1 /* 2 * Copyright (c) 2002, Intel Corporation. All rights reserved. 3 * Copyright (c) 2012, Cyril Hrubis <chrubis (at) suse.cz> 4 * 5 * This file is licensed under the GPL license. For the full content 6 * of this license, see the COPYING file at the top level of this 7 * source tree. 8 * 9 * Implementation performs mapping operations over whole pages. 10 * Thus, while the argument len 11 * need not meet a size or alignment constraint, 12 * the implementation shall include, in any mapping 13 * operation, any partial page specified by the range [pa,pa+len). 14 * The system shall always zero-fill any partial page at the end of an object. 15 * Further, the system shall never write out any modified portions of 16 * the last page of an object which are beyond its end. 17 * 18 * Test Steps: 19 * 1. Create a process, in this process: 20 * a. map a file with size of 1/2 * page_size, 21 * set len = 1/2 * page_size 22 * b. Read the partial page beyond the object size. 23 * Make sure the partial page is zero-filled; 24 * c. Modify a byte in the partial page, then un-map the and close the 25 * file descriptor. 26 * 2. Wait for the child proces to exit, then 27 * Map the file again, 28 * read the byte from the position modified at step 1-c and check. 29 */ 30 31 32 #include <stdio.h> 33 #include <stdlib.h> 34 #include <unistd.h> 35 #include <sys/mman.h> 36 #include <sys/types.h> 37 #include <sys/stat.h> 38 #include <sys/wait.h> 39 #include <fcntl.h> 40 #include <string.h> 41 #include <errno.h> 42 #include <sys/vfs.h> 43 #include "posixtest.h" 44 45 #define TYPE_TMPFS_MAGIC 0x01021994 46 47 int main(void) 48 { 49 char tmpfname[256]; 50 long page_size; 51 52 char *pa; 53 size_t len; 54 int fd; 55 56 pid_t child; 57 int i, exit_val; 58 59 struct statfs buf; 60 61 page_size = sysconf(_SC_PAGE_SIZE); 62 63 /* mmap will create a partial page */ 64 len = page_size / 2; 65 66 if (statfs("/tmp", &buf)) { 67 printf("Error at statfs(): %s\n", strerror(errno)); 68 return PTS_UNRESOLVED; 69 } 70 71 if (buf.f_type == TYPE_TMPFS_MAGIC) { 72 printf("From mmap(2) manpage, skip known bug on tmpfs\n"); 73 return PTS_UNTESTED; 74 } 75 76 snprintf(tmpfname, sizeof(tmpfname), "/tmp/pts_mmap_11_5_%d", getpid()); 77 child = fork(); 78 switch (child) { 79 case 0: 80 /* Create shared object */ 81 unlink(tmpfname); 82 fd = open(tmpfname, O_CREAT | O_RDWR | O_EXCL, 83 S_IRUSR | S_IWUSR); 84 if (fd == -1) { 85 printf("Error at open(): %s\n", strerror(errno)); 86 return PTS_UNRESOLVED; 87 } 88 if (ftruncate(fd, len) == -1) { 89 printf("Error at ftruncate(): %s\n", strerror(errno)); 90 return PTS_UNRESOLVED; 91 } 92 93 pa = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); 94 if (pa == MAP_FAILED) { 95 printf("Error at mmap(): %s\n", strerror(errno)); 96 return PTS_FAIL; 97 } 98 99 /* Check the patial page is ZERO filled */ 100 for (i = len; i < page_size; i++) 101 if (pa[i] != 0) { 102 printf("Test FAILED: The partial page at the " 103 "end of an object is not zero-filled\n"); 104 return PTS_FAIL; 105 } 106 107 /* Write the partial page */ 108 pa[len + 1] = 'b'; 109 msync(pa, len, MS_SYNC); 110 munmap(pa, len); 111 close(fd); 112 return PTS_PASS; 113 case -1: 114 printf("Error at fork(): %s\n", strerror(errno)); 115 return PTS_UNRESOLVED; 116 default: 117 break; 118 } 119 120 wait(&exit_val); 121 if (!(WIFEXITED(exit_val) && (WEXITSTATUS(exit_val) == PTS_PASS))) { 122 unlink(tmpfname); 123 124 if (WIFEXITED(exit_val)) 125 return WEXITSTATUS(exit_val); 126 127 printf("Child exited abnormally\n"); 128 return PTS_UNRESOLVED; 129 } 130 131 fd = open(tmpfname, O_RDWR, 0); 132 unlink(tmpfname); 133 134 pa = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); 135 if (pa == MAP_FAILED) { 136 printf("Error at 2nd mmap(): %s\n", strerror(errno)); 137 return PTS_FAIL; 138 } 139 140 if (pa[len + 1] == 'b') { 141 printf("Test FAILED: Modification of the partial page " 142 "at the end of an object is written out\n"); 143 return PTS_FAIL; 144 } 145 close(fd); 146 munmap(pa, len); 147 148 printf("Test PASSED\n"); 149 return PTS_PASS; 150 } 151
