[RFC PATCH v2 8/8] selftest mm/mseal mprotect/munmap/mremap/mmap

[jeffxu]

From: Jeff Xu <jeffxu@xxxxxxxxxx>

selftest for sealing mprotect/munmap/mremap/mmap

Signed-off-by: Jeff Xu <jeffxu@xxxxxxxxxx>
---
 tools/testing/selftests/mm/Makefile     |    1 +
 tools/testing/selftests/mm/mseal_test.c | 1428 +++++++++++++++++++++++
 2 files changed, 1429 insertions(+)
 create mode 100644 tools/testing/selftests/mm/mseal_test.c

diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 6a9fc5693145..0c086cecc093 100644
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -59,6 +59,7 @@ TEST_GEN_FILES += mlock2-tests
 TEST_GEN_FILES += mrelease_test
 TEST_GEN_FILES += mremap_dontunmap
 TEST_GEN_FILES += mremap_test
+TEST_GEN_FILES += mseal_test
 TEST_GEN_FILES += on-fault-limit
 TEST_GEN_FILES += thuge-gen
 TEST_GEN_FILES += transhuge-stress
diff --git a/tools/testing/selftests/mm/mseal_test.c b/tools/testing/selftests/mm/mseal_test.c
new file mode 100644
index 000000000000..d6ae09729394
--- /dev/null
+++ b/tools/testing/selftests/mm/mseal_test.c
@@ -0,0 +1,1428 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sys/mman.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <stdbool.h>
+#include "../kselftest.h"
+#include <syscall.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#ifndef MM_SEAL_MSEAL
+#define MM_SEAL_MSEAL 0x1
+#endif
+
+#ifndef MM_SEAL_MPROTECT
+#define MM_SEAL_MPROTECT 0x2
+#endif
+
+#ifndef MM_SEAL_MUNMAP
+#define MM_SEAL_MUNMAP 0x4
+#endif
+
+#ifndef MM_SEAL_MMAP
+#define MM_SEAL_MMAP 0x8
+#endif
+
+#ifndef MM_SEAL_MREMAP
+#define MM_SEAL_MREMAP 0x10
+#endif
+
+#ifndef DEBUG
+#define LOG_TEST_ENTER()	{}
+#else
+#define LOG_TEST_ENTER()	{ printf("%s\n", __func__); }
+#endif
+
+static int sys_mseal(void *start, size_t len, int types)
+{
+	int sret;
+
+	errno = 0;
+	sret = syscall(__NR_mseal, start, len, types, 0);
+	return sret;
+}
+
+int sys_mprotect(void *ptr, size_t size, unsigned long prot)
+{
+	int sret;
+
+	errno = 0;
+	sret = syscall(SYS_mprotect, ptr, size, prot);
+	return sret;
+}
+
+int sys_munmap(void *ptr, size_t size)
+{
+	int sret;
+
+	errno = 0;
+	sret = syscall(SYS_munmap, ptr, size);
+	return sret;
+}
+
+static int sys_madvise(void *start, size_t len, int types)
+{
+	int sret;
+
+	errno = 0;
+	sret = syscall(__NR_madvise, start, len, types);
+	return sret;
+}
+
+void *addr1 = (void *)0x50000000;
+void *addr2 = (void *)0x50004000;
+void *addr3 = (void *)0x50008000;
+void setup_single_address(int size, void **ptrOut)
+{
+	void *ptr;
+
+	ptr = mmap(NULL, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+	assert(ptr != (void *)-1);
+	*ptrOut = ptr;
+}
+
+void setup_single_fixed_address(int size, void **ptrOut)
+{
+	void *ptr;
+
+	ptr = mmap(addr1, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+	assert(ptr == (void *)addr1);
+
+	*ptrOut = ptr;
+}
+
+void clean_single_address(void *ptr, int size)
+{
+	int ret;
+
+	ret = munmap(ptr, size);
+	assert(!ret);
+}
+
+void seal_mprotect_single_address(void *ptr, int size)
+{
+	int ret;
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MPROTECT);
+	assert(!ret);
+}
+
+static void test_seal_addseals(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_address(size, &ptr);
+
+	/* adding seal one by one */
+	ret = sys_mseal(ptr, size, MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MMAP);
+	assert(!ret);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MREMAP);
+	assert(!ret);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MSEAL);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_addseals_combined(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_address(size, &ptr);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	/* adding multiple seals */
+	ret = sys_mseal(ptr, size,
+			MM_SEAL_MPROTECT | MM_SEAL_MMAP | MM_SEAL_MREMAP |
+			MM_SEAL_MSEAL);
+	assert(!ret);
+
+	/* not adding more seal type, so ok. */
+	ret = sys_mseal(ptr, size,
+			MM_SEAL_MMAP | MM_SEAL_MREMAP | MM_SEAL_MSEAL);
+	assert(!ret);
+
+	/* not adding more seal type, so ok. */
+	ret = sys_mseal(ptr, size, MM_SEAL_MSEAL);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_addseals_reject(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_address(size, &ptr);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MPROTECT | MM_SEAL_MSEAL);
+	assert(!ret);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	/* MM_SEAL_MSEAL is set, so not allow new seal type . */
+	ret = sys_mseal(ptr, size,
+			MM_SEAL_MPROTECT | MM_SEAL_MMAP | MM_SEAL_MSEAL);
+	assert(ret < 0);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MMAP);
+	assert(ret < 0);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MMAP | MM_SEAL_MSEAL);
+	assert(ret < 0);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_unmapped_start(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_address(size, &ptr);
+
+	// munmap 2 pages from ptr.
+	ret = sys_munmap(ptr, 2 * page_size);
+	assert(!ret);
+
+	// mprotect will fail because 2 pages from ptr are unmapped.
+	ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
+	assert(ret < 0);
+
+	// mseal will fail because 2 pages from ptr are unmapped.
+	ret = sys_mseal(ptr, size, MM_SEAL_MSEAL);
+	assert(ret < 0);
+
+	ret = sys_mseal(ptr + 2 * page_size, 2 * page_size, MM_SEAL_MSEAL);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_unmapped_middle(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_address(size, &ptr);
+
+	// munmap 2 pages from ptr + page.
+	ret = sys_munmap(ptr + page_size, 2 * page_size);
+	assert(!ret);
+
+	// mprotect will fail, since size is 4 pages.
+	ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
+	assert(ret < 0);
+
+	// mseal will fail as well.
+	ret = sys_mseal(ptr, size, MM_SEAL_MSEAL);
+	assert(ret < 0);
+
+	/* we still can add seal to the first page and last page*/
+	ret = sys_mseal(ptr, page_size, MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	ret = sys_mseal(ptr + 3 * page_size, page_size,
+			MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_unmapped_end(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_address(size, &ptr);
+
+	// unmap last 2 pages.
+	ret = sys_munmap(ptr + 2 * page_size, 2 * page_size);
+	assert(!ret);
+
+	//mprotect will fail since last 2 pages are unmapped.
+	ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
+	assert(ret < 0);
+
+	//mseal will fail as well.
+	ret = sys_mseal(ptr, size, MM_SEAL_MSEAL);
+	assert(ret < 0);
+
+	/* The first 2 pages is not sealed, and can add seals */
+	ret = sys_mseal(ptr, 2 * page_size, MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_multiple_vmas(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_address(size, &ptr);
+
+	// use mprotect to split the vma into 3.
+	ret = sys_mprotect(ptr + page_size, 2 * page_size,
+			PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	// mprotect will get applied to all 4 pages - 3 VMAs.
+	ret = sys_mprotect(ptr, size, PROT_READ);
+	assert(!ret);
+
+	// use mprotect to split the vma into 3.
+	ret = sys_mprotect(ptr + page_size, 2 * page_size,
+			PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	// mseal get applied to all 4 pages - 3 VMAs.
+	ret = sys_mseal(ptr, size, MM_SEAL_MSEAL);
+	assert(!ret);
+
+	// verify additional seal type will fail after MM_SEAL_MSEAL set.
+	ret = sys_mseal(ptr, page_size, MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(ret < 0);
+
+	ret = sys_mseal(ptr + page_size, 2 * page_size,
+			MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(ret < 0);
+
+	ret = sys_mseal(ptr + 3 * page_size, page_size,
+			MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(ret < 0);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_split_start(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_address(size, &ptr);
+
+	/* use mprotect to split at middle */
+	ret = sys_mprotect(ptr, 2 * page_size, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	/* seal the first page, this will split the VMA */
+	ret = sys_mseal(ptr, page_size, MM_SEAL_MSEAL);
+	assert(!ret);
+
+	/* can't add seal to the first page */
+	ret = sys_mseal(ptr, page_size, MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(ret < 0);
+
+	/* add seal to the remain 3 pages */
+	ret = sys_mseal(ptr + page_size, 3 * page_size,
+			MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_split_end(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_fixed_address(size, &ptr);
+
+	/* use mprotect to split at middle */
+	ret = sys_mprotect(ptr, 2 * page_size, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	/* seal the last page */
+	ret = sys_mseal(ptr + 3 * page_size, page_size, MM_SEAL_MSEAL);
+	assert(!ret);
+
+	/* adding seal to the last page is rejected. */
+	ret = sys_mseal(ptr + 3 * page_size, page_size,
+			MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(ret < 0);
+
+	/* Adding seals to the first 3 pages */
+	ret = sys_mseal(ptr, 3 * page_size, MM_SEAL_MSEAL | MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_invalid_input(void)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_fixed_address(size, &ptr);
+
+	/* invalid flag */
+	ret = sys_mseal(ptr, size, 0x20);
+	assert(ret < 0);
+
+	ret = sys_mseal(ptr, size, 0x31);
+	assert(ret < 0);
+
+	ret = sys_mseal(ptr, size, 0x3F);
+	assert(ret < 0);
+
+	/* unaligned address */
+	ret = sys_mseal(ptr + 1, 2 * page_size, MM_SEAL_MSEAL);
+	assert(ret < 0);
+
+	/* length too big */
+	ret = sys_mseal(ptr, 5 * page_size, MM_SEAL_MSEAL);
+	assert(ret < 0);
+
+	/* start is not in a valid VMA */
+	ret = sys_mseal(ptr - page_size, 5 * page_size, MM_SEAL_MSEAL);
+	assert(ret < 0);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_zero_length(void)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	ret = sys_mprotect(ptr, 0, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	/* seal 0 length will be OK, same as mprotect */
+	ret = sys_mseal(ptr, 0, MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	// verify the 4 pages are not sealed by previous call.
+	ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_twice(void)
+{
+	LOG_TEST_ENTER();
+	int ret;
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+
+	setup_single_address(size, &ptr);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	// apply the same seal will be OK. idempotent.
+	ret = sys_mseal(ptr, size, MM_SEAL_MPROTECT);
+	assert(!ret);
+
+	ret = sys_mseal(ptr, size,
+			MM_SEAL_MPROTECT | MM_SEAL_MMAP | MM_SEAL_MREMAP |
+			MM_SEAL_MSEAL);
+	assert(!ret);
+
+	ret = sys_mseal(ptr, size,
+			MM_SEAL_MPROTECT | MM_SEAL_MMAP | MM_SEAL_MREMAP |
+			MM_SEAL_MSEAL);
+	assert(!ret);
+
+	ret = sys_mseal(ptr, size, MM_SEAL_MSEAL);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_mprotect(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	if (seal)
+		seal_mprotect_single_address(ptr, size);
+
+	ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_start_mprotect(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	if (seal)
+		seal_mprotect_single_address(ptr, page_size);
+
+	// the first page is sealed.
+	ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	// pages after the first page is not sealed.
+	ret = sys_mprotect(ptr + page_size, page_size * 3,
+			PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_end_mprotect(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	if (seal)
+		seal_mprotect_single_address(ptr + page_size, 3 * page_size);
+
+	/* first page is not sealed */
+	ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	/* last 3 page are sealed */
+	ret = sys_mprotect(ptr + page_size, page_size * 3,
+			PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_mprotect_unalign_len(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	if (seal)
+		seal_mprotect_single_address(ptr, page_size * 2 - 1);
+
+	// 2 pages are sealed.
+	ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	ret = sys_mprotect(ptr + page_size * 2, page_size,
+			PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_mprotect_unalign_len_variant_2(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+	if (seal)
+		seal_mprotect_single_address(ptr, page_size * 2 + 1);
+
+	// 3 pages are sealed.
+	ret = sys_mprotect(ptr, page_size * 3, PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	ret = sys_mprotect(ptr + page_size * 3, page_size,
+			PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_mprotect_two_vma(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	/* use mprotect to split */
+	ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	if (seal)
+		seal_mprotect_single_address(ptr, page_size * 4);
+
+	ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	ret = sys_mprotect(ptr + page_size * 2, page_size * 2,
+			PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_mprotect_two_vma_with_split(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	// use mprotect to split as two vma.
+	ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	// mseal can apply across 2 vma, also split them.
+	if (seal)
+		seal_mprotect_single_address(ptr + page_size, page_size * 2);
+
+	// the first page is not sealed.
+	ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	// the second page is sealed.
+	ret = sys_mprotect(ptr + page_size, page_size, PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	// the third page is sealed.
+	ret = sys_mprotect(ptr + 2 * page_size, page_size,
+			PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	// the fouth page is not sealed.
+	ret = sys_mprotect(ptr + 3 * page_size, page_size,
+			PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_mprotect_partial_mprotect(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	// seal one page.
+	if (seal)
+		seal_mprotect_single_address(ptr, page_size);
+
+	// mprotect first 2 page will fail, since the first page are sealed.
+	ret = sys_mprotect(ptr, 2 * page_size, PROT_READ | PROT_WRITE);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_mprotect_two_vma_with_gap(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	// use mprotect to split.
+	ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	// use mprotect to split.
+	ret = sys_mprotect(ptr + 3 * page_size, page_size,
+			PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	// use munmap to free two pages in the middle
+	ret = sys_munmap(ptr + page_size, 2 * page_size);
+	assert(!ret);
+
+	// mprotect will fail, because there is a gap in the address.
+	// notes, internally mprotect still updated the first page.
+	ret = sys_mprotect(ptr, 4 * page_size, PROT_READ);
+	assert(ret < 0);
+
+	// mseal will fail as well.
+	ret = sys_mseal(ptr, 4 * page_size, MM_SEAL_MPROTECT);
+	assert(ret < 0);
+
+	// unlike mprotect, the first page is not sealed.
+	ret = sys_mprotect(ptr, page_size, PROT_READ);
+	assert(ret == 0);
+
+	// the last page is not sealed.
+	ret = sys_mprotect(ptr + 3 * page_size, page_size, PROT_READ);
+	assert(ret == 0);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_mprotect_split(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	//use mprotect to split.
+	ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	//seal all 4 pages.
+	if (seal) {
+		ret = sys_mseal(ptr, 4 * page_size, MM_SEAL_MPROTECT);
+		assert(!ret);
+	}
+
+	//madvice is OK.
+	ret = sys_madvise(ptr, page_size * 2, MADV_WILLNEED);
+	assert(!ret);
+
+	//mprotect is sealed.
+	ret = sys_mprotect(ptr, 2 * page_size, PROT_READ);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+
+	ret = sys_mprotect(ptr + 2 * page_size, 2 * page_size, PROT_READ);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_mprotect_merge(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	// use mprotect to split one page.
+	ret = sys_mprotect(ptr, page_size, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	// seal first two pages.
+	if (seal) {
+		ret = sys_mseal(ptr, 2 * page_size, MM_SEAL_MPROTECT);
+		assert(!ret);
+	}
+
+	ret = sys_madvise(ptr, page_size, MADV_WILLNEED);
+	assert(!ret);
+
+	// 2 pages are sealed.
+	ret = sys_mprotect(ptr, 2 * page_size, PROT_READ);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	// last 2 pages are not sealed.
+	ret = sys_mprotect(ptr + 2 * page_size, 2 * page_size, PROT_READ);
+	assert(ret == 0);
+
+	clean_single_address(ptr, size);
+}
+
+static void test_seal_munmap(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	if (seal) {
+		ret = sys_mseal(ptr, size, MM_SEAL_MUNMAP);
+		assert(!ret);
+	}
+
+	// 4 pages are sealed.
+	ret = sys_munmap(ptr, size);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+}
+
+/*
+ * allocate 4 pages,
+ * use mprotect to split it as two VMAs
+ * seal the whole range
+ * munmap will fail on both
+ */
+static void test_seal_munmap_two_vma(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	/* use mprotect to split */
+	ret = sys_mprotect(ptr, page_size * 2, PROT_READ | PROT_WRITE);
+	assert(!ret);
+
+	if (seal) {
+		ret = sys_mseal(ptr, size, MM_SEAL_MUNMAP);
+		assert(!ret);
+	}
+
+	ret = sys_munmap(ptr, page_size * 2);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+
+	ret = sys_munmap(ptr + page_size, page_size * 2);
+	if (seal)
+		assert(ret < 0);
+	else
+		assert(!ret);
+}
+
+/*
+ * allocate a VMA with 4 pages.
+ * munmap the middle 2 pages.
+ * seal the whole 4 pages, will fail.
+ * note: one of the pages are sealed
+ * munmap the first page will be OK.
+ * munmap the last page will be OK.
+ */
+static void test_seal_munmap_vma_with_gap(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	ret = sys_munmap(ptr + page_size, page_size * 2);
+	assert(!ret);
+
+	if (seal) {
+		// can't have gap in the middle.
+		ret = sys_mseal(ptr, size, MM_SEAL_MUNMAP);
+		assert(ret < 0);
+	}
+
+	ret = sys_munmap(ptr, page_size);
+	assert(!ret);
+
+	ret = sys_munmap(ptr + page_size * 2, page_size);
+	assert(!ret);
+
+	ret = sys_munmap(ptr, size);
+	assert(!ret);
+}
+
+static void test_munmap_start_freed(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+
+	// unmap the first page.
+	ret = sys_munmap(ptr, page_size);
+	assert(!ret);
+
+	// seal the last 3 pages.
+	if (seal) {
+		ret = sys_mseal(ptr + page_size, 3 * page_size, MM_SEAL_MUNMAP);
+		assert(!ret);
+	}
+
+	// unmap from the first page.
+	ret = sys_munmap(ptr, size);
+	if (seal) {
+		assert(ret < 0);
+
+		// use mprotect to verify page is not unmapped.
+		ret = sys_mprotect(ptr + page_size, 3 * page_size, PROT_READ);
+		assert(!ret);
+	} else
+		// note: this will be OK, even the first page is
+		// already unmapped.
+		assert(!ret);
+}
+
+static void test_munmap_end_freed(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+	// unmap last page.
+	ret = sys_munmap(ptr + page_size * 3, page_size);
+	assert(!ret);
+
+	// seal the first 3 pages.
+	if (seal) {
+		ret = sys_mseal(ptr, 3 * page_size, MM_SEAL_MUNMAP);
+		assert(!ret);
+	}
+
+	// unmap all pages.
+	ret = sys_munmap(ptr, size);
+	if (seal) {
+		assert(ret < 0);
+
+		// use mprotect to verify page is not unmapped.
+		ret = sys_mprotect(ptr, 3 * page_size, PROT_READ);
+		assert(!ret);
+	} else
+		assert(!ret);
+}
+
+static void test_munmap_middle_freed(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+
+	setup_single_address(size, &ptr);
+	// unmap 2 pages in the middle.
+	ret = sys_munmap(ptr + page_size, page_size * 2);
+	assert(!ret);
+
+	// seal the first page.
+	if (seal) {
+		ret = sys_mseal(ptr, page_size, MM_SEAL_MUNMAP);
+		assert(!ret);
+	}
+
+	// munmap all 4 pages.
+	ret = sys_munmap(ptr, size);
+	if (seal) {
+		assert(ret < 0);
+
+		// use mprotect to verify page is not unmapped.
+		ret = sys_mprotect(ptr, page_size, PROT_READ);
+		assert(!ret);
+	} else
+		assert(!ret);
+}
+
+void test_seal_mremap_shrink(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(size, &ptr);
+
+	if (seal) {
+		ret = sys_mseal(ptr, size, MM_SEAL_MREMAP);
+		assert(!ret);
+	}
+
+	// shrink from 4 pages to 2 pages.
+	ret2 = mremap(ptr, size, 2 * page_size, 0, 0);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else {
+		assert(ret2 != MAP_FAILED);
+		clean_single_address(ret2, 2 * page_size);
+	}
+	clean_single_address(ptr, size);
+}
+
+void test_seal_mremap_expand(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(size, &ptr);
+	// ummap last 2 pages.
+	ret = sys_munmap(ptr + 2 * page_size, 2 * page_size);
+	assert(!ret);
+
+	if (seal) {
+		ret = sys_mseal(ptr, 2 * page_size, MM_SEAL_MREMAP);
+		assert(!ret);
+	}
+
+	// expand from 2 page to 4 pages.
+	ret2 = mremap(ptr, 2 * page_size, 4 * page_size, 0, 0);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else {
+		assert(ret2 == ptr);
+		clean_single_address(ret2, 4 * page_size);
+	}
+	clean_single_address(ptr, size);
+}
+
+void test_seal_mremap_move(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(size, &ptr);
+	if (seal) {
+		ret = sys_mseal(ptr, size, MM_SEAL_MREMAP);
+		assert(!ret);
+	}
+
+	// move from ptr to fixed address.
+	ret2 = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, addr1);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else {
+		assert(ret2 != MAP_FAILED);
+		clean_single_address(ret2, size);
+	}
+	clean_single_address(ptr, size);
+}
+
+void test_seal_mmap_overwrite_prot(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(size, &ptr);
+
+	if (seal) {
+		ret = sys_mseal(ptr, size, MM_SEAL_MMAP);
+		assert(!ret);
+	}
+
+	// use mmap to change protection.
+	ret2 = mmap(ptr, size, PROT_NONE,
+			MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else
+		assert(ret2 == ptr);
+
+	clean_single_address(ptr, size);
+}
+
+void test_seal_mremap_shrink_fixed(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	void *newAddr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(size, &ptr);
+	setup_single_fixed_address(size, &newAddr);
+
+	if (seal) {
+		ret = sys_mseal(ptr, size, MM_SEAL_MREMAP);
+		assert(!ret);
+	}
+
+	// mremap to move and shrink to fixed address
+	ret2 = mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED,
+			newAddr);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else
+		assert(ret2 == newAddr);
+
+	clean_single_address(ptr, size);
+	clean_single_address(newAddr, size);
+}
+
+void test_seal_mremap_expand_fixed(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	void *newAddr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(page_size, &ptr);
+	setup_single_fixed_address(size, &newAddr);
+
+	if (seal) {
+		ret = sys_mseal(newAddr, size, MM_SEAL_MREMAP);
+		assert(!ret);
+	}
+
+	// mremap to move and expand to fixed address
+	ret2 = mremap(ptr, page_size, size, MREMAP_MAYMOVE | MREMAP_FIXED,
+			newAddr);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else
+		assert(ret2 == newAddr);
+
+	clean_single_address(ptr, page_size);
+	clean_single_address(newAddr, size);
+}
+
+void test_seal_mremap_move_fixed(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	void *newAddr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(size, &ptr);
+	setup_single_fixed_address(size, &newAddr);
+
+	if (seal) {
+		ret = sys_mseal(newAddr, size, MM_SEAL_MREMAP);
+		assert(!ret);
+	}
+
+	// mremap to move to fixed address
+	ret2 = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, newAddr);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else
+		assert(ret2 == newAddr);
+
+	clean_single_address(ptr, page_size);
+	clean_single_address(newAddr, size);
+}
+
+void test_seal_mremap_move_fixed_zero(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	void *newAddr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(size, &ptr);
+
+	if (seal) {
+		ret = sys_mseal(ptr, size, MM_SEAL_MREMAP);
+		assert(!ret);
+	}
+
+	/*
+	 * MREMAP_FIXED can move the mapping to zero address
+	 */
+	ret2 = mremap(ptr, size, 2 * page_size, MREMAP_MAYMOVE | MREMAP_FIXED,
+			0);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else {
+		assert(ret2 == 0);
+		clean_single_address(ret2, 2 * page_size);
+	}
+	clean_single_address(ptr, size);
+}
+
+void test_seal_mremap_move_dontunmap(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	void *newAddr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(size, &ptr);
+
+	if (seal) {
+		ret = sys_mseal(ptr, size, MM_SEAL_MREMAP);
+		assert(!ret);
+	}
+
+	// mremap to move, and don't unmap src addr.
+	ret2 = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_DONTUNMAP, 0);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else {
+		assert(ret2 != MAP_FAILED);
+		clean_single_address(ret2, size);
+	}
+
+	clean_single_address(ptr, page_size);
+}
+
+void test_seal_mremap_move_dontunmap_anyaddr(bool seal)
+{
+	LOG_TEST_ENTER();
+	void *ptr;
+	void *newAddr;
+	unsigned long page_size = getpagesize();
+	unsigned long size = 4 * page_size;
+	int ret;
+	void *ret2;
+
+	setup_single_address(size, &ptr);
+
+	if (seal) {
+		ret = sys_mseal(ptr, size, MM_SEAL_MREMAP);
+		assert(!ret);
+	}
+
+	/*
+	 * The 0xdeaddead should not have effect on dest addr
+	 * when MREMAP_DONTUNMAP is set.
+	 */
+	ret2 = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_DONTUNMAP,
+			0xdeaddead);
+	if (seal) {
+		assert(ret2 == MAP_FAILED);
+		assert(errno == EACCES);
+	} else {
+		assert(ret2 != MAP_FAILED);
+		assert((long)ret2 != 0xdeaddead);
+		clean_single_address(ret2, size);
+	}
+
+	clean_single_address(ptr, page_size);
+}
+
+int main(int argc, char **argv)
+{
+	test_seal_invalid_input();
+	test_seal_addseals();
+	test_seal_addseals_combined();
+	test_seal_addseals_reject();
+	test_seal_unmapped_start();
+	test_seal_unmapped_middle();
+	test_seal_unmapped_end();
+	test_seal_multiple_vmas();
+	test_seal_split_start();
+	test_seal_split_end();
+
+	test_seal_zero_length();
+	test_seal_twice();
+
+	test_seal_mprotect(false);
+	test_seal_mprotect(true);
+
+	test_seal_start_mprotect(false);
+	test_seal_start_mprotect(true);
+
+	test_seal_end_mprotect(false);
+	test_seal_end_mprotect(true);
+
+	test_seal_mprotect_unalign_len(false);
+	test_seal_mprotect_unalign_len(true);
+
+	test_seal_mprotect_unalign_len_variant_2(false);
+	test_seal_mprotect_unalign_len_variant_2(true);
+
+	test_seal_mprotect_two_vma(false);
+	test_seal_mprotect_two_vma(true);
+
+	test_seal_mprotect_two_vma_with_split(false);
+	test_seal_mprotect_two_vma_with_split(true);
+
+	test_seal_mprotect_partial_mprotect(false);
+	test_seal_mprotect_partial_mprotect(true);
+
+	test_seal_mprotect_two_vma_with_gap(false);
+	test_seal_mprotect_two_vma_with_gap(true);
+
+	test_seal_mprotect_merge(false);
+	test_seal_mprotect_merge(true);
+
+	test_seal_mprotect_split(false);
+	test_seal_mprotect_split(true);
+
+	test_seal_munmap(false);
+	test_seal_munmap(true);
+	test_seal_munmap_two_vma(false);
+	test_seal_munmap_two_vma(true);
+	test_seal_munmap_vma_with_gap(false);
+	test_seal_munmap_vma_with_gap(true);
+
+	test_munmap_start_freed(false);
+	test_munmap_start_freed(true);
+	test_munmap_middle_freed(false);
+	test_munmap_middle_freed(true);
+	test_munmap_end_freed(false);
+	test_munmap_end_freed(true);
+
+	test_seal_mremap_shrink(false);
+	test_seal_mremap_shrink(true);
+	test_seal_mremap_expand(false);
+	test_seal_mremap_expand(true);
+	test_seal_mremap_move(false);
+	test_seal_mremap_move(true);
+
+	test_seal_mremap_shrink_fixed(false);
+	test_seal_mremap_shrink_fixed(true);
+	test_seal_mremap_expand_fixed(false);
+	test_seal_mremap_expand_fixed(true);
+	test_seal_mremap_move_fixed(false);
+	test_seal_mremap_move_fixed(true);
+	test_seal_mremap_move_dontunmap(false);
+	test_seal_mremap_move_dontunmap(true);
+	test_seal_mremap_move_fixed_zero(false);
+	test_seal_mremap_move_fixed_zero(true);
+	test_seal_mremap_move_dontunmap_anyaddr(false);
+	test_seal_mremap_move_dontunmap_anyaddr(true);
+
+	test_seal_mmap_overwrite_prot(false);
+	test_seal_mmap_overwrite_prot(true);
+
+	printf("OK\n");
+	return 0;
+}
-- 
2.42.0.655.g421f12c284-goog