xref: /xnu-11417.101.15/tests/cpu_counters/cpc_security_tests.c (revision e3723e1f17661b24996789d8afc084c0c3303b26)
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 	T_META_ASROOT(true),
33 	XNU_T_META_SOC_SPECIFIC,
34 	T_META_ENABLED(HAS_CPC_SECURITY),
35 	_T_META_REQUIRES_CPC_SUPPORT);
36 
37 // Several of these tests have two variants to support running on development and release kernels.
38 // 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.
39 
40 // Metadata for running on a development kernel in CPC secure mode.
41 #define _T_META_CPC_SECURE_ON_DEV T_META_SYSCTL_INT("kern.cpc.secure=1"), XNU_T_META_REQUIRES_DEVELOPMENT_KERNEL
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 	size_t kpc_count_allocated = 0;
124 	uint64_t *kpc_configs = NULL;
125 	size_t *kpc_map = NULL;
126 
127 	unsigned int tested = 0;
128 	unsigned int filtered = 0;
129 	unsigned int public_tested = 0;
130 	for (size_t i = 0; i < internal_event_count; i++) {
131 		kpep_event_t event = internal_events[i];
132 		const char *name = NULL;
133 		ret = kpep_event_alias(event, &name);
134 		if (!name) {
135 			ret = kpep_event_name(event, &name);
136 		}
137 		_assert_kpep_ok(ret, "getting event name");
138 		if (strncmp(name, "FIXED", strlen("FIXED")) == 0) {
139 			T_LOG("skipping non-configurable %s event", name);
140 			continue;
141 		}
142 		bool empty_event = strcmp(name, "NO_EVNT") == 0;
143 		if (empty_event) {
144 			continue;
145 		}
146 
147 		kpep_event_t public_event = NULL;
148 		ret = kpep_db_event(public_db, name, &public_event);
149 		bool internal_only = ret == KPEP_ERR_EVENT_NOT_FOUND;
150 		ret = kpep_config_add_event(config, &event, 0, NULL);
151 		_assert_kpep_ok(ret, "adding event %s to configuration", name);
152 
153 		size_t kpc_count = 0;
154 		ret = kpep_config_kpc_count(config, &kpc_count);
155 		_assert_kpep_ok(ret, "getting KPC count");
156 		if (kpc_count == 0) {
157 			T_LOG("skipping event %s with no configuration", name);
158 			ret = kpep_config_remove_event(config, 0);
159 			_assert_kpep_ok(ret, "removing event %s from configuration", name);
160 			continue;
161 		}
162 		if (kpc_count > kpc_count_allocated) {
163 			free(kpc_configs);
164 			kpc_configs = calloc(kpc_count, sizeof(kpc_config_t));
165 			T_QUIET; T_WITH_ERRNO;
166 			T_ASSERT_NOTNULL(kpc_configs, "allocate space for KPC configs");
167 
168 			free(kpc_map);
169 			kpc_map = calloc(kpc_count, sizeof(size_t));
170 			T_QUIET; T_WITH_ERRNO;
171 			T_ASSERT_NOTNULL(kpc_map, "allocate space for KPC map");
172 
173 			kpc_count_allocated = kpc_count;
174 		}
175 
176 		ret = kpep_config_kpc_map(config, kpc_map, kpc_count * sizeof(size_t));
177 		_assert_kpep_ok(ret, "getting KPC map for event %s", name);
178 		ret = kpep_config_kpc(config, (uint8_t *)kpc_configs, kpc_count * sizeof(kpc_config_t));
179 		_assert_kpep_ok(ret, "getting KPC configs for event %s", name);
180 		kpc_config_t kpc_config = kpc_configs[kpc_map[0]];
181 
182 		ret = kpep_config_apply(config);
183 		bool not_permitted = ret == KPEP_ERR_ERRNO && errno == EPERM;
184 		if (not_permitted) {
185 			if (!internal_only) {
186 				T_LOG("failed to configure public event %s (0x%04llx)", name, kpc_config);
187 			}
188 			filtered++;
189 		} else if (internal_only) {
190 			T_FAIL("configured internal-only event %s (0x%04llx) with secure CPC", name, kpc_config);
191 		} else {
192 			public_tested++;
193 		}
194 		ret = kpep_config_remove_event(config, 0);
195 		_assert_kpep_ok(ret, "removing event %s from configuration", name);
196 		tested++;
197 	}
198 
199 	T_LOG("tested %u internal/public events", tested);
200 	T_LOG("correctly permitted to configure %u public events", public_tested);
201 	T_LOG("correctly not permitted to configure %u internal-only events",
202 	    filtered);
203 	kpep_config_free(config);
204 	kpep_db_free(public_db);
205 	kpep_db_free(internal_db);
206 	free(kpc_configs);
207 	free(kpc_map);
208 }
209 
210 T_DECL(secure_cpmu_event_restrictions, "secured CPMU should be restricted to known events",
211     _T_META_CPC_SECURE_ON_DEV, T_META_TAG_VM_NOT_ELIGIBLE)
212 {
213 	check_secure_cpmu();
214 }
215 
216 T_DECL(release_cpmu_event_restrictions, "release CPMU should be restricted to known events",
217     XNU_T_META_REQUIRES_RELEASE_KERNEL, T_META_TAG_VM_NOT_ELIGIBLE)
218 {
219 	check_secure_cpmu();
220 }
221 
222 #define UNCORE_DEV_PATH "/dev/monotonic/uncore"
223 #define UPMU_REF_CYCLES 0x02
224 
225 static void
check_secure_upmu(void)226 check_secure_upmu(void)
227 {
228 	guardid_t guard;
229 	int fd;
230 
231 	guard = 0xa5adcafe;
232 
233 	T_SETUPBEGIN;
234 
235 	fd = guarded_open_np(UNCORE_DEV_PATH, &guard,
236 	    GUARD_CLOSE | GUARD_DUP | GUARD_WRITE, O_CLOEXEC | O_EXCL);
237 	if (fd < 0 && errno == ENOENT) {
238 		T_SKIP("uncore counters are unsupported");
239 	}
240 
241 	union monotonic_ctl_add add_ctl = {
242 		.in.config.event = UPMU_REF_CYCLES,
243 		.in.config.allowed_ctr_mask = 0xffff,
244 	};
245 
246 	T_SETUPEND;
247 
248 	int ret = ioctl(fd, MT_IOC_ADD, &add_ctl);
249 	T_EXPECT_POSIX_FAILURE(ret, EPERM,
250 	    "should not be allowed to count any events on UPMU");
251 }
252 
253 T_DECL(secure_upmu_event_restrictions, "secured UPMU should be restricted to no events",
254     _T_META_CPC_SECURE_ON_DEV, T_META_TAG_VM_NOT_ELIGIBLE)
255 {
256 	check_secure_upmu();
257 }
258 
259 T_DECL(release_upmu_event_restrictions, "release UPMU should be restricted to no events",
260     XNU_T_META_REQUIRES_RELEASE_KERNEL, T_META_TAG_VM_NOT_ELIGIBLE)
261 {
262 	check_secure_upmu();
263 }
264 
265 // Check that events which are exposed publicly are allowed to be configured.
266 
267 static void
check_event_coverage(kpep_db_flags_t flag,const char * kind)268 check_event_coverage(kpep_db_flags_t flag, const char *kind)
269 {
270 	kpep_db_t db = NULL;
271 	int ret = kpep_db_createx(NULL, flag, &db);
272 	_assert_kpep_ok(ret, "creating %s event database", kind);
273 
274 	size_t event_count = 0;
275 	ret = kpep_db_events_count(db, &event_count);
276 	_assert_kpep_ok(ret, "getting %s event count", kind);
277 
278 	kpep_event_t *events = calloc(event_count, sizeof(events[0]));
279 	T_QUIET; T_WITH_ERRNO;
280 	T_ASSERT_NOTNULL(events, "allocate space for events");
281 
282 	ret = kpep_db_events(db, events, event_count * sizeof(events[0]));
283 	_assert_kpep_ok(ret, "getting public events");
284 
285 	kpep_config_t config = NULL;
286 	ret = kpep_config_create(db, &config);
287 	_assert_kpep_ok(ret, "creating event configuration");
288 	ret = kpep_config_force_counters(config);
289 	_assert_kpep_ok(ret, "forcing counters with configuration");
290 
291 	size_t kpc_count_allocated = 0;
292 	uint64_t *kpc_configs = NULL;
293 	size_t *kpc_map = NULL;
294 
295 	unsigned int tested = 0;
296 	for (size_t i = 0; i < event_count; i++) {
297 		kpep_event_t event = events[i];
298 		const char *name = NULL;
299 		ret = kpep_event_name(event, &name);
300 		_assert_kpep_ok(ret, "getting event name");
301 		if (strncmp(name, "FIXED", strlen("FIXED")) == 0) {
302 			T_LOG("skipping non-configurable %s event", name);
303 			continue;
304 		}
305 
306 		ret = kpep_config_add_event(config, &event, 0, NULL);
307 		_assert_kpep_ok(ret, "adding event %s to configuration", name);
308 
309 		size_t kpc_count = 0;
310 		ret = kpep_config_kpc_count(config, &kpc_count);
311 		_assert_kpep_ok(ret, "getting KPC count");
312 		if (kpc_count > kpc_count_allocated) {
313 			free(kpc_configs);
314 			kpc_configs = calloc(kpc_count, sizeof(kpc_config_t));
315 			T_QUIET; T_WITH_ERRNO;
316 			T_ASSERT_NOTNULL(kpc_configs, "allocate space for KPC configs");
317 			kpc_count_allocated = kpc_count;
318 
319 			free(kpc_map);
320 			kpc_map = calloc(kpc_count, sizeof(size_t));
321 			T_QUIET; T_WITH_ERRNO;
322 			T_ASSERT_NOTNULL(kpc_map, "allocate space for KPC map");
323 		}
324 
325 		ret = kpep_config_kpc_map(config, kpc_map, kpc_count * sizeof(size_t));
326 		_assert_kpep_ok(ret, "getting KPC map for event %s", name);
327 		ret = kpep_config_kpc(config, (uint8_t *)kpc_configs, kpc_count * sizeof(kpc_config_t));
328 		_assert_kpep_ok(ret, "getting KPC configs for event %s", name);
329 		kpc_config_t kpc_config = kpc_configs[kpc_map[0]];
330 
331 		ret = kpep_config_apply(config);
332 		if (ret == KPEP_ERR_ERRNO && errno == EPERM) {
333 			T_FAIL("failed to configure %s event %s (0x%04llx) with secure CPC", kind, name, kpc_config);
334 		} else {
335 			_assert_kpep_ok(ret, "applying configuration with event %s (0x%04llx)", name, kpc_config);
336 		}
337 		ret = kpep_config_remove_event(config, 0);
338 		_assert_kpep_ok(ret, "removing event %s from configuration", name);
339 		tested++;
340 	}
341 
342 	T_LOG("attempted to configure %u %s events", tested, kind);
343 	kpep_config_free(config);
344 	kpep_db_free(db);
345 	free(kpc_configs);
346 	free(kpc_map);
347 }
348 
349 T_DECL(secure_public_event_coverage, "all public events in kpep should be allowed",
350     _T_META_CPC_SECURE_ON_DEV, T_META_TAG_VM_NOT_ELIGIBLE)
351 {
352 	check_event_coverage(KPEP_DB_FLAG_PUBLIC_ONLY, "public");
353 }
354 
355 T_DECL(release_public_event_coverage, "all public events in kpep should be allowed",
356     XNU_T_META_REQUIRES_RELEASE_KERNEL, T_META_TAG_VM_NOT_ELIGIBLE)
357 {
358 	check_event_coverage(KPEP_DB_FLAG_PUBLIC_ONLY, "public");
359 }
360 
361 // Check for internal development behaviors.
362 T_DECL(insecure_cpmu_unrestricted, "insecure CPMU should be unrestricted",
363     XNU_T_META_REQUIRES_DEVELOPMENT_KERNEL, T_META_SYSCTL_INT("kern.cpc.secure=0"), T_META_TAG_VM_NOT_ELIGIBLE)
364 {
365 	check_event_coverage(KPEP_DB_FLAG_INTERNAL_ONLY, "internal");
366 }
367 
368 T_DECL(secure_kpc_counting_system, "kpc should not allow counting the kernel when secure",
369     _T_META_CPC_SECURE_ON_DEV)
370 {
371 	kpep_db_t db = NULL;
372 	int ret = kpep_db_createx(NULL, KPEP_DB_FLAG_PUBLIC_ONLY, &db);
373 	_assert_kpep_ok(ret, "creating public event database");
374 
375 	size_t event_count = 0;
376 	ret = kpep_db_events_count(db, &event_count);
377 	_assert_kpep_ok(ret, "getting public event count");
378 
379 	kpep_event_t *events = calloc(event_count, sizeof(events[0]));
380 	T_QUIET; T_WITH_ERRNO;
381 	T_ASSERT_NOTNULL(events, "allocate space for events");
382 
383 	ret = kpep_db_events(db, events, event_count * sizeof(events[0]));
384 	_assert_kpep_ok(ret, "getting public events");
385 
386 	kpep_config_t config = NULL;
387 	ret = kpep_config_create(db, &config);
388 	_assert_kpep_ok(ret, "creating event configuration");
389 	ret = kpep_config_force_counters(config);
390 	_assert_kpep_ok(ret, "forcing counters with configuration");
391 
392 
393 	kpep_event_t event = NULL;
394 	const char *name = NULL;
395 	for (size_t i = 0; i < event_count; i++) {
396 		event = events[i];
397 		ret = kpep_event_name(event, &name);
398 		_assert_kpep_ok(ret, "getting event name");
399 		if (strncmp(name, "FIXED", strlen("FIXED")) != 0) {
400 			break;
401 		}
402 		T_LOG("skipping non-configurable %s event", name);
403 	}
404 
405 	ret = kpep_config_add_event(config, &event, KPEP_EVENT_FLAG_KERNEL, NULL);
406 	_assert_kpep_ok(ret, "adding event %s to configuration", name);
407 
408 	ret = kpep_config_apply(config);
409 	_assert_kpep_ok(ret, "applying configuration with event %s", name);
410 
411 	uint32_t config_count = kpc_get_config_count(KPC_CLASS_CONFIGURABLE_MASK);
412 	uint64_t *configs = calloc(config_count, sizeof(configs[0]));
413 	T_QUIET;
414 	T_ASSERT_NOTNULL(configs, "allocated %u * %zu", config_count, sizeof(configs[0]));
415 	ret = kpc_get_config(KPC_CLASS_CONFIGURABLE_MASK, configs);
416 	for (uint32_t i = 0; i < config_count; i++) {
417 		if ((configs[i] & 0x40000)) {
418 			T_FAIL("found configurable counter %u with configuration 0x%llx", i, configs[i]);
419 		}
420 	}
421 	T_LOG("checked %d events for EL2 counting", config_count);
422 
423 	kpep_config_free(config);
424 	kpep_db_free(db);
425 }
426