On Sunday, March 30, 2003, at 7:48 PM, Brian Tabone wrote: I read the MMU overview for the PowerPC and it seems that the MMU supports fairly granular execute privileges (IE per page versus per segment), which should make implementing the non-execute stack (and perhaps non-execute data segment) simpler. I think you need to read that again. The effect of the no-execute bit is discussed on a page basis, but the bit itself is only settable at the segment level. So, you have to give up 256 MB section(s) of your address space to non-execute status, and you have to assure all stacks are in that range. That was deemed too restrictive at the time. --Jim _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.