Re: Is PIE randomization breaking klibc binaries?

[Jiri Kosina <jkosina@suse.cz>]

On Thu, 2 Aug 2007, H. Peter Anvin wrote:

> Yup... it should probably be pointed out the reason the old kernel 
> worked was nothing but pure dumb luck.  This was a GNU ld change which 
> needed to be undone for klibc.  It's unfortunate that stock x86-64 
> binaries leave as little of a null pointer range as they do, but that's 
> life, unfortunately.  The other alternative is to map klibc just below 
> the 2 GB point, which would also work, but the old way broke when the ld 
> change went in.  As previously stated, klibc-1.4.35 or higher fixes 
> this.

Thanks for pointing this out. So it seems that maybe the mainline revert 
of pie-randomization.patch was a little bit premature. Bret -- could you 
please clarify whether you have experienced also klibc-related segfaults 
with pie-randomization.patch applied, or you have had just random binaries 
segfaulting, as you pointed out here: http://lkml.org/lkml/2007/7/21/31

Seems like you are also using ubuntu, same as Ulrich, so you might have 
been hitting the very same behavior of klibc-1.4.

Thanks in advance for clarifying this, so that I can eventually resubmit 
the pie-randomization patch.

Thanks,

-- 
Jiri Kosina
SUSE Labs
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