[En-Nut-Discussion] Race condition and stack overflow in tcpsm.c

[Ole Reinhardt]

Hi Philipp, Hi Harald,

>> With these changes, I still managed to crash the system after some time,
>> but it looks like a different problem this time, as all stacks should
>> still be intact.
> 
> In the first place you need to find out, where it crashes, then why it
> does. Yeah, I know, simply said but difficult to do. With ARM7 I was
> quite successful with stack back-tracing. I do not have much experience
> with Cortex, though.

For cortex, I implemented a heuristic stack backtrace mechanism, which
analyses the code to print a backtrace.

The main problem on Cortex M3/M4 is, that no frame pointer exists, which
points to the start of the previous stack frame. A real backtrace
algorithm would need to read the debugging symbols of the elf file.

However the backtrace works in most cases, if optimisation is set to -O0
and if DEBUG_MACRO and DEBUG_BACKTRACE are selected in the configurator.

Best regards,

Ole


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