Re: [avr-gcc-list] Improving in leaps and skips!

[Ben L. Titzer]

On Mar 13, 2005, at 1:26 PM, Jeff Barlow wrote:

> Marek Michalkiewicz <address@hidden>  wrote:
>
> > Trampolines can't work on the AVR because it is not possible to 
> > execute
> > code from writable memory.
>
> I would think they are becoming problematic on the more
> mainstream architectures also. It's been recognized that
> executing code on the stack opens the door to various security
> exploits. Newer Linux kernels, on some CPUs, are using the new NX
> bits to make data memory regions non executable.

The code to execute doesn't necessarily have to be on the stack. Java 
virtual machines dynamically generate code into the heap and execute 
it.

As a side note, Solaris / sparc has had a NX (no execute) bit for about 
a decade now. :-)
But if you ask me, buffer overflows are just embarassing--people just 
don't learn from their (or other's) mistakes. There are programming 
disciplines, languages, and runtime systems that make buffer overflows 
impossible, but....ah well...I digress.

-B
========================================================
Before we work on artificial intelligence, why don't we do something 
about natural stupidity?
--Steve Polyak