Re: [PATCH v3 04/11] kselftest: arm64: mangle_pstate_invalid_mode_el

From: Dave Martin <Dave.Martin@arm.com>
To: Cristian Marussi <cristian.marussi@arm.com>
Cc: linux-kselftest@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, shuah@kernel.org,
	andreyknvl@google.com
Subject: Re: [PATCH v3 04/11] kselftest: arm64: mangle_pstate_invalid_mode_el
Date: Tue, 13 Aug 2019 17:24:51 +0100	[thread overview]
Message-ID: <20190813162451.GB10425@arm.com> (raw)
In-Reply-To: <20190802170300.20662-5-cristian.marussi@arm.com>

On Fri, Aug 02, 2019 at 06:02:53PM +0100, Cristian Marussi wrote:
> Added 3 simple mangle testcases that mess with the ucontext_t

Add

> from within the sig_handler, trying to toggle PSTATE mode bits to

signal handler

> trick the system into switching to EL1/EL2/EL3. Expects SIGSEGV
> on test PASS.
> 
> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> ---
>  .../arm64/signal/testcases/.gitignore         |  3 ++
>  .../mangle_pstate_invalid_mode_el1.c          | 29 +++++++++++++++++++
>  .../mangle_pstate_invalid_mode_el2.c          | 29 +++++++++++++++++++
>  .../mangle_pstate_invalid_mode_el3.c          | 29 +++++++++++++++++++
>  4 files changed, 90 insertions(+)
>  create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el1.c
>  create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el2.c
>  create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el3.c
> 
> diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore
> index 8a0a29f0cc2a..226bb179b673 100644
> --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore
> +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore
> @@ -1,2 +1,5 @@
>  mangle_pstate_invalid_compat_toggle
>  mangle_pstate_invalid_daif_bits
> +mangle_pstate_invalid_mode_el1
> +mangle_pstate_invalid_mode_el2
> +mangle_pstate_invalid_mode_el3

What about having

	!*.[ch]
	mangle_*

rather than having to update .gitignore to list every test executable?

> diff --git a/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el1.c b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el1.c
> new file mode 100644
> index 000000000000..07aed7624383
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_mode_el1.c
> @@ -0,0 +1,29 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright (C) 2019 ARM Limited */
> +
> +#include "test_signals_utils.h"
> +#include "testcases.h"
> +
> +static int mangle_invalid_pstate_run(struct tdescr *td, siginfo_t *si,
> +				     ucontext_t *uc)
> +{
> +	ASSERT_GOOD_CONTEXT(uc);
> +
> +	/*
> +	 * This config should trigger a SIGSEGV by Kernel
> +	 * when checking valid_user_regs()
> +	 */
> +	uc->uc_mcontext.pstate &= ~PSR_MODE_MASK;
> +	uc->uc_mcontext.pstate |= PSR_MODE_EL1t;
> +
> +	return 1;
> +}
> +
> +struct tdescr tde = {
> +		.sanity_disabled = true,
> +		.name = "MANGLE_PSTATE_INVALID_MODE_EL1t",
> +		.descr = "Mangling uc_mcontext with INVALID MODE EL1t",
> +		.sig_trig = SIGUSR1,
> +		.sig_ok = SIGSEGV,
> +		.run = mangle_invalid_pstate_run,
> +};

These tests seem identical except for the EL number.
Can we macro-ise them?

mangle_pstate_invalid_mode_el1.c could become

--8<--

#include "mangle_pstate_invalid_mode.h"

DEFINE_TESTCASE_MANGLE_PSTATE_INVALID_MODE(1)

-->8--

(for example).

[...]

Cheers
---Dave