1 /* $NetBSD: t_x86_pte.c,v 1.2 2020/04/26 11:56:38 maxv Exp $ */
2
3 /*
4 * Copyright (c) 2020 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Maxime Villard.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __COPYRIGHT("@(#) Copyright (c) 2020\
34 The NetBSD Foundation, inc. All rights reserved.");
35 __RCSID("$NetBSD: t_x86_pte.c,v 1.2 2020/04/26 11:56:38 maxv Exp $");
36
37 #include <sys/types.h>
38 #include <sys/module.h>
39 #include <sys/sysctl.h>
40 #include <err.h>
41 #include <errno.h>
42 #include <atf-c.h>
43
44 #define mib_name "kern.x86_pte_test.test"
45 #define MODULE_PATH "/usr/tests/modules/x86_pte_tester/x86_pte_tester.kmod"
46 #define MODULE_NAME "x86_pte_tester"
47
48 static struct {
49 size_t n_rwx;
50 size_t n_shstk;
51 bool kernel_map_with_low_ptes;
52 bool pte_is_user_accessible;
53 size_t n_user_space_is_kernel;
54 size_t n_kernel_space_is_user;
55 size_t n_svs_g_bit_set;
56 } x86_pte_results;
57
58 static void
fetch_results(void)59 fetch_results(void)
60 {
61 static bool fetched = false;
62 size_t len = sizeof(x86_pte_results);
63 char module_name[] = MODULE_NAME;
64 modctl_load_t params = {
65 .ml_filename = MODULE_PATH,
66 .ml_flags = MODCTL_NO_PROP,
67 };
68 int rv;
69
70 if (fetched)
71 return;
72
73 if (modctl(MODCTL_LOAD, ¶ms) != 0)
74 atf_tc_skip("loading '%s' module failed.", MODULE_NAME);
75
76 rv = sysctlbyname(mib_name, &x86_pte_results, &len, 0, 0);
77 ATF_REQUIRE_EQ(rv, 0);
78
79 if (modctl(MODCTL_UNLOAD, module_name) != 0)
80 warn("failed to unload module '%s'", MODULE_NAME);
81
82 fetched = true;
83 }
84
85 /* -------------------------------------------------------------------------- */
86
87 ATF_TC(rwx);
ATF_TC_HEAD(rwx,tc)88 ATF_TC_HEAD(rwx, tc)
89 {
90 atf_tc_set_md_var(tc, "descr",
91 "ensure there is no RWX page in the kernel");
92 }
ATF_TC_BODY(rwx,tc)93 ATF_TC_BODY(rwx, tc)
94 {
95 fetch_results();
96 ATF_REQUIRE_EQ(x86_pte_results.n_rwx, 0);
97 }
98
99 /* -------------------------------------------------------------------------- */
100
101 ATF_TC(shstk);
ATF_TC_HEAD(shstk,tc)102 ATF_TC_HEAD(shstk, tc)
103 {
104 atf_tc_set_md_var(tc, "descr",
105 "ensure there is no SHSTK page in the kernel");
106 }
ATF_TC_BODY(shstk,tc)107 ATF_TC_BODY(shstk, tc)
108 {
109 fetch_results();
110 atf_tc_expect_fail("there are %zu SHSTK pages",
111 x86_pte_results.n_shstk);
112 ATF_REQUIRE_EQ(x86_pte_results.n_shstk, 0);
113 }
114
115 /* -------------------------------------------------------------------------- */
116
117 ATF_TC(kernel_map_with_low_ptes);
ATF_TC_HEAD(kernel_map_with_low_ptes,tc)118 ATF_TC_HEAD(kernel_map_with_low_ptes, tc)
119 {
120 atf_tc_set_md_var(tc, "descr",
121 "ensure the kernel map has no user mapping");
122 }
ATF_TC_BODY(kernel_map_with_low_ptes,tc)123 ATF_TC_BODY(kernel_map_with_low_ptes, tc)
124 {
125 fetch_results();
126 ATF_REQUIRE_EQ(x86_pte_results.kernel_map_with_low_ptes, false);
127 }
128
129 /* -------------------------------------------------------------------------- */
130
131 ATF_TC(pte_is_user_accessible);
ATF_TC_HEAD(pte_is_user_accessible,tc)132 ATF_TC_HEAD(pte_is_user_accessible, tc)
133 {
134 atf_tc_set_md_var(tc, "descr",
135 "ensure the PTE space does not have user permissions");
136 }
ATF_TC_BODY(pte_is_user_accessible,tc)137 ATF_TC_BODY(pte_is_user_accessible, tc)
138 {
139 fetch_results();
140 ATF_REQUIRE_EQ(x86_pte_results.pte_is_user_accessible, false);
141 }
142
143 /* -------------------------------------------------------------------------- */
144
145 ATF_TC(user_space_is_kernel);
ATF_TC_HEAD(user_space_is_kernel,tc)146 ATF_TC_HEAD(user_space_is_kernel, tc)
147 {
148 atf_tc_set_md_var(tc, "descr",
149 "ensure no page in the user space has kernel permissions");
150 }
ATF_TC_BODY(user_space_is_kernel,tc)151 ATF_TC_BODY(user_space_is_kernel, tc)
152 {
153 fetch_results();
154 ATF_REQUIRE_EQ(x86_pte_results.n_user_space_is_kernel, 0);
155 }
156
157 /* -------------------------------------------------------------------------- */
158
159 ATF_TC(kernel_space_is_user);
ATF_TC_HEAD(kernel_space_is_user,tc)160 ATF_TC_HEAD(kernel_space_is_user, tc)
161 {
162 atf_tc_set_md_var(tc, "descr",
163 "ensure no page in the kernel space has user permissions");
164 }
ATF_TC_BODY(kernel_space_is_user,tc)165 ATF_TC_BODY(kernel_space_is_user, tc)
166 {
167 fetch_results();
168 ATF_REQUIRE_EQ(x86_pte_results.n_kernel_space_is_user, 0);
169 }
170
171 /* -------------------------------------------------------------------------- */
172
173 ATF_TC(svs_g_bit_set);
ATF_TC_HEAD(svs_g_bit_set,tc)174 ATF_TC_HEAD(svs_g_bit_set, tc)
175 {
176 atf_tc_set_md_var(tc, "descr",
177 "ensure that no page in the SVS map has the G bit set");
178 }
ATF_TC_BODY(svs_g_bit_set,tc)179 ATF_TC_BODY(svs_g_bit_set, tc)
180 {
181 fetch_results();
182 if (x86_pte_results.n_svs_g_bit_set != (size_t)-1) {
183 ATF_REQUIRE_EQ(x86_pte_results.n_svs_g_bit_set, 0);
184 } else {
185 atf_tc_skip("SVS is disabled.");
186 }
187 }
188
189 /* -------------------------------------------------------------------------- */
190
ATF_TP_ADD_TCS(tp)191 ATF_TP_ADD_TCS(tp)
192 {
193 ATF_TP_ADD_TC(tp, rwx);
194 ATF_TP_ADD_TC(tp, shstk);
195 ATF_TP_ADD_TC(tp, kernel_map_with_low_ptes);
196 ATF_TP_ADD_TC(tp, pte_is_user_accessible);
197 ATF_TP_ADD_TC(tp, user_space_is_kernel);
198 ATF_TP_ADD_TC(tp, kernel_space_is_user);
199 ATF_TP_ADD_TC(tp, svs_g_bit_set);
200
201 return atf_no_error();
202 }
203