On Fri, 2002-09-27 at 18:26, Linus Torvalds wrote:
> 
> On Fri, 27 Sep 2002, Ingo Molnar wrote:
> > 
> > the attached patch implements the virtual => physical cache. Right now
> > only the COW code calls the invalidation function, because futexes do not
> > need notification on unmap.
> 
> Ok, looks good. Except you make get_user_page() do a write fault on the 
> page, and one of the points of this approach was that that shouldn't even 
> be needed. Or did I miss some case that does need it?

get_user_page() cannot/should not ever do a pagefault via the pagefault
code otherwise the coredump code will take the mmap semaphore
recursively and deadlock.