Verify that a mapping created with MAP_DROPPABLE cannot be locked via mlock(), and that it will not be locked if it's created after mlockall(MCL_FUTURE).
Signed-off-by: Anthony Yznaga <[email protected]> --- tools/testing/selftests/mm/mlock2-tests.c | 78 ++++++++++++++++++++--- 1 file changed, 69 insertions(+), 9 deletions(-) diff --git a/tools/testing/selftests/mm/mlock2-tests.c b/tools/testing/selftests/mm/mlock2-tests.c index b474f2b20def..b5790e717dd6 100644 --- a/tools/testing/selftests/mm/mlock2-tests.c +++ b/tools/testing/selftests/mm/mlock2-tests.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #define _GNU_SOURCE #include <sys/mman.h> +#include <linux/mman.h> #include <stdint.h> #include <unistd.h> #include <string.h> @@ -163,14 +164,17 @@ static int lock_check(unsigned long addr) return (vma_rss == vma_size); } -static int unlock_lock_check(char *map) +static int unlock_lock_check(char *map, bool mlock_supported) { - if (is_vmflag_set((unsigned long)map, LOCKED)) { + if (!is_vmflag_set((unsigned long)map, LOCKED)) + return 0; + + if (mlock_supported) ksft_print_msg("VMA flag %s is present on page 1 after unlock\n", LOCKED); - return 1; - } + else + ksft_print_msg("VMA flag %s is present on an unsupported VMA\n", LOCKED); - return 0; + return 1; } static void test_mlock_lock(void) @@ -196,7 +200,7 @@ static void test_mlock_lock(void) ksft_exit_fail_msg("munlock(): %s\n", strerror(errno)); } - ksft_test_result(!unlock_lock_check(map), "%s: Unlocked\n", __func__); + ksft_test_result(!unlock_lock_check(map, true), "%s: Unlocked\n", __func__); munmap(map, 2 * page_size); } @@ -296,7 +300,7 @@ static void test_munlockall0(void) ksft_exit_fail_msg("munlockall(): %s\n", strerror(errno)); } - ksft_test_result(!unlock_lock_check(map), "%s: No locked memory\n", __func__); + ksft_test_result(!unlock_lock_check(map, true), "%s: No locked memory\n", __func__); munmap(map, 2 * page_size); } @@ -336,7 +340,61 @@ static void test_munlockall1(void) ksft_exit_fail_msg("munlockall() %s\n", strerror(errno)); } - ksft_test_result(!unlock_lock_check(map), "%s: No locked memory\n", __func__); + ksft_test_result(!unlock_lock_check(map, true), "%s: No locked memory\n", __func__); + munmap(map, 2 * page_size); +} + +/* + * Droppable memory should not be lockable. + */ +static void test_mlock_droppable(void) +{ + char *map; + unsigned long page_size = getpagesize(); + + /* + * Ensure MCL_FUTURE is not set. + */ + if (mlockall(MCL_CURRENT)) + ksft_exit_fail_msg("mlockall(MCL_CURRENT): %s\n", strerror(errno)); + if (munlockall()) + ksft_exit_fail_msg("munlockall() %s\n", strerror(errno)); + + map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_DROPPABLE, -1, 0); + if (map == MAP_FAILED) + ksft_exit_fail_msg("mmap error: %s", strerror(errno)); + + if (mlock2_(map, 2 * page_size, 0)) { + munmap(map, 2 * page_size); + ksft_exit_fail_msg("mlock2(0): %s\n", strerror(errno)); + } + + ksft_test_result(!unlock_lock_check(map, false), "%s: droppable memory not locked\n", + __func__); + + munmap(map, 2 * page_size); +} + +static void test_mlockall_future_droppable(void) +{ + char *map; + unsigned long page_size = getpagesize(); + + if (mlockall(MCL_CURRENT | MCL_FUTURE)) + ksft_exit_fail_msg("mlockall(MCL_CURRENT | MCL_FUTURE): %s\n", strerror(errno)); + + map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_DROPPABLE, -1, 0); + + ksft_test_result(!unlock_lock_check(map, false), "%s: droppable memory not locked\n", + __func__); + + if (munlockall()) { + munmap(map, 2 * page_size); + ksft_exit_fail_msg("munlockall() %s\n", strerror(errno)); + } + munmap(map, 2 * page_size); } @@ -442,7 +500,7 @@ int main(int argc, char **argv) munmap(map, size); - ksft_set_plan(13); + ksft_set_plan(15); test_mlock_lock(); test_mlock_onfault(); @@ -451,6 +509,8 @@ int main(int argc, char **argv) test_lock_onfault_of_present(); test_vma_management(true); test_mlockall(); + test_mlock_droppable(); + test_mlockall_future_droppable(); ksft_finished(); } -- 2.47.3
