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 28 #include <unistd.h> 29 #include <fcntl.h> 30 #include <stdio.h> 31 #include <stdlib.h> 32 #include <sys/mman.h> 33 #include <pthread.h> 34 35 /* 36 * -------------------------------------------------------------------- 37 * Bug Id: 5032643 38 * 39 * Simply writing to a file and mmaping that file at the same time can 40 * result in deadlock. Nothing perverse like writing from the file's 41 * own mapping is required. 42 * -------------------------------------------------------------------- 43 */ 44 45 static void * 46 mapper(void *fdp) 47 { 48 void *addr; 49 int fd = *(int *)fdp; 50 51 if ((addr = 52 mmap(0, 8192, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) { 53 perror("mmap"); 54 exit(1); 55 } 56 for (;;) { 57 if (mmap(addr, 8192, PROT_READ, 58 MAP_SHARED|MAP_FIXED, fd, 0) == MAP_FAILED) { 59 perror("mmap"); 60 exit(1); 61 } 62 } 63 /* NOTREACHED */ 64 return ((void *)1); 65 } 66 67 int 68 main(int argc, char **argv) 69 { 70 int fd; 71 char buf[BUFSIZ]; 72 pthread_t pt; 73 74 if (argc != 2) { 75 (void) printf("usage: %s <file name>\n", argv[0]); 76 exit(1); 77 } 78 79 if ((fd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0666)) == -1) { 80 perror("open"); 81 exit(1); 82 } 83 84 if (pthread_create(&pt, NULL, mapper, &fd) != 0) { 85 perror("pthread_create"); 86 exit(1); 87 } 88 for (;;) { 89 if (write(fd, buf, sizeof (buf)) == -1) { 90 perror("write"); 91 exit(1); 92 } 93 } 94 95 /* NOTREACHED */ 96 return (0); 97 } 98