SharedUnixLibrary and the System Heap

John Tytgat John.Tytgat at
Mon Mar 27 13:40:25 PST 2006

In message <44285552.1060506 at>
          Matt Edgar <matt at> wrote:

> We are looking at some tightening up of the memory protection in RISC OS 
>   and one of the possibilities is to protect the system heap against 
> user  mode accesses.
> Unfortunately SUL does this, so protecting the heap would break a lot of 
> things.
> Switching to a privledged mode within SUL in order to access the heap 
> seems like a sensible solution.
> Does anyone see a problem with this? Or have a better solution? etc.

I wasn't aware that there is code in the SUL module itself executed in
user mode accessing the SVC stack (that's what you are saying, isn't it ?).

You're sure it is SUL module code and not UnixLib in application space ?
I'm willing to investigate this more but I presume you have something I
can use to protect the system heap from user mode access and see where
things are breaking ?

John Tytgat, in his comfy chair at home                                 BASS
John.Tytgat at                             ARM powered, RISC OS driven

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