1/* $NetBSD: h_atexit.c,v 1.1 2011/01/12 19:44:08 pgoyette Exp $ */ 2 3/*- 4 * Copyright (c) 2011 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code was contributed to The NetBSD Foundation by Jason R. Thorpe. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <sys/cdefs.h> 32__COPYRIGHT("@(#) Copyright (c) 2011\ 33 The NetBSD Foundation, inc. All rights reserved."); 34__RCSID("$NetBSD: h_atexit.c,v 1.1 2011/01/12 19:44:08 pgoyette Exp $"); 35 36#include <stdio.h> 37#include <stdlib.h> 38#include <signal.h> 39#include <string.h> 40#include <unistd.h> 41 42extern int __cxa_atexit(void (*func)(void *), void *, void *); 43extern void __cxa_finalize(void *); 44 45#ifdef __FreeBSD__ 46/* 47 * On shared object unload, in __cxa_finalize, call and clear all installed 48 * atexit and __cxa_atexit handlers that are either installed by unloaded 49 * dso, or points to the functions provided by the dso. 50 * 51 * The reason of the change is to ensure that there is no lingering pointers 52 * to the unloaded code after the dlclose(3). It is known reason for infinite 53 * stream of the crash reports for many programs which use loadable modules 54 * and fail to properly clean on module unload. Examples are apache, php, 55 * perl etc. 56 * 57 * You pass the &dso_handle_1 and &dso_handle_2, which points inside the 58 * main binary, to the registration function. The code from r211706, 59 * correctly detects that they are for the main binary, and on the first 60 * call to __cxa_finalize(), which also pass pointer to main binary, all 61 * registered functions from the main binary are executed. 62 */ 63 64static void *dso_handle_1 = (void *)1; 65static void *dso_handle_2 = (void *)2; 66static void *dso_handle_3 = (void *)3; 67#else 68static int dso_handle_1; 69static int dso_handle_2; 70static int dso_handle_3; 71#endif 72 73static int arg_1; 74static int arg_2; 75static int arg_3; 76 77static int exiting_state; 78 79#define ASSERT(expr) \ 80do { \ 81 if ((expr) == 0) { \ 82 write(STDERR_FILENO, __func__, strlen(__func__)); \ 83 write(STDERR_FILENO, ": ", 2); \ 84 write(STDERR_FILENO, __STRING(expr), \ 85 strlen(__STRING(expr))); \ 86 write(STDERR_FILENO, "\n", 1); \ 87 my_abort(); \ 88 } \ 89} while (/*CONSTCOND*/0) 90 91#define SUCCESS() \ 92do { \ 93 write(STDOUT_FILENO, __func__, strlen(__func__)); \ 94 write(STDOUT_FILENO, "\n", 1); \ 95} while (/*CONSTCOND*/0) 96 97static void 98my_abort(void) 99{ 100 101 kill(getpid(), SIGABRT); 102 /* NOTREACHED */ 103} 104 105static void 106cxa_handler_5(void *arg) 107{ 108 static int cxa_handler_5_called; 109 110 ASSERT(arg == (void *)&arg_1); 111 ASSERT(cxa_handler_5_called == 0); 112 ASSERT(exiting_state == 5); 113 114 exiting_state--; 115 cxa_handler_5_called = 1; 116 SUCCESS(); 117} 118 119static void 120cxa_handler_4(void *arg) 121{ 122 static int cxa_handler_4_called; 123 124 ASSERT(arg == (void *)&arg_1); 125 ASSERT(cxa_handler_4_called == 0); 126 ASSERT(exiting_state == 4); 127 128 exiting_state--; 129 cxa_handler_4_called = 1; 130 SUCCESS(); 131} 132 133static void 134cxa_handler_3(void *arg) 135{ 136 static int cxa_handler_3_called; 137 138 ASSERT(arg == (void *)&arg_2); 139 ASSERT(cxa_handler_3_called == 0); 140 ASSERT(exiting_state == 3); 141 142 exiting_state--; 143 cxa_handler_3_called = 1; 144 SUCCESS(); 145} 146 147static void 148cxa_handler_2(void *arg) 149{ 150 static int cxa_handler_2_called; 151 152 ASSERT(arg == (void *)&arg_3); 153 ASSERT(cxa_handler_2_called == 0); 154 ASSERT(exiting_state == 2); 155 156 exiting_state--; 157 cxa_handler_2_called = 1; 158 SUCCESS(); 159} 160 161static void 162normal_handler_1(void) 163{ 164 static int normal_handler_1_called; 165 166 ASSERT(normal_handler_1_called == 0); 167 ASSERT(exiting_state == 1); 168 169 exiting_state--; 170 normal_handler_1_called = 1; 171 SUCCESS(); 172} 173 174static void 175normal_handler_0(void) 176{ 177 static int normal_handler_0_called; 178 179 ASSERT(normal_handler_0_called == 0); 180 ASSERT(exiting_state == 0); 181 182 normal_handler_0_called = 1; 183 SUCCESS(); 184} 185 186int 187main(int argc, char *argv[]) 188{ 189 190 exiting_state = 5; 191 192 ASSERT(0 == atexit(normal_handler_0)); 193 ASSERT(0 == atexit(normal_handler_1)); 194#ifdef __FreeBSD__ 195 ASSERT(0 == __cxa_atexit(cxa_handler_4, &arg_1, dso_handle_1)); 196 ASSERT(0 == __cxa_atexit(cxa_handler_5, &arg_1, dso_handle_1)); 197 ASSERT(0 == __cxa_atexit(cxa_handler_3, &arg_2, dso_handle_2)); 198 ASSERT(0 == __cxa_atexit(cxa_handler_2, &arg_3, dso_handle_3)); 199 200 __cxa_finalize(dso_handle_1); 201 __cxa_finalize(dso_handle_2); 202#else 203 ASSERT(0 == __cxa_atexit(cxa_handler_4, &arg_1, &dso_handle_1)); 204 ASSERT(0 == __cxa_atexit(cxa_handler_5, &arg_1, &dso_handle_1)); 205 ASSERT(0 == __cxa_atexit(cxa_handler_3, &arg_2, &dso_handle_2)); 206 ASSERT(0 == __cxa_atexit(cxa_handler_2, &arg_3, &dso_handle_3)); 207 208 __cxa_finalize(&dso_handle_1); 209 __cxa_finalize(&dso_handle_2); 210#endif 211 exit(0); 212} 213