On Mon, Sep 02, 2019 at 12:29:32pm +0100, Cristian Marussi wrote:
> Add a simple fake_sigreturn testcase which places a valid sigframe on a
> non-16 bytes aligned SP. Expects a SIGSEGV on test PASS.
>
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---
> v3 --> v4
> - fix commit
> - use new fake_sigreturn misalig_bytes params
> - removed TODO
> - added test description
> ---
> .../testcases/fake_sigreturn_misaligned_sp.c | 37 +++++++++++++++++++
> 1 file changed, 37 insertions(+)
> create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c
>
> diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c
> new file mode 100644
> index 000000000000..1e089e66f9f3
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c
> @@ -0,0 +1,37 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 ARM Limited
> + *
> + * Place a fake sigframe on the stack at a misaligned SP: 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_misaligned_run(struct tdescr *td,
> + siginfo_t *si, ucontext_t *uc)
> +{
> + /* just to fill the ucontext_t with something real */
> + if (!get_current_context(td, &sf.uc))
> + return 1;
> +
> + /* Forcing sigframe on misaligned SP (16 + 3) */
> + fake_sigreturn(&sf, sizeof(sf), 3);
Can we add tests on the TODO list for other misalignments?
a) 4 (i.e., __alignof__(struct _aarch64_ctx))
b) 8 (i.e., sizeof(struct _aarch64_ctx))
This may help catch potential wrong-bitmask bugs in the kernel when
checking the alignment. Similarly to my suggestion on patch 10, these
can go on the TODO list and added later (probably macro-ised).
For now, let's get this series settled as-is -- so, after responding to
nits:
Reviewed-by: Dave Martin <Dave.Martin@xxxxxxx>
