nes-proj/os/sys/stack-check.c
2017-12-01 13:35:06 +00:00

163 lines
5.0 KiB
C

/*
* Copyright (c) 2017, University of Bristol - http://www.bris.ac.uk/
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
/**
* \addtogroup stack
* @{
*/
/**
* \file
* Implementation of the stack checker library.
* \author
* Atis Elsts <atis.elsts@bristol.ac.uk>
*/
#include "contiki.h"
#include "sys/stack-check.h"
#include "dev/watchdog.h"
#include <string.h>
#include "sys/log.h"
#define LOG_MODULE "Stack"
#define LOG_LEVEL LOG_LEVEL_MAIN
/*---------------------------------------------------------------------------*/
/* linker will provide a symbol for the end of the .bss segment */
extern uint8_t _stack;
#if STACK_CHECK_PERIODIC_CHECKS
PROCESS(stack_check_process, "Stack check");
#endif
/*---------------------------------------------------------------------------*/
/* The symbol with which the stack memory is initially filled */
#define STACK_FILL 0xcd
/*---------------------------------------------------------------------------*/
#ifdef STACK_ORIGIN
/* use the #defined value */
#define GET_STACK_ORIGIN() STACK_ORIGIN
#else
/* use the value provided by the linker script */
extern int _stack_origin;
#define GET_STACK_ORIGIN() (&_stack_origin)
#endif
/*---------------------------------------------------------------------------*/
void
stack_check_init(void)
{
uint8_t *p;
/* Make this static to avoid destroying it in the while loop */
static void *stack_top;
/* Use address of this local variable as a boundary */
stack_top = &p;
/* Note: this is expected to be called before the WDT is started! */
p = &_stack;
while(p < (uint8_t *)stack_top) {
*p++ = STACK_FILL;
}
#if STACK_CHECK_PERIODIC_CHECKS
/* Start the periodic checker process */
process_start(&stack_check_process, NULL);
#endif
}
/*---------------------------------------------------------------------------*/
uint16_t
stack_check_get_usage(void)
{
uint8_t *p = &_stack;
/* Make sure WDT is not triggered */
watchdog_periodic();
/* Skip the bytes used after heap; it's 1 byte by default for _stack,
* more than that means dynamic memory allocation is used somewhere.
*/
while(*p != STACK_FILL && p < (uint8_t *)GET_STACK_ORIGIN()) {
p++;
}
/* Skip the region of the memory reserved for the stack not used yet by the program */
while(*p == STACK_FILL && p < (uint8_t *)GET_STACK_ORIGIN()) {
p++;
}
/* Make sure WDT is not triggered */
watchdog_periodic();
if(p >= (uint8_t*)GET_STACK_ORIGIN()) {
/* This means the stack is screwed. */
return 0xffff;
}
return (uint8_t *)GET_STACK_ORIGIN() - p;
}
/*---------------------------------------------------------------------------*/
uint16_t
stack_check_get_reserved_size(void)
{
return (uint8_t *)GET_STACK_ORIGIN() - &_stack;
}
/*---------------------------------------------------------------------------*/
#if STACK_CHECK_PERIODIC_CHECKS
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(stack_check_process, ev, data)
{
static struct etimer et;
PROCESS_BEGIN();
etimer_set(&et, STACK_CHECK_PERIOD);
while(1) {
uint16_t actual, allowed;
PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));
actual = stack_check_get_usage();
allowed = stack_check_get_reserved_size();
if(actual > allowed) {
LOG_ERR("Check failed: %u vs. %u\n", actual, allowed);
} else {
LOG_DBG("Check ok: %u vs. %u\n", actual, allowed);
}
etimer_reset(&et);
}
PROCESS_END();
}
/*---------------------------------------------------------------------------*/
#endif /* STACK_CHECK_PERIODIC_CHECKS */
/*---------------------------------------------------------------------------*/
/** @} */