Bug 5710

Summary:	DRI libs relocation problems on hardened systems
Product:	DRI	Reporter:	Declan Moriarty <junk_mail>
Component:	libGL	Assignee:	Default DRI bug account <dri-devel>
Status:	RESOLVED DUPLICATE	QA Contact:
Severity:	normal
Priority:	high
Version:	unspecified
Hardware:	x86 (IA32)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:

Description Declan Moriarty 2006-01-25 00:24:48 UTC

On hardened systems (Such as Hardened Linux From Scratch) the Pax kernel patches
provide an option CONFIG_PAX_NOELFRELOCS, which does what it says on the tin,
and you can't relocate elf executables. The DRI faile under X-6.9.0 with (from
memory)

"Error loading shared library /usr/X11R6/lib/libGL.so.1
Error opening shared library for relocation: Permission denied"

I am attaching a check of the X libraries. I went to some trouble to try a
precompiled libGL.so (from common-20051220-linux-i386/) and a correctly compiled
version from Xorg-6.9.0 I checked, and got these relocations

TEXTREL in exe /usr/X11R6/lib/dri-old.libGL.so.1.2
TEXTREL in exe /usr/X11R6/lib/libGL.so.1.2
TEXTREL library /usr/local/lib/libGL.so.1 exec /usr/X11R6/lib/libGLU.so.1.3
TEXTREL in exe /usr/X11R6/lib/libOSMesa.so.4.0
TEXTREL library /usr/local/lib/libGL.so.1 exec /usr/X11R6/lib/libOSMesa.so.4.0

On my system,dri-old.libGL.so.1.2 is the precompiled one from common-20051220,
and the other is from Xorg-6.9.0. Precompiled stuff will never work on hardened
systems, BTW. They really need no compile their own software. 
The other dri archive in the frame is radeon-20051220

Comment 1 Declan Moriarty 2006-01-25 22:10:09 UTC

That error should be: "Cannot make segment writable for relocation. Permission
denied"

I have this refined somewhat. Reading the readme in the et_dyn.tar.gz file
referenced in the kernel help (under CONFIG_PAX_NOELFRELOCS) indicates that it
is the -pie option in gcc which is causing trouble. This position independent
feature is nobbled by any text relocations, which, apparently fix a position.

     Inserting '-no-pie' where I thought it would help (in the many GL
directories) got me a version of libGL.so.1.2 with no TEXTRELs. I have not to
date got a version of any of the following without text relocations. 

     glxinfo     glsgears   xdriinfo   radeon_drv.so

Compiler options are tricky on hardened systems, as the compiler throws a set of
hardening options by default, some of which can be overridden by command line stuff

On Xorg-6.9.0, this turns out to be an X problem and may advantageously be
labelled as such by someone handling it.

Comment 2 Declan Moriarty 2006-01-26 03:38:07 UTC

The full list of problem programs & libs are all linked against libGL.so.1,
which (I must correct myself) contains a Textrel.
http://www.linuxfromscratch.org/hlfs/view/unstable/glibc/chapter02/pie.html

/wallows out of his depth, then gradually sinks.

Comment 3 Michel Dänzer 2006-01-26 03:50:47 UTC

See bug 4197.

Comment 4 Declan Moriarty 2006-01-26 04:12:08 UTC

This is a duplicate of 4197, it appears. Thanks for that.

From reading the vitriol on bug 4197, the patch attached carries a performance
penalty and a mixed blessing, but works. I'll shoehorn it in and try it.

*** This bug has been marked as a duplicate of 4197 ***

Comment 5 Declan Moriarty 2006-01-26 20:37:22 UTC

The mesa take 2 patch from bug 4197 fixes the issue. DRI now works here. Thanks.

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