nested page-faulting of user-space address in Linux
- by shankar
Hi,
I would like to know if it is functionally wrong to page-fault a user-space address when kernel is running fault-handler to bring in a user-page.
OS is Linux 2.6.30
Assume that both user-addresses are valid ( falling within vma , rw permission ) for the task.
When I check the kernel code, i find that the kernel does not mind the nested fault
if the faulted-addresses are valid and the fault did not occur in atomic-context or in irq handler.
(I dont think the answer is cpu-specific, but I would add that i am interested in
arm and mips ).
eg : The scenario can happen if I print stack-data from page-fault handler.
thanks
shankar