Commit 4a8f021b authored by Axel Rasmussen's avatar Axel Rasmussen Committed by Linus Torvalds
Browse files

userfaultfd/selftests: exercise minor fault handling shmem support 

Enable test_uffdio_minor for test_type == TEST_SHMEM, and modify the test
slightly to pass in / check for the right feature flags.

Link: https://lkml.kernel.org/r/20210503180737.2487560-11-axelrasmussen@google.com


Signed-off-by: default avatarAxel Rasmussen <axelrasmussen@google.com>
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Wang Qing <wangqing@vivo.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8ba6e864

tools/testing/selftests/vm/userfaultfd.c

+25 −4
Original line number Diff line number Diff line
@@ -474,6 +474,7 @@ static void wp_range(int ufd, __u64 start, __u64 len, bool wp) 
static void continue_range(int ufd, __u64 start, __u64 len)

{

	struct uffdio_continue req;

	int ret;



	req.range.start = start;

	req.range.len = len;
@@ -482,6 +483,17 @@ static void continue_range(int ufd, __u64 start, __u64 len) 
	if (ioctl(ufd, UFFDIO_CONTINUE, &req))

		err("UFFDIO_CONTINUE failed for address 0x%" PRIx64,

		    (uint64_t)start);



	/*

	 * Error handling within the kernel for continue is subtly different

	 * from copy or zeropage, so it may be a source of bugs. Trigger an

	 * error (-EEXIST) on purpose, to verify doing so doesn't cause a BUG.

	 */

	req.mapped = 0;

	ret = ioctl(ufd, UFFDIO_CONTINUE, &req);

	if (ret >= 0 || req.mapped != -EEXIST)

		err("failed to exercise UFFDIO_CONTINUE error handling, ret=%d, mapped=%" PRId64,

		    ret, (int64_t) req.mapped);

}



static void *locking_thread(void *arg)
@@ -1182,7 +1194,7 @@ static int userfaultfd_minor_test(void) 
	void *expected_page;

	char c;

	struct uffd_stats stats = { 0 };

	uint64_t features = UFFD_FEATURE_MINOR_HUGETLBFS;

	uint64_t req_features, features_out;



	if (!test_uffdio_minor)

		return 0;
@@ -1190,9 +1202,17 @@ static int userfaultfd_minor_test(void) 
	printf("testing minor faults: ");

	fflush(stdout);



	uffd_test_ctx_init_ext(&features);

	/* If kernel reports the feature isn't supported, skip the test. */

	if (!(features & UFFD_FEATURE_MINOR_HUGETLBFS)) {

	if (test_type == TEST_HUGETLB)

		req_features = UFFD_FEATURE_MINOR_HUGETLBFS;

	else if (test_type == TEST_SHMEM)

		req_features = UFFD_FEATURE_MINOR_SHMEM;

	else

		return 1;



	features_out = req_features;

	uffd_test_ctx_init_ext(&features_out);

	/* If kernel reports required features aren't supported, skip test. */

	if ((features_out & req_features) != req_features) {

		printf("skipping test due to lack of feature support\n");

		fflush(stdout);

		return 0;
@@ -1575,6 +1595,7 @@ static void set_test_type(const char *type) 
		map_shared = true;

		test_type = TEST_SHMEM;

		uffd_test_ops = &shmem_uffd_test_ops;

		test_uffdio_minor = true;

	} else {

		err("Unknown test type: %s", type);

	}