1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #include <unistd.h> 28 #include <fcntl.h> 29 #include <stdio.h> 30 #include <stdlib.h> 31 #include <sys/mman.h> 32 #include <pthread.h> 33 34 /* 35 * -------------------------------------------------------------------- 36 * Bug Id: 5032643 37 * 38 * Simply writing to a file and mmaping that file at the same time can 39 * result in deadlock. Nothing perverse like writing from the file's 40 * own mapping is required. 41 * -------------------------------------------------------------------- 42 */ 43 44 static void * 45 mapper(void *fdp) 46 { 47 void *addr; 48 int fd = *(int *)fdp; 49 50 if ((addr = 51 mmap(0, 8192, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) { 52 perror("mmap"); 53 exit(1); 54 } 55 for (;;) { 56 if (mmap(addr, 8192, PROT_READ, 57 MAP_SHARED|MAP_FIXED, fd, 0) == MAP_FAILED) { 58 perror("mmap"); 59 exit(1); 60 } 61 } 62 /* NOTREACHED */ 63 return ((void *)1); 64 } 65 66 int 67 main(int argc, char **argv) 68 { 69 int fd; 70 char buf[BUFSIZ]; 71 72 if (argc != 2) { 73 (void) printf("usage: %s <file name>\n", argv[0]); 74 exit(1); 75 } 76 77 if ((fd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0666)) == -1) { 78 perror("open"); 79 exit(1); 80 } 81 82 if (pthread_create(NULL, NULL, mapper, &fd) != 0) { 83 perror("pthread_create"); 84 exit(1); 85 } 86 for (;;) { 87 if (write(fd, buf, sizeof (buf)) == -1) { 88 perror("write"); 89 exit(1); 90 } 91 } 92 93 /* NOTREACHED */ 94 return (0); 95 } 96