On Mon, Sep 02, 2019 at 12:29:24pm +0100, Cristian Marussi wrote:
> Add a simple mangle testcase which messes with the ucontext_t from within
> the signal handler, trying to set PSTATE DAIF bits to an invalid value
> (masking everything). Expects SIGSEGV on test PASS.
>
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
Reviewed-by: Dave Martin <Dave.Martin@xxxxxxx>
> ---
> v3 --> v4
> - fixed commit message
> - added testcase comment description
> ---
> .../mangle_pstate_invalid_daif_bits.c | 35 +++++++++++++++++++
> 1 file changed, 35 insertions(+)
> create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c
>
> diff --git a/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c
> new file mode 100644
> index 000000000000..434b82597007
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c
> @@ -0,0 +1,35 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 ARM Limited
> + *
> + * Try to mangle the ucontext from inside a signal handler, mangling the
> + * DAIF bits in an illegal manner: this attempt must be spotted by Kernel
> + * and the test case is expected to be terminated via SEGV.
> + *
> + */
> +
> +#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 it checks
> + * the sigframe consistency in valid_user_regs() routine.
> + */
> + uc->uc_mcontext.pstate |= PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT;
> +
> + return 1;
> +}
> +
> +struct tdescr tde = {
> + .sanity_disabled = true,
> + .name = "MANGLE_PSTATE_INVALID_DAIF_BITS",
> + .descr = "Mangling uc_mcontext with INVALID DAIF_BITS",
> + .sig_trig = SIGUSR1,
> + .sig_ok = SIGSEGV,
> + .run = mangle_invalid_pstate_run,
> +};
> --
> 2.17.1
>
>
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