tests/arch/arm/arm_user_stack_test/arch.arm.user.stack failure on mps2_an385

[carlescufi]

Describe the bug

Test tests/arch/arm/arm_user_stack_test/arch.arm.user.stack fails on mps2_an385 on CI

Regression

• This is a regression.

Steps to reproduce

Locally:
SHA: 0589958
west twister -p mps2/an385 -s arch.arm.user.stack

❯ qemu-system-arm --version
QEMU emulator version 10.1.2
Copyright (c) 2003-2025 Fabrice Bellard and the QEMU Project developers

Relevant log output

INFO    - 945/945 mps2/an385                arch.arm.user.stack                                FAILED Testsuite failed (qemu 1.826s <zephyr>)
INFO    - /__w/zephyr/zephyr/twister-out/mps2_an385/zephyr/tests/arch/arm/arm_user_stack_test/arch.arm.user.stack/handler.log
ERROR   - *** Booting Zephyr OS build v4.3.0-rc1-108-gd5b297cae4c8 ***
Running TESTSUITE arm_user_stack_test
===================================================================
START - test_arm_user_stack_corruption
Call low_fn from user
Call hi_fn from user
Call attack_entry from kernel
Changed the kernel_secret so marking test as failed
 FAIL - test_arm_user_stack_corruption in 0.061 seconds
===================================================================
TESTSUITE arm_user_stack_test failed.

------ TESTSUITE SUMMARY START ------

SUITE FAIL -   0.00% [arm_user_stack_test]: pass = 0, fail = 1, skip = 0, total = 1 duration = 0.061 seconds
 - FAIL - [arm_user_stack_test.test_arm_user_stack_corruption] duration = 0.061 seconds

------ TESTSUITE SUMMARY END ------

===================================================================
RunID: 00846c07b9b03f4db0ecc54da853c8f1
PROJECT EXECUTION FAILED
hi_thread_runs: 5998
 ERROR: cannot pass in test phase 'teardown()', bailing

INFO    - /__w/zephyr/zephyr/twister-out/mps2_an385/zephyr/tests/arch/arm/arm_user_stack_test/arch.arm.user.stack/handler.log
INFO    - 4 Iteration:
INFO    - Adding tasks to the queue...
INFO    - Added initial list of jobs to queue

INFO    - 945/945 mps2/an385                arch.arm.user.stack                                FAILED Testsuite failed (qemu 1.780s <zephyr>)
INFO    - /__w/zephyr/zephyr/twister-out/mps2_an385/zephyr/tests/arch/arm/arm_user_stack_test/arch.arm.user.stack/handler.log
ERROR   - *** Booting Zephyr OS build v4.3.0-rc1-108-gd5b297cae4c8 ***
Running TESTSUITE arm_user_stack_test
===================================================================
START - test_arm_user_stack_corruption
Call low_fn from user
Call hi_fn from user
Call attack_entry from kernel
Changed the kernel_secret so marking test as failed
 FAIL - test_arm_user_stack_corruption in 0.061 seconds
===================================================================
TESTSUITE arm_user_stack_test failed.

------ TESTSUITE SUMMARY START ------

SUITE FAIL -   0.00% [arm_user_stack_test]: pass = 0, fail = 1, skip = 0, total = 1 duration = 0.061 seconds
 - FAIL - [arm_user_stack_test.test_arm_user_stack_corruption] duration = 0.061 seconds

------ TESTSUITE SUMMARY END ------

===================================================================
RunID: 00846c07b9b03f4db0ecc54da853c8f1
PROJECT EXECUTION FAILED
hi_thread_runs: 5998
 ERROR: cannot pass in test phase 'teardown()', bailing

Impact

Showstopper – Prevents release or major functionality; system unusable.

Environment

Zephyr GitHub CI

Additional Context

No response

[wearyzen]

Below are results with debugging with gdb:
On shell 1:

qemu-system-arm -cpu cortex-m3 -machine mps2-an385 -nographic -vga none -net none -pidfile qemu.pid -chardev stdio,id=con,mux=on -serial ch
ardev:con -mon chardev=con,mode=readline -icount shift=7,align=off,sleep=off -rtc clock=vm -kernel twister-out/mps2_an385/zephyr/tests/arch/arm/arm_user_stack_test/arch.arm.user.stack/zephyr/zephyr.elf
qemu-system-arm: warning: nic lan9118.0 has no peer
*** Booting Zephyr OS build v4.2.0-6962-g1dc7eb995d1d ***
Running TESTSUITE arm_user_stack_test
===================================================================
START - test_arm_user_stack_corruption
Call low_fn from user
Call hi_fn from user
Call attack_entry from kernel
Changed the kernel_secret so marking test as failed
 FAIL - test_arm_user_stack_corruption in 1.341 seconds
===================================================================
TESTSUITE arm_user_stack_test failed.

------ TESTSUITE SUMMARY START ------

SUITE FAIL -   0.00% [arm_user_stack_test]: pass = 0, fail = 1, skip = 0, total = 1 duration = 1.341 seconds
 - FAIL - [arm_user_stack_test.test_arm_user_stack_corruption] duration = 1.341 seconds

------ TESTSUITE SUMMARY END ------

===================================================================
RunID: 969f06878eacf231ac4971e3f1f35bf7
PROJECT EXECUTION FAILED
qemu-system-arm: terminating on signal 2

on Shell 2:

zephyr-sdk-0.17.4/arm-zephyr-eabi/bin/arm-zephyr-eabi-gdb-py zephyrproject/zephyr/twister-out/mps2_an385/zephyr/tests/arch/arm/arm_user_stack_test/arch.arm.user.stack/zephyr/zephyr.elf
>>> target remote localhost:1234
>>> c

If we let it continue, the test fails.

but if on Shell 2 with gdb if we try below instead:

zephyr-sdk-0.17.4/arm-zephyr-eabi/bin/arm-zephyr-eabi-gdb-py zephyrproject/zephyr/twister-out/mps2_an385/zephyr/tests/arch/arm/arm_user_stack_test/arch.arm.user.stack/zephyr/zephyr.elf
>>> target remote localhost:1234
>>> b low_fn
>>> c
>>> b attack_entry
>>> c
>>> c

the test passes with qemu as well:

qemu-system-arm -cpu cortex-m3 -machine mps2-an385 -nographic -vga none -net none -pidfile qemu.pid -chardev stdio,id=con,mux=on -serial ch
ardev:con -mon chardev=con,mode=readline -icount shift=7,align=off,sleep=off -rtc clock=vm -kernel twister-out/mps2_an385/zephyr/tests/arch/arm/arm_user_stack_test/arch.arm.user.stack/zephyr/zephyr.elf -s -S
qemu-system-arm: warning: nic lan9118.0 has no peer
*** Booting Zephyr OS build v4.2.0-6962-g1dc7eb995d1d ***
Running TESTSUITE arm_user_stack_test
===================================================================
START - test_arm_user_stack_corruption
qemu-system-arm: warning: icount sleep disabled and no active timers
Call hi_fn from user
Call low_fn from user
Call attack_entry from user
E: ***** MPU FAULT *****
E:   Data Access Violation
E:   MMFAR Address: 0x200014a0
E: r0/a1:  0x0000b613  r1/a2:  0x0000b5fc  r2/a3:  0x00000001
E: r3/a4:  0x200014a0 r12/ip:  0x0000a097 r14/lr:  0x00000bd5
E:  xpsr:  0x21000000
E: Faulting instruction address (r15/pc): 0x00000bda
E: >>> ZEPHYR FATAL ERROR 2: Stack overflow on CPU 0
E: Current thread: 0x200010b0 (unknown)
 PASS - test_arm_user_stack_corruption in 1.503 seconds
===================================================================
TESTSUITE arm_user_stack_test succeeded

------ TESTSUITE SUMMARY START ------

SUITE PASS - 100.00% [arm_user_stack_test]: pass = 1, fail = 0, skip = 0, total = 1 duration = 1.503 seconds
 - PASS - [arm_user_stack_test.test_arm_user_stack_corruption] duration = 1.503 seconds

------ TESTSUITE SUMMARY END ------

===================================================================
RunID: 969f06878eacf231ac4971e3f1f35bf7
PROJECT EXECUTION SUCCESSFUL