PCH and exec-shield...

[law@redhat.com]

In message <1078254320.3736.26.camel@dzur.sfbay.redhat.com>, Eric Christopher w
rites:
 >On Tue, 2004-03-02 at 11:01, David Daney wrote:
 >> Using a recent 3.4.0 snapshot, I found that most of the PCH testsuite 
 >> has random failures when run on a machine that has the exec-shield 
 >> "feature" (Fedora Core 1 and probably RH9 also).
 >> 
 >> It was pointed out to me that putting the following in my 
 >> /etc/sysctl.conf file would fix the problems:
 >> 
 >> # Turning off exec shield.
 >> kernel.exec-shield = 0
 >> kernel.exec-shield-randomize = 0
 >> 
 >> I searched through the info pages as well as 
 >> http://gcc.gnu.org/gcc-3.4/changes.html and found no mention of this.
 >> 
 >> Is this documented anywhere?
 >
 >I think I've seen it documented on the fedora release notes, but i could
 >be wrong.
That matches my recollection as well.

 >If it isn't, it probably should be there as well. I think a
 >change to changes.html for 3.4 would be good for this - perhaps in the
 >PCH section.
Yes, that would probably be wise.

Alternately, I believe we could have the build process mark cc1plus and
friends as not needing/wanting the exec-shield functionality.  IIRC there
is a program you can run which twiddles bits in the ELF headers/sections
which allow you to control exec-shield on a per-binary basis.

jeff