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70 lines
1.8 KiB
70 lines
1.8 KiB
/*
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* Copyright (C) 2014 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <dlfcn.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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static uintptr_t g_flag = 0;
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static void __attribute__((constructor)) init_flag() {
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g_flag = reinterpret_cast<uintptr_t>(dlsym(RTLD_DEFAULT, "dlsym"));
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}
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static const char* is_ctor_called() __attribute__ ((ifunc("is_ctor_called_ifun")));
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extern "C" const char* foo() __attribute__ ((ifunc ("foo_ifunc")));
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// Static linker creates GLOBAL/IFUNC symbol and JUMP_SLOT relocation type for plt segment
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extern "C" const char* is_ctor_called_jump_slot() __attribute__ ((ifunc("is_ctor_called_ifun")));
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extern "C" const char* is_ctor_called_irelative() {
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// Call internal ifunc-resolved function with IRELATIVE reloc
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return is_ctor_called();
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}
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extern "C" const char* return_true() {
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return "true";
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}
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extern "C" const char* return_false() {
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return "false";
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}
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extern "C" const char* f1() {
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return "unset";
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}
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extern "C" const char* f2() {
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return "set";
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}
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typedef const char* (*fn_ptr)();
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extern "C" fn_ptr is_ctor_called_ifun() {
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return g_flag == 0 ? return_false : return_true;
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}
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extern "C" fn_ptr foo_ifunc() {
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char* choice = getenv("IFUNC_CHOICE");
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return choice == nullptr ? f1 : f2;
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}
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extern "C" const char* foo_library() {
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return foo();
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}
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