[PATCH RFC v3 2/4] mm: userfault: return VM_FAULT_RETRY on signals

2018-11-20 Thread Peter Xu
There was a special path in handle_userfault() in the past that we'll return a VM_FAULT_NOPAGE when we detected non-fatal signals when waiting for userfault handling. We did that by reacquiring the mmap_sem before returning. However that brings a risk in that the vmas might have changed when we

[PATCH RFC v3 2/4] mm: userfault: return VM_FAULT_RETRY on signals

2018-11-20 Thread Peter Xu
There was a special path in handle_userfault() in the past that we'll return a VM_FAULT_NOPAGE when we detected non-fatal signals when waiting for userfault handling. We did that by reacquiring the mmap_sem before returning. However that brings a risk in that the vmas might have changed when we