Home | History | Annotate | Download | only in mmap
      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  * MPR An implementation may permit accesses other than those specified by prot;
     10  * however, if the Memory Protection option is supported, the implementation
     11  * shall not permit a write to succeed where PROT_WRITE has not been set or
     12  * shall not permit any access where PROT_NONE alone has been set.
     13  * The implementation shall support at least the following values of prot:
     14  * PROT_NONE, PROT_READ, PROT_WRITE, and the bitwise-inclusive OR of PROT_READ
     15  * and PROT_WRITE.
     16  *
     17  * Test Steps:
     18  *
     19  * If Memory Protection option is supported:
     20  * 1. Spawn a child process.
     21  * 2. The child process mmap a memory region setting prot as PROT_READ.
     22  * 3. Try to write the mapped memory.
     23  * 4. If the writing triger SIGSEGV, the PASS.
     24  *
     25  * Please refer to IEEE_1003.1-2001. 2.8.3.3 Memory Protection.
     26  */
     27 
     28 #include <sys/mman.h>
     29 #include <sys/types.h>
     30 #include <sys/stat.h>
     31 #include <sys/wait.h>
     32 #include <errno.h>
     33 #include <fcntl.h>
     34 #include <signal.h>
     35 #include <stdio.h>
     36 #include <stdlib.h>
     37 #include <string.h>
     38 #include <unistd.h>
     39 #include "posixtest.h"
     40 
     41 int main(void)
     42 {
     43 #ifdef _POSIX_MEMORY_PROTECTION
     44 	char tmpfname[256];
     45 	void *pa;
     46 	size_t size = 1024;
     47 	int fd;
     48 
     49 	pid_t child;
     50 	int status;
     51 	int sig_num;
     52 
     53 	snprintf(tmpfname, sizeof(tmpfname), "/tmp/pts_mmap_6_1_%d", getpid());
     54 	unlink(tmpfname);
     55 	fd = open(tmpfname, O_CREAT | O_RDWR | O_EXCL, S_IRUSR | S_IWUSR);
     56 	if (fd == -1) {
     57 		printf("Error at open(): %s\n", strerror(errno));
     58 		return PTS_UNRESOLVED;
     59 	}
     60 	unlink(tmpfname);
     61 
     62 	child = fork();
     63 
     64 	switch (child) {
     65 	case 0:
     66 		if (ftruncate(fd, size) == -1) {
     67 			printf("Error at ftruncate(): %s\n", strerror(errno));
     68 			return PTS_UNRESOLVED;
     69 		}
     70 
     71 		pa = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
     72 		if (pa == MAP_FAILED) {
     73 			printf("Error at mmap: %s\n", strerror(errno));
     74 			return PTS_FAIL;
     75 		}
     76 
     77 		*(char *)pa = 'b';
     78 		return 0;
     79 		break;
     80 	case -1:
     81 		printf("Error at fork(): %s\n", strerror(errno));
     82 		return PTS_UNRESOLVED;
     83 		break;
     84 	default:
     85 		break;
     86 	}
     87 
     88 	waitpid(child, &status, WUNTRACED);
     89 	close(fd);
     90 
     91 	if (WIFSIGNALED(status)) {
     92 		sig_num = WTERMSIG(status);
     93 		printf("Child process terminated by signal %d\n", sig_num);
     94 		if (sig_num == SIGSEGV) {
     95 			printf("Got SIGSEGV when writing to the mapped memory, "
     96 			       "without setting PROT_WRITE\n" "Test PASSED\n");
     97 			return PTS_PASS;
     98 		}
     99 	}
    100 
    101 	if (WIFEXITED(status)) {
    102 		if (WEXITSTATUS(status) == 0) {
    103 			printf
    104 			    ("Did not got SIGSEGV when writing to the mapped memory,"
    105 			     " without setting PROT_WRITE\n" "Test FAILED\n");
    106 			return PTS_FAIL;
    107 		}
    108 	}
    109 
    110 	printf("Test Unresolved\n");
    111 	return PTS_UNRESOLVED;
    112 #else
    113 	printf("Test Unsupported, _POSIX_MEMORY_PROTECTION not defined\n");
    114 	return PTS_UNSUPPORTED;
    115 #endif
    116 }
    117