Re: top stack (l)users for 2.5.69

Richard B. Johnson
2003-05-07T19:07:07Z

On Wed, 7 May 2003, Davide Libenzi wrote:

> On Wed, 7 May 2003, Richard B. Johnson wrote:
>
> > No, No. That is a process stack. Every process has it's own, entirely
> > seperate stack. This stack is used only in user mode. The kernel has
> > it's own stack. Every time you switch to kernel mode either by
> > calling the kernel or by a hardware interrupt, the kernel's stack
> > is used.
>
> Is it your understanding that does not exist a per task kernel stack ?
>

It is my understanding that there is one kernel stack. If there
is a stack allocated for some "transition", and I guess there
may be, because of the mail I'm getting, then it has absolutely
no purpose whatsoever and is wasted valuable non-paged RAM.

The reason why system-call parameters are passed in registers
is so that we didn't have the overhead of copying stuff from a
user stack to a kernel stack.

Does anybody know (not guess) if this was stuff added for the
new non-interrupt 0x80 syscall code? I want to know how a
simple kernel got corrupted into this twisted thing.

Anybody who has a copy of any of the Intel manuals since '386
knows that there needs to be only one kernel stack.

Cheers,
Dick Johnson
Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips).
Why is the government concerned about the lunatic fringe? Think about it.