On Fri, Aug 02, 2019 at 06:02:56PM +0100, Cristian Marussi wrote:
> Added a simple fake_sigreturn testcase which builds a ucontext_t
Add
> with a badly sized magic0 header and place it onto the stack.
I usually call a record with magic number 0 a "terminator record".
> Expects a SIGSEGV on test PASS.
>
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---
> .../arm64/signal/testcases/.gitignore | 1 +
> .../fake_sigreturn_bad_size_for_magic0.c | 57 +++++++++++++++++++
> 2 files changed, 58 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/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore
> index 0ea6fdc3765c..cf2a73599818 100644
> --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore
> +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore
> @@ -5,3 +5,4 @@ mangle_pstate_invalid_mode_el2
> mangle_pstate_invalid_mode_el3
> mangle_pstate_ssbs_regs
> fake_sigreturn_bad_magic
> +fake_sigreturn_bad_size_for_magic0
> 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..2f53c4740c85
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
> @@ -0,0 +1,57 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright (C) 2019 ARM Limited */
> +
#include <signal.h> ?
> +#include <stdio.h>
> +#include <ucontext.h>
> +
> +#include "test_signals_utils.h"
> +#include "testcases.h"
> +
> +struct fake_sigframe sf;
> +
> +#define MIN_SZ_ALIGN 16
> +
> +static int fake_sigreturn_bad_size_for_magic0_run(struct tdescr *td,
> + siginfo_t *si, ucontext_t *uc)
> +{
> + size_t resv_sz, offset;
> + 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);
> + /*
> + * find the terminator, preserving existing headers
> + * and verify amount of spare room in __reserved area.
> + */
> + head = get_terminator(shead, resv_sz, &offset);
> + /*
> + * try stripping extra_context header when low on space:
> + * we need at least HDR_SZ + 16 space for the bad sized terminator.
> + */
> + if (head && resv_sz - offset < HDR_SZ + MIN_SZ_ALIGN) {
> + fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n",
> + resv_sz - offset);
> + head = get_header(shead, EXTRA_MAGIC, resv_sz, &offset);
> + }
> + /* just give up and timeout if still not enough space */
> + if (head && resv_sz - offset >= HDR_SZ + MIN_SZ_ALIGN) {
> + head->magic = 0;
> + head->size = MIN_SZ_ALIGN;
This is different from the amount of space we tested for
(HDR_SZ + MIN_SZ_ALIGN) earlier.
I'm not sure it matters which we use, but we should be consistent.
I suggest sticking with HDR_SZ, unless there's something I've missed.
[...]
Cheers
---Dave
