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      1 /*
      2  * Copyright (c) International Business Machines  Corp., 2001
      3  *
      4  * This program is free software;  you can redistribute it and/or modify
      5  * it under the terms of the GNU General Public License as published by
      6  * the Free Software Foundation; either version 2 of the License, or
      7  * (at your option) any later version.
      8  *
      9  * This program is distributed in the hope that it will be useful,
     10  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
     11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
     12  * the GNU General Public License for more details.
     13  *
     14  * You should have received a copy of the GNU General Public License
     15  * along with this program;  if not, write to the Free Software
     16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     17  */
     18 
     19 /*
     20  * DESCRIPTION
     21  *	Testcase to check the error conditions for mprotect(2)
     22  *
     23  * ALGORITHM
     24  *	test1:
     25  *		Invoke mprotect() with an address of 0. Check if error
     26  *		is set to ENOMEM.
     27  *	test2:
     28  *		Invoke mprotect() with an address that is not a multiple
     29  *		of PAGESIZE.  EINVAL
     30  *	test3:
     31  *		Mmap a file with only read permission (PROT_READ).
     32  *		Try to set write permission (PROT_WRITE) using mprotect(2).
     33  *		Check that error is set to EACCES.
     34  *
     35  * HISTORY
     36  *	07/2001 Ported by Wayne Boyer
     37  *	03/2002 Paul Larson: case 1 should expect ENOMEM not EFAULT
     38  */
     39 
     40 #include <fcntl.h>
     41 #include <errno.h>
     42 #include <sys/mman.h>
     43 #include <stdlib.h>
     44 #include <unistd.h>
     45 #include "test.h"
     46 
     47 char *TCID = "mprotect01";
     48 int TST_TOTAL = 3;
     49 
     50 struct test_case {
     51 	void *addr;
     52 	int len;
     53 	int prot;
     54 	int error;
     55 	void (*setupfunc) (struct test_case *self);
     56 };
     57 
     58 static void cleanup(void);
     59 static void setup(void);
     60 static void setup1(struct test_case *self);
     61 static void setup2(struct test_case *self);
     62 static void setup3(struct test_case *self);
     63 
     64 static int fd;
     65 
     66 struct test_case TC[] = {
     67 	/* Check for ENOMEM passing memory that cannot be accessed. */
     68 	{NULL, 0, PROT_READ, ENOMEM, setup1},
     69 
     70 	/*
     71 	 * Check for EINVAL by passing a pointer which is not a
     72 	 * multiple of PAGESIZE.
     73 	 */
     74 	{NULL, 1024, PROT_READ, EINVAL, setup2},
     75 	/*
     76 	 * Check for EACCES by trying to mark a section of memory
     77 	 * which has been mmap'ed as read-only, as PROT_WRITE
     78 	 */
     79 	{NULL, 0, PROT_WRITE, EACCES, setup3}
     80 };
     81 
     82 int main(int ac, char **av)
     83 {
     84 	int lc;
     85 	int i;
     86 
     87 	tst_parse_opts(ac, av, NULL, NULL);
     88 
     89 	setup();
     90 
     91 	for (lc = 0; TEST_LOOPING(lc); lc++) {
     92 		tst_count = 0;
     93 
     94 		for (i = 0; i < TST_TOTAL; i++) {
     95 
     96 			if (TC[i].setupfunc != NULL)
     97 				TC[i].setupfunc(&TC[i]);
     98 
     99 			TEST(mprotect(TC[i].addr, TC[i].len, TC[i].prot));
    100 
    101 			if (TEST_RETURN != -1) {
    102 				tst_resm(TFAIL, "call succeeded unexpectedly");
    103 				continue;
    104 			}
    105 
    106 			if (TEST_ERRNO == TC[i].error) {
    107 				tst_resm(TPASS, "expected failure - "
    108 					 "errno = %d : %s", TEST_ERRNO,
    109 					 strerror(TEST_ERRNO));
    110 			} else {
    111 				tst_resm(TFAIL, "unexpected error - %d : %s - "
    112 					 "expected %d", TEST_ERRNO,
    113 					 strerror(TEST_ERRNO), TC[i].error);
    114 			}
    115 		}
    116 	}
    117 	cleanup();
    118 	tst_exit();
    119 }
    120 
    121 static void setup1(struct test_case *self)
    122 {
    123 	self->len = getpagesize() + 1;
    124 }
    125 
    126 static void setup2(struct test_case *self)
    127 {
    128 	self->addr = malloc(getpagesize());
    129 
    130 	if (self->addr == NULL)
    131 		tst_brkm(TINFO, cleanup, "malloc failed");
    132 
    133 	/* Ensure addr2 is not page aligned */
    134 	self->addr++;
    135 }
    136 
    137 static void setup3(struct test_case *self)
    138 {
    139 	fd = open("/etc/passwd", O_RDONLY);
    140 	if (fd < 0)
    141 		tst_brkm(TBROK, cleanup, "open failed");
    142 
    143 	self->len = getpagesize();
    144 
    145 	/*
    146 	 * mmap the PAGESIZE bytes as read only.
    147 	 */
    148 	self->addr = mmap(0, self->len, PROT_READ, MAP_SHARED, fd, 0);
    149 	if (self->addr == MAP_FAILED)
    150 		tst_brkm(TBROK, cleanup, "mmap failed");
    151 
    152 }
    153 
    154 static void setup(void)
    155 {
    156 	tst_sig(FORK, DEF_HANDLER, cleanup);
    157 
    158 	TEST_PAUSE;
    159 }
    160 
    161 static void cleanup(void)
    162 {
    163 	close(fd);
    164 }
    165