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[PATCH v2 3/4] selftests/mm: mseal_test add more tests for mmap

jeffxu@chromium.org posted 4 patches 1 year, 3 months ago
There is a newer version of this series
[PATCH v2 3/4] selftests/mm: mseal_test add more tests for mmap
Posted by jeffxu@chromium.org 1 year, 3 months ago 
From: Jeff Xu <jeffxu@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 <jeffxu@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);
+	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);
+	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);
+
+	FAIL_TEST_IF_FALSE(!(ret2 == MAP_FAILED));
+	FAIL_TEST_IF_FALSE(ret2 != ptr);
+
+	size = get_vma_size(ptr, &prot);
+	FAIL_TEST_IF_FALSE(size == page_size);
+	FAIL_TEST_IF_FALSE(prot == 0x4);
+
+	REPORT_TEST_PASS();
+}
+
 int main(int argc, char **argv)
 {
 	bool test_seal = seal_support();
@@ -2243,7 +2359,7 @@ int main(int argc, char **argv)
 	if (!get_vma_size_supported())
 		ksft_exit_skip("get_vma_size not supported\n");
 
-	ksft_set_plan(91);
+	ksft_set_plan(97);
 
 	test_seal_addseal();
 	test_seal_unmapped_start();
@@ -2357,5 +2473,12 @@ int main(int argc, char **argv)
 	test_munmap_free_multiple_ranges(false);
 	test_munmap_free_multiple_ranges(true);
 
+	test_seal_mmap_expand_seal_middle(false);
+	test_seal_mmap_expand_seal_middle(true);
+	test_seal_mmap_shrink_seal_middle(false);
+	test_seal_mmap_shrink_seal_middle(true);
+	test_seal_mmap_reuse_addr(false);
+	test_seal_mmap_reuse_addr(true);
+
 	ksft_finished();
 }
-- 
2.46.0.469.g59c65b2a67-goog
Re: [PATCH v2 3/4] selftests/mm: mseal_test add more tests for mmap
Posted by Pedro Falcato 1 year, 3 months ago 
On Thu, Aug 29, 2024 at 09:43:51PM GMT, jeffxu@chromium.org wrote:
> From: Jeff Xu <jeffxu@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 <jeffxu@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
Re: [PATCH v2 3/4] selftests/mm: mseal_test add more tests for mmap
Posted by Jeff Xu 1 year, 3 months ago 
Hi Pedro

On Fri, Aug 30, 2024 at 5:57 AM Pedro Falcato <pedro.falcato@gmail.com> wrote:
>
> On Thu, Aug 29, 2024 at 09:43:51PM GMT, jeffxu@chromium.org wrote:
> > From: Jeff Xu <jeffxu@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 <jeffxu@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).

The mmap is trying to expand the address range beginning from ptr
(size 8 * page_size) to 12 * page_size. This is overwrite + expansion.

>
> > +     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.
The mmap is trying to shrink the address range beginning from ptr
(size 12 * page_size) to 8 * page_size. This is overwrite + shrink.

>
> > +     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.

This is not overwriting. MAP_FIXED is not used.

-Jeff

> These 3 tests are all kind of the same thing.
>
> --
> Pedro

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