On Mon, Sep 02, 2019 at 12:29:29pm +0100, Cristian Marussi wrote:
> Add a simple fake_sigreturn testcase which builds a ucontext_t without
> the required fpsimd_context and place it onto the stack.
> Expects a SIGSEGV on test PASS.
>
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---
> v3 --> v4
> - fix commit
> - added signal.h
> - added test description
> ---
> .../testcases/fake_sigreturn_missing_fpsimd.c | 50 +++++++++++++++++++
> 1 file changed, 50 insertions(+)
> create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c
>
> diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c
> new file mode 100644
> index 000000000000..08ecd8073a1a
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c
> @@ -0,0 +1,50 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 ARM Limited
> + *
> + * Place a fake sigframe on the stack missing the mandatory FPSIMD
> + * record: on sigreturn Kernel must spot this attempt and the test
> + * case is expected to be terminated via SEGV.
> + */
> +
> +#include <stdio.h>
> +#include <signal.h>
> +#include <ucontext.h>
> +
> +#include "test_signals_utils.h"
> +#include "testcases.h"
> +
> +struct fake_sigframe sf;
> +
> +static int fake_sigreturn_missing_fpsimd_run(struct tdescr *td,
> + siginfo_t *si, ucontext_t *uc)
> +{
> + size_t resv_sz, offset;
> + struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
> +
> + /* just to fill the ucontext_t with something real */
> + if (!get_current_context(td, &sf.uc))
> + return 1;
> +
> + resv_sz = GET_SF_RESV_SIZE(sf);
> + head = get_header(head, FPSIMD_MAGIC, resv_sz, &offset);
> + if (head && resv_sz - offset >= HDR_SZ) {
> + fprintf(stderr, "Mangling template header. Spare space:%zd\n",
> + resv_sz - offset);
> + /* Just overwrite fpsmid_context */
> + write_terminator_record(head);
Strictly speaking, we may be throwing away more than just the
fpsimd_context record here.
But I think the test works nonetheless. fpsimd_context is the only
record that's mandatory in any case.
> +
> + ASSERT_BAD_CONTEXT(&sf.uc);
> + fake_sigreturn(&sf, sizeof(sf), 0);
> + }
> +
> + return 1;
> +}
> +
> +struct tdescr tde = {
> + .name = "FAKE_SIGRETURN_MISSING_FPSIMD",
> + .descr = "Triggers a sigreturn with a missing fpsimd_context",
> + .sig_ok = SIGSEGV,
> + .timeout = 3,
> + .run = fake_sigreturn_missing_fpsimd_run,
> +};
Assuming the comment I just posted on v3 of this patch makes sense to you,
Reviewed-by: Dave Martin <Dave.Martin@xxxxxxx>
