| File: | src/lib/librthread/rthread_fork.c |
| Warning: | line 62, column 3 Return is prohibited after a successful vfork; call _exit() instead |
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| 1 | /* $OpenBSD: rthread_fork.c,v 1.23 2017/10/29 08:45:53 mpi Exp $ */ | |||
| 2 | ||||
| 3 | /* | |||
| 4 | * Copyright (c) 2008 Kurt Miller <kurt@openbsd.org> | |||
| 5 | * Copyright (c) 2008 Philip Guenther <guenther@openbsd.org> | |||
| 6 | * Copyright (c) 2003 Daniel Eischen <deischen@freebsd.org> | |||
| 7 | * All rights reserved. | |||
| 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. Neither the name of the author nor the names of any co-contributors | |||
| 15 | * may be used to endorse or promote products derived from this software | |||
| 16 | * without specific prior written permission. | |||
| 17 | * | |||
| 18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |||
| 19 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |||
| 20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |||
| 21 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |||
| 22 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |||
| 23 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |||
| 24 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |||
| 25 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |||
| 26 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |||
| 27 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |||
| 28 | * SUCH DAMAGE. | |||
| 29 | * | |||
| 30 | * $FreeBSD: /repoman/r/ncvs/src/lib/libc_r/uthread/uthread_atfork.c,v 1.1 2004/12/10 03:36:45 grog Exp $ | |||
| 31 | */ | |||
| 32 | ||||
| 33 | #ifndef NO_PIC | |||
| 34 | #include <sys/types.h> | |||
| 35 | #include <elf.h> | |||
| 36 | #pragma weak _DYNAMIC | |||
| 37 | #endif | |||
| 38 | ||||
| 39 | #include <errno(*__errno()).h> | |||
| 40 | #include <pthread.h> | |||
| 41 | #include <stdio.h> | |||
| 42 | #include <stdlib.h> | |||
| 43 | #include <tib.h> | |||
| 44 | #include <unistd.h> | |||
| 45 | ||||
| 46 | #include "rthread.h" | |||
| 47 | #include "rthread_cb.h" | |||
| 48 | ||||
| 49 | /* make {fork,vfork,getthrid} call _thread_sys_{fork,vfork,getthrid} */ | |||
| 50 | REDIRECT_SYSCALL(fork)typeof(fork) fork asm("_thread_sys_""fork"); | |||
| 51 | REDIRECT_SYSCALL(vfork)typeof(vfork) vfork asm("_thread_sys_""vfork"); | |||
| 52 | REDIRECT_SYSCALL(getthrid)typeof(getthrid) getthrid asm("_thread_sys_""getthrid"); | |||
| 53 | ||||
| 54 | static pid_t | |||
| 55 | _dofork(pid_t (*sys_fork)(void)) | |||
| 56 | { | |||
| 57 | pthread_t me; | |||
| 58 | pid_t newid; | |||
| 59 | extern int _post_threaded; | |||
| 60 | ||||
| 61 | if (!_threads_ready) | |||
| 62 | return sys_fork(); | |||
| ||||
| 63 | ||||
| 64 | me = pthread_self(); | |||
| 65 | ||||
| 66 | /* | |||
| 67 | * Protect important libc/ld.so critical areas across the fork call. | |||
| 68 | * dlclose() will grab the atexit lock via __cxa_finalize() so lock | |||
| 69 | * the dl_lock first. malloc()/free() can use arc4random(), so lock | |||
| 70 | * malloc_lock before arc4_lock | |||
| 71 | */ | |||
| 72 | ||||
| 73 | #ifndef NO_PIC | |||
| 74 | if (_DYNAMIC) | |||
| 75 | _rthread_dl_lock(0); | |||
| 76 | #endif | |||
| 77 | ||||
| 78 | newid = _thread_dofork(sys_fork); | |||
| 79 | ||||
| 80 | if (newid == 0) { | |||
| 81 | struct tib *tib = me->tib; | |||
| 82 | #ifndef NO_PIC | |||
| 83 | /* reinitialize the lock in the child */ | |||
| 84 | if (_DYNAMIC) | |||
| 85 | _rthread_dl_lock(2); | |||
| 86 | #endif | |||
| 87 | /* update this thread's structure */ | |||
| 88 | tib->tib_tid = getthrid(); | |||
| 89 | me->donesem.lock = _SPINLOCK_UNLOCKED(0); | |||
| 90 | me->flags_lock = _SPINLOCK_UNLOCKED(0); | |||
| 91 | ||||
| 92 | /* reinit the thread list */ | |||
| 93 | LIST_INIT(&_thread_list)do { ((&_thread_list)->lh_first) = ((void*)0); } while (0); | |||
| 94 | LIST_INSERT_HEAD(&_thread_list, me, threads)do { if (((me)->threads.le_next = (&_thread_list)-> lh_first) != ((void*)0)) (&_thread_list)->lh_first-> threads.le_prev = &(me)->threads.le_next; (&_thread_list )->lh_first = (me); (me)->threads.le_prev = &(& _thread_list)->lh_first; } while (0); | |||
| 95 | _thread_lock = _SPINLOCK_UNLOCKED(0); | |||
| 96 | ||||
| 97 | /* single threaded now */ | |||
| 98 | __isthreaded = 0; | |||
| 99 | _post_threaded = 0; /* notyet... */ | |||
| 100 | } | |||
| 101 | #ifndef NO_PIC | |||
| 102 | else if (_DYNAMIC) | |||
| 103 | _rthread_dl_lock(1); | |||
| 104 | #endif | |||
| 105 | return newid; | |||
| 106 | } | |||
| 107 | ||||
| 108 | pid_t | |||
| 109 | _thread_fork(void) | |||
| 110 | { | |||
| 111 | return _dofork(&fork); | |||
| 112 | } | |||
| 113 | ||||
| 114 | pid_t | |||
| 115 | _thread_vfork(void) | |||
| 116 | { | |||
| 117 | return _dofork(&vfork); | |||
| ||||
| 118 | } |