On Mon, Feb 06, 2023 at 02:51:18AM +0000, Matthew Wilcox wrote: > That wasn't what I meant. I meant putting VM_FAULT_BADMAP and > VM_FAULT_SIGSEGV in mm_types.h. Not having "Here is a range of reserved > arch private ones". VM_FAULT_SIGSEGV is there already; I assume you meant adding them all directly into vm_fault_reason. Then I don't think it's a good idea.. Currently vm_fault_reason is a clear interface for handle_mm_fault() for not only arch pffault handlers but also soft faults like GUP. If handle_mm_fault() doesn't return VM_FAULT_BADMAP at all, I don't think we should have it as public API at all. When arch1 people reading the VM_FAULT_ documents, it shouldn't care about some fault reason that only happens with arch2. Gup shouldn't care about it either. Logically a new page fault handler should handle all the retval of vm_fault_reason afaiu. That shouldn't include e.g. VM_FAULT_BADMAP either. Thanks, -- Peter Xu
