =  "TLS allocation failed, terminating\n";
97		write(STDERR_FILENO, msg, sizeof(msg));
98		_exit(127);
99	}
100#ifdef __HAVE_TLS_VARIANT_I
101	/* LINTED */
102	tcb = (struct tls_tcb *)p;
103	p += sizeof(struct tls_tcb);
104#else
105	/* LINTED tls_size is rounded above */
106	tcb = (struct tls_tcb *)(p + tls_size);
107	tcb->tcb_self = tcb;
108#endif
109	memcpy(p, tls_initaddr, tls_initsize);
110
111	return tcb;
112}
113
114__weak_alias(_rtld_tls_free, __libc_rtld_tls_free)
115
116void
117_rtld_tls_free(struct tls_tcb *tcb)
118{
119	uint8_t *p;
120
121#ifdef __HAVE_TLS_VARIANT_I
122	/* LINTED */
123	p = (uint8_t *)tcb;
124#else
125	/* LINTED */
126	p = (uint8_t *)tcb - tls_size;
127#endif
128	if (p == initial_thread_tcb)
129		munmap(p, tls_allocation);
130	else
131		free(p);
132}
133
134__weakref_visible int rtld_DYNAMIC __weak_reference(_DYNAMIC);
135
136static int
137__libc_static_tls_setup_cb(struct dl_phdr_info *data, size_t len, void *cookie)
138{
139	const Elf_Phdr *phdr = data->dlpi_phdr;
140	const Elf_Phdr *phlimit = data->dlpi_phdr + data->dlpi_phnum;
141
142	for (; phdr < phlimit; ++phdr) {
143		if (phdr->p_type != PT_TLS)
144			continue;
145		tls_initaddr = (void *)(phdr->p_vaddr + data->dlpi_addr);
146		tls_initsize = phdr->p_filesz;
147		tls_size = phdr->p_memsz;
148	}
149	return 0;
150}
151
152void
153__libc_static_tls_setup(void)
154{
155	struct tls_tcb *tcb;
156
157	if (&rtld_DYNAMIC != NULL) {
158#ifdef __powerpc__
159		/*
160		 * Old powerpc crt0's are going to overwrite r2 so we need to
161		 * restore it but only do so if the saved value isn't NULL (if
162		 * it is NULL, ld.elf_so doesn't have the matching change).
163		 */
164		if ((tcb = _lwp_getprivate()) != NULL)
165			__lwp_settcb(tcb);
166#endif
167		return;
168	}
169
170	dl_iterate_phdr(__libc_static_tls_setup_cb, NULL);
171
172	tcb = _rtld_tls_allocate();
173#ifdef __HAVE___LWP_SETTCB
174	__lwp_settcb(tcb);
175#else
176	_lwp_setprivate(tcb);
177#endif
178}
179
180#endif /* __HAVE_TLS_VARIANT_I || __HAVE_TLS_VARIANT_II */
181