Re: Minutes from Feb 21 LSE Call

Linus Torvalds
2003-02-23T21:38:13Z

On Sun, 23 Feb 2003, John Bradford wrote:
>
> I could be wrong, but I always thought that Sparc, and a lot of other
> architectures could mark arbitrary areas of memory, (such as the
> stack), as non-executable, whereas x86 only lets you have one
> non-executable segment.

The x86 has that stupid "executablility is tied to a segment" thing, which
means that you cannot make things executable on a page-per-page level.
It's a mistake, but it's one that _could_ be fixed in the architecture if
it really mattered, the same way the WP bit got fixed in the i486.

I'm definitely not saying that the x86 is perfect. It clearly isn't. But a
lot of people complain about the wrong things, and a lot of people who
tried to "fix" things just made them worse by throwing out the good parts
too.

Linus