1/* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License version 2. 4 * 5 * This program is distributed in the hope that it will be useful, 6 * but WITHOUT ANY WARRANTY; without even the implied warranty of 7 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 8 * GNU General Public License for more details. 9 * 10 * Test that shm_open does not open the shared memory object for writing when 11 * calling shm_open with O_RDONLY even if the mode set write permission. 12 * 13 * The test use ftruncate to check the object is not open for writing. 14 */ 15 16/* ftruncate was formerly an XOPEN extension. We define _XOPEN_SOURCE here to 17 avoid warning if the implementation does not program ftruncate as a base 18 interface */ 19#define _XOPEN_SOURCE 600 20 21#include <stdio.h> 22#include <sys/mman.h> 23#include <sys/stat.h> 24#include <unistd.h> 25#include <fcntl.h> 26#include <errno.h> 27#include "posixtest.h" 28 29#define BUF_SIZE 8 30#define SHM_NAME "posixtest_20-1" 31 32int main() { 33 int fd, result; 34 35 result = shm_unlink(SHM_NAME); 36 if(result != 0 && errno != ENOENT) { 37 /* The shared memory object exist and shm_unlink can not 38 remove it. */ 39 perror("An error occurs when calling shm_unlink()"); 40 return PTS_UNRESOLVED; 41 } 42 43 fd = shm_open(SHM_NAME, O_RDONLY|O_CREAT, S_IRUSR); 44 if(fd == -1) { 45 perror("An error occurs when calling shm_open()"); 46 return PTS_UNRESOLVED; 47 } 48 49 result = ftruncate(fd, BUF_SIZE); 50 51 if(result == -1 && errno == EINVAL) { 52 printf("Test PASSED\n"); 53 shm_unlink(SHM_NAME); 54 return PTS_PASS; 55 } else if(result == 0){ 56 printf("The shared memory object is opened for writing.\n"); 57 shm_unlink(SHM_NAME); 58 return PTS_FAIL; 59 } 60 61 perror("ftruncate"); 62 shm_unlink(SHM_NAME); 63 return PTS_FAIL; 64} 65