tests/kernel/t_pipe.c

   1 /* $NetBSD:$ */
   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("$NetBSD$");
  33
  34 #include <sys/types.h>
  35 #include <sys/wait.h>
  36
  37 #include <errno.h>
  38 #include <poll.h>
  39 #include <sched.h>
  40 #include <signal.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <unistd.h>
  44
  45 #include <atf-c.h>
  46
  47 #include "../h_macros.h"
  48
  49 static pid_t pid;
  50 static int nsiginfo = 0;
  51
  52 /*
  53  * This is used for both parent and child. Handle parent's SIGALRM,
  54  * the childs SIGINFO doesn't need anything.
  55  */
  56 static void
  57 sighand(int sig)
  58 {
  59         if (sig == SIGALRM) {
  60                 kill(pid, SIGINFO);
  61         }
  62         if (sig == SIGINFO) {
  63                 nsiginfo++;
  64         }
  65 }
  66
  67 ATF_TC(pipe);
  68 ATF_TC_HEAD(pipe, tc)
  69 {
  70         atf_tc_set_md_var(tc, "descr", "Checks that writing to pipe "
  71             "works correctly after being interrupted and restarted "
  72             "(kern/14087)");
  73 }
  74 ATF_TC_BODY(pipe, tc)
  75 {
  76         int pp[2], st;
  77         ssize_t sz, todo, done;
  78         char *f;
  79         sigset_t asigset, osigset, emptysigset;
  80
  81         /* Initialise signal masks */
  82         RL(sigemptyset(&emptysigset));
  83         RL(sigemptyset(&asigset));
  84         RL(sigaddset(&asigset, SIGINFO));
  85
  86         /* Register signal handlers for both read and writer */
  87         REQUIRE_LIBC(signal(SIGINFO, sighand), SIG_ERR);
  88         REQUIRE_LIBC(signal(SIGALRM, sighand), SIG_ERR);
  89
  90         todo = 2 * 1024 * 1024;
  91         REQUIRE_LIBC(f = malloc(todo), NULL);
  92
  93         RL(pipe(pp));
  94
  95         RL(pid = fork());
  96         if (pid == 0) {
  97                 /* child */
  98                 RL(close(pp[1]));
  99
 100                 /* Do inital write. This should succeed, make
 101                  * the other side do partial write and wait for us to pick
 102                  * rest up.
 103                  */
 104                 RL(done = read(pp[0], f, 128 * 1024));
 105
 106                 /* Wait until parent is alarmed and awakens us */
 107                 RL(sigprocmask(SIG_BLOCK, &asigset, &osigset));
 108                 while (nsiginfo == 0) {
 109                         if (sigsuspend(&emptysigset) != -1 || errno != EINTR)
 110                                 atf_tc_fail("sigsuspend(&emptysigset): %s", strerror(errno));
 111                 }
 112                 RL(sigprocmask(SIG_SETMASK, &osigset, NULL));
 113
 114                 /* Read all what parent wants to give us */
 115                 while((sz = read(pp[0], f, 1024 * 1024)) > 0)
 116                         done += sz;
 117
 118                 /*
 119                  * Exit with 1 if number of bytes read doesn't match
 120                  * number of expected bytes
 121                  */
 122                 printf("Read:     %#zx\n", (size_t)done);
 123                 printf("Expected: %#zx\n", (size_t)todo);
 124
 125                 exit(done != todo);
 126
 127                 /* NOTREACHED */
 128         } else {
 129                 RL(close(pp[0]));
 130
 131                 /*
 132                  * Arrange for alarm after two seconds. Since we have
 133                  * handler setup for SIGARLM, the write(2) call should
 134                  * be restarted internally by kernel.
 135                  */
 136                 (void)alarm(2);
 137
 138                 /* We write exactly 'todo' bytes. The very first write(2)
 139                  * should partially succeed, block and eventually
 140                  * be restarted by kernel
 141                  */
 142                 while(todo > 0 && ((sz = write(pp[1], f, todo)) > 0))
 143                         todo -= sz;
 144
 145                 /* Close the pipe, so that child would stop reading */
 146                 RL(close(pp[1]));
 147
 148                 /* And pickup child's exit status */
 149                 RL(waitpid(pid, &st, 0));
 150
 151                 ATF_REQUIRE_EQ(WEXITSTATUS(st), 0);
 152         }
 153 }
 154
 155 ATF_TP_ADD_TCS(tp)
 156 {
 157         ATF_TP_ADD_TC(tp, pipe);
 158
 159         return atf_no_error();
 160 }