Kernel oops while duming user core.

[Scott Wood]

Scott Wood wrote:
> Nathan Lynch wrote:
>> Is the crashing program multithreaded?  The first report had firefox
>> triggering the oops.
> 
> OK, I've got a test program that triggers it now.  I'll see if I can 
> figure out what's going on.

The problem seems to be that update_mmu_cache() is called on a guard 
page with no access rights.

Changing update_mmu_cache() to always call flush_dcache_icache_page() 
fixes it, though a better performing fix would probably be to add an 
exception table entry for the dcbst.

-Scott