selftests: kselftest_harness: save full exit code in metadata

Instead of tracking passed = 0/1 rename the field to exit_code
and invert the values so that they match the KSFT_* exit codes.
This will allow us to fold SKIP / XFAIL into the same value.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests/landlock: Test ptrace as much as possible with Yama

Update ptrace tests according to all potential Yama security policies.
This is required to make such tests pass even if Yama is enabled.

Tests are not skipped but they now check both Landlock and Yama boundary
restrictions at run time to keep a maximum test coverage (i.e. positive
and negative testing).

Signed-off-by: Jeff Xu <jeffxu@google.com>
Link: https://lore.kernel.org/r/20230114020306.1407195-2-jeffxu@google.com
Cc: stable@vger.kernel.org
[mic: Add curly braces around EXPECT_EQ() to make it build, and improve
commit message]
Co-developed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Mickaël Salaün <mic@digikod.net>

selftests/landlock: Format with clang-format

Let's follow a consistent and documented coding style. Everything may
not be to our liking but it is better than tacit knowledge. Moreover,
this will help maintain style consistency between different developers.

This contains only whitespace changes.

Automatically formatted with:
clang-format-14 -i tools/testing/selftests/landlock/*.[ch]

Link: https://lore.kernel.org/r/20220506160513.523257-6-mic@digikod.net
Cc: stable@vger.kernel.org
[mic: Update style according to
https://lore.kernel.org/r/02494cb8-2aa5-1769-f28d-d7206f284e5a@digikod.net]
Signed-off-by: Mickaël Salaün <mic@digikod.net>

selftests/landlock: Add clang-format exceptions

In preparation to a following commit, add clang-format on and
clang-format off stanzas around constant definitions and the TEST_F_FORK
macro. This enables to keep aligned values, which is much more readable
than packed definitions.

Add other clang-format exceptions for FIXTURE() and
FIXTURE_VARIANT_ADD() declarations to force space before open brace,
which is reported by checkpatch.pl .

Link: https://lore.kernel.org/r/20220506160513.523257-4-mic@digikod.net
Cc: stable@vger.kernel.org
Signed-off-by: Mickaël Salaün <mic@digikod.net>

selftests/landlock: Add user space tests

Test all Landlock system calls, ptrace hooks semantic and filesystem
access-control with multiple layouts.

Test coverage for security/landlock/ is 93.6% of lines. The code not
covered only deals with internal kernel errors (e.g. memory allocation)
and race conditions.

Cc: James Morris <jmorris@namei.org>
Cc: Jann Horn <jannh@google.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Vincent Dagonneau <vincent.dagonneau@ssi.gouv.fr>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210422154123.13086-11-mic@digikod.net
Signed-off-by: James Morris <jamorris@linux.microsoft.com>