Re: Worst recursion in the kernel

[David Hinds <dhinds@sonic.net>]

On Wed, Dec 03, 2003 at 03:08:32PM -0800, Mike Fedyk wrote:
> On Wed, Dec 03, 2003 at 10:57:43PM +0000, Russell King wrote:
> > Yes, but the condition of the /data/ is such that it will not recurse.
> > 
> > A pure "can this function call that function" analysis ignoring the
> > state of the data will say this will infinitely recuse.  Include
> > the data, and you'll find it has a very definite recursion limit.
> 
> Is the data verified?

Russell is using "data" loosely.  Basically the logic goes like this:

read_cis_mem():
  if sys_start is NULL then call validate_mem()

validate_mem():
  set sys_start
  call stuff that calls read_cis_mem()

so the functions do not require consistency of any external program
data to avoid recursion.

-- Dave