xref: /freebsd/lib/libc/tests/sys/brk_test.c (revision 397e83df75e0fcd0d3fcb95ae4d794cb7600fc89)
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/param.h>
29 #include <sys/mman.h>
30 
31 #include <errno.h>
32 #include <stdint.h>
33 #include <string.h>
34 #include <unistd.h>
35 
36 #include <atf-c.h>
37 
38 ATF_TC(brk_basic);
39 ATF_TC_HEAD(brk_basic, tc)
40 {
41 	atf_tc_set_md_var(tc, "descr", "Verify basic brk() functionality");
42 }
43 ATF_TC_BODY(brk_basic, tc)
44 {
45 	void *oldbrk, *newbrk;
46 	int error;
47 
48 	/* Reset the break. */
49 	error = brk(0);
50 	ATF_REQUIRE_MSG(error == 0, "brk: %s", strerror(errno));
51 
52 	oldbrk = sbrk(0);
53 	ATF_REQUIRE(oldbrk != (void *)-1);
54 
55 	/* Try to allocate a page. */
56 	error = brk((void *)((intptr_t)oldbrk + PAGE_SIZE * 2));
57 	ATF_REQUIRE_MSG(error == 0, "brk: %s", strerror(errno));
58 
59 	/*
60 	 * Attempt to set the break below minbrk.  This should have no effect.
61 	 */
62 	error = brk((void *)((intptr_t)oldbrk - 1));
63 	ATF_REQUIRE_MSG(error == 0, "brk: %s", strerror(errno));
64 	newbrk = sbrk(0);
65 	ATF_REQUIRE_MSG(newbrk != (void *)-1, "sbrk: %s", strerror(errno));
66 	ATF_REQUIRE(newbrk == oldbrk);
67 }
68 
69 ATF_TC(sbrk_basic);
70 ATF_TC_HEAD(sbrk_basic, tc)
71 {
72 	atf_tc_set_md_var(tc, "descr", "Verify basic sbrk() functionality");
73 }
74 ATF_TC_BODY(sbrk_basic, tc)
75 {
76 	void *newbrk, *oldbrk;
77 	int *p;
78 
79 	oldbrk = sbrk(0);
80 	ATF_REQUIRE_MSG(oldbrk != (void *)-1, "sbrk: %s", strerror(errno));
81 	p = sbrk(sizeof(*p));
82 	*p = 0;
83 	ATF_REQUIRE(oldbrk == p);
84 
85 	newbrk = sbrk(-sizeof(*p));
86 	ATF_REQUIRE_MSG(newbrk != (void *)-1, "sbrk: %s", strerror(errno));
87 	ATF_REQUIRE(oldbrk == sbrk(0));
88 
89 	oldbrk = sbrk(PAGE_SIZE * 2 + 1);
90 	ATF_REQUIRE_MSG(oldbrk != (void *)-1, "sbrk: %s", strerror(errno));
91 	memset(oldbrk, 0, PAGE_SIZE * 2 + 1);
92 	newbrk = sbrk(-(PAGE_SIZE * 2 + 1));
93 	ATF_REQUIRE_MSG(newbrk != (void *)-1, "sbrk: %s", strerror(errno));
94 	ATF_REQUIRE(sbrk(0) == oldbrk);
95 }
96 
97 ATF_TC(mlockfuture);
98 ATF_TC_HEAD(mlockfuture, tc)
99 {
100 	atf_tc_set_md_var(tc, "descr",
101 	    "Verify that mlockall(MCL_FUTURE) applies to the data segment");
102 }
103 ATF_TC_BODY(mlockfuture, tc)
104 {
105 	void *oldbrk, *n, *newbrk;
106 	int error;
107 	char v;
108 
109 	error = mlockall(MCL_FUTURE);
110 	ATF_REQUIRE_MSG(error == 0,
111 	    "mlockall: %s", strerror(errno));
112 
113 	/*
114 	 * Advance the break so that at least one page is added to the data
115 	 * segment.  This page should be automatically faulted in to the address
116 	 * space.
117 	 */
118 	oldbrk = sbrk(0);
119 	ATF_REQUIRE(oldbrk != (void *)-1);
120 	newbrk = sbrk(PAGE_SIZE * 2);
121 	ATF_REQUIRE(newbrk != (void *)-1);
122 
123 	n = (void *)(((uintptr_t)oldbrk + PAGE_SIZE) & ~PAGE_SIZE);
124 	v = 0;
125 	error = mincore(n, PAGE_SIZE, &v);
126 	ATF_REQUIRE_MSG(error == 0,
127 	    "mincore: %s", strerror(errno));
128 	ATF_REQUIRE_MSG((v & MINCORE_INCORE) != 0,
129 	    "unexpected page flags %#x", v);
130 
131 	error = brk(oldbrk);
132 	ATF_REQUIRE(error == 0);
133 
134 	error = munlockall();
135 	ATF_REQUIRE_MSG(error == 0,
136 	    "munlockall: %s", strerror(errno));
137 }
138 
139 ATF_TP_ADD_TCS(tp)
140 {
141 	ATF_TP_ADD_TC(tp, brk_basic);
142 	ATF_TP_ADD_TC(tp, sbrk_basic);
143 	ATF_TP_ADD_TC(tp, mlockfuture);
144 
145 	return (atf_no_error());
146 }
147