hi,

On Tue, Sep 23, 2003 at 01:05:07AM -0400, Andrew Brown wrote:
> okay...here's what (i think) is happening.
> 
> since the permissions of the stack changed (from rwx to rw- when we
> got the w^x code), there's a greater possibility of things getting
> merged with the stack (the merge code is eager to merge stuff that can
> be merged), but with the way that stack faults (ie, attempts to write
> to unmapped pages) are handled, attempting to write to something at
> the "top" (ie, the lowest address) of the stack, not incurring page
> faults in an orderly manner makes you die.

what's the actual problem with the fault handler if stack vm_map entries
are merged with non-stack ones?  it would seem better to just remove
assumptions about vm_map layout from the fault-handler code, then
merging stack and non-stack entries would be fine.  I'd rather not
special-case this if it's not necessary.

-Chuck