minix/lib/libc/tls/tls.c

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/* $NetBSD: tls.c,v 1.6 2011/04/07 02:19:28 matt Exp $ */
/*-
* Copyright (c) 2011 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Joerg Sonnenberger.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: tls.c,v 1.6 2011/04/07 02:19:28 matt Exp $");
#include "namespace.h"
#define _rtld_tls_allocate __libc_rtld_tls_allocate
#define _rtld_tls_free __libc_rtld_tls_free
#include <sys/tls.h>
#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
#include <sys/param.h>
#include <sys/mman.h>
#include <link_elf.h>
#include <lwp.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
__dso_hidden void __libc_static_tls_setup(void);
static const void *tls_initaddr;
static size_t tls_initsize;
static size_t tls_size;
static size_t tls_allocation;
static void *initial_thread_tcb;
void * __libc_tls_get_addr(void);
__weak_alias(__tls_get_addr, __libc_tls_get_addr)
#ifdef __i386__
__weak_alias(___tls_get_addr, __libc_tls_get_addr)
#endif
void *
__libc_tls_get_addr(void)
{
abort();
/* NOTREACHED */
}
__weak_alias(_rtld_tls_allocate, __libc_rtld_tls_allocate)
struct tls_tcb *
_rtld_tls_allocate(void)
{
struct tls_tcb *tcb;
uint8_t *p;
if (initial_thread_tcb == NULL) {
#ifdef __HAVE_TLS_VARIANT_II
tls_size = roundup2(tls_size, sizeof(void *));
#endif
tls_allocation = tls_size + sizeof(*tcb);
initial_thread_tcb = p = mmap(NULL, tls_allocation,
PROT_READ | PROT_WRITE, MAP_ANON, -1, 0);
} else {
p = calloc(1, tls_allocation);
}
if (p == NULL) {
static const char msg[] = "TLS allocation failed, terminating\n";
write(STDERR_FILENO, msg, sizeof(msg));
_exit(127);
}
#ifdef __HAVE_TLS_VARIANT_I
/* LINTED */
tcb = (struct tls_tcb *)p;
p += sizeof(struct tls_tcb);
#else
/* LINTED tls_size is rounded above */
tcb = (struct tls_tcb *)(p + tls_size);
tcb->tcb_self = tcb;
#endif
memcpy(p, tls_initaddr, tls_initsize);
return tcb;
}
__weak_alias(_rtld_tls_free, __libc_rtld_tls_free)
void
_rtld_tls_free(struct tls_tcb *tcb)
{
uint8_t *p;
#ifdef __HAVE_TLS_VARIANT_I
/* LINTED */
p = (uint8_t *)tcb;
#else
/* LINTED */
p = (uint8_t *)tcb - tls_size;
#endif
if (p == initial_thread_tcb)
munmap(p, tls_allocation);
else
free(p);
}
__weakref_visible int rtld_DYNAMIC __weak_reference(_DYNAMIC);
static int
__libc_static_tls_setup_cb(struct dl_phdr_info *data, size_t len, void *cookie)
{
const Elf_Phdr *phdr = data->dlpi_phdr;
const Elf_Phdr *phlimit = data->dlpi_phdr + data->dlpi_phnum;
for (; phdr < phlimit; ++phdr) {
if (phdr->p_type != PT_TLS)
continue;
tls_initaddr = (void *)(phdr->p_vaddr + data->dlpi_addr);
tls_initsize = phdr->p_filesz;
tls_size = phdr->p_memsz;
}
return 0;
}
void
__libc_static_tls_setup(void)
{
struct tls_tcb *tcb;
if (&rtld_DYNAMIC != NULL) {
#ifdef __powerpc__
/*
* Old powerpc crt0's are going to overwrite r2 so we need to
* restore it but only do so if the saved value isn't NULL (if
* it is NULL, ld.elf_so doesn't have the matching change).
*/
if ((tcb = _lwp_getprivate()) != NULL)
__lwp_settcb(tcb);
#endif
return;
}
dl_iterate_phdr(__libc_static_tls_setup_cb, NULL);
tcb = _rtld_tls_allocate();
#ifdef __HAVE___LWP_SETTCB
__lwp_settcb(tcb);
#else
_lwp_setprivate(tcb);
#endif
}
#endif /* __HAVE_TLS_VARIANT_I || __HAVE_TLS_VARIANT_II */