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      1 /*
      2  * Copyright (c) 2002, Intel Corporation. All rights reserved.
      3  * This file is licensed under the GPL license.  For the full content
      4  * of this license, see the COPYING file at the top level of this
      5  * source tree.
      6  *
      7  * The munmap() function shall remove any mappings for those
      8  * entire pages containing any part of the address space of
      9  * the process starting at addr and continuing for len bytes.
     10  * Further references to these pages shall result in the
     11  * generation of a SIGSEGV signal to the process.
     12  *
     13  * Test Step:
     14  * 1. map a file into memory;
     15  * 2. unmap;
     16  * 3. Try to reference the unmapped memory, test whether SIGSEGV
     17  *    is triggered.
     18  */
     19 
     20 
     21 #include <sys/mman.h>
     22 #include <sys/types.h>
     23 #include <sys/stat.h>
     24 #include <sys/wait.h>
     25 #include <errno.h>
     26 #include <fcntl.h>
     27 #include <pthread.h>
     28 #include <signal.h>
     29 #include <stdio.h>
     30 #include <stdlib.h>
     31 #include <string.h>
     32 #include <unistd.h>
     33 #include "posixtest.h"
     34 
     35 #define TNAME "munmap/1-2.c"
     36 
     37 void sigsegv_handler(int signum)
     38 {
     39 	printf("Got SIGSEGV\n");
     40 	printf("Test PASSED\n");
     41 	exit(PTS_PASS);
     42 }
     43 
     44 int main(void)
     45 {
     46 	char tmpfname[256];
     47 	long file_size;
     48 
     49 	void *pa = NULL;
     50 	void *addr = NULL;
     51 	size_t len;
     52 	int flag;
     53 	int fd;
     54 	off_t off = 0;
     55 	int prot;
     56 
     57 	int page_size;
     58 
     59 	char *ch;
     60 
     61 	struct sigaction sa;
     62 
     63 	sigfillset(&sa.sa_mask);
     64 	sa.sa_handler = sigsegv_handler;
     65 	sigaction(SIGSEGV, &sa, NULL);
     66 
     67 	page_size = sysconf(_SC_PAGE_SIZE);
     68 	file_size = 2 * page_size;
     69 
     70 	/* We hope to map 2 pages */
     71 	len = page_size + 1;
     72 
     73 	/* Create tmp file */
     74 	snprintf(tmpfname, sizeof(tmpfname), "/tmp/pts_munmap_1_1_%d",
     75 		 getpid());
     76 	unlink(tmpfname);
     77 	fd = open(tmpfname, O_CREAT | O_RDWR | O_EXCL, S_IRUSR | S_IWUSR);
     78 	if (fd == -1) {
     79 		printf(TNAME " Error at open(): %s\n", strerror(errno));
     80 		exit(PTS_UNRESOLVED);
     81 	}
     82 	unlink(tmpfname);
     83 
     84 	if (ftruncate(fd, file_size) == -1) {
     85 		printf("Error at ftruncate: %s\n", strerror(errno));
     86 		exit(PTS_UNRESOLVED);
     87 	}
     88 
     89 	flag = MAP_SHARED;
     90 	prot = PROT_READ | PROT_WRITE;
     91 	pa = mmap(addr, len, prot, flag, fd, off);
     92 	if (pa == MAP_FAILED) {
     93 		printf("Test UNRESOLVED: " TNAME " Error at mmap: %s\n",
     94 		       strerror(errno));
     95 		exit(PTS_UNRESOLVED);
     96 	}
     97 
     98 	ch = pa;
     99 	*ch = 'b';
    100 
    101 	close(fd);
    102 	munmap(pa, len);
    103 
    104 	/* Should trigger SIGSEGV here */
    105 	*ch = 'a';
    106 
    107 	printf("Test FAILED: Did not trigger SIGSEGV\n");
    108 	return PTS_FAIL;
    109 }
    110