153c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov/* $OpenBSD: atexit.c,v 1.20 2014/07/11 09:51:37 kettenis Exp $ */ 21dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 31dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Copyright (c) 2002 Daniel Hartmeier 41dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * All rights reserved. 51dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 61dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Redistribution and use in source and binary forms, with or without 71dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * modification, are permitted provided that the following conditions 81dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * are met: 91dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * - Redistributions of source code must retain the above copyright 111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer. 121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * - Redistributions in binary form must reproduce the above 131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * copyright notice, this list of conditions and the following 141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * disclaimer in the documentation and/or other materials provided 151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * with the distribution. 161dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 171dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * POSSIBILITY OF SUCH DAMAGE. 291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <sys/types.h> 331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <sys/mman.h> 341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <stdlib.h> 351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <string.h> 361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <unistd.h> 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "atexit.h" 38ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov#include "private/thread_private.h" 391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 40f0a73476a1e08e9deab7c4df557582cda60b36d2Daniel Micay/* BEGIN android-changed */ 41f0a73476a1e08e9deab7c4df557582cda60b36d2Daniel Micay#include "private/bionic_prctl.h" 42f0a73476a1e08e9deab7c4df557582cda60b36d2Daniel Micay/* END android-changed */ 43f0a73476a1e08e9deab7c4df557582cda60b36d2Daniel Micay 449cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanovstruct atexit { 459cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov struct atexit *next; /* next in list */ 469cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov int ind; /* next index in this table */ 479cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov int max; /* max entries >= ATEXIT_SIZE */ 489cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov struct atexit_fn { 499cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov void (*fn_ptr)(void *); 509cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov void *fn_arg; /* argument for CXA callback */ 519cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov void *fn_dso; /* shared module handle */ 529cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov } fns[1]; /* the table itself */ 539cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov}; 549cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanov 559cf6fc304bbbfb26911e0b624b80d862c40b0308Dmitriy Ivanovstatic struct atexit *__atexit; 5653c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanovstatic int restartloop; 576b56691a678420477595a531b2d2829980eb51c0Dmitriy Ivanov 58ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov/* BEGIN android-changed: __unregister_atfork is used by __cxa_finalize */ 59ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanovextern void __unregister_atfork(void* dso); 60ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov/* END android-changed */ 61ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov 626b56691a678420477595a531b2d2829980eb51c0Dmitriy Ivanov/* 631dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Function pointers are stored in a linked list of pages. The list 641dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * is initially empty, and pages are allocated on demand. The first 651dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * function pointer in the first allocated page (the last one in 6653c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov * the linked list) is reserved for the cleanup function. 671dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 681dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Outside the following functions, all pages are mprotect()'ed 691dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * to prevent unintentional/malicious corruption. 701dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 711dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 721dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 731dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Register a function to be performed at exit or when a shared object 741dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * with the given dso handle is unloaded dynamically. Also used as 751dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * the backend for atexit(). For more info on this API, see: 761dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 771dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * http://www.codesourcery.com/cxx-abi/abi.html#dso-dtor 781dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 791dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectint 801dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project__cxa_atexit(void (*func)(void *), void *arg, void *dso) 811dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 821dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project struct atexit *p = __atexit; 831dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project struct atexit_fn *fnp; 84ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov size_t pgsize = getpagesize(); 851dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project int ret = -1; 861dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 87623b0d05bd924e7fa3c155492695123c87c3a2b1Dmitriy Ivanov if (pgsize < sizeof(*p)) 881dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (-1); 891dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project _ATEXIT_LOCK(); 901dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p = __atexit; 911dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (p != NULL) { 921dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (p->ind + 1 >= p->max) 931dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p = NULL; 941dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project else if (mprotect(p, pgsize, PROT_READ | PROT_WRITE)) 951dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project goto unlock; 961dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 971dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (p == NULL) { 981dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p = mmap(NULL, pgsize, PROT_READ | PROT_WRITE, 991dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project MAP_ANON | MAP_PRIVATE, -1, 0); 1001dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (p == MAP_FAILED) 1011dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project goto unlock; 102f0a73476a1e08e9deab7c4df557582cda60b36d2Daniel Micay/* BEGIN android-changed */ 103f0a73476a1e08e9deab7c4df557582cda60b36d2Daniel Micay prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, p, pgsize, 104f0a73476a1e08e9deab7c4df557582cda60b36d2Daniel Micay "atexit handlers"); 105f0a73476a1e08e9deab7c4df557582cda60b36d2Daniel Micay/* END android-changed */ 1061dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (__atexit == NULL) { 1071dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project memset(&p->fns[0], 0, sizeof(p->fns[0])); 1081dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p->ind = 1; 1091dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } else 1101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p->ind = 0; 1111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p->max = (pgsize - ((char *)&p->fns[0] - (char *)p)) / 1121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project sizeof(p->fns[0]); 1131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p->next = __atexit; 1141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project __atexit = p; 1151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1161dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fnp = &p->fns[p->ind++]; 11753c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov fnp->fn_ptr = func; 1181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fnp->fn_arg = arg; 1191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fnp->fn_dso = dso; 1201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (mprotect(p, pgsize, PROT_READ)) 1211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project goto unlock; 12253c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov restartloop = 1; 1231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project ret = 0; 1241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectunlock: 1251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project _ATEXIT_UNLOCK(); 1261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (ret); 1271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 1281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 1291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 1301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Call all handlers registered with __cxa_atexit() for the shared 1311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * object owning 'dso'. 1321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Note: if 'dso' is NULL, then all remaining handlers are called. 1331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 1341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectvoid 1351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project__cxa_finalize(void *dso) 1361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 13753c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov struct atexit *p, *q; 1381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project struct atexit_fn fn; 13953c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov int n, pgsize = getpagesize(); 1401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project static int call_depth; 1411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 1422270dfa0c418ab06e89412ea7b4ffe650490bcc9Srinavasa Nagaraju _ATEXIT_LOCK(); 1431dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project call_depth++; 1441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 14553c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanovrestart: 14653c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov restartloop = 0; 14753c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov for (p = __atexit; p != NULL; p = p->next) { 14853c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov for (n = p->ind; --n >= 0;) { 14953c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov if (p->fns[n].fn_ptr == NULL) 15053c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov continue; /* already called */ 15153c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov if (dso != NULL && dso != p->fns[n].fn_dso) 15253c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov continue; /* wrong DSO */ 15353c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov 1541dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 1551dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Mark handler as having been already called to avoid 1561dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * dupes and loops, then call the appropriate function. 1571dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 1581dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fn = p->fns[n]; 1591dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (mprotect(p, pgsize, PROT_READ | PROT_WRITE) == 0) { 16053c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov p->fns[n].fn_ptr = NULL; 1611dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project mprotect(p, pgsize, PROT_READ); 1621dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1632270dfa0c418ab06e89412ea7b4ffe650490bcc9Srinavasa Nagaraju _ATEXIT_UNLOCK(); 16453c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov (*fn.fn_ptr)(fn.fn_arg); 1652270dfa0c418ab06e89412ea7b4ffe650490bcc9Srinavasa Nagaraju _ATEXIT_LOCK(); 16653c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov if (restartloop) 16753c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov goto restart; 1681dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1691dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1701dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 17153c3c271dc9927dd280981fc23409af60f460007Dmitriy Ivanov call_depth--; 1726b56691a678420477595a531b2d2829980eb51c0Dmitriy Ivanov 1731dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 1741dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * If called via exit(), unmap the pages since we have now run 1751dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * all the handlers. We defer this until calldepth == 0 so that 1761dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * we don't unmap things prematurely if called recursively. 1771dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 1786b56691a678420477595a531b2d2829980eb51c0Dmitriy Ivanov if (dso == NULL && call_depth == 0) { 1791dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project for (p = __atexit; p != NULL; ) { 1801dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project q = p; 1811dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p = p->next; 1821dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project munmap(q, pgsize); 1831dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1841dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project __atexit = NULL; 1851dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1862270dfa0c418ab06e89412ea7b4ffe650490bcc9Srinavasa Nagaraju _ATEXIT_UNLOCK(); 187ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov 188bb46afd6c44a847efe96e30d72708fd2d0906e8cElliott Hughes extern void __libc_stdio_cleanup(void); 189bb46afd6c44a847efe96e30d72708fd2d0906e8cElliott Hughes __libc_stdio_cleanup(); 190bb46afd6c44a847efe96e30d72708fd2d0906e8cElliott Hughes 191ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov /* BEGIN android-changed: call __unregister_atfork if dso is not null */ 192ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov if (dso != NULL) { 193ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov __unregister_atfork(dso); 194ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov } 195ea295f68f1fae7c701baaa717f67296659d567acDmitriy Ivanov /* END android-changed */ 1961dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 197