Re: Non-executable stack
Re: Non-executable stack
- Subject: Re: Non-executable stack
- From: Justin Walker <email@hidden>
- Date: Wed, 2 Apr 2003 19:10:59 -0800
A brief reply:
On Wednesday, Apr 2, 2003, at 06:32 US/Pacific, Pelle Johansson wrote:
tisdagen den 1 april 2003 kl 05.54 skrev Jim Magee:
Out of curiosity, I've always wondered why the ABI grows the stack
downwards. It seems to be just as easy to grow it upwards, which would
make buffer overflows much harder, if not impossible.
Habit, mostly, I think. Most of this stuff grew up on PDP11's, and the
PDP11 architecture gave downward growing stacks (among other things,
interrupts and subroutine calls predecremented stack pointers; and the
register specifiers in instructions made it easy to 'comply' with that
mode of operation). With modernXXXmore recent architectures like
PowerPC where a stack is more ABI than ISA, you can, as it were, go
either way (:-}).
Regards,
Justin
--
Justin C. Walker, Curmudgeon-At-Large *
Institute for General Semantics | It's not whether you win or
lose...
| It's whether *I* win or lose.
*--------------------------------------*-------------------------------*
_______________________________________________
darwin-kernel mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/darwin-kernel
Do not post admin requests to the list. They will be ignored.