On Thu, Aug 29, 2024 at 09:43:51PM GMT, jef...@chromium.org wrote:
> From: Jeff Xu <jef...@chromium.org>
>
> Add sealing test to cover mmap for
> Expand/shrink across vmas.
> Reuse the same address in !MAP_FIXED case.
>
> Signed-off-by: Jeff Xu <jef...@chromium.org>
> ---
> tools/testing/selftests/mm/mseal_test.c | 125 +++++++++++++++++++++++-
> 1 file changed, 124 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/mm/mseal_test.c
> b/tools/testing/selftests/mm/mseal_test.c
> index ae06c354220d..d83538039e76 100644
> --- a/tools/testing/selftests/mm/mseal_test.c
> +++ b/tools/testing/selftests/mm/mseal_test.c
> @@ -2222,6 +2222,122 @@ static void test_munmap_free_multiple_ranges(bool
> seal)
> REPORT_TEST_PASS();
> }
>
> +static void test_seal_mmap_expand_seal_middle(bool seal)
> +{
> + void *ptr;
> + unsigned long page_size = getpagesize();
> + unsigned long size = 12 * page_size;
> + int ret;
> + void *ret2;
> + int prot;
> +
> + setup_single_address(size, &ptr);
> + FAIL_TEST_IF_FALSE(ptr != (void *)-1);
> + /* ummap last 4 pages. */
> + ret = sys_munmap(ptr + 8 * page_size, 4 * page_size);
> + FAIL_TEST_IF_FALSE(!ret);
> +
> + size = get_vma_size(ptr, &prot);
> + FAIL_TEST_IF_FALSE(size == 8 * page_size);
> + FAIL_TEST_IF_FALSE(prot == 0x4);
> +
> + if (seal) {
> + ret = sys_mseal(ptr + 4 * page_size, 4 * page_size);
> + FAIL_TEST_IF_FALSE(!ret);
> + }
> +
> + /* use mmap to expand. */
> + ret2 = mmap(ptr, 12 * page_size, PROT_READ,
> + MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
This is not expansion, but overwriting. Expansion is allowed through an
adjacent mmap + mseal (which will merge the two VMAs).
> + if (seal) {
> + FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
> + FAIL_TEST_IF_FALSE(errno == EPERM);
> +
> + size = get_vma_size(ptr, &prot);
> + FAIL_TEST_IF_FALSE(size == 4 * page_size);
> + FAIL_TEST_IF_FALSE(prot == 0x4);
> +
> + size = get_vma_size(ptr + 4 * page_size, &prot);
> + FAIL_TEST_IF_FALSE(size == 4 * page_size);
> + FAIL_TEST_IF_FALSE(prot == 0x4);
> + } else
> + FAIL_TEST_IF_FALSE(ret2 == ptr);
> +
> + REPORT_TEST_PASS();
> +}
> +
> +static void test_seal_mmap_shrink_seal_middle(bool seal)
> +{
> + void *ptr;
> + unsigned long page_size = getpagesize();
> + unsigned long size = 12 * page_size;
> + int ret;
> + void *ret2;
> + int prot;
> +
> + setup_single_address(size, &ptr);
> + FAIL_TEST_IF_FALSE(ptr != (void *)-1);
> +
> + if (seal) {
> + ret = sys_mseal(ptr + 4 * page_size, 4 * page_size);
> + FAIL_TEST_IF_FALSE(!ret);
> + }
> +
> + /* use mmap to shrink. */
> + ret2 = mmap(ptr, 7 * page_size, PROT_READ,
> + MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
This is also a partial overwrite.
> + if (seal) {
> + FAIL_TEST_IF_FALSE(ret2 == MAP_FAILED);
> + FAIL_TEST_IF_FALSE(errno == EPERM);
> +
> + size = get_vma_size(ptr, &prot);
> + FAIL_TEST_IF_FALSE(size == 4 * page_size);
> + FAIL_TEST_IF_FALSE(prot == 0x4);
> +
> + size = get_vma_size(ptr + 4 * page_size, &prot);
> + FAIL_TEST_IF_FALSE(size == 4 * page_size);
> + FAIL_TEST_IF_FALSE(prot == 0x4);
> +
> + size = get_vma_size(ptr + 4 * page_size, &prot);
> + FAIL_TEST_IF_FALSE(size == 4 * page_size);
> + FAIL_TEST_IF_FALSE(prot == 0x4);
> + } else
> + FAIL_TEST_IF_FALSE(ret2 == ptr);
> +
> + REPORT_TEST_PASS();
> +}
> +
> +static void test_seal_mmap_reuse_addr(bool seal)
> +{
> + void *ptr;
> + unsigned long page_size = getpagesize();
> + unsigned long size = page_size;
> + int ret;
> + void *ret2;
> + int prot;
> +
> + setup_single_address(size, &ptr);
> + FAIL_TEST_IF_FALSE(ptr != (void *)-1);
> +
> + if (seal) {
> + ret = sys_mseal(ptr, size);
> + FAIL_TEST_IF_FALSE(!ret);
> + }
> +
> + /* use mmap to change protection. */
> + ret2 = mmap(ptr, size, PROT_NONE,
> + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
> +
This is also an overwrite. You're semantically testing the same thing, and
testing the same regions of code.
These 3 tests are all kind of the same thing.
--
Pedro
