/* * Copyright (C) 2012 The Android Open Source Project * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 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 COPYRIGHT HOLDERS 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 * COPYRIGHT OWNER 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 "../../bionic/libc_init_common.h" #include #include #define SECTION(name) __attribute__((__section__(name))) SECTION(".preinit_array") init_func_t* __PREINIT_ARRAY__ = (init_func_t*)-1; SECTION(".init_array.0") init_func_t* __INIT_ARRAY__ = (init_func_t*)-1; SECTION(".fini_array.0") fini_func_t* __FINI_ARRAY__ = (fini_func_t*)-1; #undef SECTION __used static void _start_main(void* raw_args) { structors_array_t array; array.preinit_array = &__PREINIT_ARRAY__; array.init_array = &__INIT_ARRAY__; array.fini_array = &__FINI_ARRAY__; __libc_init(raw_args, NULL, &main, &array); } #define PRE ".text; .global _start; .type _start,%function; _start:" #define POST "; .size _start, .-_start" #if defined(__aarch64__) __asm__(PRE "bti j; mov x29,#0; mov x30,#0; mov x0,sp; b _start_main" POST); #elif defined(__arm__) __asm__(PRE "mov fp,#0; mov lr,#0; mov r0,sp; b _start_main" POST); #elif defined(__i386__) __asm__(PRE "xorl %ebp,%ebp; movl %esp,%eax; andl $~0xf,%esp; subl $12,%esp; pushl %eax;" "call _start_main" POST); #elif defined(__riscv) __asm__(PRE "li fp,0; li ra,0; mv a0,sp; tail _start_main" POST); #elif defined(__x86_64__) __asm__(PRE "xorl %ebp, %ebp; movq %rsp,%rdi; andq $~0xf,%rsp; callq _start_main" POST); #else #error unsupported architecture #endif #undef PRE #undef POST // On arm32 and arm64, when targeting Q and up, overalign the TLS segment to // (8 * sizeof(void*)), which reserves enough space between the thread pointer // and the executable's TLS segment for Bionic's TLS slots. It has the side // effect of placing a 0-sized TLS segment into Android executables that don't // use TLS, but this should be harmless. // // To ensure that the .tdata input section isn't deleted (e.g. by // --gc-sections), the .text input section (which contains _start) has a // relocation to the .tdata input section. #if __ANDROID_API__ >= 29 #if defined(__arm__) asm(" .section .tdata,\"awT\",%progbits\n" " .p2align 5\n" " .text\n" " .reloc 0, R_ARM_NONE, .tdata\n"); #elif defined(__aarch64__) asm(" .section .tdata,\"awT\",@progbits\n" " .p2align 6\n" " .text\n" " .reloc 0, R_AARCH64_NONE, .tdata\n"); #endif #endif #include "__dso_handle.h" #include "atexit.h" #include "pthread_atfork.h"