kselftest/arm64: Handle FPMR context in generic signal frame parser

Teach the generic signal frame parsing code about the newly added FPMR
frame, avoiding warnings every time one is generated.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240306-arm64-2023-dpisa-v5-7-c568edc8ed7f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: Teach the generic signal context validation about ZT

Add ZT to the set of signal contexts that the shared code understands and
validates the form of.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-17-f2fa0aef982f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: Include larger SVE and SME VLs in signal tests

Now that the core utilities for signal testing support handling data in
EXTRA_CONTEXT blocks we can test larger SVE and SME VLs which spill over
the limits in the base signal context. This is done by defining storage
for the context as a union with a ucontext_t and a buffer together with
some helpers for getting relevant sizes and offsets like we do for
fake_sigframe, this isn't the most lovely code ever but is fairly
straightforward to implement and much less invasive to the somewhat
unclear and indistinct layers of abstraction in the signal handling test
code.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220829160703.874492-11-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: Remove unneeded protype for validate_extra_context()

Nothing outside testcases.c should need to use validate_extra_context(),
remove the prototype to ensure nothing does.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220829160703.874492-6-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest/arm64: signal: Handle ZA signal context in core code

As part of the generic code for signal handling test cases we parse all
signal frames to make sure they have at least the basic form we expect
and that there are no unexpected frames present in the signal context.
Add coverage of the ZA signal frame to this code.

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/20220419112247.711548-34-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

kselftest: arm64: fake_sigreturn_bad_magic

Add a simple fake_sigreturn testcase which builds a ucontext_t with a bad
magic header and place it onto the stack. Expects a SIGSEGV on test PASS.

Introduce a common utility assembly trampoline function to invoke a
sigreturn while placing the provided sigframe at wanted alignment and
also an helper to make space when needed inside the sigframe reserved
area.

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>