Re: Recent Changes to WITH_*/WITHOUT_* in src

On May 10, 2014 02:14 PM -0600, Warner Losh wrote:
> 
> On May 10, 2014, at 10:45 AM, Shawn Webb <lattera_at_gmail.com> wrote:
> 
> > Hey All,
> > 
> > It seems that the recent changes to the makefiles for building
> > world/kernel have broken some modifications I have locally for
> > implementing ASLR+PIE. I'm quite the bsd make newbie, so I thought I'd
> > ask for a bit of help. I'm sure the solution is quite simple.
> > 
> > My code is up on GitHub. I'll include links at the bottom of the email.
> > 
> > The code in question is in share/mk/bsd.prog.mk, where I'm checking to
> > see if MK_PIE is not equal to "no". Prior to the recent changes, this
> > code used to work. (Please note that I know that the way I'm cheking is
> > a bit bloated, if anyone has any suggestions to trim my code down, let
> > me know).
> 
> You?ll need to add PIE to DEFAULT_NO_OPTIONS in bsd.opts.mk since
> bsd.*.mk files need it.
> 

Thanks a lot! Adding it to that one worked.

But what's the difference between the DEFAULT_NO_OPTIONS in src.opts.mk and
bsd.opts.mk?

> > How this feature is supposed to work is:
> > 1) PIE is added to the __DEFAULT_NO_OPTIONS to make building
> > applications as position-independent executables opt-in.
> > 2) User adds WITH_PIE=1 to /etc/src.conf or /etc/make.conf
> > 3) The application being built needs to also specify CAN_PIE=1 in its
> > Makefile. This is because some applications don't support being built as
> > a position-independent executable.
> > 4) If MK_PIE is not "no" and CAN_PIE is defined, then add additional
> > CFLAGS.
> > 
> > The log from my build is here: http://ix.io/cf0
> > 
> > My code is here:
> > https://github.com/HardenedBSD/hardenedBSD/blob/hardened/current/aslr/share/mk/bsd.prog.mk#L14-L22
> 
> Maybe RESCUE should define NO_SHARED=yes since it is building a
> static binary so you can eliminate a special case that infects the bsd.*.mk files
> with defines from our src build?
> 

That sounds like a good idea. Since that's outside the scope of my ASLR
work, should I file a PR for that?

> Hate that you are propagating the NO_SHARED=no interface, but can?t
> offer at better suggestion at the moment. I?d kinda like to kill that?

In looking at the Makefiles, it seems like NO_*/YES_* is being phased
out. Once a suitable alternative to NO_SHARED is in place, I'll make
adjustments on my end.

Thanks,

Shawn