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>
40 #include "libc_private.h"
42 /* Provided by jemalloc to avoid bootstrapping issues. */
43 void *__jemalloc_a0malloc(size_t size);
44 void *__jemalloc_a0calloc(size_t num, size_t size);
45 void __jemalloc_a0free(void *ptr);
47 __weak_reference(__libc_allocate_tls, _rtld_allocate_tls);
48 __weak_reference(__libc_free_tls, _rtld_free_tls);
52 __weak_reference(___libc_tls_get_addr, ___tls_get_addr);
53 __attribute__((__regparm__(1))) void * ___libc_tls_get_addr(void *);
57 void * __libc_tls_get_addr(void *);
58 __weak_reference(__libc_tls_get_addr, __tls_get_addr);
60 void *_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign);
61 void _rtld_free_tls(void *tls, size_t tcbsize, size_t tcbalign);
62 void *__libc_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign);
63 void __libc_free_tls(void *tls, size_t tcbsize, size_t tcbalign);
65 #if defined(__ia64__) || defined(__amd64__)
66 #define TLS_TCB_ALIGN 16
67 #elif defined(__powerpc__) || defined(__i386__) || defined(__arm__) || \
68 defined(__sparc64__) || defined(__mips__)
69 #define TLS_TCB_ALIGN sizeof(void *)
71 #error TLS_TCB_ALIGN undefined for target architecture
74 #if defined(__arm__) || defined(__ia64__) || defined(__mips__) || \
78 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__)
79 #define TLS_VARIANT_II
84 #define round(size, align) \
85 (((size) + (align) - 1) & ~((align) - 1))
87 static size_t tls_static_space;
88 static size_t tls_init_size;
89 static void *tls_init;
96 __attribute__((__regparm__(1)))
98 ___libc_tls_get_addr(void *ti __unused)
106 __libc_tls_get_addr(void *ti __unused)
115 #define TLS_TCB_SIZE (2 * sizeof(void *))
118 * Free Static TLS using the Variant I method.
121 __libc_free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused)
126 tls = (Elf_Addr **)((Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE);
128 __jemalloc_a0free(dtv);
129 __jemalloc_a0free(tcb);
133 * Allocate Static TLS using the Variant I method.
136 __libc_allocate_tls(void *oldtcb, size_t tcbsize, size_t tcbalign __unused)
142 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
145 tcb = __jemalloc_a0calloc(1, tls_static_space + tcbsize - TLS_TCB_SIZE);
146 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
148 if (oldtcb != NULL) {
149 memcpy(tls, oldtcb, tls_static_space);
150 __jemalloc_a0free(oldtcb);
152 /* Adjust the DTV. */
154 dtv[2] = (Elf_Addr)tls + TLS_TCB_SIZE;
156 dtv = __jemalloc_a0malloc(3 * sizeof(Elf_Addr));
160 dtv[2] = (Elf_Addr)tls + TLS_TCB_SIZE;
162 if (tls_init_size > 0)
163 memcpy((void*)dtv[2], tls_init, tls_init_size);
164 if (tls_static_space > tls_init_size)
165 memset((void*)(dtv[2] + tls_init_size), 0,
166 tls_static_space - tls_init_size);
174 #ifdef TLS_VARIANT_II
176 #define TLS_TCB_SIZE (3 * sizeof(Elf_Addr))
179 * Free Static TLS using the Variant II method.
182 __libc_free_tls(void *tcb, size_t tcbsize __unused, size_t tcbalign)
186 Elf_Addr tlsstart, tlsend;
189 * Figure out the size of the initial TLS block so that we can
190 * find stuff which ___tls_get_addr() allocated dynamically.
192 size = round(tls_static_space, tcbalign);
194 dtv = ((Elf_Addr**)tcb)[1];
195 tlsend = (Elf_Addr) tcb;
196 tlsstart = tlsend - size;
197 __jemalloc_a0free((void*) tlsstart);
198 __jemalloc_a0free(dtv);
202 * Allocate Static TLS using the Variant II method.
205 __libc_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
210 Elf_Addr segbase, oldsegbase;
212 size = round(tls_static_space, tcbalign);
214 if (tcbsize < 2 * sizeof(Elf_Addr))
215 tcbsize = 2 * sizeof(Elf_Addr);
216 tls = __jemalloc_a0calloc(1, size + tcbsize);
217 dtv = __jemalloc_a0malloc(3 * sizeof(Elf_Addr));
219 segbase = (Elf_Addr)(tls + size);
220 ((Elf_Addr*)segbase)[0] = segbase;
221 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
225 dtv[2] = segbase - tls_static_space;
229 * Copy the static TLS block over whole.
231 oldsegbase = (Elf_Addr) oldtls;
232 memcpy((void *)(segbase - tls_static_space),
233 (const void *)(oldsegbase - tls_static_space),
237 * We assume that this block was the one we created with
238 * allocate_initial_tls().
240 _rtld_free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
242 memcpy((void *)(segbase - tls_static_space),
243 tls_init, tls_init_size);
244 memset((void *)(segbase - tls_static_space + tls_init_size),
245 0, tls_static_space - tls_init_size);
248 return (void*) segbase;
251 #endif /* TLS_VARIANT_II */
256 __libc_allocate_tls(void *oldtls __unused, size_t tcbsize __unused,
257 size_t tcbalign __unused)
263 __libc_free_tls(void *tcb __unused, size_t tcbsize __unused,
264 size_t tcbalign __unused)
270 extern char **environ;
277 Elf_Auxinfo *aux, *auxp;
283 sp = (Elf_Addr *) environ;
286 aux = (Elf_Auxinfo *) sp;
289 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
290 switch (auxp->a_type) {
292 phdr = auxp->a_un.a_ptr;
296 phent = auxp->a_un.a_val;
300 phnum = auxp->a_un.a_val;
304 if (phdr == 0 || phent != sizeof(Elf_Phdr) || phnum == 0)
307 for (i = 0; (unsigned) i < phnum; i++) {
308 if (phdr[i].p_type == PT_TLS) {
309 tls_static_space = round(phdr[i].p_memsz,
311 tls_init_size = phdr[i].p_filesz;
312 tls_init = (void*) phdr[i].p_vaddr;
318 * tls_static_space should include space for TLS structure
320 tls_static_space += TLS_TCB_SIZE;
323 tls = _rtld_allocate_tls(NULL, TLS_TCB_SIZE, TLS_TCB_ALIGN);