t_pipe.c revision 314817 
1/* $NetBSD: t_pipe.c,v 1.5 2017/01/13 21:30:41 christos Exp $ */
2
3/*-
4 * Copyright (c) 2001, 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__COPYRIGHT("@(#) Copyright (c) 2008\
31 The NetBSD Foundation, inc. All rights reserved.");
32__RCSID("$NetBSD: t_pipe.c,v 1.5 2017/01/13 21:30:41 christos Exp $");
33
34#include <sys/types.h>
35#include <sys/wait.h>
36
37#include <errno.h>
38#include <fcntl.h>
39#include <poll.h>
40#include <sched.h>
41#include <signal.h>
42#include <stdio.h>
43#include <stdlib.h>
44#include <unistd.h>
45
46#include <atf-c.h>
47
48#include "h_macros.h"
49
50static pid_t pid;
51static int nsiginfo = 0;
52
53/*
54 * This is used for both parent and child. Handle parent's SIGALRM,
55 * the childs SIGINFO doesn't need anything.
56 */
57static void
58sighand(int sig)
59{
60	if (sig == SIGALRM) {
61		kill(pid, SIGINFO);
62	}
63	if (sig == SIGINFO) {
64		nsiginfo++;
65	}
66}
67
68ATF_TC(pipe_restart);
69ATF_TC_HEAD(pipe_restart, tc)
70{
71	atf_tc_set_md_var(tc, "descr", "Checks that writing to pipe "
72	    "works correctly after being interrupted and restarted "
73	    "(kern/14087)");
74}
75
76ATF_TC_BODY(pipe_restart, tc)
77{
78	int pp[2], st;
79	ssize_t sz, todo, done;
80	char *f;
81	sigset_t asigset, osigset, emptysigset;
82
83	/* Initialise signal masks */
84	RL(sigemptyset(&emptysigset));
85	RL(sigemptyset(&asigset));
86	RL(sigaddset(&asigset, SIGINFO));
87
88	/* Register signal handlers for both read and writer */
89	REQUIRE_LIBC(signal(SIGINFO, sighand), SIG_ERR);
90	REQUIRE_LIBC(signal(SIGALRM, sighand), SIG_ERR);
91
92	todo = 2 * 1024 * 1024;
93	REQUIRE_LIBC(f = malloc(todo), NULL);
94
95	RL(pipe(pp));
96
97	RL(pid = fork());
98	if (pid == 0) {
99		/* child */
100		RL(close(pp[1]));
101
102		/* Do inital write. This should succeed, make
103		 * the other side do partial write and wait for us to pick
104		 * rest up.
105		 */
106		RL(done = read(pp[0], f, 128 * 1024));
107
108		/* Wait until parent is alarmed and awakens us */
109		RL(sigprocmask(SIG_BLOCK, &asigset, &osigset));
110		while (nsiginfo == 0) {
111			if (sigsuspend(&emptysigset) != -1 || errno != EINTR)
112				atf_tc_fail("sigsuspend(&emptysigset): %s",
113				    strerror(errno));
114		}
115		RL(sigprocmask(SIG_SETMASK, &osigset, NULL));
116
117		/* Read all what parent wants to give us */
118		while((sz = read(pp[0], f, 1024 * 1024)) > 0)
119			done += sz;
120
121		/*
122		 * Exit with 1 if number of bytes read doesn't match
123		 * number of expected bytes
124		 */
125		printf("Read:     %#zx\n", (size_t)done);
126		printf("Expected: %#zx\n", (size_t)todo);
127
128		exit(done != todo);
129
130		/* NOTREACHED */
131	} else {
132		RL(close(pp[0]));
133
134		/*
135		 * Arrange for alarm after two seconds. Since we have
136		 * handler setup for SIGARLM, the write(2) call should
137		 * be restarted internally by kernel.
138		 */
139		(void)alarm(2);
140
141		/* We write exactly 'todo' bytes. The very first write(2)
142		 * should partially succeed, block and eventually
143		 * be restarted by kernel
144		 */
145		while(todo > 0 && ((sz = write(pp[1], f, todo)) > 0))
146			todo -= sz;
147
148		/* Close the pipe, so that child would stop reading */
149		RL(close(pp[1]));
150
151		/* And pickup child's exit status */
152		RL(waitpid(pid, &st, 0));
153
154		ATF_REQUIRE_EQ(WEXITSTATUS(st), 0);
155	}
156	free(f);
157}
158
159ATF_TP_ADD_TCS(tp)
160{
161	ATF_TP_ADD_TC(tp, pipe_restart);
162
163	return atf_no_error();
164}
165