Hi,
I've generated (via rpmbuild) a patched version of the latest CentoS 6.2 kernel (2.6.32-220.7.1) with the imq patchset ( http://www.linuximq.net/patches.html), but this causes the kABI to break. What can orshould I do about this, if anything? What kinds of changes cause the kABI to break? Would it be reasonable to think I might be able to fix the patch to be kABI compliant? Is the kABI for CentOS the same as the one for the upstream RHEL version? Should I try to patch the kABI (as Oracle does in their unbreakable linux kernel)? What would be the procedure foir this?
I understand you can't help me with the patches or the kernel itself, but I was hoping you might help me understand the kABI well enough that I can handle things for there.
Thanks very much.
On Wed, Apr 18, 2012 at 3:44 AM, Mike Schmidt mike.schmidt@intello.comwrote:
Hi,
I've generated (via rpmbuild) a patched version of the latest CentoS 6.2 kernel (2.6.32-220.7.1) with the imq patchset ( http://www.linuximq.net/patches.html), but this causes the kABI to break. What can orshould I do about this, if anything? What kinds of changes cause the kABI to break? Would it be reasonable to think I might be able to fix the patch to be kABI compliant? Is the kABI for CentOS the same as the one for the upstream RHEL version? Should I try to patch the kABI (as Oracle does in their unbreakable linux kernel)? What would be the procedure foir this?
Yes, it's the same as the upstream's. You can either fix the code or disable the checks at your own risk.
http://wiki.centos.org/HowTos/Custom_Kernel#head-566abc4208fceb902d41ee82633... http://elrepo.org/tiki/FAQ https://bugzilla.redhat.com/show_bug.cgi?id=487763
On Wed, Apr 18, 2012 at 6:43 AM, Giovanni Tirloni gtirloni@sysdroid.comwrote:
Yes, it's the same as the upstream's. You can either fix the code or disable the checks at your own risk.
I read the information you provided, thank you very much. I as already familiar with all except the bugzilla entry. However, I still do not know exactly what kind of thing breaks the kABI, so I would not know how to identify the problem areas in the patch. Besides that, is updating the kABI a solution, or not? How the kABI mechanism works is not clearly explained from the documentation I have been able to find. Is there some documentation that describes it for kmod developers?
On Wed, Apr 18, 2012 at 2:32 PM, Mike Schmidt mike.schmidt@intello.com wrote:
I read the information you provided, thank you very much. I as already familiar with all except the bugzilla entry. However, I still do not know exactly what kind of thing breaks the kABI, so I would not know how to identify the problem areas in the patch. Besides that, is updating the kABI a solution, or not? How the kABI mechanism works is not clearly explained from the documentation I have been able to find. Is there some documentation that describes it for kmod developers?
These documents written by Jon Masters are the best source:
http://dup.et.redhat.com/presentations/DriverUpdateProgramTechnical.pdf http://people.redhat.com/jcm/el6/dup/docs/old/pre-release/whitepaper.pdf
Akemi
Akemi
On 18/04/12 07:44, Mike Schmidt wrote:
Hi,
I've generated (via rpmbuild) a patched version of the latest CentoS 6.2 kernel (2.6.32-220.7.1) with the imq patchset ( http://www.linuximq.net/patches.html), but this causes the kABI to break. What can orshould I do about this, if anything?
That all depends on whether a consistent kABI is important to you on your system. It might be perfectly acceptable to you to just build your new patched kernel and use it.
What kinds of changes cause the kABI to break? Would it be reasonable to think I might be able to fix the patch to be kABI compliant?
Typically changes to whitelisted kernel interfaces (kernel symbols) could break the kABI.
It is possible. It really depends what broke and why.
Is the kABI for CentOS the same as the one for the upstream RHEL version?
Yes.
Should I try to patch the kABI (as Oracle does in their unbreakable linux kernel)? What would be the procedure foir this?
Again, that depends (see above). You may be able to work around the breakages. The first step is to identify which whitelisted interfaces are affected.
I understand you can't help me with the patches or the kernel itself, but I was hoping you might help me understand the kABI well enough that I can handle things for there.
Thanks very much.
In addition to the reference material posted by Akemi, please also see the docs here:
http://people.redhat.com/jcm/el6/dup/docs/
Hope that helps.
Thanks for the information. I've now read the first few documents, and they are very enlightening. I'm still working on understanding, but I believe I have a start at determining what makes the imq patch break the kabi. After I figure that out, I'll see what hte next steps might be. In the meantime, I do have a running kernel that works well, so the kABI is not a showstopper right now. This is a fascinating subject. Thank you again for all your help.
Hi Mike
On 04/19/2012 05:22 AM, Mike Schmidt wrote:
the meantime, I do have a running kernel that works well, so the kABI is not a showstopper right now.
Fancy contributing ( and maintaining that ) in the CentOS Plus repo ?
On Thu, Apr 19, 2012 at 5:52 AM, Karanbir Singh mail-lists@karan.orgwrote:
Hi Mike
Fancy contributing ( and maintaining that ) in the CentOS Plus repo ?
I could do that. Even with a broken kABI? I searched everywhere for a version of CentOS with IMQ installed, but only ClearOS had that. Having it in CentOS Plus would be cool. I'll let you know after I make a serious attempt at fixing the patch for the kABI.
On 04/19/2012 01:47 PM, Mike Schmidt wrote:
Fancy contributing ( and maintaining that ) in the CentOS Plus repo ?I could do that. Even with a broken kABI? I searched everywhere for a version of CentOS with IMQ installed, but only ClearOS had that. Having it in CentOS Plus would be cool. I'll let you know after I make a serious attempt at fixing the patch for the kABI.
So, if you can get it to work with and in the plus kernel that is fine and good - but if not, it can just go in as its own kernel as well ( it just needs to be in the plus repo )
- KB
On Thu, Apr 19, 2012 at 5:47 AM, Mike Schmidt mike.schmidt@intello.com wrote:
On Thu, Apr 19, 2012 at 5:52 AM, Karanbir Singh mail-lists@karan.org wrote:
Hi Mike
Fancy contributing ( and maintaining that ) in the CentOS Plus repo ?
I could do that. Even with a broken kABI? I searched everywhere for a version of CentOS with IMQ installed, but only ClearOS had that. Having it in CentOS Plus would be cool. I'll let you know after I make a serious attempt at fixing the patch for the kABI.
If no kABI breakage, the patch could easily be incorporated in the centosplus kernel. But, yes, the kABI is a requirement for the cplus kernel.
Akemi
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Akemi Yagi -
Giovanni Tirloni -
Karanbir Singh -
Mike Schmidt -
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