Differentiate .bss from heap accesses

Hi, As I understand, the [heap] virtual memory area (VMA) in the process address space in Linux, contains both the .bss data and the heap data (Link).

I want to capture heap accesses in the [heap] VMA. Again as far as I know, .bss mappings happen at compile time by the fronted (i.e., Clang). Where should I change, in order to filter heap accesses?