Re: [MiNT] Safe stack overflow

[Miro Kropáček <miro.kropacek@gmail.com>]

On Mon, Feb 24, 2014 at 10:20 PM, Markus Fröschle <markus@mubf.de> wrote:

Hmmm. I don’t get it.

Typical TPA looks like this:

<heap>

<stack>

<bss segment>

<data segment>

<text segment> 

Text segments lies on the lowest address, stack on the highest. Now, if a stack overflow occurs, bss and data gets overwritten. If you rearrange it like this:

<heap>

<bss segment>

<data segment>

<text segment> 

<stack>

as soon as the SP leaves the program's allocated and protected area => boom, memory violation.

You could of course use memory protection to protect the stack, but that probably would only need slight changes to your program, not necessarily to MiNT: just put the stack into a malloc’d region and make sure you don’t own adjacent memory below.

Yes, this could work too but it's more complex and fragments memory.

--
MiKRO / Mystic Bytes
http://mikro.atari.org