1175821Srwatson/*- 2175821Srwatson * Copyright (c) 2008 Robert N. M. Watson 3175821Srwatson * All rights reserved. 4175821Srwatson * 5175821Srwatson * Redistribution and use in source and binary forms, with or without 6175821Srwatson * modification, are permitted provided that the following conditions 7175821Srwatson * are met: 8175821Srwatson * 1. Redistributions of source code must retain the above copyright 9175821Srwatson * notice, this list of conditions and the following disclaimer. 10175821Srwatson * 2. Redistributions in binary form must reproduce the above copyright 11175821Srwatson * notice, this list of conditions and the following disclaimer in the 12175821Srwatson * documentation and/or other materials provided with the distribution. 13175821Srwatson * 14175821Srwatson * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15175821Srwatson * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16175821Srwatson * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17175821Srwatson * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18175821Srwatson * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19175821Srwatson * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20175821Srwatson * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21175821Srwatson * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22175821Srwatson * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23175821Srwatson * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24175821Srwatson * SUCH DAMAGE. 25175821Srwatson */ 26175821Srwatson 27175821Srwatson/* 28175821Srwatson * Reproduce a race in which: 29175821Srwatson * 30175821Srwatson * - Process (a) is blocked in read on a socket waiting on data. 31175821Srwatson * - Process (b) is blocked in shutdown() on a socket waiting on (a). 32175821Srwatson * - Process (c) delivers a signal to (b) interrupting its wait. 33175821Srwatson * 34175821Srwatson * This race is premised on shutdown() not interrupting (a) properly, and the 35175821Srwatson * signal to (b) causing problems in the kernel. 36175821Srwatson */ 37175821Srwatson 38175821Srwatson#include <sys/cdefs.h> 39175821Srwatson__FBSDID("$FreeBSD$"); 40175821Srwatson 41175821Srwatson#include <sys/socket.h> 42175821Srwatson 43175821Srwatson#include <err.h> 44175821Srwatson#include <signal.h> 45175821Srwatson#include <stdio.h> 46175821Srwatson#include <stdlib.h> 47175821Srwatson#include <unistd.h> 48175821Srwatson 49175821Srwatsonstatic void 50175821Srwatsonreceive_and_exit(int s) 51175821Srwatson{ 52175821Srwatson ssize_t ssize; 53175821Srwatson char ch; 54175821Srwatson 55175821Srwatson ssize = recv(s, &ch, sizeof(ch), 0); 56175821Srwatson if (ssize < 0) 57175821Srwatson err(-1, "receive_and_exit: recv"); 58175821Srwatson exit(0); 59175821Srwatson} 60175821Srwatson 61175821Srwatsonstatic void 62175821Srwatsonshutdown_and_exit(int s) 63175821Srwatson{ 64175821Srwatson 65175821Srwatson if (shutdown(s, SHUT_RD) < 0) 66175821Srwatson err(-1, "shutdown_and_exit: shutdown"); 67175821Srwatson exit(0); 68175821Srwatson} 69175821Srwatson 70175821Srwatsonint 71175821Srwatsonmain(int argc, char *argv[]) 72175821Srwatson{ 73175821Srwatson pid_t pida, pidb; 74175821Srwatson int sv[2]; 75175821Srwatson 76175821Srwatson if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sv) < 0) 77175821Srwatson err(-1, "socketpair"); 78175821Srwatson 79175821Srwatson pida = fork(); 80175821Srwatson if (pida < 0) 81175821Srwatson err(-1, "fork"); 82175821Srwatson if (pida == 0) 83175821Srwatson receive_and_exit(sv[1]); 84175821Srwatson sleep(1); 85175821Srwatson pidb = fork(); 86175821Srwatson if (pidb < 0) { 87175821Srwatson warn("fork"); 88175821Srwatson (void)kill(pida, SIGKILL); 89175821Srwatson exit(-1); 90175821Srwatson } 91175821Srwatson if (pidb == 0) 92175821Srwatson shutdown_and_exit(sv[1]); 93175821Srwatson sleep(1); 94175821Srwatson if (kill(pidb, SIGKILL) < 0) 95175821Srwatson err(-1, "kill"); 96175821Srwatson sleep(1); 97175821Srwatson printf("ok 1 - unix_sorflush\n"); 98175821Srwatson exit(0); 99175821Srwatson} 100