Hi! > > I've no idea what the kernel should do; since you failed to answer the > > question what happens when you point this to garbage. > > > > Does it then fault or what? > > Yeah, I think you'll fault with a rather mysterious CR2 value since > you'll go look at the instruction that faulted and not see any > references to the CR2 value. > > I think this new MSR probably needs to get included in oops output when > CET is enabled. > > Why don't we require that a VMA be in place for the entire bitmap? > Don't we need a "get" prctl function too in case something like a JIT is > running and needs to find the location of this bitmap to set bits itself? > > Or, do we just go whole-hog and have the kernel manage the bitmap > itself. Our interface here could be: > > prctl(PR_MARK_CODE_AS_LEGACY, start, size); > > and then have the kernel allocate and set the bitmap for those code > locations. For the record, that sounds like a better interface than userspace knowing about the bitmap formats... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
