Re: [RFC PATCH v4 3/4] selftest mm/mseal memory sealing

[Muhammad Usama Anjum]

You have used ksft_print_msg() only. Can you please udpate the test to use
more TAP macros for increased readability and printing test output. We
don't want to terminate the test if one test fails because of assert. We
want the sub-tests to get executed indepdendent of other tests.

ksft_test_result(condition, fmt, ...);
ksft_test_result_pass(fmt, ...);

See some examples below:

On 1/4/24 11:51 PM, jeffxu@xxxxxxxxxxxx wrote:
> From: Jeff Xu <jeffxu@xxxxxxxxxxxx>
> 
> selftest for memory sealing change in mmap() and mseal().
> 
> Signed-off-by: Jeff Xu <jeffxu@xxxxxxxxxxxx>
> ---
>  tools/testing/selftests/mm/.gitignore   |    1 +
>  tools/testing/selftests/mm/Makefile     |    1 +
>  tools/testing/selftests/mm/mseal_test.c | 1971 +++++++++++++++++++++++
>  3 files changed, 1973 insertions(+)
>  create mode 100644 tools/testing/selftests/mm/mseal_test.c
> 
> diff --git a/tools/testing/selftests/mm/.gitignore b/tools/testing/selftests/mm/.gitignore
> index 4ff10ea61461..76474c51c786 100644
> --- a/tools/testing/selftests/mm/.gitignore
> +++ b/tools/testing/selftests/mm/.gitignore
> @@ -46,3 +46,4 @@ gup_longterm
>  mkdirty
>  va_high_addr_switch
>  hugetlb_fault_after_madv
> +mseal_test
> diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
> index dede0bcf97a3..652c07ff81f5 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 += pagemap_ioctl
>  TEST_GEN_FILES += thuge-gen
> diff --git a/tools/testing/selftests/mm/mseal_test.c b/tools/testing/selftests/mm/mseal_test.c
> new file mode 100644
> index 000000000000..a916d30e97c2
> --- /dev/null
> +++ b/tools/testing/selftests/mm/mseal_test.c
> @@ -0,0 +1,1971 @@
> +// 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>
> +#include <fcntl.h>
> +#include <assert.h>
> +#include <sys/ioctl.h>
> +#include <sys/vfs.h>
> +#include <sys/stat.h>
> +
> +/*
> + * need those definition for manually build using gcc.
> + * gcc -I ../../../../usr/include   -DDEBUG -O3  -DDEBUG -O3 mseal_test.c -o mseal_test
> + */
> +#ifndef MAP_SEALABLE
> +#define MAP_SEALABLE 0x8000000
> +#endif
> +
> +#ifndef PROT_SEAL
> +#define PROT_SEAL 0x04000000
> +#endif
> +
> +#ifndef PKEY_DISABLE_ACCESS
> +# define PKEY_DISABLE_ACCESS    0x1
> +#endif
> +
> +#ifndef PKEY_DISABLE_WRITE
> +# define PKEY_DISABLE_WRITE     0x2
> +#endif
> +
> +#ifndef PKEY_BITS_PER_KEY
> +#define PKEY_BITS_PER_PKEY      2
> +#endif
> +
> +#ifndef PKEY_MASK
> +#define PKEY_MASK       (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE)
> +#endif
> +
> +#ifndef DEBUG
> +#define LOG_TEST_ENTER()	{}
> +#else
> +#define LOG_TEST_ENTER()	{ksft_print_msg("%s\n", __func__); }
> +#endif
> +
> +#ifndef u64
> +#define u64 unsigned long long
> +#endif
> +
> +static unsigned long get_vma_size(void *addr)
> +{
> +	FILE *maps;
> +	char line[256];
> +	int size = 0;
> +	uintptr_t  addr_start, addr_end;
> +
> +	maps = fopen("/proc/self/maps", "r");
> +	if (!maps)
> +		return 0;
> +
> +	while (fgets(line, sizeof(line), maps)) {
> +		if (sscanf(line, "%lx-%lx", &addr_start, &addr_end) == 2) {
> +			if (addr_start == (uintptr_t) addr) {
> +				size = addr_end - addr_start;
> +				break;
> +			}
> +		}
> +	}
> +	fclose(maps);
> +	return size;
> +}
> +
> +/*
> + * define sys_xyx to call syscall directly.
> + */
> +static int sys_mseal(void *start, size_t len)
> +{
> +	int sret;
> +
> +	errno = 0;
> +	sret = syscall(__NR_mseal, start, len, 0);
> +	return sret;
> +}
> +
> +static int sys_mprotect(void *ptr, size_t size, unsigned long prot)
> +{
> +	int sret;
> +
> +	errno = 0;
> +	sret = syscall(SYS_mprotect, ptr, size, prot);
> +	return sret;
> +}
> +
> +static int sys_mprotect_pkey(void *ptr, size_t size, unsigned long orig_prot,
> +		unsigned long pkey)
> +{
> +	int sret;
> +
> +	errno = 0;
> +	sret = syscall(__NR_pkey_mprotect, ptr, size, orig_prot, pkey);
> +	return sret;
> +}
> +
> +/*
> + * define sys_xyx to call syscall directly.
> + */
> +static void *sys_mmap(void *addr, unsigned long len, unsigned long prot,
> +	unsigned long flags, unsigned long fd, unsigned long offset)
> +{
> +	void *sret;
> +
> +	errno = 0;
> +	sret = (void *) syscall(__NR_mmap, addr, len, prot,
> +		flags, fd, offset);
> +	return sret;
> +}
> +
> +static 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;
> +}
> +
> +static int sys_pkey_alloc(unsigned long flags, unsigned long init_val)
> +{
> +	int ret = syscall(SYS_pkey_alloc, flags, init_val);
> +
> +	return ret;
> +}
> +
> +static unsigned int __read_pkey_reg(void)
> +{
> +	unsigned int eax, edx;
> +	unsigned int ecx = 0;
> +	unsigned int pkey_reg;
> +
> +	asm volatile(".byte 0x0f,0x01,0xee\n\t"
> +			: "=a" (eax), "=d" (edx)
> +			: "c" (ecx));
> +	pkey_reg = eax;
> +	return pkey_reg;
> +}
> +
> +static void __write_pkey_reg(u64 pkey_reg)
> +{
> +	unsigned int eax = pkey_reg;
> +	unsigned int ecx = 0;
> +	unsigned int edx = 0;
> +
> +	asm volatile(".byte 0x0f,0x01,0xef\n\t"
> +			: : "a" (eax), "c" (ecx), "d" (edx));
> +	assert(pkey_reg == __read_pkey_reg());
> +}
> +
> +static unsigned long pkey_bit_position(int pkey)
> +{
> +	return pkey * PKEY_BITS_PER_PKEY;
> +}
> +
> +static u64 set_pkey_bits(u64 reg, int pkey, u64 flags)
> +{
> +	unsigned long shift = pkey_bit_position(pkey);
> +
> +	/* mask out bits from pkey in old value */
> +	reg &= ~((u64)PKEY_MASK << shift);
> +	/* OR in new bits for pkey */
> +	reg |= (flags & PKEY_MASK) << shift;
> +	return reg;
> +}
> +
> +static void set_pkey(int pkey, unsigned long pkey_value)
> +{
> +	unsigned long mask = (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE);
> +	u64 new_pkey_reg;
> +
> +	assert(!(pkey_value & ~mask));
> +	new_pkey_reg = set_pkey_bits(__read_pkey_reg(), pkey, pkey_value);
> +	__write_pkey_reg(new_pkey_reg);
> +}
> +
> +static void setup_single_address(int size, void **ptrOut)
> +{
> +	void *ptr;
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE | MAP_SEALABLE, -1, 0);
> +	assert(ptr != (void *)-1);
ksft_exit_fail_msg() here as this this fetal error and test should abort.

> +	*ptrOut = ptr;
> +}
> +
> +static void setup_single_address_sealable(int size, void **ptrOut, bool sealable)
> +{
> +	void *ptr;
> +	unsigned long mapflags = MAP_ANONYMOUS | MAP_PRIVATE;
> +
> +	if (sealable)
> +		mapflags |= MAP_SEALABLE;
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ, mapflags, -1, 0);
> +	assert(ptr != (void *)-1);
> +	*ptrOut = ptr;
> +}
> +
> +static void setup_single_address_rw_sealable(int size, void **ptrOut, bool sealable)
> +{
> +	void *ptr;
> +	unsigned long mapflags = MAP_ANONYMOUS | MAP_PRIVATE;
> +
> +	if (sealable)
> +		mapflags |= MAP_SEALABLE;
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ | PROT_WRITE, mapflags, -1, 0);
> +	assert(ptr != (void *)-1);
> +	*ptrOut = ptr;
> +}
> +
> +static void clean_single_address(void *ptr, int size)
> +{
> +	int ret;
> +
> +	ret = munmap(ptr, size);
> +	assert(!ret);
> +}
> +
> +static void seal_single_address(void *ptr, int size)
> +{
> +	int ret;
> +
> +	ret = sys_mseal(ptr, size);
> +	assert(!ret);
> +}
> +
> +static void test_seal_addseal(void)
> +{
> +	LOG_TEST_ENTER();
Move this to after variable declarations. Not sure why you aren't getting
warning already that you are writing code before variable declarations.

> +	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);
ksft_test_result(!ret, "mseal syscall\n");

> +	assert(!ret);
> +}
> +
> +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);
> +	assert(ret < 0);
> +
> +	ret = sys_mseal(ptr + 2 * page_size, 2 * page_size);
> +	assert(!ret);
> +}
> +
> +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);
> +	assert(ret < 0);
> +
> +	/* we still can add seal to the first page and last page*/
> +	ret = sys_mseal(ptr, page_size);
> +	assert(!ret);
> +
> +	ret = sys_mseal(ptr + 3 * page_size, page_size);
> +	assert(!ret);
> +}
> +
> +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);
> +	assert(ret < 0);
> +
> +	/* The first 2 pages is not sealed, and can add seals */
> +	ret = sys_mseal(ptr, 2 * page_size);
> +	assert(!ret);
> +}
> +
> +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);
> +	assert(!ret);
> +}
> +
> +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);
> +	assert(!ret);
> +
> +	/* add seal to the remain 3 pages */
> +	ret = sys_mseal(ptr + page_size, 3 * page_size);
> +	assert(!ret);
> +}
> +
> +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_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);
> +	assert(!ret);
> +
> +	/* Adding seals to the first 3 pages */
> +	ret = sys_mseal(ptr, 3 * page_size);
> +	assert(!ret);
> +}
> +
> +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_address(8 * page_size, &ptr);
> +	clean_single_address(ptr + 4 * page_size, 4 * page_size);
> +
> +	/* invalid flag */
> +	ret = syscall(__NR_mseal, ptr, size, 0x20);
> +	assert(ret < 0);
> +
> +	/* unaligned address */
> +	ret = sys_mseal(ptr + 1, 2 * page_size);
> +	assert(ret < 0);
> +
> +	/* length too big */
> +	ret = sys_mseal(ptr, 5 * page_size);
> +	assert(ret < 0);
> +
> +	/* start is not in a valid VMA */
> +	ret = sys_mseal(ptr - page_size, 5 * page_size);
> +	assert(ret < 0);
> +}
> +
> +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);
> +	assert(!ret);
> +
> +	/* verify the 4 pages are not sealed by previous call. */
> +	ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
> +	assert(!ret);
> +}
> +
> +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);
> +	assert(!ret);
> +
> +	/* apply the same seal will be OK. idempotent. */
> +	ret = sys_mseal(ptr, size);
> +	assert(!ret);
> +}
> +
> +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_single_address(ptr, size);
> +
> +	ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
> +	if (seal)
> +		assert(ret < 0);
> +	else
> +		assert(!ret);
> +}
> +
> +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_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);
> +}
> +
> +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_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);
> +}
> +
> +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_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);
> +}
> +
> +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_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);
> +}
> +
> +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_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);
> +}
> +
> +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_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);
> +}
> +
> +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_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);
> +}
> +
> +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);
> +	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);
> +}
> +
> +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);
> +		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);
> +}
> +
> +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);
> +		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);
> +}
> +
> +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);
> +		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
> + */
ksft* macros can print this information to console for better view of which
test failed.

> +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);
> +		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);
> +		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);
> +		assert(!ret);
> +	}
> +
> +	/* unmap from the first page. */
> +	ret = sys_munmap(ptr, size);
> +	if (seal)
> +		assert(ret < 0);
> +	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);
> +		assert(!ret);
> +	}
> +
> +	/* unmap all pages. */
> +	ret = sys_munmap(ptr, size);
> +	if (seal)
> +		assert(ret < 0);
> +	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);
> +		assert(!ret);
> +	}
> +
> +	/* munmap all 4 pages. */
> +	ret = sys_munmap(ptr, size);
> +	if (seal)
> +		assert(ret < 0);
> +	else
> +		assert(!ret);
> +}
> +
> +static 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);
> +		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);
> +
> +	}
> +}
> +
> +static 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);
> +		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);
> +
> +	}
> +}
> +
> +static void test_seal_mremap_move(bool seal)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr, *newPtr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = page_size;
> +	int ret;
> +	void *ret2;
> +
> +	setup_single_address(size, &ptr);
> +	setup_single_address(size, &newPtr);
> +	clean_single_address(newPtr, size);
> +
> +	if (seal) {
> +		ret = sys_mseal(ptr, size);
> +		assert(!ret);
> +	}
> +
> +	/* move from ptr to fixed address. */
> +	ret2 = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, newPtr);
> +	if (seal) {
> +		assert(ret2 == MAP_FAILED);
> +		assert(errno == EACCES);
> +	} else {
> +		assert(ret2 != MAP_FAILED);
> +
> +	}
> +}
> +
> +static 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);
> +		assert(!ret);
> +	}
> +
> +	/* use mmap to change protection. */
> +	ret2 = sys_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);
> +}
> +
> +static void test_seal_mmap_expand(bool seal)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 12 * page_size;
> +	int ret;
> +	void *ret2;
> +
> +	setup_single_address(size, &ptr);
> +	/* ummap last 4 pages. */
> +	ret = sys_munmap(ptr + 8 * page_size, 4 * page_size);
> +	assert(!ret);
> +
> +	if (seal) {
> +		ret = sys_mseal(ptr, 8 * page_size);
> +		assert(!ret);
> +	}
> +
> +	/* use mmap to expand. */
> +	ret2 = sys_mmap(ptr, size, PROT_READ,
> +			MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
> +	if (seal) {
> +		assert(ret2 == MAP_FAILED);
> +		assert(errno == EACCES);
> +	} else
> +		assert(ret2 == ptr);
> +}
> +
> +static void test_seal_mmap_shrink(bool seal)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 12 * page_size;
> +	int ret;
> +	void *ret2;
> +
> +	setup_single_address(size, &ptr);
> +
> +	if (seal) {
> +		ret = sys_mseal(ptr, size);
> +		assert(!ret);
> +	}
> +
> +	/* use mmap to shrink. */
> +	ret2 = sys_mmap(ptr, 8 * page_size, PROT_READ,
> +			MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
> +	if (seal) {
> +		assert(ret2 == MAP_FAILED);
> +		assert(errno == EACCES);
> +	} else
> +		assert(ret2 == ptr);
> +}
> +
> +static 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_address(size, &newAddr);
> +
> +	if (seal) {
> +		ret = sys_mseal(ptr, size);
> +		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);
> +}
> +
> +static 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_address(size, &newAddr);
> +
> +	if (seal) {
> +		ret = sys_mseal(newAddr, size);
> +		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);
> +}
> +
> +static 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_address(size, &newAddr);
> +
> +	if (seal) {
> +		ret = sys_mseal(newAddr, size);
> +		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);
> +}
> +
> +static 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);
> +		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);
> +
> +	}
> +}
> +
> +static 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);
> +		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);
> +
> +	}
> +}
> +
> +static 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);
> +		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);
> +
> +	}
> +}
> +
> +
> +static void test_seal_mmap_seal(void)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +	int ret;
> +	void *ret2;
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ | PROT_SEAL, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
> +	assert(ptr != (void *)-1);
> +
> +	ret = sys_munmap(ptr, size);
> +	assert(ret < 0);
> +
> +	ret = sys_mprotect(ptr, size, PROT_READ | PROT_WRITE);
> +	assert(ret < 0);
> +}
> +
> +static void test_seal_merge_and_split(void)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size;
> +	int ret;
> +	void *ret2;
> +
> +	/* (24 RO) */
> +	setup_single_address(24 * page_size, &ptr);
> +
> +	/* use mprotect(NONE) to set out boundary */
> +	/* (1 NONE) (22 RO) (1 NONE) */
> +	ret = sys_mprotect(ptr, page_size, PROT_NONE);
> +	assert(!ret);
> +	ret = sys_mprotect(ptr + 23 * page_size, page_size, PROT_NONE);
> +	assert(!ret);
> +	size = get_vma_size(ptr + page_size);
> +	assert(size == 22 * page_size);
> +
> +	/* use mseal to split from beginning */
> +	/* (1 NONE) (1 RO_SEAL) (21 RO) (1 NONE) */
> +	ret = sys_mseal(ptr + page_size, page_size);
> +	assert(!ret);
> +	size = get_vma_size(ptr + page_size);
> +	assert(size == page_size);
> +	size = get_vma_size(ptr + 2 * page_size);
> +	assert(size == 21 * page_size);
> +
> +	/* use mseal to split from the end. */
> +	/* (1 NONE) (1 RO_SEAL) (20 RO) (1 RO_SEAL) (1 NONE) */
> +	ret = sys_mseal(ptr + 22 * page_size, page_size);
> +	assert(!ret);
> +	size = get_vma_size(ptr + 22 * page_size);
> +	assert(size == page_size);
> +	size = get_vma_size(ptr + 2 * page_size);
> +	assert(size == 20 * page_size);
> +
> +	/* merge with prev. */
> +	/* (1 NONE) (2 RO_SEAL) (19 RO) (1 RO_SEAL) (1 NONE) */
> +	ret = sys_mseal(ptr + 2 * page_size, page_size);
> +	assert(!ret);
> +	size = get_vma_size(ptr +  page_size);
> +	assert(size ==  2 * page_size);
> +
> +	/* merge with after. */
> +	/* (1 NONE) (2 RO_SEAL) (18 RO) (2 RO_SEALS) (1 NONE) */
> +	ret = sys_mseal(ptr + 21 * page_size, page_size);
> +	assert(!ret);
> +	size = get_vma_size(ptr +  21 * page_size);
> +	assert(size ==  2 * page_size);
> +
> +	/* split and merge from prev */
> +	/* (1 NONE) (3 RO_SEAL) (17 RO) (2 RO_SEALS) (1 NONE) */
> +	ret = sys_mseal(ptr + 2 * page_size, 2 * page_size);
> +	assert(!ret);
> +	size = get_vma_size(ptr +  1 * page_size);
> +	assert(size ==  3 * page_size);
> +	ret = sys_munmap(ptr + page_size,  page_size);
> +	assert(ret < 0);
> +	ret = sys_mprotect(ptr + 2 * page_size, page_size,  PROT_NONE);
> +	assert(ret < 0);
> +
> +	/* split and merge from next */
> +	/* (1 NONE) (3 RO_SEAL) (16 RO) (3 RO_SEALS) (1 NONE) */
> +	ret = sys_mseal(ptr + 20 * page_size, 2 * page_size);
> +	assert(!ret);
> +	size = get_vma_size(ptr +  20 * page_size);
> +	assert(size ==  3 * page_size);
> +
> +	/* merge from middle of prev and middle of next. */
> +	/* (1 NONE) (22 RO_SEAL) (1 NONE) */
> +	ret = sys_mseal(ptr + 2 * page_size, 20 * page_size);
> +	assert(!ret);
> +	size = get_vma_size(ptr +  page_size);
> +	assert(size ==  22 * page_size);
> +}
> +
> +static void test_seal_mmap_merge(void)
> +{
> +	LOG_TEST_ENTER();
> +
> +	void *ptr, *ptr2;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size;
> +	int ret;
> +	void *ret2;
> +
> +	/* (24 RO) */
> +	setup_single_address(24 * page_size, &ptr);
> +
> +	/* use mprotect(NONE) to set out boundary */
> +	/* (1 NONE) (22 RO) (1 NONE) */
> +	ret = sys_mprotect(ptr, page_size, PROT_NONE);
> +	assert(!ret);
> +	ret = sys_mprotect(ptr + 23 * page_size, page_size, PROT_NONE);
> +	assert(!ret);
> +	size = get_vma_size(ptr + page_size);
> +	assert(size == 22 * page_size);
> +
> +	/* use munmap to free 2 segment of memory. */
> +	/* (1 NONE) (1 free) (20 RO) (1 free) (1 NONE) */
> +	ret = sys_munmap(ptr + page_size, page_size);
> +	assert(!ret);
> +
> +	ret = sys_munmap(ptr + 22 * page_size, page_size);
> +	assert(!ret);
> +
> +	/* apply seal to the middle */
> +	/* (1 NONE) (1 free) (20 RO_SEAL) (1 free) (1 NONE) */
> +	ret = sys_mseal(ptr + 2 * page_size, 20 * page_size);
> +	assert(!ret);
> +	size = get_vma_size(ptr + 2 * page_size);
> +	assert(size == 20 * page_size);
> +
> +	/* allocate a mapping at beginning, and make sure it merges. */
> +	/* (1 NONE) (21 RO_SEAL) (1 free) (1 NONE) */
> +	ptr2 = sys_mmap(ptr + page_size, page_size, PROT_READ | PROT_SEAL,
> +		MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
> +	assert(ptr != (void *)-1);
> +	size = get_vma_size(ptr + page_size);
> +	assert(size == 21 * page_size);
> +
> +	/* allocate a mapping at end, and make sure it merges. */
> +	/* (1 NONE) (22 RO_SEAL) (1 NONE) */
> +	ptr2 = sys_mmap(ptr + 22 * page_size, page_size, PROT_READ | PROT_SEAL,
> +		MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
> +	assert(ptr != (void *)-1);
> +	size = get_vma_size(ptr + page_size);
> +	assert(size == 22 * page_size);
> +}
> +
> +static void test_not_sealable(void)
> +{
> +	LOG_TEST_ENTER();
> +	int ret;
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
> +	assert(ptr != (void *)-1);
> +
> +	ret = sys_mseal(ptr, size);
> +	assert(ret < 0);
> +}
> +
> +static void test_mmap_fixed_change_to_sealable(void)
> +{
> +	LOG_TEST_ENTER();
> +	int ret;
> +	void *ptr, *ptr2;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
> +	assert(ptr != (void *)-1);
> +
> +	ret = sys_mseal(ptr, size);
> +	assert(ret < 0);
> +
> +	ptr2 = sys_mmap(ptr, size, PROT_READ,
> +		MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE | MAP_SEALABLE, -1, 0);
> +	assert(ptr2 == ptr);
> +
> +	ret = sys_mseal(ptr, size);
> +	assert(!ret);
> +}
> +
> +static void test_mmap_fixed_change_to_not_sealable(void)
> +{
> +	LOG_TEST_ENTER();
> +	int ret;
> +	void *ptr, *ptr2;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE | MAP_SEALABLE, -1, 0);
> +	assert(ptr != (void *)-1);
> +
> +	ptr2 = sys_mmap(ptr, size, PROT_READ,
> +		MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
> +	assert(ptr2 == ptr);
> +
> +	ret = sys_mseal(ptr, size);
> +	assert(ret < 0);
> +}
> +
> +static void test_merge_sealable(void)
> +{
> +	LOG_TEST_ENTER();
> +	int ret;
> +	void *ptr, *ptr2;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size;
> +
> +	/* (24 RO) */
> +	setup_single_address(24 * page_size, &ptr);
> +
> +	/* use mprotect(NONE) to set out boundary */
> +	/* (1 NONE) (22 RO) (1 NONE) */
> +	ret = sys_mprotect(ptr, page_size, PROT_NONE);
> +	assert(!ret);
> +	ret = sys_mprotect(ptr + 23 * page_size, page_size, PROT_NONE);
> +	assert(!ret);
> +	size = get_vma_size(ptr + page_size);
> +	assert(size == 22 * page_size);
> +
> +	/* (1 NONE) (RO) (4 free) (17 RO) (1 NONE) */
> +	ret = sys_munmap(ptr + 2 * page_size,  4 * page_size);
> +	assert(!ret);
> +	size = get_vma_size(ptr + page_size);
> +	assert(size == 1 * page_size);
> +	size = get_vma_size(ptr +  6 * page_size);
> +	assert(size == 17 * page_size);
> +
> +	/* (1 NONE) (RO) (1 free) (2 RO) (1 free) (17 RO) (1 NONE) */
> +	ptr2 = sys_mmap(ptr + 3 * page_size, 2 * page_size, PROT_READ,
> +		MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE | MAP_SEALABLE, -1, 0);
> +	size = get_vma_size(ptr + 3 * page_size);
> +	assert(size == 2 * page_size);
> +
> +	/* (1 NONE) (RO) (1 free) (20 RO) (1 NONE) */
> +	ptr2 = sys_mmap(ptr + 5 * page_size, 1 * page_size, PROT_READ,
> +		MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE | MAP_SEALABLE, -1, 0);
> +	assert(ptr2 != (void *)-1);
> +	size = get_vma_size(ptr + 3 * page_size);
> +	assert(size == 20 * page_size);
> +
> +	/* (1 NONE) (RO) (1 free) (19 RO) (1 RO_SB) (1 NONE) */
> +	ret = sys_mseal(ptr + 22 * page_size, page_size);
> +	assert(!ret);
> +
> +	/* (1 NONE) (RO) (not sealable) (19 RO) (1 RO_SB) (1 NONE) */
> +	ptr2 = sys_mmap(ptr + 2 * page_size, page_size, PROT_READ,
> +		MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
> +	assert(ptr2 != (void *)-1);
> +	size = get_vma_size(ptr + page_size);
> +	assert(size == page_size);
> +	size = get_vma_size(ptr + 2 * page_size);
> +	assert(size == page_size);
> +}
> +
> +static void test_seal_discard_ro_anon_on_rw(bool seal)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +	int ret;
> +
> +	setup_single_address_rw_sealable(size, &ptr, seal);
> +	assert(ptr != (void *)-1);
> +
> +	if (seal) {
> +		ret = sys_mseal(ptr, size);
> +		assert(!ret);
> +	}
> +
> +	/* sealing doesn't take effect on RW memory. */
> +	ret = sys_madvise(ptr, size, MADV_DONTNEED);
> +	assert(!ret);
> +
> +	/* base seal still apply. */
> +	ret = sys_munmap(ptr, size);
> +	if (seal)
> +		assert(ret < 0);
> +	else
> +		assert(!ret);
> +}
> +
> +static void test_seal_discard_ro_anon_on_pkey(bool seal)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +	int ret;
> +	int pkey;
> +
> +	setup_single_address_rw_sealable(size, &ptr, seal);
> +	assert(ptr != (void *)-1);
> +
> +	pkey = sys_pkey_alloc(0, 0);
> +	assert(pkey > 0);
> +
> +	ret = sys_mprotect_pkey((void *)ptr, size, PROT_READ | PROT_WRITE, pkey);
> +	assert(!ret);
> +
> +	if (seal) {
> +		ret = sys_mseal(ptr, size);
> +		assert(!ret);
> +	}
> +
> +	/* sealing doesn't take effect if PKRU allow write. */
> +	set_pkey(pkey, 0);
> +	ret = sys_madvise(ptr, size, MADV_DONTNEED);
> +	assert(!ret);
> +
> +	/* sealing will take effect if PKRU deny write. */
> +	set_pkey(pkey, PKEY_DISABLE_WRITE);
> +	ret = sys_madvise(ptr, size, MADV_DONTNEED);
> +	if (seal)
> +		assert(ret < 0);
> +	else
> +		assert(!ret);
> +
> +	/* base seal still apply. */
> +	ret = sys_munmap(ptr, size);
> +	if (seal)
> +		assert(ret < 0);
> +	else
> +		assert(!ret);
> +}
> +
> +static void test_seal_discard_ro_anon_on_filebacked(bool seal)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +	int ret;
> +	int fd;
> +	unsigned long mapflags = MAP_PRIVATE;
> +
> +	if (seal)
> +		mapflags |= MAP_SEALABLE;
> +
> +	fd = memfd_create("test", 0);
> +	assert(fd > 0);
> +
> +	ret = fallocate(fd, 0, 0, size);
> +	assert(!ret);
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ, mapflags, fd, 0);
> +	assert(ptr != MAP_FAILED);
> +
> +	if (seal) {
> +		ret = sys_mseal(ptr, size);
> +		assert(!ret);
> +	}
> +
> +	/* sealing doesn't apply for file backed mapping. */
> +	ret = sys_madvise(ptr, size, MADV_DONTNEED);
> +	assert(!ret);
> +
> +	ret = sys_munmap(ptr, size);
> +	if (seal)
> +		assert(ret < 0);
> +	else
> +		assert(!ret);
> +	close(fd);
> +}
> +
> +static void test_seal_discard_ro_anon_on_shared(bool seal)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +	int ret;
> +	unsigned long mapflags = MAP_ANONYMOUS | MAP_SHARED;
> +
> +	if (seal)
> +		mapflags |= MAP_SEALABLE;
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ, mapflags, -1, 0);
> +	assert(ptr != (void *)-1);
> +
> +	if (seal) {
> +		ret = sys_mseal(ptr, size);
> +		assert(!ret);
> +	}
> +
> +	/* sealing doesn't apply for shared mapping. */
> +	ret = sys_madvise(ptr, size, MADV_DONTNEED);
> +	assert(!ret);
> +
> +	ret = sys_munmap(ptr, size);
> +	if (seal)
> +		assert(ret < 0);
> +	else
> +		assert(!ret);
> +}
> +
> +static void test_seal_discard_ro_anon_invalid_shared(bool seal)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +	int ret;
> +	int fd;
> +
> +	fd = open("/proc/self/maps", O_RDONLY);
> +	ptr = sys_mmap(NULL, size, PROT_READ, MAP_ANONYMOUS | MAP_PRIVATE, fd, 0);
> +	assert(ptr != (void *)-1);
> +
> +	if (seal) {
> +		ret = sys_mseal(ptr, size);
> +		assert(!ret);
> +	}
> +
> +	ret = sys_madvise(ptr, size, MADV_DONTNEED);
> +	assert(!ret);
> +
> +	ret = sys_munmap(ptr, size);
> +	assert(ret < 0);
> +	close(fd);
> +}
> +
> +static void test_seal_discard_ro_anon(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_single_address(ptr, size);
> +
> +	ret = sys_madvise(ptr, size, MADV_DONTNEED);
> +	if (seal)
> +		assert(ret < 0);
> +	else
> +		assert(!ret);
> +
> +	ret = sys_munmap(ptr, size);
> +	if (seal)
> +		assert(ret < 0);
> +	else
> +		assert(!ret);
> +}
> +
> +static void test_mmap_seal_discard_ro_anon(void)
> +{
> +	LOG_TEST_ENTER();
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +	unsigned long size = 4 * page_size;
> +	int ret;
> +
> +	ptr = sys_mmap(NULL, size, PROT_READ | PROT_WRITE | PROT_SEAL,
> +			MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
> +	assert(ptr != (void *)-1);
> +
> +	ret = sys_mprotect(ptr, size, PROT_READ);
> +	assert(!ret);
> +
> +	ret = sys_madvise(ptr, size, MADV_DONTNEED);
> +	assert(ret < 0);
> +
> +	ret = sys_munmap(ptr, size);
> +	assert(ret < 0);
> +}
> +
> +bool seal_support(void)
> +{
> +	int ret;
> +	void *ptr;
> +	unsigned long page_size = getpagesize();
> +
> +	ptr = sys_mmap(NULL, page_size, PROT_READ | PROT_SEAL, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
> +	if (ptr == (void *) -1)
> +		return false;
> +
> +	ret = sys_mseal(ptr, page_size);
> +	if (ret < 0)
> +		return false;
> +
> +	return true;
> +}
> +
> +bool pkey_supported(void)
> +{
> +	int pkey = sys_pkey_alloc(0, 0);
> +
> +	if (pkey > 0)
> +		return true;
> +	return false;
> +}
> +
> +int main(int argc, char **argv)
> +{

	ksft_print_header();
	if (test_seal())
		return ksft_exit_pass();
	ksft_set_plan(10);

> +	bool test_seal = seal_support();
> +
> +	if (!test_seal) {
> +		ksft_print_msg("sealing not supported (check CONFIG_64BIT)\n");
> +		return 0;
> +	}
> +
> +	test_seal_addseal();
> +
> +	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_invalid_input();
> +	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_discard_ro_anon(false);
> +	test_seal_discard_ro_anon(true);
> +	test_seal_discard_ro_anon_on_rw(false);
> +	test_seal_discard_ro_anon_on_rw(true);
> +	test_seal_discard_ro_anon_on_shared(false);
> +	test_seal_discard_ro_anon_on_shared(true);
> +	test_seal_discard_ro_anon_on_filebacked(false);
> +	test_seal_discard_ro_anon_on_filebacked(true);
> +	test_seal_mmap_overwrite_prot(false);
> +	test_seal_mmap_overwrite_prot(true);
> +	test_seal_mmap_expand(false);
> +	test_seal_mmap_expand(true);
> +	test_seal_mmap_shrink(false);
> +	test_seal_mmap_shrink(true);
> +
> +	test_seal_mmap_seal();
> +	test_seal_merge_and_split();
> +	test_seal_mmap_merge();
> +
> +	test_not_sealable();
> +	test_merge_sealable();
> +	test_mmap_fixed_change_to_sealable();
> +	test_mmap_fixed_change_to_not_sealable();
> +
> +	if (pkey_supported()) {
> +		test_seal_discard_ro_anon_on_pkey(false);
> +		test_seal_discard_ro_anon_on_pkey(true);
> +	} else
> +		ksft_print_msg("PKEY not supported, skip pkey related test\n");
> +
> +	ksft_print_msg("Done\n");
> +	return 0;
Rather ksft_finishsed();

> +}

-- 
BR,
Muhammad Usama Anjum