Finding a call stack programmatically (unwind?).

[wdtj]

I am attempting to write a routine that monitors the heap in order to track down a memory leak.  I've seen similar tools on other platforms and found them quite helpful.  To make this even more effective, I want to record the caller to malloc() that made the request. To do this, the routine would need to read the call stack (sometimes called unwind).  I've been googling and found clues for the GNU compiler, and other platforms but nothing that seems pertinent to my platform: nRF52840/ARM/IAR/FreeRTOS.

I realize this is extremely unportable, but this is only needed for debugging on occasion.

Anyone have any suggestions?  I've seen references to unwind.h, but they appear to only be for GNU.

[Håkon Alseth]

Hi,

 

malloc is a part of the compiler suite libc.

These issues are usually tracked with entering debug mode and having a plugin to make your IDE rtos-aware. I am not sure what IAR offers, but it seems that they have something for freertos:

https://www.iar.com/products/integrations/

 

Kind regards,

Håkon

[wdtj]

Thanks, but that's not what I asked.  I am aware that IAR (and other IDEs) have the ability to generate a call stack after stopping the processor.  What I was after is getting the program itself to tell me who called this function/method.  This allows me to log these callers and identify them long after the event has happened.  In this case, when the malloc is called, I would log the event along with the caller's location.  After detecting that this buffer was not returned, I can then look up what the buffer was requested for, and thus determine why it was not returned to the heap.  Other environments, like Linux, Unix, and Windows have this capability. 

[Håkon Alseth]

Hi,

 

*alloc() functions is provded by the libc, which is provided by IAR in your case.

I would recommend that you ask IAR if they have a heap allocation/profiling functionality available.

 

Kind regards,

Håkon

[wdtj]

To reiterate: I am not interested in the malloc itself, I am just referencing that for context.  What I am interested in is how to access the caller stack.  This involves getting access to the sp and/or lr registers and walking through the stack.  Is the stack defined by IAR or ARM or Nordic.  Call stack unwinding is a critical piece of debugging, either live through a IDE or in postmortem as in this case.

I am in touch with IAR, and their as confused by this as you folks.

Thanks.

[hmolesworth]

Most useful if you can get it working; last time I looked I saw this with a couple of git links at the end: unwinding-stack-on-cortex-m-with-freertos also CmBacktrace which has an IAR example