Re: [PATCH] fs/devfs/base.c

[Linus Torvalds]

On Sun, 27 May 2001, Richard Gooch wrote:
> 
> I absolutely don't want this patch applied. It's bogus. It is entirely
> safe to alloc 1 kB on the stack in this code, since it has a short and
> well-controlled code path from syscall entry to the function.

IT IS NEVER EVER SAFE TO ALLOCATE 1kB OF STACK!

Why?
 - automatic checkers are wonderful, and we do not want to have "oh, in
   this case it is magically ok" kinds of things.
 - the kernel stack is 4kB, and _nobody_ has the right to eat up a
   noticeable portion of it. It doesn't matter if you "know" your caller
   or not: you do not know what interrupts happen during this time, and
   how much stack they want.

Ergo: the simple rule of "don't allocate big structures of the stack" is
always a good rule, and making excuses for it is bad.

		Linus