xref: /xnu-12377.61.12/tests/arm_mte.c (revision 4d495c6e23c53686cf65f45067f79024cf5dcee8)
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28 
29 #include <arm_acle.h>
30 #include <darwintest.h>
31 #include <fcntl.h>
32 #include <mach/mach.h>
33 #include <mach/mach_vm.h>
34 #include <mach/vm_map.h>
35 #include <mach-o/dyld.h>
36 #include <spawn_private.h>
37 #include <sys/aio.h>
38 #include <sys/spawn_internal.h>
39 #include <stdlib.h>
40 #include <sys/mman.h>
41 #include <sys/sysctl.h>
42 #include <sys/wait.h>
43 #include <signal.h>
44 
45 #include "arm_mte_utilities.h"
46 #include "test_utils.h"
47 
48 #if (TARGET_OS_OSX || TARGET_OS_IOS) && defined(__arm64__)
49 // TODO(PT): It'd be nice to have this as an allow list rather than the inverse,
50 // but I wasn't able to restrict based on TARGET_OS_[IPHONE|IOS] as this is sometimes set even for XR_OS.
51 // For now, to keep things moving, just restrict this from being set on platforms where
52 // we know it's not the case.
53 #if !(TARGET_OS_XR || TARGET_OS_TV || TARGET_OS_WATCH || TARGET_OS_BRIDGE)
54 	#define TARGET_SUPPORTS_MTE_EMULATION 1
55 #endif
56 #endif
57 
58 T_GLOBAL_META(
59 	T_META_NAMESPACE("xnu.arm"),
60 	T_META_RADAR_COMPONENT_NAME("xnu"),
61 	T_META_RADAR_COMPONENT_VERSION("arm"),
62 	T_META_OWNER("ghackmann"),
63 	T_META_RUN_CONCURRENTLY(true),
64 	T_META_IGNORECRASHES(".*arm_mte.*"),
65 	T_META_CHECK_LEAKS(false));
66 
67 static uint64_t
task_footprint(void)68 task_footprint(void)
69 {
70 	task_vm_info_data_t ti;
71 	kern_return_t kr;
72 	mach_msg_type_number_t count;
73 
74 	count = TASK_VM_INFO_COUNT;
75 	kr = task_info(mach_task_self(),
76 	    TASK_VM_INFO,
77 	    (task_info_t) &ti,
78 	    &count);
79 	T_QUIET;
80 	T_ASSERT_MACH_SUCCESS(kr, "task_info()");
81 #if defined(__arm64__)
82 	T_QUIET;
83 	T_ASSERT_EQ(count, TASK_VM_INFO_COUNT, "task_info() count = %d (expected %d)",
84 	    count, TASK_VM_INFO_COUNT);
85 #endif /* defined(__arm64__) */
86 	return ti.phys_footprint;
87 }
88 
89 static void
do_mte_tag_check(void)90 do_mte_tag_check(void)
91 {
92 	static const size_t ALLOC_SIZE = MTE_GRANULE_SIZE * 2;
93 
94 	vm_address_t address = 0;
95 	kern_return_t kr = vm_allocate(mach_task_self(), &address, ALLOC_SIZE, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
96 	T_ASSERT_MACH_SUCCESS(kr, "allocate tagged memory");
97 	char *untagged_ptr = (char *)address;
98 
99 	char *orig_tagged_ptr = __arm_mte_get_tag(untagged_ptr);
100 	unsigned int orig_tag = extract_mte_tag(orig_tagged_ptr);
101 	T_ASSERT_EQ_UINT(orig_tag, 0U, "originally assigned tag is zero");
102 
103 	uint64_t mask = __arm_mte_exclude_tag(orig_tagged_ptr, 0);
104 	T_EXPECT_EQ_LLONG(mask, (1LL << 0), "zero tag is excluded");
105 
106 	char *random_tagged_ptr = NULL;
107 	/*
108 	 * Generate the random tag.  We've excluded the original tag, so it should never
109 	 * reappear no matter how many times we regenerate a new tag.
110 	 */
111 	for (unsigned int i = 0; i < NUM_MTE_TAGS * 4; i++) {
112 		random_tagged_ptr = __arm_mte_create_random_tag(untagged_ptr, mask);
113 		T_QUIET; T_EXPECT_NE_PTR(orig_tagged_ptr, random_tagged_ptr,
114 		    "random tag was not taken from excluded tag set");
115 
116 		ptrdiff_t diff = __arm_mte_ptrdiff(untagged_ptr, random_tagged_ptr);
117 		T_QUIET; T_EXPECT_EQ_ULONG(diff, (ptrdiff_t)0, "untagged %p and tagged %p have identical address bits",
118 		    untagged_ptr, random_tagged_ptr);
119 	}
120 
121 	/* Time to make things real, commit the tag to memory */
122 	__arm_mte_set_tag(random_tagged_ptr);
123 
124 	/* Ensure that we can read back the tag */
125 	char *read_back = __arm_mte_get_tag(untagged_ptr);
126 	T_EXPECT_EQ_PTR(read_back, random_tagged_ptr, "tag was committed to memory correctly");
127 
128 	/* Verify that accessing memory actually works */
129 	random_tagged_ptr[0] = 't';
130 	random_tagged_ptr[1] = 'e';
131 	random_tagged_ptr[2] = 's';
132 	random_tagged_ptr[3] = 't';
133 	T_EXPECT_EQ_STR(random_tagged_ptr, "test", "read/write from tagged memory");
134 
135 	/*
136 	 * Confirm that the next MTE granule still has the default tag, and then
137 	 * simulate an out-of-bounds access into that granule.
138 	 */
139 	void *next_granule_ptr = orig_tagged_ptr + MTE_GRANULE_SIZE;
140 	unsigned int next_granule_tag = extract_mte_tag(next_granule_ptr);
141 	T_QUIET; T_ASSERT_EQ_UINT(next_granule_tag, 0U,
142 	    "next MTE granule still has its originally assigned tag");
143 
144 	T_LOG("attempting out-of-bounds access to tagged memory");
145 	expect_sigkill(^{
146 		random_tagged_ptr[MTE_GRANULE_SIZE] = '!';
147 	}, "out-of-bounds access to tagged memory raises uncatchable exception");
148 
149 	/*
150 	 * Simulate a use-after-free by accessing orig_tagged_ptr, which has an
151 	 * out-of-date tag.
152 	 */
153 	T_LOG("attempting use-after-free access to tagged memory");
154 	expect_sigkill(^{
155 		orig_tagged_ptr[0] = 'T';
156 	}, "use-after-free access to tagged memory raises uncatchable exception");
157 
158 	__arm_mte_set_tag(orig_tagged_ptr);
159 	__arm_mte_set_tag(orig_tagged_ptr + MTE_GRANULE_SIZE);
160 	vm_deallocate(mach_task_self(), address, ALLOC_SIZE);
161 }
162 
163 T_DECL(mte_tag_check,
164     "Test MTE2 tag check fault handling",
165     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
166     XNU_T_META_SOC_SPECIFIC)
167 {
168 #if !__arm64__
169 	T_SKIP("Running on non-arm64 target, skipping...");
170 #else /* !__arm64__ */
171 	do_mte_tag_check();
172 #endif
173 }
174 
175 T_DECL(mte_tag_check_child,
176     "Test MTE2 tag check fault in a child process",
177     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
178     XNU_T_META_SOC_SPECIFIC)
179 {
180 #if !__arm64__
181 	T_SKIP("Running on non-arm64 target, skipping...");
182 #else /* !__arm64__ */
183 	pid_t pid = fork();
184 	if (pid == 0) {
185 		/*
186 		 * Make sure the child process also has tag checks enabled.
187 		 */
188 		do_mte_tag_check();
189 	} else {
190 		T_ASSERT_TRUE(pid != -1, "Checking fork success in parent");
191 
192 		int status = 0;
193 		T_ASSERT_POSIX_SUCCESS(waitpid(pid, &status, 0), "waitpid");
194 	}
195 #endif
196 }
197 
198 T_DECL(mte_canonical_tag_check,
199     "Test MTE4 Canonical Tag Check fault handling",
200     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
201     XNU_T_META_SOC_SPECIFIC)
202 {
203 #if !__arm64__
204 	T_SKIP("Running on non-arm64 target, skipping...");
205 #else /* !__arm64__ */
206 	vm_address_t address = 0;
207 	kern_return_t kr = vm_allocate(mach_task_self(), &address, MTE_GRANULE_SIZE, VM_FLAGS_ANYWHERE);
208 	T_ASSERT_MACH_SUCCESS(kr, "allocate a canonically-tagged page");
209 	char *ptr = (char *)address;
210 
211 	T_LOG("attempting to set tag on canonically-tagged memory");
212 	char *tagged_ptr = __arm_mte_increment_tag(ptr, 1);
213 	expect_signal(SIGBUS, ^{
214 		__arm_mte_set_tag(tagged_ptr);
215 	}, "setting tag on canonically-tagged memory raises a canonical memory permission fault");
216 
217 	T_LOG("attempting to access canonically-tagged memory with a tagged address");
218 	expect_sigkill(^{
219 		tagged_ptr[0] = '!';
220 	}, "accessing canonically-tagged memory with a tagged address raises a canonical tag check fault");
221 
222 	vm_deallocate(mach_task_self(), address, MTE_GRANULE_SIZE);
223 #endif
224 }
225 
226 static void
run_mte_copyio_tests(bool tag_check_faults_enabled)227 run_mte_copyio_tests(bool tag_check_faults_enabled)
228 {
229 	static_assert(MAXTHREADNAMESIZE >= MTE_GRANULE_SIZE * 2, "kern.threadname parameter can span multiple MTE granules");
230 
231 	const size_t buf_size = MAXTHREADNAMESIZE;
232 	const size_t threadname_len = MTE_GRANULE_SIZE * 2;
233 	vm_address_t address = 0;
234 	kern_return_t kr = vm_allocate(mach_task_self(), &address, buf_size, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
235 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "allocate tagged memory");
236 
237 	char *untagged_ptr = (char *)address;
238 	/* n.b.: kern.threadname uses unterminated strings */
239 	memset(untagged_ptr, 'A', threadname_len);
240 
241 	char *tagged_ptr = __arm_mte_create_random_tag(untagged_ptr, 0);
242 	__arm_mte_set_tag(tagged_ptr);
243 	char *next_granule_ptr = tagged_ptr + MTE_GRANULE_SIZE;
244 	__arm_mte_set_tag(next_granule_ptr);
245 
246 	int err = sysctlbyname("kern.threadname", NULL, NULL, tagged_ptr, threadname_len);
247 	T_ASSERT_POSIX_SUCCESS(err, "copyin using tagged pointer succeeds");
248 
249 	/* Simulate use-after-free by passing in obsolete tag */
250 	if (tag_check_faults_enabled) {
251 		expect_sigkill(^{
252 			sysctlbyname("kern.threadname", NULL, NULL, untagged_ptr, threadname_len);
253 		}, "copyin using incorrectly-tagged pointer");
254 	} else {
255 		err = sysctlbyname("kern.threadname", NULL, NULL, untagged_ptr, threadname_len);
256 		T_ASSERT_POSIX_SUCCESS(err, "bypass: copyin using incorrectly-tagged pointer succeeds");
257 	}
258 
259 	/* Simulate out-of-bounds access by giving the second MTE granule a different tag */
260 	char *different_tag_next_granule_ptr = __arm_mte_increment_tag(next_granule_ptr, 1);
261 	T_QUIET; T_ASSERT_NE(different_tag_next_granule_ptr, next_granule_ptr, "__arm_mte_increment_tag()");
262 	__arm_mte_set_tag(different_tag_next_granule_ptr);
263 	if (tag_check_faults_enabled) {
264 		expect_sigkill(^{
265 			sysctlbyname("kern.threadname", NULL, NULL, tagged_ptr, threadname_len);
266 		}, "copyin using inconsistently-tagged buffer");
267 	} else {
268 		err = sysctlbyname("kern.threadname", NULL, NULL, tagged_ptr, threadname_len);
269 		T_ASSERT_POSIX_SUCCESS(err, "bypass: copyin using inconsistently-tagged buffer succeeds");
270 	}
271 	__arm_mte_set_tag(next_granule_ptr);
272 
273 	size_t oldlen = buf_size;
274 	err = sysctlbyname("kern.threadname", tagged_ptr, &oldlen, NULL, 0);
275 	T_EXPECT_POSIX_SUCCESS(err, "copyout using tagged pointer succeeds");
276 
277 #pragma clang diagnostic push
278 #pragma clang diagnostic ignored "-Wshadow"
279 
280 	if (tag_check_faults_enabled) {
281 		expect_sigkill(^{
282 			/* We need to repopulate kern.threadname since it isn't inherited across fork() */
283 			int err = sysctlbyname("kern.threadname", NULL, NULL, tagged_ptr, threadname_len);
284 			T_QUIET; T_ASSERT_POSIX_SUCCESS(err, "sysctlbyname(kern.threadname)");
285 
286 			size_t oldlen = buf_size;
287 			sysctlbyname("kern.threadname", untagged_ptr, &oldlen, NULL, 0);
288 		}, "copyout using incorrectly-tagged pointer");
289 	} else {
290 		size_t oldlen = buf_size;
291 		int err = sysctlbyname("kern.threadname", untagged_ptr, &oldlen, NULL, 0);
292 		T_EXPECT_POSIX_SUCCESS(err, "bypass: copyout using incorrectly-tagged pointer succeeds");
293 	}
294 
295 	__arm_mte_set_tag(different_tag_next_granule_ptr);
296 	if (tag_check_faults_enabled) {
297 		expect_sigkill(^{
298 			int err = sysctlbyname("kern.threadname", NULL, NULL, tagged_ptr, threadname_len);
299 			T_QUIET; T_ASSERT_POSIX_SUCCESS(err, "sysctlbyname(kern.threadname)");
300 
301 			size_t oldlen = buf_size;
302 			sysctlbyname("kern.threadname", tagged_ptr, &oldlen, NULL, 0);
303 		}, "copyout using inconsistently-tagged buffer");
304 	} else {
305 		size_t oldlen = buf_size;
306 		int err = sysctlbyname("kern.threadname", tagged_ptr, &oldlen, NULL, 0);
307 		T_EXPECT_POSIX_SUCCESS(err, "bypass: copyout using inconsistently-tagged buffer succeeds");
308 	}
309 	__arm_mte_set_tag(next_granule_ptr);
310 
311 #pragma clang diagnostic pop
312 
313 	vm_deallocate(mach_task_self(), address, buf_size);
314 }
315 
316 T_DECL(mte_copyio,
317     "Test MTE tag handling during copyin/copyout operations",
318     T_META_ENABLED(TARGET_CPU_ARM64),
319     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
320     XNU_T_META_SOC_SPECIFIC)
321 {
322 	run_mte_copyio_tests(true);
323 }
324 
325 T_DECL(mte_malloc_footprint_test,
326     "Test footprint across malloc() and free()",
327     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
328     XNU_T_META_SOC_SPECIFIC,
329     T_META_ENABLED(false) /* rdar://131390446 */)
330 {
331 #if !__arm64__
332 	T_SKIP("Running on non-arm64 target, skipping...");
333 #else /* !__arm64__ */
334 	uint64_t count = 1024;
335 	uint64_t margin = 4;
336 	char* address[count];
337 	uint64_t size = PAGE_SIZE;
338 
339 	for (unsigned int i = 0; i < count; i++) {
340 		address[i] = (char *) malloc(size);
341 
342 		char *cp;
343 		for (cp = (char *) (address[i]); cp < (char *) (address[i] + size); cp += PAGE_SIZE) {
344 			*cp = 'x';
345 		}
346 	}
347 
348 	uint64_t fp1 = task_footprint();
349 	T_LOG("Footprint after malloc(): %llu bytes", fp1);
350 
351 	for (unsigned int i = 0; i < count; i++) {
352 		free(address[i]);
353 	}
354 	uint64_t fp2 = task_footprint();
355 	T_LOG("Footprint after free(): %llu bytes", fp2);
356 
357 	T_EXPECT_TRUE(((fp2 + PAGE_SIZE * (count - margin)) <= fp1), "Footprint after free() is higher than expected.");
358 #endif
359 }
360 
361 T_DECL(mte_tagged_memory_direct_io,
362     "Test direct I/O on tagged memory",
363     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
364     XNU_T_META_SOC_SPECIFIC)
365 {
366 #if !__arm64__
367 	T_SKIP("Running on non-arm64 target, skipping...");
368 #else /* !__arm64__ */
369 
370 	uint64_t size = PAGE_SIZE;
371 	char* address = (char*) malloc(size);
372 
373 	char *cp;
374 	for (cp = (char *) (address); cp < (char *) (address + size); cp += PAGE_SIZE) {
375 		*cp = 'x';
376 	}
377 
378 	int fd = open("/tmp/file1", O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0644);
379 	T_ASSERT_TRUE(fd > 0, "File open successful");
380 	T_ASSERT_TRUE(((fcntl(fd, F_NOCACHE, 1)) != -1), "Setting F_NOCACHE");
381 	ssize_t ret = pwrite(fd, address, size, 0);
382 	T_ASSERT_TRUE((uint64_t) ret == size, "pwrite() on tagged memory");
383 
384 	char *incorrectly_tagged = __arm_mte_increment_tag(address, 1);
385 	ret = pwrite(fd, incorrectly_tagged, size, 0);
386 	T_ASSERT_TRUE((uint64_t) ret == size, "pwrite() on incorrectly tagged memory passes with direct I/O");
387 
388 	free(address);
389 #endif
390 }
391 
392 T_DECL(mte_tagged_memory_copy_io,
393     "Test direct I/O on tagged memory",
394     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
395     XNU_T_META_SOC_SPECIFIC)
396 {
397 #if !__arm64__
398 	T_SKIP("Running on non-arm64 target, skipping...");
399 #else /* !__arm64__ */
400 
401 	uint64_t size = PAGE_SIZE;
402 	char* address = (char*) malloc(size);
403 
404 	char *cp;
405 	for (cp = (char *) (address); cp < (char *) (address + size); cp += PAGE_SIZE) {
406 		*cp = 'x';
407 	}
408 
409 	int fd = open("/tmp/file1", O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0644);
410 	T_ASSERT_TRUE(fd > 0, "File open successful");
411 	ssize_t ret = pwrite(fd, address, size, 0);
412 	T_ASSERT_TRUE((uint64_t) ret == size, "pwrite() on tagged memory");
413 
414 	char *incorrectly_tagged = __arm_mte_increment_tag(address, 1);
415 	expect_sigkill(^{
416 		(void)pwrite(fd, incorrectly_tagged, size, 0);
417 	}, "copy I/O on wrongly tagged memory");
418 
419 	free(address);
420 #endif
421 }
422 
423 
424 static int FORK_TEST_CHILD_WRITES_FIRST = 0x1;
425 static int FORK_TEST_CHILD_FORKS = 0x2;
426 static int FORK_TEST_CHILD_RETAGS = 0x4;
427 static void
do_fork_test(vm_size_t vm_alloc_sz,int flags)428 do_fork_test(vm_size_t vm_alloc_sz, int flags)
429 {
430 #if !__arm64__
431 	T_SKIP("Running on non-arm64 target, skipping...");
432 #else /* !__arm64__ */
433 	vm_address_t address = 0;
434 	kern_return_t kr = vm_allocate(mach_task_self(), &address, vm_alloc_sz, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
435 
436 	T_ASSERT_MACH_SUCCESS(kr, "allocate tagged memory");
437 
438 	char *untagged_ptr = (char *)address;
439 	char *orig_tagged_ptr = __arm_mte_get_tag(untagged_ptr);
440 	uint64_t mask = __arm_mte_exclude_tag(orig_tagged_ptr, 0);
441 
442 	size_t count;
443 	size_t offset;
444 	const vm_size_t NUM_GRANULES = vm_alloc_sz / MTE_GRANULE_SIZE;
445 	char *tagged_ptrs[NUM_GRANULES];
446 
447 	/*
448 	 * Tag the entire page
449 	 */
450 	for (count = 0; count < NUM_GRANULES; count++) {
451 		offset = count * MTE_GRANULE_SIZE;
452 		tagged_ptrs[count] = __arm_mte_create_random_tag(untagged_ptr + offset, mask);
453 		__arm_mte_set_tag(tagged_ptrs[count]);
454 	}
455 
456 	if (!(flags & FORK_TEST_CHILD_WRITES_FIRST)) {
457 		for (count = 0; count < NUM_GRANULES; count++) {
458 			*(tagged_ptrs[count]) = 'a';
459 		}
460 	}
461 
462 	pid_t pid = fork();
463 	if (pid == 0) {
464 		T_LOG("Child forked");
465 
466 		if (flags & FORK_TEST_CHILD_RETAGS) {
467 			T_LOG("Child editing tags");
468 			/* re-tag the entire page */
469 			for (count = 0; count < NUM_GRANULES; count++) {
470 				tagged_ptrs[count] = __arm_mte_increment_tag(tagged_ptrs[count], 1);
471 				__arm_mte_set_tag(tagged_ptrs[count]);
472 			}
473 		}
474 
475 		T_LOG("Accessing parent tagged memory");
476 		/*
477 		 * Make sure the child process also has tag checks enabled.
478 		 */
479 		for (count = 0; count < NUM_GRANULES; count++) {
480 			*(tagged_ptrs[count]) = 'a';
481 		}
482 
483 		T_LOG("Child access to tagged memory success");
484 
485 		expect_sigkill(^{
486 			*untagged_ptr = 'b';
487 		}, "Child access through untagged ptr");
488 
489 		if (flags & FORK_TEST_CHILD_FORKS) {
490 			pid_t pid2 = fork();
491 
492 			if (pid2 == 0) {
493 				T_LOG("Grandchild forked");
494 
495 				T_LOG("Accessing grandparent's tagged memory");
496 
497 				for (count = 0; count < NUM_GRANULES; count++) {
498 					*(tagged_ptrs[count]) = 'a';
499 				}
500 
501 				T_LOG("Grandchild access to tagged memory success");
502 
503 				pid_t pid3 = fork();
504 
505 				if (pid3 == 0) {
506 					T_LOG("Great grandchild forked");
507 
508 					T_LOG("Accessing great grandparent's tagged memory");
509 
510 					for (count = 0; count < NUM_GRANULES; count++) {
511 						*(tagged_ptrs[count]) = 'a';
512 					}
513 
514 					T_LOG("Great grandchild access to tagged memory success");
515 
516 					kr = vm_deallocate(mach_task_self(), address, vm_alloc_sz);
517 					T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "Great grandchild vm_deallocate");
518 					exit(0);
519 				} else {
520 					T_ASSERT_TRUE(pid3 != -1, "Checking fork success in grandchild");
521 					int status2 = 0;
522 
523 					T_ASSERT_POSIX_SUCCESS(waitpid(pid3, &status2, 0), "waitpid");
524 					T_ASSERT_TRUE(WIFEXITED(status2) > 0, "Great grandchild exited normally");
525 				}
526 
527 				kr = vm_deallocate(mach_task_self(), address, vm_alloc_sz);
528 				T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "Grandchild vm_deallocate");
529 				exit(0);
530 			} else {
531 				T_ASSERT_TRUE(pid2 != -1, "Checking fork success in child");
532 				int status2 = 0;
533 				T_ASSERT_POSIX_SUCCESS(waitpid(pid2, &status2, 0), "waitpid");
534 				T_ASSERT_TRUE(WIFEXITED(status2) > 0, "Grandchild exited normally");
535 			}
536 		}
537 
538 		kr = vm_deallocate(mach_task_self(), address, vm_alloc_sz);
539 		T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "Child vm_deallocate");
540 		exit(0);
541 	} else {
542 		T_ASSERT_TRUE(pid != -1, "Checking fork success in parent");
543 
544 		int status = 0;
545 		T_ASSERT_POSIX_SUCCESS(waitpid(pid, &status, 0), "waitpid");
546 
547 		T_ASSERT_TRUE(WIFEXITED(status) > 0, "Child exited normally");
548 
549 		/* Verify that accessing memory actually works */
550 		for (count = 0; count < NUM_GRANULES; count++) {
551 			*(tagged_ptrs[count]) = 'a';
552 		}
553 
554 		T_LOG("Parent access to tagged memory sucessfull");
555 
556 		expect_sigkill(^{
557 			*untagged_ptr = 'b';
558 		}, "Parent access through untagged ptr");
559 	}
560 
561 	kr = vm_deallocate(mach_task_self(), address, vm_alloc_sz);
562 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "Parent vm_deallocate");
563 #endif
564 }
565 
566 T_DECL(mte_tag_check_fork_after_alloc_less_page_sz,
567     "Test MTE2 tag check fault in a child process after vm_allocate(ALLOC_SIZE, MTE)",
568     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
569     XNU_T_META_SOC_SPECIFIC)
570 {
571 	static const size_t ALLOC_SIZE = MTE_GRANULE_SIZE * 2;
572 	do_fork_test(ALLOC_SIZE, 0);
573 }
574 
575 T_DECL(mte_tag_check_fork_after_alloc_page_sz,
576     "Test MTE2 tag check fault in a child process after vm_allocate(PAGE_SIZE, MTE)",
577     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
578     XNU_T_META_SOC_SPECIFIC)
579 {
580 	do_fork_test(PAGE_SIZE, 0);
581 }
582 
583 /* NOTE: These following tests matter for when we switch to MEMORY_OBJECT_COPY_DELAY_FORK */
584 T_DECL(mte_tag_check_fork_child_fault_write,
585     "Test MTE2 tag check fault in a child process after vm_allocate(MTE) and child writes to tagged memory first",
586     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
587     XNU_T_META_SOC_SPECIFIC)
588 {
589 	do_fork_test(PAGE_SIZE, FORK_TEST_CHILD_WRITES_FIRST);
590 }
591 
592 T_DECL(mte_tag_check_fork_child_double_fork,
593     "Test MTE2 tag check fault in a child process after vm_allocate(MTE) and child writes to tagged memory first and then forks again",
594     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
595     XNU_T_META_SOC_SPECIFIC)
596 {
597 	do_fork_test(PAGE_SIZE, FORK_TEST_CHILD_WRITES_FIRST | FORK_TEST_CHILD_FORKS);
598 }
599 
600 /*
601  * These cases specifically test that tag setting instructions (STG) resolve CoW
602  * on fork correctly, since the child doesn't fault in the mapping by writing first.
603  */
604 T_DECL(mte_tag_check_fork_child_retag,
605     "Test MTE2 tag check fault in a child process after vm_allocate(MTE) and child changes tags",
606     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
607     XNU_T_META_SOC_SPECIFIC)
608 {
609 	do_fork_test(PAGE_SIZE, FORK_TEST_CHILD_RETAGS);
610 }
611 
612 T_DECL(mte_tag_check_fork_child_fault_write_retag,
613     "Test MTE2 tag check fault in a child process after vm_allocate(MTE) and child changes tags and writes to tagged memory first",
614     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
615     XNU_T_META_SOC_SPECIFIC)
616 {
617 	do_fork_test(PAGE_SIZE, FORK_TEST_CHILD_WRITES_FIRST | FORK_TEST_CHILD_RETAGS);
618 }
619 
620 T_DECL(mte_tag_check_fork_child_fault_write_retag_double_fork,
621     "Test MTE2 tag check fault in a child process after vm_allocate(MTE) and child changes tags, writes to tagged memory first, and then forks again",
622     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
623     XNU_T_META_SOC_SPECIFIC)
624 {
625 	do_fork_test(PAGE_SIZE, FORK_TEST_CHILD_WRITES_FIRST | FORK_TEST_CHILD_RETAGS | FORK_TEST_CHILD_FORKS);
626 }
627 
628 
629 T_DECL(mte_userland_uses_fake_kernel_pointer,
630     "Test that VM correctly rejects kernel-looking pointer from userspace",
631     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
632     XNU_T_META_SOC_SPECIFIC,
633     T_META_ENABLED(__arm64__))
634 {
635 #if __arm64__
636 	/*
637 	 * When the VM is given a user address that looks like a kernel pointer,
638 	 * we want to make sure that it still gets canonicalized as a user address
639 	 * (rather than a valid kernel pointer).
640 	 * This should result in a nonsensical pointer that shouldn't exist in any
641 	 * VM map, so the memory access should fail.
642 	 */
643 	vm_address_t addr = 0;
644 	kern_return_t kr = vm_allocate(
645 		mach_task_self(),
646 		&addr,
647 		MTE_GRANULE_SIZE,
648 		VM_FLAGS_ANYWHERE);
649 	T_QUIET;
650 	T_ASSERT_MACH_SUCCESS(kr, "allocate an untagged page");
651 	T_LOG("Allocated untagged page at addr: 0x%lx", addr);
652 
653 	/* Create a kernel-like pointer in userspace */
654 	char *tampered_ptr = (char *)(addr | VM_MIN_KERNEL_ADDRESS);
655 	T_LOG("Tampered ptr: %p", tampered_ptr);
656 
657 	/* segfault is expected, since the pointer is not valid in the userspace map */
658 	expect_signal(SIGSEGV, ^{
659 		*tampered_ptr = 'a';
660 	}, "Accessing kernel-like pointer from userspace");
661 	vm_deallocate(mach_task_self(), addr, MTE_GRANULE_SIZE);
662 #endif /* __arm64__ */
663 }
664 
665 /*
666  * Allocates tagged memory, assigns the memory a tag, and attempts to
667  * read the memory into its own address space via mach_vm_read().
668  *
669  * Also attempts to read the memory into its own address space with an untagged
670  * pointer, which we expect to fail.
671  */
672 static void
mte_mach_vm_read(mach_vm_size_t sz)673 mte_mach_vm_read(mach_vm_size_t sz)
674 {
675 	T_SETUPBEGIN;
676 	__block mach_vm_address_t addr = 0;
677 	__block vm_offset_t read_addr = 0;
678 	__block mach_msg_type_number_t read_size = 0;
679 
680 	mach_vm_size_t sz_rounded = (sz + (MTE_GRANULE_SIZE - 1)) & (unsigned)~((signed)(MTE_GRANULE_SIZE - 1));
681 	T_LOG("sz rounded: %llu", sz_rounded);
682 	/* Allocate some tagged memory */
683 	T_LOG("Allocate tagged memory");
684 	kern_return_t kr = mach_vm_allocate(
685 		mach_task_self(),
686 		&addr,
687 		sz_rounded,
688 		VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
689 	T_ASSERT_MACH_SUCCESS(kr, "Allocated tagged page");
690 	T_QUIET; T_ASSERT_NE_ULLONG(0ULL, addr, "Allocated address is not null");
691 
692 	uint64_t *untagged_ptr = (uint64_t *)addr;
693 
694 	uint64_t *orig_tagged_ptr = __arm_mte_get_tag(untagged_ptr);
695 	unsigned int orig_tag = extract_mte_tag(orig_tagged_ptr);
696 	T_QUIET; T_ASSERT_EQ_UINT(orig_tag, 0U, "Originally assigned tag is zero");
697 
698 	uint64_t mask = __arm_mte_exclude_tag(orig_tagged_ptr, 0);
699 	T_QUIET; T_EXPECT_EQ_LLONG(mask, (1ULL << 0), "Zero tag is excluded");
700 
701 	/* Generate random tag */
702 	uint64_t *tagged_ptr = NULL;
703 	tagged_ptr = __arm_mte_create_random_tag(untagged_ptr, mask);
704 	T_QUIET; T_EXPECT_NE_PTR(orig_tagged_ptr, tagged_ptr,
705 	    "Random tag was not taken from excluded tag set");
706 
707 	/* Time to make things real, commit the tag to memory */
708 	for (uintptr_t cur_ptr = (uintptr_t)tagged_ptr;
709 	    cur_ptr < (uintptr_t)tagged_ptr + sz_rounded;
710 	    cur_ptr += MTE_GRANULE_SIZE) {
711 		__arm_mte_set_tag((void *)cur_ptr);
712 	}
713 	T_LOG("Commited tagged pointer to memory: %p", tagged_ptr);
714 
715 	/* Write to the memory */
716 	for (uint i = 0; i < sz_rounded / sizeof(uint64_t); ++i) {
717 		tagged_ptr[i] = addr;
718 	}
719 	T_LOG("Wrote to memory");
720 	T_SETUPEND;
721 
722 	T_LOG("Reading %llu bytes from %p", sz, tagged_ptr);
723 	kr = mach_vm_read(
724 		mach_task_self(),
725 		(mach_vm_address_t)tagged_ptr,
726 		sz,
727 		&read_addr,
728 		&read_size);
729 	T_ASSERT_EQ(kr, KERN_SUCCESS,
730 	    "mach_vm_read %llu bytes from tagged ptr", sz);
731 
732 	/* Make sure we get the same thing back */
733 	T_ASSERT_EQ_UINT((unsigned int)sz, read_size,
734 	    "sz:%llu == read_size:%d", sz, read_size);
735 	int result = memcmp(tagged_ptr, (void *)read_addr, sz);
736 	T_ASSERT_EQ(result, 0, "mach_vm_read back the same info");
737 
738 	/* Now try with incorrectly tagged pointer (aka, no tag) */
739 	uint64_t *random_tagged_ptr = NULL;
740 	/* Exclude the previous tag */
741 	unsigned int previous_tag = extract_mte_tag(tagged_ptr);
742 	mask = __arm_mte_exclude_tag(tagged_ptr, previous_tag);
743 	random_tagged_ptr = __arm_mte_create_random_tag(untagged_ptr, mask);
744 	T_LOG("random tagged ptr: %p", random_tagged_ptr);
745 	T_EXPECT_NE_PTR(tagged_ptr, random_tagged_ptr,
746 	    "Random tag was not taken from excluded tag set");
747 
748 	T_LOG("Reading %llu bytes from %p", sz, random_tagged_ptr);
749 	expect_sigkill(^{
750 		T_LOG("tagged_ptr[0]: %llu", random_tagged_ptr[0]);
751 	}, "Accessing memory with the wrong tag, should fail");
752 
753 	expect_sigkill(^{
754 		(void)mach_vm_read(
755 			mach_task_self(),
756 			(mach_vm_address_t)random_tagged_ptr,
757 			KERNEL_BUFFER_COPY_THRESHOLD,
758 			&read_addr,
759 			&read_size);
760 	}, "Untagged pointer access leads to tag check fault");
761 
762 	/* Reset tags to 0 before freeing */
763 	for (uintptr_t cur_ptr = (uintptr_t)orig_tagged_ptr;
764 	    cur_ptr < (uintptr_t)orig_tagged_ptr + sz_rounded;
765 	    cur_ptr += MTE_GRANULE_SIZE) {
766 		__arm_mte_set_tag((void *)cur_ptr);
767 	}
768 	vm_deallocate(mach_task_self(), addr, sz_rounded);
769 }
770 
771 T_DECL(mte_mach_vm_read_16b,
772     "mach_vm_read 16 bytes of tagged memory",
773     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
774     XNU_T_META_SOC_SPECIFIC,
775     T_META_ENABLED(__arm64__))
776 {
777 #if __arm64__
778 	mte_mach_vm_read(MTE_GRANULE_SIZE);
779 #endif /* __arm64__ */
780 }
781 
782 T_DECL(mte_mach_vm_read_32k,
783     "mach_vm_read 32k bytes of tagged memory",
784     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
785     XNU_T_META_SOC_SPECIFIC,
786     T_META_ENABLED(__arm64__))
787 {
788 #if __arm64__
789 	mte_mach_vm_read(KERNEL_BUFFER_COPY_THRESHOLD);
790 #endif /* __arm64__ */
791 }
792 
793 T_DECL(mte_mach_vm_read_over_32k,
794     "mach_vm_read 32k + 1 bytes of tagged memory",
795     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
796     XNU_T_META_SOC_SPECIFIC,
797     T_META_ENABLED(__arm64__))
798 {
799 #if __arm64__
800 	/* This will actually get rounded to 32K + 16 */
801 	mte_mach_vm_read(KERNEL_BUFFER_COPY_THRESHOLD + 1);
802 #endif /* __arm64__ */
803 }
804 
805 T_DECL(mte_vm_map_copyinout_in_kernel,
806     "Test that the VM handles vm_map_copyin correctly for kernel-to-kernel tagged memory",
807     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
808     XNU_T_META_SOC_SPECIFIC,
809     T_META_ASROOT(true),
810     T_META_ENABLED(__arm64__))
811 {
812 #if __arm64__
813 	T_SKIP("This test is expected to panic; comment this line to be able to run it at desk.");
814 	(void) run_sysctl_test("vm_map_copyio", 0);
815 #endif /* __arm64__ */
816 }
817 
818 #if __arm64__
819 static void
do_remap_test(bool own_memory)820 do_remap_test(bool own_memory)
821 {
822 	mach_vm_address_t tagged_addr, untagged_addr;
823 	mach_vm_size_t size = PAGE_SIZE;
824 
825 	T_LOG("Allocate tagged memory");
826 	tagged_addr = allocate_and_tag_range(size, TAG_RANDOM);
827 	char *tagged_ptr = (char*) tagged_addr;
828 	untagged_addr = tagged_addr & ~MTE_TAG_MASK;
829 
830 	/* Write to the memory */
831 	for (unsigned int i = 0; i < size; i++) {
832 		tagged_ptr[i] = 'a';
833 	}
834 
835 	T_LOG("Wrote to memory");
836 
837 	expect_normal_exit(^{
838 		kern_return_t kr;
839 		mach_port_t port;
840 		if (own_memory) {
841 		        port = mach_task_self();
842 		} else {
843 		        /* note: expect_normal_exit forks, so the parent has the allocation as well */
844 		        kr = task_for_pid(mach_task_self(), getppid(), &port);
845 		        T_ASSERT_MACH_SUCCESS(kr, "task_for_pid");
846 		}
847 
848 		mach_vm_address_t remap_addr = 0;
849 		vm_prot_t curprot = VM_PROT_WRITE | VM_PROT_READ;
850 		vm_prot_t maxprot = VM_PROT_WRITE | VM_PROT_READ;
851 		kr = mach_vm_remap_new(mach_task_self(), &remap_addr, size,
852 		/* mask = */ 0, VM_FLAGS_ANYWHERE, port, untagged_addr,
853 		/* copy = */ FALSE, &curprot, &maxprot, VM_INHERIT_DEFAULT);
854 		T_ASSERT_MACH_SUCCESS(kr, "successfully remapped tagged memory");
855 
856 		T_ASSERT_EQ(remap_addr & MTE_TAG_MASK, 0ULL, "vm_remap returns an untagged pointer");
857 
858 		char *untagged_remap_ptr = (char*) remap_addr;
859 		char *tagged_remap_ptr = __arm_mte_get_tag(untagged_remap_ptr);
860 		char *incorrectly_tagged_remap_ptr = __arm_mte_increment_tag(tagged_remap_ptr, 1);
861 
862 		/* verify the data is correct; check every granule for speed */
863 		for (unsigned int i = 0; i < size; i += MTE_GRANULE_SIZE) {
864 		        T_QUIET; T_EXPECT_EQ(tagged_remap_ptr[i], 'a', "read value %u from array", i);
865 		}
866 		T_LOG("Verified data from child");
867 
868 		/* make sure the new mapping is also tagged */
869 		expect_sigkill(^{
870 			*untagged_remap_ptr = 'b';
871 		}, "remapped MTE memory sends SIGKILL when accessed with canonical tag");
872 		expect_sigkill(^{
873 			*incorrectly_tagged_remap_ptr = 'b';
874 		}, "remapped MTE memory sends SIGKILL when accessed with incorrect tag");
875 		expect_normal_exit(^{
876 			*tagged_remap_ptr = 'b';
877 		}, "remapped MTE memory can be accessed with correct tag");
878 
879 		if (!own_memory) {
880 		        kr = mach_port_deallocate(mach_task_self(), port);
881 		        T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "deallocate parent port");
882 		}
883 		kr = mach_vm_deallocate(mach_task_self(), remap_addr, size);
884 		T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "deallocate remapped memory");
885 		kr = mach_vm_deallocate(mach_task_self(), untagged_addr, size);
886 		T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "deallocate original memory from child");
887 	}, "remap tagged memory");
888 	kern_return_t kr = mach_vm_deallocate(mach_task_self(), untagged_addr, size);
889 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "deallocate original memory");
890 }
891 
892 T_DECL(mte_vm_map_remap_self,
893     "mach_vm_remap_new() on a tagged memory of the same process",
894     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
895     XNU_T_META_SOC_SPECIFIC,
896     T_META_ENABLED(__arm64__))
897 {
898 	do_remap_test(true);
899 }
900 
901 T_DECL(mte_vm_map_remap_other,
902     "mach_vm_remap_new() on a tagged memory of a different process",
903     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
904     XNU_T_META_SOC_SPECIFIC,
905     T_META_ENABLED(__arm64__))
906 {
907 	do_remap_test(false);
908 }
909 
910 #endif /* __arm64__ */
911 
912 T_DECL(vm_allocate_zero_tags,
913     "Ensure tags are zeroed when tagged memory is allocated from userspace",
914     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
915     XNU_T_META_SOC_SPECIFIC)
916 {
917 #if !__arm64__
918 	T_SKIP("Running on non-arm64 target, skipping...");
919 #else /* !__arm64__ */
920 	/*
921 	 * Do a bunch of allocations and check that the returned tags are zeroed.
922 	 * We do NUM_ALLOCATIONS_PER_ITERATION allocations, check the tags,
923 	 * deallocate them, and then do it again for a total of NUM_ITERATIONS
924 	 * iterations.
925 	 * NUM_ALLOCATIONS_PER_ITERATION is equal to the array bound.
926 	 */
927 	vm_address_t addresses[1000];
928 	const unsigned int NUM_ALLOCATIONS_PER_ITERATION = sizeof(addresses) / sizeof(addresses[0]);
929 	const unsigned int NUM_ITERATIONS = 3;
930 
931 	kern_return_t kr;
932 	for (size_t i = 0; i < NUM_ITERATIONS; i++) {
933 		unsigned int failures = 0;
934 		for (size_t j = 0; j < NUM_ALLOCATIONS_PER_ITERATION; j++) {
935 			kr = vm_allocate(mach_task_self(), &addresses[j], MTE_GRANULE_SIZE, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
936 			T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "allocate tagged memory (%zu, %zu)", i, j);
937 
938 			/*
939 			 * This is the actual test - we get the correctly tagged pointer and
940 			 * verify that it is zero.
941 			 */
942 			char *tagged_ptr = __arm_mte_get_tag((char*) addresses[j]);
943 			unsigned int orig_tag = extract_mte_tag(tagged_ptr);
944 			T_QUIET; T_EXPECT_EQ(orig_tag, 0, "vm_allocate returns memory with zeroed tags (%zu, %zu)", i, j);
945 			failures += (orig_tag != 0);
946 
947 			/* Assign an arbitrary nonzero tag and commit it to memory */
948 			tagged_ptr = __arm_mte_create_random_tag(tagged_ptr, 1);
949 			__arm_mte_set_tag(tagged_ptr);
950 
951 			/* Fail early if a zero tag was somehow assigned */
952 			unsigned int new_tag = extract_mte_tag(tagged_ptr);
953 			T_QUIET; T_ASSERT_NE(new_tag, 0, "random tag is nonzero (%zu, %zu)", i, j);
954 		}
955 
956 		for (size_t j = 0; j < NUM_ALLOCATIONS_PER_ITERATION; j++) {
957 			kr = vm_deallocate(mach_task_self(), addresses[j], MTE_GRANULE_SIZE);
958 			T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "deallocate tagged memory (%zu, %zu)", i, j);
959 		}
960 		/* Aggregate results per iteration to avoid too much noise */
961 		T_EXPECT_EQ(failures, 0, "Iteration %zu success", i);
962 	}
963 #endif /* !__arm64__ */
964 }
965 
966 /*
967  * Policy (MTE_VMSEC_13): VM performed range-checks must be done with
968  * canonicalized pointers, regardless of whether MTE is enabled
969  *
970  * Note that this specifically tests vm_map_copyin, vm_map_copy_overwrite,
971  * since those kernel functions are intended to take tagged pointers.
972  */
973 T_DECL(mte_copy_range_checks,
974     "Test that VM range checks operate on canonicalized pointers",
975     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
976     XNU_T_META_SOC_SPECIFIC)
977 {
978 #if !__arm64__
979 	T_SKIP("Running on non-arm64 target, skipping...");
980 #else /* !__arm64__ */
981 	vm_address_t tagged_addr, incorrectly_tagged_addr;
982 	/*
983 	 * Test setup
984 	 */
985 	const mach_vm_size_t alloc_size = PAGE_SIZE;
986 	tagged_addr = allocate_and_tag_range(alloc_size, 1);
987 	incorrectly_tagged_addr = (tagged_addr & ~MTE_TAG_MASK) | (2LLU << MTE_TAG_SHIFT);
988 
989 	/*
990 	 * mach_vm_copyin test:
991 	 * If mach_vm_copyin canonicalizes the tagged pointer for its range checks
992 	 * like it should, the range check will succeed and the actual "copy-in"
993 	 * operation will be allowed to go through. This will result in a tag check
994 	 * fault and the process being killed since the tag is incorrect.
995 	 *
996 	 * If, erroneously, the range check is done on tagged pointers, we expect
997 	 * to see a failure since the "incorrect" tag is larger than the "correct"
998 	 * one so it would be treated as out-of-bounds for the map.
999 	 */
1000 
1001 	expect_sigkill(^{
1002 		pointer_t read_address;
1003 		mach_msg_type_number_t read_size;
1004 		kern_return_t kr = mach_vm_read(mach_task_self(), incorrectly_tagged_addr,
1005 		alloc_size, &read_address, &read_size);
1006 		T_LOG("SIGKILL not received, kr was %d", kr);
1007 	}, "mach_vm_read with incorrectly tagged pointer should cause a tag check fault");
1008 
1009 	/*
1010 	 * mach_vm_copy_overwrite test:
1011 	 * Essentially the same logic using mach_vm_write instead of mach_vm_read.
1012 	 * To be able to do a vm_map_write, we need to first set up a vm_map_copy_t,
1013 	 * which we can get from a correctly-executed vm_map_read.
1014 	 */
1015 	T_SETUPBEGIN;
1016 	pointer_t copy_address;
1017 	mach_msg_type_number_t copy_size;
1018 	kern_return_t kr = mach_vm_read(mach_task_self(), tagged_addr,
1019 	    alloc_size, &copy_address, &copy_size);
1020 	T_ASSERT_MACH_SUCCESS(kr, "set up vm_map_copy_t for mach_vm_write test");
1021 	T_SETUPEND;
1022 	expect_sigkill(^{
1023 		kern_return_t kr2 = mach_vm_write(mach_task_self(), incorrectly_tagged_addr,
1024 		copy_address, copy_size);
1025 		T_LOG("SIGKILL not received, kr was %d", kr2);
1026 	}, "mach_vm_write with incorrectly tagged pointer should cause a tag check fault");
1027 #endif /* !__arm64__ */
1028 }
1029 
1030 /*
1031  * Policy (MTE_VMSEC_14): VM performed range math must be done using canonical
1032  * pointers, regardless of whether MTE is enabled.
1033  *
1034  * Note that this specifically tests vm_map_copyin, vm_map_copy_overwrite,
1035  * since those kernel functions are intended to take tagged pointers.
1036  */
1037 T_DECL(mte_copy_range_math,
1038     "Test that pointer values are not canonicalized after range math",
1039     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1040     XNU_T_META_SOC_SPECIFIC)
1041 {
1042 #if !__arm64__
1043 	T_SKIP("Running on non-arm64 target, skipping...");
1044 #else /* !__arm64__ */
1045 	vm_address_t tagged_addr;
1046 	kern_return_t kr;
1047 
1048 	/*
1049 	 * Test setup
1050 	 */
1051 	const mach_vm_size_t alloc_size = MTE_GRANULE_SIZE;
1052 	tagged_addr = allocate_and_tag_range(alloc_size, TAG_RANDOM);
1053 
1054 	vm_offset_t read_address;
1055 	mach_msg_type_number_t read_size;
1056 	mach_vm_size_t malformed_size;
1057 
1058 	/*
1059 	 * A size which extends into the MTE tag bits is too large to fit in
1060 	 * memory and should be rejected. If range math is operating on tagged
1061 	 * pointers (and the tag bits get stripped later), then this would
1062 	 * be accepted.
1063 	 */
1064 	// Test vm_map_copyin using mach_vm_read
1065 	malformed_size = (mach_vm_size_t) alloc_size | (7LLU << MTE_TAG_SHIFT);
1066 	kr = mach_vm_read(mach_task_self(), tagged_addr, malformed_size,
1067 	    &read_address, &read_size);
1068 	T_EXPECT_MACH_ERROR_(kr, KERN_INVALID_ARGUMENT, "mach_vm_read should reject size which extends into tag bits");
1069 
1070 	/*
1071 	 * Cannot test vm_map_copy_overwrite from userspace. The only entry point
1072 	 * that hits this function without first hitting mach_vm_read is
1073 	 * mach_vm_write, which takes its size as a 32-bit mach_msg_type_number_t.
1074 	 */
1075 #endif /* !__arm64__ */
1076 }
1077 
1078 /*
1079  * Policy (MTE_VMSEC_16): if the parameter/target of a VM API is a range of
1080  * memory, VM APIs must ensure that the address is not tagged
1081  *
1082  * Corollary: to ease adoption in cases in which pointers obtained from
1083  * the memory allocator are directly passed to some of these functions,
1084  * we implement stripping at the kernel API entrypoint for APIs that do
1085  * not affect the VM state or that are safe and common enough to strip.
1086  * This helps also clearing/making deterministic
1087  * cases where addresses were passed along the VM subsystem just waiting
1088  * to eventually be rejected.
1089  *
1090  * note: this does not apply to APIs which lead to vm_map_copy{in,out}, since
1091  * these need tags to be able to read tagged memory.
1092  */
1093 T_DECL(mte_vm_reject_tagged_pointers,
1094     "Test that most VM APIs reject tagged pointers",
1095     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1096     XNU_T_META_SOC_SPECIFIC,
1097     T_META_ASROOT(true) /* to be able to get host_priv port for mach_vm_wire */)
1098 {
1099 #if !__arm64__
1100 	T_SKIP("Running on non-arm64 target, skipping...");
1101 #else /* !__arm64__ */
1102 	vm_address_t untagged_addr, tagged_addr, tagged_addr_mprotect;
1103 	void *untagged_ptr, *tagged_ptr, *tagged_ptr_mprotect;
1104 	kern_return_t kr;
1105 	int ret;
1106 
1107 	/*
1108 	 * Test setup
1109 	 */
1110 	const size_t alloc_size = PAGE_SIZE;
1111 	tagged_addr = allocate_and_tag_range(alloc_size, TAG_RANDOM);
1112 	tagged_addr_mprotect = allocate_and_tag_range(alloc_size, TAG_RANDOM);
1113 	untagged_addr = tagged_addr & ~MTE_TAG_MASK;
1114 	untagged_ptr = (void*) untagged_addr;
1115 	tagged_ptr = (void*) tagged_addr;
1116 	tagged_ptr_mprotect = (void *)tagged_addr_mprotect;
1117 
1118 	T_QUIET; T_ASSERT_NE(tagged_addr & MTE_TAG_MASK, 0ULL, "validate tagged_addr");
1119 	T_QUIET; T_ASSERT_EQ(untagged_addr & MTE_TAG_MASK, 0ULL, "validate untagged_addr");
1120 
1121 	__block struct vm_region_submap_info_64 region_info;
1122 	void (^get_region_info)(void) = ^{
1123 		vm_address_t address = untagged_addr;
1124 		unsigned int depth = 1;
1125 		vm_size_t size;
1126 		mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
1127 		kern_return_t region_kr = vm_region_recurse_64(mach_task_self(), &address, &size,
1128 		    &depth, (vm_region_info_t) &region_info, &count);
1129 		T_QUIET; T_ASSERT_MACH_SUCCESS(region_kr, "get allocation region info");
1130 	};
1131 
1132 	/*
1133 	 * Test various APIs with tagged pointers
1134 	 */
1135 	/* mprotect, mach_vm_protect are common enough, we strip implicitly. */
1136 	ret = mprotect(tagged_ptr_mprotect, alloc_size, PROT_NONE);
1137 	T_EXPECT_POSIX_SUCCESS(ret, "mprotect");
1138 	kr = mach_vm_protect(mach_task_self(), tagged_addr_mprotect, alloc_size, false, PROT_NONE);
1139 	T_EXPECT_MACH_SUCCESS(kr, "mach_vm_protect");
1140 
1141 	/*
1142 	 * mincore: SUCCESS
1143 	 */
1144 	char vec[100] = {0};
1145 	T_QUIET; T_ASSERT_LE(alloc_size, sizeof(vec) * PAGE_SIZE, "vec is large enough to fit mincore result");
1146 	ret = mincore(tagged_ptr, alloc_size, vec);
1147 	T_EXPECT_POSIX_SUCCESS(ret, "mincore: return value");
1148 
1149 	/* msync, mach_vm_msync */
1150 	ret = msync(tagged_ptr, alloc_size, MS_SYNC);
1151 	T_EXPECT_POSIX_SUCCESS(ret, "msync");
1152 	kr = mach_vm_msync(mach_task_self(), tagged_addr, alloc_size, VM_SYNC_SYNCHRONOUS | VM_SYNC_CONTIGUOUS);
1153 	T_EXPECT_MACH_SUCCESS(kr, "mach_vm_msync");
1154 
1155 	/* madvise, mach_vm_behavior_set strip tagged addresses */
1156 	ret = madvise(tagged_ptr, alloc_size, MADV_NORMAL);
1157 	T_EXPECT_POSIX_SUCCESS(ret, "madvise");
1158 	kr = mach_vm_behavior_set(mach_task_self(), tagged_addr, alloc_size,
1159 	    VM_BEHAVIOR_DEFAULT);
1160 	T_EXPECT_MACH_SUCCESS(kr, "mach_vm_behavior_set");
1161 
1162 	/*
1163 	 * minherit, mach_vm_inherit:
1164 	 * mach_vm_inherit would just silently succeed and do nothing if the range was tagged, so
1165 	 * we strip addresses to have consistent behavior.
1166 	 */
1167 	const vm_inherit_t NEW_INHERIT = VM_INHERIT_NONE;
1168 	ret = minherit(tagged_ptr, alloc_size, NEW_INHERIT);
1169 	T_EXPECT_POSIX_SUCCESS(ret, "minherit");
1170 	kr = mach_vm_inherit(mach_task_self(), tagged_addr, alloc_size, NEW_INHERIT);
1171 	T_EXPECT_MACH_SUCCESS(kr, "mach_vm_inherit");
1172 
1173 	/*
1174 	 * mlock, mach_vm_wire(prot != VM_PROT_NONE):
1175 	 * Allow implicitly stripping to avoid no-op success that might confuse third parties.
1176 	 */
1177 	mach_port_t host_priv = HOST_PRIV_NULL;
1178 	kr = host_get_host_priv_port(mach_host_self(), &host_priv); \
1179 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "get host_priv port");
1180 
1181 	ret = mlock(tagged_ptr, alloc_size);
1182 	T_EXPECT_POSIX_SUCCESS(ret, "mlock");
1183 	get_region_info();
1184 	T_EXPECT_EQ(region_info.user_wired_count, (unsigned short) 1, "mlock on tagged pointer should wire memory");
1185 	ret = munlock(tagged_ptr, alloc_size);
1186 	T_EXPECT_POSIX_SUCCESS(ret, "munlock");
1187 	get_region_info();
1188 	T_EXPECT_EQ(region_info.user_wired_count, (unsigned short) 0, "munlock on tagged pointer should unwire memory");
1189 
1190 	kr = mach_vm_wire(host_priv, mach_task_self(), tagged_addr,
1191 	    alloc_size, VM_PROT_DEFAULT);
1192 	T_EXPECT_MACH_SUCCESS(kr, "mach_vm_wire (wire)");
1193 	get_region_info();
1194 	T_EXPECT_EQ(region_info.user_wired_count, (unsigned short) 1, "mach_vm_wire on tagged address should wire memory");
1195 	ret = munlock(tagged_ptr, alloc_size);
1196 	T_EXPECT_POSIX_SUCCESS(ret, "munlock");
1197 
1198 	/* List of flags used to test vm_allocate, vm_map and vm_remap */
1199 	const int ALLOCATE_FLAGS[] = {
1200 		VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE,
1201 		VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE | VM_FLAGS_MTE,
1202 		VM_FLAGS_ANYWHERE,
1203 		VM_FLAGS_ANYWHERE | VM_FLAGS_MTE
1204 	};
1205 	const size_t NUM_ALLOCATE_FLAGS = sizeof(ALLOCATE_FLAGS) / sizeof(*ALLOCATE_FLAGS);
1206 
1207 	/* vm_allocate tests: */
1208 	for (size_t i = 0; i < NUM_ALLOCATE_FLAGS; i++) {
1209 		mach_vm_address_t new_addr = tagged_addr;
1210 		kr = mach_vm_allocate(mach_task_self(), &new_addr, alloc_size, ALLOCATE_FLAGS[i]);
1211 		if (ALLOCATE_FLAGS[i] & VM_FLAGS_ANYWHERE) {
1212 			T_EXPECT_MACH_SUCCESS(kr, "mach_vm_allocate %zu (%#x)", i, ALLOCATE_FLAGS[i]);
1213 			T_QUIET; T_EXPECT_EQ(new_addr & MTE_TAG_MASK, 0ull, "mach_vm_allocate should return untagged pointer");
1214 			T_QUIET; T_EXPECT_NE((vm_address_t) new_addr, untagged_addr, "allocate anywhere should return a new range");
1215 
1216 			/* clean up new allocation */
1217 			if (kr == KERN_SUCCESS) {
1218 				kr = mach_vm_deallocate(mach_task_self(), new_addr, alloc_size);
1219 				T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "cleanup mach_vm_map");
1220 			}
1221 		} else {
1222 			T_EXPECT_MACH_ERROR(kr, KERN_INVALID_ADDRESS, "mach_vm_allocate %zu (%#x)", i, ALLOCATE_FLAGS[i]);
1223 		}
1224 	}
1225 
1226 	/* mach_vm_machine_attribute: allow tagged addresses */
1227 	vm_machine_attribute_val_t machine_attribute_val = MATTR_VAL_CACHE_FLUSH;
1228 	kr = mach_vm_machine_attribute(mach_task_self(), tagged_addr, alloc_size,
1229 	    MATTR_CACHE, &machine_attribute_val);
1230 	T_EXPECT_MACH_SUCCESS(kr, "mach_vm_machine_attribute");
1231 
1232 	/* mach_make_memory_entry_64: DO NOT allow tagged addresses */
1233 	mach_port_t object_handle;
1234 	memory_object_size_t object_size = alloc_size;
1235 	kr = mach_make_memory_entry_64(mach_task_self(), &object_size, tagged_addr,
1236 	    VM_PROT_DEFAULT, &object_handle, MACH_PORT_NULL);
1237 	T_EXPECT_MACH_ERROR(kr, KERN_INVALID_ADDRESS, "mach_make_memory_entry_64");
1238 
1239 	/* mach_vm_map: DO NOT allow tagged addresses */
1240 	/* setup: get a memory entry to map in */
1241 	kr = mach_make_memory_entry_64(mach_task_self(), &object_size, untagged_addr,
1242 	    VM_PROT_DEFAULT | MAP_MEM_NAMED_CREATE, &object_handle, MACH_PORT_NULL);
1243 	T_ASSERT_MACH_SUCCESS(kr, "create memory entry for mach_vm_map");
1244 
1245 	for (size_t i = 0; i < NUM_ALLOCATE_FLAGS; i++) {
1246 		mach_vm_address_t new_addr = tagged_addr;
1247 		kr = mach_vm_map(mach_task_self(), &new_addr, alloc_size, /* mask = */ 0,
1248 		    ALLOCATE_FLAGS[i], object_handle, /* offset = */ 0, /* copy = */ true,
1249 		    VM_PROT_DEFAULT, VM_PROT_DEFAULT, VM_INHERIT_DEFAULT);
1250 		if (ALLOCATE_FLAGS[i] & VM_FLAGS_ANYWHERE) {
1251 			/*
1252 			 * VM_FLAGS_ANYWHERE uses the provided address as a location to start
1253 			 * searching from. Since a tagged address is outside the map bounds,
1254 			 * it won't be able to find any space for the allocation.
1255 			 */
1256 			T_EXPECT_MACH_ERROR(kr, KERN_NO_SPACE, "mach_vm_map %zu (%#x)", i, ALLOCATE_FLAGS[i]);
1257 		} else {
1258 			T_EXPECT_MACH_ERROR(kr, KERN_INVALID_ADDRESS, "mach_vm_map %zu (%#x)", i, ALLOCATE_FLAGS[i]);
1259 		}
1260 	}
1261 
1262 	/* clean up memory entry object handle */
1263 	kr = mach_port_deallocate(mach_task_self(), object_handle);
1264 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "mach_vm_map tests: clean up memory entry object handle");
1265 
1266 	/* mach_vm_purgable_control */
1267 	int purgable_state;
1268 	kr = mach_vm_purgable_control(mach_task_self(), tagged_addr, VM_PURGABLE_GET_STATE, &purgable_state);
1269 	T_EXPECT_MACH_ERROR(kr, KERN_INVALID_ADDRESS, "mach_vm_purgable_control");
1270 
1271 	/* mach_vm_region: reject tagged addresses */
1272 	mach_vm_address_t region_addr = tagged_addr;
1273 	mach_vm_size_t region_size;
1274 	vm_region_basic_info_data_64_t region_info_64;
1275 	mach_msg_type_number_t region_info_cnt = VM_REGION_BASIC_INFO_COUNT_64;
1276 	mach_port_t unused;
1277 
1278 	kr = mach_vm_region(mach_task_self(), &region_addr, &region_size,
1279 	    VM_REGION_BASIC_INFO_64, (vm_region_info_t) &region_info_64,
1280 	    &region_info_cnt, &unused);
1281 	T_EXPECT_MACH_ERROR(kr, KERN_INVALID_ADDRESS, "mach_vm_region");
1282 
1283 	/* mach_vm_remap_new */
1284 	mach_vm_address_t untagged_addr2, tagged_addr2;
1285 	tagged_addr2 = allocate_and_tag_range(alloc_size, TAG_RANDOM);
1286 	untagged_addr2 = tagged_addr2 & ~MTE_TAG_MASK;
1287 
1288 	/* Test each flag value twice, once with source tagged and once with destination tagged */
1289 	for (size_t i = 0; i < 2 * NUM_ALLOCATE_FLAGS; i++) {
1290 		int flags = ALLOCATE_FLAGS[i % NUM_ALLOCATE_FLAGS];
1291 		bool source_tagged = i < NUM_ALLOCATE_FLAGS;
1292 		char *msg = source_tagged ? "source tagged" : "dest tagged";
1293 		mach_vm_address_t src_addr = source_tagged ? tagged_addr : untagged_addr;
1294 		mach_vm_address_t dest_addr = source_tagged ? untagged_addr2 : tagged_addr2;
1295 
1296 		vm_prot_t cur_prot = VM_PROT_DEFAULT, max_prot = VM_PROT_DEFAULT;
1297 		kr = mach_vm_remap_new(mach_task_self(), &dest_addr, alloc_size, /* mask = */ 0,
1298 		    flags, mach_task_self(), src_addr, true, &cur_prot, &max_prot,
1299 		    VM_INHERIT_DEFAULT);
1300 
1301 		if (flags & VM_FLAGS_MTE) {
1302 			/* VM_FLAGS_USER_REMAP does not include VM_FLAGS_MTE */
1303 			T_EXPECT_MACH_ERROR(kr, KERN_INVALID_ARGUMENT, "mach_vm_remap_new %zu (%s, %#x)", i, msg, flags);
1304 		} else if (!source_tagged && flags & VM_FLAGS_ANYWHERE) {
1305 			/*
1306 			 * In this case, we pass vm_map_remap_extract since the source
1307 			 * address is untagged. When we try to find a space to insert it
1308 			 * into the map, we fail since VM_FLAGS_ANYWHERE uses the destination
1309 			 * passed in as a location to start searching from.
1310 			 */
1311 			T_EXPECT_MACH_ERROR(kr, KERN_NO_SPACE, "mach_vm_remap_new %zu (%s, %#x)", i, msg, flags);
1312 		} else {
1313 			T_EXPECT_MACH_ERROR(kr, KERN_INVALID_ADDRESS, "mach_vm_remap_new %zu (%s, %#x)", i, msg, flags);
1314 		}
1315 
1316 		if (kr == KERN_SUCCESS && (flags & VM_FLAGS_ANYWHERE)) {
1317 			/* clean up the new allocation if we mistakenly suceeded */
1318 			kr = mach_vm_deallocate(mach_task_self(), dest_addr, alloc_size);
1319 			T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "cleanup mach_vm_remap_new %zu (%s, %#x)", i, msg, flags);
1320 		}
1321 	}
1322 
1323 	/* clean up our second allocation */
1324 	T_SETUPBEGIN;
1325 	kr = vm_deallocate(mach_task_self(), untagged_addr2, alloc_size);
1326 	T_QUIET; T_EXPECT_MACH_SUCCESS(kr, "clean up allocation for mach_vm_remap_new tests");
1327 	T_SETUPEND;
1328 
1329 	/* vm_deallocate: vm_allocate() will return a canonical address, so we mandate a canonical address here */
1330 	T_SETUPBEGIN;
1331 	kr = vm_deallocate(mach_task_self(), tagged_addr, alloc_size);
1332 	T_EXPECT_MACH_ERROR(kr, KERN_INVALID_ARGUMENT, "vm_deallocate denies a non-canonical addresses");
1333 	T_SETUPEND;
1334 
1335 	/* test cleanup */
1336 	T_SETUPBEGIN;
1337 	kr = vm_deallocate(mach_task_self(), untagged_addr, alloc_size);
1338 	T_ASSERT_MACH_SUCCESS(kr, "test region cleanup");
1339 	T_SETUPEND;
1340 #endif /* !__arm64__ */
1341 }
1342 
1343 T_DECL(mte_tagged_page_relocation,
1344     "Test that VM copies tags on page relocation for tagged memory",
1345     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
1346     T_META_ASROOT(true),
1347     XNU_T_META_SOC_SPECIFIC,
1348     T_META_ENABLED(__arm64__))
1349 {
1350 #if __arm64__
1351 	T_SETUPBEGIN;
1352 	mach_vm_address_t addr = 0;
1353 	kern_return_t kr = mach_vm_allocate(
1354 		mach_task_self(),
1355 		&addr,
1356 		PAGE_SIZE,
1357 		VM_FLAGS_ANYWHERE | VM_FLAGS_MTE
1358 		);
1359 	T_ASSERT_MACH_SUCCESS(kr,
1360 	    "allocate 32 bytes of tagged memory at 0x%llx", addr);
1361 
1362 	/* Verify originally assigned tags are zero */
1363 	for (uint i = 0; i < PAGE_SIZE / MTE_GRANULE_SIZE; ++i) {
1364 		char *untagged_ptr = (char *)((uintptr_t)addr + i * MTE_GRANULE_SIZE);
1365 		char *orig_tagged_ptr = __arm_mte_get_tag(untagged_ptr);
1366 		unsigned int orig_tag = extract_mte_tag(orig_tagged_ptr);
1367 		T_QUIET; T_ASSERT_EQ_UINT(orig_tag, 0U, "originally assigned tag is zero");
1368 	}
1369 
1370 	/*
1371 	 * Tag the first 16 bytes with non-zero tag, and
1372 	 * leave the second 16 bytes as is
1373 	 */
1374 	char *untagged_ptr = (char *)addr;
1375 	char *orig_tagged_ptr = __arm_mte_get_tag(untagged_ptr);
1376 	uint64_t mask = __arm_mte_exclude_tag(orig_tagged_ptr, 0);
1377 	T_EXPECT_EQ_LLONG(mask, (1LL << 0), "zero tag is excluded");
1378 
1379 	char *random_tagged_ptr = __arm_mte_create_random_tag(untagged_ptr, mask);
1380 	T_QUIET; T_EXPECT_NE_PTR(orig_tagged_ptr, random_tagged_ptr,
1381 	    "random tag was not taken from excluded tag set");
1382 
1383 	ptrdiff_t diff = __arm_mte_ptrdiff(untagged_ptr, random_tagged_ptr);
1384 	T_QUIET; T_EXPECT_EQ_ULONG(diff, (ptrdiff_t)0, "untagged %p and tagged %p have identical address bits",
1385 	    untagged_ptr, random_tagged_ptr);
1386 
1387 	/* Time to make things real, commit the tag to memory */
1388 	__arm_mte_set_tag(random_tagged_ptr);
1389 
1390 	/* Ensure that we can read back the tag */
1391 	char *read_back = __arm_mte_get_tag(untagged_ptr);
1392 	T_EXPECT_EQ_PTR(read_back, random_tagged_ptr, "tag was committed to memory correctly");
1393 
1394 	T_LOG("tagged pointer: %p", random_tagged_ptr);
1395 	random_tagged_ptr[0] = 'a';
1396 	untagged_ptr[MTE_GRANULE_SIZE] = 'b';
1397 	T_SETUPEND;
1398 
1399 	/*
1400 	 * Relocate the page.
1401 	 * The kernel will also write 'b' and 'c' to the memory.
1402 	 */
1403 	int64_t ret = run_sysctl_test("vm_page_relocate", (int64_t)random_tagged_ptr);
1404 	T_EXPECT_EQ_LLONG(ret, 1LL, "sysctl: relocate page");
1405 
1406 	T_EXPECT_EQ_CHAR(random_tagged_ptr[0], 'b',
1407 	    "reading from tagged ptr after relocation");
1408 	T_EXPECT_EQ_CHAR(untagged_ptr[MTE_GRANULE_SIZE], 'c',
1409 	    "reading from untagged ptr after relocation");
1410 #endif /* __arm64__ */
1411 }
1412 
1413 T_HELPER_DECL(mte_tag_violate, "child process to trigger an MTE violation")
1414 {
1415 	static const size_t ALLOC_SIZE = MTE_GRANULE_SIZE * 2;
1416 
1417 	vm_address_t address = 0;
1418 	kern_return_t kr = vm_allocate(mach_task_self(), &address, ALLOC_SIZE, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
1419 	T_ASSERT_MACH_SUCCESS(kr, "allocate tagged memory");
1420 	char *untagged_ptr = (char *) address;
1421 
1422 	char *orig_tagged_ptr = __arm_mte_get_tag(untagged_ptr);
1423 	unsigned int orig_tag = extract_mte_tag(orig_tagged_ptr);
1424 	T_ASSERT_EQ_UINT(orig_tag, 0U, "originally assigned tag is zero");
1425 
1426 	uint64_t mask = __arm_mte_exclude_tag(orig_tagged_ptr, 0);
1427 	T_EXPECT_EQ_LLONG(mask, (1LL << 0), "zero tag is excluded");
1428 
1429 	char *random_tagged_ptr = NULL;
1430 	for (unsigned int i = 0; i < NUM_MTE_TAGS * 4; i++) {
1431 		random_tagged_ptr = __arm_mte_create_random_tag(untagged_ptr, mask);
1432 		T_QUIET; T_EXPECT_NE_PTR(orig_tagged_ptr, random_tagged_ptr,
1433 		    "random tag was not taken from excluded tag set");
1434 
1435 		ptrdiff_t diff = __arm_mte_ptrdiff(untagged_ptr, random_tagged_ptr);
1436 		T_QUIET; T_EXPECT_EQ_ULONG(diff, (ptrdiff_t)0, "untagged %p and tagged %p have identical address bits",
1437 		    untagged_ptr, random_tagged_ptr);
1438 	}
1439 
1440 	__arm_mte_set_tag(random_tagged_ptr);
1441 
1442 	char *read_back = __arm_mte_get_tag(untagged_ptr);
1443 	T_EXPECT_EQ_PTR(read_back, random_tagged_ptr, "tag was committed to memory correctly");
1444 
1445 	random_tagged_ptr[0] = 't';
1446 	random_tagged_ptr[1] = 'e';
1447 	random_tagged_ptr[2] = 's';
1448 	random_tagged_ptr[3] = 't';
1449 	T_EXPECT_EQ_STR(random_tagged_ptr, "test", "read/write from tagged memory");
1450 
1451 	void *next_granule_ptr = orig_tagged_ptr + MTE_GRANULE_SIZE;
1452 	unsigned int next_granule_tag = extract_mte_tag(next_granule_ptr);
1453 	T_QUIET; T_ASSERT_EQ_UINT(next_granule_tag, 0U,
1454 	    "next MTE granule still has its originally assigned tag");
1455 
1456 	T_LOG("attempting out-of-bounds access to tagged memory");
1457 	random_tagged_ptr[MTE_GRANULE_SIZE] = '!';
1458 	T_LOG("bypass: survived OOB access");
1459 
1460 	__arm_mte_set_tag(orig_tagged_ptr);
1461 	__arm_mte_set_tag(orig_tagged_ptr + MTE_GRANULE_SIZE);
1462 	vm_deallocate(mach_task_self(), address, ALLOC_SIZE);
1463 	exit(0);
1464 }
1465 
1466 T_HELPER_DECL(mte_copyio_bypass_helper, "child process to test copyio in MTE tag check bypass mode")
1467 {
1468 	run_mte_copyio_tests(false);
1469 }
1470 
1471 static void
run_helper_with_sec_bypass(char * helper_name)1472 run_helper_with_sec_bypass(char *helper_name)
1473 {
1474 	char path[PATH_MAX];
1475 	uint32_t path_size = sizeof(path);
1476 	T_ASSERT_POSIX_ZERO(_NSGetExecutablePath(path, &path_size), "_NSGetExecutablePath");
1477 	char *args[] = { path, "-n", helper_name, NULL };
1478 
1479 	pid_t child_pid = 0;
1480 	posix_spawnattr_t attr;
1481 	errno_t ret = posix_spawnattr_init(&attr);
1482 	T_ASSERT_POSIX_ZERO(ret, "posix_spawnattr_init");
1483 
1484 	ret = posix_spawnattr_set_use_sec_transition_shims_np(&attr, POSIX_SPAWN_SECFLAG_EXPLICIT_ENABLE | POSIX_SPAWN_SECFLAG_EXPLICIT_CHECK_BYPASS);
1485 	T_ASSERT_POSIX_ZERO(ret, "posix_spawnattr_set_use_sec_transition_shims_np");
1486 
1487 	ret = posix_spawn(&child_pid, path, NULL, &attr, args, NULL);
1488 	T_ASSERT_POSIX_ZERO(ret, "posix_spawn");
1489 	T_ASSERT_NE(child_pid, 0, "posix_spawn");
1490 
1491 	ret = posix_spawnattr_destroy(&attr);
1492 	T_ASSERT_POSIX_ZERO(ret, "posix_spawnattr_destroy");
1493 
1494 	int status = 0;
1495 	T_ASSERT_POSIX_SUCCESS(waitpid(child_pid, &status, 0), "waitpid");
1496 	T_EXPECT_TRUE(WIFEXITED(status), "exited successfully");
1497 	T_EXPECT_TRUE(WEXITSTATUS(status) == 0, "exited with status %d", WEXITSTATUS(status));
1498 }
1499 
1500 T_DECL(mte_tag_bypass,
1501     "Test MTE2 tag check bypass works with posix_spawnattr",
1502     T_META_ENABLED(TARGET_CPU_ARM64),
1503     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
1504     XNU_T_META_SOC_SPECIFIC)
1505 {
1506 	run_helper_with_sec_bypass("mte_tag_violate");
1507 }
1508 
1509 T_DECL(mte_copyio_bypass,
1510     "Test MTE2 tag check bypass with copyio operations",
1511     T_META_ENABLED(TARGET_CPU_ARM64),
1512     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE4", 1),
1513     XNU_T_META_SOC_SPECIFIC)
1514 {
1515 	run_helper_with_sec_bypass("mte_copyio_bypass_helper");
1516 }
1517 
1518 #ifdef __arm64__
1519 T_DECL(mte_read_only,
1520     "Verify that setting tags on a read-only mapping results in SIGBUS",
1521     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1522     XNU_T_META_SOC_SPECIFIC)
1523 {
1524 	uint64_t mask;
1525 	T_SETUPBEGIN;
1526 	void* untagged_ptr = allocate_tagged_memory(MTE_GRANULE_SIZE, &mask);
1527 	void *tagged_ptr = __arm_mte_create_random_tag(untagged_ptr, mask);
1528 	T_SETUPEND;
1529 
1530 	assert_normal_exit(^{
1531 		__arm_mte_set_tag(tagged_ptr);
1532 	}, "can set tags on writable memory");
1533 
1534 	int ret = mprotect(untagged_ptr, MTE_GRANULE_SIZE, PROT_READ);
1535 	T_ASSERT_POSIX_SUCCESS(ret, "mprotect");
1536 
1537 	tagged_ptr = __arm_mte_increment_tag(tagged_ptr, 1);
1538 
1539 	expect_signal(SIGBUS, ^{
1540 		__arm_mte_set_tag(tagged_ptr);
1541 	}, "set tag on read-only memory");
1542 
1543 	T_SETUPBEGIN;
1544 	kern_return_t kr = vm_deallocate(mach_task_self(), (vm_address_t) untagged_ptr, MTE_GRANULE_SIZE);
1545 	T_QUIET; T_EXPECT_MACH_SUCCESS(kr, "clean up tagged allocation");
1546 	T_SETUPEND;
1547 }
1548 
1549 T_DECL(mte_inherit_share,
1550     "Verify that you can't set VM_INHERIT_SHARE on tagged memory",
1551     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1552     XNU_T_META_SOC_SPECIFIC)
1553 {
1554 	const mach_vm_size_t ALLOC_SIZE = PAGE_SIZE;
1555 	__block kern_return_t kr;
1556 
1557 	T_SETUPBEGIN;
1558 	vm_address_t tagged_addr = allocate_and_tag_range(ALLOC_SIZE, TAG_RANDOM);
1559 	vm_address_t untagged_addr = tagged_addr & ~MTE_TAG_MASK;
1560 	T_SETUPEND;
1561 
1562 	expect_sigkill(^{
1563 		int ret = minherit((void*) untagged_addr, ALLOC_SIZE, VM_INHERIT_SHARE);
1564 		T_LOG("minherit: was not killed and returned %d", ret);
1565 	}, "minherit(VM_INHERIT_SHARE) on tagged memory");
1566 
1567 	expect_sigkill(^{
1568 		kr = mach_vm_inherit(mach_task_self(), untagged_addr,
1569 		ALLOC_SIZE, VM_INHERIT_SHARE);
1570 		T_LOG("mach_vm_inherit: was not killed and returned %d", kr);
1571 	}, "mach_vm_inherit(VM_INHERIT_SHARE) on tagged memory");
1572 
1573 	T_SETUPBEGIN;
1574 	kr = vm_deallocate(mach_task_self(), untagged_addr, ALLOC_SIZE);
1575 	T_QUIET; T_EXPECT_MACH_SUCCESS(kr, "clean up tagged allocation");
1576 	T_SETUPEND;
1577 
1578 	expect_sigkill(^{
1579 		mach_vm_address_t addr = 0;
1580 		kr = mach_vm_map(mach_task_self(), &addr, ALLOC_SIZE, /* mask = */ 0,
1581 		VM_FLAGS_ANYWHERE | VM_FLAGS_MTE, MACH_PORT_NULL, /* offset = */ 0,
1582 		/* copy = */ false, VM_PROT_DEFAULT, VM_PROT_ALL, VM_INHERIT_SHARE);
1583 		T_LOG("mach_vm_map: was not killed and returned %d", kr);
1584 
1585 		T_SETUPBEGIN;
1586 		kr = vm_deallocate(mach_task_self(), addr, ALLOC_SIZE);
1587 		T_QUIET; T_EXPECT_MACH_SUCCESS(kr, "clean up mach_vm_map allocation");
1588 		T_SETUPEND;
1589 	}, "mach_vm_map(VM_INHERIT_SHARE) to create new tagged memory");
1590 }
1591 
1592 static vm_object_id_t
get_object_id(mach_port_t task,vm_address_t addr)1593 get_object_id(mach_port_t task, vm_address_t addr)
1594 {
1595 	unsigned int depth = 1;
1596 	vm_size_t size;
1597 	struct vm_region_submap_info_64 info;
1598 	mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
1599 	kern_return_t kr = vm_region_recurse_64(task, &addr, &size, &depth,
1600 	    (vm_region_info_t) &info, &count);
1601 	/*
1602 	 * I'm not sure why it returns KERN_INVALID_ADDRESS in this case, but this
1603 	 * can happen if the corpse task goes away. That happens if a jetsam event
1604 	 * occurs (even on an unrelated process) while the test is running.
1605 	 */
1606 	if (task != mach_task_self() && kr == KERN_INVALID_ADDRESS) {
1607 		T_SKIP("corpse port disappeared, bailing...");
1608 	}
1609 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "get_object_id: vm_region_recurse_64");
1610 	return info.object_id_full;
1611 }
1612 
1613 T_DECL(mte_corpse_fork,
1614     "Verify that corpse-fork sharing paths work normally on tagged memory",
1615     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1616     XNU_T_META_SOC_SPECIFIC,
1617     /* rdar://138528295 (Provide a mechanism to guarantee availability of corpse slots for tests) */
1618     T_META_RUN_CONCURRENTLY(false))
1619 {
1620 	/*
1621 	 * The corpse-fork path shares memory in two additional cases:
1622 	 * (1) if the entry has INHERIT_NONE, and
1623 	 * (2) if the memory is "owned" by the process for accounting purposes. This
1624 	 * essentially means that it is purgeable & volatile.
1625 	 * We want to ensure that these cases are unaffected by MTE restrictions on
1626 	 * VM_INHERIT_SHARE.
1627 	 */
1628 	kern_return_t kr;
1629 	mach_vm_size_t alloc_size = PAGE_SIZE;
1630 	mach_vm_address_t inherit_none_addr, owned_addr, regular_addr;
1631 
1632 	T_SETUPBEGIN;
1633 
1634 	/* First up, expand the system's corpse pool size.
1635 	 * Otherwise, this test sporadically can't secure the corpse slots it needs.
1636 	 */
1637 	int original_total_corpses_allowed;
1638 	size_t original_total_corpses_allowed_sizeof = sizeof(original_total_corpses_allowed);
1639 	int total_corpses_allowed = 20;
1640 	int ret = sysctlbyname("kern.total_corpses_allowed",
1641 	    &original_total_corpses_allowed, &original_total_corpses_allowed_sizeof,
1642 	    &total_corpses_allowed, sizeof(total_corpses_allowed));
1643 	T_QUIET; T_EXPECT_POSIX_ZERO(ret, "sysctl kern.total_corpses_allowed");
1644 
1645 	/* set up regular MTE-tagged region */
1646 	kr = mach_vm_allocate(mach_task_self(), &regular_addr, alloc_size,
1647 	    VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
1648 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate regular region");
1649 
1650 	/* set up region for testing INHERIT_NONE */
1651 	kr = mach_vm_allocate(mach_task_self(), &inherit_none_addr, alloc_size,
1652 	    VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
1653 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate INHERIT_NONE region");
1654 
1655 	kr = mach_vm_inherit(mach_task_self(), inherit_none_addr, alloc_size,
1656 	    VM_INHERIT_NONE);
1657 	T_ASSERT_MACH_SUCCESS(kr, "vm_inherit(INHERIT_NONE)");
1658 
1659 	/* set up region for testing "owned" memory */
1660 	kr = mach_vm_allocate(mach_task_self(), &owned_addr, alloc_size,
1661 	    VM_FLAGS_ANYWHERE | VM_FLAGS_MTE | VM_FLAGS_PURGABLE);
1662 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate owned region");
1663 
1664 	int purgable_state = VM_PURGABLE_VOLATILE;
1665 	kr = mach_vm_purgable_control(mach_task_self(), owned_addr, VM_PURGABLE_SET_STATE,
1666 	    &purgable_state);
1667 	T_ASSERT_MACH_SUCCESS(kr, "vm_purgable_control(VM_PURGABLE_VOLATILE)");
1668 	T_SETUPEND;
1669 
1670 	/* Write in some data and tags */
1671 	char *regular_ptr = __arm_mte_increment_tag((char*) regular_addr, 1);
1672 	char *inherit_none_ptr = __arm_mte_increment_tag((char*) inherit_none_addr, 2);
1673 	char *owned_ptr = __arm_mte_increment_tag((char*) owned_addr, 3);
1674 	for (size_t i = 0; i < alloc_size; i++) {
1675 		if (i % MTE_GRANULE_SIZE == 0) {
1676 			__arm_mte_set_tag(&regular_ptr[i]);
1677 			__arm_mte_set_tag(&inherit_none_ptr[i]);
1678 			__arm_mte_set_tag(&owned_ptr[i]);
1679 		}
1680 		regular_ptr[i] = 'a';
1681 		inherit_none_ptr[i] = 'b';
1682 		owned_ptr[i] = 'c';
1683 	}
1684 	T_LOG("wrote data and tags");
1685 
1686 	mach_port_t corpse_port;
1687 	size_t NUM_RETRIES = 5;
1688 	for (size_t i = 0;; i++) {
1689 		kr = task_generate_corpse(mach_task_self(), &corpse_port);
1690 		if (kr == KERN_RESOURCE_SHORTAGE) {
1691 			T_LOG("hit system corpse limit");
1692 			if (i == NUM_RETRIES) {
1693 				T_SKIP("retried too many times, bailing...");
1694 			} else {
1695 				/* give ReportCrash some time to finish handling some corpses */
1696 				sleep(2);
1697 				/* ... then retry */
1698 				T_LOG("retrying... (%lu/%lu)", i + 1, NUM_RETRIES);
1699 				continue;
1700 			}
1701 		}
1702 		T_ASSERT_MACH_SUCCESS(kr, "task_generate_corpse");
1703 		break;
1704 	}
1705 
1706 	/*
1707 	 * Make sure the "regular" region was not shared.
1708 	 * Note: in the case of symmetric CoW, the object IDs may match even if
1709 	 * there is no true sharing happening. However, since we only expect delayed
1710 	 * CoW or eager copies for MTE objects, this isn't a concern here.
1711 	 */
1712 	vm_object_id_t regular_id = get_object_id(mach_task_self(), regular_addr);
1713 	vm_object_id_t regular_corpse_id = get_object_id(corpse_port, regular_addr);
1714 	T_EXPECT_NE(regular_id, regular_corpse_id, "regular region was not shared");
1715 
1716 	/* Make sure the INHERIT_NONE region was shared */
1717 	vm_object_id_t inherit_none_id = get_object_id(mach_task_self(), inherit_none_addr);
1718 	vm_object_id_t inherit_none_corpse_id = get_object_id(corpse_port, inherit_none_addr);
1719 	T_EXPECT_EQ(inherit_none_id, inherit_none_corpse_id, "INHERIT_NONE region was shared");
1720 
1721 	/* Make sure the owned region was shared */
1722 	vm_object_id_t owned_id = get_object_id(mach_task_self(), owned_addr);
1723 	vm_object_id_t owned_corpse_id = get_object_id(corpse_port, owned_addr);
1724 	T_EXPECT_EQ(owned_id, owned_corpse_id, "owned region was shared");
1725 
1726 	/* Cleanup */
1727 	T_SETUPBEGIN;
1728 	kr = mach_vm_deallocate(mach_task_self(), regular_addr, alloc_size);
1729 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "deallocate regular allocation");
1730 	kr = mach_vm_deallocate(mach_task_self(), inherit_none_addr, alloc_size);
1731 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "deallocate INHERIT_NONE allocation");
1732 	kr = mach_vm_deallocate(mach_task_self(), owned_addr, alloc_size);
1733 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "deallocate owned allocation");
1734 	kr = mach_port_deallocate(mach_task_self(), corpse_port);
1735 	T_QUIET; T_ASSERT_MACH_SUCCESS(kr, "deallocate corpse port");
1736 
1737 	/* Reduce the corpse pool size back to its original value */
1738 	ret = sysctlbyname("kern.total_corpses_allowed",
1739 	    NULL, 0,
1740 	    &original_total_corpses_allowed, sizeof(original_total_corpses_allowed));
1741 	T_QUIET; T_EXPECT_POSIX_ZERO(ret, "sysctl kern.total_corpses_allowed");
1742 
1743 	T_SETUPEND;
1744 }
1745 
1746 T_DECL(mte_aio,
1747     "Test MTE asynchronous access faults when the kernel does copyio on behalf of a process",
1748     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1749     XNU_T_META_SOC_SPECIFIC,
1750     T_META_ENABLED(false) /* rdar://154801490 */) {
1751 	const mach_vm_size_t BUF_SIZE = MTE_GRANULE_SIZE;
1752 	uint64_t mask;
1753 
1754 	T_SETUPBEGIN;
1755 	char *buf_untagged = allocate_tagged_memory(BUF_SIZE, &mask);
1756 	char *buf_tagged = __arm_mte_create_random_tag(buf_untagged, mask);
1757 	__arm_mte_set_tag(buf_tagged);
1758 	strncpy(buf_tagged, "ABCDEFG", BUF_SIZE);
1759 
1760 	char *buf_incorrectly_tagged = __arm_mte_increment_tag(buf_tagged, 1);
1761 	int fd = fileno(tmpfile());
1762 
1763 	T_SETUPEND;
1764 
1765 	expect_sigkill(^{
1766 		struct aiocb aiocb = {
1767 		        .aio_fildes = fd,
1768 		        .aio_offset = 0,
1769 		        .aio_buf = buf_incorrectly_tagged,
1770 		        .aio_nbytes = strlen(buf_tagged),
1771 		};
1772 		int ret = aio_write(&aiocb);
1773 		T_ASSERT_POSIX_SUCCESS(ret, "aio_write");
1774 
1775 		/* wait for the kernel to handle our async I/O */
1776 		/* we should be killed at some point while this happens */
1777 		const struct aiocb *aio_list[1] = { &aiocb };
1778 		(void)aio_suspend(aio_list, 1, NULL);
1779 
1780 		/* we were not killed: */
1781 		close(fd);
1782 		T_ASSERT_FAIL("aio write with untagged pointer completed successfully");
1783 	}, "asynchronous I/O write from tagged buffer with incorrect MTE tags");
1784 
1785 	char read_buf[BUF_SIZE];
1786 	ssize_t bytes_read = read(fd, read_buf, sizeof(read_buf));
1787 	T_ASSERT_POSIX_SUCCESS(bytes_read, "read from tmpfile");
1788 
1789 	T_EXPECT_EQ(bytes_read, 0L, "no bytes sent over tmpfile");
1790 
1791 	T_SETUPBEGIN;
1792 	kern_return_t kr = vm_deallocate(mach_task_self(), (vm_address_t) buf_untagged, BUF_SIZE);
1793 	T_ASSERT_MACH_SUCCESS(kr, "deallocate tagged buffer");
1794 
1795 	close(fd);
1796 	T_SETUPEND;
1797 }
1798 
1799 T_HELPER_DECL(mte_tag_violate_aio, "child process to trigger an asynchronous MTE violation via AIO") {
1800 	const mach_vm_size_t BUF_SIZE = MTE_GRANULE_SIZE;
1801 	uint64_t mask;
1802 
1803 	char *buf_untagged = allocate_tagged_memory(BUF_SIZE, &mask);
1804 	char *buf_tagged = __arm_mte_create_random_tag(buf_untagged, mask);
1805 	__arm_mte_set_tag(buf_tagged);
1806 
1807 	strncpy(buf_tagged, "ABCDEFG", BUF_SIZE);
1808 	size_t length = strlen(buf_tagged);
1809 
1810 	char *buf_incorrectly_tagged = __arm_mte_increment_tag(buf_tagged, 1);
1811 	int fd = fileno(tmpfile());
1812 
1813 	struct aiocb aiocb = {
1814 		.aio_fildes = fd,
1815 		.aio_offset = 0,
1816 		.aio_buf = buf_incorrectly_tagged,
1817 		.aio_nbytes = length,
1818 	};
1819 	int ret = aio_write(&aiocb);
1820 	T_ASSERT_POSIX_SUCCESS(ret, "aio_write");
1821 
1822 	/* wait for the kernel to handle our async I/O */
1823 	const struct aiocb *aio_list[1] = { &aiocb };
1824 	ret = aio_suspend(aio_list, 1, NULL);
1825 	T_ASSERT_POSIX_SUCCESS(ret, "aio_suspend");
1826 
1827 	char read_buf[BUF_SIZE];
1828 	ssize_t bytes_read = read(fd, read_buf, sizeof(read_buf));
1829 	T_ASSERT_POSIX_SUCCESS(bytes_read, "read from tmpfile");
1830 
1831 	/* these have to be "may fail" instead of "expect fail" due to rdar://136258500 */
1832 	T_MAYFAIL_WITH_RADAR(136300841);
1833 	T_EXPECT_EQ(bytes_read, (ssize_t)length, "bytes sent over tmpfile");
1834 
1835 	for (size_t i = 0; i < length; i++) {
1836 		T_MAYFAIL_WITH_RADAR(136300841);
1837 		T_EXPECT_EQ(buf_tagged[i], read_buf[i], "character %lu matches", i);
1838 	}
1839 
1840 	kern_return_t kr = vm_deallocate(mach_task_self(), (vm_address_t) buf_untagged, BUF_SIZE);
1841 	T_ASSERT_MACH_SUCCESS(kr, "deallocate tagged buffer");
1842 
1843 	close(fd);
1844 }
1845 
1846 T_DECL(mte_aio_tag_bypass,
1847     "Test nonfatal MTE asynchronous access faults with tag check bypass",
1848     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1849     XNU_T_META_SOC_SPECIFIC) {
1850 	run_helper_with_sec_bypass("mte_tag_violate_aio");
1851 }
1852 #endif /* __arm64__ */
1853 
1854 static void
run_iokit_sysctl_test(int vector)1855 run_iokit_sysctl_test(int vector)
1856 {
1857 	int ret = sysctlbyname("kern.iokittest", NULL, 0, &vector, sizeof(vector));
1858 	T_EXPECT_POSIX_ZERO(ret, "sysctl kern.iokittest(%d)", vector);
1859 }
1860 
1861 T_DECL(mte_iomd_cpu_map,
1862     "Test that IOMemoryDescriptor::map() of userspace memory is mapped as untagged in the kernel",
1863     T_META_ENABLED(TARGET_CPU_ARM64),
1864     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1865     T_META_ASROOT(true),
1866     XNU_T_META_SOC_SPECIFIC)
1867 {
1868 	run_iokit_sysctl_test(333);
1869 }
1870 
1871 T_DECL(mte_iomd_read_write_bytes,
1872     "Test that IOMemoryDescriptor::read/writeBytes() of tagged memory works",
1873     T_META_ENABLED(TARGET_CPU_ARM64),
1874     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1875     T_META_ASROOT(true),
1876     XNU_T_META_SOC_SPECIFIC) {
1877 	run_iokit_sysctl_test(334);
1878 }
1879 
1880 T_DECL(iomd_read_write_bytes_non_mte,
1881     "Test that IOMemoryDescriptor::read/writeBytes() of untagged memory works",
1882     T_META_ENABLED(TARGET_CPU_ARM64),
1883     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1884     T_META_ASROOT(true),
1885     XNU_T_META_SOC_SPECIFIC) {
1886 	run_iokit_sysctl_test(335);
1887 }
1888 
1889 T_DECL(iomd_read_bytes_with_tcf,
1890     "Test that tag mismatches during IOMemoryDescriptor::readBytes() get detected",
1891     T_META_ENABLED(TARGET_CPU_ARM64),
1892     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1893     T_META_ASROOT(true),
1894     XNU_T_META_SOC_SPECIFIC) {
1895 	/* The iokit test will generate an artificial tag check mismatch midway through the buffer */
1896 	expect_sigkill(^{
1897 		run_iokit_sysctl_test(336);
1898 		T_ASSERT_FAIL("Expected this process to get killed");
1899 	}, "asynchronous TCF in readBytes()");
1900 }
1901 
1902 T_DECL(iomd_write_bytes_with_tcf,
1903     "Test that tag mismatches during IOMemoryDescriptor::writeBytes() continue to work out of the box",
1904     T_META_ENABLED(TARGET_CPU_ARM64),
1905     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1906     T_META_ASROOT(true),
1907     XNU_T_META_SOC_SPECIFIC) {
1908 	/* The iokit test will generate an artificial tag check mismatch midway through the buffer */
1909 	expect_sigkill(^{
1910 		run_iokit_sysctl_test(337);
1911 		T_ASSERT_FAIL("Expected this process to get killed");
1912 	}, "asynchronous TCF in writeBytes()");
1913 }
1914 
1915 T_DECL(iomd_create_alias_mapping_in_this_map,
1916     "Test that IOMemoryDescriptor::createMappingInTask() of tagged memory in the current task works",
1917     T_META_ENABLED(TARGET_CPU_ARM64),
1918     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1919     T_META_ASROOT(true),
1920     XNU_T_META_SOC_SPECIFIC) {
1921 	run_iokit_sysctl_test(340);
1922 }
1923 
1924 T_DECL(iomd_create_alias_mapping_in_kernel_map,
1925     "Test that IOMemoryDescriptor::createMappingInTask() of tagged memory in the kernel is allowed",
1926     T_META_ENABLED(TARGET_CPU_ARM64),
1927     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1928     T_META_ASROOT(true),
1929     XNU_T_META_SOC_SPECIFIC) {
1930 	run_iokit_sysctl_test(342);
1931 }
1932 
1933 T_DECL(mte_cpu_map_pageout,
1934     "Test correct behavior of kernel CPU mapping after userspace mapping is paged out",
1935     T_META_ENABLED(TARGET_CPU_ARM64),
1936     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1937     T_META_ASROOT(true),
1938     XNU_T_META_SOC_SPECIFIC)
1939 {
1940 	mach_vm_size_t alloc_size = PAGE_SIZE;
1941 	char *ptr = (char*)(allocate_and_tag_range(alloc_size, TAG_RANDOM_EXCLUDE(0xF)));
1942 	char value = 'A';
1943 	memset(ptr, value, alloc_size);
1944 
1945 	struct {
1946 		mach_vm_size_t size;
1947 		char *ptr;
1948 		char value;
1949 	} args = { alloc_size, ptr, value };
1950 	run_sysctl_test("vm_cpu_map_pageout", (int64_t)(&args));
1951 }
1952 
1953 T_DECL(vm_region_recurse_mte_info,
1954     "Ensure metadata returned by vm_region_recurse correct reflects MTE status",
1955     T_META_ENABLED(TARGET_CPU_ARM64),
1956     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
1957     XNU_T_META_SOC_SPECIFIC,
1958     T_META_ASROOT(true))
1959 {
1960 	T_SETUPBEGIN;
1961 
1962 	/* Given an MTE-enabled region */
1963 	const mach_vm_size_t alloc_size = PAGE_SIZE;
1964 	vm_address_t tagged_buffer_addr = allocate_and_tag_range(alloc_size, 0xa);
1965 	vm_address_t untagged_handle_to_tagged_address = tagged_buffer_addr & ~MTE_TAG_MASK;
1966 
1967 	/* And a non-MTE-enabled region */
1968 	/* (Manually select an address to be sure we're placed in a new region from the tagged region) */
1969 	mach_vm_address_t untagged_buffer_addr = untagged_handle_to_tagged_address + (32 * 1024);
1970 	kern_return_t kr = mach_vm_allocate(
1971 		mach_task_self(),
1972 		&untagged_buffer_addr,
1973 		alloc_size,
1974 		VM_FLAGS_FIXED );
1975 	T_ASSERT_MACH_SUCCESS(kr, "Allocated untagged page");
1976 	/* (And write to it to be sure we populate a VM object) */
1977 	memset((uint8_t*)untagged_buffer_addr, 0, alloc_size);
1978 
1979 	T_SETUPEND;
1980 
1981 	/* When we query the attributes of the region covering the MTE-enabled buffer */
1982 	mach_vm_address_t addr = untagged_handle_to_tagged_address;
1983 	mach_vm_size_t addr_size = alloc_size;
1984 	uint32_t nesting_depth = UINT_MAX;
1985 	mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_V2_COUNT_64;
1986 	vm_region_submap_info_data_64_t region_info;
1987 	kr = vm_region_recurse_64(mach_task_self(), (vm_address_t*)&addr, (vm_size_t*)&addr_size, &nesting_depth, (vm_region_recurse_info_t)&region_info, &count);
1988 
1989 	/* Then our metadata confirms that the region contains an MTE-mappable object */
1990 	T_ASSERT_MACH_SUCCESS(kr, "Query MTE-enabled region");
1991 	T_ASSERT_TRUE(region_info.flags & VM_REGION_FLAG_MTE_ENABLED, "Expected metadata to reflect an MTE mappable object");
1992 
1993 	/* And when we query the same thing via the 'short' info */
1994 	addr = untagged_handle_to_tagged_address;
1995 	addr_size = alloc_size;
1996 	nesting_depth = UINT_MAX;
1997 	count = VM_REGION_SUBMAP_SHORT_INFO_COUNT_64;
1998 	vm_region_submap_short_info_data_64_t short_info;
1999 	kr = mach_vm_region_recurse(mach_task_self(), (mach_vm_address_t*)&addr, (mach_vm_size_t*)&addr_size, &nesting_depth, (vm_region_info_t)&short_info, &count);
2000 
2001 	/* Then the short metadata also confirms that the region contains an MTE-mappable object */
2002 	T_ASSERT_MACH_SUCCESS(kr, "Query MTE-enabled region");
2003 	T_ASSERT_TRUE(short_info.flags & VM_REGION_FLAG_MTE_ENABLED, "Expected metadata to reflect an MTE mappable object");
2004 
2005 	/* And when we query the attributes of the region covering the non-MTE-enabled buffer */
2006 	addr = untagged_buffer_addr;
2007 	addr_size = alloc_size;
2008 	nesting_depth = UINT_MAX;
2009 	count = VM_REGION_SUBMAP_INFO_V2_COUNT_64;
2010 	memset(&region_info, 0, sizeof(region_info));
2011 	kr = mach_vm_region_recurse(mach_task_self(), (mach_vm_address_t*)&addr, (mach_vm_size_t*)&addr_size, &nesting_depth, (vm_region_info_t)&region_info, &count);
2012 
2013 	/* Then our metadata confirm that the region does not contain an MTE-mappable object */
2014 	T_ASSERT_MACH_SUCCESS(kr, "Query MTE-disabled region");
2015 	T_ASSERT_FALSE(region_info.flags & VM_REGION_FLAG_MTE_ENABLED, "Expected metadata to reflect no MTE mappable object");
2016 
2017 	/* And when we query the same thing via the 'short' info */
2018 	addr = untagged_buffer_addr;
2019 	addr_size = alloc_size;
2020 	nesting_depth = UINT_MAX;
2021 	count = VM_REGION_SUBMAP_SHORT_INFO_COUNT_64;
2022 	memset(&short_info, 0, sizeof(short_info));
2023 	kr = mach_vm_region_recurse(mach_task_self(), (mach_vm_address_t*)&addr, (mach_vm_size_t*)&addr_size, &nesting_depth, (vm_region_info_t)&short_info, &count);
2024 
2025 	/* Then the short metadata also confirms that the region does not contain an MTE-mappable object */
2026 	T_ASSERT_MACH_SUCCESS(kr, "Query MTE-disabled region");
2027 	T_ASSERT_FALSE(short_info.flags & VM_REGION_FLAG_MTE_ENABLED, "Expected metadata to reflect no MTE mappable object");
2028 
2029 	/* Cleanup */
2030 	kr = mach_vm_deallocate(mach_task_self(), untagged_handle_to_tagged_address, alloc_size);
2031 	T_ASSERT_MACH_SUCCESS(kr, "deallocate tagged memory");
2032 	kr = mach_vm_deallocate(mach_task_self(), untagged_buffer_addr, alloc_size);
2033 	T_ASSERT_MACH_SUCCESS(kr, "deallocate untagged memory");
2034 }
2035 
2036 T_DECL(mach_vm_read_of_remote_proc,
2037     "Verify that mach_vm_read of a remote MTE-enabled process works",
2038     T_META_ENABLED(TARGET_CPU_ARM64),
2039     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
2040     XNU_T_META_SOC_SPECIFIC,
2041     /* rdar://151142487: gcore won't work on iOS without unrestricting task_read_for_pid */
2042     T_META_BOOTARGS_SET("amfi_unrestrict_task_for_pid=1"),
2043     T_META_ASROOT(true))
2044 {
2045 	/* Given a process that is launched as MTE-enabled */
2046 	char* sleep_args[] = { "/bin/sleep", "5000", NULL};
2047 	posix_spawnattr_t attr;
2048 	errno_t ret = posix_spawnattr_init(&attr);
2049 	T_ASSERT_POSIX_ZERO(ret, "posix_spawnattr_init");
2050 	ret = posix_spawnattr_set_use_sec_transition_shims_np(&attr, POSIX_SPAWN_SECFLAG_EXPLICIT_ENABLE);
2051 	T_ASSERT_POSIX_ZERO(ret, "posix_spawnattr_set_use_sec_transition_shims_np");
2052 	pid_t child_pid = 0;
2053 	ret = posix_spawn(&child_pid, sleep_args[0], NULL, &attr, sleep_args, NULL);
2054 	T_ASSERT_POSIX_ZERO(ret, "posix_spawn");
2055 	T_ASSERT_NE(child_pid, 0, "posix_spawn");
2056 	ret = posix_spawnattr_destroy(&attr);
2057 	T_ASSERT_POSIX_ZERO(ret, "posix_spawnattr_destroy");
2058 
2059 	/* And it's MTE-enabled as expected */
2060 	validate_proc_pidinfo_mte_status(child_pid, true);
2061 
2062 	/* And gcore attempts to mach_vm_read some of its memory */
2063 	char pid_buf[64];
2064 	snprintf(pid_buf, sizeof(pid_buf), "%d", child_pid);
2065 	char* gcore_args[] = { "/usr/bin/gcore", pid_buf, NULL};
2066 	/* Then gcore (and its implicit mach_vm_read()) succeeds */
2067 	posix_spawn_with_flags_and_assert_successful_exit(gcore_args, POSIX_SPAWN_SECFLAG_EXPLICIT_DISABLE, false, false);
2068 
2069 	kill_child(child_pid);
2070 }
2071 
2072 void
do_local_vm_copyin_with_invalid_tag_test(vm_size_t size)2073 do_local_vm_copyin_with_invalid_tag_test(vm_size_t size)
2074 {
2075 	T_SETUPBEGIN;
2076 
2077 	/* Given an MTE-enabled region */
2078 	vm_address_t mte_region = 0;
2079 	kern_return_t kr = vm_allocate(mach_task_self(), &mte_region, size, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
2080 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(MTE)");
2081 	memset((void *)mte_region, 0, size);
2082 
2083 	/* And an MTE-disabled region */
2084 	vm_address_t non_mte_region = 0;
2085 	kr = vm_allocate(mach_task_self(), &non_mte_region, size, VM_FLAGS_ANYWHERE);
2086 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(non-MTE)");
2087 
2088 	/* And the MTE region has tag 0x4, but our pointer is incorrectly tagged 0x5 */
2089 	mte_region |= 0x0400000000000000;
2090 	__arm_mte_set_tag((void *)mte_region);
2091 	mte_region |= 0x0500000000000000;
2092 
2093 	T_SETUPEND;
2094 
2095 	/* When we use `vm_read_overwrite` */
2096 	/* Then the system terminates us due to our incorrectly tagged request */
2097 	vm_size_t out_size;
2098 	vm_read_overwrite(mach_task_self(), mte_region, size, non_mte_region, &out_size);
2099 	T_FAIL("Expected to be SIGKILLED");
2100 }
2101 
2102 T_DECL(local_vm_copyin_with_invalid_tag,
2103     "Verify that copyin of local memory with an invalid tag is denied",
2104     T_META_ENABLED(TARGET_CPU_ARM64),
2105     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
2106     XNU_T_META_SOC_SPECIFIC,
2107     T_META_ASROOT(true))
2108 {
2109 	/*
2110 	 * We go down different code paths depending on the size,
2111 	 * so test both and ensure they're handled consistently.
2112 	 */
2113 	expect_sigkill(^{
2114 		do_local_vm_copyin_with_invalid_tag_test(PAGE_SIZE);
2115 	}, "local_vm_copyin(PAGE_SIZE)");
2116 	expect_sigkill(^{
2117 		do_local_vm_copyin_with_invalid_tag_test(PAGE_SIZE * 10);
2118 	}, "local_vm_copyin(PAGE_SIZE * 10)");
2119 }
2120 
2121 T_DECL(local_vm_copyin_with_large_non_mte_object_with_adjacent_mte_object,
2122     "Ensure a large copyin with a non-MTE object and adjacent MTE object fails",
2123     T_META_ENABLED(TARGET_CPU_ARM64),
2124     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
2125     XNU_T_META_SOC_SPECIFIC,
2126     T_META_ASROOT(true))
2127 {
2128 	expect_sigkill(^{
2129 		/* Given a non-MTE-enabled object */
2130 		vm_address_t non_mte_object_address = 0;
2131 		vm_size_t non_mte_object_size = PAGE_SIZE;
2132 		kern_return_t kr = vm_allocate(mach_task_self(), &non_mte_object_address, non_mte_object_size, VM_FLAGS_ANYWHERE);
2133 		T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(non-MTE)");
2134 		/* And ensure it's present */
2135 		memset((void *)non_mte_object_address, 0, non_mte_object_size);
2136 
2137 		/* And an adjacent MTE object (which is large enough that the total region will definitely be above `msg_ool_size_small`) */
2138 		vm_address_t mte_object_address = non_mte_object_address + non_mte_object_size;
2139 		vm_size_t mte_object_size = PAGE_SIZE * 2;
2140 		kr = vm_allocate(mach_task_self(), &mte_object_address, mte_object_size, VM_FLAGS_FIXED | VM_FLAGS_MTE);
2141 		if (kr == KERN_NO_SPACE) {
2142 		        /*
2143 		         * Skip gracefully if we fail to grab the VA space we need.
2144 		         * Note that we send ourselves a SIGKILL so the expect_sigkill() wrapper
2145 		         * is happy. We can't use T_SKIP or the like because that would elide the
2146 		         * SIGKILL.
2147 		         */
2148 		        T_LOG("Cannot grab required VA space, skipping...");
2149 		        kill(getpid(), SIGKILL);
2150 		        return;
2151 		}
2152 		T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(adjacent MTE)");
2153 		/* And ensure it's present */
2154 		memset((void *)mte_object_address, 0, mte_object_size);
2155 		/* And the MTE object has a non-zero tag (so we TCF when crossing it) */
2156 		mte_object_address |= 0x0400000000000000;
2157 		for (mach_vm_size_t offset = 0; offset < mte_object_size; offset += MTE_GRANULE_SIZE) {
2158 		        __arm_mte_set_tag(&((uint8_t*)mte_object_address)[offset]);
2159 		}
2160 
2161 		/* When we try to copyin the entire region, spanning both objects */
2162 		vm_size_t total_region_size = mte_object_size + non_mte_object_size;
2163 		vm_address_t region_to_overwrite = 0;
2164 		kr = vm_allocate(mach_task_self(), &region_to_overwrite, total_region_size, VM_FLAGS_ANYWHERE);
2165 		T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(scribble region)");
2166 
2167 		vm_size_t out_size;
2168 		/* Then we take a TCF during the copyin */
2169 		vm_read_overwrite(mach_task_self(), non_mte_object_address, total_region_size, region_to_overwrite, &out_size);
2170 	}, "Trigger a TCF during copyin");
2171 }
2172 
2173 T_DECL(local_vm_copyin_with_large_mte_object_with_invalid_size,
2174     "Ensure a large copyin with a non-MTE object but an invalid size fails",
2175     T_META_ENABLED(TARGET_CPU_ARM64),
2176     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
2177     XNU_T_META_SOC_SPECIFIC,
2178     T_META_ASROOT(true))
2179 {
2180 	/* Given an MTE-enabled object (which is large enough that it exceeds `msg_ool_size_small`) */
2181 	vm_address_t mte_object_address = 0;
2182 	vm_size_t mte_object_size = PAGE_SIZE * 3;
2183 	kern_return_t kr = vm_allocate(mach_task_self(), &mte_object_address, mte_object_size, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
2184 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(MTE)");
2185 	/* And ensure it's present */
2186 	memset((void *)mte_object_address, 0, mte_object_size);
2187 
2188 	/* When we try to copyin the region, but specify a size that's too large */
2189 	/* And we ensure this object is not coalesced with the above object */
2190 	vm_size_t invalid_size = mte_object_size + PAGE_SIZE * 16;
2191 	vm_address_t region_to_overwrite = mte_object_address + (PAGE_SIZE * 8);
2192 	kr = vm_allocate(mach_task_self(), &region_to_overwrite, invalid_size, VM_FLAGS_FIXED);
2193 	if (kr == KERN_NO_SPACE) {
2194 		/* Skip gracefully if we fail to grab the VA space we need */
2195 		T_SKIP("Cannot grab required VA space, skipping...");
2196 		return;
2197 	}
2198 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(scribble region)");
2199 
2200 	vm_size_t out_size;
2201 	kr = vm_read_overwrite(mach_task_self(), mte_object_address, invalid_size, region_to_overwrite, &out_size);
2202 	/* Then it fails */
2203 	T_ASSERT_MACH_ERROR(kr, KERN_INVALID_ADDRESS, "copyin fails");
2204 }
2205 
2206 T_DECL(local_vm_copyin_with_large_mte_object_with_hole_in_region,
2207     "Ensure a large copyin with an MTE object, but with a hole in the middle, is rejected",
2208     T_META_ENABLED(TARGET_CPU_ARM64),
2209     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
2210     XNU_T_META_SOC_SPECIFIC,
2211     T_META_ASROOT(true))
2212 {
2213 	/* Given an MTE-enabled object (which is large enough that it exceeds `msg_ool_size_small`) */
2214 	vm_address_t mte_object_address = 0;
2215 	vm_size_t mte_object_size = PAGE_SIZE * 3;
2216 	kern_return_t kr = vm_allocate(mach_task_self(), &mte_object_address, mte_object_size, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
2217 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(MTE)");
2218 	/* And ensure it's present */
2219 	memset((void *)mte_object_address, 0, mte_object_size);
2220 
2221 	/* And a nearby non-MTE object, but we leave a hole in the middle */
2222 	vm_size_t padding = PAGE_SIZE;
2223 	vm_address_t non_mte_object_address = mte_object_address + mte_object_size + padding;
2224 	vm_size_t non_mte_object_size = PAGE_SIZE;
2225 	kr = vm_allocate(mach_task_self(), &non_mte_object_address, non_mte_object_size, VM_FLAGS_FIXED);
2226 	if (kr == KERN_NO_SPACE) {
2227 		/* Skip gracefully if we fail to grab the VA space we need */
2228 		T_SKIP("Cannot grab required VA space, skipping...");
2229 		return;
2230 	}
2231 
2232 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(nearby non-MTE)");
2233 	/* And ensure it's present */
2234 	memset((void *)non_mte_object_address, 0, non_mte_object_size);
2235 
2236 	/* When we try to copyin the whole region, including the hole */
2237 	vm_size_t region_size = mte_object_size + padding + non_mte_object_size;
2238 	vm_address_t region_to_overwrite = 0;
2239 	kr = vm_allocate(mach_task_self(), &region_to_overwrite, region_size, VM_FLAGS_ANYWHERE);
2240 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(scribble region)");
2241 
2242 	vm_size_t out_size;
2243 	kr = vm_read_overwrite(mach_task_self(), mte_object_address, region_size, region_to_overwrite, &out_size);
2244 	/* Then it fails */
2245 	T_ASSERT_MACH_ERROR(kr, KERN_INVALID_ADDRESS, "copyin fails");
2246 }
2247 
2248 T_DECL(local_vm_copyin_with_large_mte_object_with_adjacent_large_mte_object_same_tags,
2249     "Ensure a large copyin with two MTE objects with the same tag succeeds",
2250     T_META_ENABLED(TARGET_CPU_ARM64),
2251     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
2252     XNU_T_META_SOC_SPECIFIC,
2253     T_META_ASROOT(true))
2254 {
2255 	/* Given an MTE-enabled object */
2256 	vm_address_t mte_object1_address = 0;
2257 	vm_size_t mte_object1_size = PAGE_SIZE;
2258 	kern_return_t kr = vm_allocate(mach_task_self(), &mte_object1_address, mte_object1_size, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
2259 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(MTE)");
2260 	/* And ensure it's present */
2261 	memset((void *)mte_object1_address, 0, mte_object1_size);
2262 
2263 	/* And an adjacent MTE object (which is large enough that the total region will definitely be above `msg_ool_size_small`) */
2264 	vm_address_t mte_object2_address = mte_object1_address + mte_object1_size;
2265 	vm_size_t mte_object2_size = PAGE_SIZE * 2;
2266 	kr = vm_allocate(mach_task_self(), &mte_object2_address, mte_object2_size, VM_FLAGS_FIXED | VM_FLAGS_MTE);
2267 	if (kr == KERN_NO_SPACE) {
2268 		/* Skip gracefully if we fail to grab the VA space we need */
2269 		T_SKIP("Cannot grab required VA space, skipping...");
2270 		return;
2271 	}
2272 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(MTE)");
2273 	/* And ensure it's present */
2274 	memset((void *)mte_object2_address, 0, mte_object2_size);
2275 
2276 	/* And both objects share the same tag */
2277 	vm_size_t total_region_size = mte_object1_size + mte_object2_size;
2278 	mte_object1_address |= 0x0400000000000000;
2279 	for (mach_vm_size_t offset = 0; offset < total_region_size; offset += MTE_GRANULE_SIZE) {
2280 		__arm_mte_set_tag(&((uint8_t*)mte_object1_address)[offset]);
2281 	}
2282 
2283 	/* When we try to copyin the entire region, spanning both objects */
2284 	vm_address_t region_to_overwrite = 0;
2285 	kr = vm_allocate(mach_task_self(), &region_to_overwrite, total_region_size, VM_FLAGS_ANYWHERE);
2286 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(scribble region)");
2287 
2288 	vm_size_t out_size;
2289 	kr = vm_read_overwrite(mach_task_self(), mte_object1_address, total_region_size, region_to_overwrite, &out_size);
2290 	/* Then it succeeds */
2291 	T_ASSERT_MACH_SUCCESS(kr, "copyin");
2292 }
2293 
2294 T_DECL(local_vm_copyin_with_large_mte_object_with_adjacent_large_mte_object_different_tags,
2295     "Ensure a large copyin with two MTE objects with a different tag in the second object fails",
2296     T_META_ENABLED(TARGET_CPU_ARM64),
2297     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
2298     XNU_T_META_SOC_SPECIFIC,
2299     T_META_ASROOT(true))
2300 {
2301 	expect_sigkill(^{
2302 		/* Given an MTE-enabled object */
2303 		vm_address_t mte_object1_address = 0;
2304 		vm_size_t mte_object1_size = PAGE_SIZE;
2305 		kern_return_t kr = vm_allocate(mach_task_self(), &mte_object1_address, mte_object1_size, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
2306 		T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(MTE)");
2307 		/* And ensure it's present */
2308 		memset((void *)mte_object1_address, 0, mte_object1_size);
2309 
2310 		/* And an adjacent MTE object (which is large enough that the total region will definitely be above `msg_ool_size_small`) */
2311 		vm_address_t mte_object2_address = mte_object1_address + mte_object1_size;
2312 		vm_size_t mte_object2_size = PAGE_SIZE * 2;
2313 		kr = vm_allocate(mach_task_self(), &mte_object2_address, mte_object2_size, VM_FLAGS_FIXED | VM_FLAGS_MTE);
2314 		if (kr == KERN_NO_SPACE) {
2315 		        /*
2316 		         * Skip gracefully if we fail to grab the VA space we need.
2317 		         * Note that we send ourselves a SIGKILL so the expect_sigkill() wrapper
2318 		         * is happy. We can't use T_SKIP or the like because that would elide the
2319 		         * SIGKILL.
2320 		         */
2321 		        T_LOG("Cannot grab required VA space, skipping...");
2322 		        kill(getpid(), SIGKILL);
2323 		        return;
2324 		}
2325 		T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(adjacent MTE)");
2326 		/* And ensure it's present */
2327 		memset((void *)mte_object2_address, 0, mte_object2_size);
2328 
2329 		/* And the objects have different tags */
2330 		mte_object1_address |= 0x0400000000000000;
2331 		for (mach_vm_size_t offset = 0; offset < mte_object1_size; offset += MTE_GRANULE_SIZE) {
2332 		        __arm_mte_set_tag(&((uint8_t*)mte_object1_address)[offset]);
2333 		}
2334 		mte_object2_address |= 0x0500000000000000;
2335 		for (mach_vm_size_t offset = 0; offset < mte_object2_size; offset += MTE_GRANULE_SIZE) {
2336 		        __arm_mte_set_tag(&((uint8_t*)mte_object2_address)[offset]);
2337 		}
2338 
2339 		/* When we try to copyin the entire region, spanning both objects */
2340 		vm_address_t region_to_overwrite = 0;
2341 		vm_size_t total_region_size = mte_object1_size + mte_object2_size;
2342 		kr = vm_allocate(mach_task_self(), &region_to_overwrite, total_region_size, VM_FLAGS_ANYWHERE);
2343 		T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(scribble region)");
2344 
2345 		/* And we use a pointer that only has a valid tag for the first object */
2346 		/* Then we get a SIGKILL (because we take a TCF) */
2347 		vm_size_t out_size;
2348 		vm_read_overwrite(mach_task_self(), mte_object1_address, total_region_size, region_to_overwrite, &out_size);
2349 	}, "Trigger a TCF during copyin");
2350 }
2351 
2352 T_DECL(local_vm_copyin_with_large_mte_object_with_adjacent_non_mte_object,
2353     "Ensure a large copyin with an MTE object and adjacent non-MTE object fails",
2354     T_META_ENABLED(TARGET_CPU_ARM64),
2355     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
2356     XNU_T_META_SOC_SPECIFIC,
2357     T_META_ASROOT(true))
2358 {
2359 	expect_sigkill(^{
2360 		/* Given an MTE-enabled object */
2361 		vm_address_t mte_object_address = 0;
2362 		vm_size_t mte_object_size = PAGE_SIZE;
2363 		kern_return_t kr = vm_allocate(mach_task_self(), &mte_object_address, mte_object_size, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
2364 		T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(MTE)");
2365 		/* And ensure it's present */
2366 		memset((void *)mte_object_address, 0, mte_object_size);
2367 		/* And the MTE object has a non-zero tag (so we CTCF when crossing to an untagged region) */
2368 		vm_address_t tagged_mte_object_address = mte_object_address | 0x0400000000000000;
2369 		for (mach_vm_size_t offset = 0; offset < mte_object_size; offset += MTE_GRANULE_SIZE) {
2370 		        __arm_mte_set_tag(&((uint8_t*)tagged_mte_object_address)[offset]);
2371 		}
2372 
2373 		/* And an adjacent non-MTE object (which is large enough that the total region will definitely be above `msg_ool_size_small`) */
2374 		vm_address_t non_mte_object_address = mte_object_address + mte_object_size;
2375 		vm_size_t non_mte_object_size = PAGE_SIZE * 2;
2376 		kr = vm_allocate(mach_task_self(), &non_mte_object_address, non_mte_object_size, VM_FLAGS_FIXED);
2377 		if (kr == KERN_NO_SPACE) {
2378 		        /*
2379 		         * Skip gracefully if we fail to grab the VA space we need.
2380 		         * Note that we send ourselves a SIGKILL so the expect_sigkill() wrapper
2381 		         * is happy. We can't use T_SKIP or the like because that would elide the
2382 		         * SIGKILL.
2383 		         */
2384 		        T_LOG("Cannot grab required VA space, skipping...");
2385 		        kill(getpid(), SIGKILL);
2386 		        return;
2387 		}
2388 		T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(adjacent non-MTE)");
2389 		/* And ensure it's present */
2390 		memset((void *)non_mte_object_address, 0, non_mte_object_size);
2391 
2392 		/* When we try to copyin the entire region, spanning both objects */
2393 		vm_size_t total_region_size = mte_object_size + non_mte_object_size;
2394 		vm_address_t region_to_overwrite = 0;
2395 		kr = vm_allocate(mach_task_self(), &region_to_overwrite, total_region_size, VM_FLAGS_ANYWHERE);
2396 		T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(scribble region)");
2397 
2398 		vm_size_t out_size;
2399 		vm_read_overwrite(mach_task_self(), mte_object_address, total_region_size, region_to_overwrite, &out_size);
2400 		/* Then we're killed due to a CTCF */
2401 	}, "Trigger a CTCF during copyin");
2402 }
2403 
2404 T_DECL(make_memory_entry_handles_kernel_buffers,
2405     "Ensure mach_make_memory_entry does not panic when handed an MTE copy",
2406     T_META_ENABLED(TARGET_CPU_ARM64),
2407     T_META_REQUIRES_SYSCTL_EQ("hw.optional.arm.FEAT_MTE2", 1),
2408     XNU_T_META_SOC_SPECIFIC,
2409     T_META_ASROOT(true))
2410 {
2411 	/* Given an MTE-enabled object */
2412 	vm_address_t mte_object_address = 0;
2413 	vm_size_t mte_object_size = PAGE_SIZE;
2414 	kern_return_t kr = vm_allocate(mach_task_self(), &mte_object_address, mte_object_size, VM_FLAGS_ANYWHERE | VM_FLAGS_MTE);
2415 	T_ASSERT_MACH_SUCCESS(kr, "vm_allocate(MTE)");
2416 	/* And ensure it's present */
2417 	memset((void *)mte_object_address, 0, mte_object_size);
2418 	/* And assign a non-zero tag just for authenticity */
2419 	vm_address_t tagged_mte_object_address = mte_object_address | 0x0400000000000000;
2420 	for (mach_vm_size_t offset = 0; offset < mte_object_size; offset += MTE_GRANULE_SIZE) {
2421 		__arm_mte_set_tag(&((uint8_t*)tagged_mte_object_address)[offset]);
2422 	}
2423 
2424 	/* When I use mach_make_memory_entry_64(MAP_MEM_VM_COPY) */
2425 	mach_vm_size_t size = mte_object_size;
2426 	mach_port_t memory_entry_port;
2427 	kr = mach_make_memory_entry_64(mach_task_self(),
2428 	    &size,
2429 	    tagged_mte_object_address,
2430 	    VM_PROT_DEFAULT | MAP_MEM_VM_COPY | MAP_MEM_USE_DATA_ADDR,
2431 	    &memory_entry_port, MEMORY_OBJECT_NULL);
2432 	/* Then the system does not panic... */
2433 	T_ASSERT_MACH_SUCCESS(kr, "mach_make_memory_entry_64(MTE object)");
2434 }
2435