1 // Copyright 2023 (c) Apple Inc. All rights reserved.
2
3 #include <darwintest.h>
4 #include <darwintest_utils.h>
5 #include <dirent.h>
6 #include <kperf/kpc.h>
7 #include <kperfdata/kpep.h>
8 #include <stdarg.h>
9 #include <stdbool.h>
10 #include <string.h>
11 #include <sys/guarded.h>
12 #include <sys/ioctl.h>
13 #include <sys/monotonic.h>
14
15 #include "test_utils.h"
16
17 #if __arm64__
18 #define HAS_CPC_SECURITY true
19 #else // __arm64__
20 #define HAS_CPC_SECURITY false
21 #endif // !__arm64__
22
23 #define _T_META_REQUIRES_CPC_SUPPORT \
24 T_META_REQUIRES_SYSCTL_EQ("kern.monotonic.supported", "1")
25
26 T_GLOBAL_META(
27 T_META_NAMESPACE("xnu.cpc"),
28 T_META_RADAR_COMPONENT_NAME("xnu"),
29 T_META_RADAR_COMPONENT_VERSION("cpu counters"),
30 T_META_OWNER("mwidmann"),
31 T_META_CHECK_LEAKS(false),
32 XNU_T_META_SOC_SPECIFIC,
33 T_META_ENABLED(HAS_CPC_SECURITY),
34 _T_META_REQUIRES_CPC_SUPPORT);
35
36 // Several of these tests have two variants to support running on development and release kernels.
37 // Tests prefixed with `secure_` put the development kernel into a secure CPC mode while tests prefixed with `release_` can run on the RELEASE build variant.
38
39 // Metadata for running on a development kernel in CPC secure mode.
40 #define _T_META_CPC_SECURE_ON_DEV \
41 XNU_T_META_REQUIRES_DEVELOPMENT_KERNEL, T_META_SYSCTL_INT("kern.cpc.secure=1")
42
43 static void
_assert_kpep_ok(int kpep_err,const char * fmt,...)44 _assert_kpep_ok(int kpep_err, const char *fmt, ...)
45 {
46 char msg[1024] = "";
47 va_list args;
48 va_start(args, fmt);
49 vsnprintf(msg, sizeof(msg), fmt, args);
50 va_end(args);
51 T_QUIET;
52 T_ASSERT_EQ(kpep_err, KPEP_ERR_NONE, "%s: %s", msg, kpep_strerror(kpep_err));
53 }
54
55 static void
_skip_for_db(const char * kind,int kpep_err)56 _skip_for_db(const char *kind, int kpep_err)
57 {
58 const char * const public_kpep_path = "/usr/share/kpep";
59 const char * const internal_kpep_path = "/usr/local/share/kpep";
60 const char * const paths[2] = { public_kpep_path, internal_kpep_path, };
61 for (int i = 0; i < 2; i++) {
62 const char * const path = paths[i];
63 T_LOG("contents of %s:", path);
64 DIR *dir = opendir(path);
65 if (dir) {
66 struct dirent *entry = NULL;
67 while ((entry = readdir(dir)) != NULL) {
68 T_LOG(" %s", entry->d_name);
69 }
70 (void)closedir(dir);
71 } else {
72 T_LOG("failed to open directory: %s", strerror(errno));
73 }
74 }
75 int cpu_family = 0;
76 size_t family_size = sizeof(cpu_family);
77 int ret = sysctlbyname("hw.cpufamily", &cpu_family, &family_size, NULL, 0);
78 if (ret != 0) {
79 T_LOG("HW CPU family: 0x%8x", cpu_family);
80 } else {
81 T_LOG("failed to get hw.cpufamily: %s", strerror(errno));
82 }
83 T_SKIP("cannot open %s event database: %s", kind, kpep_strerror(kpep_err));
84 }
85
86 // Check that a secure kernel disallows restricted events.
87
88 static void
check_secure_cpmu(void)89 check_secure_cpmu(void)
90 {
91 kpep_db_t public_db = NULL;
92 int ret = kpep_db_createx(NULL, KPEP_DB_FLAG_PUBLIC_ONLY, &public_db);
93 if (ret != KPEP_ERR_NONE) {
94 _skip_for_db("public", ret);
95 }
96 kpep_db_t internal_db = NULL;
97 ret = kpep_db_createx(NULL, KPEP_DB_FLAG_INTERNAL_ONLY, &internal_db);
98 if (ret != KPEP_ERR_NONE) {
99 _skip_for_db("internal", ret);
100 }
101 const char *na = NULL;
102 kpep_db_name(public_db, &na);
103
104 size_t internal_event_count = 0;
105 ret = kpep_db_events_count(internal_db, &internal_event_count);
106 _assert_kpep_ok(ret, "getting internal event count");
107
108 kpep_event_t *internal_events = calloc(internal_event_count,
109 sizeof(internal_events[0]));
110 T_QUIET; T_WITH_ERRNO;
111 T_ASSERT_NOTNULL(internal_events, "allocate space for internal events");
112
113 ret = kpep_db_events(internal_db, internal_events,
114 internal_event_count * sizeof(internal_events[0]));
115 _assert_kpep_ok(ret, "getting internal events");
116
117 kpep_config_t config = NULL;
118 ret = kpep_config_create(internal_db, &config);
119 _assert_kpep_ok(ret, "creating event configuration");
120 ret = kpep_config_force_counters(config);
121 _assert_kpep_ok(ret, "forcing counters with configuration");
122
123 unsigned int tested = 0;
124 unsigned int filtered = 0;
125 unsigned int public_tested = 0;
126 for (size_t i = 0; i < internal_event_count; i++) {
127 kpep_event_t event = internal_events[i];
128 const char *name = NULL;
129 ret = kpep_event_alias(event, &name);
130 if (!name) {
131 ret = kpep_event_name(event, &name);
132 }
133 _assert_kpep_ok(ret, "getting event name");
134 if (strncmp(name, "FIXED", strlen("FIXED")) == 0) {
135 T_LOG("skipping non-configurable %s event", name);
136 continue;
137 }
138 bool empty_event = strcmp(name, "NO_EVNT") == 0;
139 if (empty_event) {
140 continue;
141 }
142
143 kpep_event_t public_event = NULL;
144 ret = kpep_db_event(public_db, name, &public_event);
145 bool internal_only = ret == KPEP_ERR_EVENT_NOT_FOUND;
146 ret = kpep_config_add_event(config, &event, 0, NULL);
147 _assert_kpep_ok(ret, "adding event %s to configuration", name);
148
149 ret = kpep_config_apply(config);
150 bool not_permitted = ret == KPEP_ERR_ERRNO && errno == EPERM;
151 if (not_permitted) {
152 if (!internal_only) {
153 T_LOG("failed to configure public event %s", name);
154 }
155 filtered++;
156 } else if (internal_only) {
157 T_FAIL("configured internal-only event %s with secure CPC", name);
158 } else {
159 public_tested++;
160 }
161 ret = kpep_config_remove_event(config, 0);
162 _assert_kpep_ok(ret, "removing event %s from configuration", name);
163 tested++;
164 }
165
166 T_LOG("tested %u internal/public events", tested);
167 T_LOG("correctly permitted to configure %u public events", public_tested);
168 T_LOG("correctly not permitted to configure %u internal-only events",
169 filtered);
170 kpep_config_free(config);
171 kpep_db_free(public_db);
172 kpep_db_free(internal_db);
173 }
174
175 T_DECL(secure_cpmu_event_restrictions, "secured CPMU should be restricted to known events",
176 _T_META_CPC_SECURE_ON_DEV)
177 {
178 check_secure_cpmu();
179 }
180
181 T_DECL(release_cpmu_event_restrictions, "release CPMU should be restricted to known events",
182 XNU_T_META_REQUIRES_RELEASE_KERNEL)
183 {
184 check_secure_cpmu();
185 }
186
187 #define UNCORE_DEV_PATH "/dev/monotonic/uncore"
188 #define UPMU_REF_CYCLES 0x02
189
190 static void
check_secure_upmu(void)191 check_secure_upmu(void)
192 {
193 guardid_t guard;
194 int fd;
195
196 guard = 0xa5adcafe;
197
198 T_SETUPBEGIN;
199
200 fd = guarded_open_np(UNCORE_DEV_PATH, &guard,
201 GUARD_CLOSE | GUARD_DUP | GUARD_WRITE, O_CLOEXEC | O_EXCL);
202 if (fd < 0 && errno == ENOENT) {
203 T_SKIP("uncore counters are unsupported");
204 }
205
206 union monotonic_ctl_add add_ctl = {
207 .in.config.event = UPMU_REF_CYCLES,
208 .in.config.allowed_ctr_mask = 0xffff,
209 };
210
211 T_SETUPEND;
212
213 int ret = ioctl(fd, MT_IOC_ADD, &add_ctl);
214 T_EXPECT_POSIX_FAILURE(ret, EPERM,
215 "should not be allowed to count any events on UPMU");
216 }
217
218 T_DECL(secure_upmu_event_restrictions, "secured UPMU should be restricted to no events",
219 _T_META_CPC_SECURE_ON_DEV)
220 {
221 check_secure_upmu();
222 }
223
224 T_DECL(release_upmu_event_restrictions, "release UPMU should be restricted to no events",
225 XNU_T_META_REQUIRES_RELEASE_KERNEL)
226 {
227 check_secure_upmu();
228 }
229
230 // Check that events which are exposed publicly are allowed to be configured.
231
232 static void
check_event_coverage(kpep_db_flags_t flag,const char * kind)233 check_event_coverage(kpep_db_flags_t flag, const char *kind)
234 {
235 kpep_db_t db = NULL;
236 int ret = kpep_db_createx(NULL, flag, &db);
237 _assert_kpep_ok(ret, "creating %s event database", kind);
238
239 size_t event_count = 0;
240 ret = kpep_db_events_count(db, &event_count);
241 _assert_kpep_ok(ret, "getting %s event count", kind);
242
243 kpep_event_t *events = calloc(event_count, sizeof(events[0]));
244 T_QUIET; T_WITH_ERRNO;
245 T_ASSERT_NOTNULL(events, "allocate space for events");
246
247 ret = kpep_db_events(db, events, event_count * sizeof(events[0]));
248 _assert_kpep_ok(ret, "getting public events");
249
250 kpep_config_t config = NULL;
251 ret = kpep_config_create(db, &config);
252 _assert_kpep_ok(ret, "creating event configuration");
253 ret = kpep_config_force_counters(config);
254 _assert_kpep_ok(ret, "forcing counters with configuration");
255
256 unsigned int tested = 0;
257 for (size_t i = 0; i < event_count; i++) {
258 kpep_event_t event = events[i];
259 const char *name = NULL;
260 ret = kpep_event_name(event, &name);
261 _assert_kpep_ok(ret, "getting event name");
262 if (strncmp(name, "FIXED", strlen("FIXED")) == 0) {
263 T_LOG("skipping non-configurable %s event", name);
264 continue;
265 }
266
267 ret = kpep_config_add_event(config, &event, 0, NULL);
268 _assert_kpep_ok(ret, "adding event %s to configuration", name);
269
270 ret = kpep_config_apply(config);
271 if (ret == KPEP_ERR_ERRNO && errno == EPERM) {
272 T_FAIL("failed to configure %s event %s with secure CPC", kind, name);
273 } else {
274 _assert_kpep_ok(ret, "applying configuration with event %s", name);
275 }
276 ret = kpep_config_remove_event(config, 0);
277 _assert_kpep_ok(ret, "removing event %s from configuration", name);
278 tested++;
279 }
280
281 T_LOG("successfully configured %u %s events", tested, kind);
282 kpep_config_free(config);
283 kpep_db_free(db);
284 }
285
286 T_DECL(secure_public_event_coverage, "all public events in kpep should be allowed",
287 _T_META_CPC_SECURE_ON_DEV)
288 {
289 check_event_coverage(KPEP_DB_FLAG_PUBLIC_ONLY, "public");
290 }
291
292 T_DECL(release_public_event_coverage, "all public events in kpep should be allowed",
293 XNU_T_META_REQUIRES_RELEASE_KERNEL)
294 {
295 check_event_coverage(KPEP_DB_FLAG_PUBLIC_ONLY, "public");
296 }
297
298 // Check for internal development behaviors.
299
300 T_DECL(insecure_cpmu_unrestricted, "insecure CPMU should be unrestricted",
301 XNU_T_META_REQUIRES_DEVELOPMENT_KERNEL, T_META_SYSCTL_INT("kern.cpc.secure=0"))
302 {
303 check_event_coverage(KPEP_DB_FLAG_INTERNAL_ONLY, "internal");
304 }
305