hardfault with sprintf/snprintf/vsprintf/vsnprintf, newlib, newlibnano, tinyprintf

Posted by luk1990 on October 5, 2017
Hello Im having quite trouble finding the reason for my current hardfault. Im using freertos with static memory allocation (no malloc ever used) i use new with pre allocated buffers (new (&buffer). i have made sure that all threads are are aligned(4). whenever i use a form of printf, my application jumps to the hardfault from the freertos call “start first task”. i write “embedded C++” code, what is basically C89 with namespaces and classes, so nothing other than is included from c++. each include from c files (.h) are wrapped with extern “C” so there is never ever a linkage issue. i have tested with newlib, newlib nano and the tinyprintf from spare time libs. no difference. also, i have never an assert failure on the malloc calls, so i am “quite” sure no newlib function accesses malloc (am i right here?) the internet suggests its either a dynamic memory allocation issue or a stack issue. how can i prove what is causing the hardfault? i believe the hint my stack gets corrupted because of my printf calls isnt that wrong. how can i prove this? (i have never debugged stacks and would need some help debugging the stack pointer). any other ideas? thank you very much example: ~~~ (void) vsnprintf( logbuffer, CLOGBUFFERSIZE, format, args ); // hardfault (void) sprintf( _logbuffer, “huhu” ); // no hardfault ~~~ dynamic allocation overwrites: ~~~ __ATLLINKEXTERNC void *malloc( sizet size ) { (void) size; atl::os::assert::failed((char*)FILE,LINE); return NULL; } __ATLLINKEXTERNC void * calloc(sizet size1, size_t size2) { (void) size1; (void) size2; atl::os::assert::failed((char*)FILE,LINE); return NULL; } __ATLLINKEXTERNC void *realloc(void * ptr, sizet size) { (void) ptr; (void) size; atl::os::assert::failed((char*)FILE,LINE); return NULL; } __ATLLINKEXTERN_C void free( void * ptr ) { (void) ptr; atl::os::assert::failed((char*)FILE,LINE); } ~~~ freertos config: ~~~ /* FreeRTOS V9.0.0 – Copyright (C) 2016 Real Time Engineers Ltd. All rights reserved 
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

This file is part of the FreeRTOS distribution.

FreeRTOS is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License (version 2) as published by the
Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.

***************************************************************************
>>!   NOTE: The modification to the GPL is included to allow you to     !<<
>>!   distribute a combined work that includes FreeRTOS without being   !<<
>>!   obliged to provide the source code for proprietary components     !<<
>>!   outside of the FreeRTOS kernel.                                   !<<
***************************************************************************

FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  Full license text is available on the following
link: http://www.freertos.org/a00114.html

***************************************************************************
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defined configASSERT()?

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1 tab == 4 spaces!
*/

ifndef FREERTOSCONFIGH

define FREERTOSCONFIGH

/———————————————————– * Application specific definitions. * * These definitions should be adjusted for your particular hardware and * application requirements. * * THESE PARAMETERS ARE DESCRIBED WITHIN THE ‘CONFIGURATION’ SECTION OF THE * FreeRTOS API DOCUMENTATION AVAILABLE ON THE FreeRTOS.org WEB SITE. * * See http://www.freertos.org/a00110.html. *———————————————————-/ /* USER CODE BEGIN Includes /
/ Section where include file can be added / / USER CODE END Includes */ /* Ensure stdint is only used by the compiler, and not the assembler. */

if defined(ICCARM) || defined(CC_ARM) || defined(GNUC__)

#include <stdint.h>
extern uint32_t SystemCoreClock;
/* USER CODE BEGIN 0 /
extern void configureTimerForRunTimeStats(void); extern unsigned long getRunTimeCounterValue(void);
/ USER CODE END 0 */

endif

define configUSE_PREEMPTION 1

define configSUPPORTSTATICALLOCATION 1

define configSUPPORTDYNAMICALLOCATION 0

define configUSEIDLEHOOK 1

define configUSETICKHOOK 1

define configCPUCLOCKHZ ( SystemCoreClock )

define configTICKRATEHZ ((TickType_t)1000)

define configMAX_PRIORITIES ( 7 )

define configMINIMALSTACKSIZE ((uint16_t)32) // MOD was 128

define configMAXTASKNAME_LEN ( 32 ) // mod was 16

define configGENERATERUNTIME_STATS 1

define configUSETRACEFACILITY 1

define configUSESTATSFORMATTING_FUNCTIONS 1

define configUSE16BIT_TICKS 0

define configUSE_MUTEXES 1

define configQUEUEREGISTRYSIZE 8

define configCHECKFORSTACK_OVERFLOW 1

define configUSEMALLOCFAILED_HOOK 1

define configUSEDAEMONTASKSTARTUPHOOK 1

define configUSEPORTOPTIMISEDTASKSELECTION 1

/* Co-routine definitions. */

define configUSECOROUTINES 0

define configMAXCOROUTINE_PRIORITIES ( 2 )

/* Software timer definitions. */

define configUSE_TIMERS 1

define configTIMERTASKPRIORITY ( 2 )

define configTIMERQUEUELENGTH 10

define configTIMERTASKSTACK_DEPTH 256

/* Set the following definitions to 1 to include the API function, or zero to exclude the API function. */

define INCLUDE_vTaskPrioritySet 1

define INCLUDE_uxTaskPriorityGet 1

define INCLUDE_vTaskDelete 1

define INCLUDE_vTaskCleanUpResources 1

define INCLUDE_vTaskSuspend 1

define INCLUDE_vTaskDelayUntil 1

define INCLUDE_vTaskDelay 1

define INCLUDE_xTaskGetSchedulerState 1

define INCLUDE_xTimerPendFunctionCall 1

define INCLUDE_xQueueGetMutexHolder 1

define INCLUDE_xSemaphoreGetMutexHolder 1

define INCLUDE_pcTaskGetTaskName 1

define INCLUDE_uxTaskGetStackHighWaterMark 1

define INCLUDE_xTaskGetCurrentTaskHandle 1

define INCLUDE_eTaskGetState 1

define INCLUDE_xTaskAbortDelay 1

define INCLUDE_xTaskGetHandle 1

/* Cortex-M specific definitions. */

ifdef __NVICPRIOBITS

/* __BVICPRIOBITS will be specified when CMSIS is being used. */ #define configPRIO_BITS __NVIC_PRIO_BITS

else

#define configPRIO_BITS 4

endif

/* The lowest interrupt priority that can be used in a call to a “set priority” function. */

define configLIBRARYLOWESTINTERRUPT_PRIORITY 15

/* The highest interrupt priority that can be used by any interrupt service routine that makes calls to interrupt safe FreeRTOS API functions. DO NOT CALL INTERRUPT SAFE FREERTOS API FUNCTIONS FROM ANY INTERRUPT THAT HAS A HIGHER PRIORITY THAN THIS! (higher priorities are lower numeric values. */

define configLIBRARYMAXSYSCALLINTERRUPTPRIORITY 5

/* Interrupt priorities used by the kernel port layer itself. These are generic to all Cortex-M ports, and do not rely on any particular library functions. */

define configKERNELINTERRUPTPRIORITY ( configLIBRARYLOWESTINTERRUPTPRIORITY << (8 – configPRIOBITS) )

/* !!!! configMAXSYSCALLINTERRUPT_PRIORITY must not be set to zero !!!! See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html. */

define configMAXSYSCALLINTERRUPTPRIORITY ( configLIBRARYMAXSYSCALLINTERRUPTPRIORITY << (8 – configPRIOBITS) )

/* Normal assert() semantics without relying on the provision of an assert.h header file. / / USER CODE BEGIN 1 */

define configASSERT( x ) if ((x) == 0) {taskDISABLE_INTERRUPTS(); for( ;; );}

/* USER CODE END 1 */ /* Definitions that map the FreeRTOS port interrupt handlers to their CMSIS standard names. */

define vPortSVCHandler SVC_Handler

define xPortPendSVHandler PendSV_Handler

/* IMPORTANT: This define MUST be commented when used with STM32Cube firmware, to prevent overwriting SysTickHandler defined within STM32Cube HAL */ /* #define xPortSysTickHandler SysTickHandler */ /* USER CODE BEGIN 2 /
/ Definitions needed when configGENERATERUNTIME_STATS is on */

define portCONFIGURETIMERFORRUNTIME_STATS configureTimerForRunTimeStats

define portGETRUNTIMECOUNTERVALUE getRunTimeCounterValue

/* USER CODE END 2 */ /* USER CODE BEGIN Defines /
/ Section where parameter definitions can be added (for instance, to override default ones in FreeRTOS.h) / / USER CODE END Defines */

endif /* FREERTOSCONFIGH */

~~~

hardfault with sprintf/snprintf/vsprintf/vsnprintf, newlib, newlibnano, tinyprintf

Posted by rtel on October 7, 2017
Sorry for the late reply, but your post went into moderation, which its not supposed to do. I would recommend setting configCHECKFORSTACK_OVERFLOW to 2 rather than 1, but other than that, you have the ‘normal’ suggestions covered already (like having configASSERT() defined). I can’t comment on the C++ stuff though as we only test in C projects – although there are lots of people using FreeRTOS with C++. Stack overflow is the most common issue with the printf() family of functions. Have you tried debugging the hard fault? http://www.freertos.org/Debugging-Hard-Faults-On-Cortex-M-Microcontrollers.html

hardfault with sprintf/snprintf/vsprintf/vsnprintf, newlib, newlibnano, tinyprintf

Posted by gourmetsel on October 9, 2017
The link provided above helped us some months ago to find the cause of a hard fault. We ported software from one processor to another from the same family. The problem in our case was the maximum clock frequency being exceeded. This did not lead to an immediate hard fault. Are you sure the calls to printf are actually the problem? Is your code running flawlessly without these calls? Regarding your question on stack overflow, this page is also a good read: http://www.freertos.org/Stacks-and-stack-overflow-checking.html If you have ways to examine your memory when single-stepping through your code, you could also check your task stack at task creation and after you ran into the hard fault. This should give you a first indication whether you run into an overflow.

hardfault with sprintf/snprintf/vsprintf/vsnprintf, newlib, newlibnano, tinyprintf

Posted by heinbali01 on October 10, 2017
Hi, if you think that the problem is in vsnprintf(), you may want to try this version of printf-stdarg.c which is part of the of the FreeRTOS+TCP library. Just link it into your project and provide the 2 functions described in my post. Some questions to you:
  • does that function alway crash?
  • can you show us some code that calls vsnprintf()?
  • how did you implement C++ new method?
  • do you use printf() function from within an ISR?