main.c File Reference

#include <zephyr/kernel.h>
#include <zephyr/ztest.h>

Macros
#define	STACKSIZE   (2048 + CONFIG_TEST_EXTRA_STACK_SIZE)

Functions
void	k_sys_fatal_error_handler (unsigned int reason, const struct arch_esf *esf)
	Fatal error policy handler.
void	check_input (const char *name, const char *input)
	check_input
void	print_loop (const char *name)
	print_loop
void	alternate_thread (void *p1, void *p2, void *p3)
	This thread passes a long string to check_input function.
	K_THREAD_STACK_DEFINE (alt_thread_stack_area,(2048+CONFIG_TEST_EXTRA_STACK_SIZE))
	ZTEST_USER (stackprot, test_stackprot)
	test Stack Protector feature using canary
	ZTEST (stackprot, test_create_alt_thread)
	Test optional mechanism to detect stack overflow.
void	alternate_thread_canary (void *arg1, void *arg2, void *arg3)
	This thread checks its canary value against its parent canary.
	ZTEST (stackprot, test_canary_value)
	Test stack canaries behavior.
	ZTEST_SUITE (stackprot, NULL, NULL, NULL, NULL, NULL)

Variables
static ZTEST_BMEM int	count
static ZTEST_BMEM int	ret = TC_PASS
static struct k_thread	alt_thread_data

Macro Definition Documentation

STACKSIZE

#define STACKSIZE   (2048 + CONFIG_TEST_EXTRA_STACK_SIZE)

Function Documentation

alternate_thread()

void alternate_thread	(	void *	p1,
		void *	p2,
		void *	p3
	)

This thread passes a long string to check_input function.

It terminates due to stack overflow and reports "Stack Check Fail" when stack protection feature is enabled. Hence it will not execute the print_loop function and will not set ret to TC_FAIL.

alternate_thread_canary()

void alternate_thread_canary	(	void *	arg1,
		void *	arg2,
		void *	arg3
	)

This thread checks its canary value against its parent canary.

If CONFIG_STACK_CANARIES_TLS is enabled, it is expected that the canaries have different values, otherwise there is only one global canary and the value should be the same.

check_input()

void check_input	(	const char *	name,
		const char *	input
	)

check_input

This function copies the input string to a buffer of 16 characters and prints the name and buffer as a string. If the input string is longer than the buffer, an error condition is detected.

When stack protection feature is enabled (see prj.conf file), the system error handler is invoked and reports a "Stack Check Fail" error. When stack protection feature is not enabled, the system crashes with error like: Trying to execute code outside RAM or ROM.

K_THREAD_STACK_DEFINE()

K_THREAD_STACK_DEFINE	(	alt_thread_stack_area	,
		(2048+CONFIG_TEST_EXTRA_STACK_SIZE)
	)

print_loop()

void print_loop

(

const char *

name

)

print_loop

This function calls check_input 6 times with the input name and a short string, which is printed properly by check_input.

Parameters

name	caller identification string

ZTEST() [1/2]

ZTEST	(	stackprot	,
		test_canary_value
	)

Test stack canaries behavior.

Test that canaries value are different between threads when CONFIG_STACK_CANARIES_TLS is enabled.

ZTEST() [2/2]

ZTEST	(	stackprot	,
		test_create_alt_thread
	)

Test optional mechanism to detect stack overflow.

Test that the system provides an optional mechanism to detect when supervisor threads overflow stack memory buffer.

ZTEST_SUITE()

ZTEST_SUITE	(	stackprot	,
		NULL	,
		NULL	,
		NULL	,
		NULL	,
		NULL
	)

ZTEST_USER()

ZTEST_USER	(	stackprot	,
		test_stackprot
	)

test Stack Protector feature using canary

This is the test program to test stack protection using canary. The main thread starts a second thread, which generates a stack check failure. By design, the second thread will not complete its execution and will not set ret to TC_FAIL. This is the entry point to the test stack protection feature. It starts the thread that tests stack protection, then prints out a few messages before terminating.

Variable Documentation

alt_thread_data

struct k_thread alt_thread_data

static

count

ZTEST_BMEM int count

static

ret

ZTEST_BMEM int ret = TC_PASS

static