/* * 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 */ /*---------------------------------------------------------------------------*/ /** @} */