1 files changed, 258 insertions, 45 deletions

diff --git a/tools/testing/selftests/mm/mremap_test.c b/tools/testing/selftests/mm/mremap_test.c
index 5c3773de9f..1d4c1589c3 100644
--- a/tools/testing/selftests/mm/mremap_test.c
+++ b/tools/testing/selftests/mm/mremap_test.c
@@ -23,12 +23,15 @@
 #define VALIDATION_NO_THRESHOLD 0	/* Verify the entire region */
 
 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
+#define SIZE_MB(m) ((size_t)m * (1024 * 1024))
+#define SIZE_KB(k) ((size_t)k * 1024)
 
 struct config {
 	unsigned long long src_alignment;
 	unsigned long long dest_alignment;
 	unsigned long long region_size;
 	int overlapping;
+	int dest_preamble_size;
 };
 
 struct test {
@@ -44,6 +47,7 @@ enum {
 	_1MB = 1ULL << 20,
 	_2MB = 2ULL << 20,
 	_4MB = 4ULL << 20,
+	_5MB = 5ULL << 20,
 	_1GB = 1ULL << 30,
 	_2GB = 2ULL << 30,
 	PMD = _2MB,
@@ -146,6 +150,60 @@ static bool is_range_mapped(FILE *maps_fp, void *start, void *end)
 }
 
 /*
+ * Returns the start address of the mapping on success, else returns
+ * NULL on failure.
+ */
+static void *get_source_mapping(struct config c)
+{
+	unsigned long long addr = 0ULL;
+	void *src_addr = NULL;
+	unsigned long long mmap_min_addr;
+
+	mmap_min_addr = get_mmap_min_addr();
+	/*
+	 * For some tests, we need to not have any mappings below the
+	 * source mapping. Add some headroom to mmap_min_addr for this.
+	 */
+	mmap_min_addr += 10 * _4MB;
+
+retry:
+	addr += c.src_alignment;
+	if (addr < mmap_min_addr)
+		goto retry;
+
+	src_addr = mmap((void *) addr, c.region_size, PROT_READ | PROT_WRITE,
+					MAP_FIXED_NOREPLACE | MAP_ANONYMOUS | MAP_SHARED,
+					-1, 0);
+	if (src_addr == MAP_FAILED) {
+		if (errno == EPERM || errno == EEXIST)
+			goto retry;
+		goto error;
+	}
+	/*
+	 * Check that the address is aligned to the specified alignment.
+	 * Addresses which have alignments that are multiples of that
+	 * specified are not considered valid. For instance, 1GB address is
+	 * 2MB-aligned, however it will not be considered valid for a
+	 * requested alignment of 2MB. This is done to reduce coincidental
+	 * alignment in the tests.
+	 */
+	if (((unsigned long long) src_addr & (c.src_alignment - 1)) ||
+			!((unsigned long long) src_addr & c.src_alignment)) {
+		munmap(src_addr, c.region_size);
+		goto retry;
+	}
+
+	if (!src_addr)
+		goto error;
+
+	return src_addr;
+error:
+	ksft_print_msg("Failed to map source region: %s\n",
+			strerror(errno));
+	return NULL;
+}
+
+/*
  * This test validates that merge is called when expanding a mapping.
  * Mapping containing three pages is created, middle page is unmapped
  * and then the mapping containing the first page is expanded so that
@@ -225,59 +283,83 @@ out:
 }
 
 /*
- * Returns the start address of the mapping on success, else returns
- * NULL on failure.
+ * Verify that an mremap within a range does not cause corruption
+ * of unrelated part of range.
+ *
+ * Consider the following range which is 2MB aligned and is
+ * a part of a larger 20MB range which is not shown. Each
+ * character is 256KB below making the source and destination
+ * 2MB each. The lower case letters are moved (s to d) and the
+ * upper case letters are not moved. The below test verifies
+ * that the upper case S letters are not corrupted by the
+ * adjacent mremap.
+ *
+ * |DDDDddddSSSSssss|
  */
-static void *get_source_mapping(struct config c)
+static void mremap_move_within_range(char pattern_seed)
 {
-	unsigned long long addr = 0ULL;
-	void *src_addr = NULL;
-	unsigned long long mmap_min_addr;
+	char *test_name = "mremap mremap move within range";
+	void *src, *dest;
+	int i, success = 1;
+
+	size_t size = SIZE_MB(20);
+	void *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE,
+			 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if (ptr == MAP_FAILED) {
+		perror("mmap");
+		success = 0;
+		goto out;
+	}
+	memset(ptr, 0, size);
 
-	mmap_min_addr = get_mmap_min_addr();
+	src = ptr + SIZE_MB(6);
+	src = (void *)((unsigned long)src & ~(SIZE_MB(2) - 1));
 
-retry:
-	addr += c.src_alignment;
-	if (addr < mmap_min_addr)
-		goto retry;
+	/* Set byte pattern for source block. */
+	srand(pattern_seed);
+	for (i = 0; i < SIZE_MB(2); i++) {
+		((char *)src)[i] = (char) rand();
+	}
 
-	src_addr = mmap((void *) addr, c.region_size, PROT_READ | PROT_WRITE,
-					MAP_FIXED_NOREPLACE | MAP_ANONYMOUS | MAP_SHARED,
-					-1, 0);
-	if (src_addr == MAP_FAILED) {
-		if (errno == EPERM || errno == EEXIST)
-			goto retry;
-		goto error;
+	dest = src - SIZE_MB(2);
+
+	void *new_ptr = mremap(src + SIZE_MB(1), SIZE_MB(1), SIZE_MB(1),
+						   MREMAP_MAYMOVE | MREMAP_FIXED, dest + SIZE_MB(1));
+	if (new_ptr == MAP_FAILED) {
+		perror("mremap");
+		success = 0;
+		goto out;
 	}
-	/*
-	 * Check that the address is aligned to the specified alignment.
-	 * Addresses which have alignments that are multiples of that
-	 * specified are not considered valid. For instance, 1GB address is
-	 * 2MB-aligned, however it will not be considered valid for a
-	 * requested alignment of 2MB. This is done to reduce coincidental
-	 * alignment in the tests.
-	 */
-	if (((unsigned long long) src_addr & (c.src_alignment - 1)) ||
-			!((unsigned long long) src_addr & c.src_alignment)) {
-		munmap(src_addr, c.region_size);
-		goto retry;
+
+	/* Verify byte pattern after remapping */
+	srand(pattern_seed);
+	for (i = 0; i < SIZE_MB(1); i++) {
+		char c = (char) rand();
+
+		if (((char *)src)[i] != c) {
+			ksft_print_msg("Data at src at %d got corrupted due to unrelated mremap\n",
+				       i);
+			ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff,
+					((char *) src)[i] & 0xff);
+			success = 0;
+		}
 	}
 
-	if (!src_addr)
-		goto error;
+out:
+	if (munmap(ptr, size) == -1)
+		perror("munmap");
 
-	return src_addr;
-error:
-	ksft_print_msg("Failed to map source region: %s\n",
-			strerror(errno));
-	return NULL;
+	if (success)
+		ksft_test_result_pass("%s\n", test_name);
+	else
+		ksft_test_result_fail("%s\n", test_name);
 }
 
 /* Returns the time taken for the remap on success else returns -1. */
 static long long remap_region(struct config c, unsigned int threshold_mb,
 			      char pattern_seed)
 {
-	void *addr, *src_addr, *dest_addr;
+	void *addr, *src_addr, *dest_addr, *dest_preamble_addr;
 	unsigned long long i;
 	struct timespec t_start = {0, 0}, t_end = {0, 0};
 	long long  start_ns, end_ns, align_mask, ret, offset;
@@ -294,7 +376,7 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 		goto out;
 	}
 
-	/* Set byte pattern */
+	/* Set byte pattern for source block. */
 	srand(pattern_seed);
 	for (i = 0; i < threshold; i++)
 		memset((char *) src_addr + i, (char) rand(), 1);
@@ -306,6 +388,9 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 	addr = (void *) (((unsigned long long) src_addr + c.region_size
 			  + offset) & align_mask);
 
+	/* Remap after the destination block preamble. */
+	addr += c.dest_preamble_size;
+
 	/* See comment in get_source_mapping() */
 	if (!((unsigned long long) addr & c.dest_alignment))
 		addr = (void *) ((unsigned long long) addr | c.dest_alignment);
@@ -316,11 +401,29 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 		if (addr + c.dest_alignment < addr) {
 			ksft_print_msg("Couldn't find a valid region to remap to\n");
 			ret = -1;
-			goto out;
+			goto clean_up_src;
 		}
 		addr += c.dest_alignment;
 	}
 
+	if (c.dest_preamble_size) {
+		dest_preamble_addr = mmap((void *) addr - c.dest_preamble_size, c.dest_preamble_size,
+					  PROT_READ | PROT_WRITE,
+					  MAP_FIXED_NOREPLACE | MAP_ANONYMOUS | MAP_SHARED,
+							-1, 0);
+		if (dest_preamble_addr == MAP_FAILED) {
+			ksft_print_msg("Failed to map dest preamble region: %s\n",
+					strerror(errno));
+			ret = -1;
+			goto clean_up_src;
+		}
+
+		/* Set byte pattern for the dest preamble block. */
+		srand(pattern_seed);
+		for (i = 0; i < c.dest_preamble_size; i++)
+			memset((char *) dest_preamble_addr + i, (char) rand(), 1);
+	}
+
 	clock_gettime(CLOCK_MONOTONIC, &t_start);
 	dest_addr = mremap(src_addr, c.region_size, c.region_size,
 					  MREMAP_MAYMOVE|MREMAP_FIXED, (char *) addr);
@@ -329,7 +432,7 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 	if (dest_addr == MAP_FAILED) {
 		ksft_print_msg("mremap failed: %s\n", strerror(errno));
 		ret = -1;
-		goto clean_up_src;
+		goto clean_up_dest_preamble;
 	}
 
 	/* Verify byte pattern after remapping */
@@ -338,7 +441,7 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 		char c = (char) rand();
 
 		if (((char *) dest_addr)[i] != c) {
-			ksft_print_msg("Data after remap doesn't match at offset %d\n",
+			ksft_print_msg("Data after remap doesn't match at offset %llu\n",
 				       i);
 			ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff,
 					((char *) dest_addr)[i] & 0xff);
@@ -347,6 +450,23 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
 		}
 	}
 
+	/* Verify the dest preamble byte pattern after remapping */
+	if (c.dest_preamble_size) {
+		srand(pattern_seed);
+		for (i = 0; i < c.dest_preamble_size; i++) {
+			char c = (char) rand();
+
+			if (((char *) dest_preamble_addr)[i] != c) {
+				ksft_print_msg("Preamble data after remap doesn't match at offset %d\n",
+					       i);
+				ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff,
+					       ((char *) dest_preamble_addr)[i] & 0xff);
+				ret = -1;
+				goto clean_up_dest;
+			}
+		}
+	}
+
 	start_ns = t_start.tv_sec * NS_PER_SEC + t_start.tv_nsec;
 	end_ns = t_end.tv_sec * NS_PER_SEC + t_end.tv_nsec;
 	ret = end_ns - start_ns;
@@ -359,12 +479,92 @@ static long long remap_region(struct config c, unsigned int threshold_mb,
  */
 clean_up_dest:
 	munmap(dest_addr, c.region_size);
+clean_up_dest_preamble:
+	if (c.dest_preamble_size && dest_preamble_addr)
+		munmap(dest_preamble_addr, c.dest_preamble_size);
 clean_up_src:
 	munmap(src_addr, c.region_size);
 out:
 	return ret;
 }
 
+/*
+ * Verify that an mremap aligning down does not destroy
+ * the beginning of the mapping just because the aligned
+ * down address landed on a mapping that maybe does not exist.
+ */
+static void mremap_move_1mb_from_start(char pattern_seed)
+{
+	char *test_name = "mremap move 1mb from start at 1MB+256KB aligned src";
+	void *src = NULL, *dest = NULL;
+	int i, success = 1;
+
+	/* Config to reuse get_source_mapping() to do an aligned mmap. */
+	struct config c = {
+		.src_alignment = SIZE_MB(1) + SIZE_KB(256),
+		.region_size = SIZE_MB(6)
+	};
+
+	src = get_source_mapping(c);
+	if (!src) {
+		success = 0;
+		goto out;
+	}
+
+	c.src_alignment = SIZE_MB(1) + SIZE_KB(256);
+	dest = get_source_mapping(c);
+	if (!dest) {
+		success = 0;
+		goto out;
+	}
+
+	/* Set byte pattern for source block. */
+	srand(pattern_seed);
+	for (i = 0; i < SIZE_MB(2); i++) {
+		((char *)src)[i] = (char) rand();
+	}
+
+	/*
+	 * Unmap the beginning of dest so that the aligned address
+	 * falls on no mapping.
+	 */
+	munmap(dest, SIZE_MB(1));
+
+	void *new_ptr = mremap(src + SIZE_MB(1), SIZE_MB(1), SIZE_MB(1),
+						   MREMAP_MAYMOVE | MREMAP_FIXED, dest + SIZE_MB(1));
+	if (new_ptr == MAP_FAILED) {
+		perror("mremap");
+		success = 0;
+		goto out;
+	}
+
+	/* Verify byte pattern after remapping */
+	srand(pattern_seed);
+	for (i = 0; i < SIZE_MB(1); i++) {
+		char c = (char) rand();
+
+		if (((char *)src)[i] != c) {
+			ksft_print_msg("Data at src at %d got corrupted due to unrelated mremap\n",
+				       i);
+			ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff,
+					((char *) src)[i] & 0xff);
+			success = 0;
+		}
+	}
+
+out:
+	if (src && munmap(src, c.region_size) == -1)
+		perror("munmap src");
+
+	if (dest && munmap(dest, c.region_size) == -1)
+		perror("munmap dest");
+
+	if (success)
+		ksft_test_result_pass("%s\n", test_name);
+	else
+		ksft_test_result_fail("%s\n", test_name);
+}
+
 static void run_mremap_test_case(struct test test_case, int *failures,
 				 unsigned int threshold_mb,
 				 unsigned int pattern_seed)
@@ -434,7 +634,7 @@ static int parse_args(int argc, char **argv, unsigned int *threshold_mb,
 	return 0;
 }
 
-#define MAX_TEST 13
+#define MAX_TEST 15
 #define MAX_PERF_TEST 3
 int main(int argc, char **argv)
 {
@@ -443,7 +643,8 @@ int main(int argc, char **argv)
 	unsigned int threshold_mb = VALIDATION_DEFAULT_THRESHOLD;
 	unsigned int pattern_seed;
 	int num_expand_tests = 2;
-	struct test test_cases[MAX_TEST];
+	int num_misc_tests = 2;
+	struct test test_cases[MAX_TEST] = {};
 	struct test perf_test_cases[MAX_PERF_TEST];
 	int page_size;
 	time_t t;
@@ -500,6 +701,15 @@ int main(int argc, char **argv)
 	test_cases[12] = MAKE_TEST(PUD, PUD, _2GB, NON_OVERLAPPING, EXPECT_SUCCESS,
 				   "2GB mremap - Source PUD-aligned, Destination PUD-aligned");
 
+	/* Src and Dest addr 1MB aligned. 5MB mremap. */
+	test_cases[13] = MAKE_TEST(_1MB, _1MB, _5MB, NON_OVERLAPPING, EXPECT_SUCCESS,
+				  "5MB mremap - Source 1MB-aligned, Destination 1MB-aligned");
+
+	/* Src and Dest addr 1MB aligned. 5MB mremap. */
+	test_cases[14] = MAKE_TEST(_1MB, _1MB, _5MB, NON_OVERLAPPING, EXPECT_SUCCESS,
+				  "5MB mremap - Source 1MB-aligned, Dest 1MB-aligned with 40MB Preamble");
+	test_cases[14].config.dest_preamble_size = 10 * _4MB;
+
 	perf_test_cases[0] =  MAKE_TEST(page_size, page_size, _1GB, NON_OVERLAPPING, EXPECT_SUCCESS,
 					"1GB mremap - Source PTE-aligned, Destination PTE-aligned");
 	/*
@@ -515,7 +725,7 @@ int main(int argc, char **argv)
 				(threshold_mb * _1MB >= _1GB);
 
 	ksft_set_plan(ARRAY_SIZE(test_cases) + (run_perf_tests ?
-		      ARRAY_SIZE(perf_test_cases) : 0) + num_expand_tests);
+		      ARRAY_SIZE(perf_test_cases) : 0) + num_expand_tests + num_misc_tests);
 
 	for (i = 0; i < ARRAY_SIZE(test_cases); i++)
 		run_mremap_test_case(test_cases[i], &failures, threshold_mb,
@@ -533,6 +743,9 @@ int main(int argc, char **argv)
 
 	fclose(maps_fp);
 
+	mremap_move_within_range(pattern_seed);
+	mremap_move_1mb_from_start(pattern_seed);
+
 	if (run_perf_tests) {
 		ksft_print_msg("\n%s\n",
 		 "mremap HAVE_MOVE_PMD/PUD optimization time comparison for 1GB region:");