xref: /freebsd/lib/libc/tests/sys/brk_test.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2018 Mark Johnston <markj@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 #include <sys/param.h>
30 #include <sys/mman.h>
31 
32 #include <errno.h>
33 #include <stdint.h>
34 #include <string.h>
35 #include <unistd.h>
36 
37 #include <atf-c.h>
38 
39 ATF_TC(brk_basic);
40 ATF_TC_HEAD(brk_basic, tc)
41 {
42 	atf_tc_set_md_var(tc, "descr", "Verify basic brk() functionality");
43 }
44 ATF_TC_BODY(brk_basic, tc)
45 {
46 	void *oldbrk, *newbrk;
47 	int error;
48 
49 	/* Reset the break. */
50 	error = brk(0);
51 	ATF_REQUIRE_MSG(error == 0, "brk: %s", strerror(errno));
52 
53 	oldbrk = sbrk(0);
54 	ATF_REQUIRE(oldbrk != (void *)-1);
55 
56 	/* Try to allocate a page. */
57 	error = brk((void *)((intptr_t)oldbrk + PAGE_SIZE * 2));
58 	ATF_REQUIRE_MSG(error == 0, "brk: %s", strerror(errno));
59 
60 	/*
61 	 * Attempt to set the break below minbrk.  This should have no effect.
62 	 */
63 	error = brk((void *)((intptr_t)oldbrk - 1));
64 	ATF_REQUIRE_MSG(error == 0, "brk: %s", strerror(errno));
65 	newbrk = sbrk(0);
66 	ATF_REQUIRE_MSG(newbrk != (void *)-1, "sbrk: %s", strerror(errno));
67 	ATF_REQUIRE(newbrk == oldbrk);
68 }
69 
70 ATF_TC(sbrk_basic);
71 ATF_TC_HEAD(sbrk_basic, tc)
72 {
73 	atf_tc_set_md_var(tc, "descr", "Verify basic sbrk() functionality");
74 }
75 ATF_TC_BODY(sbrk_basic, tc)
76 {
77 	void *newbrk, *oldbrk;
78 	int *p;
79 
80 	oldbrk = sbrk(0);
81 	ATF_REQUIRE_MSG(oldbrk != (void *)-1, "sbrk: %s", strerror(errno));
82 	p = sbrk(sizeof(*p));
83 	*p = 0;
84 	ATF_REQUIRE(oldbrk == p);
85 
86 	newbrk = sbrk(-sizeof(*p));
87 	ATF_REQUIRE_MSG(newbrk != (void *)-1, "sbrk: %s", strerror(errno));
88 	ATF_REQUIRE(oldbrk == sbrk(0));
89 
90 	oldbrk = sbrk(PAGE_SIZE * 2 + 1);
91 	ATF_REQUIRE_MSG(oldbrk != (void *)-1, "sbrk: %s", strerror(errno));
92 	memset(oldbrk, 0, PAGE_SIZE * 2 + 1);
93 	newbrk = sbrk(-(PAGE_SIZE * 2 + 1));
94 	ATF_REQUIRE_MSG(newbrk != (void *)-1, "sbrk: %s", strerror(errno));
95 	ATF_REQUIRE(sbrk(0) == oldbrk);
96 }
97 
98 ATF_TC(mlockfuture);
99 ATF_TC_HEAD(mlockfuture, tc)
100 {
101 	atf_tc_set_md_var(tc, "descr",
102 	    "Verify that mlockall(MCL_FUTURE) applies to the data segment");
103 }
104 ATF_TC_BODY(mlockfuture, tc)
105 {
106 	void *oldbrk, *n, *newbrk;
107 	int error;
108 	char v;
109 
110 	error = mlockall(MCL_FUTURE);
111 	ATF_REQUIRE_MSG(error == 0,
112 	    "mlockall: %s", strerror(errno));
113 
114 	/*
115 	 * Advance the break so that at least one page is added to the data
116 	 * segment.  This page should be automatically faulted in to the address
117 	 * space.
118 	 */
119 	oldbrk = sbrk(0);
120 	ATF_REQUIRE(oldbrk != (void *)-1);
121 	newbrk = sbrk(PAGE_SIZE * 2);
122 	ATF_REQUIRE(newbrk != (void *)-1);
123 
124 	n = (void *)(((uintptr_t)oldbrk + PAGE_SIZE) & ~PAGE_SIZE);
125 	v = 0;
126 	error = mincore(n, PAGE_SIZE, &v);
127 	ATF_REQUIRE_MSG(error == 0,
128 	    "mincore: %s", strerror(errno));
129 	ATF_REQUIRE_MSG((v & MINCORE_INCORE) != 0,
130 	    "unexpected page flags %#x", v);
131 
132 	error = brk(oldbrk);
133 	ATF_REQUIRE(error == 0);
134 
135 	error = munlockall();
136 	ATF_REQUIRE_MSG(error == 0,
137 	    "munlockall: %s", strerror(errno));
138 }
139 
140 ATF_TP_ADD_TCS(tp)
141 {
142 	ATF_TP_ADD_TC(tp, brk_basic);
143 	ATF_TP_ADD_TC(tp, sbrk_basic);
144 	ATF_TP_ADD_TC(tp, mlockfuture);
145 
146 	return (atf_no_error());
147 }
148