tests: arm: new test for PACBTI

Add a simple test to test branch target identification (BTI).

Signed-off-by: Sudan Landge <[email protected]>

Author: wearyzen

tests/arch/arm/arm_pacbti/CMakeLists.txt

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(arm_pacbti)
+
+target_sources(app PRIVATE src/main.c)

tests/arch/arm/arm_pacbti/prj.conf

@@ -0,0 +1,2 @@
+CONFIG_ZTEST=y
+CONFIG_ZTEST_FATAL_HOOK=y

tests/arch/arm/arm_pacbti/src/main.c

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2025 Arm Limited and/or its affiliates <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/ztest.h>
+#include <zephyr/ztest_error_hook.h>
+#include <cmsis_core.h>
+
+void test_arm_pacbti(void)
+{
+	printf("%s This should never have been called if BTI was enforced\n", __func__);
+
+	/* If func call was successful then BTI didn't work as expected */
+	ztest_test_fail();
+}
+
+ZTEST(arm_pacbti, test_arm_bti)
+{
+	/* Try jumping to middle of a random function and mark that fault as expected because if
+	 * BTI is enforced and an indirect jump is made on a non-BTI instruction then a usage fault
+	 * is generated.
+	 */
+	ztest_set_fault_valid(true);
+
+	__asm__ volatile(" ldr r1, =test_arm_pacbti\n"
+			 " add r1, #4\n"
+			 " bx r1\n");
+}
+
+ZTEST_SUITE(arm_pacbti, NULL, NULL, NULL, NULL, NULL);

tests/arch/arm/arm_pacbti/testcase.yaml

@@ -0,0 +1,14 @@
+common:
+  tags:
+    - arm
+  platform_allow:
+    - mps3/corstone310/fvp
+    - mps3/corstone310/fvp/ns
+    - mps4/corstone315/fvp
+    - mps4/corstone320/fvp
+tests:
+  arch.arm.pacbti.standard:
+    # TODO: remove skip after Zephyr sdk makes GCC 14.3 as default
+    skip: true
+    extra_configs:
+      - CONFIG_ARM_PACBTI_STANDARD=y