Re: prelink issue with ppc64?

[Mark Hatle <mark.hatle@windriver.com>]

On 8/3/11 9:53 AM, Kumar Gala wrote:
> 
> On Aug 3, 2011, at 9:37 AM, Mark Hatle wrote:
> 
>> On 8/3/11 12:35 AM, Kumar Gala wrote:
>>> If prelink gets a chance to properly run I get a rootfs that does:
>>>
>>> /sbin/init: relocation error: /lib64/libc.so.6: symbol _rtld_global_ro, version GLIBC_PRIVATE not defined in file ld64.so.1 with link time reference
>>>
>>> if 'baselib' is set to /lib we get:
>>>
>>> /local/home/galak/git/poky/build-p5020/tmp/sysroots/x86_64-linux/usr/sbin/prelink: /sbin/init.sysvinit: Using /lib/ld64.so.1, not /lib64/ld64.so.1 as dynamic linker
>>>
>>> if 'baselib' is set to /lib64 we get:
>>>
>>> Assigned virtual address space slots for libraries:
>>> /lib64/ld64.so.1                                             00000080f4910000-00000080f49473d0
>>> /lib64/libc.so.6                                             00000080f4950000-00000080f4afe090
>>> /lib64/libdl.so.2                                            00000080f4b10000-00000080f4b23520
>>> /lib64/libcrypt.so.1                                         00000080f4b10000-00000080f4b57708
>>> /lib64/libutil.so.1                                          00000080f4b10000-00000080f4b234a0
>>> Would prelink /lib64/ld-2.13.so
>>> Would prelink /lib64/libc-2.13.so
>>>
>>> Not sure what prelink is doing but it seems to breaking things.  Any ideas?
>>>
>>> ---
>>>
>>> I'm also concerned that we use /etc/prelink.conf when invoking prelink.
>>
>> Prelinker is being run within the rootfs, so the /etc/prelink.conf being used is
>> the one inside of the image -- NOT the system version.
> 
> Is this because of psuedo or something else?

In the cross prelinker, we pass in the --root=<image>.  This instructs the
cross-prelinker to prefix <image> to most paths.

>> I would suspect that the cross-prelinker rtld emulation is likely setup for the
>> LSB style library paths and may be causing some of the problems.

You can run the cross-prelinker's rtld emulation by running the prelink-rtld
program located in build/tmp-eglibc/work/x86_64-linux/usr/sbin/prelink-rtld

Passing --root=<path> will setup the sysroot path for reference, adding in
--target-paths will allow you to pass further arguments as referenced on the
sysroot.

So prelink-rtld --root=/foo/bar/build/sysroot/image --target-paths /sbin/init

Should give you back an ldd like syntax within the sysroot, for /sbin/init.
(without --target-paths, you need to specify the full path to the /sbin/init..
this is useful when running the rtld against items outside of the image.)

>>
>> I'd suggest simply disabling prelink and getting everything to work first.. once
>> it does we can work through any prelinker issues.  (Prelink on PPC64 hasn't been
>> tested within the oe-core environment.. so it could very well have issues beyond
>> the ld.so path.)
> 
> Everything else is working, so prelink is what fails for me (at least for a simple minimal) build.
> 
> any suggestions on how to try and debug further, who might be more familiar with prelink and what its doing?  When I ran readelf -a on ld-2.13.so after prelink was getting weird results, not sure if thats normal or not.

I'm the prelink maintainer for Yocto, however I know more about the way the
cross-prelinker functionality works then how the ELF specific prelink functions
work.  I've been relying on the upstream prelink project to manage the
individual architecture/ABI prelink standards.

My suggestion is to disable cross-prelinking, and revert to the upstream prelink
project -- run the binary on the target and see if it fails in the same way.  If
it does, then we know it's a deeper problem then the cross prelink integration.

You can pull down the git repository:  git://git.yoctoproject.org/prelink-cross.git

The "master" branch is identical to the upstream SVN branch.  The
"cross_prelink" branch is the current state of integration.

--Mark

> - k
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