100 lines
2.6 KiB
C
100 lines
2.6 KiB
C
/*-
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* Copyright (c) 2008 Robert N. M. Watson
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* Reproduce a race in which:
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*
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* - Process (a) is blocked in read on a socket waiting on data.
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* - Process (b) is blocked in shutdown() on a socket waiting on (a).
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* - Process (c) delivers a signal to (b) interrupting its wait.
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*
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* This race is premised on shutdown() not interrupting (a) properly, and the
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* signal to (b) causing problems in the kernel.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/socket.h>
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#include <err.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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static void
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receive_and_exit(int s)
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{
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ssize_t ssize;
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char ch;
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ssize = recv(s, &ch, sizeof(ch), 0);
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if (ssize < 0)
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err(-1, "receive_and_exit: recv");
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exit(0);
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}
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static void
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shutdown_and_exit(int s)
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{
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if (shutdown(s, SHUT_RD) < 0)
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err(-1, "shutdown_and_exit: shutdown");
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exit(0);
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}
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int
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main(void)
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{
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pid_t pida, pidb;
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int sv[2];
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if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sv) < 0)
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err(-1, "socketpair");
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pida = fork();
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if (pida < 0)
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err(-1, "fork");
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if (pida == 0)
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receive_and_exit(sv[1]);
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sleep(1);
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pidb = fork();
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if (pidb < 0) {
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warn("fork");
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(void)kill(pida, SIGKILL);
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exit(-1);
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}
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if (pidb == 0)
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shutdown_and_exit(sv[1]);
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sleep(1);
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if (kill(pidb, SIGKILL) < 0)
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err(-1, "kill");
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sleep(1);
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printf("ok 1 - unix_sorflush\n");
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exit(0);
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}
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