On 04/09/2019 12:49, Dave Martin wrote:
> 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).
>
Ok
> For now, let's get this series settled as-is -- so, after responding to
> nits:
>
> Reviewed-by: Dave Martin <Dave.Martin@xxxxxxx>
>
Thanks
Cristian
