Subject: Re: issues w/init

From: Benjamin Herrenschmidt <[email-masked]>
Date: Fri, 17 Apr 2009 09:38:27 +0200

On Thu, 2009-04-16 at 14:27 -0500, Kumar Gala wrote:
> On Apr 16, 2009, at 2:25 PM, Scott Wood wrote:
> 
> > Kumar Gala wrote:
> >> [root:~] cat /proc/1/maps
> >> 00100000-00103000 r-xp 00100000 00:00 0          [vdso]
> >> 0feab000-0ffbe000 r-xp 00000000 00:0d 7127086    /lib/libc-2.2.5.so
> >> 0ffbe000-0ffcb000 ---p 00113000 00:0d 7127086    /lib/libc-2.2.5.so
> >> 0ffcb000-0ffeb000 rw-p 00110000 00:0d 7127086    /lib/libc-2.2.5.so
> >
> > IIRC, this libc is old enough to execute out of non-exec memory in  
> > some cases.
> 
> Yeah, I'm going to that realization.  The question is are we ok with  
> breaking older versions of libc like this.

I'm pretty sure they are broken already when running off a 64-bit
kernel, but yeah, as I said, we may want a .config option to enable
support for that old junk which also disables support from per-page
execute permission.

Ben.