On Thu, Jun 13, 2019 at 12:13:28PM +0100, Cristian Marussi wrote:
> Added a simple mangle testcase which messes with the ucontext_t
> from within the sig_handler, trying to toggle PSTATE state bits
> to switch the system between 32bit/64bit execution state.
> Expects SIGSEGV on test PASS.
Maybe say "compat_toggle" instead of "state_toggle" in the test name.
"state" is a bit of a generic term.
Once upon a time, the kernel didn't prohibit this toggle, which was a
"cool feature" before compat existed for real. I think this probably
got sorted before the initial arm64 port was upstreamed.
>
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---
> .../arm64/signal/testcases/.gitignore | 1 +
> .../mangle_pstate_invalid_state_toggle.c | 25 +++++++++++++++++++
> 2 files changed, 26 insertions(+)
> create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_state_toggle.c
>
> diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore
> index a609a08b744f..91f7aee4b666 100644
> --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore
> +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore
> @@ -1,3 +1,4 @@
> mangle_sp_misaligned
> mangle_pc_invalid
> mangle_pstate_invalid_daif_bits
> +mangle_pstate_invalid_state_toggle
> diff --git a/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_state_toggle.c b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_state_toggle.c
> new file mode 100644
> index 000000000000..971193e7501b
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_state_toggle.c
> @@ -0,0 +1,25 @@
> +/* 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 */
> + uc->uc_mcontext.pstate ^= PSR_MODE32_BIT;
As for other tests, is there a way to sanity-check that the SIGSEGV was
generated by sigreturn itself?
[...]
Cheers
---Dave
