configLIST_VOLATILE required - Missing configASSERT in listREMOVE_ITEM

Kernel
#1

Using the provided sample code for the PIC32 platform and FreeRTOS v202112.00. I ran into an issue in tasks.c when enabling the compiler optimizations (XC32 v4.00 compiler, -O2 optimization).

The exception happens in xTaskResumeAll() when the listREMOVE_ITEM macro tries to remove an item with a null pointer as the container. The macro creates a pointer pxList and de-references it without checking if it is NULL, causing an exception.

In my case, it seemed to be caused by an aggressive compiler and the fix was to add #define configLIST_VOLATILE volatile in FreeRTOSConfig.h

I think nevertheless the pointer should be checked for non-null in the macro to gracefully handle exceptions.

#2

Hi,
Thanks for posting the query.
There are some similar posts in the following threads:

  1. Stuck in xTaskResumeAll() - Interrupt Priorities? Stack?
  2. Endless loop in 10.4.6 with -Os flag
    Please check if any of the suggested options help in your scenario.
#3

As described in this comment block, the solution you mentioned is right. Thank you for reporting it.

This list is not a general purpose list and meant for internal use only. Wherever we call remove item, it is ensured that the list is not empty. So I am sure that we need to add an extra NULL check here.