2 * Copyright (c) 2004 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * Define stubs for TLS internals so that programs and libraries can
31 * link. These functions will be replaced by functional versions at
32 * runtime from ld-elf.so.1.
35 #include <sys/cdefs.h>
41 #include "libc_private.h"
43 /* XXX not sure what variants to use for arm. */
45 __weak_reference(__libc_allocate_tls, _rtld_allocate_tls);
46 __weak_reference(__libc_free_tls, _rtld_free_tls);
50 __weak_reference(___libc_tls_get_addr, ___tls_get_addr);
51 __attribute__((__regparm__(1))) void * ___libc_tls_get_addr(void *);
55 void * __libc_tls_get_addr(void *);
56 __weak_reference(__libc_tls_get_addr, __tls_get_addr);
58 void *_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign);
59 void _rtld_free_tls(void *tls, size_t tcbsize, size_t tcbalign);
60 void *__libc_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign);
61 void __libc_free_tls(void *tls, size_t tcbsize, size_t tcbalign);
63 #if defined(__ia64__) || defined(__alpha__) || defined(__powerpc__)
66 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \
68 #define TLS_VARIANT_II
73 #define round(size, align) \
74 (((size) + (align) - 1) & ~((align) - 1))
76 static size_t tls_static_space;
77 static size_t tls_init_size;
79 static size_t tls_init_offset;
81 static void *tls_init;
88 __attribute__((__regparm__(1)))
90 ___libc_tls_get_addr(void *ti __unused)
98 __libc_tls_get_addr(void *ti __unused)
108 * Free Static TLS using the Variant I method.
111 __libc_free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign __unused)
115 dtv = ((Elf_Addr**)tls)[0];
121 * Allocate Static TLS using the Variant I method.
124 __libc_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign __unused)
130 size = tls_static_space;
135 dtv = malloc(3 * sizeof(Elf_Addr));
137 *(Elf_Addr **) tls = dtv;
141 dtv[2] = (Elf_Addr)(tls + tls_init_offset);
144 * Copy the static TLS block over whole.
146 memcpy(tls + tls_init_offset,
147 (char *)oldtls + tls_init_offset,
148 tls_static_space - tls_init_offset);
151 * We assume that this block was the one we created with
152 * allocate_initial_tls().
154 _rtld_free_tls(oldtls, 2 * sizeof(Elf_Addr), sizeof(Elf_Addr));
156 memcpy(tls + tls_init_offset, tls_init, tls_init_size);
157 memset(tls + tls_init_offset + tls_init_size,
158 0, tls_static_space - tls_init_size);
166 #ifdef TLS_VARIANT_II
169 * Free Static TLS using the Variant II method.
172 __libc_free_tls(void *tcb, size_t tcbsize __unused, size_t tcbalign)
176 Elf_Addr tlsstart, tlsend;
179 * Figure out the size of the initial TLS block so that we can
180 * find stuff which ___tls_get_addr() allocated dynamically.
182 size = round(tls_static_space, tcbalign);
184 dtv = ((Elf_Addr**)tcb)[1];
185 tlsend = (Elf_Addr) tcb;
186 tlsstart = tlsend - size;
187 free((void*) tlsstart);
192 * Allocate Static TLS using the Variant II method.
195 __libc_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
200 Elf_Addr segbase, oldsegbase;
202 size = round(tls_static_space, tcbalign);
204 assert(tcbsize >= 2*sizeof(Elf_Addr));
205 tls = malloc(size + tcbsize);
206 dtv = malloc(3 * sizeof(Elf_Addr));
208 segbase = (Elf_Addr)(tls + size);
209 ((Elf_Addr*)segbase)[0] = segbase;
210 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
214 dtv[2] = segbase - tls_static_space;
218 * Copy the static TLS block over whole.
220 oldsegbase = (Elf_Addr) oldtls;
221 memcpy((void *)(segbase - tls_static_space),
222 (const void *)(oldsegbase - tls_static_space),
226 * We assume that this block was the one we created with
227 * allocate_initial_tls().
229 _rtld_free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
231 memcpy((void *)(segbase - tls_static_space),
232 tls_init, tls_init_size);
233 memset((void *)(segbase - tls_static_space + tls_init_size),
234 0, tls_static_space - tls_init_size);
237 return (void*) segbase;
240 #endif /* TLS_VARIANT_II */
245 __libc_allocate_tls(void *oldtls __unused, size_t tcbsize __unused,
246 size_t tcbalign __unused)
252 __libc_free_tls(void *tcb __unused, size_t tcbsize __unused,
253 size_t tcbalign __unused)
259 extern char **environ;
266 Elf_Auxinfo *aux, *auxp;
272 sp = (Elf_Addr *) environ;
275 aux = (Elf_Auxinfo *) sp;
278 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
279 switch (auxp->a_type) {
281 phdr = auxp->a_un.a_ptr;
285 phent = auxp->a_un.a_val;
289 phnum = auxp->a_un.a_val;
293 if (phdr == 0 || phent != sizeof(Elf_Phdr) || phnum == 0)
296 for (i = 0; (unsigned) i < phnum; i++) {
297 if (phdr[i].p_type == PT_TLS) {
299 tls_static_space = round(2*sizeof(Elf_Addr),
300 phdr[i].p_align) + phdr[i].p_memsz;
301 tls_init_offset = round(2*sizeof(Elf_Addr),
304 tls_static_space = round(phdr[i].p_memsz,
307 tls_init_size = phdr[i].p_filesz;
308 tls_init = (void*) phdr[i].p_vaddr;
312 tls = _rtld_allocate_tls(NULL, 2*sizeof(Elf_Addr),