On 4/10/26 01:49, Anthony Yznaga wrote:
> For configs that support MAP_DROPPABLE 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]>
> ---
[...]
> +
> +#ifdef MAP_DROPPABLE
> +/*
> + * Droppable memory should not be lockable.
> + */
Single-line comment.
> +static void test_mlock_droppable(void)
> +{
> + char *map;
> + unsigned long page_size = getpagesize();
We could store that in a static global and query it once during main().
Feel free to keep it as is.
> +
> + /*
> + * Ensure MCL_FUTURE is not set.
> + */
Dito.
> + if (munlockall()) {
> + ksft_test_result_fail("munlockall() %s\n", strerror(errno));
> + return;
> + }
> +
> + map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
> + MAP_ANONYMOUS | MAP_DROPPABLE, -1, 0);
> + if (map == MAP_FAILED) {
> + if (errno == EOPNOTSUPP)
> + ksft_test_result_skip("%s: MAP_DROPPABLE not
> supported\n", __func__);
> + else
> + ksft_test_result_fail("mmap error: %s\n",
> strerror(errno));
> + return;
> + }
> +
> + if (mlock2_(map, 2 * page_size, 0))
Weird, is "mlock2_" actually correct? (not "mlock2") ?
> + ksft_test_result_fail("mlock2(0): %s\n", strerror(errno));
> + else
> + 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_test_result_fail("mlockall(MCL_CURRENT | MCL_FUTURE):
> %s\n", strerror(errno));
> + return;
> + }
> +
> + map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
> + MAP_ANONYMOUS | MAP_DROPPABLE, -1, 0);
> +
> + if (map == MAP_FAILED) {
> + if (errno == EOPNOTSUPP)
> + ksft_test_result_skip("%s: MAP_DROPPABLE not
> supported\n", __func__);
> + else
> + ksft_test_result_fail("mmap error: %s\n",
> strerror(errno));
> + munlockall();
> + return;
> + }
> +
> + ksft_test_result(!unlock_lock_check(map, false), "%s: droppable memory
> not locked\n",
> + __func__);
> +
> + munlockall();
> munmap(map, 2 * page_size);
> }
> +#else
> +static void test_mlock_droppable(void)
> +{
> + ksft_test_result_skip("%s: MAP_DROPPABLE not supported\n", __func__);
> +}
> +
> +static void test_mlockall_future_droppable(void)
> +{
> + ksft_test_result_skip("%s: MAP_DROPPABLE not supported\n", __func__);
> +}
> +#endif /* MAP_DROPPABLE */
>
Why not a above a
#ifndef MAP_DROPPABLE
#define MAP_DROPPABLE 0x08
#endif
instead?
> static void test_vma_management(bool call_mlock)
> {
> @@ -442,7 +522,7 @@ 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 +531,8 @@ 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();
> }
Feel free to add
Acked-by: David Hildenbrand (Arm) <[email protected]>
--
Cheers,
David
