[fpc-pascal] Validate heap/stack addresses

Anthony Walter sysrpl at gmail.com
Tue Dec 1 18:51:22 CET 2009

On Tue, Dec 1, 2009 at 11:58 AM, Bruce Bauman
<bruce.bauman at andesaservices.com> wrote:
> I’m trying to port/debug some ugly Pascal code.
> Is there a way I can tell if an arbitrary address is within the heap or
> stack?

Without hooking/replacing the memory manager, I don't believe you can
handle memory tracking this information. And even if you did hook
replace the memory manager it would still fail in places where you
interface with shared libraries that handle their own memory

If don't mind using OS specific functions, Windows provides ways to
query process memory base address range and memory querying (which
returns the number of consecutive pages available for writing). For
that look at GetSystemInfo for memory page information, OpenProcess
with memory query flags (if you don't have the rights use
AdjustTokenPrivileges), and VirtualQueryEx to find consecutive valid
memory pages. I believe VirtualQueryEx works upon all process system
memory (code/stack/heap).

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