On Thu, Jun 13, 2019 at 12:13:27PM +0100, Cristian Marussi wrote:
Added a simple mangle testcase which messes with the ucontext_t from within the sig_handler, trying to set PSTATE DAIF bits to an invalid value (masking everything). Expects SIGSEGV on test PASS.
Signed-off-by: Cristian Marussi cristian.marussi@arm.com
.../arm64/signal/testcases/.gitignore | 1 + .../mangle_pstate_invalid_daif_bits.c | 25 +++++++++++++++++++ 2 files changed, 26 insertions(+) create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c
diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore index a87fb0f0d2cf..a609a08b744f 100644 --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore @@ -1,2 +1,3 @@ mangle_sp_misaligned mangle_pc_invalid +mangle_pstate_invalid_daif_bits diff --git a/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c new file mode 100644 index 000000000000..710681cba59c --- /dev/null +++ b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_daif_bits.c @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2019 ARM Limited */
+#include "test_signals_utils.h" +#include "testcases.h"
+static int mangle_invalid_pstate_run(struct tdescr *td, siginfo_t *si,
ucontext_t *uc)+{
- ASSERT_GOOD_CONTEXT(uc);
- /* This config should trigger a SIGSEGV by Kernel */
- uc->uc_mcontext.pstate |= PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT;
It may be worth commenting to mention what we're testing in the kernel here: in this case, we're checking that valid_native_regs() is called to police the new pstate value, and to check that it does the right thing.
Is there a way to check that the SIGSEGV comes from the sigreturn and not from something else?
It looks like the SIGSEGV should have si_code == SEGV_ACCERR and si_addr == <sigframe base address> in this case. uc_mcontext.pc will also point into sigtramp in the vdso, which we may be able to check somehow.
We don't have to have a bulletproof check here, but it would be nice to have some kind of sanity-check at least.
[...]
Cheers ---Dave