1 /* $NetBSD: tls.c,v 1.8 2014/12/14 23:49:17 chs 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 1.8 2014/12/14 23:49:17 chs 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
55 static const void *tls_initaddr;
56 static size_t tls_initsize;
57 static size_t tls_size;
58 static size_t tls_allocation;
59 static void *initial_thread_tcb;
60
61 void * __libc_tls_get_addr(void);
62
__weak_alias(__tls_get_addr,__libc_tls_get_addr)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
68 void *
69 __libc_tls_get_addr(void)
70 {
71
72 abort();
73 /* NOTREACHED */
74 }
75
__weak_alias(_rtld_tls_allocate,__libc_rtld_tls_allocate)76 __weak_alias(_rtld_tls_allocate, __libc_rtld_tls_allocate)
77
78 struct 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
__weak_alias(_rtld_tls_free,__libc_rtld_tls_free)114 __weak_alias(_rtld_tls_free, __libc_rtld_tls_free)
115
116 void
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
136 static int __section(".text.startup")
__libc_static_tls_setup_cb(struct dl_phdr_info * data,size_t len,void * cookie)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
152 void
__libc_static_tls_setup(void)153 __libc_static_tls_setup(void)
154 {
155 struct tls_tcb *tcb;
156
157 if (&rtld_DYNAMIC != NULL) {
158 return;
159 }
160
161 dl_iterate_phdr(__libc_static_tls_setup_cb, NULL);
162
163 tcb = _rtld_tls_allocate();
164 #ifdef __HAVE___LWP_SETTCB
165 __lwp_settcb(tcb);
166 #else
167 _lwp_setprivate(tcb);
168 #endif
169 }
170
171 #endif /* __HAVE_TLS_VARIANT_I || __HAVE_TLS_VARIANT_II */
172