1 /*
2  * Copyright (c) 2017 Cyril Hrubis <chrubis@suse.cz>
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 the
12  * 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, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <unistd.h>
19 #include <stdint.h>
20 #include <inttypes.h>
21 #include <errno.h>
22 
23 #include "tst_test.h"
24 
25 void verify_brk(void)
26 {
27 	uintptr_t cur_brk, new_brk;
28 	uintptr_t inc = getpagesize() * 2 - 1;
29 	unsigned int i;
30 
31 	cur_brk = (uintptr_t)sbrk(0);
32 
33 	for (i = 0; i < 33; i++) {
34 		switch (i % 3) {
35 		case 0:
36 			new_brk = cur_brk + inc;
37 		break;
38 		case 1:
39 			new_brk = cur_brk;
40 		break;
41 		case 2:
42 			new_brk = cur_brk - inc;
43 		break;
44 		}
45 
46 		TEST(brk((void *)new_brk));
47 
48 		if (TEST_RETURN == -1) {
49 			tst_res(TFAIL | TERRNO, "brk() failed");
50 			return;
51 		}
52 
53 		cur_brk = (uintptr_t)sbrk(0);
54 
55 		if (cur_brk != new_brk) {
56 			tst_res(TFAIL,
57 				"brk() failed to set address have %p expected %p",
58 				(void *)cur_brk, (void *)new_brk);
59 			return;
60 		}
61 
62 		/* Try to write to the newly allocated heap */
63 		if (i % 3 == 0)
64 			*((char *)cur_brk) = 0;
65 	}
66 
67 	tst_res(TPASS, "brk() works fine");
68 }
69 
70 static struct tst_test test = {
71 	.test_all = verify_brk,
72 };
73