[perl #54120] [PATCH] [metaconfig] Need more -fstack-protector

On Tue May 20 08:33:30 2008, hmbrand wrote:
> On Tue, 20 May 2008 11:21:14 -0400 (EDT), Andy Dougherty
> <doughera@lafayette.edu> wrote:
> 
> > On Tue, 20 May 2008, Nicholas Clark via RT wrote:
> >
> > [patch to fiddle with -fstack-protector]
> >
> > > : flags used in final linking phase
> > > case "$ldflags" in
> > > '') if ./venix; then
> > > 		dflt='-i -z'
> > > 	else
> > > 		dflt=''
> > > 	fi
> > > 	case "$ccflags" in
> > > 	*-posix*) dflt="$dflt -posix" ;;
> > > 	esac
> > > 	# See note above about -fstack-protector
> > > 	case "$ccflags" in
> > > 	*-fstack-protector*) dflt="$dflt -fstack-protector" ;;
> > > 	esac
> > > 	;;
> > > *) dflt="$ldflags";;
> > > esac
> > >
> > >
> > > I find that as soon as I use -Aldflags, I don't get
> -fstack-protector added.
> > > Which is somewhat daft, at least as an "end user", as I was using
> *A* not *D*.
> >
> > Oops.  That's not supposed to happen.  Sorry about that!
> >
> > There are actually two separate things going on here:  First, the -A
> is
> > supposed to happen after platform-specific hints are done.  By the
> time
> > we've reached this code, platform-specific hints have long been
> finished,
> > so the -A should indeed have been applied.
> >
> > The troublesome bit of code I quoted above is there to allow a use
> to tell
> > Configure:  "use this exact string for ldflags, don't mess with it
> at
> > all."  The thinking pre-dates Configure's -A flag. That's not what
> you
> > wanted to do, however.
> >
> > > I don't understand the implementation of Configure enough to know
> when -A
> > > processing is done, but is it done early enough that ldflags is
> already set by
> > > the time that that code above is reached?
> >
> > Yes, that's exactly it.  And further, we've also lost all memory of
> > whether it was a -A or a -D addition.
> >
> > Clearly, that's a problem.  I'll need to think on it a bit to figure
> out
> > how to fix it.  I think the short-term fix will be to add
> > -fstack-protector no matter what.  Something like this (sorry no
> > metaconfig patch here, but it should apply with a (large) offset)
> 
> Hunk #1 succeeded at 377 (offset -4884 lines).
> 
> The regenerated Configure seems to be under just a bit more impact.
> Regenerated in #33887
> 
> > --- perl-current/Configure	2008-05-17 10:31:35.000000000 -0400
> > +++ perl-andy/Configure	2008-05-20 11:11:41.000000000 -0400
> > @@ -5261,13 +5261,18 @@
> >  	case "$ccflags" in
> >  	*-posix*) dflt="$dflt -posix" ;;
> >  	esac
> > -	# See note above about -fstack-protector
> > -	case "$ccflags" in
> > -	*-fstack-protector*) dflt="$dflt -fstack-protector" ;;
> > -	esac
> >  	;;
> >  *) dflt="$ldflags";;
> >  esac
> > +# See note above about -fstack-protector
> > +case "$ccflags" in
> > +*-fstack-protector*)
> > +	case "$dflt" in
> > +	*-fstack-protector*) ;; # Don't add it again
> > +	*) dflt="$dflt -fstack-protector" ;;
> > +	esac
> > +	;;
> > +esac
> >
> >  : Try to guess additional flags to pick up local libraries.
> >  for thislibdir in $libpth; do
> >
> 


This has gone in with changes #33886 (metaconfig) and #33887 (Configure)

• [perl #54120] [PATCH] [metaconfig] Need more -fstack-protector by Steve Peters via RT