On 02/08/2019 18:03, Cristian Marussi wrote:
> Added a simple fake_sigreturn testcase which places a valid
> sigframe on a non-16 bytes aligned SP.
> fake_sigretrun() helper function has been patched accordingly
> to support placing a sigframe on a non-16 bytes aligned address.
> Expects a SIGSEGV on test PASS.
>
> Adds also a test TODO lists holding some further test ideas.
>
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---
> Re-added this text after fixing the forced misaglinment procedure in
> fake_sigreturn() itself: require a ZERO alignment and you'll get
> your sigframe placed on a misaligned SP (2-bytes off the 16-align)
> ---
> .../testing/selftests/arm64/signal/signals.S | 21 +++++++++----
> .../arm64/signal/testcases/TODO.readme | 8 +++++
> .../testcases/fake_sigreturn_misaligned_sp.c | 30 +++++++++++++++++++
> 3 files changed, 53 insertions(+), 6 deletions(-)
> create mode 100644 tools/testing/selftests/arm64/signal/testcases/TODO.readme
> create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c
>
When this test was re-added in V3, the related .gitignore was missed.
It will go in V4
Cheers
Cristian
> diff --git a/tools/testing/selftests/arm64/signal/signals.S b/tools/testing/selftests/arm64/signal/signals.S
> index 6262b877400b..2099871176ed 100644
> --- a/tools/testing/selftests/arm64/signal/signals.S
> +++ b/tools/testing/selftests/arm64/signal/signals.S
> @@ -13,19 +13,28 @@ call_fmt:
>
> .globl fake_sigreturn
>
> -/* fake_sigreturn x0:&sigframe, x1:sigframe_size, x2:alignment_SP */
> +/* fake_sigreturn x0:&sigframe, x1:sigframe_sz, x2:align */
> fake_sigreturn:
> - mov x20, x0
> - mov x21, x1
> - mov x22, x2
> - mov x23, sp
>
> - /* create space on the stack for fake sigframe..."x22"-aligned */
> + /* Save args and decide which aligment to enforce */
> + mov x23, sp
> + mov x20, x0
> + mov x21, x1
> + /* x22 and x24 used for forcing alignment or misalignment */
> + mov x22, x2
> + mov x24, #0
> + cbnz x22, 1f
> + mov x22, #16
> + mov x24, #2
> +
> +1: /* create space on the stack for fake sigframe..."x22"-aligned */
> mov x0, #0
> add x0, x21, x22
> sub x22, x22, #1
> bic x0, x0, x22
> sub x23, x23, x0
> + /* force misaligned by x24 bytes if required alignment was zero */
> + add x23, x23, x24
>
> ldr x0, =call_fmt
> mov x1, x21
> diff --git a/tools/testing/selftests/arm64/signal/testcases/TODO.readme b/tools/testing/selftests/arm64/signal/testcases/TODO.readme
> new file mode 100644
> index 000000000000..5c949492e7ab
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/TODO.readme
> @@ -0,0 +1,8 @@
> +Some more possible ideas for signals tests:
> +
> +- fake_sigreturn_unmapped_sp
> +- fake_sigreturn_kernelspace_sp
> +- fake_sigreturn_sve_bad_extra_context
> +- mangle_sve_invalid_extra_context
> +- mangle_pstate_invalid_el for H modes (+ macroization ?)
> +- fake_sigreturn_overflow_reserved
> 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..3ee8c500c7d1
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c
> @@ -0,0 +1,30 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright (C) 2019 ARM Limited */
> +
> +#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 (=!16) SP */
> + fake_sigreturn(&sf, sizeof(sf), 0);
> +
> + return 1;
> +}
> +
> +struct tdescr tde = {
> + .name = "FAKE_SIGRETURN_MISALIGNED_SP",
> + .descr = "Triggers a fake sigreturn with a misaligned sigframe on SP",
> + .sig_ok = SIGSEGV,
> + .timeout = 3,
> + .run = fake_sigreturn_misaligned_run,
> +};
>
