1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2019 Mark Johnston <[email protected]>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * 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
13 * the 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/mman.h>
32 #include <sys/ptrace.h>
33 #include <sys/wait.h>
34
35 #include <errno.h>
36 #include <signal.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <unistd.h>
40
41 #include <atf-c.h>
42
43 static void
test_wired_copy_on_write(void * addr,size_t len)44 test_wired_copy_on_write(void *addr, size_t len)
45 {
46 int status, val;
47 pid_t pid;
48
49 pid = fork();
50 if (pid == -1)
51 atf_tc_fail("fork() failed: %s", strerror(errno));
52 if (pid == 0) {
53 if (mlock(addr, len) != 0)
54 _exit(1);
55 if (ptrace(PT_TRACE_ME, 0, NULL, 0) != 0)
56 _exit(2);
57 if (raise(SIGSTOP) != 0)
58 _exit(3);
59 if (munlock(addr, len) != 0)
60 _exit(4);
61 _exit(0);
62 }
63
64 ATF_REQUIRE(waitpid(pid, &status, 0) == pid);
65 ATF_REQUIRE_MSG(!WIFEXITED(status),
66 "child exited with status %d", WEXITSTATUS(status));
67 ATF_REQUIRE(WIFSTOPPED(status));
68 ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
69
70 errno = 0;
71 val = ptrace(PT_READ_D, pid, addr, 0);
72 ATF_REQUIRE(errno == 0);
73 ATF_REQUIRE(ptrace(PT_WRITE_D, pid, addr, val) == 0);
74 ATF_REQUIRE(ptrace(PT_CONTINUE, pid, (caddr_t)1, 0) == 0);
75 ATF_REQUIRE(waitpid(pid, &status, 0) == pid);
76 ATF_REQUIRE(WIFEXITED(status));
77 ATF_REQUIRE_MSG(WEXITSTATUS(status) == 0,
78 "child exited with status %d", WSTOPSIG(status));
79 }
80
81 /*
82 * Use ptrace(2) to trigger a copy-on-write fault of anonymous memory.
83 */
84 ATF_TC_WITHOUT_HEAD(mlock__copy_on_write_anon);
ATF_TC_BODY(mlock__copy_on_write_anon,tc)85 ATF_TC_BODY(mlock__copy_on_write_anon, tc)
86 {
87 char *addr;
88 int len;
89
90 len = getpagesize();
91 addr = mmap(NULL, len, PROT_READ, MAP_ANON, -1, 0);
92 ATF_REQUIRE(addr != MAP_FAILED);
93
94 test_wired_copy_on_write(addr, len);
95 }
96
97 /*
98 * Use ptrace(2) to trigger a copy-on-write fault of a read-only text page.
99 */
100 ATF_TC_WITHOUT_HEAD(mlock__copy_on_write_vnode);
ATF_TC_BODY(mlock__copy_on_write_vnode,tc)101 ATF_TC_BODY(mlock__copy_on_write_vnode, tc)
102 {
103 void *addr;
104 int len;
105
106 len = getpagesize();
107 addr = (void *)((uintptr_t)test_wired_copy_on_write & ~(len - 1));
108
109 test_wired_copy_on_write(addr, len);
110 }
111
112 /*
113 * Try truncating and then resizing an mlock()ed mapping.
114 */
115 ATF_TC_WITHOUT_HEAD(mlock__truncate_and_resize);
ATF_TC_BODY(mlock__truncate_and_resize,tc)116 ATF_TC_BODY(mlock__truncate_and_resize, tc)
117 {
118 char filename[16];
119 char *addr;
120 int fd, i, len;
121
122 snprintf(filename, sizeof(filename), "tmp.XXXXXX");
123 fd = mkstemp(filename);
124 ATF_REQUIRE(fd >= 0);
125 ATF_REQUIRE(unlink(filename) == 0);
126
127 len = getpagesize();
128 ATF_REQUIRE(ftruncate(fd, len) == 0);
129
130 addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
131 ATF_REQUIRE(addr != MAP_FAILED);
132 ATF_REQUIRE(mlock(addr, len) == 0);
133 memset(addr, 1, len);
134 ATF_REQUIRE(ftruncate(fd, 0) == 0);
135 ATF_REQUIRE(ftruncate(fd, len) == 0);
136 for (i = 0; i < len; i++)
137 ATF_REQUIRE(addr[i] == 0);
138 ATF_REQUIRE(munlock(addr, len) == 0);
139 }
140
141 /*
142 * Make sure that we can munlock() a truncated mapping.
143 */
144 ATF_TC_WITHOUT_HEAD(mlock__truncate_and_unlock);
ATF_TC_BODY(mlock__truncate_and_unlock,tc)145 ATF_TC_BODY(mlock__truncate_and_unlock, tc)
146 {
147 char filename[16];
148 void *addr;
149 int fd, len;
150
151 snprintf(filename, sizeof(filename), "tmp.XXXXXX");
152 fd = mkstemp(filename);
153 ATF_REQUIRE(fd >= 0);
154 ATF_REQUIRE(unlink(filename) == 0);
155
156 len = getpagesize();
157 ATF_REQUIRE(ftruncate(fd, len) == 0);
158
159 addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
160 ATF_REQUIRE(addr != MAP_FAILED);
161 ATF_REQUIRE(mlock(addr, len) == 0);
162 ATF_REQUIRE(ftruncate(fd, 0) == 0);
163 ATF_REQUIRE(munlock(addr, len) == 0);
164 }
165
ATF_TP_ADD_TCS(tp)166 ATF_TP_ADD_TCS(tp)
167 {
168 ATF_TP_ADD_TC(tp, mlock__copy_on_write_anon);
169 ATF_TP_ADD_TC(tp, mlock__copy_on_write_vnode);
170 ATF_TP_ADD_TC(tp, mlock__truncate_and_resize);
171 ATF_TP_ADD_TC(tp, mlock__truncate_and_unlock);
172
173 return (atf_no_error());
174 }
175