svn commit: r226343 - head/sys/vm

[John Baldwin]

On Thursday, October 13, 2011 4:13:10 pm Marcel Moolenaar wrote:
> 
> On Oct 13, 2011, at 12:09 PM, Kostik Belousov wrote:
> 
> > On Thu, Oct 13, 2011 at 11:30:12AM -0700, Marcel Moolenaar wrote:
> >> 
> >> On Oct 13, 2011, at 11:20 AM, Kostik Belousov wrote:
> >> 
> >>> The two commits removed NX support for .data/.bss for 32bit binaries
> >>> Thon amd64. is is too unfortunate. Can we claim that only old
> >>> Thbinaries need this hack ?
> >> 
> >> I don't know. When did our ABI for i386 change to have NX by default?
> > I think it changed de-facto when NX appears to be supported by hardware.
> > In other words, PF_R->PF_X was always considered a coincident, and not
> > a promise.
> 
> That's really besides the point. ABI changes are made deliberately
> and ABIs must be well-documented for anyone to adhere to it. You
> can't post hoc wave your hand and say that at some unspecified time
> in the past the ABI changed: at what precise time does "supported
> by hardware mean" and how does that tie to a major FreeBSD version?
> 
> Point in case: the JDK 1.4.x still works on FreeBSD 9.x (i386), so
> the ABI really hasn't changed at all in that respect.

I think if you booted a FreeBSD 9.x i386 PAE kernel you'd find that the
jdk did not work.  That will be true for any i386 PAE kernel back to
when PG_NX support was introduced.

-- 
John Baldwin