kselftest/arm64: Log signal code and address for unexpected signals

If we get an unexpected signal during a signal test log a bit more data to
aid diagnostics.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230620-arm64-selftest-log-wrong-signal-v1-1-3fe29bdaaf38@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: Copy whole EXTRA context

When copying the EXTRA context our calculation of the amount of data we
need to copy is incorrect, we only calculate the amount of data needed
within uc_mcontext.__reserved, not taking account of the fixed portion
of the context. Add in the offset of the reserved data so that we copy
everything we should.

This will only cause test failures in cases where the last context in the
EXTRA context is smaller than the missing data since we don't currently
validate any of the register data and all the buffers we copy into are
statically allocated so default to zero meaning that if we walk beyond the
end of what we copied we'll encounter what looks like a context with magic
and length both 0 which is a valid terminator record.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230201-arm64-kselftest-full-extra-v1-1-93741f32dd29@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: Enumerate SME2 in the signal test utility code

Support test cases for SME2 by adding it to the set of features that we
enumerate so test cases can check for it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-16-f2fa0aef982f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: Preserve any EXTRA_CONTEXT in handle_signal_copyctx()

When preserving the signal context for later verification by testcases
check for and include any EXTRA_CONTEXT block if enough space has been
provided.

Since the EXTRA_CONTEXT block includes a pointer to the start of the
additional data block we need to do at least some fixup on the copied
data. For simplicity in users we do this by extending the length of
the EXTRA_CONTEXT to include the following termination record, this
will cause users to see the extra data as part of the linked list of
contexts without needing any special handling. Care will be needed if
any specific tests for EXTRA_CONTEXT are added beyond the validation
done in ASSERT_GOOD_CONTEXT.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220829160703.874492-9-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: Validate signal ucontext in place

In handle_input_signal_copyctx() we use ASSERT_GOOD_CONTEXT() to validate
that the context we are saving meets expectations however we do this on
the saved copy rather than on the actual signal context passed in. This
breaks validation of EXTRA_CONTEXT since we attempt to validate the ABI
requirement that the additional space supplied is immediately after the
termination record in the standard context which will not be the case
after it has been copied to another location.

Fix this by doing the validation before we copy. Note that nothing actually
looks inside the EXTRA_CONTEXT at present.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220829160703.874492-3-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: signal: Add SME signal handling tests

Add test cases for the SME signal handing ABI patterned off the SVE tests.
Due to the small size of the tests and the differences in ABI (especially
around needing to account for both streaming SVE and ZA) there is some code
duplication here.

We currently cover:
- Reporting of the vector length.
- Lack of support for changing vector length.
- Presence and size of register state for streaming SVE and ZA.

As with the SVE tests we do not yet have any validation of register
contents.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-36-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: signal: Allow tests to be incompatible with features

Some features may invalidate some tests, for example by supporting an
operation which would trap otherwise. Allow tests to list features that
they are incompatible with so we can cover the case where a signal will
be generated without disruption on systems where that won't happen.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220207152109.197566-6-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

kselftest/arm64: Allow signal tests to trigger from a function

Currently we have the facility to specify custom code to trigger a signal
but none of the tests use it and for some reason the framework requires us
to also specify a signal to send as a trigger in order to make use of a
custom trigger. This doesn't seem to make much sense, instead allow the
use of a custom trigger function without specifying a signal to inject.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211210184133.320748-6-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: signal: Skip tests if required features are missing

During initialization of a signal testcase, features declared as required
are properly checked against the running system but no action is then taken
to effectively skip such a testcase.

Fix core signals test logic to abort initialization and report such a
testcase as skipped to the KSelfTest framework.

Fixes: f96bf4340316 ("kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210920121228.35368-1-cristian.marussi@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: signal: Add SVE to the set of features we can check for

Allow testcases for SVE signal handling to flag the dependency and be
skipped on systems without SVE support.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210819134245.13935-2-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest: arm64: add helper get_current_context

Introduce a new common utility function get_current_context() which can be
used to grab a ucontext without the help of libc, and also to detect if
such ucontext has been successfully used by placing it on the stack as a
fake sigframe.

Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest: arm64: extend test_init functionalities

Extend signal testing framework to allow the definition of a custom per
test initialization function to be run at the end of the common test_init
after test setup phase has completed and before test-run routine.

This custom per-test initialization function also enables the test writer
to decide on its own when forcibly skip the test itself using standard KSFT
mechanism.

Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils

Add some arm64/signal specific boilerplate and utility code to help
further testcases' development.

Introduce also one simple testcase mangle_pstate_invalid_compat_toggle
and some related helpers: it is a simple mangle testcase which messes
with the ucontext_t from within the signal handler, trying to toggle
PSTATE state bits to switch the system between 32bit/64bit execution
state. Expects SIGSEGV on test PASS.

Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>