1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2017 Cyril Hrubis <[email protected]>
4 */
5
6 #include <unistd.h>
7 #include <stdint.h>
8 #include <inttypes.h>
9 #include <errno.h>
10
11 #include "tst_test.h"
12 #include "lapi/syscalls.h"
13
verify_brk(void)14 static void verify_brk(void)
15 {
16 void *cur_brk, *new_brk;
17 size_t inc = getpagesize() * 2 - 1;
18 unsigned int i;
19
20 if (tst_variant) {
21 tst_res(TINFO, "Testing syscall variant");
22 cur_brk = (void *)tst_syscall(__NR_brk, 0);
23 } else {
24 tst_res(TINFO, "Testing libc variant");
25 cur_brk = (void *)sbrk(0);
26
27 if (cur_brk == (void *)-1)
28 tst_brk(TCONF, "sbrk() not implemented");
29
30 /*
31 * Check if brk itself is implemented: updating to the current break
32 * should be a no-op.
33 */
34 if (brk(cur_brk) != 0)
35 tst_brk(TCONF, "brk() not implemented");
36 }
37
38 for (i = 0; i < 33; i++) {
39 switch (i % 3) {
40 case 0:
41 new_brk = cur_brk + inc;
42 break;
43 case 1:
44 new_brk = cur_brk;
45 break;
46 case 2:
47 new_brk = cur_brk - inc;
48 break;
49 }
50
51 if (tst_variant) {
52 cur_brk = (void *)tst_syscall(__NR_brk, new_brk);
53 } else {
54 TST_EXP_PASS_SILENT(brk(new_brk), "brk()");
55 cur_brk = sbrk(0);
56 }
57
58 if (cur_brk != new_brk) {
59 tst_res(TFAIL,
60 "brk() failed to set address have %p expected %p",
61 cur_brk, new_brk);
62 return;
63 }
64
65 /* Try to write to the newly allocated heap */
66 if (i % 3 == 0)
67 *((char *)cur_brk) = 0;
68 }
69
70 tst_res(TPASS, "brk() works fine");
71 }
72
73 static struct tst_test test = {
74 .test_all = verify_brk,
75 .test_variants = 2,
76 };
77