1a78fbb5c8
Since e19d702b8e, dlsym and friends use recursive mutexes that
require the current thread id, which is not available before the libc
constructor. This prevents us from using dlsym() in .preinit_array.
This change moves TLS initialization from libc constructor to the earliest
possible point - immediately after linker itself is relocated. As a result,
pthread_internal_t for the initial thread is available from the start.
As a bonus, values stored in TLS in .preinit_array are not lost when libc is
initialized.
Change-Id: Iee5a710ee000173bff63e924adeb4a4c600c1e2d
103 lines
3.4 KiB
C
103 lines
3.4 KiB
C
/*
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* Copyright (C) 2008 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* libc_init_static.c
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*
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* The program startup function __libc_init() defined here is
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* used for static executables only (i.e. those that don't depend
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* on shared libraries). It is called from arch-$ARCH/bionic/crtbegin_static.S
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* which is directly invoked by the kernel when the program is launched.
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*
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* The 'structors' parameter contains pointers to various initializer
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* arrays that must be run before the program's 'main' routine is launched.
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*/
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdint.h>
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#include <elf.h>
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#include "pthread_internal.h"
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#include "atexit.h"
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#include "libc_init_common.h"
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#include <bionic_tls.h>
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#include <errno.h>
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static void call_array(void(**list)())
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{
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// First element is -1, list is null-terminated
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while (*++list) {
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(*list)();
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}
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}
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__noreturn void __libc_init(uintptr_t *elfdata,
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void (*onexit)(void),
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int (*slingshot)(int, char**, char**),
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structors_array_t const * const structors)
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{
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int argc;
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char **argv, **envp;
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__libc_init_tls(NULL);
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/* get the initial thread from TLS and add it to gThreadList */
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_pthread_internal_add(__get_thread());
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/* Initialize the C runtime environment */
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__libc_init_common(elfdata);
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/* Several Linux ABIs don't pass the onexit pointer, and the ones that
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* do never use it. Therefore, we ignore it.
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*/
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/* pre-init array. */
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call_array(structors->preinit_array);
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#ifndef __i386__
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/* .ctors section initializers, for non-arm-eabi ABIs */
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call_array(structors->ctors_array);
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#endif
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// call static constructors
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call_array(structors->init_array);
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argc = (int) *elfdata;
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argv = (char**)(elfdata + 1);
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envp = argv + argc + 1;
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/* The executable may have its own destructors listed in its .fini_array
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* so we need to ensure that these are called when the program exits
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* normally.
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*/
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if (structors->fini_array)
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__cxa_atexit(__libc_fini,structors->fini_array,NULL);
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exit(slingshot(argc, argv, envp));
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}
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