:orphan:

.. title:: STACK_SENTINEL

.. option:: CONFIG_STACK_SENTINEL

*Enable stack sentinel*

Type: ``bool``

Help
====

Store a magic value at the lowest addresses of a thread's stack.
Periodically check that this value is still present and kill the
thread gracefully if it isn't. This is currently checked in four
places:

1) Upon any context switch for the outgoing thread
2) Any hardware interrupt that doesn't context switch, the check is
   performed for the interrupted thread
3) When a thread returns from its entry point
4) When a thread calls k_yield() but doesn't context switch

This feature doesn't prevent corruption and the system may be
in an unusable state. However, given the bizarre behavior associated
with stack overflows, knowledge that this is happening is very
useful.

This feature is intended for those systems which lack hardware support
for stack overflow protection, or have insufficient system resources
to use that hardware support.

Direct dependencies
===================

!\ :option:`USERSPACE <CONFIG_USERSPACE>`

*(Includes any dependencies from ifs and menus.)*

Defaults
========

No defaults. Implicitly defaults to ``n``.

Symbols selected by this symbol
===============================

- \ :option:`THREAD_STACK_INFO <CONFIG_THREAD_STACK_INFO>`

Kconfig definition
==================

.. highlight:: kconfig

At ``subsys/debug/Kconfig:145``

Included via ``Kconfig:8`` → ``Kconfig.zephyr:34`` → ``subsys/Kconfig:17``

Menu path: (Top) → Sub Systems and OS Services → Debugging Options

.. parsed-literal::

    config STACK_SENTINEL
    	bool "Enable stack sentinel"
    	select \ :option:`THREAD_STACK_INFO <CONFIG_THREAD_STACK_INFO>`
    	depends on !\ :option:`USERSPACE <CONFIG_USERSPACE>`
    	help
    	  Store a magic value at the lowest addresses of a thread's stack.
    	  Periodically check that this value is still present and kill the
    	  thread gracefully if it isn't. This is currently checked in four
    	  places:
	  
    	  1) Upon any context switch for the outgoing thread
    	  2) Any hardware interrupt that doesn't context switch, the check is
    	     performed for the interrupted thread
    	  3) When a thread returns from its entry point
    	  4) When a thread calls k_yield() but doesn't context switch
	  
    	  This feature doesn't prevent corruption and the system may be
    	  in an unusable state. However, given the bizarre behavior associated
    	  with stack overflows, knowledge that this is happening is very
    	  useful.
	  
    	  This feature is intended for those systems which lack hardware support
    	  for stack overflow protection, or have insufficient system resources
    	  to use that hardware support.

*(The 'depends on' condition includes propagated dependencies from ifs and menus.)*