From 67203f3f2a63d429272f0c80451e5fcc469fdb46 Mon Sep 17 00:00:00 2001 From: Pedro Falcato Date: Wed, 7 Aug 2024 18:33:36 +0100 Subject: [PATCH] selftests/mm: add mseal test for no-discard madvise Add an mseal test for madvise() operations that aren't considered "discard" (e.g purely advisory ops such as MADV_RANDOM). [pedro.falcato@gmail.com: adjust the mseal test's plan] Link: https://lkml.kernel.org/r/20240807203724.2686144-1-pedro.falcato@gmail.com Link: https://lkml.kernel.org/r/20240807173336.2523757-3-pedro.falcato@gmail.com Signed-off-by: Pedro Falcato Tested-by: Jeff Xu Reviewed-by: Jeff Xu Cc: Kees Cook Cc: Liam R. Howlett Cc: Shuah Khan Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/mseal_test.c | 36 ++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/mseal_test.c b/tools/testing/selftests/mm/mseal_test.c index a818f010de47..7eec3f0152e3 100644 --- a/tools/testing/selftests/mm/mseal_test.c +++ b/tools/testing/selftests/mm/mseal_test.c @@ -1731,6 +1731,38 @@ static void test_seal_discard_ro_anon(bool seal) REPORT_TEST_PASS(); } +static void test_seal_madvise_nodiscard(bool seal) +{ + void *ptr; + unsigned long page_size = getpagesize(); + unsigned long size = 4 * page_size; + int ret; + + setup_single_address(size, &ptr); + FAIL_TEST_IF_FALSE(ptr != (void *)-1); + + if (seal) { + ret = seal_single_address(ptr, size); + FAIL_TEST_IF_FALSE(!ret); + } + + /* + * Test a random madvise flag like MADV_RANDOM that does not touch page + * contents (and thus should work for msealed VMAs). RANDOM also happens to + * share bits with other discard-ish flags like REMOVE. + */ + ret = sys_madvise(ptr, size, MADV_RANDOM); + FAIL_TEST_IF_FALSE(!ret); + + ret = sys_munmap(ptr, size); + if (seal) + FAIL_TEST_IF_FALSE(ret < 0); + else + FAIL_TEST_IF_FALSE(!ret); + + REPORT_TEST_PASS(); +} + int main(int argc, char **argv) { bool test_seal = seal_support(); @@ -1743,7 +1775,7 @@ int main(int argc, char **argv) if (!pkey_supported()) ksft_print_msg("PKEY not supported\n"); - ksft_set_plan(80); + ksft_set_plan(82); test_seal_addseal(); test_seal_unmapped_start(); @@ -1822,6 +1854,8 @@ int main(int argc, char **argv) test_seal_mremap_move_fixed_zero(true); test_seal_mremap_move_dontunmap_anyaddr(false); test_seal_mremap_move_dontunmap_anyaddr(true); + test_seal_madvise_nodiscard(false); + test_seal_madvise_nodiscard(true); test_seal_discard_ro_anon(false); test_seal_discard_ro_anon(true); test_seal_discard_ro_anon_on_rw(false); -- 2.25.1