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