Thread (37 messages) 37 messages, 2 authors, 2019-07-03

Re: [PATCH 06/13] kselftest: arm64: mangle_pstate_invalid_state_toggle

From: Dave Martin <Dave.Martin@arm.com>
Date: 2019-06-21 10:39:40
Also in: linux-kselftest

On Thu, Jun 13, 2019 at 12:13:28PM +0100, Cristian Marussi wrote:
Added a simple mangle testcase which messes with the ucontext_t
from within the sig_handler, trying to toggle PSTATE state bits
to switch the system between 32bit/64bit execution state.
Expects SIGSEGV on test PASS.
Maybe say "compat_toggle" instead of "state_toggle" in the test name.
"state" is a bit of a generic term.

Once upon a time, the kernel didn't prohibit this toggle, which was a
"cool feature" before compat existed for real.  I think this probably
got sorted before the initial arm64 port was upstreamed.
quoted hunk ↗ jump to hunk
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 .../arm64/signal/testcases/.gitignore         |  1 +
 .../mangle_pstate_invalid_state_toggle.c      | 25 +++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_state_toggle.c
diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore
index a609a08b744f..91f7aee4b666 100644
--- a/tools/testing/selftests/arm64/signal/testcases/.gitignore
+++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore
@@ -1,3 +1,4 @@
 mangle_sp_misaligned
 mangle_pc_invalid
 mangle_pstate_invalid_daif_bits
+mangle_pstate_invalid_state_toggle
diff --git a/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_state_toggle.c b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_state_toggle.c
new file mode 100644
index 000000000000..971193e7501b
--- /dev/null
+++ b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_state_toggle.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_MODE32_BIT;
As for other tests, is there a way to sanity-check that the SIGSEGV was
generated by sigreturn itself?

[...]

Cheers
---Dave

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