Messages in this thread | | | Subject | Re: Arch specific mmap attributes (Was: mprotect pgprot handling weirdness) | From | Benjamin Herrenschmidt <> | Date | Tue, 06 Apr 2010 17:30:44 +1000 |
| |
On Tue, 2010-04-06 at 15:24 +0900, KOSAKI Motohiro wrote:
> I guess you haven't catch my intention. I didn't say we have to remove > PROT_SAO and VM_SAO. > I mean mmap(PROT_SAO) is ok, it's only append new flag, not change exiting > flags meanings. I'm only against mprotect(PROT_NONE) turn off PROT_SAO > implicitely. > > IOW I recommend we use three syscall > mmap() create new mappings > mprotect() change a protection of mapping (as a name) > mattribute(): (or similar name) > change an attribute of mapping (e.g. PROT_SAO or > another arch specific flags) > > I'm not against changing mm/protect.c for PROT_SAO.
Ok, I see. No biggie. The main deal remains how we want to do that inside the kernel :-) I think the less horrible options here are to either extend vm_flags to always be 64-bit, or add a separate vm_map_attributes flag, and add the necessary bits and pieces to prevent merge accross different attribute vma's.
The more I try to hack it into vm_page_prot, the more I hate that option.
Cheers Ben.
| |