Commit d5433ce8 authored by Peter Xu's avatar Peter Xu Committed by Andrew Morton
Browse files

selftests/mm: UFFDIO_API test 

Add one simple test for UFFDIO_API.  With that, I also added a bunch of
small but handy helpers along the way.

Link: https://lkml.kernel.org/r/20230412164257.328375-1-peterx@redhat.com


Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 78391f64

tools/testing/selftests/mm/uffd-unit-tests.c

+108 −1
Original line number Diff line number Diff line
@@ -9,9 +9,116 @@ 


#ifdef __NR_userfaultfd



static void uffd_test_report(void)

{

	printf("Userfaults unit tests: pass=%u, skip=%u, fail=%u (total=%u)\n",

	       ksft_get_pass_cnt(),

	       ksft_get_xskip_cnt(),

	       ksft_get_fail_cnt(),

	       ksft_test_num());

}



static void uffd_test_pass(void)

{

	printf("done\n");

	ksft_inc_pass_cnt();

}



#define  uffd_test_start(...)  do {		\

		printf("Testing ");		\

		printf(__VA_ARGS__);		\

		printf("... ");			\

		fflush(stdout);			\

	} while (0)



#define  uffd_test_fail(...)  do {		\

		printf("failed [reason: ");	\

		printf(__VA_ARGS__);		\

		printf("]\n");			\

		ksft_inc_fail_cnt();		\

	} while (0)



#define  uffd_test_skip(...)  do {		\

		printf("skipped [reason: ");	\

		printf(__VA_ARGS__);		\

		printf("]\n");			\

		ksft_inc_xskip_cnt();		\

	} while (0)



/*

 * Returns 1 if specific userfaultfd supported, 0 otherwise.  Note, we'll

 * return 1 even if some test failed as long as uffd supported, because in

 * that case we still want to proceed with the rest uffd unit tests.

 */

static int test_uffd_api(bool use_dev)

{

	struct uffdio_api uffdio_api;

	int uffd;



	uffd_test_start("UFFDIO_API (with %s)",

			use_dev ? "/dev/userfaultfd" : "syscall");



	if (use_dev)

		uffd = uffd_open_dev(UFFD_FLAGS);

	else

		uffd = uffd_open_sys(UFFD_FLAGS);

	if (uffd < 0) {

		uffd_test_skip("cannot open userfaultfd handle");

		return 0;

	}



	/* Test wrong UFFD_API */

	uffdio_api.api = 0xab;

	uffdio_api.features = 0;

	if (ioctl(uffd, UFFDIO_API, &uffdio_api) == 0) {

		uffd_test_fail("UFFDIO_API should fail with wrong api but didn't");

		goto out;

	}



	/* Test wrong feature bit */

	uffdio_api.api = UFFD_API;

	uffdio_api.features = BIT_ULL(63);

	if (ioctl(uffd, UFFDIO_API, &uffdio_api) == 0) {

		uffd_test_fail("UFFDIO_API should fail with wrong feature but didn't");

		goto out;

	}



	/* Test normal UFFDIO_API */

	uffdio_api.api = UFFD_API;

	uffdio_api.features = 0;

	if (ioctl(uffd, UFFDIO_API, &uffdio_api)) {

		uffd_test_fail("UFFDIO_API should succeed but failed");

		goto out;

	}



	/* Test double requests of UFFDIO_API with a random feature set */

	uffdio_api.features = BIT_ULL(0);

	if (ioctl(uffd, UFFDIO_API, &uffdio_api) == 0) {

		uffd_test_fail("UFFDIO_API should reject initialized uffd");

		goto out;

	}



	uffd_test_pass();

out:

	close(uffd);

	/* We have a valid uffd handle */

	return 1;

}



int main(int argc, char *argv[])

{

	return KSFT_PASS;

	int has_uffd;



	has_uffd = test_uffd_api(false);

	has_uffd |= test_uffd_api(true);



	if (!has_uffd) {

		printf("Userfaultfd not supported or unprivileged, skip all tests\n");

		exit(KSFT_SKIP);

	}

	uffd_test_report();



	return ksft_get_fail_cnt() ? KSFT_FAIL : KSFT_PASS;

}



#else /* __NR_userfaultfd */