On Mon, Sep 02, 2019 at 12:29:28pm +0100, Cristian Marussi wrote:
> Add a simple fake_sigreturn testcase which builds a ucontext_t with a
> badly sized terminator record and place it onto the stack.
> Expects a SIGSEGV on test PASS.
>
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---
> v3 --> v4
> - fix commit
> - add signal.h include
> - using new get_starting_head() helper
> - added test description
> ---
> .../fake_sigreturn_bad_size_for_magic0.c | 49 +++++++++++++++++++
> 1 file changed, 49 insertions(+)
> create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
>
> diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
> new file mode 100644
> index 000000000000..25017fe18214
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
> @@ -0,0 +1,49 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 ARM Limited
> + *
> + * Place a fake sigframe on the stack including a badly sized terminator
> + * record: on sigreturn Kernel must spot this attempt and the test case
> + * is expected to be terminated via SEGV.
> + */
> +
> +#include <signal.h>
> +#include <ucontext.h>
> +
> +#include "test_signals_utils.h"
> +#include "testcases.h"
> +
> +struct fake_sigframe sf;
> +
> +static int fake_sigreturn_bad_size_for_magic0_run(struct tdescr *td,
> + siginfo_t *si, ucontext_t *uc)
> +{
> + size_t resv_sz, need_sz;
> + struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
> +
> + /* 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);
> + /* at least HDR_SZ for the badly sized terminator. */
> + need_sz = HDR_SZ;
Nit: do we need the resv_sz and need_sz variables here?
> + head = get_starting_head(shead, need_sz, resv_sz, NULL);
> + if (head) {
Perhaps we could fail immediately rather than relying on timeout here?
Probably not a huge deal though.
> + head->magic = 0;
> + head->size = HDR_SZ;
> +
> + ASSERT_BAD_CONTEXT(&sf.uc);
> + fake_sigreturn(&sf, sizeof(sf), 0);
> + }
> +
> + return 1;
> +}
> +
> +struct tdescr tde = {
> + .name = "FAKE_SIGRETURN_BAD_SIZE_FOR_TERMINATOR",
> + .descr = "Trigger a sigreturn using non-zero size terminator",
> + .sig_ok = SIGSEGV,
> + .timeout = 3,
> + .run = fake_sigreturn_bad_size_for_magic0_run,
> +};
Either way,
Reviewed-by: Dave Martin <Dave.Martin@xxxxxxx>
