31  *  object with static storage duration other than by assigning a value to an
39  * anything with it in order to trigger a read page fault. We therefore must use
138  * return value indicates whether the read/write succeeds without a fatal
147 	/* If a fatal signal arose, we will jump back here and failed is set. */  in try_access_buf()
161 /* Try and read from a buffer, return true if no fatal signal. */
167 /* Try and write to a buffer, return true if no fatal signal. */
174  * Try and BOTH read from AND write to a buffer, return true if BOTH operations
217 /* Establish a varying pattern in a buffer. */
225 		memset(ptr2, 'a' + (i % 26), page_size);  in set_pattern()
230  * Check that a buffer contains the pattern set by set_pattern(), starting at a
241 		char expected = 'a' + ((offset / page_size) % 26);  in check_pattern_offset()
250 /* Check that a buffer contains the pattern set by set_pattern(). */
256 /* Determine if a buffer contains only repetitions of a specified char. */
305 	const unsigned long NUM_PAGES = 10;  in TEST_F()
329 	/* Establish a guard page at the end of the mapping. */  in TEST_F()
351 	 *  Test setting a _range_ of pages, namely the first 3. The first of  in TEST_F()
403 	/* Reserve a 100 page region over which we can install VMAs. */  in TEST_F()
408 	/* Place a VMA of 10 pages size at the start of the region. */  in TEST_F()
409 	ptr1 = mmap_(self, variant, ptr_region, 10 * page_size,  in TEST_F()
413 	/* Place a VMA of 5 pages size 50 pages into the region. */  in TEST_F()
418 	/* Place a VMA of 20 pages size at the end of the region. */  in TEST_F()
424 	ASSERT_EQ(munmap(&ptr_region[10 * page_size], 40 * page_size), 0);  in TEST_F()
430 	 * 0    10 .. 50   55 .. 80   100  in TEST_F()
448 	for (i = 0; i < 10; i++) {  in TEST_F()
471 	for (i = 0; i < 10; i++) {  in TEST_F()
490 	ptr = mmap_(self, variant, &ptr_region[10 * page_size], 40 * page_size,  in TEST_F()
500 	 * 0    10 .. 50   55 .. 80   100  in TEST_F()
542 	 * 10 pages offset 1 page into reserve region. We MAP_POPULATE so we  in TEST_F()
546 	ptr1 = mmap_(self, variant, &ptr_region[page_size], 10 * page_size,  in TEST_F()
615 	ASSERT_EQ(munmap(ptr1, 10 * page_size), 0);  in TEST_F()
626 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
655 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
665 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
693 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
696 	for (i = 0; i < 10; i++) {  in TEST_F()
703 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
713 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
718 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_INSTALL), 0);  in TEST_F()
721 	for (i = 0; i < 10; i++) {  in TEST_F()
748 	for (i = 9; i < 10; i++) {  in TEST_F()
766 	for (i = 0; i < 10; i++) {  in TEST_F()
775 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_INSTALL), 0);  in TEST_F()
778 	for (i = 0; i < 10; i++) {  in TEST_F()
789 	for (i = 0; i < 10; i++) {  in TEST_F()
801 	for (i = 0; i < 10; i++) {  in TEST_F()
812 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
815 	for (i = 0; i < 10; i++) {  in TEST_F()
827 	for (i = 0; i < 10; i++) {  in TEST_F()
834 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
844 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
849 	for (i = 0; i < 10; i++) {  in TEST_F()
856 	for (i = 0; i < 10; i += 2) {  in TEST_F()
864 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_DONTNEED), 0);  in TEST_F()
867 	for (i = 0; i < 10; i++) {  in TEST_F()
877 				/* If anon, then we get a zero page. */  in TEST_F()
895 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
905 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
910 	for (i = 0; i < 10; i++) {  in TEST_F()
917 	ASSERT_EQ(mlock(ptr, 10 * page_size), 0);  in TEST_F()
920 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_INSTALL), -1);  in TEST_F()
924 	ASSERT_EQ(munlock(ptr, 10 * page_size), 0);  in TEST_F()
930 	for (i = 0; i < 10; i++) {  in TEST_F()
951 	 * pages removed as it is a non-destructive operation.  in TEST_F()
953 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
956 	for (i = 0; i < 10; i++) {  in TEST_F()
963 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
970  * - Moving a mapping alone should retain markers as they are.
990 	/* Map a new region we will move this range into. Doing this ensures  in TEST_F()
991 	 * that we have reserved a range to map into.  in TEST_F()
1016  * same if it were a PROT_NONE mapping).
1023 	/* Map 10 pages... */  in TEST_F()
1024 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1038 	/* Now expand to 10 pages. */  in TEST_F()
1039 	ptr = mremap(ptr, 5 * page_size, 10 * page_size, 0);  in TEST_F()
1048 	/* Reserve a region which we can move to and expand into. */  in TEST_F()
1053 	ptr = mremap(ptr, 10 * page_size, 20 * page_size,  in TEST_F()
1064 	 * A real user would have to remove guard markers, but would reasonably  in TEST_F()
1077  * if the user were using a PROT_NONE mapping they'd have to manually fix this
1114 	 * As with expansion, a real user would have to remove guard pages and  in TEST_F()
1141  * Assert that forking a process with VMAs that do not have VM_WIPEONFORK set
1151 	/* Map 10 pages. */  in TEST_F()
1152 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1165 		for (i = 0; i < 10; i++) {  in TEST_F()
1173 		ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
1184 	for (i = 0; i < 10; i++) {  in TEST_F()
1192 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1209 	/* Map 10 pages. */  in TEST_F()
1210 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1215 	for (i = 0; i < 10 * page_size; i++) {  in TEST_F()
1216 		char chr = 'a' + (i % 26);  in TEST_F()
1227 		for (i = 0; i < 10 * page_size; i++) {  in TEST_F()
1228 			char expected = 'a' + (i % 26);  in TEST_F()
1235 		ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_INSTALL), 0);  in TEST_F()
1237 		ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
1243 		for (i = 0; i < 10 * page_size; i++) {  in TEST_F()
1258 	for (i = 0; i < 10 * page_size; i++) {  in TEST_F()
1259 		char expected = 'a' + (i % 26);  in TEST_F()
1266 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1270  * Assert that forking a process with VMAs that do have VM_WIPEONFORK set
1283 	/* Map 10 pages. */  in TEST_F()
1284 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1289 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_WIPEONFORK), 0);  in TEST_F()
1300 		for (i = 0; i < 10; i++) {  in TEST_F()
1314 	for (i = 0; i < 10; i++) {  in TEST_F()
1322 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1335 	/* Map 10 pages. */  in TEST_F()
1336 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1341 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_INSTALL), 0);  in TEST_F()
1344 	for (i = 0; i < 10; i++) {  in TEST_F()
1351 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_FREE), 0);  in TEST_F()
1354 	for (i = 0; i < 10; i++) {  in TEST_F()
1361 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1370 	/* Map 10 pages. */  in TEST_F()
1371 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1376 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_INSTALL), 0);  in TEST_F()
1379 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_POPULATE_READ), -1);  in TEST_F()
1383 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_POPULATE_WRITE), -1);  in TEST_F()
1387 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1397 	/* Map 10 pages. */  in TEST_F()
1398 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1403 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_INSTALL), 0);  in TEST_F()
1406 	for (i = 0; i < 10; i++) {  in TEST_F()
1413 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_COLD), 0);  in TEST_F()
1416 	for (i = 0; i < 10; i++) {  in TEST_F()
1423 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_PAGEOUT), 0);  in TEST_F()
1426 	for (i = 0; i < 10; i++) {  in TEST_F()
1433 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1461 	/* Map 10 pages. */  in TEST_F()
1462 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1468 	range.len = 10 * page_size;  in TEST_F()
1474 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_INSTALL), 0);  in TEST_F()
1477 	for (i = 0; i < 10; i++) {  in TEST_F()
1486 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1490  * Mark a region within a file-backed mapping using MADV_SEQUENTIAL so we
1506 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1510 	/* Establish a pattern of data in the file. */  in TEST_F()
1511 	set_pattern(ptr, 10, page_size);  in TEST_F()
1512 	ASSERT_TRUE(check_pattern(ptr, 10, page_size));  in TEST_F()
1515 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_SEQUENTIAL), 0);  in TEST_F()
1517 	/* Mark every other page a guard page. */  in TEST_F()
1518 	for (i = 0; i < 10; i += 2) {  in TEST_F()
1525 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_PAGEOUT), 0);  in TEST_F()
1528 	for (i = 0; i < 10; i++) {  in TEST_F()
1536 			ASSERT_EQ(*chrp, 'a' + i);  in TEST_F()
1541 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
1544 	if (!check_pattern(ptr, 10, page_size))  in TEST_F()
1547 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1563 	ptr_shared = mmap_(self, variant, NULL, 10 * page_size, PROT_READ | PROT_WRITE, 0, 0);  in TEST_F()
1567 	ptr_private = mmap(NULL, 10 * page_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, self->fd, 0);  in TEST_F()
1571 	set_pattern(ptr_shared, 10, page_size);  in TEST_F()
1574 	for (i = 0; i < 10; i += 2) {  in TEST_F()
1580 	for (i = 0; i < 10; i++) {  in TEST_F()
1588 	for (i = 0; i < 10; i += 2) {  in TEST_F()
1594 	for (i = 0; i < 10; i++) {  in TEST_F()
1602 	ASSERT_EQ(madvise(ptr_shared, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
1604 	for (i = 0; i < 10; i++) {  in TEST_F()
1612 	ASSERT_EQ(madvise(ptr_private, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
1614 	for (i = 0; i < 10; i++) {  in TEST_F()
1622 	ASSERT_TRUE(check_pattern(ptr_shared, 10, page_size));  in TEST_F()
1623 	ASSERT_TRUE(check_pattern(ptr_private, 10, page_size));  in TEST_F()
1626 	for (i = 0; i < 10; i += 2) {  in TEST_F()
1629 		memset(ptr, 'a' + i, page_size);  in TEST_F()
1651 	for (i = 0; i < 10; i++) {  in TEST_F()
1661 	ASSERT_EQ(madvise(ptr_private, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
1674 	for (i = 0; i < 10; i++) {  in TEST_F()
1688 		/* Everything else is a private mapping. */  in TEST_F()
1689 		ASSERT_TRUE(is_buf_eq(ptr, page_size, 'a' + i));  in TEST_F()
1692 	ASSERT_EQ(munmap(ptr_shared, 10 * page_size), 0);  in TEST_F()
1693 	ASSERT_EQ(munmap(ptr_private, 10 * page_size), 0);  in TEST_F()
1696 /* Test that guard regions established over a read-only mapping function correctly. */
1707 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1710 	set_pattern(ptr, 10, page_size);  in TEST_F()
1711 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1719 	ptr = mmap_(self, variant, NULL, 10 * page_size, PROT_READ, 0, 0);  in TEST_F()
1723 	for (i = 0; i < 10; i += 2) {  in TEST_F()
1730 	for (i = 0; i < 10; i++) {  in TEST_F()
1737 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
1740 	ASSERT_TRUE(check_pattern(ptr, 10, page_size));  in TEST_F()
1742 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1754 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1758 	/* Establish a pattern in the backing file. */  in TEST_F()
1759 	set_pattern(ptr, 10, page_size);  in TEST_F()
1765 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_PAGEOUT), 0);  in TEST_F()
1768 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1769 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1774 	for (i = 0; i < 10; i += 2) {  in TEST_F()
1781 	for (i = 1; i < 10; i += 2) {  in TEST_F()
1788 	for (i = 0; i < 10; i++) {  in TEST_F()
1794 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1806 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1811 	 * Establish a pattern in the backing file, just so there is data  in TEST_F()
1814 	set_pattern(ptr, 10, page_size);  in TEST_F()
1817 	for (i = 0; i < 10; i += 2) {  in TEST_F()
1824 	for (i = 0; i < 10; i++) {  in TEST_F()
1831 	ASSERT_EQ(ftruncate(self->fd, 10 * page_size), 0);  in TEST_F()
1834 	for (i = 0; i < 10; i++) {  in TEST_F()
1842 	ASSERT_EQ(ftruncate(self->fd, 10 * page_size), 0);  in TEST_F()
1845 	for (i = 0; i < 10; i++) {  in TEST_F()
1851 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1864 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
1867 	set_pattern(ptr, 10, page_size);  in TEST_F()
1869 	/* Install a guard region in the middle of the mapping. */  in TEST_F()
1883 	for (i = 0; i < 10; i++) {  in TEST_F()
1894 	for (i = 0; i < 10; i++) {  in TEST_F()
1901 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
1910 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1914  * Ensure that a memfd works correctly with guard regions, that we can write
1927 	/* OK, we need a memfd, so close existing one. */  in TEST_F()
1934 	ASSERT_EQ(ftruncate(self->fd, 10 * page_size), 0);  in TEST_F()
1937 	ptr = mmap_(self, variant, NULL, 10 * page_size, PROT_READ | PROT_WRITE, 0, 0);  in TEST_F()
1939 	set_pattern(ptr, 10, page_size);  in TEST_F()
1940 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1946 	ptr = mmap_(self, variant, NULL, 10 * page_size, PROT_READ, 0, 0);  in TEST_F()
1950 	ASSERT_TRUE(check_pattern(ptr, 10, page_size));  in TEST_F()
1953 	for (i = 0; i < 10; i += 2) {  in TEST_F()
1960 	for (i = 0; i < 10; i++) {  in TEST_F()
1967 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
1970 	ASSERT_TRUE(check_pattern(ptr, 10, page_size));  in TEST_F()
1973 	for (i = 0; i < 10; i++) {  in TEST_F()
1979 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
1986  * use, test that guard regions function with a mapping to the anonymous zero
1998 	/* Obtain a read-only i.e. anon zero page mapping. */  in TEST_F()
1999 	ptr = mmap_(self, variant, NULL, 10 * page_size, PROT_READ, 0, 0);  in TEST_F()
2003 	for (i = 0; i < 10; i += 2) {  in TEST_F()
2010 	for (i = 0; i < 10; i++) {  in TEST_F()
2017 	ASSERT_EQ(madvise(ptr, 10 * page_size, MADV_GUARD_REMOVE), 0);  in TEST_F()
2020 	for (i = 0; i < 10; i++) {  in TEST_F()
2027 	ASSERT_TRUE(is_buf_eq(ptr, 10 * page_size, '\0'));  in TEST_F()
2029 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()
2045 	ptr = mmap_(self, variant, NULL, 10 * page_size,  in TEST_F()
2050 	for (i = 0; i < 10; i++) {  in TEST_F()
2058 	/* Install a guard region in every other page. */  in TEST_F()
2059 	for (i = 0; i < 10; i += 2) {  in TEST_F()
2066 	for (i = 0; i < 10; i++) {  in TEST_F()
2075 	ASSERT_EQ(munmap(ptr, 10 * page_size), 0);  in TEST_F()