eb847bc866
The x86_64 build was failing because clone.S had a call to __thread_entry which was being added to a different intermediate .a on the way to making libc.so, and the linker couldn't guarantee statically that such a relocation would be possible. ld: error: out/target/product/generic_x86_64/obj/STATIC_LIBRARIES/libc_common_intermediates/libc_common.a(clone.o): requires dynamic R_X86_64_PC32 reloc against '__thread_entry' which may overflow at runtime; recompile with -fPIC This patch addresses that by ensuring that the caller and callee end up in the same intermediate .a. While I'm here, I've tried to clean up some of the mess that led to this situation too. In particular, this removes libc/private/ from the default include path (except for the DNS code), and splits out the DNS code into its own library (since it's a weird special case of upstream NetBSD code that's diverged so heavily it's unlikely ever to get back in sync). There's more cleanup of the DNS situation possible, but this is definitely a step in the right direction, and it's more than enough to get x86_64 building cleanly. Change-Id: I00425a7245b7a2573df16cc38798187d0729e7c4
111 lines
3.9 KiB
C++
111 lines
3.9 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 <elf.h>
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#include <errno.h>
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#include <stddef.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/auxv.h>
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#include <sys/mman.h>
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#include "atexit.h"
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#include "libc_init_common.h"
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#include "pthread_internal.h"
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#include "private/bionic_tls.h"
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#include "private/KernelArgumentBlock.h"
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// Returns the address of the page containing address 'x'.
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#define PAGE_START(x) ((x) & PAGE_MASK)
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// Returns the address of the next page after address 'x', unless 'x' is
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// itself at the start of a page.
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#define PAGE_END(x) PAGE_START((x) + (PAGE_SIZE-1))
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static void call_array(void(**list)()) {
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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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static void apply_gnu_relro() {
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Elf_Phdr* phdr_start = reinterpret_cast<Elf_Phdr*>(getauxval(AT_PHDR));
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unsigned long int phdr_ct = getauxval(AT_PHNUM);
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for (Elf_Phdr* phdr = phdr_start; phdr < (phdr_start + phdr_ct); phdr++) {
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if (phdr->p_type != PT_GNU_RELRO) {
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continue;
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}
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Elf_Addr seg_page_start = PAGE_START(phdr->p_vaddr);
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Elf_Addr seg_page_end = PAGE_END(phdr->p_vaddr + phdr->p_memsz);
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// Check return value here? What do we do if we fail?
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mprotect(reinterpret_cast<void*>(seg_page_start), seg_page_end - seg_page_start, PROT_READ);
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}
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}
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__noreturn void __libc_init(void* raw_args,
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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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KernelArgumentBlock args(raw_args);
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__libc_init_tls(args);
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__libc_init_common(args);
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apply_gnu_relro();
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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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call_array(structors->preinit_array);
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call_array(structors->init_array);
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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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if (structors->fini_array != NULL) {
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__cxa_atexit(__libc_fini,structors->fini_array,NULL);
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}
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exit(slingshot(args.argc, args.argv, args.envp));
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}
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