diff mbox series

[05/13] kselftest: arm64: mangle_pstate_invalid_daif_bits

Message ID 20190613111335.7645-6-cristian.marussi@arm.com
State New
Headers show
Series Add arm64/signal initial kselftest support | expand

Commit Message

Cristian Marussi June 13, 2019, 11:13 a.m. UTC
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

Comments

Dave Martin June 21, 2019, 10:35 a.m. UTC | #1
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
diff mbox series

Patch

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;
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.sanity_disabled = true,
+		.name = "MANGLE_PSTATE_INVALID_DAIF_BITS",
+		.descr = "Mangling uc_mcontext with INVALID DAIF_BITS",
+		.sig_trig = SIGUSR1,
+		.sig_ok = SIGSEGV,
+		.run = mangle_invalid_pstate_run,
+};