1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <stdio.h> 18 #include <stdlib.h> 19 20 static int g_flag = 0; 21 22 static void __attribute__((constructor)) init_flag() { 23 g_flag = 1; 24 } 25 26 static const char* is_ctor_called() __attribute__ ((ifunc("is_ctor_called_ifun"))); 27 28 const char* foo() __attribute__ ((ifunc ("foo_ifunc"))); 29 30 // Static linker creates GLOBAL/IFUNC symbol and JUMP_SLOT relocation type for plt segment 31 const char* is_ctor_called_jump_slot() __attribute__ ((ifunc("is_ctor_called_ifun"))); 32 33 const char* is_ctor_called_irelative() { 34 // Call internal ifunc-resolved function with IRELATIVE reloc 35 return is_ctor_called(); 36 } 37 38 const char* return_true() { 39 return "true"; 40 } 41 42 const char* return_false() { 43 return "false"; 44 } 45 46 const char* f1() { 47 return "unset"; 48 } 49 50 const char* f2() { 51 return "set"; 52 } 53 54 void* is_ctor_called_ifun() { 55 return g_flag == 0 ? return_false : return_true; 56 } 57 58 void* foo_ifunc() { 59 char* choice = getenv("IFUNC_CHOICE"); 60 return choice == NULL ? f1 : f2; 61 } 62 63 const char* foo_library() { 64 return foo(); 65 } 66
