notify_page_fault() problem

[Andi Kleen]

Quentin Barnes <qbarnes@urbana.css.mot.com> writes:

> Now on i386's do_page_fault(), it avoids the above infinite
> recursion by checking to see if the fault happened in kernel space.

Actually the real avoidance is by calling vmalloc_sync_all() when
the notifier is registered. Probably you need to implement an equivalent
for ARM

> One thing I don't understand is why notify_page_fault() is called
> so early in everyone's page fault handling code. 

So that users like kprobes don't deadlock on a fault inside
a region that takes the mm_sem (or some other lock taken by pf)

-Andi