1/* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29#include <unistd.h> 30#include <sys/syscall.h> 31 32#include "pthread_internal.h" 33 34#define FORK_FLAGS (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | SIGCHLD) 35 36int fork() { 37 __bionic_atfork_run_prepare(); 38 39 pthread_internal_t* self = __get_thread(); 40 41 // Remember the parent pid and invalidate the cached value while we fork. 42 pid_t parent_pid = self->invalidate_cached_pid(); 43 44#if defined(__x86_64__) // sys_clone's last two arguments are flipped on x86-64. 45 int result = syscall(__NR_clone, FORK_FLAGS, NULL, NULL, &(self->tid), NULL); 46#else 47 int result = syscall(__NR_clone, FORK_FLAGS, NULL, NULL, NULL, &(self->tid)); 48#endif 49 if (result == 0) { 50 self->set_cached_pid(gettid()); 51 __bionic_atfork_run_child(); 52 } else { 53 self->set_cached_pid(parent_pid); 54 __bionic_atfork_run_parent(); 55 } 56 return result; 57} 58