Re: loadable modules

David S. Miller (
Thu, 2 May 1996 23:05:29 -0400

From: Alan Cox <>
Date: Thu, 2 May 1996 17:52:37 +0100 (BST)

> There are reasons I do not want to do this with libc - basically, a libc
> approach can be bypassed with static bins, which I cant allow in this case.

In which case you'll need to modify the actual kernel. The syscall map is
static and its a very dangerous thing to play with as you shouldnt assume
its just going to be a vector table. We pull tricks already - eg the sparc
uses the low bit of the vector to indicate a call it can skip the expensive
window saving on.

Although Alan's points are valid, I'm getting rid of that low-bit
"feature" because after optimizing the trap entry/exit code last night
I decided the complexity/performance-gain ratio didn't warrant the

David S. Miller