xref: /freebsd/lib/libc/tests/sys/brk_test.c (revision 9f44a47fd07924afc035991af15d84e6585dea4f)
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 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/mman.h>
33 
34 #include <errno.h>
35 #include <stdint.h>
36 #include <string.h>
37 #include <unistd.h>
38 
39 #include <atf-c.h>
40 
41 ATF_TC(brk_basic);
42 ATF_TC_HEAD(brk_basic, tc)
43 {
44 	atf_tc_set_md_var(tc, "descr", "Verify basic brk() functionality");
45 }
46 ATF_TC_BODY(brk_basic, tc)
47 {
48 	void *oldbrk, *newbrk;
49 	int error;
50 
51 	/* Reset the break. */
52 	error = brk(0);
53 	ATF_REQUIRE_MSG(error == 0, "brk: %s", strerror(errno));
54 
55 	oldbrk = sbrk(0);
56 	ATF_REQUIRE(oldbrk != (void *)-1);
57 
58 	/* Try to allocate a page. */
59 	error = brk((void *)((intptr_t)oldbrk + PAGE_SIZE * 2));
60 	ATF_REQUIRE_MSG(error == 0, "brk: %s", strerror(errno));
61 
62 	/*
63 	 * Attempt to set the break below minbrk.  This should have no effect.
64 	 */
65 	error = brk((void *)((intptr_t)oldbrk - 1));
66 	ATF_REQUIRE_MSG(error == 0, "brk: %s", strerror(errno));
67 	newbrk = sbrk(0);
68 	ATF_REQUIRE_MSG(newbrk != (void *)-1, "sbrk: %s", strerror(errno));
69 	ATF_REQUIRE(newbrk == oldbrk);
70 }
71 
72 ATF_TC(sbrk_basic);
73 ATF_TC_HEAD(sbrk_basic, tc)
74 {
75 	atf_tc_set_md_var(tc, "descr", "Verify basic sbrk() functionality");
76 }
77 ATF_TC_BODY(sbrk_basic, tc)
78 {
79 	void *newbrk, *oldbrk;
80 	int *p;
81 
82 	oldbrk = sbrk(0);
83 	ATF_REQUIRE_MSG(oldbrk != (void *)-1, "sbrk: %s", strerror(errno));
84 	p = sbrk(sizeof(*p));
85 	*p = 0;
86 	ATF_REQUIRE(oldbrk == p);
87 
88 	newbrk = sbrk(-sizeof(*p));
89 	ATF_REQUIRE_MSG(newbrk != (void *)-1, "sbrk: %s", strerror(errno));
90 	ATF_REQUIRE(oldbrk == sbrk(0));
91 
92 	oldbrk = sbrk(PAGE_SIZE * 2 + 1);
93 	ATF_REQUIRE_MSG(oldbrk != (void *)-1, "sbrk: %s", strerror(errno));
94 	memset(oldbrk, 0, PAGE_SIZE * 2 + 1);
95 	newbrk = sbrk(-(PAGE_SIZE * 2 + 1));
96 	ATF_REQUIRE_MSG(newbrk != (void *)-1, "sbrk: %s", strerror(errno));
97 	ATF_REQUIRE(sbrk(0) == oldbrk);
98 }
99 
100 ATF_TC(mlockfuture);
101 ATF_TC_HEAD(mlockfuture, tc)
102 {
103 	atf_tc_set_md_var(tc, "descr",
104 	    "Verify that mlockall(MCL_FUTURE) applies to the data segment");
105 }
106 ATF_TC_BODY(mlockfuture, tc)
107 {
108 	void *oldbrk, *n, *newbrk;
109 	int error;
110 	char v;
111 
112 	error = mlockall(MCL_FUTURE);
113 	ATF_REQUIRE_MSG(error == 0,
114 	    "mlockall: %s", strerror(errno));
115 
116 	/*
117 	 * Advance the break so that at least one page is added to the data
118 	 * segment.  This page should be automatically faulted in to the address
119 	 * space.
120 	 */
121 	oldbrk = sbrk(0);
122 	ATF_REQUIRE(oldbrk != (void *)-1);
123 	newbrk = sbrk(PAGE_SIZE * 2);
124 	ATF_REQUIRE(newbrk != (void *)-1);
125 
126 	n = (void *)(((uintptr_t)oldbrk + PAGE_SIZE) & ~PAGE_SIZE);
127 	v = 0;
128 	error = mincore(n, PAGE_SIZE, &v);
129 	ATF_REQUIRE_MSG(error == 0,
130 	    "mincore: %s", strerror(errno));
131 	ATF_REQUIRE_MSG((v & MINCORE_INCORE) != 0,
132 	    "unexpected page flags %#x", v);
133 
134 	error = brk(oldbrk);
135 	ATF_REQUIRE(error == 0);
136 
137 	error = munlockall();
138 	ATF_REQUIRE_MSG(error == 0,
139 	    "munlockall: %s", strerror(errno));
140 }
141 
142 ATF_TP_ADD_TCS(tp)
143 {
144 	ATF_TP_ADD_TC(tp, brk_basic);
145 	ATF_TP_ADD_TC(tp, sbrk_basic);
146 	ATF_TP_ADD_TC(tp, mlockfuture);
147 
148 	return (atf_no_error());
149 }
150