arm: cortex_m: enable null-pointer exception detection in the tests

Enable the null-pointer dereferencing detection by default throughout the test-suite. Explicitly disable this for the gen_isr_table test which needs to perform vector table reads. Disable null-pointer exception detection on qemu_cortex_m3 board, as DWT it is not emulated by QEMU on this platform. Additionally, disable null-pointer exception detection on mps2_an521 (QEMU target), as DWT is not present and the MPU based solution won't work, since the target does not have the area 0x0 - 0x400 mapped, but the QEMU still permits read access. Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
zephyrproject-rtos · Mar 3, 2021 · 1b22f6b · 1b22f6b
1 parent d86d2c6
commit 1b22f6b
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diff --git a/arch/arm/core/aarch32/cortex_m/Kconfig b/arch/arm/core/aarch32/cortex_m/Kconfig
@@ -310,6 +310,9 @@ endmenu
 
 choice CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION
 	bool "Enable and use null-pointer exception"
+	default CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION_DWT if TEST_ARM_CORTEX_M && !ARM_NONSECURE_FIRMWARE && CPU_CORTEX_M_HAS_DWT
+	default CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION_MPU if TEST_ARM_CORTEX_M && !ARM_NONSECURE_FIRMWARE && ARM_MPU && !CPU_CORTEX_M_HAS_DWT
+	default CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION_NONE
 	help
 	  There are 2 implementations available, one based
 	  on DWT and the other based on MPU. Use this choice

diff --git a/boards/arm/mps2_an521/Kconfig.defconfig b/boards/arm/mps2_an521/Kconfig.defconfig
@@ -3,6 +3,14 @@
 
 if BOARD_MPS2_AN521
 
+# MPU-based null-pointer dereferencing detection cannot
+# be applied as the (0x0 - 0x400) is unmapped but QEMU
+# will still permit bus access.
+choice CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION
+	bool
+	default CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION_NONE if QEMU_TARGET
+endchoice
+
 config BOARD
 	default "mps2_an521_nonsecure" if TRUSTED_EXECUTION_NONSECURE
 	default "mps2_an521"

diff --git a/boards/arm/qemu_cortex_m3/Kconfig.defconfig b/boards/arm/qemu_cortex_m3/Kconfig.defconfig
@@ -12,4 +12,10 @@ config GPIO_STELLARIS
 	default y
 	depends on GPIO
 
+# DWT is not properly emulated in QEMU
+choice CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION
+	bool
+	default CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION_NONE
+endchoice
+
 endif # BOARD_QEMU_CORTEX_M3
diff --git a/tests/kernel/gen_isr_table/testcase.yaml b/tests/kernel/gen_isr_table/testcase.yaml
@@ -1,18 +1,25 @@
 tests:
   arch.interrupt.gen_isr_table.arm_baseline:
+    arch_allow: arm
     platform_allow: bbc_microbit atsamr21_xpro nrf51dk_nrf51422 nucleo_g071rb qemu_cortex_m0
     filter: CONFIG_GEN_ISR_TABLES and CONFIG_ARMV6_M_ARMV8_M_BASELINE
     tags: interrupt isr_table
+    extra_configs:
+      - CONFIG_CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION_NONE=y
   arch.interrupt.gen_isr_table.arm_mainline:
+    arch_allow: arm
     platform_exclude: stmf103_mini nucleo_f103rb olimexino_stm32 stm32_min_dev_black
         stm32_min_dev_blue usb_kw24d512 v2m_beetle cc1352r1_launchxl
         cc26x2r1_launchxl olimex_stm32_h103 cc1352r_sensortag
     filter: CONFIG_GEN_ISR_TABLES and CONFIG_ARMV7_M_ARMV8_M_MAINLINE
     tags: interrupt isr_table
+    extra_configs:
+      - CONFIG_CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION_NONE=y
   arch.interrupt.gen_isr_table.disabled:
     arch_allow: arm
     extra_configs:
       - CONFIG_GEN_ISR_TABLES=n
+      - CONFIG_CORTEX_M_DEBUG_NULL_POINTER_EXCEPTION_DETECTION_NONE=y
     tags: interrupt isr_table
     build_only: true
   arch.interrupt.gen_isr_table.arc: