Home | History | Annotate | Line # | Download | only in sys 
      1 /* $NetBSD: t_pipe.c,v 1.7 2020/06/26 07:50:11 jruoho 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 1.7 2020/06/26 07:50:11 jruoho 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 
     50 static pid_t pid;
     51 static 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  */
     57 static void
     58 sighand(int sig)
     59 {
     60 	if (sig == SIGALRM) {
     61 		kill(pid, SIGINFO);
     62 	}
     63 	if (sig == SIGINFO) {
     64 		nsiginfo++;
     65 	}
     66 }
     67 
     68 ATF_TC(pipe_restart);
     69 ATF_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 	    "(PR kern/14087)");
     74 }
     75 
     76 ATF_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 initial 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 
    159 ATF_TP_ADD_TCS(tp)
    160 {
    161 	ATF_TP_ADD_TC(tp, pipe_restart);
    162 
    163 	return atf_no_error();
    164 }
    165